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:
Dec. 22, 2009
Filed:
Dec. 14, 2004
Tatsuo Kobayashi, Fukushima-Ken, JP;
Naohiro Sonobe, Fukushima-Ken, JP;
Tatsuo Kobayashi, Fukushima-Ken, JP;
Naohiro Sonobe, Fukushima-Ken, JP;
Kureha Corporation, Tokyo, JP;
Abstract
A pitch-based carbon fiber sliver providing a high-strength carbon fiber spun yarn is efficiently produced by providing a pitch-based carbon fiber mat comprising a mass of piled-up pitch-based carbon fibers of which fiber extension directions are aligned preferentially in one direction; and directly subjecting the carbon fiber mat to drawing and carding by means of a carding machine while moving the mat in said one preferential alignment direction. The thus-obtained carbon fiber sliver is drawn and twisted to produce a pitch-based carbon fiber spun yarn containing at least 3 wt. % of fibers having a fiber length of at least 150 mm, a number of primary twist of 50-400 turns/m and a tensile strength of at least 0.10 N/tex.