Design and development of a testing instrument to assess multi-layer fabrics under cold conditions

Purpose In cold weather conditions, the thermal performance of multi-layered fabrics plays a critical role in maintaining comfort and safety. This study introduces a unique testing apparatus that has been designed and developed to evaluate the thermal characteristics of multi-layer fabrics specifically designed for extreme cold weather conditions. Design/methodology/approach The thermal conductivity measurement instrument employs a dual-plate methodology, incorporating precise procedures to replicate extreme cold conditions (down to −45°C) in the top zone using dry ice, while also establishing a regulated hot zone (bottom zone) that mimics human skin temperature (33°C) through the use of an electric heater and a proportional-integral-derivative (PID) temperature controller. Findings The experimental apparatus revealed consistent temperature fluctuations (±<0.5°C) and good thermal stability in the bottom zone during both short and long-duration testing periods. In the cold zone, the instrument effectively maintained lower temperature fluctuations (±<2°C) during shorter testing periods. However, because of rapid dry ice sublimation, extended testing durations showed larger temperature fluctuations (±˜5°C). Research limitations/implications These findings also demonstrate the limitations of dry ice as a cooling medium for extended periods of testing time. Practical implications This study aims to enhance the functioning of multi-layer fabrics, which are in demand for cold-weather clothing, based on the tested equipment. Originality/value Though several commercial testing devices and research models based on steady-state and non-steady-state (transient) approaches have been developed, there is still a significant gap in accurately simulating cold weather conditions when evaluating cold weather clothing, with the exception of the thermal manikin method.