The manufacturing method of epoxy resin plastics
The adhesiveness of epoxy resin is very good, so it is necessary to add mold release agent to make the products easy to remove film. Commonly used release agents are zinc stearate, calcium stearate, special fatty acids, esters and waxes. There are three manufacturing methods of epoxy resin plastics. I’ll introduce you to you today.
(1) the dry method. The epoxy resin, curing agent and other materials will be comminuted and fully mixed, so the resins and curing agents used must be solid. In order to mix more evenly, it is necessary to prepare for forming or rolling. The plastic obtained by this method is more suitable for transfer molding than compression molding.
(2) the semi hardening method. The epoxy resin of the liquid is reheated with the aromatic amine curing agent, and the intermediate cooling makes the reaction stop, making it in the soluble solid state (equivalent to the B order state). This kind of B order resin can be stored for a week at room temperature, and some even can be stored for more than one year. The disadvantage of using this B – order resin to remake plastic is that the reaction temperature, the degree of reaction and the cooling method are difficult to master, so the quality of the plastic is difficult to control.
(3) melting method. This method starts with the dry method, first comminution of all kinds of materials, and then mix it up in the hot roller or kneading machine as far as possible without reaction. This method is different from the dry type. The liquid can be used as the curing agent, and the mixing is more uniform. In addition, the melting point and the fluidity of the plastic can be adjusted according to the temperature and time of heat mixing. The disadvantage is that compared with dry process, the storage period of pressed powder is shorter.