Injection molding liquid silicone rubber (LSR) is a kind of addition molding liquid silicone rubber. It takes advantage of its low viscosity (it has a certain fluidity and amorphousness before vulcanization) and is convenient for feeding by metering and mixing equipment. The special injection molding equipment automatically feeds, mixes, and molds the two components, and then quickly vulcanizes them to form products. The injection molding process has gradually replaced the traditional molding process, and has many advantages: the liquid injection molding process is used for vulcanization molding, accurate measurement, and less material waste; low vulcanization temperature, short cycle time of molded products, and reduced production costs; high product precision, complex processing Shaped products; there are no by-products in the vulcanization process, and no secondary vulcanization is required; 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, electrical insulation material processing, and cabinet accessories manufacturing, and is one of the fastest growing 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 combines liquid silicone rubber with excellent performance and equipment that can complete injection molding precisely and stably The new type of silicone rubber molding and 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.

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 the silicone rubber processing industry. . With the continuous expansion of the application range of injection molding technology, it is expected to have greater competitiveness in replacing traditional elastomer products.

The liquid silicone rubber injection molding process is as follows: the two kinds of liquid silicone rubber raw materials A and B are accurately metered by the metering device and then delivered to the mixing device; the two components are fully mixed in the mixer and then delivered to the injection molding machine; The molding machine injects or sprays into the preheated multiple molds and distributes them evenly to each mold cavity; in the hot mold cavity, the silicone rubber material is heated and rapidly vulcanized to form the product; after the vulcanization molding, the mold is automatically opened and ejected; then the mold is closed and enter 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 directly measures the two components of the liquid silicone rubber into the system from the packaging barrel through the hydraulic pressure plate; the second unit is the mixing unit , the two components entering the system are fully mixed through the static mixer, and no air bubbles are brought into the system; the third unit is the injection molding unit, and the mixed silicone rubber material is quantitatively injected into the mold through the injection unit, and uniformly Distributed to each cavity, then hot vulcanized. The whole process is fully automated, and manual control can be achieved after setting the parameters to improve production efficiency.