PROCESS FOR FORMING LIQUID IMPERMEABLE SHEET MATERIAL HAVINGA FIBROUS SURFACE AND PRODUCTS FORMED THEREBY

摘要

Disclosed are a number of processes for forming a liquidimpermeable sheet having a fibrous cloth-like surface. In one embodiment the process includes the steps of: (1) forming a sheet having first and second fibrous surfaces; and subjecting the sheet to pressure and a z-gradient temperature differential sufficient to melt the fibers of the first surface and form the melt into a liquid impermeable skin without significantly altering the fibers of the second surface. In another embodiment, the process includes the steps of: (1) forming a sheet having first and second fibrous surfaces wherein, upon the sheet being subjected to a sufficient temperature, the fibers forming the first fibrous surface are adapted to substantially completely melt prior to the fibers forming the second fibrous surface significantly melting; and (2) subjecting the sheet to a sufficient pressure and temperature to melt the fibers of the first surface and form the melt into a liquid impermeable skin without significantly altering the fibers of the second surface. In some embodiments the liquid impermeable skin is subsequently apertured to make the sheet breathable. Products formed by these processes are also disclosed.