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THERMOPLASTIC ELASTOMERS (TPE) INTRODUCTION |
| V. Ryan © 2011 |
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| They are a combination of thermoplastics and elastomers. Although classed as polymers, they act like a thermoset rubber. In simple terms, they are a mix of polymers and rubber giving them a combination of the physical properties, attributed to thermoplastics and rubber (elastomers). This can include combining flexibility (rubber) with toughness (thermoplastics). TPEs can be processed using the same techniques associated with thermoplastics, including injection moulding and blow moulding. |
| TPE manufacturers combine a mixture of polymers and elastomers, depending on the needs of their customers. The mixture reflects the properties required by the products manufactured by their clients. For example, a company manufacturing the ‘plastic’ casing for TV revote controls will need a combination of mechanical properties including; toughness, high wear resistance and a certain amount of elasticity. The TPE will be manufactured to meet these properties. |
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| GENERAL PROPERTIES |
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They have good tensile strength and are tear resistance. They resist chemicals and ink / paint adhere well to them. They have good properties of flexibility and resistance to compression. After bending, they will return close to their original shape / form. They can be reprocessed / recycled by raising the temperature above melting point. They can be reformed during the melting process, unlike many other forms of plastics. They can be extruded, blow moulded and injection moulded. They can be remoulded if the temperature is raised until the TPE becomes soft and pliable. |
| MAIN DISADVANTAGES |
| The main disadvantage of TPEs is their high cost compared to other plastics. If they are heated to a relatively high temperature, they tend to lose their ‘rubbery’ property. TPEs tend to ‘creep’. This is a tendency to move and deform when under the influence of stress, such as sustained pressure and temperature. |
| GENERAL USES |
| They are used widely in the automotive industry, replacing common elastomers (rubber) because of their ability to resist wear and tear. They are also used in the casing of electronic devices such as TV remote controls. They resist damage when dropped or knocked. |
| EXAMPLE TPEs |
| Arnitel, Hytrel, Kraton, Riteflex and Styroflex |
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