Appliance Foams with Reduced Levels of HFC-245fa

The HCFC-141b blowing agent used in most appliance foams in the United States is scheduled for phase-out on January 1, 2003. The most promising replacement is HFC-245fa. It has met many of the requirements for a blowing agent such as zero ozone depletion potential (ODP), low toxicity, good miscibility with polyols, low vapor phase thermal conductivity, and a reasonable boiling point of 59.5°F (15.3°C). Also, because it is non-flammable, HFC-245fa will save manufacturers of household refrigerated appliances the costs associated with retrofitting their factories to safely handle flammable blowing agents. However, refrigerator manufacturers have concerns about higher product manufacturing costs. Foam insulation costs may rise. New processing equipment and procedures may need to be installed in factories for new blowing agents. Refrigerator producers want to know if their foam operation productivity and product quality will be affected. They are also concerned about staying compliant with the 2001 Energy Consumption Standards. This paper will report on work done at Bayer Corporation to address these concerns. We will show the effect of lowering the level of HFC-245fa on foam thermal conductivity, physical properties and demold characteristics. Thermal stability and pressure generation studies on HFC-245fa containing masterbatches are presented which provide insight into handling the new generation formulations. The information presented will assist household refrigerator producers in selecting the most cost-effective solution to their manufacturing concerns when replacing HCFC-141b with HFC-245fa.