Patent ID: 9211654
Filing Date: 2015-12-15
Classification: B29B,B29C,Y10T

Abstract:
1. A manufacturing method of a continuous fiber-reinforced thermoplastic resin pellet having a rod-shaped configuration with a circular cross section, consisting of: preheating a long reinforcing fiber bundle, impregnating the preheated long reinforcing fiber bundle with molten thermoplastic resin and pultruding and twisting the resin-impregnated reinforcing fiber bundle with a single pair of oppositely disposed metal twisting rollers with rotating shaft lines which are crossed in the vertical plane and parallel in the horizontal plane, which single pair of rollers both pultrudes and twists the continuous fiber-reinforced resin strand running in between, followed by cutting of a rod-shaped composition formed of the twisted resin-impregnated reinforcing fiber bundle by a specific length, wherein: a bundle of mono-filament fibers having a diameter of 4 to 30 μm is present as the reinforcing fiber bundle; the number of the mono-filament fibers is set so that the reinforcing fiber bundle is impregnated with the molten thermoplastic resin for a volume filling ratio V the resin-impregnated reinforcing fiber bundle is pultruded with twisting by setting a twisting angle of the twisting rollers so that a twisting pitch P given by P=L/d (where L is a traveling length of a twist in the rod-shaped composition longitudinal direction per rotation of the rod-shaped composition, and d is a diameter of a circle comparable to an area of the rod-shaped composition cross section) falls within a range of 2.5 to 36 (m/rev·m), so that a thickness of a peripheral surface resin layer is adjusted corresponding to the number of the mono-filament fibers and the diameter of a circle comparable to an area of the rod-shaped composition cross section; wherein the twisting angle is set so that when the volume filling ratio V wherein the diameter d of a circle comparable to an area of the rod-shaped configuration with a circular cross section ranges from 1.0 to 4.0 mm and the length of each fiber-reinforced thermoplastic resin pellet ranges from about 3 to 10 mm.