Patent ID: 8328968
Filing Date: 2012-12-11
Classification: B29C,B32B,D01D,D01F,D04H,D06C,Y10T

Abstract:
1. A method of preparing a composite sheet material having strength and barrier properties suitable for use as a housewrap, the method comprising: extrusion coating a polyolefin film layer onto a surface of an area-bonded, spunbond nonwoven substrate to form a composite sheet material, the composite sheet material 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), and incrementally stretching the composite sheet material, wherein the stretching step comprises incrementally stretching the composite sheet material in at least one of the CD or the MD to form incrementally stretched zones separated by zones of substantially unstretched or less stretched material to impart to the composite sheet material a hydrostatic head of at least 100 cm, and a moisture vapor transmission rate (MVTR) of at least 35 g/m2/24 hr. at 50% relative humidity and 23° C.