FAQs

General Silicone Questions

What is silicone?

Silicone is a man-made polymer derived from silicon metal. Its unique composition offers significant advantages over conventional rubber types and is available in forms such as rubbers, greases, and fluids. If you want to learn more about Silicone then read our introduction to Silicone.

Does the outside environment affect silicone?

Silicone is highly resistant to extreme weather conditions, including intense heat, cold, dryness, humidity, or wetness. It also has excellent UV and ozone resistance which prevents degrading. We cover this more in-depth in our ‘Which rubber is best for your application?’ news article.

Silicone seems to be more expensive than other rubber; why is this?

Silicone costs more than other rubber types because it is a specialised, high-performance material with exceptional properties. Its manufacturing process is intensive and intricate, requiring advanced equipment, and it is produced in smaller quantities compared to other polymers. We look into why Silicone seems to be more expensive than other rubbers in this news article.

In what colours is silicone available?

Silicone can be produced in an extensive range of colours, including vibrant fluorescents, metallic shades, and heat-sensitive options that change colour with temperature shifts. Colour matching is also common with solid silicones to specific RAL numbers.

What equipment do I require to process silicone compound?

Silicone compounds are compatible with most standard rubber processing machines and equipment. If you would like to see these in action give our Millroom tour video a watch!

What is the shelf life of a silicone product?

The shelf life of silicone compounds varies depending on how they are processed and more importantly stored. Over time, they may stiffen, but this can often be resolved by refreshing them on a two-roll mill. Typically, silicone compounds have a minimum shelf life of six months.

How do I store silicone compounds?

Store silicone materials in a dry environment, away from direct sunlight or heat, and ensure the temperature remains below 30°C.

How do I dispose of silicone rubber?

Silicone rubber, whether cured or uncured, is non-hazardous and can be disposed of following local waste management guidelines.

Is silicone toxic?

Silicone is regarded as a safe material with minimal toxic effects in most environments. It is not considered hazardous waste and can be safely disposed of according to local regulations.

Silicone Durability

What is the temperature range of silicone products?

One of silicone’s main advantages over other elastomers is it can function across a broad temperature range, from approximately -60°C to +200°C. We look further into this area in our news article ‘What Temperatures can Silicone Rubber Withstand?’

Is silicone volatile?

While silicone is generally stable, it may lose a small amount of weight as the temperature increases.

Is silicone thermally conductive?

Silicone can be made thermally conductive by adding specific chemical components.

Is silicone electrically insulating or conductive?

Silicone is naturally an electrical insulator, but it can be modified to conduct electricity by incorporating specific chemical components.

Is silicone rubber flame retardant?

Silicone has flame retardant properties and is one of the more robust elastomers for flame resistance. Silicones can be made more flame retardant by adding specific chemical additives to help with resistance to flame. Learn how we test fire resistance in our Understanding UL94v-0 news article.

Is silicone suitable for underwater submersion?

Silicone is not negatively affected by immersion in fresh or saltwater, making it suitable for underwater use. In a sealing capacity, silicone foam or sponge can also be suitable for under water submersion but checking the material’s cell structure and water absorption data is important to ensure the grade is suitable for an underwater environment.

Can I paint on silicone?

Silicone is inherently resistant to paint. Although special surface treatments can enhance paint adhesion, painting silicone products is generally challenging.

Silicone Uses

Can silicone be used in cleanroom environments?

Yes, silicone is well-suited for cleanroom environments, as it does not support the growth of micro-organisms due to its inorganic makeup.

Is silicone safe for applications involving rapid decompression?

Due to its high permeability to gases, silicone may not be ideal for uses requiring rapid decompression.

What environment is silicone rubber NOT suitable for?

Standard silicone is unsuitable for environments involving contact with fuel based oils, petroleum and solvents. However, fluorosilicone performs well in such conditions. Silicone also has limited resistance to steam and superheated water. If you are still wondering which rubber is right for your application read our guide!

Why is silicone used in food applications?

Silicone is regarded as a safe, low-taint material suitable for food-contact applications, making it a preferred choice in food and beverage production. Find out all about our FDA food grade Silicone and what it is made of.

Is silicone safe for baby products?

Specific silicone grades are widely used in baby bottle teats due to their cleanliness, durability and resistance to high heat sterilisation.

Technical Questions

Why are some silicones specified as “addition cure”?

“Addition cure” silicones require a catalyst to trigger a reaction between the components of the compound. This mechanism allows them to cure, hence the name. These compounds can come in one-, two-, or three-part systems. If you are interested in what post curing is and how it affects Silicone then give our News article a read.

How long does it take to cure silicone?

The curing time for silicone depends on a number of factors such as temperature, thickness, and the type of curing process. Generally, a compression-moulded silicone part takes around 5 minutes to cure at 180°C.

What is the difference between ‘curing’ and ‘vulcanisation’?

The terms curing and vulcanisation both refer to the same process: transforming the polymer into a cross-linked, elastic material. We cover this in more detail in our News article ‘Difference between ‘curing’ and ‘vulcanisation’?’

Does silicone release PCBs during curing?

Certain silicone compounds, especially those used in extrusion, may release trace amounts of PCBs due to the peroxide used in cross-linking. Adequate ventilation and extraction are recommended in processing areas.

Can I ‘bond’ other substrates to silicone rubber?

Yes, silicone can be bonded to materials like metals and plastics using specific primers and surface preparation methods. We look at the various different methods and primers in our news article ‘How Easily Does Silicone Stick to Different Surfaces?’

Can you make silicone change colour with temperature?

By incorporating thermochromic pigments, silicone can be designed to change colour with temperature.