Experimental Study on Silicone Rubber Mold Design for Thermal Expansion RTM

Abstract

The silicone rubber mold in thermal expansion resin transfer molding was used to generate high thermal expansion pressure on the preform, having an advantage over fabrication of complex-shaped composites. The mold thickness-fiber content equation was derived to design the mold size. It was established based on two parts in this article, the pressure and corresponding fiber content data obtained from compaction experiment and the mold thickness-pressure equation gained from the calculation theory for mold design. Considering the influence of process parameters on the mold size, the synergistic effect of temperature, mold thickness, and the fiber content has been analyzed. The results indicate that mold thickness is inversely proportional to the temperature when the desired fiber content remains constant. When the final fiber content of the part is set, every unit decrease in temperature leads to increasing amplitude of mold thickness. When the temperature variation is unchanged, with every unit increase in fiber content the amplitude of mold thickness grows larger. Moreover, according to the temperature inequality, the temperature variation should be above the critical value so as to make the mold designable.