Fabrication and thermal assessment of three-layer woven heating fabrics

Abstract

Due to the particular physiological conditions of the human body, activity in cold weather condition is of great importance and needs unique thermal clothing. In this research, three-layered heating fabrics were designed and woven to analyze their performance in cold climates. The samples consist of three types of heating elements (nickel-chrome, tungsten, and aluminum-chrome) and two different states for embedding the heating elements in the fabric structure. In order to investigate the effect of voltage on the heat flux and maximum temperature, all specimens were subjected to two voltage levels of 9 and 12 V for 10 min, the process of heat production, the influence of structural factors on the flux and temperature and also the thermal efficiency was analyzed. In addition, in order to select the optimum sample, the amount of required energy for maintaining body comfort was calculated based on the theoretical equations at the ambient temperatures of −5 and −10°C. The results showed that the woven sample using tungsten elements and the weft-to-element ratio of 12 had the desirable heating performance and could maintain the skin surface temperature around the thermal comfort zone.