Method of bonding fibrous structures made from fibers or filaments of polyolefine polymers

Claim 1

IN A METHOD OF JOINING TOGETHER A PAIR OF FABRICS EACH MADE OF FILAMENTOUS STRANDS OF A POLY-ALPHA-OLEFINE POLYMER, WHEREIN THE STRANDS OF ONE FABRIC ACROSS THE STRANDS OF THE OTHER FABRIC AT A PLURALITY OF CROSSING POINTS, AND WHEREIN THE STRANDS OF SAID FABRICS ARE BONDED AT SAID CROSSING POINTS, THE IMPROVEMENT COMPRISING SO APPLYING TO A SURFACE OF EACH FABRIC AN AQUEOUS DISPERSION OF A BONDING AGENT CONSISTING ESSENTIALLY OF A POLY-ALPHA-OLEFINE POLYMER HAVING ITS CHAINS DIFFERENT IN MOLECULAR STRUCTURE FROM THESE OF THE STRAND POLYMER AND HAVING A PERMANENT MELTING POINT AT LEAST 25* C. BELOW THAT OF THE POLYMER OF SAID FABRICS, SAID BONDING AGENT POLYMER BEING ENTIRELY CHEMICALLY COMPATIBLE WITH THE POLYMER OF SAID FABRICS, AS TO CAUSE A MAJOR PORTION OF SAID DISPERSION TO COLLECT AT SAID CROSSING POINTS, THEN IMPOSING ONE FABRIC OVER THE OTHER TO OVERLAP THEM AND SO AS TO BRING SAID AGENT-TREATED SURFACES INTO CONTACT WITH EACH OTHER, SUBJECTING THE OVERLAPPING FABRICS TO HEAT TREATMENT AT A TEMPERATURE INTERMEDIATE THAT OF THE MELTING POINTS OF THE POLYMERS OF SAID FABRICS AND OFSAID AGENT WHILE PRESSING THE FABRICS TOGETHER TO MAINTAIN CONTACT, SAID TEMPERATURE BEING SUFFICIENTLY HIGH AND MAINTAINED FOR A SUFFICIENT LENGTH OF TIME TO FUSE SUBSTANTIALLY ALL OF THE POLYMER OF SAID AGENT AND TO SOFTEN OR FUSE ONLY THE SURFACE OF SAID STRANDS, WHEREBY SAID FUSED AGENT BECOMES SUFFICIENTLY FLUID TO ENABLE SAID MAJOR PORTION THEREOF TO COALESCE WITH SAID STRAND SURFACES AT SAID INTERCROSSINGS, AND COOLING THE FABRICS TO HARDEN SAID FUSED AND SOFTENED PORTIONS TO FORM BONDS BETWEEN SAID STRANDS AT SAID CROSSING POINTS.