The effects of fabric lamination angle and ply number on electromagnetic shielding effectiveness of weft knitted fabric-reinforced polypropylene composites

2014 ◽  
Vol 21 (1) ◽  
pp. 129-135 ◽  
Author(s):  
Devrim Soyaslan ◽  
Özer Göktepe ◽  
Selçuk Çömlekçi
Keyword(s):  
Composite Materials ◽  
Composite Structures ◽  
Copper Wire ◽  
Industrial Applications ◽  
Electromagnetic Shielding ◽  
Knitted Fabric ◽  
Shielding Effectiveness ◽  
Polypropylene Composites ◽  
Weft Knitted Fabric ◽  
Electromagnetic Shielding Effectiveness

AbstractIn this study, it was aimed to investigate the effects of fabric lamination angle and fabric ply number on electromagnetic shielding effectiveness (EMSE) of weft knitted fabric-reinforced polypropylene composites. Knitted fabric-reinforced composites are composed of aramid yarn, polypropylene yarn, and copper wire. Polypropylene is the matrix phase and the aramid yarn and copper wires are the reinforcement phase of the composite materials. It was achieved to form 1.5 to 3 mm thickness composites. The composites have nearly 20–50 dB electromagnetic shielding values. To form the knitted fabrics, 7G semiautomatic flat knitting machine was used. The composites were formed by a laboratory-type hot press. EMSE of composites were tested by using ASTM D 4935 coaxial test fixture in 27–3000 MHz frequency band. Lamination angle and ply number parameters were examined related to EMSE of structures. For this study, three different structures were knitted and named as plain knit, 1×1 rib knit, and half cardigan knit. To determine the effect of lamination angle of composites on electromagnetic shielding performance, the composites were produced in two different lamination angles as 0°/90°/0°/90° and 0°/45°/0°/45°. To determine the effect of fabric ply number of composites on electromagnetic shielding performance, the composites were produced in two and four plies. It was observed that the fabric ply number and lamination angle does not affect the EMSE of composite materials very much. It was determined that weft knitted reinforced composite structures have appropriate and high EMSE values for electromagnetic applications. This knitted fabric-reinforced polypropylene composites are flexible and suitable for other industrial applications as civil engineering, aerospace, etc.

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°.

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.

Electromagnetic Shielding Effectiveness of Nickel Fiber-Reinforced Cement Composites

2017 ◽  
Vol 898 ◽  
pp. 2065-2070 ◽  
Author(s):  
Wei Lin Yao ◽  
Guo Xuan Xiong ◽  
Ying Yang
Keyword(s):  
Electrical Conductivity ◽  
Composite Materials ◽  
Electromagnetic Shielding ◽  
Coaxial Cable ◽  
Frequency Change ◽  
Cement Composites ◽  
Fiber Reinforced ◽  
Shielding Effectiveness ◽  
Reinforced Cement ◽  
Electromagnetic Shielding Effectiveness

The nickel fiber was added into the cement-based composite materials as a shielding medium. Influences of the three different types and amount of dispersants and weight fraction of nickel fiber on the electrical conductivity and electromagnetic shielding effectiveness of the cement matrix composite were discussed. The conductivity of cement based composite materials and the uniformity distribution of shielding medium were characterized by four-point probe meter and scanning electron microscopy, respectively. Electromagnetic interference shielding effectiveness in the frequency range of 1 MHz to 1500 MHz was characterized by coaxial cable method. The results indicated that the improved dispersion of nickel by incorporation of dispersants might yield the enhancement of the electrical properties of nickel fiber-reinforced cement composites. When the dosage of methyl cellulose reaches 0.4 wt.%, the pre-dispersing nickel fiber enhances the electrical conductivity of the cement-based composite materials significantly. With the increase of fiber volume fraction, the shielding effectiveness and trend of frequency change of the corresponding fiber-reinforced concrete were enhanced. When the content of nickel fiber powder was 9.0 vol.%, the conductivity was 2.65×10-3 s·cm-1, and the average shielding effectiveness of the specimen in 1MHz-1500 MHz was about 21.78 dB, with the maximum shielding effectiveness of 24.48 dB and the minimum shielding effectiveness 19.85 dB.

Manufacturing Technique and Properties Evaluation of Ni-Coated Copper Composite Fabrics

2013 ◽  
Vol 365-366 ◽  
pp. 1173-1176 ◽  
Author(s):  
An Pang Chen ◽  
Po Wen Hwang ◽  
Ching Wen Lin ◽  
Ting An Lin ◽  
Ya Yuan Chuang ◽  
...  
Keyword(s):  
Copper Wire ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
Test Results ◽  
Shielding Effectiveness ◽  
Composite Yarn ◽  
Core Yarn ◽  
Copper Composite ◽  
Composite Fabrics ◽  
Electromagnetic Shielding Effectiveness

The existence of the electromagnetic radiation may lead to diseases, which also includes cancer and cause the repellence of electrical compatibility. The textiles which have electromagnetic shielding effectiveness become more important in modern life. In the research, the PET/ Ni-coated Copper composite yarn were made by the wrapping machine, which the core yarn is Ni-coated Copper wire and the wrapped yarn is PET filament. After that, the composite yarn is fabricated by the automatic sampling loom into woven fabrics and had the tests of mechanical properties and electromagnetic shielding effectiveness. The test results revealed that the EMSE of the PET/Ni-Cu complex woven fabrics is 32.28dB, which the test frequency is 900 MHz, laminated layer number is 3 and the laminated angles are 0°/45°/90°, respectively.

scholarly journals Electromagnetic Shielding Properties of Knitted Fabric Made from Polyamide Threads Coated with Silver

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1281
Author(s):  
Tanja Pušić ◽  
Bosiljka Šaravanja ◽  
Krešimir Malarić
Keyword(s):  
Composite Structures ◽  
Silver Coating ◽  
Cyclic Process ◽  
Knitted Fabric ◽  
Shielding Effectiveness ◽  
Dry Cleaning ◽  
Surface Mass ◽  
Degree Of Protection ◽  
Shielding Properties ◽  
The Stability

This paper investigates a textile material of low surface mass for its protection against electromagnetic radiation (EMR), which is suitable for composite structures of garments, and for technical and interior applications. The shielding effectiveness against EMR of fabric knitted from polyamide threads coated with silver, measured in the frequency range of 0.9 GHz to 2.4 GHz, indicated a high degree of protection. The key contribution of the paper is the evaluation of the stability of the shielding properties against EM radiation after applying apolar and polar solvents, in synergy with the cyclic process parameters of wet and dry cleaning. The results of the study confirmed the decline in the shielding effectiveness after successive cycles of material treatment with dry and wet cleaning. The effect of wet cleaning in relation to dry cleaning is more apparent, which is due to the damage of the silver coating on the polyamide threads in the knitted fabric.

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