By Stephane Morin, Alliance Polymers & Services, LLC
Before TPEs (thermoplastic elastomers), there was thermoset rubber. But there was a need for a better type of product – one that could increase part production (lowering cycle times), offer lower weight, be easily colorable, be soft or rigid, be recyclable, be produced over other materials in a two shot process (overmolding), and contribute to lower part costs.
Enter TPEs in the 1970’s on a mass scale, soon to be followed by other soft elastomers that soon fell under the general category of TPEs – TPOs or thermoplastic olefins, TPVs or thermoplastic vulcanizates, TPUs or thermoplastic polyurethanes and dozens of new grades that were and are simply ‘alloyed’ products comprised of different components.
Then came new and better products for goods such as sporting equipment, automotive seals and hoses, medical goods, appliance parts, window and glazing seals, wire and cable applications and hundreds of other products in dozens of markets. Thanks to TPEs, they not only looked better and could be processed better, but they performed better and offered a variety of textural and finishing options. Depending on the application and the product, they were softer or harder, more resistant to chemicals and oils, more durable, able withstand far higher and lower temperatures, and ultimately would and could last longer.
The advent of TPEs enabled designers, marketers and manufacturers to offer products with much broader options for design, including improved grip with built-in ergonomics, improved sealing, living hinges, noise and/or vibration damping and protection, and reduce scrap, among others. This was combined by improving product development cycle times, speeding up production cycle times, reducing materials usage and generally decreasing production costs. More recently came bonding grades which maximized the potential of overmolding technology. This reduced or eliminated the need for adhesives or other mechanical interlocks to combine different materials, including grades that could be bonded onto many other polymers as well as many metals (and in fact, replaced many metals). With the ability to overmold onto a variety of materials, components now can easily and cost-effectively produced/molded into soft/hard material combination, while all the while ensuring outstanding performance. At the present time, there are numerous classes of TPEs.
Which TPE to Use?
Below are listed the advantages of each class of TPE. Using these guidelines, potential users can quickly and accurately narrow the type of soft elastomer best suited for their application:
• Polyurethanes (TPU)
• Styrenics (TPE-S)
• Copolyesters (COPE)
• Polyamides (PEBA)
• Polyolefin Alloys (TPV)
• Polyolefin Blends (TPO)
The accompanying chart will give potential users an indication where each class is best suitable for applications depending on prince and performance.
(click on chart to enlarge)
For more information on products and services, contact:
Alliance Polymers & Services
30735 Cypress Road, Suite 400
Romulus, MI 48174
Tel: 734-710-6700 Fax: 734-710-6715