MODEL FOR DETERMINING THE VENT LOCATIONS AND THE FILL TIME OF RESIN TRANSFER MOLDS

Simple models were developed for determining the vent locations and th e fill time of resin transfer molds containing thin flat preforms with isotropic permeabilities. The in-plane shape of the preform is arbitr ary and the preform may contain impermeable inserts. The vent location s required to avoid trapping air bubbles are determined by geometric c onsiderations. The time required to fill the mold is calculated by tre ating the resin flow inside the mold as partly radial and partly chann el-like flow. Tests were performed with different shape molds with and without inserts. The vent locations required to avoid air bubbles and the time required to fill the mold were determined. The experimentall y established vent locations were in good agreement with the vent loca tions given by the model. The measured and calculated hh times also ag reed well.