Analysis of resin transfer/compression molding process

TLDR

Resin transfer/compression molding (RT/CM) is a two‑step process that injects resin and then closes the mold, improving resin flow speed, fiber volume fraction, and reducing filling time. The study aims to develop a simulation program for the mold‑filling phase of RT/CM using a modified control‑volume finite‑element method combined with a fixed‑grid approach. The numerical code predicts resin flow, temperature, pressure, cure distribution, compression force, and speed, and was validated against experiments on a complex 3‑D shell, with further simulations exploring anisotropic permeability and higher fiber volume fractions. Experimental results closely matched the numerical predictions, confirming the accuracy of the simulation for resin front location and overall process behavior.

Abstract

Abstract Resin transfer/compression molding (RT/CM) is a two‐step process in which resin injection is followed by mold closing. This process can enhance the resin flow speed and the fiber volume fraction, as well as reducing the mold filling time. In this study, a simulation program for the mold filling process during RT/CM was developed using the modified control volume finite element method (CVFEM) along with the fixed grid method. The developed numerical code can predict the resin flow, temperature, pressure, and degree of cure distribution during RT/CM. The compression force required for squeezing the impregnated preform can also be calculated. Experiments were performed for a complicated three‐dimensional shell to verify the feasibility of the RT/CM process and the numerical scheme. The compression force and the compression speed were measured. A close agreement was found between the experimental data and the numerical results. The resin front location obtained from a short shot experiment was compared with the numerical prediction. Again, a close agreement was observed. In order to demonstrate the effectiveness of the numerical code, simulations were performed for more complicated process conditions with anisotropic permeability of the preform at higher fiber volume fractions.