Manufacture of high-quality chopped carbon fibers based on fuzzy comprehensive evaluation

Chopped carbon fiber, as a commercially available category of carbon fiber, is an important intermediate material to fabricate carbon fiber-reinforced composites or nonwoven fabrics. Due to lack of direct quality assessment method, the quality of chopped carbon fibers is always indirectly evaluated by its composites or fabrics. Here, we employed an entropy-weighted fuzzy comprehensive evaluation method to directly assess the quality of chopped carbon fibers in mass production. Considering chopped carbon fibers with good quality should appear in the forms of good length uniformity, well bundling appearance, good surface properties, and identical fracture, four evaluation indexes were selected, including length standard deviation, width dispersion standard deviation, average scores of fracture morphology, and bundling morphology. Among which, both the fracture morphology and bundling morphology were scored by an expert scoring method. Furthermore, we established an orthogonal test consisting of four factors and three levels with the aim of reducing experiment frequency. The results indicated that the optimal processing parameters were obtained through the calculation of fuzzy comprehensive evaluation, thus fabricating high-quality chopped carbon fibers. This work can have a certain guidance value for the mass production of chopped carbon fibers in the industry.