Why is silicone rubber ideal for molding applications?

Manufacturers in various industries, including automotive, healthcare, general industrial, infant care, consumer goods and electronics require easy-to-mold (and demold) low or high-viscosity rubber silicones to produce parts efficiently and cost-effectively.

Silicone rubber is the material of choice in manufacturing rubber parts. The silicone backbone is composed of repeating Si-O chains which are extremely flexible in nature giving this chemical structure unique properties such as a broad operating temperature range, weatherability, being hydrophobic, bio-inertness, electrical insulation and an overall long-life span.  Silicone rubber used in molding applications is available in either high consistency rubber or liquid silicone rubber.  Each raw material form requires specific molding processes.

Liquid silicone rubber (LSR) 

Liquid injection molding is the process used with LSR to fix the material from an uncured state into a cured part.  

  • The highly viscous LSR is extracted from drums or pails using a dosing unit and injected into a closed mold in the press.  
  • The mold is then heated, and the heat combined with pressure applied to the LSR results in the rubber becoming a solid part.  

The ability to automate the filling process as well as short cure times, allows a rapid part production cycle and limited labor costs making injection molding with LSR a cost-effective process for high volume production for a wide range of applications. Elkem Silicones' LSR Select™  is our patented, advanced system of materials designed to enhance the operation, control, flexibility, and productivity of liquid silicone rubber injection molding processes. 

High Consistency Rubber (HCR)

Transfer molding or compression molding is the ideal process for high consistency rubbers (HCRs), especially for large parts such as electrical insulators.  

  • Transfer molding incorporates a container above the mold where re rubber sits and gets pushed into the mold using a piston-powered gate system
  • Compression molding uses high pressure to squeeze a pre-formed piece of rubber into a mold between two or more plates, depending on the part or product configuration
Elkem Silicones works with you to define which compounds are the most cost effective and best suited to your processing conditions, to achieve the performance levels you require. Our technical team has expertise on both materials and can advise you in your choice and all along your development.