HC Plastics Network News: Due to the strong adhesion of polyurethane to metal and other materials, release agents are generally required when producing polyurethane molded products, and the RIM process is no exception. There are two types of release agents in the RIM process: external release agents and internal release agents.
Currently, the commonly used external release agents are paraffin wax and silicone release agents. Can be formulated into a solution for easy and economical coating of molds. A 2% to 10% hydrocarbon solution of polyethylene wax can also be used as an external release agent for RIM polyurethane materials such as car bumpers. If the parts have painting requirements. Silicone release agents need to be used with caution, otherwise the entire coating may not be possible.
(Jiangxi New Materials Co., Ltd.)
In order to meet the requirements for improving production efficiency, internal release agents were developed as important additives for RIM polyurethane (urea). The internal release agent is an additive added to the formula to play a release role. During the polyurethane molding process, it can partially migrate to the surface of the product and play an isolation role.
The initially developed internal release agent was a polysiloxane compound containing active organic groups, which has been widely used around the world. Polymer compounds with long chain segments of fatty acid polyester in the middle and end groups of hydroxyl polyether and amine-terminated polyether, and adducts of higher fatty alcohols or amines and ethylene oxide (nonionic surfactants) are also commonly used. Internal release agent. Zinc stearate is a non-reactive internal mold release agent. 
Editor in charge: Li Dongpeng
