Method for Manufacturing Shaped Product with Maintained Isotrophy

摘要

The present invention provides a method for manufacturing a shaped product constituted by a fiber-reinforced composite material including reinforcing fibers and a thermoplastic resin. The shaped product maintains isotropy of the fibers to the end thereof even if press-molded under conditions in which charge ratio of a prepreg to a die is low. Specifically, the method includes using a specific prepreg obtained by impregnating the reinforcing fibers with thermoplastic resin, and molding-processing the prepreg under specific conditions.

主权项

1. A prepreg comprising:
reinforcing fibers having an average fiber length of 5 mm to 100 mm; and a thermoplastic resin, wherein the reinforcing fibers are substantially two-dimensionally randomly oriented at a fiber areal weight of 25 g/m2 to 10000 g/m2,
reinforcing fiber bundles (A) constituted by the reinforcing fibers of a critical single fiber number or more, the critical single fiber number being defined by equation (1), are included in an amount of 20 Vol % or more and less than 99 Vol % with respect to the total amount of the reinforcing fibers in the prepreg, an average number of the reinforcing fibers (N) in the reinforcing fiber bundles (A) satisfies equation (2):
Critical single fiber number=600/D   (1)0.7×104/D2