The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 21, 1992
Filed:
Oct. 20, 1989
Thomas R Clark, III, Hixson, TN (US);
Joseph A Cofer, Jr, Hixson, TN (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
A yarn comprised of a polyamide which is at least about 85% poly(hexamethylene adipamide) or poly(.epsilon.-caproamide) is disclosed which has a relative viscosity of greater than about 50, a tenacity of greater than about 11.0 g/d, a dry heat shrinkage at 160.degree. C. of not more than about 6.5 percent, a boil-off shrinkage of less than about 7%, a modulus of greater than about 35 g/d, a birefringence of greater than about 0.060, a differential birefringence D: .DELTA..sub.0.90-0.00, of greater than 0, and a sonic modulus of greater than about 90 g/d. The process for making the yarn includes drawing of a feed yarn while heating to at least about 185.degree. C. in at least a final draw stage to a draw tension of at least 3.8 g/d, subsequently decreasing the tension while heating to at least about 185.degree. C. to produce a length decrease of between about 2 and about 13.5, and cooling and packaging the yarn.