Molding process: the mold cost is relatively high, the advantage is that it can accurately ensure the thickness and size of composite materials, and has two components with smooth surface. The components commonly used in molding process are flight control parts, helicopter rotor, sports equipment and medical bed board. In the molding process, by giving a certain amount of interference to the foam core, the amount of interference in the mold closing process provides the counter pressure for the curing of the panel.
The compression creep property of PMI foam is the premise and guarantee of changing the interference volume into reverse pressure. By setting the suitable interference volume, according to the resin content of the ply, curing system, the thickness of the panel, the pressure of the back pressure is adjusted to meet the requirements of curing pressure.
Autoclave process: characterized by one side of hard mold, one side of soft mold. The cured composite laminates were pressurized by vacuumizing and pressurizing in autoclave. If the co curing process is adopted, that is, the curing of the CFRP panel and the bonding between the core material of the sandwich structure and the panel can be completed at one time. The gap of PMI foam is smaller than that of honeycomb, which can provide enough support for the curing of panels, and will not appear telegraphic effect like honeycomb structure panels.
RTM resin injection molding process: liquid resin injection is a relatively new and optimized manufacturing process. With the help of RTM technology, high-performance sandwich structure components are produced. At present, in order to simplify the production process, reduce the manufacturing cost, and save the price of raw materials, the cloth with relatively low price and good overlay performance can be selected to realize mass production, and the components can be used with high quality Amount of prepreg effect. If the voids of honeycomb are sealed to prevent the injection resin with low viscosity from flowing into the voids of honeycomb, honeycomb can also be selected as sandwich material in RTM manufacturing process.