LSR Overmolding on PC Manufacture

Liquid Silicone Rubber (LSR) over-molding on Polycarbonate (PC) is a widely used manufacturing technique that combines the durability of PC with the flexibility and sealing properties of LSR. This process is extensively used in consumer electronics, medical devices, and automotive applications to create high-performance, durable, and aesthetically appealing products.

What is LSR Overmolding?

LSR over molding is an advanced injection molding technique where LSR is directly molded over a rigid plastic substrate, such as PC, to create a single, integrated component. This process enhances the final product’s mechanical strength, grip, and resistance to environmental factors.

Why Use PC and LSR Together?

Polycarbonate (PC) is a lightweight yet strong thermoplastic known for its high impact resistance and transparency. When combined with LSR, the final product benefits from:

• High durability – PC provides rigidity, while LSR adds shock absorption.
• Enhanced sealing – LSR ensures waterproof and dustproof capabilities.
• Improved aesthetics and ergonomics – LSR adds a soft-touch feel and better grip.
• Chemical and heat resistance – The combination withstands harsh environments.

LSR Overmolding Process on PC

1. Surface Preparation

   • The PC substrate is cleaned and treated (e.g., plasma or corona treatment) to improve adhesion.
   • If necessary, a primer is applied to enhance bonding between PC and LSR.

2. Insert Molding

   • The pre-formed PC part is placed into the injection mold.

3. LSR Injection Molding

   • Liquid Silicone Rubber is injected over the PC part in a controlled process.
   • The LSR cures rapidly due to platinum-catalyzed vulcanization.

4. Cooling and Ejection

   • The molded part cools and is ejected from the mold with minimal post-processing required.

Applications of LSR Overmolding on PC

1. Smartphone Components

   • Waterproof gaskets, soft-touch buttons, and shock-absorbing edges.

2. Medical Devices

   • Non-slip grips for surgical instruments, wearables, and drug delivery systems.

3. Automotive Parts

   • High-performance seals, key fobs, and control buttons.

4. Consumer Electronics

   • Protective casings, wearables, and charging accessories.

Advantages of LSR Overmolding on PC

Enhanced Durability – The combination withstands impact, heat, and chemicals.
Seamless Integration – This creates a single component with improved structural integrity.
Soft-Touch Feel – Ideal for user-friendly, ergonomic designs.
Waterproofing and Sealing – Essential for electronics and medical applications.
Lightweight Yet Strong – PC keeps the structure rigid while LSR adds flexibility.