Literature

Proceedings of the Polyurethane Foam Association Technical Program October, 1992

ABA Reduction Technology for the U.S. Flexible Slabstock Industry, Jackie Hicks, Dow Chemical Co., Proceedings of the Polyurethane Foam Association, October 26, 1992.

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.

An Alternative to Methylene Chloride for Cleaning Polyurethane Foam Production Equipment, Tony Durante, International Specialty Products Proceedings of the Polyurethane Foam Association, October 26, 1992.

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.

Analysis for Free TDI in Flexible Polyurethane Foams, Dr. Rocco P. Triolo, Foamex, Proceedings of the Polyurethane Foam Association, October 26, 1992.

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.

A New Reactive Blowing Agent for Flexible Polyurethane Foam, L. Bradford, R. Franklin and B. Williams, Akzo Chemicals Inc., Proceedings of the Polyurethane Foam Association, October 26, 1992.

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.

Meeting California Bulletin 133 Criteria: A Guide to Selecting Polyurethane Foam, Fabric, and Backcoating for Furniture Cushions, Richard S. Rose, Great Lakes Chemical Corporation, Proceedings of the Polyurethane Foam Association, October 26, 1992.

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.

Crain Industries Enviro-Cure Technology Applied to the Vertifoam and Maxfoam Processes, Michael A. Ricciardi, Dzung (Jack) G. Dai, Crain Industries Inc., Proceedings of the Polyurethane Foam Association, October 26, 1992.

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.

E-Max, Environmental Friendly Foam Production, Johan Stoute, Unifoam AG, Proceedings of the Polyurethane Foam Association, October 26, 1992.

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.

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., Proceedings of the Polyurethane Foam Association, October 26, 1992.

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.