abstract |
PROCESS FOR IMPROVING THE PROPERTIES OF WATER VAPOR PERMEABLE MICROPOROUS SHEET OF NON-FIBROUS THERMOPLASTIC ELASTOMERIC POLYURETHANE OF THICKNESS SUITABLE FOR USE AS A SUBSTITUTE FOR SHOE UPPER LEATHER. THE SHEET IS HEAT TREATED AT A TEMPERATURE BELOW ITS COLLAPSE TEMPERATURE SO THAT IT SHRINKS AT LEAST 5% IN AREA. D R A W I N G |