Shoe stiffener and method of making same

Claim 1

IN A METHOD OF MAKING A SHOE STIFFENER MATERIAL THE STEPS COMPRISING: (A) IMPREGNATING A FIBROUS BASE OF NAPPED FABRIC WITH AN AQUEOUS MIXTURE OF A REACTIVE WATER-SOLUBLE UREA-FORMALDEHYDE RESIN STABILIZED IN PARTICALLY CONDENSED CONDITION, SUFFICIENT INERT THIXOTROPIC THICKENING GEL, BETWEEN ABOUT 1% AND 5% BASED ON THE DRY WEIGHT OF THE RESIN, TO CAUSE SAID RESIN TO DRY IN DISCONTINUOUS POROUS FILMS, AND 80% TO 120% OF FINELY DIVIDED ACID-RESISTANT FILLER BASED ON THE DRY WEIGHT OF THE RESIN, SAID MIXTURE CONTAINING BETWEEN 55% AND 65% OF SOLIDS; (B) SUBJECTING SAID IMPREGNATED FABRIC TO A NAPPING OPERATION TO DISTEND THE FIBERS OF THE FABRIC AND TO METER THE QUANTITY OF IMPREGNANT IN AND ON THE FABRIC TO PROVIDE A MATRIX CONTAINING WHEN DRY BETWEEN 200% AND 300% OF THE WEIGHT OF THE FABRIC; (C) HEATING SAID MIXTURE ON AND WITHIN SAID FABRIC, WHILE SAID FIBERS ARE MAINTAINED IN DISTENDED CONDITION BY THE THIXOTROPIC ACTION OF SAID GEL, UNTIL AT LEAST ABOUT 95% OF THE MOISTURE IS REMOVED FROM SAID AQUEOUS MIXTURE AND A DRIED, POROUS MATRIX IS FORMED ON SAID DISTENDED FIBERS AND WITHIN THE BODY OF THE FABRIC; AND (D) PRESSING SAID FABRIC IN SUCH DRIED CONDITION AND WHILE IT CONTAINS NOT MORE THAN 5% OF WATER TO FRACTURE SAID POROUS MATRIX ON SAID DISTENDED FIBERS AND WITHIN THE BODY OF THE FABRIC AT A MULTIPLICITY OF POINTS THROUGHOUT ITS EXTENT TO FORM A STIFFENER MATERIAL WHICH MAY BE RENDERED SOFT AND FLACCID SUBSTANTIALLY INSTANTANEOUSLY UPON IMMERSION IN WATER.