Unified paper sheet, process of making, and pressure-sensitive adhesive tape made therefrom

Claim 1

A PRESSURE-SENSITIVE ADHESIVE MASKING TAPE COMPRISING A UNIFIED PAPER BACKING COATED ON ONE SURFACE THEREOF WITH A PRESSURE-SENSITIVE ADHESIVE, SAID TAPE BEING WOUND IN SUCCESSIVE CONVOLUTIONS UPON ITSELF TO FORM A ROLL FROM WHICH IT IS RAPIDLY UNWINDABLE WITHOUT DELAMINATION OF SAID PAPER BACKING, AND WHEN SO UNWOUND, IS EXTENSIBLE TO THE EXTENT OF AT LEAST ABOUT 5% IN LENGTH WHEN STRETCHED LENGHTWISE; SAID UNIFIED PAPER BACKING BEING COMPOSED OF DISTORTED, LONGITUDINALLY CROWDED CELLULOSE FIBERS, BONDED TOGETHER BY ABOUT 10-30% BY WEIGHT OF THE DRY FIBERS OF A HIGH MODULUS EXTENSIBLE POLYMERIC UNIFYING MATERIAL DISTRIBUTED WITHIN THE BODY OF THE BACKING TO INCREASE THE FIRMNESS AND DELAMINATION RESISTANCE OF THE BACKING, SAID UNIFYING MATERIAL BEING IN THE TRANSITION RANGE OF VISCOELASTIC BEHAVIOR; THE FIBERS OF SAID BACKING BEING DISTORTED AND LONGITUDINALLY CROWDED BY SUBJECTING A STARTING WEB HAVING AN ELONGATED WEB BODY COMPOSED OF CELLULOSE FIBERS AND HAVING TWO OPPOSED WEB FACES, WHILE HEATED TO A TEMPERATURE SUFFICIENT TO GENEATE MOISTURE VAPOR, SIMULTANEOUSLY TO (A) SUFFICIENT CONFINING PRESSURE, ACTING PERPENDICULARLY WITH RESPECT TO SAID WEB FACES TO PREVENT SUBSTANTIAL CRINKLING OF THE WEB BODY, AND (B) SUFFICIENT COMPACTING FORCE, ACTING LONGITUDINALLY WITH RESPECT TO THE LENGTH OF SAID WEB (I) TO CAUSE THE WEB FIBERS TO BE LONGITUDINALLY DISTORTED AND FORCED CLOSER TOGETHER IN CHANGED ORIENTATION LENGHTWISE WITHIN THE WEB BODY AND (II) TO CAUSE THE WEB BODY THEREBY TO CONTRACT IN LENGTH BY AT LEAST ABOUT 5%; WHEREBY AN INEXPENSIVE TAPE IS PROVIDED CHARACTERIZED BY (A) HIGH RESISTANCE TO DELAMINATION, (B) HIGH COMFORMABILITY, AND (C) GOOD FIRMNESS.