Analyzing Garment Aperture Effect on Thermal Shrinkage of Flame Resistant Fabrics under Fire Exposure

Thermal shrinkage of flame resistant fabrics can greatly affect the thermal protection of firefighters’ clothing. In this study, four boundary conditions were designed to simulate garment aperture structures. Thermal shrinkage was measured with and without an air gap under three heat-flux levels. The shrinkage ratio was measured and calculated using digital image technology. Results showed that an air gap between the fabric and sensors was the main factor in thermal shrinkage. The presence of an air gap aggravates thermal shrinkage at the garment apertures, especially under the open boundary condition with incomplete fixation. The ease required for human movement and thermal shrinkage should be taken into consideration when designing thermal protective clothing. This study provides a quantitative method for determining the thermal shrinkage of fabrics.