What is Silicone Rubber?
Silicone rubber is a high-performance synthetic elastomer known for its unique combination of physical and chemical properties including excellent temperature resistance, chemical resistance and the ability to perform within harsh industry environments. Silicone rubber is manufactured from silicon, carbon, hydrogen and oxygen molecules.
- There are many grades of silicone rubber such as: FDA Approved Silicone Rubber, Silicone Sponge Rubber, HT800 Silicone Sponge Rubber, MF775 Silicone Rubber, Metal Detectable Silicone Rubber, Electrically Conductive Silicone Rubber and Fluorosilicone Rubber, among others.
- Silicone rubber offers excellent properties including high temperature resistance, chemical and weathering resistance, good physical properties, FDA approval and impressive durability.
- Silicone rubber is used in professional industry environments worldwide for many different applications. Some of the most common industries include: Aerospace & Defence, Automotive & Rail, Electronics, Food & Beverage, Medical and Construction.
- Silicone rubber is popular because of its unique benefits, often not found with other elastomers. These include an extreme operating temperature range, chemical resistance, water resistance, weathering resistance, electrical insulation and outstanding longevity of life.
- Delta Rubber Limited stock and supply a range of silicone rubber grades at our online shop, available in different forms such as sheet, rolls, cut rubber strip, gaskets, washers and more to suit almost any application.
History of Silicone Rubber
Silicone rubber was first developed for commercial use in the 1930s by J.F Hyde who discovered that silicone polymers could be formed by reacting silicon and methyl chloride gas in the presence of a platinum catalyst. Hyde’s work was developed further in 1940 by English scientist F.S Kipping who was the first person to use the name ’silicones’. At this stage, Kipping saw no practical use for the material and referred to it as a ‘sticky mess’. Today, Silicone is the go-to polymer for many professional industry applications, due to its outstanding properties and versatility.
Grades of Silicone Rubber
There are many grades of silicone rubber available to meet specific needs and applications including:
- FDA Approved Silicone Rubber
- Silicone Sponge Rubber
- HT800 Silicone Sponge Rubber
- MF775 Flame Retardant Silicone Rubber
- Electrically Conductive Silicone Rubber
- Metal Detectable Silicone Rubber
- Fluorosilicone Rubber
Each grade has specific properties and benefits, making it suitable for different industries and applications.
It is important to understand the different grades of silicone rubber to ensure the correct material is used for a specific application. The properties of silicone rubber vary depending on the grade and can affect its suitability. Therefore, careful consideration must be given to the choice of material to ensure that the desired properties are achieved
Why use Silicone Rubber?
Silicone rubber is used mostly because of its versatility and ability to perform within different environments, making it an excellent choice for various industrial applications. Different grades of silicone rubber have varying degrees of properties and benefits, therefore it is essential to understand which grade to use for specific applications. But what are some of the key properties of silicone rubber?
- Temperature Resistance: Silicone rubber is well-known for its exceptional temperature resistance properties, making it suitable for use in extreme temperature environments. It can maintain its mechanical and physical properties at temperatures ranging from -60°C to 260°C (depending on the grade selected). This temperature resistance makes it a popular choice in industries such as aerospace, automotive, and construction, where components need to withstand extreme temperatures on a frequent basis.
- Physical Properties: Silicone rubber has excellent physical properties, including high flexibility and elasticity, good tear resistance, and low compression set. It also has a low modulus of elasticity, which means it can deform without breaking or cracking. These properties make it an ideal material for use in gaskets, seals, and O-rings that require excellent sealing and pressure resistance.
- FDA Approval: Certain grades of silicone rubber are approved for use by The Food and Drug Administration (FDA), making it a suitable material for food and beverage processing applications. It is also biocompatible and safe for use in medical applications such as implants, tubing, and surgical tools. The FDA approval and biocompatibility of silicone rubber make it a popular choice in these industries, among others.
- Resistance Properties: Silicone rubber has exceptional resistance properties, including resistance to chemicals, water, and weathering. It is also resistant to ozone and UV radiation, which can cause degradation to other elastomers. These resistance properties make it ideal for use in harsh environments, such as chemical processing plants, where components must withstand exposure to corrosive chemicals and fluids.
- Durability: Silicone rubber is known for its durability and longevity of life, making it an ideal material for use in applications that require components to last for extended periods. Its resistance to degradation from UV radiation, ozone, and weathering means that components made from silicone rubber can withstand exposure to the elements without losing their mechanical and physical properties.
What is Silicone Rubber used for?
Silicone rubber is used by many industries due to its excellent properties. Let’s explore exactly how silicone rubber is adopted in various industries, looking into specific applications where different grades of silicone rubber can be used.
Silicone rubber is a popular material for use in the aerospace and defence industries due to its excellent temperature resistance properties. Frequently used for components such as gaskets, seals, and O-rings, it can withstand extreme temperatures and maintain its elasticity after prolonged use. Specific grades of silicone including electrically conductive silicone rubber, MF775 silicone rubber, fluorosilicone rubber and HT800 silicone sponge rubber are among the most common grades used for aerospace and military applications. This is due to their higher temperature resistance or ability to perform when exposed to volatile fuels or chemicals.
Automotive & The Rail Industry:
The automotive & rail industry utilises silicone rubber in various applications such as gaskets, seals, hoses, and vibration dampening components due to its high-temperature resistance and chemical resistance properties. Specific grades such as silicone sponge rubber, electrically conductive silicone rubber and HT800 Silicone are used in automotive applications for noise reduction, thermal insulation, and electromagnetic interference (EMI) shielding. In the rail industry MF775 has been designed specifically for London Underground applications and offers fire retardancy capabilities, making it certified for use on passenger carrying trains.
Silicone rubber is widely used in the electronics industry due to its electrical insulation properties. Electrically conductive silicone rubber is used for EMI shielding and grounding in electronic applications. Meanwhile, silicone sponge rubber and HT800 silicone grades are used as a thermal insulation material for electronic devices.
Food and Beverage Industry:
Our standard Silicone rubber is FDA approved, making it a suitable material for food and beverage applications. It is used in food processing equipment such as gaskets, seals, hoses, and tubing due to its ability to withstand high temperatures, resist chemicals, and avoid bacterial growth. Additionally, metal detectable silicone rubber is often used within the sector, predominantly for the process of preventing contamination.
Silicone rubber is widely used in the medical industry due to its biocompatibility and resistance to bacterial growth. FDA Approved silicone rubber is used in various medical applications such as implants, tubing, gaskets, and seals. It is also used in surgical tools and devices due to its durability and longevity of life. HT800 can also be used for medical equipment within the industry, as well as for shock and vibration reduction applications.
Silicone rubber is used in the construction industry due to its ability to resist extreme temperatures, chemicals, and weathering in general. It is used in applications such as sealants, adhesives, gaskets, and O-rings. The construction industry uses a range of Silicone grades including FDA Approved silicone, Silicone sponge for applications where the ability to compress is required and MF775 for the construction of the London underground.
Benefits of Silicone Rubber
Silicone rubber offers many benefits not found with other materials, such as high temperature resistance, chemical resistance, water resistance, resistance to weathering, electrical insulation and longevity of life. This section will explore the benefits of silicone rubber in more detail, providing an insight into specific benefits of each grade.
Temperature Resistance is one of the primary benefits of silicone rubber. It has a wide operating temperature range from -55°C to +260°C (depending on the grade chosen), making it suitable for use in extreme temperature environments. Although Silicone rubber offers a broad operating temperature range in general, HT800 silicone foam rubber, electrically conductive silicone and fluorosilicone rubber are specially formulated grades for high-temperature applications, making them ideal for use in industries such as aerospace, automotive and for electrical equipment.
Chemical Resistance is a critical property of silicone rubber. It has excellent resistance to many chemicals, oils, and solvents, which makes it ideal for use in harsh chemical environments. MF775 flame retardant silicone rubber, electrically conductive silicone rubber and FDA approved silicone rubber grades offer the best chemical resistance properties.
Water resistance is a benefit of both silicone sponge rubber and HT800 silicone rubber, this is due to the materials closed-cell structure, preventing water absorption and providing excellent sealing properties. These grades are suitable for applications where water resistance is required including outdoor and marine applications for gaskets, seals and weatherstripping.
Resistance to Weathering:
Silicone rubber is resistant to weathering in general and won’t be affected by sunlight, ozone, ultraviolet light, corona discharge, cosmic radiation, ionising radiation and natural gases that may cause other elastomers to deteriorate.
Electrically conductive silicone rubber is specially formulated to provide excellent electrical conductivity and insulation properties. It is ideal for use in applications such as EMI shielding, electrical connectors and cable insulation. Additionally, HT800 silicone and silicone sponge rubber offer the ability to thermally insulate electronic devices and equipment.
Longevity of Life:
All grades of Silicone rubber offer excellent longevity of life in comparison to other elastomeric materials, this is due to silicones ability to resist chemicals, water and weathering in general. The material holds excellent physical properties, allowing it to perform consistently within harsh environments. This makes silicone rubber the go to choice of elastomer for applications where long-term performance is required, such as in the aerospace or automotive sectors.
What are the different types of Silicone Rubber?
There are various types of Silicone rubber materials, each offering different properties, applications and benefits. Understanding the difference between each silicone rubber grade is critical, allowing you to make an informed decision as to which material will be suitable for your project.
Our most popular grade of silicone rubber, offering a cost-effective silicone solution suitable for many different applications. The material is FDA certified for use in food and beverage processing and WRAS approved for use with portable water. FDA approved silicone rubber has excellent resistance to ozone, oxidation, UV light, corona discharge, cosmic radiation, ionising radiation and weathering in general.
- Temperature Range: -60°C to +230°C
- Hardness: 60°±5 Shore A
- Tensile Strength: 7.9 Mpa
- Elongation at break: 340%
Silicone sponge rubber is a closed-cell foam material that is resistant to water and offers the ability to compress between two surfaces. For these reasons, it’s a popular choice for sealing applications. Silicone sponge rubber is resistant to ozone, oxidation, UV light, weathering in general and can be used outdoors.
- Temperature Range: -60°C to +200°C
- Hardness: 42°±5 Shore A
- Tensile Strength: 0.6 Nmm2
- Elongation at break: 145%
HT800 silicone sponge rubber is a specialist and highly versatile, medium firmness silicone that offers the lightness and compressibility of foam, with the enhanced sealing capabilities of sponge rubber. The material is flame retardant and offers resistance to weathering, ozone, UV and extreme temperatures, making it suitable for use in all environments.
- Temperature Range: -55°C to +200°C
- Hardness: /
- Tensile Strength: 310 kPa
- Elongation at break: 80%
A superior grade of silicone rubber, MF775 is a fire retardant compound exhibiting low smoke and low toxicity characteristics, specifically designed for use in the mass transit industry. MF775 silicone rubber is recommended for enclosed environments where fire safety is a primary concern and has been certified for the design and construction of passenger carrying trains.
- Temperature Range: -70°C to +250°C
- Hardness: 68°±5 Shore A
- Tensile Strength: 9 Mpa
- Elongation at break: 270%
Electrically conductive silicone is a premium grade silicone, offering the perfect balance between electrical conductivity (low amperage conductor) and protection against electrostatic discharge. The material is filled with carbon particles and offers an excellent operating temperature range, making it suitable for high temperature sealing applications.
- Temperature Range: -62°C to +260°C
- Hardness: 70°±5 Shore A
- Tensile Strength: 700 psi
- Elongation at break: 200%
Metal detectable silicone rubber is manufactured from FDA approved ingredients and features iron power to aid in the identification of foreign particles within the food processing and pharmaceuticals industry, preventing overall contamination of products. The material is also resistant to weathering, UV and Ozone damage.
- Temperature Range: -60°C to +200°C
- Hardness: 60°±5 Shore A
- Tensile Strength: 7.0 N/mm2
- Elongation at break: 400%
Fluorosilicone Rubber is a high-performance silicone grade, offering superior resistance to fuels, oils, solvents and harsh chemicals. The material is the perfect choice for gaskets and seals in harsh industry environments such as the aerospace or military sectors. Fluorosilcone has an excellent operating temperature range and also resistance to weathering, UV and Ozone.
- Temperature Range: -60°C to +260°C
- Hardness: 63°±5 Shore A
- Tensile Strength: 7.3 Mpa
- Elongation at break: 319%
Where can you buy Silicone Rubber?
Delta Rubber Limited stock and supply standard and specification Silicone rubber grades from stock including FDA Approved Silicone Rubber, Silicone Sponge Rubber, HT800 Silicone Sponge Rubber, MF775 Silicone Rubber, Electrically Conductive Silicone Rubber, Metal Detectable Silicone Rubber and Fluorosilicone Rubber. We offer these materials manufactured in different forms to suit our clients applications such as Rubber Sheet, Cut-Rubber Strip, Washers, Gaskets, Seals, Extrusions & Tubing.
- FDA Approved Silicone Rubber – Available in sheet form in thicknesses from 1mm to 6mm thick (other thicknesses available upon request), sheet sizes measuring 1.2 metres wide and in any length from 1 metre to a full 10 metre roll. Also sold in 5 metre lengths of FDA approved solid silicone rubber strip, manufactured to your desired widths if required.
- Silicone Sponge Rubber – Sold online in cut rubber strip form for customer convenience, in thicknesses from 1.5mm to 6mm thick (other thicknesses available upon request), your desired widths from 10mm to 50mm wide and in standard 5m lengths. Self-adhesive silicone sponge rubber options are available for ease of installation.
- HT800 Silicone Sponge Rubber – Both HT800 silicone sponge sheet and cut strip are available from stock. HT800 silicone sponge sheet is sold in thicknesses from 0.8mm to 3.2mm thick, standard sheet sizes measuring 915mm wide and lengths from 1 metre to a full 10 metre roll. HT800 silicone sponge strip comes with self-adhesive backing as standard, widths from 10mm to 50mm wide and standard lengths of 3 metres.
- MF775 Silicone Rubber – Flame retardant MF775 silicone rubber sheet is sold in a choice of sheet sizes (500mm or 1000mm wide), thicknesses from 1.5mm to 3mm thick (other thicknesses available upon request) and lengths of 1 metre. For MF775 silicone rubber strip, choose your width from 50mm to 250mm wide and purchase standard 1 metre lengths.
- Electrically Conductive Silicone Rubber – Electrically conductive silicone sheet is available in varying thicknesses from 0.5mm to 3mm thick (other thicknesses available upon request), sheet sizes 500mm wide and any length from 2 metres to a full 10 metre roll.
- Metal Detectable Silicone Rubber – Our buy-online blue metal detectable silicone rubber sheet is sold in any length from 1 metre to 10 metres, thicknesses from 1.5mm to 3mm thick (other thicknesses available upon request) and 1.2 metre widths.
- Fluorosilicone Rubber – All blue Fluorosilicone rubber sheets have a thickness of 3.2mm and are available to purchase in pre-cut sheet sizes measuring: 500mm x 450mm, 914mm x 450mm, 1000mm x 450mm and 1000mm x 914mm.
Frequently Asked Questions (FAQ’s)
What is the difference between silicon and silicone rubber?
The difference between silicon and silicone is that silicon is a natural chemical element, whilst silicone is a man made polymer created from silicon.
Is silicone rubber strong?
Silicone rubber is an extremely strong polymer. Different grades of Silicone rubber offer varying tensile strengths and some grades can stretch up to 400% their original size before breaking.
What material is silicone rubber?
Silicone rubber is a high performance synthetic elastomer manufactured from silicon, carbon, hydrogen and oxygen molecules.
Is silicone rubber FDA approved?
Many silicone rubber grades are approved for use by the FDA. We recommended checking whether your chosen silicone grade is FDA certified before use.
What is the disadvantage of silicone rubber?
One of the main disadvantages of silicone rubber is the cost. Due to the materials unique properties and manufacturing process, it can be costly in comparison to other elastomeric materials. However, this cost is justified, given the longevity of life offered by silicone rubber.
Is silicone good for rubber gaskets?
Silicone rubber is a good choice for rubber gaskets due to its excellent properties such as; operating temperature range, chemical resistance, weathering resistance and durability.
Can silicone rubber be recycled?
In the United Kingdom silicone rubber is approved to be recycled for repeated use. However, the recycling process requires the material to be ground and therefore you cannot put silicone rubber in a normal recycling bin.