Patent ID: 7118639
Filing Date: 2006-10-10
Classification: A61F,B32B,Y10T

Abstract:
1. A method for producing a structured composite material having a plurality of apertures for accommodation passage of fluids through the structured composite material, the method comprising the steps of: forming a first layer having a first shrinkage extent, said first layer comprising a fibrous thermoplastic nonwoven web; extruding a heat shrinkable second layer onto the first layer, the second layer comprising a thermoplastic film and having a second shrinkage extent different from the first shrinkage extent; forming the plurality of apertures only through the second layer after extrusion; and differentially heat shrinking the second layer relative to the first layer to increase a bulk of the composite material and produce the structured composite material; whereby the apertures are effective in transferring particles into the structured composite material and the first layer is effective in retaining them.