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US 3,944,386 AGranted
Process for dyeing filaments of acrylic polymer
AssigneeE. I. Du Pont de Nemours and Company
InventorWilliam Kenneth Wilkinson
Life of this patent
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Abstract
A process is disclosed for dyeing a bundle of dry-spun acrylonitrile polymer filaments before the solvent remaining after the spinning step has been extracted. The filaments having a water content of not over 30%, are subjected to a dye bath, and drawn while immersed in the bath at least 1.5.times. and are then washed to rinse them and to extract spinning solvent.
Claims4
A process for dyeing filaments of dry-spun acrylic polymer which comprises, in sequence, the steps of
- 1. dry-spinning a solution of acrylonitrile polymer to form undrawn filaments containing from about 10 to 50 percent by weight of spinning solvent,
- 2. moistening the spun filaments to have a water content of not over 30 percent by weight,
- 3. contacting the moist, solvent-containing, undrawn filaments with liquid dye by immersing them in a liquid dye bath,
- 4. drawing the filaments at least 1.5.times. while they are still immersed in the dye bath, and
- 5. immersing the filaments in a hot aqueous bath to rinse the filaments and extract spinning solvent from them.
2 more elements
Dependencies are inferred from the claim text.