Patent ID: 6709718
Filing Date: 2004-03-23
Classification: B29C,B29K,C08J,D06M,H01J

Abstract:
A method for treating a porous sheet material comprising at least one porous surface to render pore space thereof more hydrophilic, said method comprising contacting at least one porous surface of said sheet material with plasma under plasma treating conditions, wherein said plasma treating conditions comprise atmospheric pressure and plasma generating electrode frequency of greater than 5 MHz, wherein said porous sheet material is an extruded film comprising a surface layer of polyolefin and particles of a cavitating agent, wherein said layer has a meshed network of polyolefin fibers and striations of layers coplanar with the plane of the film, wherein said layer is porous in a direction perpendicular to the plane of the film and wherein said layer has a void content of at least 20%.