Large tow carbon fibers (12K and 50K) are spreaded on a self-designed multi-rollers system within several special-shaped rollers as kernel parts. And effect of spreading process on the permeability characteristics of large tow carbon fi ber

on the inner structure and bending performance of large tow carbon fi ber reinforced composites are studied. Results show both 12K and 50K large tow carbon fibers can be spreaded ideally by using self-designed spreading system. Thanks to thinner thickness of fi ber tow

the uniformity of fi ber distribution in perform is improved

the permeability of perform is decrease to half

and the uniformity of permeation is improved. There are less internal defects and smaller internal defects in spreaded large tow carbon fi ber reinforced composites

and more uniformity of fi ber-resin distribution is obtained. The bending performance such as bending modulus and bending strength of composites are improved

and the discrepancy of performance of composite is smaller.