TPU Injection Shoe Material
TPU is an elastic material between rubber and plastic.
A) What is TPU?
TPU is a common high-quality and versatile material, which stands for Thermoplastic Urethane. It has strong tensile and elongation properties, as well as excellent toughness and resistance to aging. As an elastomer between rubber and plastic, its greatest characteristic is its hardness and elasticity, which other rubbers and plastics do not possess.
B) What are the characteristics of TPU?
1. Wide range of hardness
By adjusting the proportions of various reactive components in TPU, products with different hardness can be obtained. With changes in hardness, the products still maintain good elasticity and abrasion resistance. TPU can be applied to shoe soles to adjust to different ground conditions, providing different hardness and tread designs to meet different wearing needs.
2. High mechanical strength
TPU shows excellent tensile strength, tear strength, hardness, and elasticity, resulting in outstanding impact resistance and shock absorption performance for TPU products.
3. Excellent temperature resistance
TPU generally has good temperature resistance. It can be continuously used at temperatures of 80-90°C, and can reach temperatures of around 120°C for short periods of time. It also has good low temperature resistance, maintaining good elasticity, flexibility, and other physical properties at -35°C.
4. Good processing performance
TPU can be processed using conventional thermoplastic processing methods such as injection molding, extrusion, calendering, blow molding, and compression molding. TPU can also be processed together with certain polymer materials to obtain polymer alloys with complementary properties. Lanxuan mainly processes shoe materials using three methods: injection molding (outsole and midsole), blow molding (air cushion and inflatable sole), and compression molding.
5. Oil resistance, water resistance, and mold resistance
These features make TPU shoe materials durable, corrosion-resistant, and odorless, among many other advantages.
C) The application of TPU on the sole of the shoe.
The application of TPU on the sole of the shoe mainly consists of three components: upper, midsole, and outsole.
1. Upper - TPU yarn and TPU synthetic leather
Breathable knitted upper and waterproof leather upper are common materials for sports shoe uppers. Knitting the entire upper as one piece, known as "Flyknit," can be done using TPU yarn, which is soft, durable, and highly wear-resistant. It can also be easily molded through heat pressing and 3D shaping. In addition to knitted uppers, TPU can also be used to make synthetic leather for uppers and decorative pieces. Our company also offers injection-molded decorative pieces for uppers.
2. Midsole: ETPU
Midsole is the most popular and mature application of TPU in sports shoes. The common process is to foam TPU into particles using a supercritical kettle foaming process, and then combine it with water vapor or microwave forming to obtain ETPU midsoles. Compared to traditional EVA midsoles, E-TPU materials have excellent resilience, extremely low compression permanent deformation, and a comfortable wearing experience. In addition, TPU insoles can also be prepared using foaming process, with the foam material first being formed into sheets and then cut.
3. Outsole: Wear-resistant, anti-slip TPU
TPU can be molded into outsoles through injection molding, with features such as high wear resistance and strength. Lanxuan company can meet various requirements in terms of wear resistance and anti-slip properties through ingredient adjustment and process selection, providing customers with cost-effective products.
