In the production of rubber molded products, the difference between the process and the equipment used can be mainly divided into two categories; compression molding and injection molding.
Molding method
It is a process of directly adding a rubber compound or a preformed semi-finished product into a mold cavity, and then pressing it on the machine while heating and vulcanizing to obtain a product part. The production process is as follows: rubber → shear weighing or other preforming → loading into the mold cavity → pressurization, vulcanization → mold picking → repairing flash edge → finished product quality inspection. The molding method is widely used because the molding die structure and the equipment used are simple and versatile.
Injection molding method
a method in which a rubber material is directly injected into a mold cavity through a rubber injection machine to be sulfurized, thereby obtaining a product part. The production process is as follows: preheating and plasticizing of the rubber material→injection into the mold→vulcanization→moulding and picking up the parts→removing the flashing edge→quality inspection of the finished product. Injection molding requires first expensive injection equipment. In addition, the injection vulcanization process has not been widely adopted depending on various factors such as part type, quantity of production, mold manufacturing cost, and equipment limitations. However, with the rapid development of industry and agriculture, the rubber products produced by the injection vulcanization process will replace some of the molded products, because the rubber products produced by the injection vulcanization process are stable and reliable in quality and high in production efficiency.