Mechanism of Void Formation in Composite Processing with Woven Fabrics

A mechanism for void formation is suggested, involving an analysis of the resin flow at macro and micro levels. Both these types of flow arise from the characteristic structure of woven fabrics. In order to investigate the mechanism of void formation in woven fabrics, a new dimensionless number was defined as the ratio of the superficial velocity to the initial spreading rate. The prediction of void formation using this dimensionless number had a good correlation with the results from the cross sectional observation and void content measurement. It was confirmed that the mechanism introduced in this study is very desirable and that the morphological structure of the woven fabric plays a key role in void formation.