TPE is the general name for Thermoplastic Elastomer, also called thermoplastic rubber. TPE is a rubber like material that can be processed with thermoplastic technologies such as injection moulding, 2K moulding or extrusion. Thermoplastic elastomers (TPE) are compounds made from a hard thermoplastic materials like PP, PBT or PA in combination with soft rubber material often incorporating additives e.g. oil and filler.
Around the year 1960 basic thermoplastic materials were getting more and more common. At that time rubber compounds (thermosets) were already popular in automotive market but they were expensive, difficult to produce and hard to recycle.
With new fashion trends (more flashy colours, soft touch etc) there was a growing demand for a soft, cheaper and easy to produce material. This growth developed into the 1970’s when TPE’s started to be produced on a large scale.
Today there is a wide range of different thermoplastic elastomers (TPE) types eg:
- TPE-O - Thermoplastic Olefins (co-continues hard/soft blend)
- TPE-S - Styrenic SBS, SEBS or SEPS Compound
- TPE-V - Vulcanized PP/EPDM Compound
- TPE-E - Copolyester compound
- TPE-U - Thermoplastic Polyurethane
- TPE-A - Thermoplastic Polyamide
In daily business often the “E” is left out so people talk about TPO, TPS, TPV, TPE, TPU and TPA.
TPE-S (styrenic thermoplastic elastomer) schematic microstructure.
All hard/soft TPE combinations have rubber like properties only differentiated by temperature resistance, chemical resistance, flexibility and recovering after being under load (Compression set).
TPE disadvantages compared to conventional thermoset rubbers are the inferior material properties. TPE’s have lower temperature resistance, chemical resistance and worse form recovery (compression set) after being under load.
The Major advantages of thermoplastic elastomers include the easier conversion (and lower energy cost vs Thermosets) via conventional thermoplastics processes eg injection moulding, extrusion, thermoforming, blow moulding et al. TPE’s can also be easily coloured and overmoulded onto various thermoplastics with good adhesion .
TPE’s are produced by many compounders like Enplast and Ravago (Ensoft, Enflex, Sconablend), Kraiburg, Tecknor Apex, AES, Elasto, Softer with brand names like, Dryflex, Sarlink, Monprene, Santoprene, Laprene and Forprene. Also numerous smaller compounders are active in specific regions.
The petrochemical producers are also involved with specific families of TPE : e.g. DSM with Arnitel TPE-E, Celanese with Riteflex (TPE-E), DuPont with Hytrel (TPE-E), Arkema with Pebax (TPA) and Dow with Engage (TPO).
Typical thermoplastic elastomer’s (TPE) applications are:
- Soft touch parts of tools, pencils, tooth brushes, razors
- Automotive window sealings, car mats, air bag covers, instrument panel covers
- Cable coatings
- Sport equipments
- Roofing membranes