New energy vehicle cables are divided into in-car cables and charging pile cables. Because new energy vehicles have high voltage and current inside and limited space, charging pile cables are exposed to outdoors for a long time, and the special use environment requires strict performance requirements for cable materials. New energy vehicle cable materials need to have properties such as high and low temperature resistance, oil and water resistance, flame retardancy, tear resistance, insulation, and UV resistance. Commonly used materials include TPE, TPU, XLPO, NBR+PVC, chloroprene rubber, and silicone rubber. Why can TPU materials be used in the field of new energy vehicle cables? Today, let's take a look!
TPU, the full name of which is Thermoplastic Polyurethanes, is a thermoplastic polyurethane rubber that combines the hard chain segment of urethane that reacts with isocyanate and the soft chain segment of polyester or polyether. Its chemical structure is basically linear with little or no cross-linking, but it has a certain degree of physical cross-linking, mainly divided into polyester and polyether types.
TPU is a material containing the—NH—COO—group in the molecule. The long-chain diol and isocyanate components form the soft segment, while the short-chain diol and isocyanate components form the hard segment. Many characteristics of TPU plastics depend on the type of long-chain diol, and its hardness is adjusted by the proportion of the hard segment.
The special structure of alternating hard and soft segments gives TPU elasticity and good mechanical properties, as well as its special property of thermoplastic processing.
Compared with other thermoplastic elastomers, TPU has the following advantages:
Excellent wear resistance: Its Taber abrasion value is 0.35-0.5mg, which is the smallest among plastics;
Tensile strength and elongation: The tensile strength of TPU is 2-3 times that of natural rubber and synthetic rubber;
Oil resistance: TPU has excellent oil resistance compared with nitrile rubber and has excellent oil resistance.
Cold resistance, weather resistance, and ozone resistance. The weather aging resistance of TPU materials is better than that of natural rubber and other synthetic rubbers. Its characteristics of ozone resistance and radiation resistance have special uses in the aerospace industry;
Food and medical hygiene: TPU has biocompatibility and anti-coagulation properties, and medical TPU is increasingly widely used, such as blood vessels, ureters, and infusion tubes. At the same time, TPU is free of reinforcing agents, non-toxic and tasteless, and is also widely used in the food industry;
Hardness range: The hardness of TPU is 60A-95A. When the hardness is above 85A, it still maintains elasticity, which is a characteristic that other elastomers do not have, so TPU has high load-bearing capacity and good suction and drainage effects.
Because of the excellent performance of TPU material, its range of use is very wide, and it can be used in sports equipment, medical equipment, industrial parts, footwear supplies, wires and cables, automotive parts, and other fields.
The charging pile cable polyurethane (TPU) sheath material is mainly composed of TPU, supplemented by environmentally friendly or halogen-free flame retardants, antioxidants, and other additives. It has characteristics such as flexibility, pressure resistance, voltage resistance, high temperature resistance, aging resistance, acid and alkali resistance, salt spray resistance, and water resistance.
Polyurethane materials are mentioned in future European electric vehicle standards and other standards and are used in charging piles for high-end electric vehicles in Europe and America.