Published online by Cambridge University Press: 15 February 2011
Infiltration of preforms used to manufacture high-performance, advanced polymer composites can lead to void formation due to inhomogeneities within the preforms. Void formation occurs at three distinct length scales: the fiber, tow and part scales. Flow visualization experiments were used to characterize void formation at the tow and fiber scales. Effects of tow-scale inhomogeneities were studied by varying the warp angle of a woven fabric. Effects of fiber-scale inhomogeneities were studied using scale models of typical tows. The experiments indicate that minimization of void content requires a trade-off between fiberscale and tow-scale void formation.