Patent ID: 6114017
Filing Date: 2000-09-05
Classification: D01D,D04H,Y10T

Abstract:
A method for manufacturing a nonwoven web which comprises:melting a polymer by polymer heating and extrusion means;extruding said polymer at flow rates of less than 1 gram per minute per hole through the polymer orifices of one or more modular dies, each of said dies consisting of two or more spaced apart cross directional rows of polymer orifices, wherein the diameters of said polymer orifices of each individual row are constant diameter and wherein each successive row of said polymer orifices has a smaller diameter, said die being heated by a heating means; andblowing said polymer extrudate, using heated air of at least 200.degree. F. or more, from 2 or more air jets per polymer orifice, wherein said air jets may have a constant or a variable cross-section, to produce essentially continuous polymer filaments wherein said continuous polymer filaments from each row on the die have different and increasingly smaller diameters than the preceding rows, and depositing said fiberized polymer on a collecting means to form a self bonded web consisting of as many layers of disbursed continuous polymer filaments as the number of rows in the die wherein each layer consists of filaments having a different and smaller diameter resulting in a filament size gradient through its depth.