The electromagnetic shielding of textured steel yarn based woven fabrics used for clothing

摘要

The electromagnetic shielding effectiveness (EMSE) of herringbone, whipcord, barathea, and crepe woven fabrics, which are twill and sateen derivatives, woven with textured steel yarns has not been investigated so far. Therefore, in this research, textured stainless steel yarn, which has soft feeling and flexibility, required properties for clothing fabrics, was selected as a conductive yarn to produce conductive fabrics whose weaves are twill, twill and sateen derivatives. The EMSE of these common clothing fabrics woven with different conductive yarn densities were measured by free space measurement technique with different antenna polarizations, because of the possibility to obtain measurements for a large bandwidth. It was observed that all conductive clothing woven fabric samples shielded well in medium and high frequency bands, which contain 900MHz GSM, 1800MHz GSM, 2100MHz3G, and 2400MHz Wi-Fi bands. Most of the samples give acceptable EMSE values up to 40 dB at certain frequencies. The EMSE of fabric samples would remain almost the same, although conductive yarn density changed, because of diagonally or symmetrically arranged conductive yarn floats in fabric structures. The EMSE characteristics of different weave types are investigated and it is seen that when the yarn floats arrangement is changed the EMSE characteristic changes. And also, it is observed that measurements of fabrics, positioned so that the weft yarns were parallel to the antenna polarization are similar to those of fabrics, positioned so that the weft yarns were vertical to the antenna polarization.