Carbon-fiber preform and carbon-fiber-reinforced plastic

Abstract

According to the present invention, a carbon-fiber preform for a carbon-fiber-reinforced plastic is formed from mutually intersecting warp and weft each of which including a carbon-fiber multifilament yarn. At least one of layer surfaces has fluff formed by cutting some of filaments of the carbon-fiber multifilament yarn, and a total fluff length of fluff formed on the warp and a total fluff length of fluff formed on the weft are not equal. The present invention provides a CFRP in which the delamination strength (interlaminar shear strength) is improved and that has a high strength.

1 . A carbon-fiber preform for a carbon-fiber-reinforced plastic, the carbon-fiber preform being formed from mutually intersecting warp and weft each of which including a carbon-fiber multifilament yarn,
 wherein at least one of layer surfaces has fluff formed by cutting some of filaments of the carbon-fiber multifilament yarn, and a total fluff length of fluff formed on the warp and a total fluff length of fluff formed on the weft are not equal.   
     
     
         2 . The carbon-fiber preform according to  claim 1 , wherein a total fluff length with respect to a direction of one of the warp and the weft is less than 20% of a sum of the total fluff lengths of the warp and the weft. 
     
     
         3 . A carbon-fiber-reinforced plastic produced by layering a plurality of carbon-fiber preforms for a carbon-fiber-reinforced plastic, each of the carbon-fiber preforms being formed from mutually intersecting warp and weft each of which including a carbon-fiber multifilament yarn,
 wherein at least one of layer surfaces of at least one of the plurality of carbon-fiber preforms has fluff formed by cutting some of filaments of the carbon-fiber multifilament yarn, and a total fluff length of the fluff formed on the warp and a total fluff length of the fluff formed on the weft are not equal, and   wherein the at least one of the plurality of carbon-fiber preforms is layered so that one of the warp and the weft having a smaller total fluff length forms an angle of 45° or less with respect to a direction in which strength is required for the carbon-fiber-reinforced plastic.   
     
     
         4 . The carbon-fiber-reinforced plastic according to  claim 3 , wherein a sum of total fluff length of the carbon-fiber preform on which the fluff is formed with respect to the direction in which strength is required for the carbon-fiber-reinforced plastic is less than 20% of a sum of the total fluff lengths of the warp and the weft. 
     
     
         5 . The carbon-fiber-reinforced plastic according to  claim 3 , wherein the total fluff length of one of the warp and the weft of the carbon-fiber preform on which the fluff is formed is less than 20% of a sum of the total fluff lengths of the warp and the weft, and
 wherein the carbon-fiber preform is layered so that the one of the warp and the weft is oriented in the direction in which strength is required for the carbon-fiber-reinforced plastic.