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US 4,009,511 AGranted
Process for drawing polyamide monofilaments
AssigneeE. I. Du Pont de Nemours and Company
InventorSibbley Paul Gauntt
Life of this patent
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Abstract
Heavy denier, polyamide monofils are produced by the coupled steps of spinning, quenching, drawing and winding. Quenching involves passage of the filament through an air gap and a water bath. There are two stages of drawing. In the first stage, pressurized steam is used to deorient surface polymer and as a draw assist.
Claims9
In a process including the coupled steps of spinning, quenching and drawing a heavy denier, aliphatic polyamide monofilament in first and second draw stages to a total draw ratio of at least 5.5.times., the improvement comprising:
- water-quenching the monofilament, advancing the quenched monofilament, in said first draw stage through a pressurized, surface-plasticizing, steam atmosphere wherein it is orientation-stretched at a ratio of at least 3.5.times., and then
- advancing the monofilament, in said second draw stage through a zone heated with a radiant heater at a temperature of 700.degree. C.-1300.degree. C. wherein it is orientation-stretched at a ratio of at least 1.3.times..
Dependencies are inferred from the claim text.