Thermoplastic Polyurethanes: New Material Options for High Performance Footwear

Polyurethane elastomers have been widely used for high performance footwear components, particularly soling systems, since the early 1970s. In addition to excellent performance and durability, reaction molded polyurethanes have been chosen for lightness and comfort. Thermoplastic polyurethane (TPU) elastomers, although offer excellent properties and finish, have not enjoyed the success of two component systems in footwear applications. Reasons for this lack of acceptance have included, among others, weight, hardness and cost. Over the last few years, Huntsman Polyurethanes has embarked in an ambitious research program to expand the acceptance of thermoplastic polyurethanes in the footwear industry. This paper describes in detail new materials, concepts and applications. New families of soft TPUs have been developed that deliver excellent physical performance, superior surface definition and part finish, slip resistance and durability. Novel processing methods have enhanced the acceptance of these new materials for high quality footwear. This paper will also cover breakthrough developments in a new family of light-weight materials which offer unconstrained, cutting-edge design versatility and are revolutionizing the high quality footwear market.