In today’s elastomer market, the choice of rubbers available to engineers and designers is vast. The sheer number of choices can often cause confusion as to which rubber to select for certain applications. Properties such as temperature resistance, compression set, tear strength and elongation may not be fully understood, which therefore effects making the correct choice of rubber.
Here we discuss why engineers choose silicone rubber as a material over other rubbers and the benefits the elastomer has when in applications.
Firstly we must outline that all rubbers have both positives and negatives depending on application conditions and as of yet, there is not one rubber that ‘ticks all the boxes’. So this leaves us with the realistic conclusion that we must delve into the application where the rubber will be used to understand what stresses the material will face and then give a decision.
As we’re a silicone rubber manufacturer we hold a vast amount of knowledge in the heat cured silicone arena so let’s discuss the most common features and benefits of silicone to allow you to understand why engineers choose the material.
Temperature
Silicone is most commonly associated with its excellent resistance to extreme temperatures and this is generally one of the primary reasons silicone gets selected for application. We discussed temperature resistance in another blog post (http://silicone.co.uk/blog/temperatures-can-silicone-rubber-withstand/) as it is often a topic that causes some debate as to the maximum/minimum temperatures that silicone can withstand.
Some silicone manufacturers publish maximum temperatures of 300°C (572°) which looks impressive however, we know that silicone exposed to this constant temperature will last a matter of minutes which is not always explained on datasheets. It is true, silicone can withstand 300°C but this would be for short intermittent periods and is something that should be indicated to prevent failure in application. Our silicone can withstand consistent temperatures of 230°C (446°F) which in most cases is suffice in many high temperature applications. However, we do have our high temperature grade THT that can achieve a constant 270°C.
Environmental Resistance
Silicone rubber has excellent resistance to environmental conditions, making it the ideal material to be used for outdoor sealing applications that may be exposed to the elements. Silicone can withstand Ozone and UV stresses which allows the material to maintain its original properties and prevent degradation. Silicone also has excellent resistance against general weathering from rain, sleet, snow and frost allowing protection to electrical enclosures situated outdoors.
Low Compression Set
Another benefit of silicone (sponge in particular) is low compression set. Meaning that if the silicone is under compression for a length of time, it recovers and maintains its original shape. This is generally linked to a seal or gasket application that is often compressed, usually a door or enclosure that needs pressure applied to form a good seal. Once that door or enclosure is opened again the seal should return to its original shape and not become deformed.
To read an in-depth report on compression set, go to one of our blog posts where we explain in detail ‘why compression set is so important in the sealing world?’
Food Safe
Silicone is an inert polymer, meaning that it is mainly non-reactive. This makes it the go to elastomer in the food and beverage industry as it little to no effect on the products themselves. From dairy tubing to brewery hoses, Silicone Engineering’s silicone is widely used on a global scale. It is approved to FDA, BfR and WRAS standards which allow it to be in contact with food or beverages without causing contamination. Go to our Food & Beverage page to read more.
These are just some of the benefits silicone rubber can bring to applications when other elastomers fail. Silicone can resolve and/or prevent a number of sealing issues, which can increase the lifespan of a seal and also reduce replacement costs.
If you require any further information on our silicone rubber products, get in touch by asking one of our silicone experts today.