Definition of Pu: PU polyurethane is a kind of high polymer material, polyurethane is called polyurethanes, which is the general name of macromolecular compounds with repeated carbamate groups in the main chain. It is made of organic diisocyanate or polyisocyanate and dihydroxy or polyhydroxy compound. Classification of Pu: thermosetting and thermoplastic. TPU is the abbreviation of thermoplastic polyurethane. In China, because of the common name, many pipes called Pu, such as PU bobbins and Pu hose, are actually made of TPU, that is, heat shrinkable PU polyurethane.
The main characteristics of TPU are as follows
1. wide hardness range: by changing the ratio of reaction components of TPU, products with different hardness can be obtained. With the increase of hardness, the products still maintain good elasticity and wear resistance.
2. High mechanical strength: TPU products have outstanding bearing capacity, impact resistance and shock absorption performance.
3. Outstanding cold resistance: the glass transition temperature of TPU is relatively low, and it still maintains good elasticity, flexibility and other physical properties at minus 35 ℃.
4. Good processability: TPU can be processed by common processing methods of thermoplastic materials, such as injection molding, extrusion, calendering, etc. At the same time, TPU and some polymer materials can be processed together to obtain polymer alloys with complementary properties.
5. Resistant to oil, water and mould.
6. Good regeneration and utilization
However, as a thermoplastic polyurethane, TPU can be divided into polyester type and polyether type. It has wide hardness range (60ha-85hd), wear resistance, oil resistance, transparency and good elasticity. It is widely used in daily necessities, sporting goods, toys, decorative materials and other fields. Halogen free flame retardant TPU can also replace soft PVC to meet the environmental protection requirements in more and more fields. Using this technology, TPU flame retardant tube is developed and produced. TPU has many brands and uneven quality. When choosing TPU, we should make a detailed evaluation and demonstration, otherwise we can't get the result of high cost performance