Rigid Polyurethanes Systems for Metal-Faced Sandwich Panels

Abstract

Metal-faced sandwich panels with polyurethane foam-filled cores have become increasingly successful in satisfying the needs of the construction industry, especially with the growing emphasis on system building and energy conservation. Global awareness of the need to protect the environment is also growing, and foam-cored panels have an important role to play in this respect; energy savings are provided through building insulation and contribute significantly to the preservation of food supplies.

In order to maintain their contribution to the global environment, however, traditional CFC blowing agents must be replaced with more environmentally acceptable altematives. Although it has not been possible to identify a single universal replacement for CFC 11, a variety of polyurethane foam systems has been developed for use with the altematives in order to comply with, and possibly anticipate, the phase-out programmes.

The industry already has the means to overcome most of the immediate problems posed by the need to eliminate CFCs. CFC 11 can, for instance, be replaced in the next few years by HCFCs, without losing any of the properties required by sandwich panel manufacturers. This paper reviews ongoing development for the longer term, looking at systems which will enable sandwich panels to continue to develop and for their energy saving characteristics to be fully utilised.