Functional enhancement of shoe midsole material based on synthetic fiber hybridization

Abstract

Ethylene Vinyl Acetate (EVA) foam with low fabrication cost and good formability has been widely applied to shoe midsole. Considering the fatigue reduction of runner, it is necessary to reduce the shoe weight and the midsole is the most important target. On the other hand, shoe weight reduction can lead the sustainability in shoe industry. In this study, as a way to weight reduction of foam material while maintaining mechanical functions for shoe midsole, fiber compounding to foam material was investigated. It was clarified that fiber composite foam has higher plateau stress and strain energy compared with conventional foam material at any density range. The reason for increasing plateau stress seems to be shared compressive load by composited fiber. Furthermore, it was concluded that aramid fiber was more suitable than carbon fiber for fiber composite foam as shoe midsole. The fiber length observation was indicated that carbon fiber broke during compounding process.