The testing and equivalent calculation of electromagnetic shielding effectiveness of metal fiber blended fabrics

Author(s):  
Junfeng Cai ◽  
Zhaolong Xuan ◽  
Hongbo Liu
2017 ◽  
Vol 88 (9) ◽  
pp. 973-986 ◽  
Author(s):  
Ranran Liang ◽  
Wenjuan Cheng ◽  
Hong Xiao ◽  
Meiwu Shi ◽  
Zhanghong Tang ◽  
...  

In order to obtain a simple and accurate calculation method of shielding effectiveness for woven fabric containing metal fiber yarns, a conductive grid structure model composed of two parallel metal yarn periodic arrays was established. The two periodic arrays were cross-arrangement. The calculation formula of shielding effectiveness for the fabric was deduced through the transfer matrix of the electromagnetic field. The theoretical value of shielding effectiveness of the fabric using the theoretical formula and the measured value tested by the shielding chamber method were compared. Both sets of data were analyzed respectively from the metallic yarn periodic spacing, diameter, electric conductivity, electromagnetic wave polarization direction, and the weaving angle. The result shows that a reasonable agreement between the theoretical value and the measured value has been achieved in a frequency range from 4 to 14 GHz. This shows that the theoretical calculation model is simple, highly precise, and is valuable for the design and development of fabric containing metal fiber yarns. It can be used for estimating the electromagnetic shielding effectiveness of the fabric.


2010 ◽  
Vol 97-101 ◽  
pp. 1790-1793
Author(s):  
Jia Horng Lin ◽  
Yu Tien Huang ◽  
Chin Mei Lin ◽  
Yi Chang Yang ◽  
Chien Teng Hsieh ◽  
...  

According to the results, when low melting polyester fiber increased to be 20%, the electromagnetic shielding/ far infrared ray nonwoven obtained the optimum burst strength, maximum breaking force and maximum tear strength, and they were as follows: burst strength was 4.2 kgf/cm2; maximum breaking force was 153.59 N in the cross machine direction and 70.80 N in the machine direction; maximum tear strength was 215.77 N in cross machine direction and 117.07 N in machine direction; and optimum electromagnetic shielding effectiveness (EMSE) was 45 dB.


2018 ◽  
Vol 53 (11) ◽  
pp. 1541-1553
Author(s):  
İsmail Tiyek ◽  
Mustafa Yazıcı ◽  
Mehmet Hakkı Alma ◽  
Şükrü Karataş

In this study, the production of an electromagnetic shielding material by doping reduced graphene oxide was aimed. Graphene oxide was produced from graphite through modified Hummer's method, and reduced graphene oxide was obtained by reducing graphene oxide. The reduced graphene oxide- doped poly(acrylonitrile-co-vinyl acetate) nanofiber mats were spun on the Polypropylene spunbond fabrics by a multi-needle electrospinning device at different lap numbers. Multi-layered surface samples of spunbond/nanofiber mats were obtained via calendaring process after overlapping in different layer numbers. The electromagnetic shielding effectiveness (EMSE) of these samples was measured in the range of 0.03–1.5 GHz according to ASTM D4935 standard. The effects of the numbers of laps and layers on the electromagnetic shielding effectiveness of the mats were also investigated. It was found that electromagnetic shielding effectiveness is greatly affected by changing the numbers of laps and layers. Consequently, the highest electromagnetic shielding effectiveness value of 35.49 dB was obtained from the sample containing two layers of nanofiber mats, each of which consisted 50 laps of nanofibers.


Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1657 ◽  
Author(s):  
Marek Neruda ◽  
Lukas Vojtech

In this paper, electromagnetic shielding effectiveness of woven fabrics with high electrical conductivity is investigated. Electromagnetic interference-shielding woven-textile composite materials were developed from a highly electrically conductive blend of polyester and the coated yarns of Au on a polyamide base. A complete analytical model of the electromagnetic shielding effectiveness of the materials with apertures is derived in detail, including foil, material with one aperture, and material with multiple apertures (fabrics). The derived analytical model is compared for fabrics with measurement of real samples. The key finding of the research is that the presented analytical model expands the shielding theory and is valid for woven fabrics manufactured from mixed and coated yarns with a value of electrical conductivity equal to and/or higher than σ = 244 S/m and an excellent electromagnetic shielding effectiveness value of 25–50 dB at 0.03–1.5 GHz, which makes it a promising candidate for application in electromagnetic interference (EMI) shielding.


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