A large field of thermoplastic elastomeres and its applications has been developped during recent years.
Performance is similar to rubber materials however they can be processed by thermoplastic process technologies.
A large field of TPE exists regarding chemistry and technical properties, however all of them are based on block-copolymeres, where elastomeric polymere segments polymerize with thermoplastic base segments. Many types of TPE allow for large variations of the amount of thermoplastic and elastomeric segments, so that the elasticity can vary from almost rigid to extremely soft.
Basic TPE families are:
- TPE-U: Soft-Polyurethane; many applications in footware
- TPE-S: Styrol blockcopolymeres
- TPE-E: Thermoplastic polyester elastomeres, Elastomeres with very good mechanical performance and cold flex. Often used for technical applications
- TPE-O: TPE based on oleofins (PP, EPDM)
- TPE-A: (also ⇒ TPA) also "PEBA"=Polyether-Block-Amide. Copolymerisate based on PA6, PA11, PA12. Excellent mechanical performance and cold flex.
Most TPE are non polar and have low surface energy. Prior to glueing, painting or printing they usually need to be treated with chemical primers. A prefered alternative is plasma activation by oxygene process gas. The process includes cleaning and if proceeded for longer time etching of the surface.
A most important field for applications of TPE developped in recent years are Hard-soft-combinations where hard thermoplastic resins are injected onto TPE premoulds or (usually prefered) inverse. If premoulded inserts are used, the adhesion to overinjected materials can be improved by plasma activation of the inserts.