Published: December 2002
Polyurethanes are among the most widely used and versatile of all polymer forms, ranging from soft elastomers and foams to hard plastics. Since the global phase-out of CFC's required by the Montreal Protocol to reduce ozone depleting chemical emissions, a number of various alternative expansion agents are now being used by the polyurethane manufacturing industry to produce both cushion and insulation foam products. In addition, the U.S. EPA is attempting to regulate U.S. manufacturers by the amount of blowing agent used per foam grade.
The development and the diversification of many foam product foams and grades has been evolving since the 1950's by pioneering researchers to learn how to physically control the blowing chemistry to produce new products with different machine techniques. Over many years, this art has been advanced by many other scientists and engineers in multiple companies around the world. Since 1991 many new innovative formulation chemistries and manufacturing processes have been developed for polyurethane foam product manufacturing that either reduce or eliminate the use of ozone depleting blowing agents in the manufacture of flexible and rigid foams. This report reviews new technologies developed since our last report, with a focus on variable pressure polyurethane foam manufacturing processing to produce flexible foam products without the direct use of blowing agents. In addition, this report also reviews the use of alternative physical blowing agents for the manufacture of rigid laminated boardstock to be used as building construction insulation material. Two preliminary process economic evaluations are presented for flexible and rigid foam product production based on designs original to this report.
In addition this report presents a description of the fundamentals of foam formation, provides guidelines and technical options for selecting non-ozone depletion technologies, and reviews the current status and forecasts for production of polyurethane foams by major world region.