Patent ID: 6395216
Filing Date: 2002-05-28
Classification: B05B,B29C,D01D,F02M,F23D

Abstract:
A method of forming a fiber from a thermoplastic polymer, the method comprising:supplying a molten thermoplastic polymer; extruding the molten thermoplastic polymer through an extrusion orifice in a die assembly to form a threadline, the die assembly comprising: a die housing defining: a chamber adapted to receive the molten thermoplastic polymer; an inlet orifice adapted to supply the chamber with the molten thermoplastic polymer; and an extrusion orifice adapted to receive the molten thermoplastic polymer from the chamber and extrude the polymer; and a means for applying ultrasonic energy to a portion of the molten thermoplastic polymer, which means for applying ultrasonic energy is located within the chamber partially surrounded by the molten thermoplastic polymer, and is adapted to apply the ultrasonic energy to the molten thermoplastic polymer as it passes into the extrusion orifice; exciting the means for applying ultrasonic energy with ultrasonic energy while extruding the molten thermoplastic polymer; and attenuating the threadline to form a fiber.