Heat-Controllable Man-Made fibers

Abstract

Thermal-retaining properties of clothing materials are indispensable for a comfortable life in the winter season. In general, thermal retention of clothes is enhanced by the amount of stationary air stored in space among the constituent fibers. Specifically, thinning the fibers, crimping the fibers, and increasing the number of fluffs are effective methods to enhance the thermal retention ability. In this chapter, some methods are introduced to make clothes warm more positively. For examples, following attempts are described, e.g., lowering the thermal conductivity of the fiber itself by the introduction of air in it, increasing radiant heat flux using heat generated by the human body, improving the amount of heat storage using solar light, enhancing hygroscopic exothermicity of cloth using moisture generated from the human body by insensible perspiration, and canceling the environmental temperature change to keep the temperature within clothing constant using the heat energy of phase-change materials. The important policies to enhance the thermal retention ability are explained by specific examples of newly developed materials by some companies.