Patent ID: 7931457
Filing Date: 2011-04-26
Classification: B29C,D01D,D04H,Y10S,Y10T

Abstract:
1. An apparatus for forming fibers of sub-micron size, comprising: first and second opposing walls defining a gas passage, of which at least one of the walls is heatable, wherein said gas passage being operable to receive pressurized gas from a pressurized gas source and to conduct the pressurized gas as a gas stream in an upstream to a downstream direction within the first and second opposing walls, wherein said gas passage comprises a first, upstream section into which the gas enters from a supply end, a transition region, and a second, downstream section in which the gas flows to an exit end, wherein the transition region fluidly connects the first section to the second section, and the gas passage ends at the exit end of the second section, and wherein said first section of the gas passage having a decreasing cross-sectional area from the supply end to the transition region, and said second section of the gas passage having an increasing cross-sectional area from the transition region to the exit end of the second section; at least one bounded polymer passage operable to receive molten polymer from a polymer extruder and to conduct the molten polymer as at least one flowable polymer fluid stream to at least one of said walls that is heatable in the gas passage, wherein the polymer passage ends in at least one polymer passage opening in at least one of said opposing walls that is heatable, wherein each said opening is operable to extrude polymer fluid stream in the form of a film onto a heatable wall wherein the film is joinable with the gas stream of the gas passage to fibrillate the polymer film to form fibers comprising sub-micron fibers that exit from the exit end of said second section of the gas passage.