Proceedings of the Polyurethane Foam Association Technical Program May and October, 1995
Catalyzing Products Stewardship in Polyurethane’s, Charles M. Bartish, Air Products and Chemicals, Inc., Proceedings of the Polyurethane Foam Association, May 18, 1995.
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.
Overview on the Concerns Facing Foam Fabricators from an Adhesive Supplier Standpoint, William Hazelgrove, Imperial Adhesives, Proceedings of the Polyurethane Foam Association, May 18, 1995.
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.
Control and Monitoring of VOC Emissions in Urethane Foaming Operations, Charles Quinlan, KSE, Inc., Proceedings of the Polyurethane Foam Association, May 18, 1995.
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.
Phase 1, UFAC Open Flame Tests, Hugh Talley, The Hugh Talley Company, Proceedings of the Polyurethane Foam Association, May 18, 1995.
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.
Electronic Communication for the PFA, Tea Canna and Bob Luedeka, OSI Specialties/J. P. Hogan, Proceedings of the Polyurethane Foam Association, May 18, 1995.
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.
The Recyclability of Polyester Fiber and Flexible Polyurethane, David Gibala, ARCO Chemical Co, Proceedings of the Polyurethane Foam Association, May 18, 1995.
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
Durability Testing of Flexible PUF and Polyester Fiber for Furniture Applications, Roy Pask, BASF, Michael McGovern, ARCO Chemical, Proceedings of the Technical Program of the Polyurethane Foam Association Meeting, Arlington, VA, May 18, 1993
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.
Enhanced Wear and Appearance Retention of Carpet When Cushion is Used, William Wald, Technical Director, Carpet Cushion Council, Proceedings of the Polyurethane Foam Association, May 18, 1995.
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.
Developing Federal Hazardous Air Pollutant Standards for the Flexible Polyurethane Foam Industry, Phil Norwood, EC/R Incorporated, Proceedings of the Polyurethane Foam Association, May 18, 1995.
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.
Evaluation of Antioxidants with Low Volatility for Scorch Protection of Polyurethane Foams, Robert E. Lee, Great Lakes Chemical Corp., Proceedings of the Polyurethane Foam Association, October 12 & 13 1995.
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.
New Generation Flame Retardant Polyol, J. J. Lear, O. D. Sloan, P. Motte, Arco Chemical Company, Proceedings of the Polyurethane Foam Association, October 12 & 13, 1995.
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.
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), Proceedings of the Polyurethane Foam Association, October 12 & 13 1995.
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.
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, Proceedings of the Polyurethane Foam Association, October 12 & 13, 1995.
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.
A New Public Relations Program for Flexible Polyurethane Foam, Helen Sullivan, Arnold Public Relations, Proceedings of the Polyurethane Foam Association, October 12 & 13, 1995.
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.
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, Proceedings of the Polyurethane Foam Association, October 12 & 13, 1995.
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.
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, Proceedings of the Polyurethane Foam Association, October 12 & 13, 1995.
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.
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, Proceedings of the Polyurethane Foam Association, October 12 & 13, 1995.
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.
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, Proceedings of the Polyurethane Foam Association, October 12 & 13 1995.
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.
All MDI Prime Carpet Cushion, Robert J. Lockwood, ICI Polyurethanes, Proceedings of the Polyurethane Foam Association, October 12 & 13, 1995.
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.
New CarDio Installations, Jerry Pool, The Research Pool, Proceedings of the Polyurethane Foam Association, October 12 & 13, 1995.
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.
Copyright © 2013 POLYURETHANE FOAM ASSOCIATION. All rights reserved.