Elastomers are dimensionally stable plastics that can, however, be elastically deformed when cold. These plastics play such an important role in today's industrial production that it is well worth taking a closer look at them:
In the following, we would like to give you a brief overview of the various elastomers, their manufacture and use, and illustrate the importance of elastomers for industry and production.
An elastomer is often referred to colloquially as rubber, regardless of its exact chemical structure. This linguistic inaccuracy is probably the result of the fact that all elastomers have a number of distinctive properties in common. This linguistic inaccuracy probably results from the fact that all elastomers have some distinctive properties in common:
Good moldability: an elastomer can be permanently molded into almost any desired shape during production.
High elasticity: Elastomers can be deformed under the action of force.
Good dimensional stability: If the applied force decreases, the elastomer returns to its original shape.
Thermoplasticity: Elastomers can be processed warm and shaped into the desired form.
Thermal stability: Elastomers can be used within a wide temperature range.
Chemical diversity and variability: Elastomers can be synthesized from a large number of chemical components. The composition of these components determines the physical properties of the later product. The inaccuracy is probably due to the fact that all elastomers have some distinctive properties in common:
Good formability: an elastomer can be permanently formed into almost any desired shape during production.
High elasticity: Elastomers can be deformed under the action of force.
Good dimensional stability: If the applied force decreases, the elastomer returns to its original shape.
Thermoplasticity: Elastomers can be processed warm and shaped into the desired form.
Thermal stability: Elastomers can be used within a wide temperature range.
Chemical diversity and variability: Elastomers can be synthesized from a large number of chemical components. Their composition determines the physical properties of the later product.
Elastomers can be reversibly deformed under the action of mechanical force. Workpieces made of elastomer plastics can be stretched or squeezed. After the tensile or compressive load is removed, they return to their original shape. Only mechanical action is required for this deformation. The use of thermal energy is not necessary.
This special property is based on the wide-meshed linkage of the polymer chains within the plastic, which allows the chains to shift and move within certain limits. Once this limit has been exceeded, an effect occurs that can be mentally associated with a worn-out rubber band. Sealing washers and washers can also wear out under continuous load and eventually break.
Elastomers are dimensionally stable over a wide temperature range and retain their physical properties. Special adaptations in their chemical structure make it possible to produce special elastomers for low-temperature use. Likewise, it is possible to produce elastomers specifically for use in hot regions or production areas with high waste heat. Above the maximum operating temperature, elastomers can chemically decompose. Below the minimum operating temperature, they become brittle and lose their elastic properties.
The most prominent property of elastomers is their ability to absorb tensile and compressive stresses. Two factors can affect the elasticity of such a plastic:
Elastomers are by no means limited to conventional rubber made from natural rubber. There is now a whole range of other plastics that, in addition to elasticity, have additional properties that can be used in industry:
Elastomers made of natural rubber are characterized above all by high mechanical strength and elasticity. Their high resistance to abrasion should also be emphasized.
To date, natural rubber is an inexpensive material, but it has little resistance to UV radiation and ozone exposure. The resulting limitations in application led to the development of other elastomers.
Elastomers made of synthetic rubber are very heterogeneous from a chemical point of view. They consist of two or more different monomers that are linked together in a chemical reaction - polymerization. The exact composition of these monomers influences the physical and resulting mechanical properties of the finished product. The most important synthetic rubbers include:
Thermoplastic elastomers (TPE) combine the advantages of classic elastomers with those of thermoplastics. Thermoplastic elastomers behave like classic elastomers within the limits of their application temperature (usually in the range of room temperature). However, if they are exposed to heat, they begin to deform permanently. In this behavior, they resemble thermoplastics. Due to this property, TPEs can be welded, for example, to produce tight joints.
Liquid crystalline elastomers (LCE) combine the high formability of elastomers with the tensile strength and electromechanical properties of liquid crystals. Thus, the shape of these plastics can be changed by applying an electrical voltage. Areas of application for LCEs include:
Synthetic rubbers differ from one another, sometimes considerably, in terms of their physical properties. Commonly used synthetic rubbers include:
Acrylonitrile-butadiene rubber is produced from the monomers acrylonitrile and 1,3-butadiene. The physical properties of the elastomer are determined by the mixing ratio. NBR is characterized by the following properties, among others:
EPDM (ethylene-propylene-diene rubber) is a terpolymer of ethylene, propylene and any diene. This flexible chemical structure allows a wide range of variants. Consequently, EPDM can be used in a wide variety of applications. EPDM can be found in the following areas, among others:
EPDM has good ozone and UV resistance. It also has high thermal resistance. The chemical resistance to polar solvents is very high, but non-polar solvents such as fuels and oils attack EPDM.
Thermoplastics can also be deformed, but thermal energy is required for this. Thermoplastics are therefore not suitable as spring and buffer elements. For a better comparison, two important thermoplastics are briefly presented:
Polymethyl methacrylate (PMMA) is a thermoplastic also known as acrylic. PMMA is obtained by radical or anionic polymerization and then cast into crystal clear sheets.
PMMA is used in the following industries:
Learn more about PMMA as a versatile thermoplastic here.
Polyoxymethylenes (POM or also polyacetals) are thermoplastics that are mainly used for the production of molded parts by injection molding. POM is characterized by great hardness and rigidity.
Learn more about POM and its use here.
Due to the different chemical structure, no two elastomers are alike. This feature enables their use in numerous industries:
Elastomers, like all plastics, consist of so-called polymers, i.e. long-chain molecules composed of one or more different monomers. The formation of such a polymer takes place in a polymerization reaction. These include:
There is hardly an area of application in modern industrial and manufacturing technology in which at least one elastomer does not play a prominent role. These include:
By far the largest share of global elastomer production is used for the manufacture of tires. Styrene-butadiene rubber (SBR) and butadiene rubber (BR), which are characterized by low abrasion and low costs, are used here in particular.
Yoga mats, shoe soles, bicycle tires - no modern sport would be possible without elastomers. The plastics used here must be low-wear and must not trigger any allergies.
Dental technology, medical technology, molded part and prototype construction - hardly any branch of industry can do without specially developed elastomers. The main areas of application are where flexible connections, mechanical decoupling and sealing are required.
Sattler-scm has many years of experience and expertise in the development and production of elastomers. Besides sealing rings and bellows, silicone molded parts, rubber buffers and many more are part of our portfolio. If you have any questions about our products, please do not hesitate to contact us by phone or e-mail.
As Managing Director of Sattler GmbH, it is a constant concern of mine to meet our customers not only as a trading partner, but also as a competent procurement service provider for applications in the plastics and rubber sector. I am an engineer by heart and most passionate when I can solve detailed technical issues to create sophisticated, customized solutions.
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