Product Spotlight

Apple Rubber’s Quick Guide to Liquid Silicone Rubber

Liquid Silicone Rubber (LSR) is a type of high-purity, two-component silicone which is typically processed through liquid injection molding. Its formulation makes it a strong choice in the production of technical parts, especially when strength, durability, and quality are vital.

Chemical Structure

Liquid Silicone Rubber is a two-component system, but what does this mean? LSR, like all two-component systems in chemistry, is made up of two chemically independent elements. 

In LSR’s case, the components are polysiloxane chains and specially treated silica. The first component contains a platinum catalyst while the second component contains methylhydrogen siloxane, which acts as a cross-linker and alcohol inhibitor. 

Due to the thermosetting nature of the material, liquid silicone rubber injection molding requires special treatment, such as intensive distributive mixing, while maintaining the material at a low temperature before it is pushed into the heated cavity and vulcanized.


Depending on the application or its industrial use, LSR offers several advantages. First, it is highly biocompatible, which means it can be used for parts that come into contact with humans. This makes it a great choice for applications such as organ parts or prostheses. Second, it is very durable, ensuring long-term stability and chemical resistance. Third, it is also compatible with a wide spectrum of temperatures ranging from -60°C to +250°C. In spite of wide temperature ranges, the material is able to maintain its high-performance mechanical properties at all times. Fourth, its electrical properties make it ideal for insulation and precise conductivity protection. Finally, it is transparent and can be pigmented to any color, including human skin tones.

LSR are also considered as the material of choice for industries such as Automotive or Medical devices for which small and complex elastomeric parts need to be produced at high speed and optimum productivity. In such cases, Liquid Injection Molding of LSRs becomes one of the most efficient processes for fabricators.

Looking for more on the material that does it all?

Check out Apple Rubber’s silicone offerings here.