화학공학소재연구정보센터
Polymer Engineering and Science, Vol.36, No.7, 953-962, 1996
Effect of Compression Process on Void Behavior in Structural Resin Transfer Molding
To realize low void content molded parts, we propose structural resin transfer molding (SRTM) with the compression process. Resin was injected with a gap height between the upper and lower halves of matched metal dies. Mold filling was performed by a squeezing motion of the upper mold die. The usefulness of the compression process was examined by comparison to a conventional SRTM method. Void distribution and bending properties in both processes were compared. The SRTM method with compression was better at driving out voids. The effects of the gap height between the upper and the lower halves of the molds and of the gap closure rate during mold closing after injection on the void distribution were examined. The gap height did not affect the void distribution. When the gap closure rate was high, the voids were expelled towards the end of cavity, whereas voids remained on the top surface of the molded parts using a small gap closure rate. The difference in void behavior due to the gap closure rate was determined by a balance of the permeability between the flow and the transverse directions.