Solid Silicone Rubber: Grades, Properties & Applications

Solid silicone rubber is one of the most versatile and widely used elastomer materials in modern manufacturing.
From automotive sealing systems to medical devices, from high-temperature equipment to consumer electronics, solid silicone offers a unique combination of thermal stability, flexibility, durability, and safety.

In this article, we will introduce the most common grades of solid silicone rubber, explain their key properties, and provide guidance on choosing the right grade for your application.

1. What Is Solid Silicone Rubber?

Solid silicone rubber—also known as HTV silicone rubber (High Temperature Vulcanized)—is a type of silicone material that is cured under heat and pressure.
It is supplied in blocks, slabs, or milled sheets, and processed through methods such as:

• Compression molding

• Extrusion

• Die cutting

• Calendering

Unlike liquid silicone rubber (LSR), solid silicone has a higher viscosity and is ideal for producing gaskets, sheets, pads, seals, and mechanical components with stable physical properties.

2. Common Grades of Solid Silicone Rubber

Solid silicone rubber comes in several grades based on purity, curing method, and performance.

(1) General-Purpose Silicone Rubber

• Widely used in industrial sealing

• Temperature resistance: -60°C to +200°C

• Good flexibility and mechanical strength

• Cost-effective for mass production

(2) High-Temperature Silicone Rubber

• Specially formulated to reach +250°C or even +300°C short-term

• Ideal for heaters, ovens, engine components

• Excellent thermal stability and low compression set

(3) Food-Grade / FDA Silicone Rubber

• Manufactured with platinum curing (addition cure)

• Odorless, non-toxic, non-yellowing

• Complies with FDA 21 CFR 177.2600, LFGB, RoHS, REACH

• Common in kitchenware, food machinery, water systems

(4) Flame-Retardant Silicone Rubber

• UL94 V0 or V1 compliant

• Suitable for electronics, EV batteries, transportation

• Creates protective ash layer during combustion

(5) Electrically Conductive Silicone Rubber

• Filled with carbon or silver materials

• Used for EMI shielding and grounding components

(6) High-Strength / Reinforced Silicone Rubber

• Improved tear resistance and elasticity

• Ideal for dynamic sealing and mechanical movement parts

3. Key Properties of Solid Silicone Rubber

✔ Excellent Temperature Resistance

One of the major reasons industries use silicone:

• Works reliably from −60°C to +200°C

• Short-term resistance up to +250–300°C depending on grade

Suitable for harsh environments where traditional elastomers fail.

✔ Outstanding Weather & Aging Resistance

Silicone rubber is naturally resistant to:

• UV

• Ozone

• Oxygen

• Humidity

• Outdoor aging

This ensures long service life.

✔ High Flexibility & Elasticity

Even under extreme temperatures, silicone remains soft and elastic—ideal for sealing and vibration isolation.

✔ Safe & Non-toxic Options

Platinum-cured grades meet food, medical, and drinking-water requirements.

✔ Electrical Insulation

Solid silicone rubber provides stable dielectric properties for electronic applications.

✔ Customizable Hardness & Colors

• Hardness: 10–90 Shore A

• Colors: red, black, white, grey, blue, transparent, or fully customized

4. Typical Applications of Solid Silicone Rubber

Industrial & Mechanical

• Gaskets & seals

• Insulation pads

• Anti-vibration components

• High-temperature machinery parts

Automotive & EV Industry

• Engine gaskets

• Battery module seals

• Heat shields

• Connective profiles

Electronics & Electrical Equipment

• Insulation sheets

• Flame-retardant components

• Keypads and switches

• Potting & sealing materials

Medical & Food Industries

• FDA-grade seals

• Tubing components

• Kitchen tools

• Drinking water systems

Aerospace & Rail Transit

• Fire-protection materials

• Thermal insulation parts

• Durable sealing systems

5. Why Choose Solid Silicone Rubber from Laimeisi?

With advanced manufacturing and ISO-certified processes, Laimeisi provides:

• Stable quality through high-precision mixing and vulcanization

• Wide hardness range from 10A to 90A

• High-temperature + flame-retardant formulations

• FDA / LFGB food-grade options

• Consistent sheet thickness from 0.5 mm to 50 mm

• Custom colors, widths, and mechanical properties

• Reliable global supply chain and short lead time

Our solid silicone rubber materials are trusted by customers in automotive, electronics, new energy, medical, and industrial sectors worldwide.

Conclusion

Solid silicone rubber is a high-performance elastomer with outstanding heat resistance, chemical stability, and long-term durability.
Whether you need gasket materials, insulation sheets, food-grade components, or flame-retardant parts, solid silicone offers unmatched stability across a wide range of applications.

If you need help choosing the right silicone rubber grade or thickness, our technical experts are ready to assist you.