A Professional Guide to Using LSR Moulding

LSR moulding (Liquid Silicone Rubber moulding) is a highly specialized manufacturing process used to produce durable, flexible, and biocompatible silicone parts. It is widely adopted across medical, automotive, electronics, and consumer industries due to its precision and reliability. This guide outlines the key considerations, steps, and best practices for effective use of LSR moulding.

Understanding the LSR Moulding Process

LSR moulding involves injecting two-part liquid silicone rubber into a closed, heated mold under high pressure. The material cures rapidly inside the mold to form precise, elastomeric components. Unlike traditional rubber processing, LSR moulding is fully automated and ideal for producing complex geometries with high repeatability.

Key benefits of LSR moulding include:

• High thermal stability and chemical resistance.

  
  

• Excellent biocompatibility for medical and food-grade parts.

  
  

• Minimal waste and consistent cycle times.

  
  

• Suitability for micro parts and complex designs.

  
  

Design Guidelines for LSR Moulding

To achieve optimal results with LSR moulding, designers should follow specific guidelines:

• Uniform wall thickness: Avoid thick sections that slow down curing and cause warping.

  
  

• Proper venting: Ensure precise vent placement to prevent air entrapment.

  
  

• Undercuts and parting lines: Minimize complex features unless necessary; use lifters or collapsible cores if undercuts are required.

  
  

• Draft angles: Include slight draft angles (usually 0.5°–1°) for easier demolding.

  
  

These design principles ensure the integrity, performance, and longevity of LSR-moulded parts.

Material Selection and Application Considerations

Choosing the right silicone grade is critical for successful LSR moulding. Manufacturers must consider:

Material properties such as durometer (hardness), colorability, and cure rate should also match the part's end-use conditions.

Quality Control and Maintenance Best Practices

Maintaining high product quality is essential in LSR moulding. Best practices include:

• Consistent process monitoring: Use automated systems to control injection pressure, temperature, and timing.

  
  

• Tool maintenance: Regularly clean and inspect molds to avoid contamination and wear.

  
  

• Post-mould curing (if needed): Some medical and high-purity parts require secondary heat treatment for full property development.

  
  

• Testing and validation: Conduct dimensional inspections, tensile testing, and biocompatibility analysis based on the application.

  
  

A robust quality control system ensures compliance with industry standards and customer specifications.