Electrical resistive heating characterization of conductive hybrid staple spun yarns

Development of heating fabrics has a great potential in numerous applications. Heating fabrics can be developed by various approaches each having its own strengths and weaknesses. Incorporating staple fibre spun conductive yarn in the development of lightweight heating pads offers the advantage of obtaining required heating effect while maintaining flexibility, durability and comfort of the developed fabric. This study aimed at developing a conductive hybrid spun yarn composed of polyester and stainless staple fibers and characterizing its thermal behaviour in response to changes in its structural and procedural parameters. The effect of three variables namely yarn twist coefficient, applied voltage and tension on the yarn during testing, was investigated on thermal behavior of the yarn. Among the three, the applied voltage was found to dominantly control the temperature and hence the heating effect of the hybrid yarn. Yarn twist coefficient, which makes the yarn structure of the same fineness more compact at higher twist levels, was found to improve the heating effect at increased twist level at an applied voltage. However, changes in the tension on the yarn during the test was found to be not affecting the yarn temperature, thus producing a steady heating effect under varying tensions. The study shows that other than changing the applied voltage, the heating effect of the yarn can be improved by changing its twist level which controls the compactness of the yarn and thus different products with required thermal behavior can be tailored.