Vinyl sponge laminate

Claim 1

THE PROCESS OF MAKING A VINYL SPONGE LAMINATE COMPRISING THE STEPS OF: CONFINING A VINYL PLY CONTAINING A BLOWING AGENT BETWEEN A FACE AND BACK VINYL PLY OF SIMILAR COMPOSITION AND THICKNESS; CONFINING THE PLIES SO DISPOSED BETWEEN FIRST AND SECOND COOPERATING PRESSURE BANDS OF DIMENSIONALLY STABLE MATERIAL, THE FIRST BAND ADAPTED TO EXERT A CONTINUOUS RELATIVELY HIGH PRESSURE OF FROM 5 TO 70 LBS. PER SQUARE INCH AGAINST THE PLIES TO EFFECT THE LAMINATION OF SAID PLIES AND THE FIRST PRESSURE BAND CHARACTERIZED BY A SMOOTH SURFACE IN CONTACT WITH THE SURFACE OF THE FACE PLY WHILE THE SECOND PRESSURE BAND IS CHARACTERIZED BY A ROUGHENED SURFACE IN CONTACT WITH THE SURFACE OF THE BACK PLY; ADVANCING SAID BANDS OF INTERPOSED PLIES THROUGH A FIRST HEATING ZONE OF RELATIVELY LOW TEMPERATURE SUFFICIENT TO EFFECT A SOFTENING AND A LAMINATION OF SAID PLIES AT SAID HIGH PRESSURE, BUT AT A TEMPERATURE INSUFFICIENT TO ACTIVATE THE BLOWING AGENT, THEREBY FORMING A GAS RETENTIVE LAMINATE; ADVANCING THE LAMINATED PLIES THROUGH A SECOND HEATING LONE OF RELATIVELY HIGH TEMPERATURE SUFFICIENT TO ACTIVATE THE BLOWING AGENT AND TO CONVERT THE PLY CARRYING THE BLOWING AGENT TO A SPONGE CONSISTENCY WHILE THE LAMINATED PLIES ARE COMBINED BETWEEN SAID PRESSURE BANDS AT A RELATIVELY LOW PRESSURE, WITH THE SECOND PRESSURE BAND EXERTING A RELATIVELY LOW PRESSURE AGAINST THE PLIES, THE LOW PRESSURE BEING SUFFICIENT TO SUPPORT AND CONFINE THE HEAT SOFTENED PLIES BUT INSUFFICIENT TO PREVENT THE FORMATION OF THE SPONGE PLY.