“Liquid silica gel” is a non-toxic, heat-resistant, highly resilient, flexible thermoset material. The industry is commonly known as LSR (Liquid Silicone Rubber).

The product exhibits good thermal stability, cold resistance, excellent electrical insulation properties, and does not produce toxic substances when burned.

LSR injection molding process:

LSR injection molding is divided into A component and B component, and the mixer thoroughly mixes the A component and the B component in a precise 1:1 ratio. Since some of the products are colored, the mixer is equipped with a color pump set and a color metering section. The A+B components, additives, colors, etc. are thoroughly mixed and then enter the plasticizing system.

Key process requirements for LSR injection molding:

The rheological behavior of LSR is mainly characterized by low viscosity, rapid solidification, shear thinning and high coefficient of thermal expansion. Therefore, it is necessary to control and control the process of the molding production process. Especially in the relevant aspects of feeding and injection molding.

Feeding - one-way pump system:

Synchronous single-stage pumps with check valves also need to be equipped with corresponding metering cylinder systems to effectively control the accuracy of the feed.

Injection - Mold Design:

Since the LSR has a high expansion coefficient, it expands when heated, and has a slight shrinkage during cooling. Therefore, the parts cannot maintain precise side margins in the mold, so the cold runner mold design should be used. In order to avoid turbulence and spraying, a needle-like or wing-shaped small injection port is used. Replace the cylindrical guide pin with a T-shaped guide pin to increase the positioning accuracy. Set the insulation layer/board to facilitate the demolding of the LSR.

Injection molding - injection molded parts:

Due to the low viscosity of the LSR, the backflow and leakage of the material are taken into consideration during processing, so the sealing of the injection screw is very important. When the shot is finished, the nozzle will be closed immediately and a needle nozzle must be used.

Market prospects for LSR injection molding technology:

“Injection molding technology of liquid silicone material” is a new high-efficiency silicone rubber molding method developed in the late 1970s. After years of research and development, the market has increasingly used this technology to produce silicone rubber products. A new era of high efficiency, high quality and low cost production in the silicone rubber processing industry.

Compared with the traditional thermal vulcanization molding process, the production of rubber products by this project technology process has the advantages of time saving and energy saving, no post-treatment process, high product yield and low comprehensive cost (saving about 40%).