Numerical investigation on complete filling process in pre-compacted preform vacuum infusion

The pre-compacted preform vacuum infusion (PPVI) is a variation of the vacuum-assisted resin transfer molding (VARTM) process. The technology additionally leverages the elasticity of the vacuum bag during infusion, enabling the resin infusion pressure to exceed one atmospheric pressure and thereby reducing the infusion time. The PPVI effectively reduces the total filling time and resin waste through the use of partial infusion strategy and the two-sided drainage. The effects of four process parameters, including the spring modulus of the vacuum bag, resin infusion pressure, infusion strategy, and preform characteristics, on the filling process and resin waste are investigated. Numerical results show that when a high infusion pressure or a small spring modulus of the vacuum bag is employed, the infusion time can be reduced to an extent that is greater than the increase in post-infusion time. Consequently, both can reduce the total filling time at the expense of resin consumption. However, a high infusion pressure must be applied together with the appropriate elasticity of the vacuum bag to avoid its over-inflation. A partial infusion strategy can be employed to reduce resin waste, but its effectiveness in decreasing total filling time depends on the preform characteristics. Although the process factors are interrelated, this work attempts to present the optimal condition where both total filling time and resin consumption are considered.