A kind of midsole material and forming method thereof of ultra-light and high-rebound etpu composite shock-absorbing shoes

Abstract

The invention discloses an ultra-light and high-rebound ETPU composite shock-absorbing shoe midsole material and a molding method thereof. The ultra-light and high-rebound ETPU composite shock-absorbing shoe midsole material is made of a TPU composite material through granulation, foaming and molding processes. Prepared; TPU composite material includes, in parts by mass: 60-95 parts of TPU resin, 0-20 parts of nylon elastomer resin, 0-20 parts of polyester elastomer resin, 1-5 parts of polyester resin, and 0.5 parts of nucleating agent -2 parts, antioxidant 0.1-0.5 parts, stearic acid 0.1-1 part and cell stabilizer 0.1-0.5 parts; among them, TPU resin is composed of TPU resin with hardness Shore 90-95A and hardness Shore 50 A mixture composed of ‑60A TPU resin, the TPU resin with a hardness of 90‑95A accounts for 80%‑95%, and the TPU resin with a hardness of 50‑60A accounts for 5%‑20%. The composite shock-absorbing shoe midsole material produced has a relatively light weight, high hardness, high rebound, low compression deformation and high tensile strength, which can greatly reduce the weight of sports shoes. , also has the functions of long-lasting comfort and long-lasting shock absorption, giving the wearer a better wearing and running experience.

Description

technical field [0001] The invention relates to the technical field of shoe manufacture, in particular to an ultra-light and high-rebound ETPU composite shock-absorbing shoe midsole material and a forming method thereof. Background technique [0002] In the field of sports shoes, lighter shoes have an important impact on athletes' sports performance and wearing experience. Lightweight materials have always been the unswerving pursuit of terminal brands. The ultra-light ethylene-vinyl acetate copolymer (EVA) foam material has a density of 0.08-0.16g / cm3 and a Shore hardness of C40-55, which can meet the design requirements of ultra-light sports shoes. However, the ultra-light EVA foam shoe material has the problems of poor rebound and large permanent deformation, which makes it difficult to meet the performance requirements of high-quality sports shoes. [0003] Thermoplastic polyurethane resin (TPU) is a copolymer composed of hard segment and soft segment materials, which h...

AI Technical Summary

Problems solved by technology

[0004] Traditional ETPU shoe products are usually made by physical foaming process. The common hardness of TPU is 80-85A. Due to the introduction of a large number of cell structures into the TPU matrix by physical foaming, the material becomes TPU. The resin / bubble composite composed of resin skeleton reduces the density of the material, resulting in a decrease in the hardness of the foamed material. According to industry test data, when the hardness of TPU resin is 80-85A, the density is 0.2g / cm 3 The Shore hardness of ETPU products is only 38-42C, and the density is 0.15g / cm 3 The Shore hardness of ETPU products is only 32-38C, and the density is 0.1g / cm 3 The Shore hardness of ETPU products is only 28-32C; this is for a density of 0.08-0.15g / cm 3 For the midsole of ultra-light foamed shoe materials, it is difficult to meet the requirements of the appropriate hardness (Shao C40-55) of the material when only using high-hardness TPU and the ETPU prepared by combining the existing foaming process. The greater the hardness of ETPU, the greater its density; the smaller the hardness, the smaller its density. In order to improve the hardness of ETPU, it is usually necessary to add high-hardness TPU with a larger mass. In this case, if you want To obtain a lower density ETPU finished product, it should be achieved by controlling the foaming conditions, that is, increasing the foaming pressure and foaming temperature, and the increase in foaming pressure and foaming temperature will make the TPU molecules strong polarity The physical cross-linking points between the groups are reduced, resulting in severe shrinkage of the expanded beads, which will reduce the resilience and tensile strength of the produced ETPU, and its compression set will be large, which greatly affects the processing and processing of the finished ETPU product. Performance

It can be seen that the foaming pressure and foaming temperature should not be too high when only high-hardness TPU is used to obtain low-density, high-hardness ETPU finished products. not ideal

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