Liquid silicone rubber injection molding (LIM) is a new and efficient silicone rubber molding method developed in the late 1970s. It combines liquid silicone rubber with excellent performance and equipment that can complete injection molding precisely and stably. The new type of silicone rubber molding processing technology formed only needs to load two components (which can also include auxiliary components such as color matching) into the equipment, and it is fully automatic from feeding, metering, mixing to molding. This processing technology can achieve the purpose of simplifying the process, shortening the processing time, saving materials and improving efficiency. And basically no waste edges are produced in the production process, which is beneficial to environmental protection.

The two liquid silicone rubber raw materials A and B are accurately metered by the metering device and then sent to the mixing device → the two components are fully mixed in the mixer and then sent to the injection molding machine → injected or injected by the molding machine into the pre-prepared The hot multi-mold is evenly distributed into each mold cavity → the silicone rubber material is heated in the hot mold cavity and rapidly vulcanized to form the product → after vulcanization molding, the mold is automatically opened and the mold is released → then the mold is closed and enters the next molding cycle. The entire molding cycle takes tens of seconds to several minutes, and the molding cycle varies according to the size of the product.


The entire injection molding system is divided into the following parts:

The first unit is the metering and feeding unit, which accurately meter the two components of the liquid silicone rubber directly from the packaging barrel into the system through the hydraulic pressure plate;

The second unit is a mixing unit, which fully mixes the two components entering the system through a static mixer, and does not bring air bubbles into the system;

The third unit is the injection molding unit. The mixed silicone rubber material is quantitatively injected into the mold through the injection unit, and evenly distributed to each mold cavity, and then thermally vulcanized. The whole process is fully automated, and manual control can be achieved after setting the parameters to improve production efficiency.

This plasticizing screw has the functions of homogenization and mixing at the same time. The mixture is injected into the hot mold through the screw. At the mold temperature of 170-200 °C, the silica gel undergoes a curing reaction. When using a cold runner system, it is important to note that the runner must be sufficiently cold. In order to avoid glue leakage, the needle valve is installed on the surface of the mold part. When the glue injection is completed, the needle valve immediately closes the nozzle.