Patent ID: 8329280
Filing Date: 2012-12-11
Classification: B29C,C03B,C03C,C08J,Y02P,Y10T

Abstract:
1. A chopped fiber bundle comprising: (a) reinforcing fibers unidirectionally arranged and a bundling agent which bundles said reinforcing fibers, wherein (b) the length of each of said reinforcing fibers is 5 to 100 mm, (c) said chopped fiber bundle has a first transition section in which the number of said reinforcing fibers in a cross section of said chopped fiber bundle perpendicular to the arranging direction of said reinforcing fibers increases from a first tip which is one in the arranging direction of said reinforcing fibers toward a second tip which is another tip and also has a second transition section in which the number of said reinforcing fibers in a cross section of said chopped fiber bundle perpendicular to the arranging direction of said reinforcing fibers increases from said second tip toward said first tip, (d) said chopped fiber bundle has a constant section located between said first transition section and said second transition section in the arranging direction of said reinforcing fibers, wherein the number of reinforcing fibers in the cross section of the fiber bundle in said constant section is constant in the arranging direction of said reinforcing fibers, and wherein one end face of said constant section coincides with a first terminal end face of said first transition section which is at an opposite end of said first tip while another end face of said constant section coincides with a second terminal end face of said second transition section which is at an opposite end of said second tip, or wherein said first terminal end face directly coincides with said second terminal end face, (e) a change of the total cross-sectional area of said reinforcing fibers in the cross section of said chopped fiber bundle per 1 mm in the arranging direction of said reinforcing fibers between said first tip and said second tip is 0.05 mm (f) all of said reinforcing fibers have the same length.