Heat Proof Silicone Adhesive
Heat proof silicone adhesives are used for applications that will be exposed to high temperatures. These include automotive gaskets and engines. These high temperature silicones seal valve covers, axle housings and water and oil pump seals.
This one part acetic cure silicone is economical and ideal for general construction, sealing, glazing and bonding jobs. It withstands to 180degC (ongoing) and is long lasting.
1. High Temperature Resistance
The chemical structure of silicone keeps it stable in high temperatures, making it a popular choice for bonding and sealing areas that will be exposed to extreme temperatures. Heat resistant silicone can withstand a wide range of temperatures, from -60°C up to +230°C and still be flexible.
To apply, clean the surfaces to be sealed thoroughly to remove any dirt and grease. Cut the nozzle of the sealant tube at a 45-degree angle and using your caulk gun, apply a bead along the seam to be sealed, smoothing with a tool or damp cloth, or your gloved finger, as required.
Many types of silicone adhesives are available, depending on what is needed for your application. You can choose from one component systems that require no mixing and cure at room temperature, to acetoxy or neutral curing silicones, which release less corrosive entities as they cure, so can be used with electronics. There are also fire retardant silicones, able to resist chemicals, water, weathering and UV, so are ideal for use in flanges of stoves, boilers, flue gas systems, heating installations and ductwork.
2. High Adhesion
Heat resistant silicone adhesive has very high adhesion to a variety of materials including clean metals, glass, most types of woods and ceramics. It is also resistant to moisture, chemicals and weathering. Although it isn’t a weight-bearing sealant, it can be used around showers, sinks and bathtubs, keeping water out to avoid mildew build up.
It can withstand temperatures up to 300°C, and some varieties can resist direct exposure to flames. It is often used as an insulator, protecting components from temperature fluctuations and electrical currents.
Silicone adhesives are available in a variety of formulations to suit specific projects. They can be cured with UV or radiation, by using air humidity, two component systems that require mixing or as one part systems with no additional curing agent. They can also be formulated to be corrosive, insulative or chemically resistant.
Weicon has several different grades of heat proof silicone adhesive, all of which have high adhesion and can withstand high temperatures. Flex 310 M Classic is a grey, neutral cure silicone adhesive that can be used on surfaces such as glass and aluminium. Alternatively, Weicon’s VS-K 1500 is a black, acetic cure silicone that adheres to heat proof silicone adhesive most materials and is suitable for a range of applications from household, renovation and construction work.
Silicone adhesives are flexible and can withstand a variety of temperatures. They can also relieve thermal stress between substrates that have different coefficients of expansion and contraction. This is a beneficial trait for many applications, especially in industrial settings where materials need to be durable and can withstand stressful and demanding conditions.
Another reason that silicone adhesives are so popular is their transparency when cured. This allows them to blend in and not affect the aesthetic appearance of a product. This is particularly helpful for medical products that require a strong bond but cannot be noticed, such as pacemakers and hydrocephalus shunts.
The manufacture of silicone adhesives begins with isolating silica from minerals like quartz and sand. The material is then separated into disilanol and hydrochloric acid to form polydimethylsiloxane. This is then polymerized to create a rubber based adhesive.
4. Resistance to Corrosion
Silicone adhesives are a very durable material, with high resistance to corrosion and degradation over time. They can withstand very high temperatures, and can be used on a wide range of surfaces including metals and glass. This makes them ideal for a variety of applications, from automotive to medical applications.
RTV silicones are made up of a polymer called siloxane. This consists of a long chain of alternating silicon and oxygen atoms, heat proof silicone adhesive found naturally in sand. Silicones are also very flexible, able to stretch many times over and return to their original form. This flexibility is a huge advantage for many applications, especially in environments where the materials can expand and contract over time.
When using RTV silicones, it’s important to choose the right type for your application. Acetoxy cure silicones are very economical and provide good adhesion to non-porous surfaces, but can corrode some metals and etch certain plastics. Neutral cure silicones, on the other hand, release a neutral/non-acidic byproduct and can be used on metals and most plastics. They take longer to cure, but are ideal for use on hot engine parts, such as valve covers and oil pump seals.
5. Environmentally Friendly
The versatility of silicone adhesives means they are used for a wide range of applications. They are also able to withstand many different environmental conditions. This includes exposure to heat and extreme weather. This makes them an ideal choice for industrial applications.
Silicone is produced from a natural source, silica. This is found in various minerals, such as quartz and sand. The process of isolating this substance involves crushing and grinding the raw materials. This is followed by water washing and flotation. This allows the removal of impurities, which are then ground into a fine powder.
This is then mixed with other ingredients to create the adhesive. Platinum is often added to accelerate the curing process. However, this is a precious metal, which has led to concerns over resource depletion. A new curing catalyst has been developed that uses less platinum, which is a positive step towards resource conservation. It is also able to be used at lower temperatures, meaning that it can be used in a wider range of applications. This is particularly good news for those involved in medical applications, as silicone adhesives are chemically inert and safe to use when bonding surfaces that will come into contact with patients.