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US 4,064,214 AGranted
Process for making polytetrafluoroethylene yarn
AssigneeE. I. Du Pont de Nemours and Company
InventorEmerson B. FitzGerald
Life of this patent
Estimating the term…
Abstract
A process for forming polytetrafluoroethylene yarn by 1. forming an oriented polytetrafluoroethylene film by drawing a sintered sheet from about 5 to 30 times its original length at an elevated temperature; and 2. passing the oriented film through fibrillating means such as a high turbulent air velocity jet to form a yarn of entangled irregular shaped non-uniform staple fibrils. The yarn and woven, non-woven and knitted fabrics prepared from this yarn also are part of the invention.
Claims4
A process for forming a polytetrafluoroethylene yarn which comprises
- 1. forming an oriented film consisting of polytetrafluoroethylene having a tensile strength of 50,000-100,000 pounds per square inch by drawing a sintered polytetrafluoroethylene sheet at a temperature of about 340.degree.-400.degree. C. from about 5 to 30 times its original length;
- 2. passing the oriented film through a fibrillating means comprising a jet through which a high velocity fluid is passed and is impinged upon the oriented film thereby forming a yarn of entangled irregularly shaped non-uniform staple fibrils.
Dependencies are inferred from the claim text.