Patent ID: 7972981
Filing Date: 2011-07-05
Classification: B29C,B32B,D01D,D01F,D04H,D06C,Y10T

Abstract:
1. A moisture vapor permeable, water impermeable composite sheet material having strength and barrier properties making it suitable for use as a housewrap, comprising a nonwoven substrate comprising polymeric filaments randomly disposed and area bonded to one another to form a spunbond nonwoven web in which the filaments are bonded to one another throughout the fabric at locations where the randomly disposed filaments overlie or cross one another, the web having a grab tensile strength of at least 178 Newtons in at least one of the machine direction (MD) or the cross-machine direction (CD), one surface of the nonwoven substrate defining one outer surface of the composite sheet material, and a polyolefin film extrusion coating layer extending uninterruptedly and continuously over the opposite surface of said substrate and intimately bonded thereto, said extrusion coating layer defining the opposite outer surface of the composite sheet material, said composite sheet material having been incrementally stretched in at least one of the MD or CD to form incrementally stretched zones separated by zones of substantially unstretched or less stretched material, and said film layer having micropores formed therein by the incremental stretching to impart to the composite sheet material a hydrostatic head of at least 100 cm and an air leakage rate of less than 0.02 L/(s·m