SB332: High-Temperature, Low‑Viscosity BMI Resin for Carbon‑Fiber Composites

Resins for Composite Materials

Samples for testing were obtained by vacuum infusion based on SB332 resin and carbon fabric (CF) 22508 (sateen 8H, 200 g/m2, 3K, 3.95 GPa).

Assemble the vacuum bag. Perform a leak test, the rate of the vacuum drop should not be more than 1 mbar per minute. The residual pressure in the bag must not be more than 10 mbar. Assemble the second vacuum bag, put airweave material between the layers of the vacuum film. Perform a leak test for the second vacuum bag. The residual pressure in the bag must not be more than 10 mbar. Degas for 20-30 minutes, at 100-120°C, at a pressure of no more than 10 mbar. During the degassing, the resin should be stirred intensively. Heat the tool up to 120-130°C. Maintaining the temperature of resin dispenser at 120°C, start the infusion process. After complete impregnation of the bag, close the resin inputs, but continue evacuation from the inner bag for at least 30 minutes. Then close the outputs from the inner bag. Maintain the outer vacuum bag until the end of curing process. Increase the temperature at a rate of 2°C/min to 160°C. Dwell at 160°C for 3 hours, heat to 190°C at a rate of 2°C/min, dwell at 190°C for 3 hours. It is possible to heat up to 190°C without exposure at 160°C, in the case that the auxiliary materials and mold materials withstand such conditions. Before removing the part, cool the mold to at least 90°C at a speed of no more than 5°C/min. Post-cure can be performed without tooling. Heat to 180°C at a rate of 2°C/min, from 180°C to 230°C, heat to 190°C at a rate of 0.5°C/min dwell 5 hours at 230°C. Do not cool faster than 5°C/min. For the measurement of vacuum, the use of absolute pressure sensors is recommended.