Thermoplastic Elastomer Compounds and Their Industrial Application
When you look into your toolbox, chances are you will find tools with a soft grip that helps in minimising the severity of shock as well as giving you a firm hand grip. Hairbrushes and toothbrushes also have similar grips thereby making them comfortable to hold. Most of these grips are made from thermoplastic elastomer (TPE) compounds. Basically, thermoplastic elastomers refer to a type of thermoplastic polymer which melts when exposed to heat that is above its melting point. Thanks to this property, thermoplastics can be easily recycled and hence used over and over again. There are lots of thermoplastics some of which include polyethylene and polyvinyl chloride. The unique feature with thermoplastic elastomers that make them different from the rest of the thermoplastics is their soft and flexible rubbery feel.
Varieties of Thermoplastic Elastomers
Thermoplastic elastomers contain several polymers strung together to give the material a soft and elastic property as well as make it stronger. For instance, styrenic block copolymer thermoplastic elastomers contain an elastomeric part and styrene, connected in alternating blocks. The common types of thermoplastic elastomers include:
Thermoplastic Olefin TPO – These are made from polypropylene which is blended with EPDM, an elastomer.
Thermoplastic Elastomer Vulcanisate – These compounds are crosslinked or vulcanised giving them resistance to heat deformation and high compression set.
Common Applications for Thermoplastic Elastomers
There are several uses for TPE compounds spanning different industries. The most common ones include:
Soft Touch Applications – Because of their soft rubbery feel, TPE compounds can be extruded or molded into hard thermoplastic materials. These are often used in tool handles to give you a soft, but firm grip. The softness of TPE compounds is measured on the Shore hardness scale by a durometer. The softer the material, the lower the durometer.
Food Applications – Some TPEs have been approved for use in food contact applications. This indicates that these specific TPEs are safe and do not contaminate food items. Some of the items made of TPE compounds include toddler cup spouts and baby spoons.
Medical and Health Care – TPVs & TPEs that meet the appropriate regulatory standards in Australia are sterilised using ethylene oxide, autoclaves or gamma irradiation. They can substitute rubber, PVC, silicone, or latex.
Sealing Applications – Traditionally, sealing rings have been made from thermoset rubbers. However, with the coming of TPE compounds, thermoset rubbers have been substituted by TPE sealing rings which have risen in popularity. The advantage with TPEs is that they can be easily co-molded to give two component seals. Therefore, TPE compounds are much more versatile and you should consider using them in your next manufacturing application.