A beginner’s guide to elastomer properties and applications
Elastomer is a term that’s frequently interchanged with rubber despite it being a rubber alternative. Its applications have expanded to include use in the general rubber industry along with the chemical and automotive industries.
What are the properties of elastomer?
Its properties can be summed up as durable, flexible and reliable. These three characteristics are important for all elastomer applications, but variations focus on other strengths depending on what the elastomer is being used for. Generally, they need to be able to withstand high temperatures and exposure to chemicals so that they can be used in place of metal in a manufacturing context.
Flexibility is extremely important in elastomers. They often need to be stretched to twice their original length while being able to return to their original size undamaged. This resilience is extremely important when flexibility is required in the manufacturing process. Combined with resistance to high temperatures, this makes flexible elastomers suitable for cables, adhesives, clothing and hoses such as those required by a silicone hose manufacturer.
Each elastomer is made with potential properties in mind that influence its composition. The polymer determines the heat and chemical resistance, and a reinforcer such as carbon is then added for strength. Other materials are added, such as anti-oxidants, flame retardants, accelerators and curatives. A plasticiser is used for low temperatures. Mixing the ideal quantities will impact the properties of the polymer.
Properties and performance also depend on the curing process. It is generally done at a high temperature to create long-chain polymers that crosslink to give the elastomer its elasticity and flexibility. Some elastomers are thermoplastic and will melt into a liquid state, turning brittle when cooled.
Applications depend on the outcome of the manufacturing of the elastomer but can be broadly divided into performance ranges.
Extrusion is used in wire, tubes and hose-making silicone hoses. These are typically cured in a steam autoclave and then shaped.
Injection moulding uses high pressure to force a compound into a mould. This is suitable for high-viscosity elastomers. They are suitable for low-temperature applications and boast an excellent resistance to engine oil. They are also used in aerospace technology and the automotive industry.
Ethylene Methyl Acrylate copolymers are used almost entirely in the automotive industry.