Birch, Stewart, Kolasch & Birch, LLP
Process of making polyester filamentary yarn for tire cords
Polyester multi-filamentary yarn, useful as tire reinforcement, is produced by melting polyester resin at 290&deg; C. or below including at least 90 mol % of polyethylene terephthalate with intrinsic viscosity of 0.7-1.2; filtering the molten resin for filtering retention time of ten minutes or below; spinning the filtered, molten resin by extrusion through a nozzle which has 250-500 holes, each ranging in diameter from 0.5 mm to 1.2 mm with a length/diameter ratio from 2 to 5; primarily quenching the extruded yarn at a temperature of 100-195&deg; C. in a zone of 50 mm or more distance directly below the nozzle; secondarily quenching the yarn with air at its glass transition temperature (Tg) or below; taking off the yarn at spinning stress of 0.3 g/d or greater; drawing taken-off yarn at total draw ratio of 1.3 or greater; and thermally treating the yarn at temperature 150-230&deg; C.
Kolon Industries, Inc.
Y B D Y D Y
Y10T B60C D02G Y10T D02G Y10T
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Sung Joong Seung Oh Gi Woong
Kim Lee Kim