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. 28, 1990
Filed:
Feb. 10, 1989
E. I. du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
Uniformity of properties of spun polyamide filaments is improved by treating flake polyamide with successive nitrogen gas streams, the first having a variable temperature and water content, and the second being dry but having a variable flow rate. Viscosity of the molten polyamide from a melter for the flake is determined by measuring differential pressure across a transfer pipe. The viscosity measurement is used by automatic control apparatus to control the flow rate of the second stream, and the moisture content of a make-up stream added to the first stream. The flow rate of the make-up stream is controlled to maintain the second stream within limits, and the temperature of the first stream is controlled to maintain the flow rates of the make-up and second streams within limits.