Patent ID: 7470389

Claim:
A method for preparing a nonwoven fibrous web comprising a) extruding a stream of filaments from a die having a known width and thickness; b) directing the stream of extruded filaments through a processing chamber that provides attenuation of the extruded filaments, the processing chamber being defined by two narrowly separated walls that are parallel to one another, parallel to said width of the die, and parallel to the longitudinal axis of the stream of extruded filaments; one or both of the walls being movable toward and away from the other wall to establish a desired spacing between the walls; c) intercepting the stream of filaments passed through the processing chamber on a collector where the filaments are collected as a nonwoven fibrous web; and d) selecting a spacing between the walls of the processing chamber that causes the stream of extruded filaments to spread and be collected as a functional web at least 50% greater in width than said width of the die; the processing chamber having a configuration that allows the stated spreading of the web.