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:
Aug. 14, 1979
Filed:
Feb. 22, 1978
Akio Kimura, Ibaraki, JP;
Osamu Wada, Takatsuki, JP;
Michikage Matsui, Ibaraki, JP;
Kiyotaka Ozaki, Ibaraki, JP;
Teijin Limited, Osaka, JP;
Abstract
The present invention relates to a method of producing a twisted polyester filament yarn having a high level of twist used for a woven or knitted crepe fabric. A method of this invention comprises imparting a high level of twist to a polyester filament yarn which has particular properties, and heat setting said twisted polyester filament yarn. The first of these properties which the polyester filament yarn has is that a boil-off shrinkage in boiling water is in the range of 0% to 5%. The second is that a thermal shrinkage stress at 140.degree. C. in hot air is more than 0.03 g/de. The third is that a ratio of a thermal shrinkage stress at 180.degree. C. in hot air to a thermal shrinkage stress at 140.degree. C. is more than 1.0. The polyester filament yarn which has above mentioned properties can be obtained by repeating heat treatment several times at a temperature from 160.degree. C. to 220.degree. C. in hot air, stretching the polyester filament yarn in a range of 2% to 10% and successively shrinking it in the same range, or by being subjected to heat treatment at a temperature from 160.degree. C. to 220.degree. C. in hot air, shrinking restrictively the polyester filament yarn in a range of 0% to 10% under the relaxed state.