TPE (Thermoplastic Elastomers)
How many designers know exactly what a surface of Shore hardness 55A feels like? Or what a thermal conductivity of 0.18 W/mK means? A major problem designers face in understanding the differences between plastic materials is this abstract terminology. Plastics are named by chemists to classify a molecular structure, rather than reflect functions or uses. ‘Thermoplastic elastomers’, and the common abbreviation, TPE, doesn’t communicate that this is a hugely versatile material, full of possibilities for designers to explore. TPEs are tactile, with a great rubbery grip; they are temperature-resistant, which makes them suitable for all sorts of cooking utensils; they are shock absorbing, which adds a premium robustness to products.
TPEs also fit well into the discussion about materials as a source of new consumer experiences. Contemporary industrial design is dominated by the desire to embed products with experiences that help to create new relationships between products and consumers. I love the OXO range of products, which make TPEs the hero in their range of products based on providing a good grip. These kinds of material experiences can strengthen a brand by enhancing the senses or by telling stories that relate to sustainability, indulgence or any other brand values.
Image: OXO GoodGrips® vegetable peeler
Key features
•Easy to colour match
•A seductive feel
•Excellent grip
•Excellent flexibility
•Shock-absorbing
•Relatively expensive
•UV-resistant
•Recyclable
Sources
Widely available from multiple global suppliers.
Cost
Relatively expensive: £13 ($20) per kg. However, the high cost of the raw materials can be offset by lower production costs.
Sustainability issues
Highly effective production means shorter production cycles, reduced energy consumption and minimal waste. Recyclable.
Production
TPEs can be moulded using standard extruding, blow moulded, thermoformed and injection moulded. For this last method it is particularly relevant to consider two-shot mouldings and insert mouldings as a major use of TPEs. TPEs can be controlled to offer varying grades of hardness, anything from Shore hardness 55A, which is the same degree of hardness as the palm of a hand, to much firmer grades. They can also be used in modifying traditional thermoplastics, to improve impact strength.
TPEs have a wide variety of highly functional uses that range from seals on the inside of caps of drinks bottles and car windows, to packaging and grips on everything from power tools to toothbrushes.
Derivatives
–Monprene®
–Tekbond®
–Telcar®
–Elexar®
–Tekron®
–Hybrar®
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–Versatile –Good feel and grip –Flexible and tough –Shock absorbent –Widely available –Recyclable |
–Relatively high cost of raw material –Less durable than competitive elastomers |