Thermoplastic polyurethane (TPU) is a type of polyurethane that can be heated, plasticized and solvent-dissolved. Compared with mixing type and casting type polyurethane, there is no or little chemical crosslinking on the chemical structure, and its molecules are basically linear, but there is a certain amount of physical exchange. Therefore, this type of polyurethane is called thermoplastic. Polyurethane.

In 1958, Schollenberge C.S. first proposed the theory of physical exchange (essentially cross-linking). The so-called physical exchange means that there is a "connection point" between the molecular chains of the linear polyurethane that is reversible when exposed to heat or solvent. It is not actually a chemical crosslink, but acts as a chemical crosslink. Due to the effect of this physical cross-linking, the polyurethane forms the theory of heterogeneous morphological structure, and the hydrogen bonding of the polyurethane strengthens its morphology and makes it resistant to higher humidity; it is precisely due to the physical cross-linking theory, In addition to casting and mixing, another type of polyurethane, thermoplastic polyurethane, has appeared on the market.

Like casting polyurethane (liquid) and mixing polyurethane (solid), TPU elastic belt has high modulus, high strength, high elongation and high elasticity, excellent wear resistance, oil resistance, low temperature resistance, aging resistance .