Electromagnetic interference shielding of stitched carbon fiber composites

Abstract

This study reports on the improvements in the electromagnetic interference shielding effectiveness of unidirectional carbon fiber-epoxy composites as a results of stitching with conductive and nonconductive threads. Unidirectional carbon fiber laminates stitched with copper, titanium, Kevlar metallic, Kevlar 10 and Dyneema T90 threads were manufactured using vacuum assisted resin infusion process. Representative samples from each laminate were tested in directions normal and axial to the fiber direction using rectangular waveguide. Experimental results showed that composites with improved shielding effectiveness in both directions were produced. For example, stitching with copper doubled the shielding effectiveness in the axial direction when compared to the unstitched laminate. In addition, composite stitched with Dyneema exhibited the most balanced increase in the shielding effectiveness in both axial and normal directions (91.5% and 17.3%, respectively) compared to the unstitched laminate. The shielding mechanism of the composites was mainly reflection.

Electroless plating process for the manufacture of radiation protection suits for pregnant woman: Effect of bending on its electromagnetic shielding performance

“…It is also indicated electroless plating process can be used to prepare the fabric with electromagnetic shielding properties. [1][2][3][5][6][7][8] In order to analyze the effect of bending on the electromagnetic shielding performance of cotton. The test diagram is shown in Figure 5(a).…”

“…Besides making life easier and more prosperous, it exposes humans to various unexpected dangers. [1][2][3][4][5][6][7][8] The widespread popularity of mobile phones, computers, microwave ovens, and other household appliances has brought convenience to people, while the harm of electromagnetic radiation is also increasingly prominent, electromagnetic radiation protection for pregnant women has become a hot topic of public concern in recent years. [9][10][11][12] Silver-printed terylene is presented to fabricate anti-electromagnetic radiation Maternity Dress (AMD) with superior shielding effectiveness, preventing a high Electromagnetic interference (EMI) shielding effectiveness of 55-75 dB, which can meet the electromagnetic protection requirements of general equipment, such as home appliances, office automation and other equipment.…”

“…It is well known that an EMI shielding material with high shielding effectiveness (SE t ) is a key indicator for AMD, it should also concurrently have the advantages of low density and exceptional flexibility as well. [6][7][8][9]19,23 The metal particles on the substrate surface without activated groups hold incompact structure and easy to break off in the plating solution. 23,24 It is noted that in most reports, the introduction of active group, the adsorption of catalytic centers, and electroless plating (three-step process) are the common technology.…”

“…23,24 It is noted that in most reports, the introduction of active group, the adsorption of catalytic centers, and electroless plating (three-step process) are the common technology. [5][6][7][8][9][10] In contrast, the cotton surface is a rich source of activated group, cotton has higher surface free energy because there are many -NH 2 and hydroxyl groups in the cotton/polyester blend fiber surface. When cotton was sensitized by Sn 2+ , activated by Pd 2+ , and plated by Ni particle in sequence.…”

Fiber Takviyeli Silindirik Kabuğun Ekranlama Etkinliğinin Analizi ve Simülasyonu

“…The aircraft/spacecraft manufacturing industry is one of the areas that reinforced composite materials are widely used as a replacement for metals. The new composite materials like Composite material skin(CMS) (Aziz et al, 2012), Carbon fiber reinforced polymer(CFRP) (Bui et al, 2015;Abdelal, 2018;Munalli et al, 2019), Carbon fiber reinforced composites (CFRC) (De Rosa et al, 2009;Greco et al, 2012) and Graphite-epoxy (GrEp) (Bogorad et al, 2008) are used in aircraft/spacecraft construction. Instead of the physical and chemical advantages of these materials, the electrical conductivity of the composite materials is much lower than those metals (Evans, 1997).…”