Development of moisture-responsive fabrics and ventilated garments in high-temperature field environments

Abstract This study aimed to develop a moisture-responsive fabric system that can regulate ventilation without external power and to evaluate its ability to improve thermal comfort when applied to a ventilated garment (VG). Six composite fabrics were fabricated by laminating hydrophilic woven and knitted base materials with a hydrophobic polyurethane nanoweb (PUN). Physical characterization showed that increasing the number of PUN layers gradually increased the fabric thickness and weight, while microscopic observation confirmed that the nanowebs formed stable and continuous layers on the fabric surface. Among these, CK/PUN3 exhibited the highest moisture responsiveness, which was associated with the different moisture responses between the hydrophilic substrate and hydrophobic nanoweb, as well as the porous and flexible knitted structure. The selected fabric was incorporated into a hoodie-style VG with 10 flap-shaped inserts, including three on the front torso and seven on the upper back, while mesh fabrics were added to the hood and underarms to improve airflow. The garment, designed from a stretchable polyester/polyurethane fabric, was visualized in CLO 3D and physically prototyped. A sweating thermal manikin test under controlled climate conditions (35 ± 0.5 ℃, 40 ± 5% RH) demonstrated that the VG reduced intrinsic and total evaporative resistance by 7.50% and 2.17%, respectively, compared to the control garment. Regional heat flux increased by 26.78% in the abdomen, 18.59% in the chest, 7.68% in the head, and 4.14% in the back. These findings suggest that passive moisture-responsive garments can improve localized heat release and thermal comfort in high-temperature outdoor environments.