Patent ID: 6478996
Filing Date: 2002-11-12
Classification: D01D,D01F

Abstract:
A method of producing a highly oriented yarn from a thermoplastic material, comprising the steps ofextruding a melted thermoplastic material through a nozzle to form a plurality of downwardly advancing filaments, and such that the filaments solidify at a location spaced below the nozzle, withdrawing the filaments under a withdrawal tension so as to cause the filaments to be drawn while being solidified, with the withdrawal tension being generated by a withdrawal speed of at least about 6,500 m/min, and assisting the filaments in their advance before their solidification with help of an airflow while passing the filaments through a constrictor and a diffuser that are interconnected by a seam at the most narrow cross-section such that before their solidification the filaments are relieved from tensile stress and during solidification and drawing a reduced withdrawal tension is effective on the filaments, wherein shortly downstream of the seam the filaments solidify.