RIM refers to the process of ordinary non-reinforcing materials; RRIM mainly refers to the material or process prepared by reacting with another component after relatively short fibers or other reinforcing materials are mixed with the reaction material; SRIM refers to the continuous long fiber pre-prepared In the cavity, and then inject the reaction material liquid into the cavity and pass through the fiber mat to react the material or process. This process has been vigorously developed and promoted in automobile giants such as Daimler, Ford and General Motors; MC-RIM It refers to multi-component reaction injection molding, also known as “multi-stage injection RIM”, that is, the material of the skin and the center part is injected into the cavity successively; GRIM refers to thin-walled and hollow parts, this process can save about 40% RIRM is called Rotary Reaction Injection Molding, which is characterized by no restriction on the viscosity of the material, and there are two injection methods: one is the rotary injection mixing method with the small hole as the injection port, and the other is the gap as the injection port. Rotary plane jet mixing method at the injection port.