What Is Silicone Rubber? A Guide to Types, Common Applications, and Custom Processing

Silicone rubber (elastomeric silicone) is no longer an unfamiliar material to most people. It is widely used in everyday life and can be found in products such as kitchen utensils, remote controls, automotive dashboards, and many other applications. However, there are still some people who feel unfamiliar with silicone rubber, and even regard it as the same as rubber. Because the two materials appear similar in appearance, silicone rubber is sometimes mistakenly believed to share the same limitations as traditional rubber, such as poor heat resistance and the potential to release harmful substances when exposed to high temperatures. , And such a misunderstanding makes many people miss out on excellent materials that are actually resistant to high temperatures, impact-resistant, eco-friendly and non-toxic. Below, we will introduce the common types of silicone rubber and traditional rubber.
 

Difference Between Silicone Rubber and Ordinary Rubber

Silicone Rubber (Elastomeric Silicone)

Silicone rubber, also known as elastomeric silicone, has good resistance to high and low-temperature, and the tolerance is generally between -40°c to 220°c. In addition, it is not toxic, so it is suitable for use in the biomedical field and the food industry. Its waterproof properties are also very suitable for the needs of seals. Another key advantage of elastomeric silicone itself is that it is an electrical insulator, so it can provide sealing functions like washers or gaskets and buffering functions like bumpers or spacers in electronic parts while ensuring product stability. Since silicone rubber is not tear-resistant and wear-resistant, it will not be used on objects subject to high-intensity impacts. The common elastomeric silicone classifications are as follows:
 

High Temperature-Vulcanizing silicone rubber (HTV/HCR)

High-temperature vulcanized silicone rubber (HTV) is a commonly heard solid silicone rubber. In Europe and the U.S. markets, it is also often referred to as High Consistency Rubber (HCR) or Heat-Cured Rubber. HTV performs well in heat and cold resistance as well as aging resistance. It can be processed into various products by hot press molding, extrusion molding, and other molding methods. Its applications can be seen in products ranging from industrial silicone rubber gaskets, hoses, O-rings, and molded components to everyday buttons.
〈Extended reading: Comprehensive Guide to Silicone Gaskets: Material Properties, Applications, and Design Essentials〉
〈Extended reading: High-Temperature Silicone: Characteristics, Applications, and Buying Guide〉
〈Extended reading: What is Solid Silicone HTV〉
 

Room-Temperature-Vulcanizing silicone rubber (RTV)

Room temperature vulcanized silicone rubber (RTV) is a type of silicone rubber. RTV is also subdivided into many types, such as dealcohol  type, deoxime type belonging to neutral silicone, and so on. Their common feature is that they all have good fluidity and can penetrate into irregular gaps. The non-conductive properties are also often used in the coatings of electronic parts to isolate the parts from air impurities, thereby improving the life of electronic equipment. However, it should be noted that different types of room-temperature vulcanized silicone rubber will also show different corrosiveness on certain substances, so it needs to be used in conjunction with appropriate materials.
 

Liquid Silicone Rubber (LSR)

The raw material of liquid silicone rubber (LSR) is liquid and has high transparency, so it is very suitable for use in optical equipment; due to its high fluidity, it can completely fill the entire mold, so the production method is mainly injection molding, and the whole process is sealed to ensure the cleanliness of the product. They are suitable for food utensils and human invasive medical equipment with high cleaning requirements, and can also produce complex and highly customized products. However, the cost of liquid silicone rubber is also the highest among the three due to its few raw materials and the high price of the injection machine.
〈Extended reading: Applications of Liquid Silicone Rubber Injection Molding in smart clothing〉
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Rubber

There are dozens of common types of rubber. According to the material, rubber can be divided into two categories: natural rubber and synthetic rubber. However, in order to facilitate the understanding of the general public, usually only the word rubber is used to cover different types of rubber. In fact, each rubber has different heat resistance, cold resistance, friction resistance, elasticity and strength, so there are quite different applications between different rubbers. Let us briefly introduce:
 

Natural rubber

Natural rubber is the earliest elastic material that was discovered and used. It has been developed for more than a hundred years, and the research and application of rubber has also been quite skilled. In recent years, with the continuous improvement of the development and technology of synthetic rubber, although the amount of use exceeds that of natural rubber, some synthetic rubbers are the products of further synthesis of natural rubber, so they still have an irreplaceable key position in the market. The biggest advantage of natural rubber is that it has high ductility and tear resistance, which makes it very suitable for high physical impact occasions, such as tires, rubber shoes, etc. Although natural rubber has low chemical resistance and is susceptible to acid corrosion and sunlight aging, adding antioxidants to it can improve its chemical resistance. With such flexibility and low production costs, natural rubber is a very popular rubber material.

Synthetic Rubber

Limited by the low output of natural rubber, low chemical resistance, and the increase in demand for rubber due to the birth of automobiles, the factory has the idea of producing synthetic rubber. When scientists knew that natural rubber was made of isoprene, they synthesized it with other chemicals on this basis, and eventually developed a variety of synthetic rubbers, which have developed dozens of rubbers today. Compared with natural rubber, the tear resistance and physical strength of synthetic rubber are generally inferior to natural rubber, so natural rubber still plays an indispensable role. Common types of synthetic rubber include styrene-butadiene rubber, which is cheap and wear-resistant, with excellent oil resistance, nitrile-butadiene rubber suitable for raw materials of seals, and fluorine rubber with the highest comprehensive performance.
 

Comparison of silicone rubber and rubber

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Application area of Elastomeric Silicone

Silicone rubber has stable physical properties and high environmental protection. Therefore, there are many successful cases of replacing rubber materials with silicone rubber in recent years, and the rise of emerging industries such as medical beauty and minimally invasive surgery has made silicone rubber increasingly unshakable.
 

Aerospace industry

The operating environment of equipment in the aerospace industry is often extreme climates. To maintain the required elasticity of parts at such temperatures, the material selected must be non-silicone rubber. In addition to meeting the needs of the aerospace industry for sealing, silicone rubber can absorb impact and damp vibrations (NVH, Noise, Vibration, and Harshness) while sealing, reducing unnecessary movement and noise and helping ensure passenger safety. In addition, the electrical insulation properties of silicone rubber also enable aerospace electronic equipment to operate stably, eliminating the hidden worries of precision instrument failures.

Automotive industry

Due to the properties of silicone rubber match the needs of the automotive industry in many ways, it is widely used in the automotive industry. The temperature of the car engine will fall around 80~90°C, and the high temperature resistance of silicone rubber around 200°C makes it very suitable as an internal part of the car body. At the same time, silicone rubber also has excellent compressibility, and it is often used as automotive gaskets and O-rings. In the current EV sector, silicone rubber is also widely applied in heat-dissipation flame-retardant gaskets for battery modules, high-voltage wiring harness sleeves, and sealing protection for vehicle display panels.
〈Extended reading: The Future of Liquid Silicone in Automotive Applications〉
 

Electronic industry

The most common of remote control buttons are made of silicone rubber. The good elasticity of silicone rubber brings longer service life to related button devices, and the characteristics of silicone rubber itself are non-toxic, skin-friendly and waterproof, so that silicone rubber can be used in instrument panels, buttons, and dustproof gaskets. There are excellent applications in other fields. In addition, although it is not often seen in practice, silicone conductive strips, which play a key role in circuit boards, displays, screens, etc., have better wear resistance than traditional conductive devices, and are also a major application in the electronics industry.
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Food contact industry

In the past, when silicone rubber was not popular, the food industry mostly used plastic or other rubber container storage materials, but the color of the container even faded after use. The rise of silicone rubber has made up for the needs of food safety. It is non-toxic to the human body and has good weather resistance. Using sterilization methods other than ultraviolet rays, it can be reused and maintain the original state of the product. It is not difficult to see its traces in the food industry. Such as seals, silicone rubber tubes, etc.
〈Extended reading: What is Food Grade Silicone? A Guide to Safety and Applications〉
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Hardness and Physical Properties of Elastomeric Silicone

Hardness (durometer) is one of the key physical indicators when selecting silicone rubber, typically measured using the Shore A scale. Silicone rubber offers a wide hardness range, usually from 10 Shore A to 80 Shore A. Different hardness levels affect compressibility, sealing performance, and processing difficulty:

• 10A–30A (Soft): Silicone rubber in this range has a gel-like or very soft texture, offering excellent elongation and elasticity. It is suitable for delicate sealing applications requiring very low closing force, vibration-damping pads in high-vibration environments, and medical devices that come into contact with skin.

• 40A–60A (Standard): This is the most commonly used hardness range in industrial applications. It provides a good balance between tensile strength, tear resistance, and elasticity, making it ideal for O-rings, custom seals, membrane switches, and general protective components.

• 70A–80A (Hard): Products in this range are relatively rigid, with excellent wear resistance and extrusion resistance. They are suitable for high-pressure hydraulic sealing systems, load-bearing spacers that must retain structural shape, and mechanical components requiring higher hardness.

〈Extended reading: Cultivating a Deeper Understanding of Silicone Hardness〉
 

How to Choose the Right Elastomeric Silicone? Advantages and Limitations

Advantages of Elastomeric Silicone

In demanding industrial environments, engineers often choose silicone rubber because it offers superior physical and chemical performance compared to other materials:

• Wide temperature resistance: Maintains elasticity and structural integrity in extreme environments ranging from -60°C to +230°C. Special formulations can even withstand instantaneous temperatures up to 300°C, which most organic rubbers cannot achieve.

• Excellent weather and aging resistance: Resistant to UV, ozone, moisture, and harsh environmental conditions. It does not easily crack, harden, or degrade even after long-term outdoor exposure.

• Outstanding electrical insulation: Maintains high and stable dielectric strength under high voltage, high frequency, and extreme temperature variations, making it ideal for electronic components.

• Low permanent deformation: Retains excellent rebound properties after long-term compression, ensuring reliable sealing without leakage over time.

• Non-toxic and safe: Free of plasticizers, odorless, and inherently resistant to bacterial growth. It can comply with strict standards such as FDA and LFGB for food and medical applications.

Limitations of Elastomeric Silicone

Despite its excellent properties, certain physical limitations should be considered during engineering design:

• Lower mechanical strength and tear resistance: Compared to natural rubber or polyurethane (PU), standard silicone rubber has weaker tear and abrasion resistance, making it less suitable for high-friction or sharp mechanical environments.

• Limited chemical resistance: Performs poorly against strong acids, strong alkalis, concentrated steam, petroleum-based fuels (e.g., gasoline), and certain organic solvents (e.g., toluene). Exposure may cause swelling and reduced strength. For oil resistance, fluorosilicone (FVMQ) is recommended.

• Higher gas permeability: At room temperature, silicone rubber has higher gas permeability than butyl rubber or NBR, making it less suitable for ultra-high vacuum or high-pressure gas sealing systems.

FAQs About Elastomeric Silicone

What temperature can silicone rubber withstand?

General industrial-grade silicone rubber can withstand temperatures of 200°C to 230°C for long-term use, with special grades tolerating up to 300°C. Unlike conventional rubber, which may soften or become brittle around 100°C, silicone rubber maintains its elasticity and sealing performance in harsh environments such as ovens, engine compartments, and steam sterilization, without releasing toxic substances or undergoing chemical degradation.

Can silicone rubber be exposed to sunlight or UV?

Silicone rubber has excellent UV resistance and will not become brittle or crack. However, colored silicone may experience slight fading after prolonged exposure. Its molecular backbone is inherently resistant to UV and ozone, giving it a long service life outdoors. While pigments may degrade and cause discoloration, this does not affect its waterproofing or structural performance.

What is the difference between silicone rubber and regular rubber?

The most straightforward differences lie in temperature range and weather resistance. Silicone rubber significantly outperforms conventional rubber in both aspects. Standard rubber tends to harden and become brittle in low temperatures, soften at high temperatures, and crack after prolonged outdoor exposure. In contrast, silicone rubber maintains flexibility across a wide range (-60°C to 230°C) and remains stable and non-toxic even after many years outdoors.

Is silicone rubber oil-resistant?

Standard silicone rubber is not suitable for direct contact with petroleum-based fuels such as gasoline or diesel, as it may swell and deform. While it has moderate resistance to vegetable oils and some lubricants, it is not ideal for fuel or strong chemical environments. For applications requiring high fuel resistance, fluorosilicone (FVMQ) is a better choice.
 

Conclusion

After our introduction, do you have a better idea of the difference between silicone rubber and rubber? Silicone rubber and rubber have similarities, but they are more different from each other. As a more environmentally friendly material, silicone rubber has attracted more attention than ever before. In order to find high-quality silicone rubber materials, it is necessary to pay attention to the raw materials used in the production of silicone rubber. GSUN adopts international silicone raw material manufacturers, such as Shin-Etsu from Japan, Wacker from Germany and DOWSIL from the USA. It is our insistence to check the raw materials for customers. And in order to take full responsibility for our customers, we provide one-stop service to ensure that every link of silicone rubber production is strictly checked to meet your needs. If you require silicone rubber OEM/ODM services, feel free to contact GSUN right away for professional consultation and customized services!
〈Extended reading: How to Choose a High-Quality Silicone Manufacturer? 4 Key Evaluation Factors + A Complete Guide to the Collaboration Process〉