The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 02, 1999
Filed:
Jun. 02, 1997
Raimund Schwarz, Tomils, CH;
Werner Stibal, Chur, CH;
Ems-Inventa AG, , CH;
Abstract
The present invention pertains to a process for the production of a polyester multifilament yarn having at least 90 mol % ethylene terephthalate with a single filament titer of 1 to 20 dtex, using a central quenching system, characterized in that the method has the following steps: Extrusion of a polyethylene terephthalate polymer melt through a spinneret that has a number of capillaries between 150 and 1500, adjusting a spacer length between 5 and 150 mm, cooling of the obtained threads by means of a constant blown-air speed profile defined in the thread transit direction in that it initially rises very quickly in the region facing the spinneret, then reaches a maximum and subsequently drops off initially very quickly, then more slowly, with the average blown air speed in the vicinity of the threads being between 0.15 and 1.5 m/sec, in such a manner that the undrawn yarn produced from the process has a birefringence of between 0.050 and 0.130, and the coefficient of variation in tenacity at break between the undrawn, single filaments of a yarn amounting to a maximum of 6% with the coefficient of variation in the elongation at break amounting to a maximum of 8%, whereby finally the undrawn yarn is further processed into a finished yarn.