Technical Papers

Technical Abstracts 1991-1999

Abstracts 2010-Current          Abstracts 2000-2009

Below are abstracts of technical papers presented at the Polyurethane Foam Association Technical Sessions. Papers are prepared from materials submitted for the Technical Proceedings with the permission of the individual authors who are solely responsible for their content. The content has not been subjected to peer review. The PFA does not endorse or recommend the proprietary products or processes of any manufacturer. The PFA assumes no responsibility for the accuracy or use of the information presented.

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Proceedings of the Polyurethane Foam Association Technical Program
October, 1999

F99001 Recent Developments in POSTech® Polymer Polyols, S. S. Chin, Mark M. H. A. Boelens and R. Aerts, Shell Chemical Co.

 

The flexible polyurethane foam industry is constantly challenged to provide cost-effective solutions that provide improved foam performance. End use customers want higher load bearing foams for slabstock applications, and improved comfort and durability for high resilience foam applications. In molded foam, cost effective improvements are required for improved processing and durability at lower density. Additionally, foam aesthetics are important in certain applications.

Polymer polyols have played an important role as a cost effective, versatile raw material that improves various aspects of foam performance. Recently, Shell Chemical Co. introduced POSTech polyols which contain “all-polystyrene” dispersions, to provide an additional raw material option for foamers. Since their introduction, POSTech polymer polyols have been widely accepted and used in commercial flexible foam systems. This paper reviews the recent developments in the use of POSTech polymer polyols in conventional and HR slabstock foam. Included in the paper is a predictive program for POSTech polymer polyol based HR foam, which further extends the utility of this class of polymer polyols

The author also reviews the development and properties of Caradol MD32-04 for molded foams. This unique POSTech polymer polyol is optimally designed for use in CCMTDI-based automotive seating. Caradol MD32-04 allows the production of intermediate hardness high resilience foams with a wide processing latitude, superior tear strengths, shorter demold times as well as excellent foam durability.

F99003 Next Generation Fire Retardants, Non-Halogen-High Efficiency, L. Bradford, B. Williams, E. Pinzoni, Akzo Nobel Functional Chemicals, LLC

The need for new non-halogen flame retardants, with low fogging properties, and increased efficiency has been discussed often over recent years. Following a five-year study, Akzo Nobel will introduce three new products in the year 2000 to address these needs. The new products have high phosphorus levels to achieve very good FR efficiency.

Data, collected from a large database developed to determine the efficiency of a number of FR’s in polyurethane foams at various densities, is shown in this paper. The new products are Fyrol® PNX, Fyrol® TNX and Fyrol® CLP. Fyrol PNX and Fyrol TNX are non-halogenated high efficiency fire retardants designed for use in flexible urethane foam. Fyrol CLP is a high efficiency FR containing chlorine, but at a reduced level. Fyrol PNX is the experimental product identified in earlier PFA and SPI papers on fogging as ONRI, an oligomeric non-reactive material containing 19 % phosphorous.

 The purpose of this introductory paper is to provide guidance to identify where each product will be most cost effective. The addition of this next generation of phosphorous flame retardants gives foamers the choice of reducing or eliminating halogens from most of their products. This protects against all pending and anticipated restrictions worldwide.

F99005 Latest Developments in Carbon Dioxide Technologies for the 21st Century, T. Griffiths, Cannon Viking

 Cannon started research into carbon dioxide as an alternative blowing agent to CFC 11 more than ten years ago. Carbon dioxide was a very logical choice since it was already part of the foam reaction, and it was environmentally very acceptable. The one major problem that was encountered with carbon dioxide was the high pressure required to keep it dissolved in the foam reactants during mixing. A controlled method of reducing pressure was required to prevent the foam from collapsing or developing a lot of holes. The key area for development, therefore, was a device for controlling the pressure drop. By the early 1990’s this had resulted in the principle of the CarDio gatebar which used a slot as the method of reducing pressure. This development was responsible for the sale of more than forty CarDio plants worldwide by 1999.

The pressure drop caused by the gatebar is determined by the slot height. Normally this dimension is fixed before starting the run and cannot be changed during the run. If only one grade of foam is produced, this is not a problem. However, if a large number of grades need to be produced on the same run, compromises may need to be made. A gatebar with a variable slot height would enable pressure and nucleation conditions to be optimized for each foam grade in the run. Cannon now has such a device.

The height of the slot is controlled up or down by hydraulic pressure, and can be quickly and precisely adjusted by turning a control knob. An adjustment range of around 150 micron / 0.006″ can be obtained during running.

The advantages of having a gatebar with a variable slot height are: gatebar pressure independent of output, optimized run conditions for each grade, and even wider range of carbon dioxide levels.

Cannon has also developed a CarDio Airless system. This is achieved by the addition of a zone of “Controlled turbulence” + Velocity reduction, after the pressure drop zone. This new part of the gatebar design induces nucleation with 60 % less nucleating gas. The result is a uniform froth with no voids.

F99002 New FR Silicone Stabilizer For CO2 Technology, A. Melle, MC. Desnier, SA Meyrin, D. Dounis, L. Lawler S. Mc Vey, CK Witco Corp.

The first process to use carbon dioxide as auxiliary blowing agent to replace more hazardous materials was introduced in 1992. In the seven years since that introduction at least three distinct continuous processes and at least one discontinuous process are competing for global market share. Likewise, flexible polyurethane foam (FPF) additive suppliers have competed for business in this new market segment. The FPF conventional silicone surfactant market in North America was dominated by Niax® silicone L-620, and later L-618 when these new processes were introduced. While these two silicone surfactants perform well for the manufacture of FPF using no auxiliary blowing agents (ABA), or blowing agents other than carbon dioxide, they result in poor performance when carbon dioxide is used.

Witco quickly identified which silicones in their product portfolio were adequate for the production of foams made with carbon dioxide as ABA. Where flame retardancy (FR) is not an issue, Niax silicone L-580 was found to be an excellent material where non-hydrolyzable products are preferred. Niax SC-155, a hydrolyzable, non-FR material has consistently demonstrated superior cell structure performance to any other material. Where FR performance is required either L-5770 or L-603 could be used, though neither product was optimum.

After considerable research, Witco was able to define a FR silicone surfactant for use with carbon dioxide systems. The new surfactant is called Niax silicone L-631. The performance characteristics of L-631 are described in detail in this paper.

F99004 The Physics of Flexible Slabstock Foam, Tyler Housel, Inolex Chemical Co.

 Polyurethane foam was developed in the 1950’s by pioneering researchers who learned how to control an unwanted side reaction and turn it into a viable commercial process. Throughout the years, the art has been advanced by countless other scientists and engineers into an enterprise of global proportions. Intuition, experimentation, and serendipity have fueled the development of flexible polyurethane foam (FPF), but beneath it all lies a set of basic physical principles. The purpose of this paper is to outline the physics that describes how a mixture of liquid chemicals can develop into a matrix of solid polymer with uniform, flexible, cellular structure.

 The foaming process is broken down into five stages: raw material conditioning, mixing, growth, cell opening and cure. Different physical principles describe the events in each stage, and these are defined as they come up. The description of the events that occur are not presented in a very formal or exhaustive manner, but are only meant to convey a sense of what is happening and why. The work presented in the paper is not original, and the author is indebted to all who have discussed the topic in the literature and in person to further his understanding. It is hoped that the extensive references provided will result in deeper study in areas of interest.

F18006 A New Silicone Surfactant for Use in Carbon Dioxide Technology, D. H. Ridgway, J. G. Kniss, and L. A. Mercando

 

The adaptation of the Montreal Protocol in 1987 and new restrictions on the use of methylene chloride by OSHA have meant the flexible polyurethane foam (FPF) industry has had to find new methods of producing low-density foams at the desired hardness level. Additional pending restrictions by the EPA has heightened the search for viable substitutes.

Alternative auxiliary blowing agents such as acetone and pentane and mechanical forced cooling technologies have helped to fill the gap left by the demise of the industry’s traditional use of methylene chloride. To date, the most widely accepted of the new technologies is blowing foam with liquid carbon dioxide. At least three different machine configurations have been introduced into the FPF industry, and are being used to produce foam commercially. These liquid carbon dioxide technologies are the CO-2™ process by Beamech, the Cardio® process by Cannon, and the Novaflex™ process by Hennecke.

As is common with all new technologies, production problems have been encountered which prevent carbon dioxide blown foam technology from being universally accepted. Some of the most persistent and troublesome shortcomings of these technologies, such as poor cell structure and striations, can be remedied by the proper choice of surfactant.

A surfactant, which performs well with carbon dioxide technology, would have to provide good nucleation, a high degree of emulsification, excellent froth stability, and good bulk stability. This paper reports on recent work to develop surfactants that possess all of these desired properties. Evaluations on commercial carbon dioxide machines have been performed and the results indicate these new surfactants provide improved foam properties compared to current surfactants. The improved foam properties include excellent fine cell structure, elimination of striations, improved airflow, and enhanced sidewall integrity. All of these properties are discussed in detail, along with several other benefits.

Proceedings of the Polyurethane Foam Association Technical Program 
May, 1999

S99001 Product Safety for High Production Volume Chemicals, A. H. Chapelle, PhD, ICI Polyurethanes

This paper describes the EPA Chemical Right-to -Know Initiative for High Production Volume (HPV) Chemicals. It provides a definition for HPV chemicals, the polyurethane chemicals covered by the definition, and how the industry plans to comply to the EPA rule. Included in the paper are the costs associated with conducting SIDS (Screening Information Data Set) tests, and the results of analysis conducted the CMA. The author stresses the benefits of voluntary commitments for testing, and provides guidelines for the volunteering process. The paper concludes with the EPA’s role in rule making, and an overview of the HPV chemical testing process.

S99003 New Pigment DispersionTechnology for Flexible Foam, R. M. Harris, PhD, Ferro Corp.

Using a systems approach, Ferro have developed new pigment dispersion technology for flexible foam. The technology is tailored for ether-based polyurethane foam, and makes use of advances in formulation and processing know-how to achieve carbon black dispersions with more than three times the jetness of current products. Direct comparison against current, more expensive, dye dispersions indicates the new carbon black pigment dispersions provide equal or better tinting strength at equal levels up to 3 PPH. Other added benefits are: 1.) The resulting dispersions have half the viscosity usually obtained with standard carbon black dispersions for flexible polyurethane foams, and 2.) the foam producer can blend the new pigment dispersion with available dye dispersions to obtain color value heretofore unachievable.

S99005 Fire Safety Assessment For Mattresses, T. J. Ohlemiller, NIST

Fires and fire deaths in which a bed was listed as the first item ignited persist as major contributors to the U. S. fire toll. Most of these fires still result from cigarette ignitions. These fires may produce heat and toxic gas release levels that pose a serious threat to occupants of the room and beyond.

Most beds comprise a mattress and a foundation surrounded by sheets, blankets, pillows, etc. The bed clothes are most often in direct contact with the small flame or cigarette, and they magnify the primary source of ignition. Since beds are a unique fire hazard problem, there is no methodology currently available for relating tests of the components to the fire performance of the assembly.

This paper describes the objectives of the NIST program. They hope to:

1.) Characterize the level of thermal insult imposed on mattresses when bed clothing is the first item ignited.

2.) Determine how well available, marketable mattress technologies resist burning bedding.

3.) Develop a real scale test method for measuring the fire hazard contribution of mattress/foundation sets

4.) Develop a bench-scale composite or component method that would serve as an accurate screen for the full-scale test.

In order to achieve these objectives, NIST plans to:

  1. A) Scope the range of burning behavior of bed clothes combinations
  2. B) Characterize the heat flux patterns imposed on a mattress/foundation by a range of bed clothes combinations
  3. C) Design simple gas burner(s) which simulate the local thermal insult imposed by bedding
  4. D) Assess the potential fire safety improvement attainable with current, marketable flammability modifications in mattresses.
  5. E) Provide data for use with a SPSC survey of bedding usage in various occupancies to estimate the probable real world impact of improved mattress designs.

The project was started in August of 1998, and the final report on level of improvement in fire behavior from beds using available, marketable mattress technologies is scheduled to be completed in February of 2000.

S99002 The Economics of Aging, How the Baby Boomers' Retirement will Restructure the Economy and Fundamental Public Policies, W. W. Beach, The Heritage Foundation

This paper begins by presenting an overview of population forecasts, dependency ratios for children and elderly populations and continues with investment habits, consumption of cars and medical services, off-premises food and clothing, household operation services, transportation services, durables, and household equipment and furniture as a percentage of GDP (1992). The author also forecasts manufacturing employment and service employment, and construction employment, as a percentage of total employment.

The author concludes that Americans are living much longer and as a result the number of Americans over seventy will double by 2030. An aging population means fewer workers to support each retiree’s benefits, and the Social Security “Surplus” will soon be a thing of the past. He also concludes that Americans are receiving Social Security and Medicare benefits for much longer periods of time.

S99004 Evaluation of CPSC Upholstered Furniture Flammability Test, K. A. Reimann, BASF Corp.

In the early 1990’s, a petition was submitted to the Consumer Product Safety Commission (CPSC) asking the agency to address flammability hazards associated with upholstered furniture. CPSC reviewed the petition and granted the portion dealing with hazards of small open flame ignition. CPSC developed a flammability fixture and test similar to the BS-5852 test. BASF used one of these fixtures to test more than 100 fabrics over four types of conventional and fire retarded (FR) polyurethane foams using the CPSC test protocol;. Many of the fabrics were also treated with flame retardants to improve performance in the test.

The results indicated that there was some pas/fail inconsistency with FR backcoated fabrics which passed the BS-5852 : 1990 small open flame test. Many of these fabrics did not pass the CPSC test, and of those that didn’t, there were mixed pass/ fail results in most. For cotton fabrics, a solution topical FR treatment was effective. Laminated interliners seem to be effective for poorly behaved fabrics.

Inconsistency in some test data and other technical issues raised during this evaluation indicate that the currently written CPSC protocol may not be appropriate for use as a national flammability standard for upholstered furniture. At a minimum, it is suggested that a rigorous round robin trial be undertaken to further assess the technical merits of the test protocol.

S99006 Evaluation of Fabric Effects in Various Open Flame and Cigarette Ignition Tests, H. Talley, J. Ziolkowski, The Hugh Talley CO.

This paper describes the results of studies conducted by the authors to determine the durability of fire retardant treatments on upholstery fabrics using the BS-5852 small open-flame test. They also studied the effects of Immersion Treatment/ Ammonia curing flame retardant treatment on cigarette ignition propensity of 100% cotton fabrics, and the effects of FR backcoating on the cigarette ignition propensity of 100% cotton fabrics.

Based on the results of this study, it was concluded that the BS-5852 and CPSC draft test method do not adequately predict full-scale fire performance of upholstered furniture due to the variability of the of the FR backcoatings and the test method itself.

The ignitability of upholstery fabrics can be adversely affected by cushion constructions as well as in-use durability and other conditions making the BS-5852 and the similar CPSC test unreliable for predicting full scale fire performance.

The use of FR backcoatings can result in commercially unacceptable upholstery fabrics.

FR backcoating of 100% cotton fabrics did not eliminate the problem with open flame ignitions nor did it resolve the problem with smoldering ignitions.

The test results and observations from this study make it clear that FR treatments on fabrics do not make them completely consistently resistant to small open flame ignition or to cigarette ignition.

Proceedings of the Polyurethane Foam Association Technical Program
October, 1998

F98001 Knife Type Blades For Cutting Flexible Polyurethane Foam,R. Winsell, Simmons Engineering Corp.

Advances in foam technology over the past few years have led to the development of many new types of foam. These include memory foam and the extremely high IFD, dense foams. Ultimately, these products must be formed into final shapes, typically using knife type blades or saw blades. Prior to the development of these new foam products, blade selection was very simple. It was either a knife blade or a serrated tooth blade.

Simmons Engineering specializes in the manufacture of blades for the industry. This paper was used to introduce new type foam cutting blades as well as to share information on the selection, application, and trouble shooting of blades for cutting foam.

The factors which affect blade selection, are foam density, firmness, IFD, compression force deflection etc. One or all of these factors can affect the cutting action of the blade, making selection of the proper blade somewhat difficult. This process can be simplified if only penetration and resistance are considered.

This paper describes the various types of available saw blades, and the best applications for their use. A Trouble Shooting guide is also included to assist the foam manufacturer in solving some of the most common foam cutting problems.

F98003 The Influence of Silicone Surfactants on Frothing using Dissolved Carbon Dioxide, D. V. Dounis and B. L. Hilker, Witco Corp.

Since the Montreal Protocol of 1987 banned the use of chlorofluorocarbons, the polyurethane industry has been scrambling for a viable substitute. Liquid carbon dioxide technology appears poised to become the leading candidate for auxiliary blowing agents, at least in flexible slabstock foam. Since this new technology poses specific requirements for urethane additives, the need has developed for greater understanding of these additives in this process. A method has been developed for the evaluation of the frothing characteristics of silicone surfactants using a process involving dissolved carbon dioxide. First, a predetermined amount of carbon dioxide gas is dissolved in a surfactant/polyol non- reactive blend using high pressure. After equilibration, froth is generated as the mixture flows through a pressure let- down nozzle giving it the same appearance as the froth in liquid carbon dioxide-blown foams. This froth is then evaluated under a microscope where the bubble size distribution and bubble stability are measured as a function of time. The bubble stability or decay was observed to follow first order kinetics from which a decay constant was calculated and compared for different silicone surfactants. The silicone surfactant had a large impact on the decay constant as well as the bubble size distribution. This was attributed to effective absorption of the surfactant onto a bubble surface influencing stabilization of the instantaneously nucleated bubbles in liquid-carbon dioxide technology foaming. This technique has demonstrated the ability to differentiate surfactants for use in this new technology.

F98005 The Green Conflict in Detroit and Europe, and How it Effects Your Business, D. Schomer, PURRC

This paper discusses the “End Of Life Directive” relating to the recovery and recycling of polyurethane foam from automobiles. It presents an overview of the North American programs, The European Directive, and the Impact on the scrap foam markets. The main points of this legislation are as follows: 1.) The proposed legislation would limit energy recovery to five weight percent until 2005 and 10 percent after 2015. 2.) It implements the principal that the car producer is responsible for collection and recovery. 3.) It allows the collection of recycling fees.

 The impact of this legislation on the polyurethane foam industry is significant. It would require targeting seat foam to reuse. Experience shows that 14 lbs./car can be recovered. At a production rate of 10 million cars each generating 14 pounds of foam scrap foam per car, there would be 140 MM pounds of foam generated. This volume will depress foam prices. This increase in scrap foam production will reduce the virgin polyurethane foam markets unless it is managed.

In conclusion, there is a need to develop new applications for scrap foam.

F98007 Formcalc© Formulation Calculator- 'A Predictive & Analyzing - Formulator's Tool', R. J. Lockwood, ICI Polyurethanes

The calculation of stoichiometric quantities of materials for a polyurethane system has always been a requirement, and calculation spreadsheets or programs have been devised by many suppliers and manufacturers. Since calculation spreadsheets or macros are so easy to create with today’s software, it is easy to devise a comprehensive calculation program that covers both routine formulation stoichiometry and many other polymer- physics parameters. These programs provide a more in-depth analysis of a polyurethane formulation. Formcalc© is such a calculation program that has been devised and used over about ten years with numerous revisions and refinements along the way. It has brought great insight and value to formulating experts over this period. The purpose odf this paper is to share the approach and value that Formcalc© can bring to the common polyurethane formulator, whether in the development laboratory or the commercial manufacturing environment.

F98009 Development of Superior Comfort Flexible Foams for High Quality Furnishing Applications, C. Banner and B. Bastin, Shell Research , S.A.

The major applications of flexible slabstock polyurethane foams are in bedding and upholstered furniture. As comfort is an important factor influencing the quality of furnishing materials, development work at Shell Chemicals has focused on the improvement of flexible polyurethane foam comfort to provide superior customer value. Conventional methods used by the industry to assess foam quality are based on the quantitation of foam mechanical properties. Although important in assessing, amongst others, durability of foam product, many of these fail to describe what is essential to comfort, the interaction of the foam with the human body. Therefore Shell Chemicals developed a number of new approaches to assess the comfort properties of foam. These approaches include the measurement of foam comfort and support factors, foam feeling analysis and foam moisture uptake and release measurement.

On the basis of these studies, a polyol composition and foam formulations were defined that offered comfort properties superior to those of normal high resilience foams. This technology is termed CARATech. In assessment of the end product performance of CARATech foams, a mattress pressure sensor system confirmed the superior sleeping comfort provided by this material. While having the clear advantage of superior comfort over high resilience foams, CARATech foams were demonstrated to have similar durability. In addition, stable processing of CARATech foam is achieved on high resilience-equipped industrial foaming machinery, without need for special isocyanates or other additives.

F98011 Overview on the Combustibility and Testing of Filling Materials and Fabrics for Upholstered Furniture, L. Peters, PFA

Almost from the beginning, it has been recognized that flexible polyurethane foams (FPF) can be ignited and, depending on conditions can burn vigorously. This is an inherent property of materials of this type. The polymer is an organic material, and any product based on carbon will burn. In the case of flexible polyurethane foam this tendency is increased by the fact that foam has a very large surface area per unit weight and being opened celled allows ready access to the oxygen (air) required for combustion.

As indicated in the title, this paper presents an overview of the testing which has been conducted to assess the flammability of flexible polyurethane foams. It begins by presenting a brief history of the early attempts to measure the performance of FPF when ignited by small ignition sources, and continues with some of the variables involved with the ignition and burning performance of a piece of upholstered furniture. Next, the various types of flammability tests, which have been conducted on furniture components and composites and automotive seating, are discussed. These include both small scale and large scale testing, open flame and smoldering tests. The factors affecting test performance such as material interactions, and interactions of combinations along with the variables of ignition and flame spread are also discussed. Lastly some of the available combustion modifying additives are discussed. These include halogen and phosphorous compounds, other additives, alternate processes and fabric treatments.

The author then summarizes the flammability testing, regulatory concerns, test criteria, test procedure requirements, and other technology requirements.

F98002 The European Scenery: Overview of Europur Research Activities, Dr. Hubert Creyf, Europur/Recticel

The aim of this presentation is to familiarize PFA members with recent activities in the European field of polyurethanes. Europur’s reaction to the events is also highlighted.

The main and most general feature which influences the mind of Europur’s customers, is the phenomenon of “Chemophobia”. In response to the situation, Europur has started an exercise, similar to a previous US one. The scope, however, is somewhat larger. End-products which may influence the customer via air (volatiles) or via body contact through migration, will be subjected to a risk evaluation. Besides foams, fabricated products such as mattresses, furniture and laminates used in the car industry are also included. Special emphasis will be laid on products, which will be responsible for odor.

A study on migration with sweat has been included, because in Europe, many questions on the presence of “extractables” are raised.

Standard Operating Procedures for analysis of volatiles and migration products from foams have been developed. First trials with entire mattresses and laminates are just finished.

TDI and MDI will also be reclassified. The main change anticipated is that TDI will change from “toxic” to “very toxic class 3 carcinogen”. For MDI an unimportant change is foreseen (sensitizing through skin contact), however, new elements for MDI may possibly be introduced by the German delegation in the future. It is rather difficult to correctly estimate the consequences of this reclasssification.

Life cycle analysis (LCA) data of different materials is also a new, and growing in importance. Europur has, based on the ISOPA calculations of LCAdata for polyols and isocyanates, extended the calculation to flexible polyurethane foam and trimfoam.

Fire Legislation, over the past two years, has been relatively quiet. The European Union does not feel the need for further legislation at this time. The French government may further consider the national directive, which regulates the ignitability of furniture and bedding. Italy is preparing some voluntary legislation in the mattress area. Europur is conducting experiments, at the Fire Research Station (UK), testing the toxicity of the fire gases of upholstered furniture under vitiated conditions. The aim is to develop a small- scale tube test, which would predict the toxicity of gases. So far, the results of large- scale testing, indicates there were no isocyanate vapors detected.

In other fire related testing, the toxicity of extinguishing waters, is being studied. Results from real scale study on standard foam indicated that no containment is necessary. The toxicity of extinguishing waters from FR foams was much more difficult to judge. It was decided that the ISOPA and Europur experts, together with the University of Wuppertal, conduct some more lab tests , and ask expert advice.

The effect of the Emission of VOC Directive on the activities of the PU foam producers was studied by III. The main conclusion was that foam manufacturers would have no problems meeting the legislation, provided they abandon the use of auxiliary blowing agents. The use of active carbon filters, to get rid of TDI vapors, may be necessary in some countries. The fate of ternary amines is also being examined in the same study.

Recycling of PU foam is expected to become an important issue in the near future. An organization called Euromolders was created to determine how best to increase the percentages of recycled foam from molded PU seats.

The author concludes that Europur is preparing itself for the challenges of the future.

F98004 Optimizing the Design of Silicone Surfactants for Slabstock FPF Blown with Liquid Carbon Dioxide, R. Borgogelli, R. Thomas, Dr. Andreas Weier, Goldschmidt Chemical Corp.

The use of liquid carbon dioxide as a physical blowing agent for the production of slabstock flexible polyurethane foam (FPF) has been demonstrated commercially for several years. It is a viable alternative for the complete elimination of chlorofluorocarbons (CFCs) and regulated volatile organic compounds (VOCs) from foam formulations. This achievement has been realized only through the cooperative efforts of foam line crews persevering through the challenges of start -up, and providing valuable feedback to equipment manufacturers and chemical suppliers in their quest to optimize the process.

This paper presents an overview of the fundamental requirements for the successful use of liquid carbon dioxide as a blowing agent in foam production. It also discusses: The Role of a Silicone Surfactant, Trends in Surfactant Design, Optimizing Nucleation, Achieving Consistent Cell Structure, Optimizing “Universal” Surfactants, Optimizing FR Performance, Optimizing Processing Latitude, and Optimizing Foam Stabilization.

The performance profiles of the current commercial surfactants recommended for liquid carbon dioxide blown foams are presented along with their benefits. Although the liquid carbon dioxide process provides foam manufacturers with a viable option for addressing the increasing regulations on blowing agents, the sensitivity of this process is still very high. The challenge for the future is to continually explore ways to make the process more robust and foam quality more consistent.

F98006 Optional Adhesive Choices, B. Hazelgrove, Imperial Adhesives

This paper presents an overview of the different types of adhesives available for use in fabricating polyurethane foams. The advantages, disadvantages and types of application for water borne, hot melt, flammables, and N-propyl Bromide are discussed.

F98008 Low Odor Amine Catalysts For Flexible Foams, E.L. Rister, Jr., F. Kohoutec, Dr. R. Grigsby, Jr.

The polyurethane industry continually faces new issues that effect changes in production methods. Recently, changes in blowing agents have been addressed with the development of new foam processes. Discoloration of fibers has been addressed with new raw materials. Odors, irritants, government regulations and industrial hygiene are also important topics of discussion at industry meetings. It is increasingly important to support improved safety and responsible care in all phases of the polyurethane market.

Tertiary amines are an essential ingredient in any flexible slabstock foam formulation. The foaming process parameters have been changed in recent years with the addition of new types of equipment. The amine concentration has been increased substantially and the amine choices changed to reflect higher specificity for the blowing reaction to control the initial viscosity with some equipment. The decision to use a particular catalyst in foam production considers the process, yields, durability and cost of the final products. A variety of other factors are also considered when choosing amines used in production. Some of these factors are: Health and Safety, Emission control, Public regulation, Odor reduction during production and storage, Changes in production methods, Odor reduction of the final product, Fogging reduction, Disposal and recycling, Extractables, and Toxicity.

While current catalysts are acceptable for this process, they do not address the long term objective of a more environmentally friendly, lower odor, less toxic catalyst system. Huntsman has developed several low odor catalyst systems for the different types of equipment available to foam producers. A variety of laboratory tests were employed to satisfy specific objectives during the foaming process. A low cost method for determining the time to the maximum rate of the water-isocyanate reaction was studied. Catalysts with a high specificity for the isocyanate-water reaction proved to be the best choices. The use of reactive catalysts with low vapor pressure is an acceptable method of reducing odor and worker exposure during the foaming process.

F98010 The Use of an Electronic Nose in the Detection of Odors in FPF's and Their Raw Materials, S. A. Kennerly, AromaScan plc.

Many companies use human sensory panels to assess the aroma of their products. The human nose is extremely sensitive to certain volatile chemicals. In some cases very low levels of compounds are detected e.g. 0.0005 ppm of hydrogen sulfide. In a mixed group there will be varying abilities to assess odors objectively. Some people experience a condition known as adaptation caused by the environment in which they work. This condition causes no chemoreceptive response within that individual, and will be effectively “smell blind” to certain compounds. This condition is often found amongst workers in chemical processing environments. Physical and emotional factors can also affect an individual’s perception of smell. To select and train a suitable group can be a time consuming and costly process.

The AromaScan® detector system is an array of 32 organic conducting polymers. They are based on heterocyclic molecules such as derivatives of polypyrole and polythiophene. The polymers have unique adsorptive surfaces that interact with adsorbed volatile chemicals based on their shape and size. The polymers display reversible changes in electrical resistance when polar volatiles adsorb and desorb. Each polymer in the array has a range of selectivity to different chemical species. Thus, the array exhibits a broad band response to many thousands of chemical species.

The response of each of the 32 sensors is measured and combined into a unique aroma “fingerprint”. Fingerprints of new samples can be compared with previously stored data.

The objective of the experiments described in this paper is to identify if this electronic nose is capable of discriminating the odors found in polyols and flame retardants which can give rise to unacceptable levels of odor in flexible foam.

The conclusions drawn from the AromaScan® Multisampler-SP are that it is a useful tool in determining odor differences between flame retardants and polyols in polyurethane matrices. The measured differences can be used as an odor specification to ensure the quality of supply of these products.

Proceedings of the Polyurethane Foam Association Technical Program
May, 1998

S98001 Measuring Emissions from FPF Plants in the USA, Karroll Booth, Bayer Corporation

This paper discusses the validation of two Industrial Hygiene methods for measuring TDI emissions from process stacks; presents examples of TDI emissions from slabstock foam lines; and provides a summary of recent state regulatory activities related to TDI.

Traditional industrial hygiene sampling procedures had not been validated to establish their suitability for the qualification of TDI emissions from polyurethane foam manufacturing processes. Recently, two methods (OSHA Method 18 and HSE Method MDHS 25/2) were subjected to a validation protocol developed by the United States Environmental Protection Agency (EPA). This protocol, known as EPA Method 301 (Field Validation of Pollutant Measurement Methods of Various Waste Media), establishes procedures for systematically evaluating the precision and bias of pollutant measurement methodologies.

OSHA Method 18 and HSE MDHS 23/2 meet the requirements of EPA Method 301 with respect to bias and precision.

S98003 Controlling TDI Emissions from FPF Plants, Steve Butterworth, Calgon Carbon Corporation

This paper addresses TDI emissions control techniques. The traditional methods for meeting emission limits from urethane foaming facilities include water scrubbers, incineration, raising the exhaust stack height, and deep bed activated carbon systems.

Although these control options have all been shown to be effective for emissions control, discussions with various foam producers and TDI manufacturers reveal a need for a more cost effective control methodology. Activated carbon is presented as providing a good combination of flexibility and removal efficiency for TDI control.

Specific techniques are described for using activated carbon for TDI emissions control, highlighting the benefits and performance of certain systems.

S98005 TDI Regulations in the USA, Jim McIntyre, McIntyre Law Firm

Toluene Diisocyanate (“TDI”) is regulated by the federal government and by most state governments. Because of the complexity of the federal regulatory framework, and because state regulation sometimes plays more of a backup role, this paper principally focuses on federal regulation.

The paper discusses how the federal government regulates TDI under the Clean Air Act, the development of emergency response plans related to accidental releases of TDI, and the conducting of public meetings pertaining to emergency response planning and notification under the Emergency Planning and Community Right-To-Know Act. Several federal statutes regarding shipment and disposal of TDI are presented. TDI disposal rarely applies for flexible polyurethane foam manufacturers, as essentially all TDI is consumed in the manufacturing process. Occupational Safety and Health Administration (OSHA), which regulated workplace exposure limits, is discussed with emphasis on TDI regulation in North Carolina.

This paper is intended as a general summary of laws and regulations pertaining to TDI. It is not intended as legal advice and should not be used as such. Because laws and regulations are subject to change, readers should consult legal counsel before making any decisions that might be affected by TDI regulation.

S98007 United Nation's Support Program for CFC Phase-out in FPF - Case Study for Liquid Carbon Dioxide, Bert Veenendaal, RAPPA Inc.

When Chlorofluorocarbons (CFCs) were determined to be ozone-depleting substances (OCDs), the Montreal Protocol was adopted in 1987. This international agreement was ratified by more than 150 countries as of 1996, and it specifies OCDs and time frames to restrict or eliminate their use. The Multilateral Fund (MLF) was subsequently developed to assist developing countries in complying with the Protocol through the financing of projects that dealt with evolving to the new standard.

CFC phase-out in the foam sector is an important part of MLF’s effort. Keeping appraised on new technologies, their costs, benefits, and possible application in MLF sponsored projects is part of its task.

In this light, the Fund decided to prepare a methodology to calculate the costs of flexible foam projects – slabstock (FPF) and molded (FMF) – using liquid carbon dioxide (LCD) as a blowing agent. This paper outlines the Terms of Reference for this task, including: Review of Technology, Criteria of Eligibility under Fund Policy, Capital Costs, Operational Costs/Savings, Sample Calculations, and Recommendations.

S98009 Furniture Performance Testing @ Consumers Union, Pat Slaven, Consumers Union

The Consumers Union has been actively testing products for more than 60 years. Large-scale performance of systems is examined, down to the nuts and bolts. The Union focuses on whether the advertised intended use of a product is appropriate, whether the product is durable and safe, as well as its performance after misuse.

This paper describes performance evaluation studies applied to reclining chairs, particularly the seating system. The Union purchased three samples of each of thirteen popular recliner models, and then evaluated the chairs for problems and damage after each testing session. The report describes the performance test methodology, provides test results and discusses the implications of the test outcomes.

S98002 The European Experience on TDI Emissions Control, John Chapman, Gilbert International Limited,

Historically, expenditures on emission control equipment and on costly process technologies have been driven largely by regulatory demands or by incidents which may have endangered people or the environment.

Scrubber systems were developed in flexible foam slabstock line stacks to meet more demanding emissions levels. The first scrubbers were aqueous and the industry evolved into use of activated carbon systems. Industry experts and regulatory authorities continue to push for better technologies.

Scrubber units capable of removing TDI from the effluent gases from FPF slabstock plant stacks are well proven. As far as anticipating future requirements, European foamers are focused on VOC issues, and the toxicological properties of t-amines are being monitored.

 

S98004 TDI Antibodies, Pat Conner, BASF Corporation

Determination of diisocyanate hypersensitivity causes much concern and often confusion. Antibody tests and methacholine challenge tests have been used but do not provide clear-cut information.

Studies of antibodies in serum conjugates of a diisocyanate have also been inconclusive as a method to determine allergic reaction to the compound. A positive reaction found using this method may only be an indicator of past exposure.

Methacholine challenge tests determine non-specific bronchial hyperactivity. Greater pulmonary sensitivity to this pharmaceutical upon inhalation is seen in cases of diisocyanate hypersensitivity. However, many other factors impact an individual’s responsiveness to this drug. Sensitivity to the methacholine varies over time. Interpretation of methacholine challenge tests is complicated and demands knowledge of the limitations of the test. Even though its use is recommended by some notable experts, in practice, it is difficult to obtain sufficiently reliable information to act upon from this test.

S98006 Beneficial Effects of Cushion on Carpet Appearance Retention and Longevity, Bill Wald, Carpet Cushion Council

Most people agree that carpet cushion provides comfort and luxury. In contract applications, when cushion is installed beneath the carpet, there is concern about carpet delamination, wrinkling, restretch, and cost. The carpet industry is inclined to promote the traditional direct glue down carpet system, designing products accordingly. Specifier and end-user education is needed within the contract marketplace to correct misconceptions.

Studies were conducted to evaluate delamination and restretch potential for three groups of contract carpet cushion (fiber, rubber, and polyurethane). Thirty-two cushion samples were analyzed to determine compliance with industry specifications.

The results of various performance tests are described, including the PFA Walk On Test and the Hexapod Drum Test. Based on these tests, a solid case can be made for using any suitable commercial cushion in extending carpet life in commercial carpet applications.

S98008 CPSC Activities - Upholstered Furniture Flammability, Dale Ray, Consumer Products Safety Commission

In this presentation, CPSC upholstered furniture flammability activities are summarized. An overview of upholstered furniture fire hazards is followed by the more recent CPSC activities, such as the NASFM Petition, standards development, performance/conformance evaluation, and the commission vote.

Statistics concerning fire loss estimates for the upholstered furniture industry, including deaths, were displayed. There is a need for more intensive investigations to support a better understanding of upholstered fire flammability and its potential risks. The causes, effects, and related damages of upholstery fires are described and supported by statistics.

Methods to lessen the upholstered furniture flammability risk and toxicity issues possibly related to some flame retardant chemicals are discussed. The economics vs. performance benefits of these chemicals are compared using flammability tests. The goal is to bring about a reasonable, technologically practical, and objective Flammability Standard.

S98010 Fundamentals of FPF Slabstock Catalysis, Mark L. Listemann, Air Products

Formation of flexible slabstock polyurethane foam is a complicated process involving multiple simultaneous reactions, rapid volume and temperature increases, and the ultimate development of a phase separated polymer network. The kinetics of the foaming process, temperature and viscosity profiles, and morphology development have all been studied in great detail using numerous techniques. However, no technique can provide a complete description of the sequence of events necessary to produce acceptable foam. In this paper, foam model studies, infrared spectroscopy, and the mass-loss / rate-of-rise technique provide a more detailed description of the role of the industry standard catalysts in the foaming process.

Proceedings of the Polyurethane Foam Association Technical Program
October, 1997

F97001 MDI Adhesive Selection and Production for Bonded Flexible Foam Trent A. Shidaker, Robert J. Lockwood, Brain Fogg, ICI Polyurethanes

Manufacturing urethane adhesive at a bonded foam production facility offers product reproductibility, cost saving, and unlimited flexibility in formulating. Bonded foam facilities should fully exploit the advantages of their current adhesive system by working closely with their polyurethane supplier in determining the optimum adhesive cooking time for their specific plant conditions.

The date shown in this paper indicates a strong correlation between adhesive conversion and physical properties. Three different isocyanates in bonded foam adhesives are investigated: Rubinate 9041 (R) (i.e., an MDI engineered for bonded Foam), PMDI, and TDI. Maximum conversion is desirable for the Rubinate 9041 adhesive to maximize tear resistance, tensile strength, elongation, compression set, and firmness. Compression set worsens with increasing conversion for PMDI adhesive due to the higher isocyanate functionality. TDI adhesives require at least 35% conversion, the TDI adhesive does not bond foam crumb due to adhesive absorption in the foam crumb, rendering the bulk of the adhesive ineffective. Two models, based on chemical engineering fundamentals, are presented to calculate adhesive temperature and conversion for specific plant conditions.

F97003 Hazards Associated with the Storage of Flexible Polyurethane Foam in Warehouse Situation, Joe Hankins, Factory Mutual Research

The hazards associated with the bulk storage of polyurethane foam, either at foam manufacturing facilities or furniture manufacturing facilities, are discussed in this paper. The factors which have the most impact on large scale fire performance are also discussed. The Factory Mutual system is a group of insurance companies who insure industrial properties and make recommendations for protecting manufacturing facilities and minimizing risk of serious fire.

One of the fundamental properties of a material is the amount of heat it generates when burned. Wood, paper and cotton generate 6-8,000 BTU’s per pound. Plastics, polyurethane and other organic materials generate 16-20,000 BTU’s per pound. A pound of polyurethane will give off three times the heat of a pound of paper or wood.

The other property that affects fire performance is the burning rate. Burning rate is a function of the physical state of a product, i.e., whether it is expanded, as in a foam, or not. The lower the density of a product, the faster it burns. A product that melts generally produces a much more severe fire than one that chars. Flexible foam typically melts while rigid foam chars.

The heat content and the burning rate in combination produce the heat release rate of the product. This property defines the challenge that the sprinkler system is going to have to control the fire and cool the building and keep if from collapsing.

Fire retardants and flame barriers have a significant impact on the ignition characteristics of the foam, however, once the material starts to burn, the fire retardants have a much more limited effect. Fire retardants do not have any effect on the heat content of the foam, which is still about 18,000 BTU’s for polyurethane.

Fire hazards can be minimized by working with the insurance carriers to first understand the problems, and then developing the engineering standards to guard against them.

F97005 MDI Adhesive Selection and Production for Bonded Flexible Foam Trent A. Shidaker, Robert J. Lockwood, Brain Fogg, ICI Polyurethanes

Manufacturing urethane adhesive at a bonded foam production facility offers product reproductibility, cost saving, and unlimited flexibility in formulating. Bonded foam facilities should fully exploit the advantages of their current adhesive system by working closely with their polyurethane supplier in determining the optimum adhesive cooking time for their specific plant conditions.

The date shown in this paper indicates a strong correlation between adhesive conversion and physical properties. Three different isocyanates in bonded foam adhesives are investigated: Rubinate 9041 (R) (i.e., an MDI engineered for bonded Foam), PMDI, and TDI. Maximum conversion is desirable for the Rubinate 9041 adhesive to maximize tear resistance, tensile strength, elongation, compression set, and firmness. Compression set worsens with increasing conversion for PMDI adhesive due to the higher isocyanate functionality. TDI adhesives require at least 35% conversion, the TDI adhesive does not bond foam crumb due to adhesive absorption in the foam crumb, rendering the bulk of the adhesive ineffective. Two models, based on chemical engineering fundamentals, are presented to calculate adhesive temperature and conversion for specific plant conditions.

F97007 A Shift in A-O Packages: Aromatic Amines As the Primary Heat Stabilizers for Flexible Polyurethane Foam, R. A. Calabrese, D. B. Parrish and R. A. Boccuzzi, Uniroyal Chemical Co., Inc.

Recent concerns over the use of butylated hydroxytoluene (BHT) as a heat stabilizer for flexible polyurethane foam have resulted in the use of higher molecular weight, and higher cost, phenolic antioxidants as replacements. The change was prompted by concerns over the volatility of BHT, which can result in its being emitted into the environment during the foaming process. It can also slowly migrate from polyurethane foam cushions, carpet pad, or clothing padding and allegedly cause discoloration of carpets, clothing and drapery materials. These more costly alternatives are not as efficient as BHT.

This paper summarizes development work at Uniroyal Chemical Company in which the traditional ratio of high phenolic to low amine has been re-examined by way of statistically designed experiments. Laboratory flexible foams prepared from polyols containing various antioxidants are compared under thermally stressed conditions by microwave heating the freshly produced foam. Discrimination among the various antioxidant packages is determined by statistical evaluation of the color developed due to this thermal stress.

Analysis of the designed experiments has shown a number of highly effective combinations in which hindered aromatic amines comprise a larger portion of the total antioxidant package. These high amine/low phenolic antioxidant packages have the potential to give exceptional performance and markedly reduced emissions. This is done at reduced cost versus formulations, which use higher molecular weight phenolics as the primary antioxidant.

F97009 Lessons Learned on the Road to a Zero Risk Environment Patrick J. Coughlin, Operation Life Safety

 

This paper is an update on Operation Life Safety. Operation Life Safety was formed in 1983 to educate the fire service about the value of fire sprinklers. If residential fire sprinklers are installed along with smoke alarms, the probability of surviving a fire is over 90 percent better than in a home without them. Smoke alarms alone increase the probability of survival by only 47 percent. Although developed as a life safety tool, residential sprinklers also proved to significantly reduce property loss.

Patrick Coughlin presents a Fire Risk Equation, which is made up of three parts. They are:

  • The probability of a fire starting
  • The probability that the fire will grow beyond its container
  • The probability that the fire will damage property, or injure or kill

Each of the three probabilities has a primary mitigation method, which is the most effective of the three mitigation methods of education, code enforcement, and suppression. These are discussed by the author.

F97011 Efficiencies of Various Formulations of Decontamination Solutions Utilizing Toluene Diisocyanate, Kathy Kiestler, ARCO Chemical Co.

Traditionally, a combination of solid sorbents and liquid decontamination solutions has been utilized for toluene diisocyanate (TDI) spill remediation. The objective of this study was to focus on the liquid decontamination solution, and to specifically compare the efficiencies of various commercial and in-house formulations. To-date no such comparisons have been published. TDI reacts slowly with water to form ureas and carbon dioxide gas. Historically, users have sought to hasten the reaction by adding surfactants and alcohol to disperse the TDI, and ammonia to catalyze the reaction.

 A variety of decontamination solutions were chosen for testing. Recommendations were solicited from the Analytical Subcommittee members of the International Isocyanate Institute. A commercial preparation was also tested in addition to decontamination solutions endorsed by the Polyurethane Division of the Society of the Plastics Industry, Inc.

 

Three of the formulations tested outperformed the others with respect to vapor suppression and reactivity. This experiment was undertaken to minimize the risk to personnel during TDI spill clean-up. Although all the solutions would have eventually reacted completely, faster decontamination is certainly more desirable. Regardless of where TDI spills occur, it is important that people are not exposed to TDI vapor. Although some solutions seemed to be quite active as evidenced by CO-2 bubbles and urea formation, their performance could not be judged by visual activity alone. The use of instrumentation to detect isocyanate concentrations in air directly above the spill is very important, given that others have suggested that isocyanate sensitivity may be the result of single high exposures.

F97002 How a Furniture Manufacturer Complies with TB-133 Requirements Peter Barile, Shelby Williams

In 1984, the state of California first published a new flammability standard for public seating entitled Technical Bulletin 133. It was revised in 1988 and 1990. TB-133 differed in several ways from flammability standards then in use such as TB-117 and NFPA-701, UFAC or FAA 25.853.

First, TB-133 is not a component standard. It tests an entire chair or full size mockup. Second, TB-133 measures up to seven separate criteria simultaneously, not just one or two as in small scale tests. Failure in any one of these categories constitutes a test failure in TB-133.

Finally, TB-133 differs from most small scale tests in that the heat source is a ring of fire made up of 33 separate gas fed flames applied to the seat/back area of the test chair for 80 seconds.

The complexity of TB-133 still creates much confusion among people it affects including: interior designers, chair manufacturers, component suppliers, property owners and even some fire officials.

Shelby’s testing program resulted in two classifications and a rating system for predicting TB-133 outcomes without actual testing. Upholstery fabrics are rated from 1 (lowest risk) to 7 (quite flammable). The geometry of the chairs is also rated and extends from 1 through 5. The lowest represents a simple chair with only a small upholstered seat and back separated by about four inches or more. The rating 5 is for a fully upholstered lounge chair of sofa.

 

Their testing has shown that you can successfully use a high risk fabric on a low risk chair and vice versa. After extensive experience, it was determined that you can add the fabric rating to the style rating and if this sum is 7 or less, the final production chair can be expected to meet TB-133 criteria. The rating system is, however, based on the use of a flame retardant foam and a barrier.

 

Testing by Shelby and others has shown that a flame retardant barrier between fabric and foam is effective, and in many cases essential to passing TB-133. The Crib 5 foam with an active barrier continues to be the most effective choice in conjunction with the Shelby risk rating system.

F97004 NovaFlex (TM) the New Frontier R. L. Kirschner, J. S. Pisipati, Bayer Corp., K. V. Lamb, Hennecke GmbH

The Novaflex (TM) liquid carbon dioxide blowing agent process has proven itself highly successful in the slabstock industry. NovaFlex was developed by Hennecke GmbH, a member of the global Bayer Group.

This process has demonstrated its high quality, reliability, and cost effectiveness. A wide variety of foam grades that were previously being produced with high levels of methylene chloride, can now be formulated with liquid carbon dioxide as the auxiliary blowing agent. Slabstock foam manufacturers can now produce high quality products under the newest plant safety and environmental regulations.

Bayer and Hennecke have started up more than 15 plants using the NovaFlex process in Europe and North America over the last three years. As a result, they now have the experience and the know-how needed to further advance this technology.

This paper describes some of the extensive experience and information that was developed from starting up and optimizing many different production operations. The current focus of ongoing research and development activities is also discussed.

F97006 A Modern Approach to Classical Reaction Studies of Tertiary Amine Catalysts in Flexible Polyurethane Foam E. L. Rister, Jr., F. Kohutek, Dr. R. A. Grigsby, Dr. R. Zimmerman, Huntsman Chemical

The water-isocyanate, hydroxyl-isocyanate and numerous crosslinking and side reactions that occur in the production of flexible urethane foam are extremely important. These reactions are usually investigated with emphasis upon reaction kinetics in a solvent. While these data are useful, they do not give an accurate account of the reactions taking place in flexible foam manufacture.

The reactants are not the same, nor are they present in realistic concentrations. A combination of model reaction studies, ultrasonic rate of rise, weight loss, FTIR, and mocrodielectrometry was used to study the activity of specific amines in flexible foams of various density and hardness. The activities are shown both in parts by weight and millimoles catalyst per reactive unit. Log ion viscosity was used as a measure to show the total cure per millimole catalyst. FTIR gives a real time account of the many reactions that occur from initiation to final cure.

The disappearance of hydroxyl and isocyanate groups was measured by titration with di-n-butylamine and by direct measurement with FTIR to establish Gel/Blow values of specific catalysts. Factors such as vapor pressure, amine value, spacing of active centers, molecular weight, Gel/Blow ratio, and end group analysis were considered to optimize catalysts for particular types of foam. Comparisons of hydroxyl contain tertiary amines with those containing no hydroxyl termination are compared in low density flexible foams. The authors show that due to the complexity of foam production, different amine choices are needed for specific applications.

F97008 The Impact of Chain Extenders and Crosslinkers on the Polymer Morphology of Slabstock and High Resilience Foam Elastomers B. Davis, L. Latham, G. Barnes, The Dow Chemical Co.

Typically chain extenders of crosslinkers are not used in polyurethane slabstock foam formulations because they tend to narrow the catalyst processing latitude to an unacceptable level for large scale production. On the other hand, diethanolamine is the crosslinker of choice for molded high resilience foams. Some of its desirable performance parameters depend on this additive.

The morphological changes induced by the incorporation of crosslinkers such as DEOA, TEOA, glycerine, or MEG as chain extenders in both slabstock and molded high resilience foam elastomer have been elucidated by the use of FTIR, DSC, DMS, SAXS. It is shown that the crosslinkers have a dramatic effect on the hard phase organization and its distribution in the soft phase. In some cases the stiffness of the polymer increases, and in others it goes through a minimum.

F97010 Determination of the Extracability of TDI from Polyurethane Foam into Air J. M. Hugo, M. W. Spence, T. D. Lickly, The Dow Chemical Company

This study was conducted to determine if toluene diisocanate (TDI) could be extracted from polyurethane foam into air, at the earliest possible time point at which a customer could obtain the foam from a polyurethane foam producer (three days post production).

 The study was divided into two phases. In Phase 1, four foam samples, each produced by a different manufacturer, were prepared at high index-high density, high index-low density, low index-high density and low index-low density. The foam samples were cut to the appropriate size, sealed in Tedlar® bags, and shipped to Dow Chemical for testing. On the third day after production, each foam sample was placed into the glass test chamber and extracted using 37 degree Centigrade, 30% relative humidity (RH) air. The air was pulled through the test chamber at a flow rate of 1.0 L/min. Using a calibrated sampling pump.

 In Phase 2, two of the four samples (high index-high density, and low index-low density) were “loaded” with TDI at a concentration of approximately 10 ppm. (w/w) in the foam. The samples were “aged” for three days prior to being placed in the test chamber and extracted for a three day period. The foam samples were extracted using 37 degree Centigrade, 30% relative humidity (RH) air. The air was pulled through the test chamber at a flow rate of 1.0 L/min. Using a calibrated sampling pump.

Analysis for the filter samples from the four Phase 1 foam extraction tests showed no detectable TDI with a detection limit of) .3 micro grams TDI/5ml acetonitrile (3X background) or approximately 0.12ppb in air based on an 8 hour sampling time, 1LPM showed no TDI at a concentration of 1.2 micro grams / rinse.

The Phase 2 testing indicated that:

  • Polyurethane foams could be loaded with TDI to a level of approximately 1.0 ppm (w/w) by passing air containing 50-75 ppb (v/v) TDI through them. Removal efficiency of TDI from the air stream by the foam was greater than 99.9%.
  • No detectable TDI could be extracted into air passing through polyurethane foam samples, which had been loaded with TDI to a level of approximately 1.0 ppm (w/w). The quantitation limit for TDI in the extraction air was 0.12 micro grams (0.04 and 0.02% of the theoretical load for the low and high density foams, respectively).

Proceedings of the Polyurethane Foam Association Technical Program
May, 1997

S97001 Crisis Management, Bob Luedeka, Barbara Weathers, J. P. Hogan

The objective of this presentation is to present a how-to guide to managing business-threatening events.

Information is provided to:

  1. Help establish a crisis communication policy and initiate a program
  2. Help in the evaluation of an existing program Provide do-it-yourself tools for the adventurous
  3. Help prevent damage
S97003 New, Low Fugitively Amine Catalyst for Use in Polyurethane Foam K. Kaye Robinson and Richard M. Gerken, Witco/OSI

Due to environmental concerns regarding volatile amine catalysts in the polyurethane foam industry, new product development research has centered on identifying non-fugitive (i.e. nonvolatile or reactive) products that still maintain reasonable catalytic activity. A number of reactive tertiary amines containing hydroxyl or primary/secondary amine groups have been developed as potential low fugitivity catalysts. In addition, other amine compounds have been investigated as having lower fugitivity due to their high molecular weight and low vapor pressure.

NIAX Experimental Catalyst UAX-1094 is one of these new compounds. This new catalyst achieves lower fugitivity primarily through high molecular weight and low vapor pressure, but also has the potential to reach into the foam matrix. UAX-1094 also shows reasonable catalytic activity in a number of different foam applications.

Discussed in this paper are the evaluations of UAX-1094 in several different types of polyurethane systems, with a particular focus on utility in polyester foams. The relative catalytic activity of UAX-1094 is compared to the catalytic activity of industry standard catalysts such as NIAX Catalyst A-1, NIAX Catalyst A-33, N-ethylmorpholine (NEM), N-methylmorpholine, (NMM), and N, N-dimethylbenzylamine (DMBA). Fugitivity data comparing UAX-1094 is essentially nonvolatile. It also has the catalytic activity necessary to produce good quality polyurethane foam (particularly polyester foams) at reasonable use levels. 

While UAX-1094 is still an experimental product, it is in the initial stages of commercialization. It was recently placed on the Toxic Substance Control Act (TSCA) inventory, and laboratory formulation optimization studies are almost complete.

S97005 Understanding Sensory Irritation Judith C. Stadler, Ph.D., Haskell Laboratory for Toxicology and Industrial Medicine, DuPont Co.

This paper presents an overview of sensory irritation. The author defines sensory irritation, describes ways of predicting sensory irritation, and finally discusses the possible contribution of carpet emissions to sensory irritation. Some of the volatile chemicals commonly found in carpets are listed, and sensory irritation to some of these selected carpet chemicals are described.

S97007 Understanding Sensory Irritation Judith C. Stadler, Ph.D., Haskell Laboratory for Toxicology and Industrial Medicine, DuPont Co.

Antimicrobial Agents to Use in Flexible Polyurethane Foam, Glenn Runciman, Thomas Research Associates

Many studies on the effects of fungal growth on polyurethane materials have been published. Darby and Kaplan in their study published in 1968 showed that polyether polyurethanes were digested enzymatically by fungi. Filip in 1979 proved that polyurethane degradation by microbes takes place by a cleavage of amide and urethane groups.

Polyester polyurethanes are more readily degraded by microbial action than polyether polyurethanes because of the susceptibility of the ester group to hydrolysis which a large number of microbial enzymes (hydrolyses) catalyst.

The effects of microbial growth, such as odor formation and discoloration, are of prime importance as these effects can result in unhygienic, unaesthetic and unsaleable goods.

Several antimicrobial agents are available today for the polyurethane industry. These products, introduced during the manufacturing process, become part of the polymeric structure of the foam.

Proper selection of an antimicrobial agent, based on the requirements of the end-use product, can be of great benefit to a foam manufacturer. Well treated foam is resistant to microbial attack and is more hygienic than untreated foam. In addition, the antimicrobial properties can be marketed as a value-added feature to retailers and consumers.

S97009 Determination of the Extractability of Toluene Diisocyanate from Commercial Polyurethane Foams in Air J. M. Hugo, M. W. Spence, T. D. Lickly, The Dow Chemical Co.

This study was conducted to determine if toluene diisocyanate (TDI) could be extracted from polyurethane foam into air, at the earliest possible time point at which a customer could obtain the foam from a polyurethane foam producer (3 days post production). Foam samples were manufactured, cut to the appropriate size, sealed in Tedlar Bags, and shipped to Dow Chemical for testing. Four foam samples were analyzed, each cubic foot, and indexes varied from 104 to 112. The selection of these samples was designed to reflect the range of commercially-available foams.

Analysis of the filter samples from the four extraction tests showed no detectable TDI with a detection limit of 0.3 ug/5mL acetonitrile or approximately 0.2 ppb in air based on an 8 hour sample at a flow rate of 1L/min and 56% recovery of TDI from the test chamber. (lowest recovery level observed during the chamber validation studies). Analysis of the rinses of the glass chambers after each foam study showed no removable TDI from the walls of the vessels during any of the foam experiments. The TDI detection limit was approximately 1.2ug.

As no TDI was found in air from any of the freshly produced polyurethane foams, the question now became; what would happen to TDI if it were introduced into the foam. In an attempt to answer this question, it was decided to add TDI to the foam, let the foam age for the time period that had previously determined could be the earliest possible point days (post production), and then attempt to extract the foam with air.

The results of the TDI air extraction experiments showed that the filters collected during the 3 day air extraction, after 3 day aging period, showed no detectable TDI coming from the TDI-loaded, low density, low index foam sample. The TDI detection limit was 0.3ug/sample of approximately 0.2 ppb in air based on an 8 hour sample at a flow rate of 1 L/min and 56% recovery of TDI from the test chamber (lowest recovery level observed during the chamber validation).

Further work is continuing to confirm that TDI appears to react with the foam in such a manner to be unremoveable into air. This study will use a high density, high index foam sample. The reproducibility of TDI recovery through the chamber will also be examined.

S97002 An Update on PURRC, Michael Applonia, PURRC-SPI

An update on the programs of the Polyurethane Recycle and Recovery Council was presented to the Polyurethane Foam Association at their May 15, 1997 meeting. The purpose of the PURRC is to reduce polyurethane foam in landfills, and educate end users on the recyclable aspects of polyurethane foam.

Recently completed PURRC projects include the following:

  • Car seat recycling plant Grinding technologies for flexible foam
  • The use of finely ground foam in flexible foam
  • Acoustical performance of rebond in automotive
  • TVOC emissions testing for rebond
  • New PURRC Technical Projects are:
  • Separation of polyethylene film from packaging material
  • Rigid foam regrind into flexible foam
  • VRP joint project-foam and cloth composites for improved acoustics

Non-auto acoustical applications for rebond New Communications Projects are:

  • PURRC brochure
  • PURRC Internet Homepage
  • Increased participation in Industry Association Meetings
S99004 Water Based Adhesive for Flexible Polyurethane Foam Mike Magee, UPACO Adhesives

Discussed in this presentation are three options that UPACO Adhesives offers to methylene chloride based products. They are: one part water based products, hot melts, and flammable solvent adhesives.

The author discusses the furniture/mattress applications, and the advantages of natural latex and synthetic neoprene water based adhesives, pressure sensitive and thermal curing hot melt adhesives, and flammable solvent adhesives. He also gives some insight into the problems, associated with these products, and the equipment needed to apply them.

S97006 Identification of BHT Yellowing on Carpet Fiber Carey Mitchell, Shaw Industries

The slow migration of BHT from carpet padding has been blamed for the discoloration, which is occasionally observed in light colored carpets. This paper examines the role that BHT plays in causing yellowing on carpet fiber, and describes several ways of duplicating the problem in the laboratory. The author also looks at ways of differentiating the yellowing caused by BHT from other causes of yellowing. 

Using a Burnt Gas Fumes Test Chamber equipped with a small Bunsen burner operating off natural gas inside, they were able to duplicate the yellowing observed on carpets. BHT was dissolved in methanol and the carpet fibers were immersed in the methanol solution and then dried. The loaded samples were then exposed in the Burnt Gas Fumes Chamber. The presence of BHT and BHT derived quinones on the carpet fibers were confirmed by HPLC chromatography of a methanol extract of the colored fibers. Fiber type did not have a significant effect on yellowing.

S97008 Improved Prepolymers for Bonded Foam Ray Thomas and Van Delk, The Dow Chemical Co.

Rebond foam manufacture is a widespread and profitable business in the United States. Most of the rebond is used for carpet pad, but some is molded for specialty applications such as transportation seating. The most popular method of making the rebond block is to press the prepolymer coated shredded foam into a mold, setting the prepolymer with steam, drying the resulting block and peeling the resulting block into appropriate lengths to be made into rolls.

Prepolymer preparation for making rebond blocks is very similar, regardless of the mechanical means used to fabricate and shape them. A diisocyanate is mixed in excess of stoiciometric requirements with a polyol to form a quasi prepolymer. Usually free isocyanate, or free NCO, of at least 10% by weight is required to make the prepolymer. Rebond producers using PMDI will often include up to 25% of a non reactive diluent in their formulation. This lowers the overall cost of the prepolymer as well as reduces viscosity. An amount of prepolymer equaling 10% to 20% of the weight of shredded foam is used to coat the foam.

This study was undertaken to further define the critical formulation parameters necessary for the manufacture of rebond binders using MDI and PMDI with focus on prepolymer viscosity and stability. The term MDI denotes lower functionality or “pure” MDI. Where PMDI refers to polymeric MDI of higher functionality.

Laboratory procedures were developed to identify relative differences in reaction rates, viscosity growth, and ultimately binder effectiveness in bonding shredded foam particles. A 12″ X 12″ X 1″ mold was used to evaluate a prepolymers effectiveness as a binder. Moisture and temperature were held constant while functionality and acidity were varied to determine the relative differences in reaction rates for these materials.

In preparing rebond binders for carpet pad and other applications using MDI or PMDI several critical parameters can be used to lower the viscosity, moderated viscosity growth, and improve processability of the prepolymer. The final viscosity can be lowered by using lower functionality raw materials, maintaining the binder at elevated temperature, using high residual NCO, choosing the properdiluent, and protecting the binder from moisture. The viscosity can be stabilized by using catalyst or maintaining the reacting mixture at elevated temperature.

Each plant site, however, must still fit the exact parameters required to the individual equipment and product mix.

S97010 Is it Time for a Non-Halogen Fire Retardant in Flexible Foams? L. Bradford, J. Stonwell, B. Williams, Akzo Nobel Chemical

Concerns regarding a broad range of halogenated products have been raised, mostly in Europe, and primarily in regard to combustion products. While most US business is not threatened at the moment, it is important to be planning how to respond if current technology is threatened. This paper reviews some historic actions regarding regulation that have affected the polyurethane industry, and some patterns that suggest future risks that need to be addressed. For future success, plans must be made to prepare technology to meet changing needs.

Proceedings of the Polyurethane Foam Association Technical Program
October, 1996

F96001 New Insights Into Flame Lamination: Greg Howard, Albright & Wilson Americas

Flame bonding has been at best an inexact science. The reason that some foams bond well while others do not has been most perplexing. Sometimes foams from the same production lot or within the same roll perform differently. This report establishes a means of more accurately predicting performance as well as providing a tool to help evaluate problems that do arise.

Using standard 1.5 PCF automotive foams, the effects of gas type, flame height, flame spread, foam burn off, fabric, and nip pressure, on bond strength were measured. Pieces or the original laboratory foams were also prepared for acid evaluation.

The results of these evaluations demonstrate a direct relationship between acid and bond strengths in laminated foam fabric pieces. Without exception the higher the acid level the stronger the bond.

It is expected that this information can be used to develop new products for improved flame lamination, serve as analytical tools to help resolve quality issues, and provide some understanding and insight into the flame lamination process.

F96003 Foam Hysteresis and Formulation Variables: James E. Knight, ARCO Chemical Company

 Auxiliary blowing agents are essential at this time for the production of flexible slabstock foams. Today the flexible slabstock industry is faced with the possible loss of the ability to use auxiliary blowing agent because of legislative actions arising from environmental concerns of worker health concerns. This issue has prompted considerable work by foam manufacturers, chemical suppliers and machinery manufacturers to develop technologies for the production of foams without or with reduced levels of auxiliary blowing agents such as methylene chloride. To this end there are two objectives: first, to make foams with densities comparable to foams made with auxiliary blowing agents; and secondly, to make foams in the full range of softness/hardness for today’s range of foam applications.

The effects of formulation variables such as water, methylene chloride, TDI index, airflow, flame retardants, polymer polyol, and morphology modifiers (softening agents) on hysteresis were evaluated. The hysteresis of conventional foam vs. HR foam was also looked at.

It was found that formulation water content has a profound influence on the hysteresis of particular slabstock foam while methylene chloride has none. The airflow, addition of flame retardant and morphology modifiers have slight positive effects and increase hysteresis. Increasing TDI index, the addition of polymer polyols, and the addition of inorganic fillers have slight negative effects and decrease the gysteresis of a foam.

F96005 The Flexible Foam Market in Australia David Gilliver, Dunlop Foam & Fibre Group, South Dandenong, Victoria Australia

Australia is one of the largest continents on Earth by land area, but has a relatively small population of 18 million people. The nations per capita consumption of polyurethane foam is among the world’s highest, being only slightly lower than the USA.

This paper discusses the demographics of the Australian Market. Foaming Technologies, Raw Materials, Polyester Foams, Visco-Elastic (Low Resilience) Foams, Quality Changes, Molded Flexible Foams, Other End Uses, Regulatory Issues and Recycling.

F96002 Proposed Federal Regulation for the Flexible Polyurethane Industry: Susan Wyatt, U. S. Environmental Protection Agency

This presentation was made to the Polyurethane Foam Association to notify the industry of upcoming EPA regulatory activity. It was designed to answer questions about the regulation and process, to explain the proposed regulatory requirements, and to inform the industry of opportunities to participate.

 

The legislation limits or prohibits emission of 118 Hazardous Air Pollutants including methylene chloride, toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI) and methyl chloroform (1,1,1,-trichloroethane). The regulation applies to molded, slabstock, and rebond foam producers. It is applicable nationwide, and applies only to major sources of hazardous air pollutants.

 The paper discusses the segments of the polyurethane industry, which are covered by the proposed legislation and those who are exempt. The compliance date, molded foam requirements, rebond foam requirements, slabstock foam requirements, slabstock foam requirements for TDI and HAP ABA and equipment cleaning requirements are presented. A question and answer section on specific issues is also given.

F96004 The Effect of Fogging of Common FR Additives in Flexible Foam: L. Bradford and E. Pinzoni (US) and J. Wuestenenk (Holland), Akzo Nobel Central Research

As a result of design changes in automobile wind screens, temperatures above 100 degrees centigrade have been measured in the interior of cars. Such high temperatures lead to evaporation of volatile materials used in the interior of cars. Condensation (fogging) deposits on the windows of cars.

The automotive manufacturers are asking for FR’s with good fogging properties with reference to reflectance (>60%) and gravimetric results (<1mg*.) specification may vary. This paper attempts to clarify some of the confusion in the industry regarding test data, and the contribution of flame retardants (FR’s).

Data is presented which shows the relative fogging performance of some of the most common FR additives and two experimental additives. Testing is on foam samples not raw materials. Foams were prepared containing no flame retardant, 5 parts of FR and 15 parts of FR, at a density of 1.8 lbs./cu ft. One additional set of data compares 1.2 and 1.8 density foams to show impact of foam density on fogging.

The Fogging test conditions shown, with resulting product classification, include those required by Ford General Motors, Mercedes, and Toyota.

The conclusions from these evaluations are as follows:

  1. Non reactive oligomers can be good FR’s for fogging behavior in the automotive foams, either in gravimetric or photometric methods.
  2. Reactive oligomers should also give good fogging behavior in both methods.
  3. TDCP (Fyrol FR-2) also gives good results in the photometric method, and slightly better results in the gravemetric methods.
  4. Oligomer 2 (Fyrol 99) had slightly worse performance than TDCP (Fyrol FR-2).
  5. TCPP (Fyrol PCF) gave the worst results in either gravimetric or photometric methods.
  6. TCPP should not be used if fogging is a major concern in the final application. The reproducibility of the gravimetric method is good.
  7. The reproducibility of the photometric method is poor
  8. Density has a direct impact on fogging.

Proceedings of the Polyurethane Foam Association Technical Program
May, 1996

S96001 A New Flame Retardant Additive for Flexible Polyurethane Foam: R. S. Rose, L. J. Likens, J. L. Elliott, Great Lakes Chemical Corporation, West Lafeyette, Indiana

 

This paper introduces a new bromine based flame retardant that provides the same efficiency as well as the hydrolytic and thermal stability as the diphenyl oxide based flame retardants without the regulatory threats associated with the latter.

The new flame retardant has been designated CN-2065. It is a low viscosity bromine containing liquid which can be used alone or with phosphorus compounds CN-2065 is evaluated in both 1.5 PCF automotive polyester polyurethane foam and in typical polyether polyurethane furniture foam formulations meeting California Bulletin 117 flammability requirements.

The polyester foam evaluation indicated that the new flame retardant, CN-2065, provides the stability of aromatic bromine without a diphenyl oxide base. It is an alternative for polyester polyurethane foams requiring long term hydrolysis resistance in humid environments.

This new flame retardant also performs in polyether polyurethane foam. In addition to being scorch resistant, there is an indication that its plasticizing characteristics are suited to flame lamination applications.

S96003 Advances in Blowing Agent Reduction with Geolite Modifier Technology: Ray Ricciardi, OSI Specialties

OSI Specialties Geolite modifier additives have grown in sales as government regulations force more and more slab foamers to reduce auxiliary blowing agents from their formulations. Earlier products, Geolite modifier 91 and Geolite modifier 205, demonstrated much progress towards this objective by reducing blowing agent concentration approximately 30% and 60% respectively in an OSI grouping of typical slab formulations. The new Geolite modifier 210 product and technology reportedly reduces blowing agents by over 90% in the OSI grouping of typical slab formulations.

Geolite modifier 210 can be used in most foam grades. It offers varying levels of ABA reduction depending on the foam grade and whether mechanical cooling is used. A 100% reduction in ABA can be achieved in most foam grades without mechanical cooling. The exceptions are where foam exotherms become unsafe when excess water is used as a blowing agent. Some ABA may be required for high or low density super-soft foams. Mechanical cooling can complement this technology by cooling the low density hard foam grades.

Since more rapid foam cure can be achieved with GM-210, foams can be cooled to achieve acceptable foam physical properties before the foam blocks reach unsafe temperatures. Cooling can also minimize foam degradation or discoloration, which can occur from high foam exotherms.

OSI believes that GM-210 technology is a significant technical development that will help the slab foam industry to economically reduce chemical blowing agents.

 

S96005 Versatile HR Slabstock Foam Technology: T. M. Smiecinski, D. C. Mente, S. E. Wujcik, BASF Corporation

Traditionally manufacturers of HR foam focused on up-scale furniture and bedding applications. During the early 1980’s some foamers tried to develop and market highly flame retardant foams for high risk applications such as auditoriums, hotels and prisons. These efforts had limited success due to difficulties with product quality and high manufacturing costs. This paper describes the most recent innovations in HR technology which combines BASF’s Rest Easy Plus HR foam technology with mixed isocyanate technology.

Raw Materials, formulations and foam properties for producing a variety of HR foam grades including all water blown super soft foam, HR latex foam, melamine modified HR foam and HR foam produced with mixed isocyanate are described. BASF feels that this technology has many strengths that will take it well into the twenty first century.

S96007 The Use of Polymer Additives to Achieve Optimal Physical Properties of Flexible Polyurethane Foam: V. C. "Jun" Fabella, Jr., Monsanto Company

 

For some time now, foam produced with auxiliary blowing agents (ABAs) has been the benchmark of foam quality demanded by furniture manufacturers and their customers. New and pending local, state and federal environmental legislation are forcing flexible slabstock foam manufacturers away from use of some ABAs, especially methylene chloride.

Current technologies utilizing mechanical and chemical methods to produce foams without ABAs often produce foam of inferior quality. To overcome some of these physical property deficiencies, Monsanto is offering a new polymer modifier called Santofoam 1000.

This report covers the effects of Santofoam 1000 in flexible polyurethane foam. In brief, Santofoam improves the bulk physical properties in conventional flexible polyurethane foam formulations. Furthermore the use of Santofoam 1000 facilitates the removal of methylene chloride, an ABA.

Santofoam 1000 does not react with the isocyanate or the polyol. Santofoam 1000 becomes an integral part of the polymer system, and does not volatilize. Santofoam 1000 facilitates the polymerization (gelling) and the gas producing (blowing) reaction while ultimately improving and/or optimizing the physical properties of the foam.

S96009 Low Odor Catalysts for Flexible Polyester Foams: Robert L. Zimmerman, Robert A. Grigsby, Huntsman Corporation.

The polyols used for the manufacture of polyester foams are made from diethylene glycol, glycerin and adipic acid. This gives a polyol with primary hydroxyl groups as opposed to polyether polyols, which have mostly secondary hydroxyl groups. As a result, polyester foams require different catalysts than polyether foams.

One difference is that polyester foams use up to ten times as much amine catalyst as polyether foams, therefore, odor becomes a much more important factor with polyester foams.

In this paper polyester foam catalysts are examined using the following criteria:

  • Amount required
  • Vapor pressure of the catalyst
  • Foam discoloration
  • Rise profile
  • Cure profile

Low odor catalysts for polyester-based flexible urethane foams have been identified. These catalysts are highly efficient which not only helps to reduce odor but also helps reduce amine emissions from the foam plant. Foam cure is also affected by the catalyst, and it has been shown that good cure can be obtained while still maintaining a relatively low odor. Reaction profile can also be varied. Using this information, catalysts can be custom designed to meet individual requirements of a foam manufacturer.

S96011 The Combustion Behavior of Upholstered Furniture (CBUF) an American Perspective: T. Hugh Talley, AFMA.

The author reviews the CBUF study and comes to the following conclusions:

 “While the CBUF program advances our understanding of fire science, and our ability to evaluate and predict the burning behavior and fire hazards of upholstered furniture, much work remains to be done to substantiate the postulates providing the foundation for the work (e.g. ignition sources and detectability limits), the test protocols, computer models, and the reported conclusions.”

  1. The conclusions drawn and methodologies used are certainly not ready for use in any regulatory manner.
S96013 Assessment of Potential Health Risks Resulting from Chemical Emissions from New Bedding Sets: Sponsored by The Sleep Products Safety Council.

In response to adverse television publicity about alleged health effects from newly purchased mattresses, the Sleep Products Safety Council (SPSC) sponsored research to evaluate the potential health effects from chemical emissions from newly manufactured bedding sets.

Bedding sets representative of a high percentage of those commonly sold in the U. S. were evaluated for chemical emissions in a series of controlled laboratory test performed by Research Triangle (RTI). Individual components from each of the bedding sets were also tested by TRI. A hazard and risk assessment of the RTI emissions measurements by Versar Inc. showed no acute inhalation, dermal or odor health risks associated with the short-term exposure to mattress emissions, at the rates measured by RTI, for normal or convalescing individuals. This study was performed with the counsel and review of an independent Scientific Review Board composed of eminently recognized environmental and health scientists.

S96015 The Combustion Behavior of Upholstered Furniture (CBUF) an American Perspective: T. Hugh Talley, AFMA.

The author reviews the CBUF study and comes to the following conclusions:

 “While the CBUF program advances our understanding of fire science, and our ability to evaluate and predict the burning behavior and fire hazards of upholstered furniture, much work remains to be done to substantiate the postulates providing the foundation for the work (e.g. ignition sources and detectability limits), the test protocols, computer models, and the reported conclusions.”

  1. The conclusions drawn and methodologies used are certainly not ready for use in any regulatory manner.
S96017 Two Years of Industrial Experience with liquid CO-2 Blown Slabstock Foam: Heinz Meloth, Cannon USA.

This paper presents the results of two years of industrial use of CarDio (TM), Cannon Group’s proprietary technology for producing liquid CO-2 blown flexible slabstock foam The range of foam densities obtainable using this technology along with foam quality, processing aspects and its economies are illustrated.

S96002 New Developments in Non-Halogenated Flame Retarded Flexible PUF: M. Sicken, Hoechst AG, Hurth, Germany, C. Schultz, Hoechst AG, Frankfort, Germany

Hoechst has taken the challenge to develop flame retardants which not only meet the basic requirements concerning flame retardant efficiency and polymer compatibility, but also with regard to cost effectiveness and to environmental questions such as emission properties and recyclability. Hoechst is of the opinion that flame retardants that contain only phosphorus have substantial advantages compared to the widely used halogenated phosphate esters and the brominated and / or chlorinated polyols.

The comparative burning behavior of flexible foams prepared with Hoecst’s Hostaflam TP OP 550, a reactive all phosphorus based flame retardant containing 17.5% phosphorus, compared to TCPP, TDCPP and a chlorinated diphospate ester is evaluated. 

The authors conclude that Hostaflam TP OP 550 meets industry requirements for flame retardant efficiency and cost effectiveness, and also earns high marks on environmental aspects demonstrated by low emission data in terms of fogging values and smoke gas properties.

S96004 Controlled Environmental Foaming: Scott Carson, Foam One, Dario Ramazzotti, Edge Sweets Co.

In May 1994, Foam One introduced for licensing the patented Controlled Environment Foaming (CEF) manufacturing process to the PFA. Foam One technology meets environmental goals by eliminating the need for auxiliary blowing agents, all cleaning solvents, and by the use of carbon scrubbers to capture all TDI emissions present during the foaming stage of production. Additional features of this technology permit the foam producers to manufacture many unique foams. As a result, foam manufacturers are now able to penetrate markets, which previously were not available to the foam industry.

The purpose of this paper is to update the industry on the current status of the Foam.

One process and outline feature of many of the unique foams currently being produced use this technology. All existing foam products including filled foams can be manufactured by the Foam One process. When using vacuum, a low density, ultra soft grade of foam can be manufactured. When convoluted, this product can be used in place of polyester wrap for furniture cushions or in any other place where polyester batting is currently being used.

The use of pressure during foaming allows the production of very high compressive strength foam. This particular foam is successfully replacing polyethylene foam in packaging applications.

Several other Foam One process capabilities are also discussed which provide the urethane foam producer with a method of manufacturing new and profitable products for their company. Foam One technicians provide the necessary procedures and training for the start up of Foam One machinery.

 

S96006 NovaFlex-Technologies in the Slabstock Industries: R. L. Kirschner, Hennecke Machinery, Dr. J. S. Pisipati, Bayer Corp., J. T. Ferrand, Bayer Corp., H. M. Sulzbach, Machinenfabrik Hennecke GmbH

 

Low density foam grades account for 70% of the market in the United States and about 25% of the market in Europe. The typical flexible foam slabstock plant has used auxiliary blowing agents such as methylene chloride in order to produce foam densities less than 2.0 pcf. The Clean Air Amendment of 1990 legislates a significant reduction in methylene chloride emissions. Compliance can be achieved by using alternative technology or capturing the blowing agent before emissions reach the atmosphere. Up to now, the search for a suitable replacement to produce low density furniture grade foams has not been resolved.

This paper describes the NovaFlex process, which facilitates the use of liquid carbon dioxide as an auxiliary blowing agent in polyurethane foam production. Information on the Hennecke NovaFlex process and production experience in Europe and the United States is discussed.

  • The NovaFlex technology offers several benefits to foam manufacturers including the following:
  • An environmentally acceptable blowing agent
  • Excellent foam quality
  • Potential for improved production economics
  • Combined equipment and chemical expertise

T

S96008 Fire Dynamics: A Residential Perspective: Harrison Murphy, Ventex, Inc.

The widening acceptability of full scale fire tests like California TB 129 for mattresses and 133 for furniture has made the determination of whether a product is open flame resistant quite scientific and clear. Either the product meets the peak rate of heat release requirement of the test or it doesn’t, and it fails.

There are barriers available which can significantly reduce the peak rate of heat release of residential mattresses and furniture. With such a barrier, a residential mattress, for example, would release only 35 KW as measure by the California TB 129 test, as compared to 2,000 KW without a fire barrier.

Fire barriers working in conjunction with unmodified and slightly combustion modified (117) foam can address the fire hazard at a minimal cost to industry and consumers. In addition, it can head off millions of dollars of liability suits that are inevitable under the current circumstances.

S960010 European Controversy Concerning Flammability Regulations for Furniture and Bedding, Dr. H. Creyf, Chairman Europur Technical Committee

Europur has a number of reservations regarding some of the conclusions and recommendations of the CBUF Report, however, they feel it represents a major step forward in fire science. CBUF themselves indicate the need for further model development and for cone calorimeter proceedures to be tried by more laboratories, and to be used over a broader range of materials.

The author concludes that the PU industry is concerned about the safety of consumers as well as the benefits they receive from polyurethane products. He also feels that the CBUF research is a major contribution to our understanding of the flammability of furniture, but cannot be accepted in its present state as a basis for further legislation or the development of CEN standards. Finally he feels that the PU industry believes that a consumer demand driven increase in the use of cigarette resistant furniture coupled with an increase in the use of smoke detectors is the best way to have an impact on domestic furniture fires.

S96012 A Novel Approach to Antioxidant Dissolution in Polyols: Robert L. Gray, E. Lee, Brent M. Sanders, Great Lakes Chemical Corporation.

Work continues to be done to provide effective stabilization of polyols used for flexible bun stock production as a result of the increased exotherm resulting from the reduction of chlorofluorocarbon (CFC) blowing agents and the associated increase in water content of these formulations. BHT shows outstanding performance in scorch inhibition. However, its high volatility can lead to problems with fogging and the formation of highly colored by-products. This paper describes several lower volatility alternatives, which can be used in place of BHT.

Several lower volatility alternatives to BHT were evaluated using a microwave scorch test, which has been used in the laboratory to reproduce the thermodynamics of large production foams. The importance that antioxidant solubility in polyol has on scorch resistance has already been demonstrated in the laboratory. Two antioxidants, AO2 and AO3 show good performance and are liquids and miscible in polyol. The least volatile and more effective phenolic antioxidant is AO5. The amorphous form of AO5 dissolved in standard polyol is 20 degrees centigrade lower than the crystal form. This represents a significant advantage in energy savings and worker safety. 

It is important to keep in mind that the results reported in this study were developed in a laboratory setting where the actual conditions of industrial scale production may not be accurately represented.

 

S96014 The Beamech CO-2 Process for the Continuous Manufacture of Flexible Slabstock Foam: J. Brian Blackwell, Beamech Group Ltd.

Recently liquid CO-2 has been promoted and used successfully to completely eliminate CFC’s and regulated VOCs from the production of flexible slabstock foam. In recent months, more manufacturers have announced the availability of equipment for the production of flexible slabstock foams using liquid CO-2 technology. The Beamech group have just entered the market with equipment for metering and mixing liquid CO-2 under high pressure to produce a stable froth which can be used to produce low density flexible slabstock foam. This paper describes their equipment and process.

S96016 Silicone Surfactant Effects on Cell Structure in Liquid CO-2 Blown Slabstock Foams: Rob Borgogelli, Frank Carey, and Dr. Volker Zellmer, Goldschmidt Chemical Corp.

Since the introduction of liquid CO-2 blown slabstock foams to the flexible polyurethane industry, Goldschmidt has been actively engaged in the production of foams by these new processes. Early development stage research continues to create new products designed specifically for liquid CO-2 blown flexible foam surfactants. It focuses primarily on observations from trials of existing and experimental products on U. S. foam production equipment. Data from laboratory techniques developed by Goldschmidt that seem to correlate well to industrial experience is also reported.

The results of this study indicate that Goldschmidt’s BF 2370 still appears to be the product of choice to achieve fine regular cell structure with a minimum of pinholes and voids. EP-H-101 provides higher stabilization than BF 2370, and may be useful for achieving finer cell size in certain formulations.

With respect to universal surfactants, EP-H-100 appears to provide a finer cell structure than B 8228 in most CO-2 systems. In comparison to BF 2370, the higher potency and improved flammability performance of EP-H-100 makes it an ideal candidate for the U. S. market. Research continues to develop experimental surfactants that provide improved performance for this technology.

Proceedings of the Polyurethane Foam Association Technical Program
October, 1995

F95001 Evaluation of Antioxidants with Low Volatility for Scorch Protection of Polyurethane Foams, Robert E. Lee, Great Lakes Chemical Corp.

Work is continuing to effectively stabilize flexible bunstock formulations produced with reduced chlorofluorocarbon (CFC) content. The higher water content of these formulations, and the associated increase in exotherm, have limited the use of the commonly used butylated hydroxytoluene (BHT) because of its high volatility and tendency to form highly colored by products.

The author examines four phenolic antioxidants (A02, A03, A04, A05) which have higher molecular weights than BHT, and compares the volatility, solubility and anti scorch performance of these new products with BHT.

The results of this study indicated that two antioxidants, A02 and A03 show good performance, are liquids and miscible in polyol. A05, the least volatile, requires higher temperatures (95-105°C) to dissolve in polyol, and has reduced scorch resistance. This is a significant disadvantage in energy savings and worker safety.

F95003 Commercial Potential for Recycling of Finely Ground Foam in Flexible Polyurethane Foam, A Project of the Polyurethane Recycle and Recovery Council of SPI, H. Stone, S Lichvar, General Foam Corporation, F. Sweet, (The Dow Chemical Co./PURRC)

The feasibility of using finely ground polyurethane foam as a filler in the preparation of new foam has been demonstrated in several previous studies. Two methods of preparing such ground foam have been demonstrated using both cryogenic grinding and mechanical grinding under ambient conditions. Ground foams for this study were prepared by a cryogenic plate mill process, and introduced into the foaming process by slurrying into the polyol stream.

Current work (sponsored by the PURRC) was designed to systematically demonstrate the effects of addition of ground foam on two foam grades representing a significant percentage of the foams produced in North America. Initial plans were to evaluate scrap from six different sources, to determine maximum practical concentration, in pilot scale trials. Five trials, each at three concentrations, have been completed. Three full scale trials at the highest practical concentration have also been completed.

The following conclusions were made based on the data generated:

  1. The technical feasibility of producing a variety of flexible polyurethane foams using finely ground scrap foam has been demonstrated.
  2. Both density and IFD can be maintained equal to that of unfilled foam.
  3. The additives can be used in existing equipment at levels up to at least twenty parts per hundred of polyol.
  4. Both in house generated scrap and post consumer scrap can be used.
  5. The use of ground foam as a filler results in only minor effects on foam quality. These can most likely be overcome with small formulation adjustments.
  6. There is sufficient economic incentive to justify further development and eventual commercialization of the process.
  7. Demonstrations in full scale completed so far confirm the results of work to date.
F95005 A New Public Relations Program for Flexible Polyurethane Foam, Helen Sullivan, Arnold Public Relations

The Polyurethane Foam Association (PFA) is considering forming a partnership with the Society of the Plastics Industry’s Polyurethane Division (SPI) to launch an industry-wide public relations program. The purpose of this program is to promote the use of polyurethane foam in upholstered furniture. By supporting market research with SPI, the PFA has taken the first important step toward launching this program. The results of the market research study will generate more information about the upholstered foam industry, and provide guidance for developing the program.

Helen Sullivan presented an overview of the program at the October PFA meeting in San Antonio. She reviewed the following elements of the research that is being conducted on behalf of the SPI and the PFA.

Attitude and Usage Study (Quantitative)

This study will help determine the decision makers’ attitudes toward and usage of polyurethane foam and other cushioning materials.

In-Depth Interview (Qualitative)

This study will be used to enrich the information on the topics in the quantitative study, to explore other topics not covered and to develop a broad perspective on the language of furniture manufacturers.

Together the studies look at such issues as furniture manufacturers’ perceptions of foam vs fiber, the “plush” furniture trend, the role of price, flammability considerations, the decision process and much more.

The results of this research will be presented this November to the Flexible Foam Commercial Committee. Should the research indicate that an industry wide program is needed, it is hoped that the PFA and SPI will move forward together.

 

F95007 High Quality Flexible Slabsock Foam Using Liquid Carbon Dioxide as an Auxiliary Blowing Agent, R. G. Eiben, J. T. Ferrand, Bayer Corp, H. M. Sulzbach, D. A. Radovich, Hennecke Gmbh

 

Regulatory pressures to alleviate the use of methylene chloride and VOCs have heightened interest in the slabstock industry for liquid carbon dioxide. A Bayer and Hennecke team has successfully designed equipment to handle liquid carbon dioxide, and has developed suitable formulations which enable slabstock foamers to manufacture high quality flexible foam with even cell size distribution throughout the entire cross section of the bun. The two most important advantages of all well known blowing agents are also provided by formulations containing dissolved carbon dioxide; the ability to produce low density foam grades and the ability to vary hardness and resilience while maintaining the same density.

A critical component of the new machine is the patented expanding device. When attached to a modified mixing head, it carefully controls the outgassing of the added carbon dioxide. A new equipment design facilitates the metering of the liquid carbon dioxide dissolution into the polyol or isocyanate, mixing of the components, and finally the expansion of the reaction mixture onto the conveyor. The reaction mixture generates a stable homogenous froth that can be shaped into a rectangular block before the water reaction begins to expand the foam to maximum height.

Efforts are continuing towards offering foam grades that cover a wide range of density and hardness. Advantages to the approach Bayer and Hennecke have taken, which includes equipment modification combined with development of suitable raw materials for this application, are described in this paper.

F95009 Characteristics of Surfactants For Use With New Processes Using Carbon Dioxide as an Auxiliary Blowing Agent, Susan B. McVey, Brian L. Hilker, and Lee F. Lawler, OSI Specialties

 

Since the inception of the Montreal Protocol and the Clean Air Act Amendment of 1990, the polyurethane industry has been searching for ways to reduce or eliminate currently used auxiliary blowing agents (ABAs) from foam manufacturing processes. Liquid carbon dioxide has shown the most promise as a substitute because it is safe to use (i.e. non flammable) and inexpensive.

Early efforts to use liquid carbon dioxide gave severe foam processing problems. As a result, foam machine manufacturers have been working on ways to improve foam quality. Today, there are three machine manufacturers with equipment either commercial or soon to be commercialized. They are: Cannon CarDio®, Hennecke Nova Flex, and Beamech CO-2™ machines. These new machines offer major improvements over earlier efforts to use liquid carbon dioxide.

The mechanical and chemical differences between conventional and the liquid CO-2™ based foaming processes indicate that the role of surfactant is process dependent. The effect of surfactant additives on surface tension, emulsification, froth/bubble formation and stability, and foam stability characteristics were studied towards helping to optimize these CO-2™ systems.

It appears that there is a relatively good correlation between the froth density, time to collapse and the foam properties obtained from the carbon dioxide system. Surfactants exhibiting a low froth density with a moderate froth stability gave foams with acceptable cell size and uniformity. Optical microscopy appeared to be a good tool for collecting information on bubble size and counts. Further work is planned as more information on carbon dioxide blown foams becomes available. Surface tension information has not yet been correlated with liquid carbon dioxide blown foams.

OSI plans to continue work with many new and existing molecules to find the best surfactants and additives to help optimize the utility of this new technology area.

 

F95011 New CarDio Installations, Jerry Pool, The Research Pool

The national emphasis on environmental responsibility along with legislation limiting or eliminating the use of chlorofluorocarbons (CFC’s) has prompted many flexible slabstock foamers to select some of the alternative technologies that have been developed to reduce or eliminate the halogenated solvents used as auxiliary blowing agents (ABA’s).

Leggett and Platt has foam plants in Massachusetts and Texas, and in order to meet the state programs, has selected liquid carbon dioxide as a method of compliance. Comparing carbon dioxide with other blowing agents it comes out ahead with respect to ozone depletion, global warming, safety, and cost. It has zero potential as an ozone depleting substance, causes no increase in global warming, is non-toxic, non flammable and less expensive than other ABA’s.

This paper describes some of the problems that were encountered by Leggett and Platt in adapting the CarDio process to their requirements including, equipment, computer software, and plumbing requirements, machine controls, foam qualities and physical properties. A schematic of the conversion requirements, and close-ups of some of the equipment are show along with formulation and physical property data.

In conclusion, Leggett and Platt believe that the liquid carbon dioxide process is a good choice. They also recognize that it is a very new technology, and will evolve over the next few years. They feel that it is an interesting challenge to be part of that development.

 

F95002 New Generation Flame Retardant Polyol, J. J. Lear, O. D. Sloan, P. Motte, Arco Chemical Company

 The creation of more severe flammability standards has increased interest in combustion modified polyurethane foam for both residential and commercial furnishings, Flexible polyurethane formulations have been modified over the years to meet the needs of new regulations as they have been introduced. However, the types of fire retardant additives used have remained fairly constant. Foams containing solely liquid flame retardants based on phosphorous and bromine or chlorine are not adequate to meet the more severe flammability requirements of TB 133 or Crib 5 testing. The technologies now used to produce these foams, commonly referred to as Combustion Modified High Resilience (CMHR) Foams, require the addition of substantial amounts of solid flame retardant, predominantly melamine, as well as increased levels of liquid flame retardant.

A new polyol technology recently developed by ARCO Chemical Company called ARCOL® Experimental polyol R 2041 has been used in melamine-free CMHR slabstock formulations that meet Crib 5 test requirements. The same technology was also used with common fabric/foam combinations that successfully passed TB 133; without the use of interliners; requiring 60% less melamine than current formulations to no melamine.

In conclusion, Arcol Experimental Polyol R-2041 minimizes or overcomes several of the negative aspects of using solid flame retardant additives such as melamine or excessive levels of liquid FRs in combustion modified foams. Foams using Arcol® Experimental polyol R 2041 allow the levels of melamine filler required to pass California TB 133 standard to be reduced from 60 to 100%. This new polyol can also eliminate the use of interliners and can be used to meet the Crib 5 test requirements without the use of melamine.

 

F95004 Load Compression Profiles For Cushions Fabricated with Flexible Polyurethane Foam and Fiberfill, Stanley L. Hager, Michael J. McGovern, Maureen T. Pence, and Oliver D. Sloan, Arco Chemical Company

Designers and fabricators can choose between a wide variety of flexible foams, fiberfills and fabrics for constructing cushions and backs for upholstered furniture. With this flexibility also comes uncertainty as to the cushioning characteristics, comfort and durability expected from new cushion designs. In this paper, quantitative load compression profiles (cushioning or loading curves) are used to demonstrate the influence that a number of these variables have on cushioning performance. Fiberfill and different types and firmness of flexible polyurethane foam are evaluated separately and in composite cushions in which fiberfill or soft foam is used as a wrap over firmer foam cores. Changes in the cushioning profiles resulting from constant force pounding are used to assess long term durability of the fabricated components.

Backs and very soft cushions constructed solely with ultrasoft foam (6 lb. IFD-Softcel ™ Foam) were found to offer similar cushioning profiles to loose blown fiberfill backs and resin bonded fiberfill cushions. Wrapping foam cores with as little as one inch of ultrasoft foam or one oz/sq. ft. of fiberfill eliminates the initial knee in the cushioning curve of the core foam resulting in a soft surface feel and increased “ride”. High modulus foam cores provide the smoothest cushioning transition from the sort wrap to the firmer core. Wrapped cushions fabricated with the ultrasoft foam closely match the profiles of fiberfill wrapped cushions. With appropriate fabrication techniques such as over stuffing and/or glued down edges it is also possible to match the smooth and crowned appearance achieved with fiberfill. Ultrasoft foam offers the added benefit of maintaining the same appearance and nearly the same cushioning performance after extensive pounding; whereas fiberfill exhibits significant compaction and reduced cushioning performance. This improved durability should result in fewer returns and improved customer satisfaction.

F95006 Sanitation Study of Post Consumer Foam in Rebond Carpet Underlay, K. P Roberts, C. M. August, J. R. Geiger and A. M. Tracz, Microbiology Group, Olin Chemicals Research

The Carpet Cushion Council (CCC) and the Polyurethanes Recycle and Recovery Council (PURRC), a subcommittee of the SPI Polyurethane Division, initiated a study to determine if microorganisms present in post consumer scrap used in rebond carpet cushion pose a health risk. Samples of rebond carpet cushion manufactured from 100% post consumer scrap by three processes were obtained. Samples of the raw post consumer scrap used to make this underlay were obtained as well. For comparison, tests were also conducted on prime carpet cushion underlay and rebond underlay made from 100% process (post industrial) scrap. Samples were examined for the number and types of bacteria and fungi present.

The results of this study show that the inclusion of post consumer scrap in rebond will not expose consumers or manufacturing personnel to unusual microorganisms or high numbers of either bacteria or fungi. The organisms isolated are those typically found in environmental samples. No harmful bacteria or fungi were found in any of the scrap samples or finished underlay. The number of microorganisms found in underlay made from recycled material were not much higher than those found in cushion made from 100% process scrap or in prime carpet underlay. It was also found that the rebond manufacturing processes themselves, greatly reduce the level of microorganisms in the finished product.

F95008 Specialty Slabstock Foams Based on Novel Technologies, Philippe Knaub, Dow North America, H. Mispreuve, J. P. Treboux, T. Woods Jr., Dow Europe S. A., IDC

This paper describes several new technologies that have been developed by Dow Chemical for the preparation of flexible slabstock. These technologies are based on novel molecules, usually compatible with current technologies, and designed for use on current foaming equipment with minor or no modifications. The first is a new high resilience (HR) technology based on a novel unfilled polyol that features a tremendous processing latitude, and is compatible with any classical filled or unfilled polyol without compromising any physical property.

The other technologies presented are all based on diphenylmethane diisocyanate (MDI) used either in its pure or polymeric forms.

The first part of this presentation shows examples of HR foams prepared with Dow’s novel HR polyol, Voralux® HF505, alone and in combination with either conventional or copolymer polyol. The Vorolux® HF505 is fully compatible with conventional polyol and copolymer polyol. The former is usually incompatible with HR polyol, and usually shows stability problems when as little as 5% standard polyol contamination occurs. The exceptional processing latitude obtained with Voralux® HF505 is demonstrated by the diethanolamine (DEOA) window that this technology enjoys, when compared to classical HR systems.

Foam firmness can be decreased by using the Voralux HF505 alone, or increased by blending with copolymer polyol. This technology has been trialed on large scale equipment with great success.

The second part of this presentation assesses the real potential for MDI and polymeric MDI (PMDI) in the field of conventional slabstock. The objective of this study is to show that very firm grades of foam can be manufactured, without the use of Styrene/Acrylonitrile (SAN) grafted polyols, using PMDI. Conventional polyols as well as conventional additives (surfactant and catalysts) are used in the examples.

 

It is expected that whole new market segments will open up to polyurethane foams with this technology. Fields as diverse as ultra high load bearing foams for carpet underlay and sport mats, and low porosity foams (non-shrinking low breathability foams) that can be used for in-situ poured packaging foams may be able to use this technology.

F95010 All MDI Prime Carpet Cushion, Robert J. Lockwood, ICI Polyurethanes

The purpose of this paper is to introduce a novel technology for preparing an-All MDI-PrimeGraft carpet cushion. ICI has been spearheading the introduction of MDI into the slabstock market over the past five years. MDI’s inherent chemical differences from TDI, as well as, the significant polymer morphological differences, affords opportunities for slabstock foams with improved physical properties and unique process advantages. Its higher molecular weight leads to lower bun exotherm and higher load bearing foam. The monomeric and polymeric basis of MDI isocyanates makes them ideal for HR quality foams with very good dry and humid ages compression sets. The greater reactivity of MDI over TDI gives very short bun curing times and just in time production, as well as, very fine-celled low air flow foams without any tendency towards shrinkage. In addition, the lower volatility of MDI versus TDI makes safe handling and workplace air management much easier to achieve.

The results of this study indicate that an all MDI-Prime graft is an excellent product exhibiting equivalent , if not better, carpet wear resistance and pad durability results compared to other representative technologies tested. This product also exhibits a unique plushness and feel as a result of its fine cell structure in combination with a low airflow. MDI chemistry affords many advantages to specific slabstock products and it is believed that this initial niche application will be the first of many into the incumbent TDI based slabstock market.

Proceedings of the Polyurethane Foam Association Technical Program
May, 1995

S95001 Catalyzing Products Stewardship in Polyurethane’s, Charles M. Bartish, Air Products and Chemicals, Inc.

 

 

The product Stewardship Code of Responsible Care® was created to help members of the Chemical Manufacturing Association (CMA) incorporate environmental, health and safety protection into every facet of design, manufacture, marketing, distribution, use, recycle and disposal of chemical products. Unlike the other codes of Responsible Care®, which deal mainly with manufacturing and transporting chemical products, the Product Stewardship Code® covers a products entire life cycle, from cradle to grave.

 

In addition to providing information required by regulations, companies will now systematically review products and their uses, to be sure that all information necessary for safe handling, use and disposal of the product is known and communicated. Companies will also review each step in the product life cycle for every product family to see if additional actions can be taken to further reduce the possibility of an accident or injury.

 

This paper discusses the general principles of Responsible Care and Product Stewardship, what chemical producers and marketers will do as a result of implementing Product Stewardship, and how customers will participate in the Product Stewardship process.

S95003 Control and Monitoring of VOC Emissions in Urethane Foaming Operations, Charles Quinlan, KSE, Inc.

Urethane foaming plants are encountering both air emission control regulations and increasing scrutiny of the quality of indoor plant air. A cost effective method is needed to control plant emissions of methylene chloride and acetone, and also control workplace indoor air pollution caused by chlorinated hydrocarbons.

A new emissions control technology for urethane foaming plants has been developed by KSE, Inc. It is applicable both to curing room emissions and to the intermittent emissions from foaming line operation. The photocatalytic technology utilizes a bed of absorbent to efficiently remove pollutants from air as they are emitted from the foaming operations. Simultaneously, the absorbent is illuminated by ultraviolet light, which destroys the pollutants captured by the absorbent at ambient temperatures. The technology offers lower cost, and a simple, continuous method to destroy foam in plant emissions or to improve the quality of indoor plant air.

S95005 Electronic Communication for the PFA, Tea Canna and Bob Luedeka, OSI Specialties/J. P. Hogan

The objectives of this program are, first, to provide an efficient, secure, economical communications system for members and associate members, and secondly to educate selected audiences regarding PFA fire safety, and the InTOUCH program.

The PFA website content will include a complete set of InTOUCH issues, Fire Safety TV public service announcement (full video) in English and Spanish, Fire Safety radio announcement (30 sec. Version), and the PFA Mission Statement.

The PFA Electronic Information System is expected to provide the following benefits for its members:

  1. Provide economical worldwide e-mail access.
  2. Position PFA as state-of-the-art.
  3. Share vital information.
  4. Can be tracked to determine use.
  5. Provide an exciting publicity opportunity among customer groups.
  6. About the same cost as a single InTOUCH issue.

The program will begin on a minimal basis to test the water and determine use. PFA’s “NET” presence will be publicized, site information will be updated, and other site uses will be investigated.

S95007 Durability Testing of Flexible PUF and Polyester Fiber for Furniture Applications, Roy Pask, BASF, Michael McGovern, ARCO Chemical

The use of polyester fiber in composites with polyurethane foam (PUF) in furniture applications is widely accepted by upholstered furniture manufacturers. Many believe that cushions now have more fiber and less foam than in the past. This has become a concern to FPF manufacturers and raw material suppliers. In 1993 the SPI Flexible Foam Commercial Committee conducted testing to evaluate furniture cushions fabricated from foam and fiber. The committee solicited help from both the PFA and from the AFMA Joint Industry Foam Guidelines Committee in developing the testing program. This paper describes the development and results of the testing program.

Test results indicate that flexible polyurethane foam for furniture applications exhibited a noticeable performance advantage over fiber in both the iso pounding test and the GSA test, primarily in thickness retention. Test results also demonstrate that polyester fiber contributes very little to load bearing performance. FPF manufacturers have an opportunity to develop alternatives to polyester fiber.

S95009 Developing Federal Hazardous Air Pollutant Standards for the Flexible Polyurethane Foam Industry, Phil Norwood, EC/R Incorporated

This presentation will discuss the development of federal standards to reduce hazardous air pollutant (HAP) emissions from the manufacture of flexible polyurethane foam. The primary purpose of the presentation is to explain some of the major legal and policy requirements that the U. S. Environmental Protection Agency (EPA) must meet in the development of regulations for the foam industry, and to discuss how the EPA is meeting these requirements. The EPA and the PFA have worked together to ensure that any EPA decisions are based on the best available data. At this point, the primary information gathering efforts are complete, and the EPA is now in the process of analyzing the information and developing the regulation. This paper should provide a basic understanding of the ongoing and upcoming activities, so that EPA/Industry interaction can continue to be beneficial and effective.

This paper is separated into four sections. The first presents a brief overview of relevant Clean Air Act (CAA) requirements, as well as a description of general EPA actions in response to these requirements. The second section presents a basic review of the activities that have taken place to obtain information related to the foam industry. The third section discusses the application of the CAA requirements to the foam industry, using the information obtained. This section also provides some of the preliminary results of these analyses. The final section discusses upcoming activity for the development of the regulation.

S95002 Overview on the Concerns Facing Foam Fabricators from an Adhesive Supplier Standpoint, William Hazelgrove, Imperial Adhesives

 

 

For years the adhesive industry has been driven by the principal of the best product for the job, with efficiency being the key measurement of success. Now environmental compliance must also be considered. Compliance is more than just meeting a standard. It involves a completed change of process and technology which affects the choice of equipment and attitudes of employees. Adhesive formulations are changing daily to meet requirements of government agencies (OSHA and EPA).

 

This paper presents an overview of the changes brought about as a result of implementation of the Clean Air Act, and the subsequent elimination of 1, 1, 1, Trichloroethane and methylene chloride as solvents for adhesives are examined, and the advantages and disadvantages of each are reported. The author feels that none of the alternatives (water based, hot melt, and flammable solvent) can be used without making modifications to process or operations.

 

S95004 Phase 1, UFAC Open Flame Tests, Hugh Talley, The Hugh Talley Company

A test protocol involving 15 different fabrics was developed to determine if there was adequate technical justification to add TB-117 foam to the UFAC voluntary program. The fabrics represented a cross section of those currently being used in residential furniture. Cushions were made using TB-117 type polyurethane foam, conventional polyurethane foam, and polyester fiber wrap between the fabric cover and the foam cores. The ignition and flame spread characteristics of each sample was determined and visual comparisons of the burning characteristics of the flame retarded vs. non flame retarded conventional foam were made.

 Small open flame testing and cigarette ignition testing were performed separately on each type cushion construction. The tests were designed to simulate a carelessly dropped match on the top of a cushion, or the careless dropping of four cigarettes on the top of a cushion. A methenamine pill was used as the small open flame source, and a Pall Mall cigarette was used for the standard UFAC testing.

The conclusion drawn from the cigarette ignition testing was that the TB-117 foam made no difference or improvement in cigarette ignition propensity.

The conclusions drawn from the small open flame testing were:

  • The TB-117 foam made no significant, consistent difference in either ignition or flame spread.
  • These tests demonstrated that changes in construction to improve small open flame performance can negatively affect performance in cigarette ignition.
  • The use of polyester fiber wrap topper pads had no significant qualitative effect on small open flame ignition or flame spread.
S95006 The Recyclability of Polyester Fiber and Flexible Polyurethane, David Gibala, ARCO Chemical Co.

Material reuse, through transformation or by lifetime extension, is at the center of the recyclability debate. The transformation of thermosets, such as polyurethane foam, for reuse is a widespread industry, although, to date little has been led to believe that thermoplastics can be decomposed and reconstituted ad infinitum.

The objective of this paper is to focus attention on the factual side of thermoset versus thermoplastics recyclability debate.

Comparisons of flexible polyurethanes and polyester fiber for furniture and automotive seating applications are used to illustrate that little practical difference (indeed urethane offers more options) exists concerning the recyclability of these materials. Product lifetime must, therefore, remain the main criteria in material selection.

In broad terms, it may be seen that both polyurethane and polyester fiber are recyclable using mechanical, chemical, thermal, and catalytic cracking options. The point to note is that more technological options exist for polyurethanes.

From the information given in this paper, it is clear that both mechanical and chemical recycling of thermosets and thermoplastics is a reality today, and that options clearly exist for the future.

With regard to automotive seating, polyurethanes currently offer more technological options and outlets to both original and new applications. The latter is illustrated through the range of uses for rebonded foam. Mechanical recycling of polyester fiber appears to be limited in scope and application of the resulting materials.

Chemical recycling of polyester fiber might suffer processing limitations because relatively clean bottle scrap would be contaminated by a small and potentially heavily contaminated stream of fibers.

Environmental issues aside, information gathered to date clearly shows that polyester fiber for seating applications does not match polyurethane in cost and durability

S95008 Enhanced Wear and Appearance Retention of Carpet When Cushion is Used, William Wald, Technical Director, Carpet Cushion Council

The author reviews recent studies on the positive effects of cushion on carpet appearance. One of the most persuasive studies, done in Canada by Dr. Charles Huskilson of Dupont in the mid eighties, examines the Hexapod Drum for carpet wear and appearance testing. Six different carpet constructions were evaluated on four different machines at three different labs with and without cushion. The results, which were correlated with walk-on tests, showed cushion always improved carpet appearance.

The author undertook a similar program to more sharply identify the benefits of carpet cushion. Using the Vetterman drum test, carpet with and without cushion, was examined using carpet which had shown excellent correlation between drum tests and walk on exposure. Again, using a variety of assemblies, cushion always improved carpet appearance.

Walk-on tests were started on March 20, 1995 at Southern College of Technology in Marietta, GA to obtain a direct correlation between Drum tests and “real world” performance. The tests were patterned after PFA’s Residential Walk-On Tests except that a complete spectrum of cushions were evaluated rather than the limited number normally run.

The carpets were evaluated after 50,000 traffics and again at 84,000 traffics. All cushioned areas, except one, showed improved appearance over the uncushioned blank areas. Reproducibility of the test was very good throughout.

Future plans are to continue the test, reconvening and recording results at 50,000 step intervals.

Proceedings of the Polyurethane Foam Association Technical Program
October 1994

F94001 Reduction of Volatiles in Polyester Based Flexible Foams, D.J. Grillo, T.L. Housel, and F. A. Landis, Inolex Chemical Company

Flexible polyurethane foams are found in a wide variety of applications throughout the world. These applications include automotive components, furniture, carpet underlay, textile products and packaging. Certain varieties of flexible foam have been found to slowly emit volatile substances. Some of these volatile substances are non-reactive materials which are contained in the ingredients used for flexible foam manufacture.

The intent of this work is to review research and development of polyester polyols which can reduce the emission of volatile materials from the finished flexible foam as well as during the manufacture of the foam. Three specific areas are addressed. They are poly (diethylene glycol adipates) for low volatile foam, internally catalyzed polyester polyols to reduce catalyst emissions and odor during manufacture, and reduced volatility polyester polyols for reactive diluent carrier systems.

Polyethers are the dominant polyol class used to manufacture flexible polyurethane foam. However, polyester polyols are an important component of certain flexible foams used in automotive interiors. Flexible foams based upon poly (diethylene glycol adipates) have been investigated for volatile substances which have been found to fog automotive windshields. These substances have been identified as cyclic esters of diethylene glycol adipates (cyclic DEG adipates). Commercial scale manufacturing processes have been shown to reduce these cyclic esters by over 75%.

Catalysts, surfactants, colorants, and other additives are used in the manufacture of flexible polyurethane foam. Some of these additives are dispersed in a low molecular weight poly (diethylene glycol adipates) carrier which is used as a reactive delivery vehicle which will not compromise foam quality. A reduced volatility grade of this polyester has been commercially produced.

Certain amine catalysts create odors which can affect foam manufacturing workers, and necessitate additional emission controls. Internally catalyzed polyester polyols, which obviate the need for volatile amine catalysts, have been explored. Through the development of all of the above polyester polyols, the authors hope to present viable alternatives for reducing emissions from flexible foam.

F94003 The Fire Safe Cigarette Act of 1990, An Assessment of Results, R.G. Gann, Chief, Fire Science Division, Building and Fire Research Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899

Cigarette ignition of soft furnishings (upholstered furniture and mattresses) continues to be the leading cause of fire deaths in the United States. As a means to accelerate reducing these losses, the Cigarette Safety Act of 1984 (Public Law 98-567) had created a Technical Study Group on Cigarette and Little Cigar Fire Safety (the TSG). The purpose of this group was to “undertake such studies and other activities as it considers necessary and appropriate to determine the technical and commercial feasibility, economic impact, and other consequences of developing cigarettes and little cigars that will have a minimum propensity to ignite upholstered furniture or mattresses.”

In its final report the TSG concluded that “it is technically feasible and may be commercially feasible to develop cigarettes that will have a significantly reduced propensity to ignite upholstered furniture or mattresses. Furthermore, the overall impact on other aspects of the United States society and economy may be minimal. Thus, it may be possible to solve the problem at costs that are less than the potential benefits, assuming the commercial feasibility of the modified cigarettes. 

A valid and reliable test method is needed to assess the commercial feasibility of the modified cigarettes. None of the several alternative test methods for measuring the cigarette ignition propensity of soft furnishings is usable in its current state of development.

This paper summarizes the results of the work performed under the Cigarette Safety Act. Copies of the technical reports can be obtained from the Consumer Product Safety Commission.

 

F94005 Advanced Polymeric Colorant Technology in Bonded Foams, J.D. Cobb III, M.E. Ragsdate, Milliken Chemical, Spartanburg, SC

Milliken Chemical offers a polymeric colorant technology specifically designed to meet the needs of today and of the future of the bonded carpet underlay market. This new polymeric colorant technology is helping to transform the manufacturing and marketing of bonded carpet underlay. Milliken Chemical is well known in the industry for its Reactant® color technology used in prime flexible foam.

Using similar technology, Milliken has introduced a line of colorants specifically for the bonded underlay market. This technology is called Bond Tint® Colorants. They are reactive polymeric colorants specifically designed for coloring polyurethane adhesive used in manufacturing bonded carpet underlay. In comparison to conventional pigment dispersions, Bond Tint® colorants and metering systems are a superior means by which to color bonded underlay.

 

F94007 An Assessment of the Impact of the EPA Risk Management Program on the Polyurethane Foam Industry, George Rusk, Tom Ferrara, Ecology & Environment

The EPA has been involved with the polyurethane foam industry for many years. The EPA manages air permits and models, risk management plans, environmental impact assessment, site investigation sampling, audits and compliance, as well as training. With the aid of EPA, industry manufacturers can perform hazard assessments and develop accident prevention programs. Emergency response programs are also crucial. This presentation outlines each area of concern with various options and approaches.

The paper concludes that it is necessary for foamers to eliminate chlorinated solvents and other types auxiliary blowing agents from their production.

Also included is a case study entitled, “Application of California’s Risk Management & Prevention Program (RMPP) to comply with EPA’s upcoming risk management program (RMP) Rule” by Phuoc Le of the Science Applications International Corporation (SAIC). This report is followed by “EPA Risk Management Planning” by Peter McKnight of the SAIC. Attached to the paper is an addendum entitled, “Latest Manufacturing Solutions for Slabstock Foams” supplied by the Cannon group.

 

F94009 Latest Manufacturing Solutions for Slabstock Foams, C. Fiorentini, M. Taverna, B. Collins, C. Greaves, T. Griffiths, Cannon Viking

As environmental pressure increases worldwide, it is becoming necessary for foamers to eliminate chlorinated solvents or any type of auxiliary blowing agents from their production. In some countries these solvents have already been banned. The impact on the flexible foam industry would be to increase foam prices, and to eliminate certain soft grades of foam.

The Cannon Group has developed a new process for introducing liquid CO2 into slabstock polyols, and successfully produce low density foams on modified slabstock equipment.

This revolutionary process, for which patents are pending, is named CarDio™, from Carbon Dioxide. The process enables foamers to continue producing their existing foam grades at a lower chemical cost due to the significant price differential between CFC’s, ABA’s and CO2.

A plant was built in the Cannon R&D Facility in Milan, Italy, to develop CO2 blown slabstock foam. Following the successes with the pilot plant, the first industrial plant was installed in March of 1994 in Italy near Venice.

 

 

F94002 Advances in Catalysts for All Water Blown Flexible Slabstock Foams, T. W. Bodnar, J.D. Nichols, K.D. Wiese, Air Products and Chemicals, Inc.

Recent changes in the status of traditional blowing agents have left many flexible foam producers searching for new technology. There are a number of methods available to modify the foaming process and circumvent the need for physical co-blowing agents.

One method currently gaining popular support is the concept of forced cooling. This process modifies the curing cycle of freshly prepared foam blocks and enables the use of high water levels for blowing without the usual concerns of excessive exotherm.

The process to force cool a piece of foam is simple in principle. The challenge lies in preventing the shortened cure time from interfering with the development of the polyurethane/urea polymer network, which could result in the loss of critical physical properties. To overcome these obstacles, Air Products and Chemicals, Inc., has developed a new catalyst, Dabco® H1075, with performance characteristics matching the requirements of forced cooled systems. Benefits include the ability to maximize the rate of and ultimate isocyanate conversion, providing greater overall polymer strength. Through the manipulation of isocyanate index and water level, a complete range of foams can be produced using Dabco H1075 in forced cooled systems. Additionally, Dabco® H1075 has significantly reduced odor as compared to more conventional amine catalysts.

A second approach to eliminating the use of alternate blowing agents has been the development of a variety of foam softeners and/or modifiers which enable the use of water as the sole blowing agent to produce most foam grades. While foam softeners are used to reduce the hardness of foams blown with high levels of water, foam modifiers improve foam stability allowing a reduction in TDI index to indirectly provide softening through hard segment reduction. With either of these approaches, however, additional additive(s) must be incorporated into the foam formulation.

As an alternate means of altering foam morphology to decrease the hardness of all-water blown foams, Air Products has developed an experimental tin catalyst, XF-J140, for flexible foam formulations. This new catalyst provides processing performance similar to stannous octoate based materials, but produces significant softening in many grades of all-water blown flexible slabstock, without the need for additional additives.

The performance characteristics of both new catalysts are presented in this paper.

 

F94004 Computer Control of Foam Production, Property Prediction Models for Conventional and High Resilience Polyurethane Slabstock Foams, R. Schiffauer, Arco Chemical Co. South Charleston, WV

Flexible polyurethane foams of all types are a unique group of plastic materials, characterized by the fact that a multitude of different sets of properties can be obtained by varying the levels of small number of base components in the formulations. As a result flexible polyurethane foams have always been suitable candidates for correlating these variations in the formulations with the resulting properties in a mathematical way. The ultimate gaol is to predict these properties as accurately as possible, fine tune existing grades and design new foam grades. Several such models have been previously reported.

This paper extends the models for conventional flexible slabstock foams beyond the previously reported key properties of density, hardness and fatigue to other important properties such as elongation, tear strength, tensile strength, set properties, and foam exothermic temperature. Also, included are variables such as low TDI index and low index stabilizers, which show complex correlations including several interaction terms.

The second part of this paper discusses the influences of the specific variable for high resilience slabstock foams on a similar set of properties. Apart form the variables common to both HR and conventional foam, namely water level, TDI index and polymer solids, particular emphasis is placed on he effect of diethanolamine, as well as highlighting the inherent differences in hardness between the two types of foam.

This paper describes the use of these models to either calculate properties from formulations, or alternatively, to calculate formulations for given set of properties, as well as mathematical and computer techniques to perform these calculations.

F94006 Introducing Foam Flush™ Urethane Remover - The Cure For Urethane Cleanup, V.T. Roberts, International Specialty Products

 

This paper covers a new program for replacing methylene chloride for cleaning polyurethane production equipment for the manufacture of flexible and rigid foams as well as for the manufacture of coatings, adhesives, sealants and elastomers. The regulatory issues surrounding methylene chloride are the driving force behind the search for alternatives.

Foam Flush™ is more aggressive than methylene chloride, provides residue free cleaning, contains no water or other ingredients which can interfere with the foaming chemical reactions, and has the benefits of being safer in the workplace and friendlier to the environment. It is more efficient than methylene chloride because, having a very low evaporation rate, it clings to work surfaces and continues to penetrate long after methylene chloride has evaporated.

Foam Flush™ is a very active solvent, consequently, gaskets, seals and hoses must be checked for compatibility. Materials such as Viton®, PVC, ABS, Kynar®, Lucite®, Noryl® 731, Ultem®, and Buna-N are not acceptable. TeflonR®, Nylon101, butyl rubber, silicon rubber, polyamide, high density polyethylene and polypropylene are resistant.

Since this product is an active solvent for oils and greases, it will rapidly defat the skin. Therefore, the hands, face and eyes must be protected, as in the case in handling all urethane intermediates.

 

F94008 Benchmarking - Automotive Seat Cushioning Materials, I.L. Huges, The Woodbridge Group

 Automotive seat cushioning material provides a multitude of functions in a well designed, stylish, comfortable and durable seat assembly. The purpose of this study is to evaluate a variety of current production as well as proposed cushioning materials with respect to their ability to produce a “best-in-class” automotive seat. The Woodbridge Group’s evaluation provides a technical comparison of measurable properties of a common seat style with respect to the seat cushioning materials functional qualities.

Tests performed and reported in this paper are restricted to items which have a definite bearing on seat appearance, performance, comfort, and durability, and can be numerically compared to the automotive seat industry established specifications and acceptance criteria.

The seat style used in this evaluation is a 1994 Chevrolet Caprice drivers bucket seat with cushion pads manufactured from molded polyurethane foam, molded polyurethane foam with high levels of automotive recycled content (Woodbridge Ecostream™), molded polyester fiber, and molded rubberized natural fiber with animal hair.

 

 

Proceedings of the Polyurethane Foam Association Technical Program
May 1994

S94001 Initial Test Programs-Comparison of Flexible PUF and Polyester Fiber Seat Cushions, Tom Murphy, Flexible Foam Commercial Committee of SPI

The objective of this program is to define the benefits of flexible foam vs. polyester fiber in cushioning applications. The critical issues affecting the growth of flexible foam are addressed, and data is provided to PFA to compete in the marketplace.

The impacted markets are: The Flexible Molded Foam and Flexible Slabstock Foam Markets. The molded market consists principally of automotive seating , and the slabstock market of furniture bedding.

Data is provided on the loss in thickness of covered cushions made with flexible foam vs. identical cushions made with polyester fiber using an Iso Pounding test procedure. Fatigue data on fiber wrapped foam cushions using the same Iso Pounding test is also shown.

Durability and performance testing is underway at Woodbridge Foam on a parallel program for Automotive, and data will be shared with the joint PFA/FFCC Task Force. Additional testing is scheduled to begin the second quarter of 1994 on automotive seat foam using an actual GM seat part.

 

 

S94003 Next Generation Geolite® Modifier Technology, B.L. Hilker and L.F. Lawler, OSI Specialties, Inc.

Advances in the next generation Geolite® modifier additive technology for slabstock foam are discussed. Recent progress has identified stabilizing additives which allow foam to be produced using isocyanate indexes as low as 85 with improved properties over those previously obtained. Such low index formulations involve increased water levels and allow for the production of soft foam grades with significantly reduced levels of auxiliary blowing agents. All-water blown foams having densities as low as 1.0 pcf. have been produced with this technology with acceptable exotherms. While some low density foam grade properties are not yet optimum, all seating grades of foam, possessing good properties and no discoloration, can be made with this technology.

New Geolite® modifier additives significantly improve foam property limitations induced by mechanical cooling technologies, especially compression sets. Recent findings also revealed similar compression set benefits using the new Geolite® modifier additives in flame retardant foams.

S94005 IFD Test Protocol Intralaboratory Statistical Study, Audie Mitcham, Drexel Heritage Furnishings, Inc.

The objective of this study was to determine the precision of IFD measurement for upholstered furniture seating cushions. The test protocol which was used was ASTM D 3574-86, Test B 1, “Standard Methods of Testing Flexible Cellular Materials-Slab, Bonded, and Molded Urethane Foams.” Nineteen laboratories participated. Each laboratory received a calibration spring for initial equipment and procedural evaluation. Each laboratory also received three foam samples from each of two sample sets. All foam samples were screened at BASF laboratories for sample consistency.

The following data was obtained on the test samples: height, weight, 25% IFD, 65% IFD, 25% return IFD, test area temperature and relative humidity, and equipment type and capacity.

The following conclusions were derived from this study: Interlaboratry Precision of the test method, or h Value, indicated relatively consistent performance between laboratories. Each laboratory only has an approximate 5% effect on the whole due to the dilution of results by 19 labs.

Reproducibility of the test method within laboratories, or k Value, showed that a number of laboratories have a need for improvement on equipment or measurement scale. This data also showed an increased number of labs exhibiting imprecision of data as load on their IFD machines increases to perform the 65% IFD tests.

S94007 A Study of the Dynamics of Liquid Movement in a Max-Foam Trough, R.D. Duffy, Arco Chemical Co.

ARCO Chemical company has sponsored a study of the dynamics of the movement of polyurethane foam chemicals through Max-Foam trough. The purpose of the study was to determine the effect of trough inlet configuration and trough shape upon the occurrence and position of deformities or non-uniformity of physical properties in Max-Foam blocks. To date, this investigation has provided numerous novel results and observations.

The results of the study show that the dual inlet trough concept may be linked to many slab foam production difficulties. Observations made during the study show a single trough inlet and a tapered trough shape greatly enhance the age consistency of the single trough inlet and a tapered trough shape result in improved foam yield during on-the-fly formulation/grade changes by reducing the grade transition time.

The equipment used for this investigation consisted of an experimental see-through, glass-backed trough. The ability to view the entire cross-section width and height of the foam machine trough afforded the opportunity to study the intra-trough dynamics in a most thorough manner. The turbulent moving action of the chemical mixture throughout the trough was not the expected movement. Based on these observations, the authors were able to develop improved trough configurations. All the slab foam production machines utilized in the see-through trough evaluations were high pressure/low shear Max-Foam machines.

The foam grades evaluated during the see-through trough studies included the full range of foams normally offered by polyether slab foam producers. They included such diverse foams as filled foams, high load bearing foams, super soft foams, and sponge foams.

The new trough design resulted in the following benefits:

  • Reduced foam loss as a result of foam grade changes
  • Improved uniformity in the age of chemical composition exiting the trough
  • Improved side to side foam reaction/gelation characteristics
  • Reduced tendency for side channeling when using a Rectangular Section flat-topping mechanical unit
  • No detrimental effects on foam production or foam physical properties were observed as a result of using the modified single inlet trough design
S94009 Controlled Environmental Foaming - Manufacturing a New Generation of Polyurethane Foam, Scott Carson, Foam One

As environmental and competitive economic factors increase worldwide, every industry is faced with the challenge of continually improving its products and manufacturing methods. Foam One has developed and patented a polyurethane foam manufacturing process called Controlled Environment Foaming (CEF), that allows the foam industry to meet these challenges in a manner that is socially acceptable for the environment and profitable for the industry. The Foam One CEF process is a discrete block production method, which uses a containment vessel to control the pressure and temperature during foaming, and uses scrubbers to properly treat all emissions.

The Foam One CEF process allows for the production of all grades of foam presently marketed as well as giving the foam manufacturer the ability to produce new foam products. The first full-scale machine utilizing the Foam One CEF process is now operational and has shown that these goals have been accomplished. The technology for this process is being licensed by Foam One, and the machinery is being built and sold by Edge Sweets Co. of Grand Rapids, Michigan.

The Foam One CEF principle of operation is that a formulation can be processed at less than atmospheric pressure, i.e., under vacuum, to produce a lower density and softer foam compared to the same formulation processed at atmospheric pressure. Likewise, if this same formula is processed at a pressure greater than atmospheric pressure, a higher density firmer foam is obtained. By using pressures, either above or below atmospheric pressure, the Foam One CEF process achieves the goal of being able to make foam products, which are not currently being manufactured.

The use of pressures below atmospheric allows the industry to manufacture very soft foams with out the need for blowing agents such as CEC’s, methylene chloride, or trichloroethane, The use of pressures greater than atmospheric pressure increases the urea content of the foam, which allows the industry to manufacture very firm foams with out the need for expensive polymer polyols. Since the process occurs in a contained environment, it is very easy to capture and scrub any objectionable emissions that occur during production. The discrete method of production is used in the Foam One CEF process because it offers a system that permits the efficient manufacture of foam at a modest capital investment in machinery.

The polyester batting or polyester fiber cushioning market, which was previously closed to polyurethane foam due to its higher cost, is now available to polyurethane foam. Polyurethane foams with physical properties equivalent to premium batting has been produced using the Foam One CEF process. This market is about 400 million pounds per year and growing.

In conclusion, the Foam One CEF Process offers the polyurethane foam industry a new approach to meeting the concerns presented by environmental and competitive economic factors.

 

S94002 Report on the Foam Adhesive Ventilation Project, Steve Risotto, Center for Emissions Control

The author presents an overview of the use of solvents in foam fabrication operations, and presents data on worker exposure to methylene chloride fumes in various fabrication operations. Recommendations are made for modifications to ventilation systems to reduce worker exposure to fumes. A list of the disadvantages of water based adhesives is also given.

 

S94004 New Trends in the Polyol Stabilization Technology, Robert L. Gray, Robert E. Lee, and Richard S. Rose, Great Lakes Chemical Corporation

Changes in the flexible slabstock industry such as replacement of chlorofluorocarbon (CFC) blowing agents have placed new demands on the stabilization packages used in this application. The use of higher levels of water to induce carbon dioxide formation and release, result in a significant generation of additional heat. In inadequately stabilized foams, this can lead to scorch and potentially self-ignition.

Butylated hydroxytoluene (BHT) has been the traditional foundation of the stabilization package. Phenolic antioxidants are used to protect the polyol from oxidation during manufacture, minimize hydroperoxide formation during storage and reduce scorch during PUR foam manufacture. The relatively high volatility of BHT is a concern as it is easily volatilized out of the foam during the foam processing, and can cause problems with BHT build-up. Additionally, BHT is also known to cause staining.

A variety of structurally dissimilar phenolic antioxidants were evaluated for performance as scorch inhibitors. The results of screening work indicated that all of the antioxidants evaluated provided a high level of scorch protection. The reactive performance is as follows: Anox PP 18 > BHT > Anox 20 > DBNP The traditional Antioxidant BHT was among the best performers. Foams prepared with DBNP showed a slightly higher level of discoloration as compared to BHT. This small difference in performance may be structurally related.

Volatility of the antioxidants as measured by thermogravimetric analysis (TGA) shows that BHT is the most volatile. It showed a 5% weight loss at about 90°C, and a 90% loss at about 142°C. DBNP has a range for the 5% and 90% weight losses of 120°C to 182°C respectively.

The proprietary product AS-1, Anox PP-18 and Anox 20 have TGA volatility values that are predominantly above the peak exotherm temperature of flexible slabstock polyurethane foam. They would be expected to volatilize significantly less during foam cure. The decreased volatility is achieved by increasing the molecular weight of the antioxidant by the addition of long hydrocarbon chains to the molecule.

The authors have concluded that the requirements of polyurethane slabstock foam manufacturers vary due to sensitivity to antioxidant volatility, preference in physical form (liquid or solid), and degree of anti-scorch protection. As a result of this broad variation in antioxidant performance demands, several alternative antioxidants to BHT have been presented. DBNP and a developmental product, AS-1, combine relatively low volatility and good anti-scorch performance with the advantage of a liquid product form. Anox PP 14 and Anox 20 have significantly lower volatility than BHT and improved performance.

S94006 Safety Standards for Foam Fabricating, Dario Ramazzotti, Edge Sweets

 The objective of this paper is to introduce a proposed American National Standard Safety Requirement for the manufacture, care, and use of machines to cut, slit or buff plastic foams and related materials. The purpose of the standard is to minimize hazards associated with machine activity by establishing requirements for the manufacture, care, and use of these machines. The project was initiated under the auspices of the Polyurethane Foam Association and the Safety Committee of the Machinery Division of the Society of the Plastics Industry, Inc.

 An ad hoc committee, composed of representatives from Baumer of America, Inc., Edge Sweets Co., Fechen-Kirfel America, Inc., and Ferry Industries (Femco), was formed to develop this standard, and it has been distributed to the industry for review. The standard will then be submitted to a broader review group through the SPI prior to submission to ANSI. If the standard is accepted by ANSI, then it will become law as a subdivision of OSHA.

S94008 Recycle/Recovery - Challenge or Opportunity, Chip Sweet, Dow Chemical Co.

The Polyurethanes Recycle and Recovery Council (PURRC), a unit of the Polyurethane Division of The Society of the Plastics Industry Inc., comprises the cooperative efforts of 15 member companies. PURRC was formed in 1990 to catalyze and facilitate the recycling of polyurethanes. To date, PURRC projects have identified potential sources of recyclable polyurethane scrap, determined the available quantities and quality of select large volumes, researched recycle/recovery processes and further developed promising options. In addition, actions of other organizations both governmental and in the private sector are monitored.

Several regulatory initiatives have been taken or are under consideration to limit, divert or prohibit the disposal of polyurethane containing waste. Other proposals would require recycle content of up to 50% for some plastic materials. These initiatives represent a growing trend to control waste materials that could affect the economic viability of polyurethane businesses, or force manufacturers and customers to choose alternate materials.

The PURRC Flexible Foam Task Group continues to investigate several projects with the potential to dramatically increase the demand for scrap foam. Summaries of the current PURRC projects are presented in this paper. A discussion of the PURRC project to add ground polyurethane foam scrap to the production of slabstock foam is also presented.

Recycle/Recovery, the issue of the 90’s, presents a “mixed bag” to the polyurethanes industry. Bonded foam is a demonstrated success. Immediate pressure for recycle is primarily focused in the automotive sector. The increasing collection of post-consumer scrap can replace the inconsistent overseas supply, but, will the scrap supply exactly balance with demand? Can more bonded scrap be used in the bonded process or can more non-bonded scrap be collected? If not in balance, will the value of scrap follow the experience of the other large recycled materials like paper, aluminum cans, glass and decline? Can other uses of scrap be developed? What will be required to supply the automotive industry or the Federal Government? These are some of the issues and questions that coupled with the approach taken by the flexible polyurethane foam industry will determine whether recycle/recovery is an opportunity or challenge.

 

Proceedings of the Polyurethane Foam Association Technical Program
September 1993

F93001 New Ultrasoft Low Density Foams as Alternatives to Fiber Batting, S. L. Hager and R. D. Duffy, Arco Chemical Co.

Polyurethane foam and polyester batting are cushioning materials that have found widespread use in a variety of applications. In some cases they compete for the same market, in others they are used together in a complementary fashion, while in still others one or the other is dominant for performance or cost reasons. Foam has tended to be the dominant material in those applications requiring higher load bearing and/or long term durability such as cushion cores, carpet pad and mattress toppers. Fiber batting has intended to dominate lighter duty applications requiring high filling efficiency or a very soft surface such as comforters, toys, loose backs and cushion wraps.

A new foam formulating technology is introduced in this paper, Softcel™ foam, that allows the production of ultrasoft low density polyurethane foam having cushioning characteristics closer to that of fiber while maintaining the durability and other performance characteristics of foam. This new foam is a major extension of the Ultracel® slabstock technology. A variety of slabstock grades have been produced on either full scale or pilot scale machines. The full grade range possible with this technology using auxiliary blowing agents is expected to run from below 1.0 pcf to 1.8 pcf with IFDs ranging from about 5 to 20. Auxiliary blowing agent requirements to soften the foam are substantially less than for conventional foam and can be totally avoided in many grades. The limited data available at this time indicates that these foams perform well in small scale ignition and smolder resistance tests such as CAL TB117 and the UFAC Barrier Test. Comforters produced with low density soft foam grades have exhibited feel and drape comparable to fiberfil but with improved durability.

F93003 California TB - 133 - The Nemschoff Approach, Mark Nemschoff, Nemschoff Chairs

This presentation discusses FR compliance misconceptions dealing with issues such as how FR additives affect furniture cost, lead time for furniture production, furniture durability, and product warranties. A case is made for Calif. TB 133 compliance.

Various research strategies to determine code compliance are provided. Techniques for creating Calif. TB 113 compliant furnishings are also explained.

F93005 Predictions of TDI Emissions from Flexible Foam Production Line, H. Metcalf, F. Sweet, Dow Chemical USA

Governmental regulation (federal, state, and local) of industrial emissions is expected to increase over the next few years. Regulations relating to the control of or tax on emissions of TDI from flexible slabstock polyurethane foam production lines, are possible. As a result, it has become increasingly attractive, if not necessary, to develop a method for predicting TDI emissions from the exhaust stacks for such facilities. Data from seven full-scale production facility emission surveys were entered into a database and analyzed per statistical method techniques.

The data included information on foam grade and formulation, component flow rates, run times, ambient conditions, and TDI emission levels. The 2,4- and 2,6- TDI emissions were measured from the pour line exhaust stacks by The Dow Chemical Company Health and Environmental Sciences personnel, utilizing EPA recognized methods.Two preliminary mathematical models have been developed to calculate the expected TDI emissions based on foam formulation, plant and ambient condition information. The resulting models allow a foam production facility to predict the total 2,4- and 2,6- TDI emissions from a given set of foam formulations using ambient condition information for the day on which the foam is produced.

 

F93007 Auxiliary Blowing Agent Substitution in Slabstock Foams, C. Fiorentini, Cannon Group, T. Griffiths, TG Cellsoft Ltd., M. Taverna, Cannon Group, B. Collins, Cannon USA

As the pressure to eliminate chlorinated products such as Chlorofluorocarbons, methylene chloride, 1,1,1,-trichloroethane etc. (CFC’s) from the environment increases worldwide, it is becoming necessary to eliminate them from polyurethane foam production. These additives have already been banned in some countries. The impact on the flexible foam industry would be to increase foam prices and to eliminate certain soft grades.

The use of liquid carbon dioxide (CO-2) as an auxiliary blowing agent in a polyurethane foam is a good and well accepted idea. Handling this liquid, which is a gas at room temperature, has always been one of its main problems.

Cannon has developed a new process for manufacturing flexible slabstock foams without the use of CFC’s. This revolutionary new process called CarDio® (from carbon dioxide), has been able to completely eliminate the use of CFC’s and other volatile Organic compounds (VOC’s) from flexible foam slabstock production. This has been done without sacrificing the foam’s physical mechanical properties. The CarDio process also dramatically reduces the size requirements for foaming plants, thereby allowing all the advantages derived from a reduced floor space and plant volume. Flexible slabstock foamers are able to continue producing their existing foam grades at a lower chemical cost due to the significant price differential between CFCs, ABAs, and carbon dioxide. Patents have been applied for the process

F93009 Variable Pressure Foaming - A New Generation Foaming Technology, R. Triolo, Foamex

A new commercial process for foaming under variable pressure has been developed. The process offers numerous advantages, the first of which is that no auxiliary blowing agents are necessary to produce lower density foams. The formulation advantages now make density virtually independent of water concentration and auxiliary blowing agents. Foams can also be produced with high load bearing without the use of polymer polyols.

Commercial experience with the system has demonstrated that the foams exhibit superior physical properties. The resulting foam is more open, has better resilience, superior compression set, and better mechanical properties. There is also greater control over the density and hardness variation from run to run. The process is fully automated, offering superior control over the final product. The environmental advantages of the new system are that no auxiliary blowing agents are used, the reaction gases are treated before exhaust, and there are no isocyanate vapors in the production area.

F93002 Texaco Chemical Company, Propylene Oxide Business Entry, J. Lemonds, Texaco Chemical

This paper introduces Texaco Chemical Company’s entry into the propylene oxide business with a new world class facility presently being constructed at their flagship Neches Chemical Plant in Jefferson County, Texas. Propylene oxide is the building block chemical from which polyether polyols are made.

Propylene oxide design capacity is 400 million pounds per year. Coproduct MTBE is 1.3 billion pounds, or 15,000 barrels per day in motor gasoline terms. Total capitol for this project, including working capital, exceeds five hundred million dollars. Mechanical completion is expected in the third quarter of 1994.

 

F93004 California Technical Bulletin 117 Revisited, S. E. Wujcik, T. M. Smiencinski, R. F. Pask, BASF Corporation

During the past 20 years, more than 30 flame tests have been developed. These range from a simple measure of the amount of oxygen needed to support combustion to full scale furniture burns under controlled conditions. The California TB 117 flame test, by far, is the most frequently run standard furniture flame test. It has been around for more than ten years. 

The requirements for passing TB 117 are fairly easy to meet. The addition of a small amount of a chemical, usually a halogenated phosphate flame retardant metered in during foaming, is all that is required. Most of these chemicals have little effect on the foam process or the foam grades produced. More recent flame tests, such as BS-5852, Part II, Crib 5 or CAL TB 133 are much more involved. In order to pass these tests it is necessary to make significant changes in equipment and the chemical formulas.

This paper describes the scope of the California TB 117 flame test along with a procedure for Resilient Cellular Materials and formulations for producing flexible polyurethane foams.

F93006 The Use of Unilink 4200 in Flexible Polyester-Based Polyurethane Foams, D. W. House, R. V. Scott, Jr., United Oil Products

 Unilink® 4200, 4,4-bis-(secbutylamino) diphenylmethane, is a proprietary UOP additive that reacts in a urethane foam formulation to increase both the level of urea groups present and the hard segment content. As an aromatic secondary diamine, it reacts with the polyisocyanates to produce linear polymer chains. Although primary amines are known to react too rapidly for use in flexible foam formulations, the liquid Unilink 4200 has a reaction profile more similar to the polyol/isocyanate reaction.

Polyester-based urethane foams are typically chosen over polyether-based foams in applications requiring greater load-bearing, higher tensile strengths, and higher elongation. The use of Unilink 4200 in typical polyester-based formulations has led to even grater increases in these three important areas without increasing foam density. In general, the use of Unilink 4200 led to increases in load bearing of about 30% at 25% deflection and 40% at 65% deflection. Tensile strengths (both perpendicular and parallel to foam rise) increased significantly with Unilink 4200, and this increase was greater at higher densities. Elongation was only slightly improved at lower density; however, at 3.2 pcf (51kg/m(3)), the elongation was 45% greater perpendicular to foam rise and 58% greater parallel to foam rise.

Typically, efforts to increase tear strength in foams have usually been at the expense of other properties such as elongation. The use of 5 php of Unilink 4200 led to an average increase of over 40% throughout the entire density range studied, and did so without adversely affecting elongation. Though air flow was lower when Unilink 4200 was added to the formulation, there was no shrinkage of the uncrushed foam. All of these benefits have been obtained without increasing foam density above that of the control foams (without Unilink 4200).

In the present work, polyester foams representing densities ranging from 1.6 to 3.4 pcf (28 to 54 kg/m(3)) were studied as a function of density, blowing catalyst, surfactant, and Unilink 4200.

 

F93008 The Rapid Cure Process-Industrial Experience, Engineering and Formulation Principles, H. Stone, E. Reinink, S. Lichvar, W. Carlson, C. Sikorsky, General Foam

 

The concept of rapidly cooling freshly prepared flexible polyurethane foam in order to reduce space requirements and storage time in the plant has been recognized for a long time. Recently, growing concern about ozone depletion in the upper atmosphere, has led to a phase-out of chlorofluorocarbon blowing agents, and has placed new emphasis on developing alternative approaches for producing flexible slabstock foams.

The objective of the work, presented in this paper, is the development of a foaming process using only water as the source of gas for foam blowing. This approach presents two major problems. The first is the engineering problem of avoiding long exposures to the high temperatures encountered in using only water as the blowing agent, particularly for low density foams. The second is the problem of maintaining physical properties and performance for the full range of density and hardness grades of foam in industrial use.

The Rapid Cure Process basically consists of a series of cooling chambers over which the foam passes after completing its rise. At that time the hot gases as well as small amounts of volatile impurities are removed, and the foam is cooled to a safe temperature. The preferred cooling medium is air being drawn through the foam. The exhaust gases are treated in a carbon bed to remove trace impurities, including TDI, before they are discharged to the air.

One of the additional benefits of this process is a significant improvement in foam uniformity, particularly in uniformity of IFD throughout the foam block. Another is a general improvement in the plant atmosphere by elimination of trace contaminants in the air.

This paper describes equipment modifications for the full-scale foam production, and formulation developments, to optimize physical properties and processing, in the laboratory, pilot plant and on full-scale production runs.

After more than a year of commercial production experience with the Rapid Cure Process, General Foam has the ability to handle a variety of foam grades with little or no changes in physical properties from their previous standards. Engineering changes have also been introduced in the process to optimize performance.

 

 

F93010 The True Cost of Meeting California TB-133, H. Talley, The Hugh Talley Co.

 The costing of furniture products is a difficult task because of the style/fashion requirements and the need to remain competitive. Costs and cost ramifications are some of the least understood subjects in all areas of upholstered furniture. Both industry people and non-industry people have tried to use a simple percentage increase number to represent the cost increase of making all furniture, which passes TB-133. When using this approach, it must be remembered that the percentages must be accompanied by a great deal more information in order to be meaningful and useful

Examples are provided in this paper demonstrating the cost increases associated with making stacking chairs and sofas which pass the TB-133 Flammability Test. Information is presented on the effects of using different manufacturing possibilities such as types of barriers, fabrics, flame retardant foam, back coatings and other ways to meet TB-133, on the final cost of the furniture.

Proceedings of the Polyurethane Foam Association Technical Program
May 1993

S93001 Testing Furniture Composites for Flammability Using an Oxygen Index Calorimeter, D. B. Parrish & S. A. Browning, Dow Chemical

California, Illinois and Ohio have established the full scale TB-133 flammability test for public occupancy furniture under their jurisdictions. This regulation is also under consideration by several other states. A search was initiated for a small-scale flammability test which would permit furniture manufacturers to pre-screen candidate cushion materials prior to submitting their proposed products to the expense of full-scale testing.

 The Oxygen Index Calorimeter (OIC), under development at the Dow Chemical Co., as a predictive small-scale flammability test, is introduced in this paper. It is presently intended as a low cost instrument for predicting the flammability performance of upholstered cushions for use in public occupancies. A description of the instrument calibration procedures for obtaining heat release numbers, and data from a number of cushion composite burns are provided. A number of full-scale mock-ups, burned at a single TB-133 burn facility, provided a means for comparing results from an Oxygen Index Calorimeter, The Cone Calorimeter, and the Ohio State University (OSU) Heat of Release Apparatus.

S93003 Models for Foam Formulating, Lee F. Lawler, Arco Chemical Co.

The properties of all water blown conventional polyether polyurethane foams are controlled by formulation and processing conditions, more so than individual component properties. For good quality, high air flow cushioning grades, used for furniture bedding or carpet pad, catalyst and surfactant effects are generally small. Therefore, only the major effects of water, index, and polymer solids need be considered. The term “polymer solids” is used interchangeably with “parts of polymer polyol” even though these two items differ by a constant factor. Processing conditions include those which impact foam breathability, structure and cell count.

The critical properties of foams are density and IFD. The general rule of thumb is that as water increases (density decreases) IFD decreases. This phenomenon is dependent on the amount of polymer polyol used and the actual amount of water in the formulation, i.e. foam density. At densities corresponding to between 2.5 and 4.0 php water, IFD increases with increasing water. If more than about 30 Parts of high solids polymer polyol, like Arcol® HS-100 is used, foam firmness always decreases with increasing water.

This paper quantifies the effects associated with water, polymer polyol, and isocyanate index through linear regression analysis of data generated using designed experiments which serve to separate interactions between direct variables. Density is modeled using its physical definition, density = mass/volume. Use of such a definition as a modeling base could allow more accurate extension to density ranges beyond the actual data range. Unfortunately, such a simple mathematical definition does not exist for IFD. However, accurate predictions of IFD are obtained using linear statistical modeling techniques. It must be remembered, however, that purely empirical models can only be confidently used over the specific data range from which the model was developed. Also, since catalyst and surfactant concentrations are not considered in the work, only quality “open” foams can reasonably be predicted. Foams “artificially” hard, due to low breathability, will not correlate with the models presented.

 

S93005 Emissions and Emission Control for Flexible Polyurethane Foam, Bert Veenendaal

This paper provides an assessment of the emissions generated during the manufacture of flexible polyurethane foam, the current status of control technologies, and recommendations for controlling these emissions.

S93002 Some Causes for Yellowing in Textile Materials, David M. Hall, Auburn University

The causes for yellowing in textile materials, specifically carpets and upholstery fabrics, has been under investigation for years. Several potential causes have been identified. The most common cause appears to be the inappropriate use of optical brighteners (ultraviolet absorbers) in the cleaning agent (shampoos etc.). Brighteners can give an optical illusion effect with some colors, specifically gray or charcoal shades. In any case, the color is often dulled by their use because they act to overdye the textile assembly a blue shade. Other causes for yellowing include the use of chlorine bleaching agents, the use of highly acidic or basic or anti microbial treatments, among others. One of the best analytical methods to determine the causes for discoloration in textiles is Energy Dispersive Analysis by X-Rays (EDAX). Other methods include spectroscopic analysis after reproducing the discoloration. Scanning Electron Microscopy (SEM) among others.

S93004 PURRC - A Flexible Polyurethane Foam Perspective, Andy Kirk, ICI Poylurethanes

Since the late 1980’s, there has been a growing concern about the environment in general, and about the efficient conservation of resources in specific. Members of the Steering Committee of the Polyurethane Division of the SPI became concerned about the industry’s customers’ perceptions that polyurethanes, as thermosets, were non-recyclable. Polyurethane foam customers compared polyurethanes to thermoplastics and perceived that they were not recyclable since they could not be melted and reprocessed once molded.

In 1990, the Steering Committee formed the PolyUrethanes Recycling and Recovery Council (PURRC). The goal set for the PURRC was to reduce significantly the amount of polyurethanes being disposed to landfills. Among PURRC’s objectives was 1) to establish parity when compared with alternative materials for which recycling was not perceived to be a problem; 2) recycle polyurethanes to remove the perceptions that they could not be recycled; and 3) create the environmental responsibility of polyurethanes as a positive design issue.

This paper discusses several processes for recycling, recovery and reuse of polyurethane foam. Among them are opportunities for removing and recovering and reusing flexible polyurethane foam from automobile seats and mattresses, adding reground flexible foam scrap to slab foam, chemical recycling and energy recovery.

Proceedings of the Polyurethane Foam Association Technical Program
October 1992

F92001 ABA Reduction Technology for the U.S. Flexible Slabstock Industry, Jackie Hicks, Dow Chemical Co.

Flexible Slabstock foam manufacturers are facing increasing pressure in many locations to reduce, restrict, or eliminate the types and quantities of ABA’s used in their facilities. Since the late 1980’s there has been a dramatic shift in the most commonly used ABA’s in slabstock production from chlorofluorocarbons (CFC’s) to methylene Chloride. CFC’s are no longer used in the U.S., to any significant degree, while some new ABA’s like methyl chloroform, acetone, hydrofluorocarbons (HCFC 141b) and pentane have entered to fill the gap left by the CFC’s.

This paper describes a new technology consisting of a novel polyol and additive which is available to assist foam manufacturers make the transition to reduced levels of ABA’s. Voranol A-T polyol has been developed which facilitates the manufacture of foams at reduced index, as well as at conventional indexes, while maintaining adequate physical properties. This polyol technology combined with a unique additive, which effectively alters the soft segment morphology of the resulting polymers, is a definite advancement in technology to manufacture ABA-Free slabstock foams.

 

F92003 Analysis for Free TDI in Flexible Polyurethane Foams, Dr. Rocco P. Triolo, Foamex

A study was undertaken to evaluate the procedure used in the 1990 SPI study on the analysis of free TDI in flexible polyurethane foams. Commercial foams were obtained and treated by auto-clave aging and solvent extraction. They were then analyzed along with unaged foams using the liquid chromatographic procedure used in the SPI study. The methodology of this test was to evaluate fresh foams, which might contain TDI, against foams that had been treated in order to ensure that no TDI was present. The results of the study demonstrated that the procedure is not sensitive enough to detect free TDI in the levels reported. It is most probable that the procedure resulted in extraction of materials which interfered with the analysis.

F92005 Meeting California Bulletin 133 Criteria: A Guide to Selecting Polyurethane Foam, Fabric, and Backcoating for Furniture Cushions, Richard S. Rose, Great Lakes Chemical Corporation

Interior furnishings have long been recognized as primary contributors to major fires. Despite need, obtaining a consensus on a full-scale test to regulate furniture flammability has been extremely difficult. Only in the last few years has California Bulletin 133 emerged as the standard for United States.

This paper summarized the California Bulletin 133 test results obtained using a mock-up consisting of two 18″ x 18″ x 3″ fabric covered polyurethane foam cushions. No barrier is used/. Instead, the normal backcoating, which is applied to the fabric to strengthen it, prevent wrinkles, and fraying, is flame retarded. The coating weight is increased to 60-80% of the fabric weight. Twenty six percent of a 2:1 blend of decabromophenyl oxide is added to the coating. The fabric drape and hand remain good at these coating levels.

The results of California Bulletin 133 testing, using typical contract furniture fabrics and available polyurethane foam and backcoating technology, provide a guide for passing the large-scale furniture standard. The effects of total fuel content and furniture design need to be taken into consideration as well.

F92007 E-Max, Environmental Friendly Foam Production, Johan Stoute, Unifoam AG

The E-Max process is based on total encapsulation of the foam block during the pouring of the block as well as during curing of the foam. This encapsulation prevents any uncontrolled escape of the process gases into the atmosphere. It also allows a reduction in ventilation capacity of some 97% during foaming compared to a standard Varimax production line.

This encapsulation is maintained during the curing phase which permits again a controlled capture of the emitted gases at the same low ventilation capacity.

The total control over gas emission during foaming and curing and the relatively small volume of highly concentrated gases makes it possible to capture auxiliary blowing agents efficiently for recycling. At the same time, other hazardous chemicals like TDI and amines other volatile components are scrubbed well.

An additional advantage of this encapsulation is the possibility to control the humidity of the ambient air during curing, which reduces the spread in hardness distribution.

Short blocks can now be produced to the exact width and grade specification economically. This is possible because width and formulation changes have been eliminated and start and stop scrap has been reduced to a minimum. The E-Max foaming process is based on the trough and fall plate technology of the Varimax, and permits the use of proven formulations and standard chemicals.

F92002 An Alternative to Methylene Chloride for Cleaning Polyurethane Foam Production Equipment, Tony Durante, International Specialty

The phase-out of ozone depleting compounds in no-essential use applications has prompted the search for alternative cleaning agents for polyurethane foam production equipment. The current usage of methylene chloride for all cleaning applications in the rigid and flexible foam markets has been estimated at about 13 million pounds. The paper covers a new program for replacing methylene chloride for cleaning polyurethane production equipment.

International Specialty Products (ISP) and several members of the urethane foam industry have worked to develop a new product called FoamFlush Urethane Remover. FoamFlush is a drop-in replacement for methylene chloride for cleaning polyurethane foam production equipment. It has been formulated to provide residue free cleaning and contains no water or other ingredients, which can interfere with foaming chemical reactions. It is more efficient than methylene chloride due to its low evaporation rate. It attacks both cured and uncured polymers as well as the coatings and adhesives commonly used in the foam cutting and fabricating areas. It cleans down to bare metal surfaces, and will not harm metals and composites used on foam production equipment. ISP has developed a new Responsible Care Program, called Respond, and they will arrange for testing, characterization and pick up of spent solvent, all at no charge to foam producers.

 

F92004 A New Reactive Blowing Agent for Flexible Polyurethane Foam, L. Bradford, R. Franklin and B. Williams, Akzo Chemicals Inc.

This paper introduces chemical blowing agents (CBA) which can, in some applications, replace physical blowing agents (PBA). The introduction of new reactions into a polymer process introduces a wide range of opportunities and challenges. This paper refers to the use of dialkyl dicarbonates and, specifically to an experimental product labeled E-90018T, which is essentially diisobutyl dicarbonate. The chemistry involved is discussed, as well as applications information relating to flexible urethane foams.

F92006 Crain Industries Enviro-Cure Technology Applied to the Vertifoam and Maxfoam Processes, Michael A. Ricciardi, Dzung (Jack) G. Dai, Crain Industries Inc.

Environmental pressure is increasing worldwide for foamers to reduce, or eliminate, chlorinated solvents used as auxiliary blowing agents from their production. Alternative blowing agents may only be available in limited quantities in the future. The impact on the flexible foam industry would be increased foam prices, and the elimination of certain soft grades of foam.

Alternative auxiliary blowing agents such as acetone or pentane introduce further problems, and are likely to be only short term solutions since emissions of any volatile organic materials will eventually tightly controlled.

This paper describes the Enviro-Cure process technology, which has proven capable of producing a full range of density and hardness (low to high) of flexible polyurethane foam without the use of auxiliary blowing agents. Water is used as a total blowing system.

The Enviro-Cure process technology is summarized for flexible polyurethane foam produced on Maxfoam and Vertifoam machines. All water blown foam formulations are provided for producing a full range of flexible polyurethane foam without any auxiliary blowing agents. The Enviro-Cure process technology also shows a significant economic advantage over other options available, and other intangible profits.

F92008 Low Density Foams Without Auxiliary Blowing Agents, Rapid Cooling Process for Use with Standard Foam Machines, H. Stone, E. Reinink, S. Lichvar, G. Rusenko, W. Carlson and C. Sikorski, General Foam Div. of PMC INC.

Historically, the reason for considering rapid cooling is the potential for reducing space requirements for cooling and storage of fresh foam. The need for eliminating undesirable emissions has become the major impetus for the current development. The potential for solving environmental problems both inside and outside the plant is a major incentive for considering rapid cooling.

All of the currently used or proposed auxiliary blowing agents, have some negative aspect, in terms of environmental issues. Therefore, this work is directed total elimination of auxiliary blowing agents. One major objective is to maintain the ability to produce low density and soft foams under these conditions without sacrificing quality.

The Rapid Cooling Process is located at the end of the pour conveyor section of the foam line. At this point the foam has solidified to the point of being capable of having the film removed. Once the film is removed, the foam is passed over a number of cooling stages, each one drawing air through the foam into collection chambers under the conveyor. At each stage the gases pass through an individual pump to an exhaust section. Several of these streams are combined and are passed jointly either through an emission control system or directly to the atmosphere.

The process currently consists of four phases. They are Preparation of Foam, First Stage Cooling, Second Stage Cooling, and Emission Control. A fifth stage consisting of heat recovery from the process will be added in the future. Each of the above phases is discussed in detail in the paper.

Proceedings of the Polyurethane Foam Association Technical Program
October 1991

F91001 Furniture and Flammability, The Effect of UK Legislation, David Hine, British Vita

This paper presents an overview of the effect that flammability legislation has had on the domestic UK foam and furniture industries over the last ten years. Relatively low cost furniture produced in the late 1960’s and early 1970’s sometimes included a combination of highly flammable fabrics and standard polyurethane foam. This combination resulted in some disastrous fire situations. Since it was impossible to develop a non-burning filling material, polyurethane or otherwise, to resist the very highly flammable fabrics that were being used at the time, it became necessary to involve the furniture manufacturers as well as the foam manufacturers.

As a result of the tremendous pressure being placed on both industries by the media and fire marshals, much work was done in improving these products. The development of melamine and combustion modified foam, saved the UK industry from a situation where polyurethane foam was almost going to be banned. This led to the disappearance of standard polyurethane foam, conventional high resilient foam, and the legislation of CMHR (Combustion Modified High Resilient) foam for domestic furniture applications.

This new fire legislation resulted in fewer foam manufacturers, tremendous resistance in the UK and Ireland to normalization of flammability legislation by the EEC, higher foam densities used for cushioning materials, replacement of PU foam by polyester fiber for back cushions and mattress topper pads, and fewer full foam mattresses.

It looks as if the British and Irish legislation will remain unaffected by any normalization, and there probably will not be any legislation at all in the rest of Europe on domestic furniture. The main emphasis now is on post consumer recycling. There is much work being done towards this end by BRMA and Europur.

 

F91003 Evaluation of Carpet Cushion in Simulated Installation Tests, O. M. Grace, D. C. Mente, R. F. Pask, BASF Wyandotte Corp.

Flexible polyurethanes are widely used in carpet cushion applications in the form of prime or rebond. In 1991 these two products represented 85% of the separate carpet cushion market. BASF conducted two types of in-use test programs on a series of carpet and underlay combinations to gain a better understanding of the performance of floor covering systems. The first test involved the use of contract walkers to obtain 100,000 traffic counts on the carpet / underlay combinations in a relatively short time, generally one or two months. This procedure was called the BASF Accelerated Corridor Test. The second type of in-use test involved installation of various types of underlay in a 75 foot long carpeted corridor at the BASF laboratory in Wyandotte, Michigan. This procedure was designated simply as the BASF Corridor Test. It involved an average traffic count of about 800 per month, and required about one year to obtain 100,000 traffic counts.

All of the underlay samples being tested in the two procedures ranged from 7/16 inch to ½ inch thickness, except for the 15.7 pcf prime underlay which was only ¼ inch thick. The IFD data shown in the report was obtained on the samples at the actual thickness using a 50 sq.in. pressure foot. The carpets were obtained and installed by a local retail supplier who services the BASF facility at Wyandotte. The carpet underlay rolls were also obtained from this supplier or directly from production of carpet underlay manufacturers. The only exceptions were the rolls of Duraplush™ underlay. The Duraplush™ underlay rolls were obtained from experimental runs on a production slabstock machine , and evaluated at 7/16 inch thickness.

The conclusions from these tests indicate that increasing density, within carpet cushion product groups, result in increased retention of cushion hardness (IFD). However, as expected, all products demonstrated some loss in hardness when subjected to fatigue testing.

All polyurethane cushion types, including Prime, Graft Prime, Rebond and Duraplush™ cushions, can provide excellent cushions if specified correctly. The 0.9 pcf prime foam had high fatigue loss properties and unacceptable height loss in all tests.

When produced at proper densities, durable, plush feeling carpet cushions are available from the Prime, Graft Prime, and Duraplush carpet cushion product.

The relationship between fatigue, hardness, and density is not straightforward. Density and hardness both affect the fatigue resistance of a carpet cushion.

Carpet performance was based upon delamination of the secondary carpet backing. Delamination did not occur with any of the cushions evaluated. The type of carpet selected, however, does have a profound effect on the performance of the cushion. These tests were conducted using a limited selection of carpets. More work needs to be done to develop this correlation.

F91005 Vertifoam and Enviro-Cure® Technology, M. A. Ricciardi, D. G. Dai, Crain Industries, Inc.

This paper introduces an environmental option for processing and manufacturing flexible polyurethane foam. The Enviro-Cure® Process is a continuation of the Vertifoam process. It is based on the rapid cooling of the porous foam material to prevent oxidation or autoignition. The process includes three cooling steps. In the first step cooled ambient air is drawn through the foam block, thereby cooling, dehumidifying, and removing fumes from said block, before being vented. The second step involves drawing cooled ambient air through the block to further cool it, and also condense and redeposit the sublimates in the block. In the third step ambient air is drawn through the foam to remove any remaining fumes, heat and moisture.

The present invention eliminates the need for auxiliary blowing agents in the formulation, since the water concentration of the formulation is increased sufficiently to accommodate for complete expansion of the foam. Enviro-Cure also allows the foam manufacturer to reduce TDI index.

The Enviro-Cure Process is currently in production in four Crain Vertifoam plant locations. Crain is currently in the process of adapting the process to Max Foam machines.

F91007 The Effect of Foam Density on Combustion Characteristics of Flexible Polyurethane Foam, Dr. H. Stone, M. Pcolinsky, Jr., General Foam, D. B. Parrish, G. E. Beal, Dow Chemical USA

Polyurethane foam has been reported to be more flammable and therefore more hazardous than other materials used for the same end uses. There is nothing obvious about their chemical structure to make such abnormal performance plausible. The generally low fuel contribution of a piece of foam, because of its low density, should be an advantage in most fire situations. The fact that such foams burn when exposed to an ignition source, and may burn quite rapidly, is most likely due to the combination of high surface area (due to its cellular structure), ready access to oxygen (due to the open cell structure) and low heat capacity or thermal inertia.

This study is directed to determining the effect of density, or readily available surface area, over a wide range on the combustion characteristics of flexible foams. It is generally accepted that one of the most meaningful methods to estimate hazard from a burning material is to measure the rate of heat released during combustion. This information can be used to extrapolate back to ease of ignition and forward to the probability of the fire spreading to other products.

Preparation of foams over a wide range of density, without materially changing chemical structure, is difficult. Density was varied for the main part of this work by thermally compressing the foam samples. The rate of heat release and associated parameters were then determined at various imposed thermal flux levels. Data were interpreted in terms of the physical and chemical structures of the foams.

In order to independently study the potential influence of the thin skins formed by the thermal compression, a second part of this study used samples of one foam of varying density produced by synthesis. In order to minimize changes in chemical structure, the density of these samples was varied by changing the amount of auxiliary blowing agent. Study of these at one level of radiant flux demonstrated no effect due to skinning.

It was found that compression or density changes significantly influence the ease of ignition and burn rate of samples burned on the OSU calorimeter. The effects are more readily apparent when data are normalized for density by dividing rates by density.

There are major differences in burn behavior due to type of foam. The effects are most pronounced with the products least resistant to ignition.

There are significant differences in behavior between char forming and melting systems of combustion modifiers for flexible polyurethane foam.

Total heat release is a function both of type of foam involved (available fuel) and the imposed radiant flux.

The study of maximum rate of heat release (MRHR) divided by density gives the best insight in changes in behavior with changes in density and imposed heat flux. The observed behavior follows three general patterns.

F91002 Textiles, Foam and Safety, Diane Poole, Raytex Fabrics, Inc.

This paper discusses flammability in relationship to furniture, textiles, clothing and other related products. The presentation is divided into four sections: 

1) Clarification of current NFPA 101 and Related Safety Codes

2) Flame Retardant Textile Fabric Terminology

3) Examples of Inherent and Intrinsic Fabrics

4) Establishing and Adopting A Safety Code

The author concludes that “textiles, foam and safety codes are closely related and we must all work together to help the people who are our customers to understand the technical aspects of flame retardant products. We can only do that by better educating ourselves.”

 

F91004 CFC Free Soft Foam Using a New Functional Additive, T. H. Austin, J. E. Knight, Arco Chemical Co.

Worldwide concern about the environmental impact of chlorofluorocarbons (CFC’S) in the atmosphere has prompted considerable research effort to eliminate CFC’s from flexible polyurethane slab foam production. This work, presented in this paper, has been directed toward the creation of slab foam technology that does not incorporate any auxiliary blowing agents in the foam production.

Soft flexible slab foams have been produced, by reducing the isocyanate index of the formulation. This approach, however, is accompanied by loss of foam physical properties and processing latitude. The incorporation of polyols designed specifically for lower isocyanate index formulations will alleviate the expected loss in foam physical properties and foam processing problems. The work, reported in this paper, is an extension of this low index technology.

A new proprietary functional additive, Arcol DP-1022, is introduced which allows further reduction of the isocyanate index. Foams have been prepared in the range of 75 to 95 index. Foam Machine processing is good and tin catalyst latitude has been maintained. Data is presented which demonstrates that physical properties are adequate at reduced isocyanate index. This approach broadens the range of soft grades available to the industry without the use of auxiliary blowing agents such as CFC’s.

F91006 Evaluation of Flexible Polyurethane Foam for Use in Upholstered Furniture and Mattresses, T. L. Moore, C. Sepulveda, Dow Chemical Corp.

The Flexible Foam Technical Committee of the SPI Polyurethane Division and the Technical Committee of the Polyurethane Foam Association (PFA) began working on the problem of measuring fatigue of flexible slabstock foams in 1979. In 1982, a progress, and status report was presented by Dr. Herman Stone. In 1986, a study of the correlation of laboratory dynamic fatigue to in-use fatigue testing of chair cushions was presented by Jim Knight. In 1988, a study of the correlation of laboratory dynamic fatigue to in-use fatigue testing of full foam mattresses as presented by Terry Moore and Garry Statton.

The reasons for the studies reported here were :

1) to develop additional technical data on the in-use fatigue of chair cushions

2) to correlate Rollator fatigue testing between two labs of variou grades of full foam mattresses

3) to develop pressure point reduction data on several commercially available full foam mattresses

 

F91008 Fatigue Testing of High Performance Flexible Polyurethane Foam, S. L. Hager, T. A. Craig, Arco Chemical

Fatigue testing is used to predict how the initial cushioning characteristics of foam will deteriorate over time of use. Both static compression and dynamic flexing fatigue tests are commonly used in the industry to evaluate and sometimes select foam cushioning. Over the years, a number of fatigue studies have been performed on flexible polyurethane foams: sometimes in conjunction with end-use field evaluations. The accelerated lab tests have generally followed the static force loss and dynamic fatigue tests described in ASTM method D 3574-86 or modified versions of these. Questions have raised regarding the validity of the static force method for predicting long term durability.

In this paper, the impact that certain variations in test procedure, sample preparation and foam load compression profile have on test results are investigated. Conventional and high performance HR foams of the same density and 25% IFD, but having significantly different cushioning profiles are compared. The relationship between end use performance and accelerated testing procedures are discussed.

It was found that accelerated durability testing of flexible polyurethane foam by standard static and dynamic fatigue tests can be significantly influenced by variations in the test procedure, foam type and in the specimen preparation. Strict adherence to the specified procedures may give an incomplete and sometimes inaccurate assessment of relative foam performance.

A summary of the conclusions, regarding the specific fatigue tests, are provided in the paper. Foam comparison conclusions are largely based on the 1.8 PCF/27 IFD conventional and high performance HR foam grades.