Bamboo Charcoal/Quick-Dry/Metallic Elastic Knits: Manufacturing Techniques and Property Evaluations

摘要

Protective clothing with electromagnetic shielding effectiveness (EMSE) is a functional textile, which shields electromagnetic waves to protect the human body from the far infrared rays. Traditional EMSE garments primarily use metallic plates for reflecting electromagnetic interference (EMI). However, they also have disadvantages of a heavy weight, easy corrosion, and high production cost. In this study, three different functional yarns are combined, during which the twist number of metallic wires is changed for a better shielding effect. A crochet machine is used to fabricate functional elastic knits with the metallic composite yarns as the warp- and weft-inlaid yarns. The test results show that double (D) functional elastic knits exhibit EMSE of above 20 dB when the EMI are between 1.0 and 3.0 GHz. In addition, the knit structure can improve breaking tensile strength by 170 % and increases bursting strength by 58 %, but undermines the tear strength by 10 %. Although changing twist number of metallic composite yarns does not affect water absorption rate along the weft direction, it helps increasing elastic recovery rate by 3.1 %, water absorption rate along the warp direction by 106 %, far-infrared emissivity by 2.3 %, water vapor transmission rate by 20 %, and air permeability by 6 %.