What Is Liquid Silicone Rubber Used For? A Complete Guide for Modern Manufacturing

Liquid Silicone Rubber (LSR) has become one of the most important materials in today’s manufacturing industry. Its ability to combine precision molding, long-term durability, and outstanding safety performance makes it ideal for medical devices, food-contact products, electronics, and automotive parts.

This article explains what LSR is, how it works, its unique benefits, and the industries that rely on it—helping engineers, brands, and product developers understand why LSR continues to rise in global demand.

1. What Is Liquid Silicone Rubber (LSR)?

Liquid Silicone Rubber is a two-component, platinum-cured silicone system designed for high-precision injection molding.
It consists of:

• Part A: Contains a platinum catalyst

• Part B: Contains a crosslinker and additives

Once mixed, these two components undergo an addition-cure reaction that forms a stable, elastic structure. Unlike traditional solid silicone requiring compression molding, LSR is:

• Low-viscosity

• Automatically dosed and mixed

• Fast-curing

• Suitable for fully automated production

This makes LSR ideal for producing high-volume, complex, and medical-grade silicone components.

2. Key Characteristics of Liquid Silicone Rubber

LSR is favored because it delivers performance levels unattainable with traditional rubbers. Below are its most notable characteristics.

Outstanding Temperature Resistance

• Performs reliably from –60°C to +250°C

• Maintains elasticity under extreme heat and cold

• Does not melt, degrade, or release harmful substances

Chemical and Environmental Stability

• Resistant to ozone, UV radiation, moisture, and oxidation

• Maintains performance even after long-term outdoor exposure

Biocompatibility and Safety

• Hypoallergenic and odorless

• Suitable for skin-contact and medical applications

• Certified for food-grade use (FDA, LFGB, BfR etc.)

High Mechanical Strength

• Strong tear resistance

• High tensile strength

• Excellent flexibility and rebound performance

Electrical Insulation

• Stable dielectric properties across a wide temperature range

• Ideal for electrical sealing and insulation parts

Dimensional Precision

LSR exhibits minimal shrinkage during curing, enabling high-precision molding for micro-sized and tight-tolerance components.

3. Advantages of LSR Injection Molding

The rapid growth of LSR is closely tied to LSR injection molding, a process that brings major engineering and production benefits.

High Efficiency for Mass Production

• Automated mixing and dosing

• Fast curing cycles

• Suitable for 24/7 continuous manufacturing

Ability to Mold Complex Geometries

• Thin-wall parts

• Micro-molded components

• Intricate sealing structures

Low Flash and High Consistency

• Advantageous for medical and infant products

• Reduces post-processing and waste

Supports Overmolding and Two-Shot Molding

LSR bonds permanently with many materials, including:

• Engineering plastics

• Stainless steel

• Aluminum

• Electronics or sensitive components

This allows manufacturers to create ergonomic grips, soft-touch areas, durable seals, and multifunctional components in a single process.

4. What Is Liquid Silicone Rubber Used For?

Due to its versatility, LSR is applied across many high-performance industries. Below are the most common sectors.

1) Medical and Healthcare

LSR is widely used in medical-grade applications due to its biocompatibility and sterilization resistance.

Common medical uses include:

• Catheters

• Respiratory masks and valves

• Sealing caps

• Infant care products

• Wearable health devices

Its ability to withstand autoclave sterilization makes LSR ideal for clinical environments.

2) Baby and Food-Contact Products

Food- and medical-grade LSR offers unmatched safety for baby and kitchen products.

Typical applications:

• Baby bottle nipples

• Teethers and feeding accessories

• Ice molds and baking molds

• Silicone lids and gaskets

• Freeze trays and kitchen tools

LSR’s resistance to heat, cold, and chemicals ensures long-lasting, hygienic performance.

3) Electronics and Consumer Devices

LSR is widely used in electronic devices that require soft-touch surfaces or waterproof protection.

Examples:

• Smartphone protective cases

• Keypads and buttons

• Smartwatch straps

• Earbud tips

• Connector seals

Its insulation, sweat resistance, and durability make it ideal for wearable electronics.

4) Automotive and Industrial Applications

LSR withstands the extreme conditions found in automotive and industrial environments.

Typical uses include:

• Engine compartment seals

• Electrical connector gaskets

• Vibration dampers

• Headlamp seals

• High-temperature O-rings

The material maintains stability in heat, oil, ozone, and outdoor conditions.

5) Household and Daily Use Products

LSR is also popular for daily consumer products:

• Kitchen utensils

• Heat-resistant handles

• Reusable storage containers

• Sealing rings

• Home appliances

Its long service life reduces waste and enhances sustainability.

5. Why LSR Demand Continues to Grow

Several global trends contribute to the increasing demand for liquid silicone rubber:

• Growth of wearable medical devices

• Rising consumer preference for food-safe materials

• Expansion of automotive electronics

• Increasing need for durable waterproof components

• Replacement of plastic with safer alternatives

With the ability to meet both functional and regulatory requirements, LSR is becoming a top choice for modern product development.

Conclusion

Liquid Silicone Rubber stands out as one of the most versatile and high-performance materials available today. Its ability to endure extreme temperatures, maintain biocompatibility, deliver precise molding, and bond with other materials makes it ideal for a wide range of industries—from medical devices and baby products to consumer electronics and automotive components.

As manufacturing technology advances, LSR will continue to play a key role in creating safer, more durable, and more innovative silicone products.