Canadian Plastics

Bayer testing compounds in search for new PU foam blowing agent

Canadian Plastics   

Appliance manufacturers are in the home stretch of a race to find new blowing agents for polyurethane foamed insulation used in refrigerator cabinets. Although the current HCFC-141b agent is less ozon...

Appliance manufacturers are in the home stretch of a race to find new blowing agents for polyurethane foamed insulation used in refrigerator cabinets. Although the current HCFC-141b agent is less ozone depleting than previous CFCs, the US EPA has mandated a phase-out by the end of 2002, forcing the appliance industry to look at several options.

One non-fluorinated hydrocarbon agent, cyclopentane, appears to be out of the running, at least in Canada and the U.S., says Joe Sutej, Bayer’s director of appliance business unit: “The up-front capital investment required to handle cyclopentane safely and the cost of lost production while converting factory equipment to a cyclopentane system appears to be higher than U.S. and Canadian based manufacturers are willing to accept.”

Alternatives have boiled down to either HFC-245fa or HFC-134a, neither of which appears to have a definitive advantage for appliance manufacturers. HFC-245fa features an insulation value which is close to the current HCFC-141b, but at a cost premium, while the cheaper HFC-134a agent lags the current product’s insulation value by approximately 10 percent. Bayer reports that capital costs of conversion are minimal for either alternative. The final round may go to HFC-245fa, however, if energy efficiency requirements force major appliance product redesign (i.e. more foam) to accommodate the lower insulating value of HFC-134a. Current Bayer research is looking for ways to optimize the quantity of the more expensive HFC-245fa agent to meet cost and performance targets. “We are trying to determine if there are optimal parameters manufacturers can use that will produce the best compromise between performance and cost,” says Sutej.

New blowing agents add another refrigerator cost/performance consideration: the inner liner. Solvent attack of blowing agents on the ABS-based liner materials is a problem which Bayer (among others) is actively researching at the firm’s pilot appliance plant in Pittsburgh, Pennsylvania, and at Bayer’s Styrenics Application Development Center in Springfield, Massachusetts. New thermoplastics designed for compatibility with both new blowing agents are currently under development using technology based on Bayer’s current Lustran Guardian ABS products.



A few suggestions from Civiera & Silver International Inc. (Holden, MA) to get the best price possible for your plastic scrap and to avoid claims from your scrap buyer. Civiera & Silver buys, sells and recycles engineering resins.

1. Avoid cross contamination of resins at the press by adopting procedures to always keep different resins, types and grades separate.

2. Avoid cross contamination during grinding by using dedicated grinders or implementing procedures to dismantle and clean grinders during material changeovers.

3. Avoid mixing filled and unfilled versions of the same generic resin type, and grind colors separately, or at least keep natural and blacks separate from other colors. Unfilled versions are usually more valuable, and natural is always worth more than colors. Try not to mix whites and light colors with blacks.

4. Always use good, serviceable packing to avoid claims for losses, repacking and freight.

5. Label all packages clearly to avoid any confusion as to their contents. Black M90 Acetal Regrind is better than Black Acetal.

6. When you list your material for sale, be as specific as possible. Describe quantities, colors, resin and grade types.

7. When you ship your plastic scrap, number all packages and generate a detailed packing list and invoice giving individual package weights (gross, net and tare). This is your proof of what you have shipped.


An on-line Recycled Plastics Market Database that contains more than 1650 names of companies in the North American recycling industry (post-industrial and post-consumer) is now on the Environment and Plastics Industry Council (EPIC, Mississauga, Ont.) web site (

The new database is a result of a partnership between EPIC and the American Plastics Council (Arlington, VA). It provides a list of buyers and sellers of recycled plastics located in Canada and the United States. Users may search by region, plastic type and source. Sources include post-consumer residential plastics; post-consumer industrial, commercial and institutional plastics; and industrial scrap plastics/pre-consumer plastics.


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