Material characteristics of TPU film
With its unique molecular structure, TPU film (thermoplastic polyurethane film) exhibits a composite characteristic that combines a variety of excellent properties. It is widely used in the fields of industry, medical care, consumer electronics, etc. Its core characteristics can be summarized into the following categories:
Excellent mechanical properties are the most significant advantage of TPU membranes. It has high strength and high elasticity, and the tensile strength can generally reach 20~50MPa (partial reinforcement models exceed 60MPa), the elongation rate of break can reach 300%~1000%, and the elastic recovery rate exceeds 90% - even if it is stretched to 3 times the original length, it can still quickly return to its original state after release without permanent deformation. This "hard and soft" characteristic comes from the synergistic effect of the hard segment (isocyanate segment) and soft segment (polyol segment) in its molecular chain: the hard segment forms a physical crosslinking point to provide strength support; the soft segment imparts elasticity to the material like a spring, and the ratio of the two can be precisely regulated by adjusting the formula to meet the diversified needs from "high elasticity close to rubber" to "high strength similar to engineering plastics". In addition, the TPU film has excellent tear resistance and wear resistance, with a right-angle tear strength of ≥40kN/m and a wear amount of ≤5mg/1000 times, far exceeding traditional film materials such as PVC and PE.
The wide adaptability of environmental resistance allows it to cope with complex scenarios. In terms of temperature tolerance, the TPU membrane can maintain stable performance in a wide temperature range of -40℃~80℃: the soft section does not crystallize at low temperatures to avoid brittleness and fracture; the hard section does not melt at high temperatures to maintain structural strength. This characteristic makes it not only adapt to the cold outdoor environment in the north, but also withstand the high temperatures in the car cabin. At the same time, its weather resistance is outstanding. After 1000 hours of ultraviolet aging test, the tensile performance attenuation rate is only 10%~15%, which is far lower than 50% of PVC films. It is insensitive to humidity changes. If used for a long time in an environment with a relative humidity of 90%, the performance fluctuations can be controlled within 5%.
Chemical stability and functional diversity expand the application boundaries. The TPU membrane has good tolerance to common media such as water, grease, acid and alkali: if soaked in water for 30 days, the tensile performance will decrease by no more than 8%; there will be no swelling or cracking after contacting engine oil, detergent, etc., while the PVC membrane is prone to swelling when it encounters oil, and the PE membrane will be eroded by organic solvents. Based on this characteristic, its surface can be modified in a variety of ways, such as matte treatment to improve anti-slip properties, coated with antibacterial layers to enhance hygiene performance, and composite hydrophilic coatings to improve breathability, etc., and the original mechanical properties will basically not be affected after modification. In addition, the barrier properties of the TPU film can be adjusted as needed. By changing the density and microporous structure, it can not only make high breathable films (for clothing and medical care) but also produce high airtight films (for inflatable products and waterproof packaging).
Processing convenience and environmental protection advantages are in line with modern industrial trends. TPU film can be made into products of different thicknesses (0.01~2mm) through extrusion, blow molding, casting and other processes, and is easy to perform secondary processing such as thermal bonding, high-frequency welding, cutting and sewing. The joint strength can reach more than 90% of the substrate itself, and the processing efficiency is 30%~50% higher than that of the rubber film. In terms of environmental protection, its production process does not contain toxic plasticizers such as phthalate. It can be recycled and remodeled 100% after being discarded. It only releases CO₂ and H₂O during combustion, and is free of pollutants such as dioxins. It meets the strict environmental standards such as EU RoHS and REACH. It is an ideal choice to replace non-environmental materials such as PVC.
The combination of these characteristics enables TPU films to meet the strict performance requirements of high-end industrial products, and to meet the diverse needs of daily consumption scenarios, becoming one of the fastest growing polymer film materials in recent years.
