Study on the Measurement of Fiber Orientation During Press Molding of Long Fiber-Reinforced Thermoplastic Composites Using Counting Method

For the object with oriented fiber mat, which is difficult to identify, image processing with soft X-ray based on pixel gradation is used to calculate the orientation angle. During the estimation of oriented fiber, intensity method from pixel intensity is adopted. To verify its confidence level, counting method for single fiber count on orientation is proposed. According to this study, average gradient of fiber orientation angle is 0.94 for intensity method, and 0.98 for counting method. Accuracy of the latter is higher than the former by about 4%. During press molding, fiber orientation function (J), which depicts the state of fiber orientation for long fiber is not affected by fiber content, compression speed, and molding temperature. However, compression molding shows the higher fiber orientation function (J) along with compression ratio, and fiber orientation is anisotropic.