If you’re new to lsr injection, you’re stepping into a world of precision, durability, and design flexibility. Liquid Silicone Rubber (LSR) is widely used across industries for its excellent thermal stability, chemical resistance, and ability to produce high-quality parts with complex geometries. At Fox Mold, we’ve put together expert tips to help you confidently begin your journey with LSR injection molding.

What is LSR Injection?

LSR injection molding is a process that involves injecting liquid silicone rubber into a mold cavity to create intricate, durable parts. Unlike traditional thermoplastics, LSR cures into a flexible, rubber-like material, making it ideal for medical devices, automotive components, electronics, and consumer products.

Why Choose LSR Injection?

There are several compelling reasons to choose LSR injection over other molding techniques:

Heat resistance: Withstands high temperatures, making it perfect for automotive and electrical applications.
Chemical stability: Great for harsh environments.
Biocompatibility: Safe for use in medical and food-grade products.
Precision molding: Allows for intricate part designs with tight tolerances.

At Fox Mold, we often recommend LSR injection when clients need long-lasting, high-performance parts produced in large volumes.

Choosing the Right LSR Injection Machine

The machine you select for LSR injection plays a critical role in achieving consistent results. You’ll want to look for features like:

Closed-loop controls for precise injection.
Cold-runner systems to reduce waste.
Vacuum systems to prevent air entrapment.

A high-quality LSR injection machine minimizes cycle times while maximizing part quality.

Material Selection: Choosing the Right LSR

Not all LSR materials are created equal. Depending on your application, you’ll want to choose a silicone compound with the appropriate:

Hardness (durometer)
Tear and tensile strength
Transparency or pigmentation
FDA or medical-grade certifications

We help clients navigate these decisions to find the best-fit LSR for their specific LSR injection application.

Designing for LSR Injection

Designing for LSR injection is different from designing for traditional plastics. Here are some essential tips:

Uniform wall thickness to reduce shrinkage.
Undercuts and complex geometries are easier to mold with LSR.
Generous draft angles help with part ejection.
Proper venting in the mold to avoid defects.

Our design team at Fox Mold uses simulation tools to optimize part and mold designs before any tooling is built, saving you time and money in the long run.

Tooling Considerations for LSR Injection

Tooling is arguably the most important aspect of LSR injection molding. High-quality molds ensure efficient cycles and minimal defects. Important considerations include:

Steel selection: Hardened steel is preferred for longevity.
Surface finish: Impacts part release and aesthetics.
Temperature control: Mold temperature must be tightly regulated.

When you work with us at Fox Mold, you’ll get molds that are specifically tailored to the LSR process.

Quality Control and Testing

To ensure your LSR injection parts meet the highest standards, you should implement:

Visual inspections
Dimensional analysis
Tensile and tear testing
Compression set tests

LSR parts are often used in critical applications, so thorough testing is non-negotiable.

Common Mistakes to Avoid in LSR Injection

Even seasoned manufacturers make mistakes with LSR injection. Here are some to avoid:

Improper mixing of LSR components
Overlooking mold venting
Ignoring cure times
Using the wrong durometer for the application

Partnering with an experienced team like Fox Mold can help you navigate these challenges seamlessly.

Final Thoughts

Getting started with LSR injection molding can seem overwhelming, but with the right guidance, tools, and materials, it’s a highly rewarding process. From precision design to high-volume production, LSR injection offers unmatched versatility and performance.