ROHACELL® RIST is a closed-cell rigid foam based on polymethacrylimide (PMI) chemistry, which does not contain any CFC's. We have specially developed ROHACELL® RIST for use as a structural core in connection with vacuum infusion processes. Its mechanical and thermo-mechanical properties are similar to those of ROHACELL® WF. Its cell size, however, represents an optimal compromise between low resin uptake—about 50% less than for ROHACELL® WF—and satisfactory bonding of the facings to the foam core. Its optimized cell structure makes ROHACELL® RIST particularly suitable for vacuum infusion and RTM processes, where it can be used at temperatures of 130°C and up to a pressure of 0.7 MPa. Heat treated ROHACELL® RIST-HT allows safe and stable processing at a temperature of 180°C with pressures of up to 0.7 MPa.Information provided by Evonik |