Liquid Silicone Rubber

Liquid silicone rubber moulding is a thermoset process that mixes a two-component compound together, which is then heat cured in the mould with a platinum catalyst to produce a final LSR part.

LSR design guidelines will help you understand capabilities and limitations. 

Why Choose Liquid Silicon Rubber Moulding for your project?

Liquid Silicon Rubber has excellent thermal, electrical, and chemical resistance properties, although it can be attacked by certain solvents such as gasoline or mineral spirits, which is why it can be used in high-temperature automotive applications but not for fuel lines. And it has low compression set—low permanent deformation when a force is applied and removed—making it ideal for elastomers. This allows for faster and most cost-effective tooling when compared to traditional steel moulds. We offer a number of additional moulding and tooling services to support your project.

How Does Liquid Silicon Rubber Moulding Work?

Due to the flexible nature of LSR, parts are manually removed from the mould, and thus, ejector pins are not built into the mould design. Like a standard aluminium tool, an LSR moulding tool is fabricated using CNC machining to create a high-temperature tool built to withstand the LSR moulding process. After milling, the tool is polished by hand to customer specifications, which allows six standard surface finish options.

The finished tool is loaded into an advanced LSR-specific injection moulding press that is precision geared for accurate control of shot size to produce the most consistent LSR parts.

Since LSR is a thermosetting polymer, its moulded state is permanent—once it is set, it can’t be melted again like a thermoplastic. When the run is complete, parts (or the initial sample run) are boxed and shipped shortly thereafter.

For more information on liquid silicone rubber (LSR) moulding process to help you improve your LSR moulded parts, read our LSR white paper.

Injection moulding icon

25 to 10,000+

Shipped in 15 days or less


Best for:
  • on-demand parts
  • low-volume production
  • bridge tooling
  • pilot runs
  • functional prototyping

LSR Materials

We stock a range of LSR materials that are suitable for various part applications and industries. Choose from standard silicones in multiple durometers along with optical-, medical-, and fuel-resistant grades.



Design Guidelines

Our basic guidelines for LSR moulding include important design considerations to help improve part manufacturability, enhance cosmetic appearance, and reduce overall production time.



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