Corona discharge treatment of foam fibrillated webs

Claim 1

A process of producing a foam fibrillated fibrous web comprising extruding a resinous composition at least 70 weight percent of which is a poly α-olefin, and a gaseous material mixed with said polyolefin from a die into a zone of reduced pressure to produce an extrudate, withdrawing said extrudate from said die by a first take-up means at a linear rate from 2 to 25 times the linear rate at which said polyolefin reaches the die lips to form a foam fibrillated web, stretching said foam fibrillated web from 2 to 10 times in the machine direction, and surface treating the stretched foam fibrillated web with a corona discharge at an intensity of from 1 to 75 watt-minutes per square foot at about 20 to about 150°C whereby the fibrous web has improved adhesion ability with itself.