Liquid silicone rubber is a kind of flexible thermosetting material with non-toxic, heat resistance and high recovery. Its rheological behavior is mainly characterized by low viscosity, rapid curing, shear thinning and high coefficient of thermal expansion.

LSR is a double liquid rapid vulcanization material with platinum as catalyst. It can be produced by injection molding, mass, rapid vulcanization and repetitive machinery. Its products show good thermal stability, cold resistance, excellent electrical insulation performance, and will not produce toxic substances during combustion.

Therefore, it has become an irreplaceable material in the production and design of health products, automobiles, baby products, medical products, diving products, kitchen appliances and seals.

summary

Injection molded liquid silicone rubber (LSR) is a kind of addition molded liquid silicone rubber. It uses its own characteristics of low viscosity (certain fluidity and amorphous before vulcanization) and easy to feed with metering mixing equipment. It uses special injection molding equipment to accurately and automatically feed, mix and inject the two components, and then vulcanize rapidly to form products. Injection molding process has gradually replaced the traditional molding process, which has many advantages: using liquid injection molding process for vulcanization molding, accurate measurement and less material waste; Low vulcanization temperature, short molding cycle and low production cost; High precision products, can process complex shape products; There is no by-product in the vulcanization process, and there is no need for two-stage vulcanization; The products have excellent aging resistance, weather resistance, non toxicity, high transparency, high mechanical strength and good elasticity [1-2]. Therefore, liquid injection molding silicone rubber has become the preferred material in the fields of daily rubber products such as baby products, daily products, power insulation material processing, kitchen accessories manufacturing and so on. It is one of the fastest developing products in silicone rubber.

Liquid silicone rubber injection molding technology (LIM) is a new and efficient silicone rubber molding method developed in the late 1970s. It is a new silicone rubber molding technology formed by combining liquid silicone rubber with excellent performance with equipment that can accurately and stably complete injection molding. It only needs two components (including color matching and other auxiliary components) It is loaded into the equipment and completed automatically from feeding, metering, mixing to forming. This processing technology can simplify the process, shorten the processing time, save materials and improve efficiency. And there is basically no waste edge in the production process, which is conducive to environmental protection.

With the wide application of liquid silicone rubber and the improvement of product requirements, more and more people have recognized and adopted this technology to produce silicone rubber products, ushering in a new era of high-efficiency, high-quality and low-cost production in silicone rubber processing industry. With the continuous expansion of the application scope of injection molding technology, it is expected to have greater competitiveness in replacing traditional elastomer products.

Introduction to injection molding process

The injection molding process of liquid silicone rubber is as follows: two liquid silicone rubber raw materials a and B are accurately measured by the metering device and then transported to the mixing device; The two components are fully mixed in the mixer and then transported to the injection molding machine; Injection or injection into the preheated multiple molds through the molding machine and evenly distributed into each mold cavity; In the hot mold cavity, the silicone rubber material is heated and vulcanized rapidly to form the product; After vulcanization molding, the mold is opened automatically; Then close the mold and enter the next forming cycle. The whole forming cycle lasts from tens of seconds to a few minutes, and the forming cycle is different according to the size of the product.