Unified saturation and micro-macro voids method in Liquid Composite Molding

The topic of this paper concerns void defects. We introduce a model to describe the macroscopic resin flow considering the compression of residual air in the preform. A microscopic flow model is also developed to account for the microvoid formation due to the variation of resin velocity at the flow front. According to these mathematical models, a numerical simulation code was developed to perform a combined macro and micro flow analysis with the saturation of the medium. The results of these simulations are compared with experimental results obtained by the laboratory device. We present the real-time measurement of the void content evolutions during the injection, using an original sensor. Our technique is based on the electrical conductivity of the injected liquid. After the material and method presentation, some results obtained during injection are shown. The developed analysis technique and the numerical simulation code can be used for obtaining the optimal processing conditions and design parameters in manufacturing of composites by Liquid Composite Molding (LCM) processes.