Ultrathin Multilayer Textile Structure with Enhanced EMI Shielding and Air-Permeable Properties

Abstract

A textile material’s electromagnetic interference (EMI) shielding effectiveness mainly depends on the material’s electrical conductivity and porosity. Enhancing the conductivity of the material surface can effectively improve the electromagnetic shielding effectiveness. However, the use of highly conductive materials increases production cost, and limits the enhancement of electromagnetic shielding effectiveness. This work aims to improve the EMI shielding effectiveness (EMSE) by using an ultrathin multilayer structure and the air-permeable textile MEFTEX. MEFTEX is a copper-coated non-woven ultrathin fabric. The single-layer MEFTEX SE test results show that the higher its mass per unit area (MEFTEX 30), the better its SE property between 56.14 dB and 62.53 dB in the frequency band 30 MHz–1.5 GHz. Through comparative testing of three groups samples, a higher electromagnetic shielding effect is obtained via multilayer structures due to the increase in thickness and decrease of volume electrical resistivity. Compared to a single layer, the EMI shielding effectiveness of five layers of MEFTEX increases by 44.27–83.8%. Due to its ultrathin and porous structure, and considering the balance from porosity and SE, MEFTEX 10 with three to four layers can still maintain air permeability from 2942 L/m2/s–3658 L/m2/s.

Effect of sol–gel treatment on physical, chemical and mechanical stability of copper-coated conductive fabrics: focus on EMI shielding effectiveness

“…The EMSE was calculated using Eq. (1), where S 21 is the forward transmission coefficient and represents the ratio of power without and with shielding material [24]. Five measurements of each sample were taken at various locations, and the average has been used for further calculations.…”

Polymer Fibers Highly Filled with Styrene Maleic Anhydride-Modified PbWO4 for Improved Wear Comfort of γ-ray-Shielding Articles

“…Instead, it mainly depends on the layers of the fabrics. 52,53 Air permeability of a single layer to four layers gradually decreases from 292, 172, 120 to 66 mm/s. This is because much more complicated channels are developed with increasing layers of fabrics, which suppresses air movement.…”

The electromagnetic shielding effectiveness of the copper plated nonwoven fabric and its’ related comfort properties

“…Because of this frequency of the electromagnetic spectrum is most commonly exposed to daily life and work environment. 24 All samples’ data of electromagnetic shielding effectiveness is from 20.7 to 45.3 dB at 1.5 GHz frequency, those are displaced in Table 3. In addition, the mass of the samples before and after copper plating are also calculated.…”

“…This kind of measurement standard calculates the electromagnetic shielding effect of the fabric samples by the insertion loss method. 24 The test machine is built up with the sample holders and network analyzer produced by Rohde & Schwarz company. The network analyzer is an important part of the machine and is used to get and receive electromagnetic signals.…”