Design and properties of shape memory sports bras for comfortable pressure based on ergonomics

To improve the difficulty in wearing and uncomfortable pressure of the sports bra, shape memory polyurethane filaments (SMPUFs) were used to prepare seamless sports bras in this study. Five fabric samples with different stitch structures and yarn were prepared. Then shape memory sports bras were designed based on the properties of the different fabric samples and female body characteristics. SMPUFs were characterized by differential scanning calorimetry for the thermal properties. Shape memory properties and mechanical properties of the SMPUFs, covered yarn and fabric samples were measured. Besides this, the moisture absorbency, permeability and thermal resistance of fabrics were tested. A pressure test system was set up and the pressure of the sports bras was investigated at different temperatures. The results showed that the transition temperature ( T trans ) of the SMPUF was 27.33°C, which could be triggered by human skin temperature. The best shape fixity ratio of the fabric sample was 82.5% and the shape recovery ratio was 94.4%. The comfortable pressure of the shape memory sports bra at the mean human skin temperature of 34°C was 1.6–5.6 kPa.