Patent ID: 6905563
Filing Date: 2005-06-14
Classification: D04H,E04B,Y10T

Abstract:
1. A method for manufacturing an encapsulated fiber batt comprising the steps of: conveying a fiber batt in a first direction, the fiber batt having n surfaces; providing a molten polymeric material and a blowing gas to a plurality of melt blowing heads, at least one melt blowing head being arranged adjacent each of the n surfaces of the fiber batt; forming a plurality of polymeric filaments by ejecting a stream of the molten polymeric material from a first opening provided in each of the melt blowing heads toward the surface of the fiber batt adjacent each of the melt blowing heads; forming a plurality of hot polymeric fibers by contacting each of the polymeric filaments with a gas stream of the blowing gas from a second opening provided in each of the melt blowing heads, the velocity, volume and direction of the gas stream acting to attenuate and separate portions of the polymeric filaments, the hot polymeric fibers having a diameter of between about 1 and about 9 microns; accumulating a randomly oriented layer of the hot polymeric fibers on each of the n surfaces of the fiber batt, the temperature of the hot polymeric fibers reaching each of the n surfaces of the fiber batt being sufficient to induce fiber-to-fiber adhesion between the hot polymeric fibers; and cooling the layers of hot polymeric fibers to form a substantially continuous nonwoven polymeric skin layer on each of the is surfaces of the fiber batt and thereby encapsulate the fiber batt; wherein: the fiber batt comprises first and second major surfaces and first and second minor surfaces; and further wherein: the substantially continuous nonwoven polymeric skin layer formed on the first major surface has a substantially different weight per unit area than the substantially continuous nonwoven polymeric skin layer formed on the second major surface or the substantially continuous nonwoven polymeric skin formed on the first and second minor surfaces.