Patent ID: 6176952
Filing Date: 2001-01-23
Classification: D04H

Abstract:
A method of making an improved meltblown fibrous layer characterized as having:(a) a hydrohead performance at least 16.5 percent greater than the hydrohead of a first meltblown layer,(b) a basis weight less than 67 g/m.sup.2 and equal to or less than the basis weight of the first meltblown layer, and(c) a water or moisture vapor transmission rate within at least 88 percent of the first meltblown layer,the method comprising(i) providing the first meltblown layer,(ii) separately secondarily processing the first meltblown layer at an elevated temperature, an elevated pressure and a residence time which equates to a roll speed of less than 20 feet/minute (6.1 m/min.) to effectuate the improvement, and(iii) collecting the improved meltblown layer.