Process for uniformly drawing polyethylene terephthalate filaments to form high shrinkage fibers
AssigneeImperial Chemicl Industries, Ltd.
InventorsGeoffrey Marshall, Eric Ivan Riseley
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Abstract
A process for uniformly drawing tows of poly(ethylene terephthalate) to produce high shrinkage fibres wherein the drawing is effected with the tow in a hot water saturated condition at a controlled birefringence, temperature and draw ratio. The product has initial shrinkages (as defined) of at least 5% and a high uniformity.
Claims10
A process for uniformly drawing a tow of poly(ethylene-terephthalate) filaments to form high shrinkage fibers comprising passing a tow at least partly around the peripheries of a plurality of feed rolls in series and a plurality of draw rolls in series the latter rotating at a higher peripheral speed, characterised in that the tow in contact with more than one of the feed rolls is sprayed with a saturating amount of aqueous liquid at a temperature of 60.degree. - 80.degree.C., the filaments comprising the undrawn tow have an intrinsic viscosity of 0.3 to 0.75 and a mean birefringence of 2 .times. 10.sup.-.sup.3 to 9 .times. 10.sup.-.sup.3 and a draw ratio of 2.0:1 to 3.3:1 is applied such as to give drawn filaments having an initial shrinkage in 70.degree.C. water under a load of 0.011 grams per decitex of at least 5%.
Dependencies are inferred from the claim text.