Patent ID: 9593436
Date: 2017-03-14
CPC Classifications: A01K,D01D,D01F,D02G,D02J,D04C,D06M

Claim:
1. A tapered multifilament yarn comprising a plurality of ultra-high molecular weight polyethylene filaments and not comprising metal particles or a synthetic resin coating, wherein the plurality of ultra-high molecular weight polyethylene filaments are tapered by a process comprising: subjecting an ultra-high molecular weight polyethylene filament to a tapering process comprising feeding the filament into a drawing apparatus wherein: a first portion of the filament is subjected to taking-over on the drawing apparatus at a take-over speed faster than a feed speed and thereby stretching and thinning the first portion of the filament, and a second portion of the filament is subjected to taking-over on the drawing apparatus at a take-over speed slower than a feed speed at a ratio of the take-over speed to the feed speed of not less than 0.5 and less than 1.0 under heating and thereby shrinking and thickening the second portion of the filament to a thickness greater than a thickness of the second portion of the filament prior to the tapering process, wherein a ratio of a cross section area of a thickest part to a cross section area of a thinnest part of the tapered multifilament yarn is not less than about 6.0, and wherein if the ultra-high molecular weight polyethylene filament is subjected to a drawing process prior to the tapering process, then a value η of the tapered filament equal to (highest take-over speed to the feed speed ratio of the tapering process)/(lowest take-over speed to the feed speed ratio of the tapering process) is not more than 0.8 times a value η of a tapered filament which is not subject to a drawing process prior to the tapering process.