Abstract: To study the fiber spreading process of carbon fiber by airflow, a set of airflow fiber spreading device has been developed. The effects of airflow velocity, support roller span, and fiber overhang on fiber spreading width were studied through multiple orthogonal experiments, and the experimental results were analyzed. The MATLAB digital image processing technology was used to preprocess the unfolded carbon fiber image, including reduction, grayscale, and image enhancement. The coefficient of variation and probability distribution were introduced to characterize the uniformity of the transverse and longitudinal distribution of carbon fibers. The results show that there is a linear positive correlation between the width of air flow fiber expansion and the fiber overhang within a certain range. Choosing the optimal process parameters of air flow velocity of 4 m/s and support roller span of 140 mm has a good fiber spreading effect. The digital image analysis method can better characterize the uniformity of carbon fiber airflow and is consistent with experimental results, which has good industrial application prospects.

Key words: carbon fiber, airflow fiber spreading, orthogonal test, image processing, uniformity