Patent ID: 7713894
Filing Date: 2010-05-11
Classification: D04H,D06C,Y10T

Abstract:
1. An elastic thermally bonded nonwoven web consisting essentially of polypropylene fibers, which has an elasticity in the cross direction of at least 70% recovery from a 100% elongation, and at least 60% recovery from a 150% elongation, and which has a ratio of elongation at break in the cross direction to the elongation at break in the machine direction of at least 8, wherein the elasticity of the nonwoven web is imparted by a process comprising the following steps: (a) providing a thermally bonded nonwoven precursor web consisting essentially of polypropylene fibers; and (b) subjecting the precursor web of step (a) to a drawing treatment in a machine direction at a drawing rate of from 45 to 70%, and a strain rate within a range of from 1000 to 2400%/min at a temperature between the softening point and the melting point of the fibers for preparing the elastic thermally bonded nonwoven web, wherein the polypropylene fibers consist essentially of polypropylene that is homogeneous in the cross-section in the solid state.