Views: 65 Author: Site Editor Publish Time: 2025-12-10 Origin: Site
TPU foaming material, also known as expanded thermoplastic polyurethane (E - TPU), was developed by BASF in Germany in 2007 using the principle of gas - phase differentiation. Domestic manufacturers can also produce it.
I. Advantages of TPU Foaming Material
TPU foaming material overcomes the disadvantages of TPU raw materials, such as heavy weight, high hardness, and poor shock - absorption performance. It has the following advantages:
1. Lightweight: It is lighter, reducing the burden of wearing.
2. Breathable: It has stronger breathability, keeping the feet dry.
3. High Rebound: It provides good elasticity to assist in sports.
4. Compression Resistance: It has good compression resistance and is not easily deformed.
5. Low - Temperature Resistance: It has excellent low - temperature resistance, adapting to different environments.
6. Environmental - Friendly: It is environmentally friendly and pollution - free.
7. Wear - Resistant: It has strong wear resistance, extending the service life.
8. Yellowing Resistance: It is not easy to turn yellow, maintaining an aesthetic appearance.
II. Current Situation in the Footwear Industry and the Prospect of TPU
China is the world's largest producer and consumer of sports shoes. Currently, the main cushioning foaming materials for sports shoes are EVA and PU foam. Thermoplastic polyurethane (TPU) has excellent wear - resistance, tear - resistance, and anti - slip performance, and has broad development prospects in the footwear industry.
III. Preparation Methods and Environmental Issues
(1) Preparation Methods
• EVA Foaming Material: It is prepared by chemical foaming, involving the cross - linking of polymer chains.
• TPU Foaming Material: It is prepared by reaction foaming, also involving the cross - linking of molecular chains.
(2) Environmental Issues
Polymer foaming materials with cross - linked structures cannot be melt - recycled. Physical landfilling and incineration are likely to cause environmental pollution problems.
IV. Research Results of the Chinese Academy of Sciences
Experts from the Chinese Academy of Sciences selected high - hardness polyester - type TPU resin and used supercritical CO₂ fluid as a foaming agent. Through autoclave foaming technology, they prepared TPU foaming bead materials with a microporous structure and uniform cell distribution. Then, through special molds and equipment, they made molded parts. Tests show that the TPU foamed midsole has the lowest modulus, the highest energy efficiency, and lower dynamic compression set, making running lighter.
V. Application of TPU in Footwear
TPU is used in footwear mainly because of its excellent elasticity and wear - resistance. Footwear products containing TPU are much more comfortable to wear than ordinary footwear products and are widely used in high - end footwear products, especially sports shoes and casual shoes.
