Thermoplastic elastomer（TPE）is a kind of multifunctional material that shows rubber elasticity at room temperature and can be molded at high temperature. It has both the elasticity of rubber and melt fluidity and reusage feature of thermoplastic. It can replace general vulcanized rubber, and can also replace some general resins. It can also be extrusion processed and maintain its rubber elasticity. At present, thermoplastic elastomer mainly includes styrene thermoplastic elastomer (SBC), polyolefin thermoplastic elastomer (TPO), polyurethane thermoplastic elastomer (TPU), copolyester thermoplastic elastomer (TPEE), copolyamide thermoplastic elastomer (TPA), polyvinyl chloride thermoplastic elastomer (PVC) and so on.
The main applications of parallel twin screw in TPE industry:
1) TPE blending modification ; 2)TPV dynamic vulcanization.
TPE blending modification: elastomer, polymer, filler, oil and functional additives are compounded to achieve specific hardness, density, fluidity index and various physical properties, meeting some functional requirements.
TPV generally refers to PP/EPDM dynamic vulcanized elastomer, also known as Thermoplastic Dynamic Vulcanizate. "Dynamic" means the thermoplastic vulcanized rubber process is dynamic vulcanization, namely, the rubber is vulcanized during the melting and blending of rubber and thermoplastics. The rubber is vulcanized and also continuously compounded with thermoplastics. So the vulcanized rubber is distributed as a dispersed phase in the continuous phase of thermoplastics.
Process and granulation method
There are two main technology routes of TPE: pre-mixed material fed into twin screw extruder; multi-feeding into twin screw extruder by loss-in-weight feeders.
Premixing technology for SBS
SBS production consists of several loss-in-weight feeder system.
TPE is mainly granulated in two ways: underwater pelletizing and strands pelletizing.
Producing SBS with Underwater Pelletizing System
Flame-retardant cable TPE with strands pelletizing
There are two main technology routes of TPV: multiple feeding with loss-in-weight feeders;
premixed with kneader