Enhancing the thermal comfort of fabrics for the footwear industry

A nonwoven fabric, three foams and leather, commonly used as fabrics for shoe manufacturing, were doped with microcapsules containing phase change materials (PCMs) and also with carbon nanofibers (CNFs) in order to improve the thermal comfort provided by the shoes. The maximum microcapsule content that can be incorporated and the influence on the weight, thickness and the thermal properties and behavior of the fabrics were evaluated. The resulting materials showed a thermal energy storage (TES) capacity up to 13.74 J/g and a maximum thickness increase of the composite fabric of 0.6 mm. The PCMs addition promoted a slight modification of the steady-state temperatures of the fabrics subjected to heating or cooling processes and the stored and released heats confirmed that PCMs work in a reversible way. On the other hand, the addition of CNFs compensated for the insulating effect of the PCMs. Finally, it was found that footwear containing these materials could hold the foot temperature for a longer time than parent fabrics.