scholarly journals Modeling and Validating Analytic Relations for Electromagnetic Shielding Effectiveness of Fabrics with Conductive Yarns

2021 ◽  
Author(s):  
Ion Razvan Radulescu ◽  
Lilioara Surdu ◽  
Emilia Visileanu ◽  
Cristian Morari ◽  
Marian Costea
Keyword(s):  
Electromagnetic Compatibility ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Tem Cell ◽  
Low Weight ◽  
Conductive Yarns ◽  
Application Requirements ◽  
Analytic Models ◽  
Electromagnetic Shielding Effectiveness

Electromagnetic (EM) radiation may be harmful for human’s health and for functioning of electronic equipment. The field of Electromagnetic Compatibility approaches various solutions to tackle this problem, while shielding of the radiation is one of the main solutions. Since the development of spinning technology for producing conductive yarns for fabrics, textile electromagnetic shields have become a valuable alternative to metallic shields. Their main advantages are given by the flexibility, the low weight and the good mechanical resistance, as well as by the possibility to precisely design the shield. The scientific literature includes several analytic relations for estimating the electromagnetic shielding effectiveness (EMSE), in case of woven fabrics with conductive yarns, which may be modeled as a grid of electric conductors. This book chapter tackles three different analytic models for estimating EMSE, which are useful to predict this functionality in the design phase of fabrics. The analytic relations are subsequently comparatively validated by EMSE measurements via TEM cell equipment of two woven fabrics with conductive yarns out of stainless steel and silver with a grid of 4 mm. Results of validated analytic relations are used for the approach of designing textile shields with regard to final application requirements.

scholarly journals Conductive textile structures and their contribution to electromagnetic shielding effectiveness

2020 ◽  
Vol 71 (05) ◽  
pp. 432-437
Author(s):  
Ion Razvan Radulescu ◽  
Lilioara Surdu ◽  
Bogdana Mitu ◽  
Cristian Morari ◽  
Marian Costea ◽  
...  
Keyword(s):  
Electromagnetic Compatibility ◽  
Modern Technology ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Frequency Range ◽  
Conductive Coatings ◽  
Tem Cell ◽  
Conductive Yarns ◽  
Conductive Textile ◽  
Electromagnetic Shielding Effectiveness

Fabrics for electromagnetic shielding are especially relevant in nowadays context, contributing to human’s protection and wellbeing and to proper functioning of electronic equipment, in relation to electromagnetic compatibility. Fabrics with electromagnetic shielding properties employ two main technologies, namely insertion of conductive yarns and application of conductive coatings. Magnetron sputtering is a modern technology to enable conductive coatings with thickness in the range of nanometers onto fabrics. This paper aims to analyze contribution of various conductive textile structures out of both fabrics with inserted conductive yarns and coatings to Electromagnetic shielding effectiveness (EMSE). EMSE was measured in the frequency range of 0.1–1000 MHz by using a TEM cell according to standard ASTM ES-07. Results show a gain of 10–25 dB when introducing silver yarns in warp/ weft direction, a variation of 5–35 dB between conductive yarns out of silver and stainless steel and an up to 12 dB gain out of thin copper coating by magnetron plasma onto the fabrics with inserted conductive yarns

scholarly journals THE GAIN IN SHIEDLING EFFECTIVENESS ACHIEVED BY SUPERPOSITION OF STAINLES-STEEL PLASMA COATED WOVEN FABRICS

2021 ◽  
Vol 2021 ◽  
pp. 348-354
Author(s):  
I.R. Radulescu ◽  
L. Surdu ◽  
E. Visileanu ◽  
I. Sandulache ◽  
C. Morari ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Plasma Coating ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Frequency Range ◽  
Tem Cell ◽  
Textile Fabrics ◽  
Conductive Yarns ◽  
Cell Measurement

Electromagnetic shielding based on textile fabrics is important in applications for ensuring proper work of electronic equipment and for protection of human’s health. Fibre-based materials include a good capability for a precise design of the physical and electric properties of the EM shields. There are two main methods to impart electroconductive properties to textile fabrics: insertion of conductive yarns into the fabric structure and coating with conductive layers. In our approach, both methods were applied: cotton woven fabrics with conductive yarns of stainless steel and silver, were coated by magnetron sputtering with stainless steel layers. Electromagnetic shielding effectiveness (EMSE) was determined by Transversal-Electric- Magnetic (TEM) cell measurement system, according to standard ASTM ES-07. Moreover, EMSE was determined for the superposition of the manufactured textile shields. The stainless-steel plasma coating improves EMSE with 20 dB in case of the fabrics with stainless steel yarns and with 15-17 dB in case of the fabrics with silver yarns, in the frequency range of 0.1-1000 MHz. By superposition of the plasma coated shields, the gain in EMSE achieved was of 6 dB for the fabrics with stainless steel yarns and of 5-8 dB for the fabrics with silver yarns, on the same frequency range. EMSE has significant higher values in case of the superposed shields with silver yarns and stainless-steel coating for the frequency domain of 100-1000 MHz, due to the higher thickness and the significant contribution of the multiple reflection term.

scholarly journals Electromagnetic Shielding Effectiveness of Woven Fabrics with High Electrical Conductivity: Complete Derivation and Verification of Analytical Model

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1657 ◽  
Author(s):  
Marek Neruda ◽  
Lukas Vojtech
Keyword(s):  
Electrical Conductivity ◽  
Analytical Model ◽  
Electromagnetic Interference ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
High Electrical Conductivity ◽  
Shielding Effectiveness ◽  
Textile Composite ◽  
A Value ◽  
Electromagnetic Shielding Effectiveness

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.

Electromagnetic Shielding Effectiveness and Manufacturing Technique of Metal Complex Fabrics

2014 ◽  
Vol 496-500 ◽  
pp. 472-475
Author(s):  
Ching Wen Lou ◽  
An Pang Chen ◽  
Ting An Lin ◽  
Ya Yuan Chuang ◽  
Jia Horng Lin
Keyword(s):  
Metal Complex ◽  
Life Time ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
Test Results ◽  
Test Frequency ◽  
Shielding Effectiveness ◽  
Conductive Composite ◽  
Composite Yarn ◽  
Electromagnetic Shielding Effectiveness

In the research, The electromagnetic interferences (EMI) have drastically increased and can disrupt and reduce the life time and the efficiency of devices. Therefore, the electromagnetic shielding problem is become the important issue. In the research, Ni wire and Cu wire (Floodlit Enterprise Co., Ltd.) were used to make the Ni conductive composite yarn and Cu conductive composite yarn via an electrical covering machine. And the Cu conductive composite yarn was fabricated to the woven fabrics with the plain weaving. The test results revealed that the EMSE of the W/K/W complex fabrics have stable EMSE than the W/W/W complex fabrics when the laminated at the same direction. The W/90W/W complex woven fabrics were shown the best EMSE of 46.25 dB, which the test frequency is 1800 MHz.

Processing techniques and properties of metal/polyester composite plain material: Electromagnetic shielding effectiveness and far-infrared emissivity

2018 ◽  
Vol 49 (3) ◽  
pp. 365-382 ◽  
Author(s):  
Jia-Horng Lin ◽  
Ting An Lin ◽  
Ting Ru Lin ◽  
Jia-Ci Jhang ◽  
Ching-Wen Lou
Keyword(s):  
Stainless Steel ◽  
Copper Wire ◽  
Steel Wire ◽  
Far Infrared ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
Double Layers ◽  
Infrared Emissivity ◽  
Shielding Effectiveness ◽  
Electromagnetic Shielding Effectiveness

In this study, a composite plain material is composed of woven fabrics containing metal wire with shielding ability and polyester filament that can provide flexibility and far-infrared emissivity. Furthermore, a wrapping process is used to form metal/far-infrared–polyester wrapped yarns, which are then made into metal/far-infrared–polyester woven fabrics. The effects of using stainless steel wire, Cu (copper) wire, or Ni–Cu (nickel-coated copper) wire on the wrapped yarns and woven fabrics are examined in terms of tensile properties, electrical properties, and electromagnetic shielding effectiveness. Moreover, SS+Cu+Ni-Cu woven fabrics have maximum tensile strength, while SS+Ni-Cu woven fabrics have the maximum elongation and SS+Cu+Ni-Cu woven fabrics have the lowest surface resistivity. Stainless steel composite woven fabrics have far-infrared emissivity of 0.89 when they are composed of double layers. electromagnetic shielding effectiveness test results indicate that changing the number of lamination layers and lamination angle has a positive influence on electromagnetic shielding effectiveness of woven fabrics. In particular, SS+Cu+Ni-Cu woven fabrics exhibit electromagnetic shielding effectiveness of −50 dB at a frequency of 2000–3000 MHz when they are laminated with three layers at 90°.

Electromagnetic shielding effectiveness of copper core-woven fabrics

2009 ◽  
Vol 100 (6) ◽  
pp. 512-524 ◽  
Author(s):  
R. Perumalraj ◽  
B. S. Dasaradan ◽  
R. Anbarasu ◽  
P. Arokiaraj ◽  
S. Leo Harish
Keyword(s):  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Electromagnetic Shielding Effectiveness

The effects of the structural parameters of three-dimensional warp interlock woven fabrics with silver-based hybrid yarns on electromagnetic shielding behavior

2019 ◽  
Vol 90 (11-12) ◽  
pp. 1354-1371
Author(s):  
Marzieh Javadi Toghchi ◽  
Carmen Loghin ◽  
Irina Cristian ◽  
Christine Campagne ◽  
Pascal Bruniaux ◽  
...  
Keyword(s):  
Unit Area ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
Woven Fabric ◽  
Shielding Effectiveness ◽  
Conductive Material ◽  
Conductive Yarns ◽  
Multifilament Yarns

The main objective of the present study was to investigate the increase in the electromagnetic shielding effectiveness (EMSE) of a set of five variants of three-dimensional (3D) warp interlock woven fabrics containing silver multifilament yarns arranged in a 3D orthogonal grid. The EMSE enlargement as a factor of increasing the quantity of the conductive material per unit area was investigated. The quantity of the conductive material per unit area in a 3D woven fabric can be enlarged by increasing either the yarn undulation or the number of conductive yarn systems, while the yarn density and yarn fineness are fixed. Thus, the binding depth of the conductive warp was gradually increased for the first four variants in order to increase the yarn undulation. Alternatively, the conductive weft system was doubled for the last variant with the aim of increasing the quantity of the conductive component. It should be noted that changing the weave structure requires less effort and energy while keeping the same threading of warps in the reed compared to altering the warp density. The EMSE was measured in an anechoic chamber and the shielding was satisfactory for all the variants in the frequency range of 1–6 GHz (19–44 dB). The results revealed that increasing only 7% of the waviness degree of the conductive warps led to 17% EMSE improvement due to increasing of the conductive yarns through the thickness of the variants. Moreover, no upward EMSE was detected for the last variant, despite the fact that the conductive weft system was doubled.

scholarly journals The effects of metal type, number of layers, and hybrid yarn placement on the absorption and reflection properties in electromagnetic shielding of woven fabrics

2019 ◽  
Vol 14 ◽  
pp. 155892501986096 ◽  
Author(s):  
Ilkan Özkan ◽  
Abdurrahman Telli
Keyword(s):  
Stainless Steel ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
Woven Fabric ◽  
Power Ratio ◽  
Shielding Effectiveness ◽  
Hybrid Yarn ◽  
Number Of Layers ◽  
Absorbed Power ◽  
Electromagnetic Shielding Effectiveness

In this study, stainless steel, copper, and silver wires were intermingled with two polyamide 6.6 filaments through the commingling technique to produce three-component hybrid yarns. The produced hybrid yarns were used as weft in the structure of plain woven fabric samples. The electromagnetic shielding effectiveness parameters of samples were measured in the frequency range of 0.8–5.2 GHz by the free space technique. The effects of metal hybrid yarn placement, number of fabric layers, metal types, and wave polarization on the electromagnetic shielding effectiveness and absorption and reflection properties of the woven fabrics were analyzed statistically at low and high frequencies separately. As a result, the samples have no shielding property in the warp direction. Metal types show no statistically significant effect on electromagnetic shielding effectiveness. However, fabrics containing stainless steel have a higher absorption power ratio than copper and silver samples. Double-layer samples have higher electromagnetic shielding effectiveness values than single-layer fabrics in both frequency ranges. However, the number of layers does not have a significant effect on the absorbed and reflected power in the range of 0.8–2.6 GHz. There was a significant difference above 2.6 GHz frequency for absorbed power ratio. An increase in the density of hybrid yarns in the fabric structure leads to an increase in the electromagnetic shielding effectiveness values. Two-metal placement has a higher absorbed power than the full and one-metal placements, respectively. The samples which have double layers and including metal wire were in their all wefts reached the maximum electromagnetic shielding effectiveness values for stainless steel (78.70 dB), copper (72.69 dB), and silver composite (57.50 dB) fabrics.

Multi-Functional Metallic/FIR-PET Wrapped Yarn and Woven Fabric: Electromagnetic Shielding Effectiveness, Mechanical and Electrical Properties

2015 ◽  
Vol 749 ◽  
pp. 265-269 ◽  
Author(s):  
Jia Horng Lin ◽  
Ting An Lin ◽  
Chien Teng Hsieh ◽  
Jan Yi Lin ◽  
Ching Wen Lou
Keyword(s):  
Electrical Resistance ◽  
Copper Wire ◽  
Far Infrared ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
Surface Resistivity ◽  
Woven Fabric ◽  
Shielding Effectiveness ◽  
Best Value ◽  
Electromagnetic Shielding Effectiveness

This study uses 0.08mm copper wire and nickel-coated copper wire as the core and 75 D far infrared filament as the wrapped material to manufacture Cu/FIR-PET wrapped yarn, Ni-Cu/FIR-PET wrapped yarn and Ni-Cu/Cu/FIR-PET wrapped yarn. The three optimum metallic/FIR-PET wrapped yarns are then weaving into Cu/FIR-PET woven fabrics, Ni-Cu/FIR-PET woven fabrics and Ni-Cu/Cu/FIR-PET woven fabrics. Tensile property of metallic/FIR-PET wrapped yarns, electrical resistance of metallic/FIR-PET wrapped yarns, surface resistivity of metallic/FIR-PET woven fabrics and electromagnetic shielding effectiveness of metallic/FIR-PET woven fabric are discussed. According to the results, the optimum tenacity and elongation are chosen as 7 turns/ cm, electrical resistance of Ni-Cu/Cu/FIR-PET wrapped presents the best value, Cu/FIR-PET woven fabric has the lowest surface resistivity and Ni-Cu/Cu/FIR-PET woven fabric shows the best EMSE at 37.61 dB when the laminating-layer number is double layer and laminating at 90 ̊. In this study, three kinds of metallic/FIR-PET woven fabrics are successfully manufactured and looking forward to applying on industrial domains.

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