Rubber Materials

Rubber is an excellent multi-functional and hard wearing material that can be extruded, moulded and cut into an endless variety of shapes. With over 40 types of rubber and plastic compounds available, it is possible to select the type most suitable for the required application. Different industry sectors have different demands and manufacturing your extrusion or gasket in the correct material is essential for providing a long lasting sealing solution.

For many years, rubber was only available in natural forms harvested from trees and plants. Over the last century, man-made rubber compounds such as EPDM, Neoprene and Nitrile were developed by vulcanising and experimenting with petroleum by-products. Although there are over 40 different types of rubber compounds, they can all be categorised within three different areas; natural rubber, synthetic rubber and silicone.

Natural rubber is made by extracting latex from trees and some plants. There are over 2,000 different types of tree that produce latex, but the Hevea brasiliensis tree which can grow over 43 metres tall, is the most common. Latex is obtained by tapping the tree by making a cut in the bark and harvesting the liquid sap. This is then processed into a usable natural rubber compound which can be used for extruded seals and rubber strips.

Natural rubber is an excellent material for applications that require high elasticity and tensile strength. It has great compression recovery so can reliably be used for seals with large closing and compression forces. Unfortunately, due to the way natural rubber is manufactured, it is often more expensive compared to synthetic alternatives. It is also recommended that natural rubber seals are installed in environments that are not subjected to excessive amounts of UV radiation. Natural rubber is not UV stable so will start to degrade, lose elasticity and form cracks if used in natural light environments.

Unlike natural rubber, synthetic rubber does not occur naturally and is man-made using petroleum by-products. The procedure to manufacture a synthetic rubber compound follows a very similar process differing ever so slightly for the particular type of material. The production process combines a hydrocarbon mixture with natural gasses. This process produces monomers which bind together to create polymers before being formed into a rubber compound through the addition of chemical agents. These rubber compounds can then be used to create rubber seals and extrusions.

Synthetic rubbers copy most of the properties of natural rubber but can be used with higher temperatures and are often oil and chemical resistant. The large amount of synthetic rubbers available makes it easy to find a material suitable for the desired application. Whether that is resistance to petroleum based oils and fuels, extreme temperatures or weathering. Most synthetic rubbers are available in either sponge or solid forms, and can be supplied as extruded profiles, moulded gaskets, or cut into strips and sheet.

Silicone rubber, being a synthetic polymer made from silicon, sits outside of its natural and synthetic rubber counterparts. Silicon is the raw chemical element which when heated to 1800°c, combined with methyl chloride and distilled forms a raw silicone compound. This compound can then be used for making extrusions, sealants or lubricants.

Silicone rubber can be supplied as extruded profiles, moulded gaskets, or cut in strips and sheets. It is an excellent material for applications that require a good compression set or will be subjected to extreme environments and temperatures between -55 °C  and 300 °C. Silicone can also be pigmented to virtually any RAL colour so is often the material of choice for rubber seals that will be used in food safe environments, need to match your company's branding or be a vibrant colour for hazard identification. The main disadvantage of silicone is that it has poor abrasion resistance and can tear if it comes into contact with a sharp object

Elastomers come in many different grades and are used extensively in a wide range of industrial and domestic applications. With over 50 years of experience in the rubber sealing industry, Seals Direct has developed long-standing relationships with rubber compounders. We have access to over 40 different types of rubber and plastic compounds and are happy to provide advice on the most suitable material for your application.  The majority of our rubber materials are available in sponge or solid forms and can be supplied as extruded profiles, gaskets or cut in sheet or strip form.

Products made from sponge or solid rubber can be manufactured from a wide variety of materials. This selection allows you to choose a suitable compound that allows for any environmental, chemical or temperature demands of the required application.