MOLDING OF COMPLEX COMPOSITE PARTS UTILIZING MODIFIED SILICONE-RUBBERTOOLING

Control of the pressure at the core temperature of polymer matrix comp osites is critical to the fabrication of high quality composite struct ures. Cast silicone rubber has been utilized as a tooling aid to apply pressure to complex composite parts during cure. Due to the high expa nsion rates of most silicone rubber systems in the ''as received'' for m if is very difficult to achieve proper pressure application levels a t the cure temperature. This study focused on selective addition of si lica powder to Aircast 3700 castable silicone rubber. The addition of 5% silica reduced the expansion rate by a factor of 10 compared to ''a s received'' Aircast 3700. This allows very accurate selected pressure levels to be applied at composite core temperatures. Governing formul as and experimental test results from silica modified Aircast 3700 cas table silicone robber are presented herein.