Abstract: In order to overcome the instability and control difficulty of the chopping process of carbon fibers (CFs),the process parameters affecting the quality of chopped CFs were investigated.By taking the oven tempera- ture,the press roll pressure,the cutter roll pressure and the chopping speed as the evaluation factors and by using the length dispersion,the width uniformity,the fracture section uniformity and the fracture surface morphology as the quality evaluation indexes,some orthogonal experiments were designed and carried out,from which the evalua- tion weight of each quality evaluation index was determined based on the entropy theory.Moreover,the chopping process parameters were evaluated via a fuzzy comprehensive evaluation.The results show that the CFs with the best quality can be chopped at an oven temperature of 150℃,a press roll pressure of 0. 2MPa,a cutter roll pressure of 0. 4MPa and a chopping speed 6. 9m/min.

Key words: chopped carbon fiber, quality evaluation, orthogonal experiment, entropy, fuzzy comprehensive evaluation