Electromagnetic Shielding Properties of Plain Knitted Fabrics Containing Conductive Yarns

Abstract

In this study, stainless steel conductive yarns with 500 tex fineness and 14 Ω/m linear resistances were inserted into the reverse side of the knitted fabrics made from acrylic yarns. Six types of knitted fabrics with conductive yarns were produced on an E=7 gauge electronic flat bed knitting machine. Then the electromagnetic shielding efficiency (EMSE) of the sample fabrics were measured in the frequency range of 750 MHz – 3000 MHz. The EMSE variations of the sample fabrics having conductive yarns with respect to fabric structure and polarization type (vertical and horizontal) were also investigated. It was observed that the same samples showed different behaviors and have dissimilar EMSE values in different polarization conditions. When compared to horizontal polarization measurements, the vertical measurement results gave better EMSE values.

Realization of planar frequency selective fabrics and analysis of transmission characteristics

“…Traditionally, EM shielding fabrics are fabricated through a conductive polymer coating on the surface of existing fabrics, 6,7 or through conductive yarn weaving, 8,9 making the entire products continuously conductive and analogous to compact plates. However, the advantages of textiles in use depend on their properties of light weight, softness, and flexibility, especially for textile garments.…”

Ultra-lightweight hybrid woven fabric containing stainless steel/polyester composite yarn for total EMI shielding in frequency range 8–18 GHz

“…[32] Knitted fabric with acrylic yarn and SS yarn of 500 tex fineness and 14 Ω/m linear resistance offered attenuation up to −15 dB in 750-300 MHz frequency. [33] Twill weave fabric of 200 gsm containing hybrid/composites yarn (30% SS/70% PET) showed shielding of 35-40 dB in 300 kHz-3 GHz. Woven fabrics with yarn density of 54 × 21, using conducting hybrid yarn with SS fibre and polyester fibre in both directions, has shown maximum EMSE at 180 MHz.…”

Investigation of electromagnetic shielding effectiveness of needle punched nonwoven fabric produced from conductive silver coated staple polyamide fibre

“…Problems may range from headache to fatigue, dizziness and memory loss to miscarriage, leukaemia and cancer (Ceken, Pamuk, Kayacan, Ozkurt, & Ugurlu, 2012). Prolonged exposure to EMFs has been shown to cause physiological change in human tissues, and according to some researchers is linked to cancer, leukaemia, neurodegenerative disorders and all manner of diseases (Bhattacharjee, 2014).…”