Thermoplastic elastomers (TPE) cover a group of copolymers and polymer blends with both thermoplastic and elastomeric material properties. Both virgin and recycled TPE find application in automotive, building and construction, electronics, sport, etc.
TPE is a generic term for a range of materials that differ in their chemistry, manufacturing methods, and processability: thermoplastic polyurethanes (TPU), styrene block copolymers (TPS), polyolefin elastomers (TPO), cross-linked olefin-based thermoplastic elastomers, i.e. thermoplastic vulcanizates (TPV), copolyesters (TPC), polyamides (TPA) and other special elastomers. In some cases, these materials can be used as an alternative to PVC in terms of cost perspective. In addition, TPE is used in the automotive, construction, electronics, footwear, sport, and medical sectors. Typical examples are various seals for motor vehicles, doors, windows, and pipes, pipe penetrations, mats, vibration damping mounts, shock absorbers, special cables, mobile phone components, shoe soles, etc.
Basically, the applications of recycled TPE are very similar to those of virgin TPE and include various interior and exterior parts for the automotive, construction, sports and leisure, and household sectors: snowmobile chains, roofing materials, car sealing profiles, shoe soles, and a wide range of other applications such as soft-grip surfaces, design elements, backlit switches and surfaces as well as seals, gaskets or damping elements.
Compared with thermoset rubbers, TPE involves purely physical cross-linking, which results in the main characteristics of the TPE: reversible elongation under stretching and return to its original shape after removal of the stress, melting at elevated temperatures, and absence of a significant creep. These properties offer high potential for recycling of TPE since these materials can be molded, extruded, and reused like thermoplastics. The typical elastic properties of TPE can be maintained by the selection of optimized recycling process parameters. Since the heat resistance of TPE is less than that of rubber, the physical properties decrease with an increase in the temperature.
TPE is cost-effective and can be processed using extrusion, injection and blow molding, melt calendering, 3D printing, etc. Certain TPE types enable simple color adjustment and the possibility to manufacture compounds with virgin and recycled polyolefins or selected engineering thermoplastics. Both virgin and recycled TPE are long-lasting and possess high-impact strength, excellent fatigue as well as tear and abrasion resistance along with good electrical properties. Depending on the type of TPE and the desired application, the material properties can be further improved using additives like flame retardants, UV-stabilizers, antistatic and foaming agents, or monomer resins for rheology control.
Mostly, the post-industrial feedstock is used for the manufacture of TPE recyclates. A large part of the post-industrial TPE is based on various waste materials from the production of items for automotive, electronics, and building and construction. The main post-consumer TPE feedstock is retrieved from automotive, like bumper covers. Typically, TPE recyclates are available as a regrind, regranulate, or compound suitable for extrusion or injection molding. These recyclates are offered in different colors.