HFC-356,a Zero ODP Blowing Agent Candidate for North American Appliance Foam Formulations

Abstract

The household refrigeration industry in the U.S. is being challenged on two issues. These issues are depletion of the ozone layer by CFCs and federally mandated energy consumption standards for the products sold in the U.S. The global issue of ozone depletion affects all domestic appliance producers in North America. The energy consumption issue, however, only affects those producers who desire to sell their products in the U.S.

In addressing the ozone depletion issue, the North American manufacturers of household refrigerators and freezers have accepted HCFCs as the most promising available blowing agent substitutes for CFCs in their polyurethane foam insulations. Over the past few years a great deal of effort has gone into the development of polyurethane foam insulations blown with HCFCs which have the properties required by the North American household refrigeration industry. Between now and 1995 we expect a conversion of the industry from CFC to HCFC blown polyurethane foam insulations.

HCFCs, however, are only transition materials. Since their ozone depletion potentials are not zero, they too are scheduled for production caps and phaseout under the provisions of the amendments to the Montreal Protocol. Thus, it is necessary to begin the development now on the next generation of North American appliance foam formulations which do not use ozone depleting substances as blowing agents.

Our previous work has shown the ability to develop appliance foams blown with HFC-356 which satisfactorily meet the technical requirements of the European appliance industry in many important areas. The design and construction differences between European and North American refrigerated appliances, however, does not allow direct translation of appliance foam technology. The foam flowability, k-factor, density and demold requirements are not the same. Consequently, our development effort has now expanded to address the needs of the North American domestic appliance producer. Results of work done with HFC-356-based foam systems engineered for the North American appliance insulation market are presented with comparisons to known CFC and HCFC blown appliance foams.