FIBER REINFORCED RESIN COMPOSITION

PURPOSE: To uniformly distribute reinforcing fibers in high density by setting the content of the reinforcing fibers in a fiber reinforced resin compsn. to a specific value and measuring the area ratio of the reinforcing fibers in the fiber reinforced resin compsn. by a specific evaluation method to set the irregularity thereof to a standard deviation specific value. CONSTITUTION: The content of the reinforcing fibers in a fiber reinforced resin compsn. is 60-90vol.%. The sample of the fiber reinforced resin compsn. is pushed in an acrylic resin to be cured for 20min at room temp. and the cross section vertical to the orientation direction of the reinforcing fibers is exposed by grinding. The exposed surface is successively ground for one min by SiC wet papers with yarn counts of 220, 500, 1000, 2400 and subsequently ground for 1.5min by diamond slurries with average particle sizes 6, 1μm and SEM image of each of the ground surfaces is photographed. Each of cross section photographs is demarcated so as to obtain square units a40-100 with an equal area not overlapped with each other and peripheral edge parts (b) are removed to perform image processing and the area ratios of reinforcing fibers S in the square units are calculated to be set to polulation to set irregularity to 10% or less in standard deviation.