The Research on Wood Fiber/Stainless Steel Net Electromagnetic Shielding Composite Board

2012 ◽  
Vol 525-526 ◽  
pp. 437-440
Author(s):  
Chu Wang Su ◽  
Quan Ping Yuan ◽  
Wei Xing Gan ◽  
Jing Da Huang ◽  
Yuan Yi Huang

In this paper, the electromagnetic shielding function composite fiberboards were made by filling with stainless steel nets dipped with urea-formaldehyde resin adhesive (UF) and the influence of different mesh and layers of nets on its electromagnetic shielding performance, static bending strength (MOR), modulus of elasticity (MOE) and internal bonding strength (IB) were studied. The results showed that: when the mechanical strength was enough and the frequency was in range of 50MHz to 1GHz, of all the composite fiberboards filled with one-layer stainless steel net, the one filled with 60 mesh was best and the minimum shielding effectiveness (SE) was 36.22 dB; when filled with two-layers nets, the one filled with 80 mesh was best and the minimum SE was 42.54dB; when filled with three-layers nets, the one filled with 60 mesh was best and the minimum SE was 50.77dB.

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 5291-5304
Author(s):  
Se-Hwi Park ◽  
Min Lee ◽  
Pureun-Narae Seo ◽  
Eun-Chang Kang ◽  
Chun-Won Kang

The demand for noise control in residential environments is steadily increasing, but the currently available noise-reducing materials used in walls and floors are unsustainable and expensive. As an alternative, wood-fiber could be a good resource to manufacture eco-friendly acoustic materials. In this study, fiberboards were prepared by mixing wood-fibers (Pinus densiflora) with melamine-urea-formaldehyde resin adhesive, obtaining specimens with different final densities and resin contents. The acoustic, physical, and morphological properties of the fiberboards were investigated. The sound absorption was greatly influenced by the density of the fiberboard: lower densities showed higher sound absorption performances. Furthermore, the low-frequency absorption coefficient was higher for lower resin contents. The materials met all the criteria required by the Korean standards for fiberboards. As the density increased, the dimensional stability and the bending strength increased; in contrast, the physical properties were not affected by the resin content. Microscopy observations confirmed that specimens with different densities and resin contents had different porosities; the porosity was assumed to be the main property that governs the noise-reducing ability. Due to their eco-friendliness and inexpensiveness, these fiberboards offer themselves as efficient and effective alternative sound-absorbing materials.


2012 ◽  
Vol 518-523 ◽  
pp. 3349-3357 ◽  
Author(s):  
Chang Yan Xu ◽  
Jie Liu ◽  
Xu Dong Zhu

Just like other paper/plastic/aluminum (PPA) composites, Tetra Pak-package-material (Tetra Paks) has excellent water and vapor barrier abilities, and is widely used in food and beverage packaging industry. However, serious environmental problem follows due to its long service life. In this paper, a novel electromagnetic shielding composite board was developed with recycled Tetra Paks and copper-iron mixed fibers. The influence of Cu/Fe ratio and mat configuration on board shielding effectiveness (SE), volume resistivity (VR) and mechanical properties were investigated. The results showed that the boards with copper-iron mixed fiber layers showed better electromagnetic shielding performance than those with only iron or copper fiber layer. The SE of the boards was improved with higher copper fiber content. The location of the metal fiber layers in the mat had a significant influence on board electromagnetic shielding performance. A symmetrical sandwich structure was found beneficial to better shielding performance, and in the same condition of wave frequency and shielding material thickness, the shielding system with a Fe core exhibited better shielding performance than that with a Cu core. The ratio of Cu/Fe and the configuration of mat both had significant influences on mechanical properties of the boards. It can be concluded that qualified electromagnetic shielding composite board could be produced with Tetra Paks wastes and copper-iron mixed fibers. Showing both environmental and economic values, this type of board could be considered as an alternative material used in packaging, interior finish, furniture, and other applications.


2018 ◽  
Vol 49 (3) ◽  
pp. 365-382 ◽  
Author(s):  
Jia-Horng Lin ◽  
Ting An Lin ◽  
Ting Ru Lin ◽  
Jia-Ci Jhang ◽  
Ching-Wen Lou

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°.


2019 ◽  
Vol 14 ◽  
pp. 155892501986096 ◽  
Author(s):  
Ilkan Özkan ◽  
Abdurrahman Telli

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.


2014 ◽  
Vol 910 ◽  
pp. 262-265
Author(s):  
Jia Horng Lin ◽  
Zhi Cai Yu ◽  
Jian Fei Zhang ◽  
Ching Wen Lou

In order to fabricate fabrics with electromagnetic shielding effectiveness (EMSE) and other function, we fabricated Crisscross-section polyester /antibacterial nylon / stainless steel wires (CSP/AN/SSW) composite yarns with stainless wires as core yarn, antibacterial nylon and crisscross-section polyester as inner and out wrapped yarns, respectively. Knitted fabrics were fabricated with the metal composite yarns with wrap amount of 8 turns/cm on a circular knitted machine. Furthermore, the EMSE of the metal composite fabrics were evaluated by changing the lamination amounts and lamination angles. The results show that when the lamination amount was four, lamination angles were 0°/45°/90°/-45°, the EMSE of the fabrics reached to-10--20 dB in the frequency range of 300 KHz to 3 GHz.


2019 ◽  
Vol 50 (6) ◽  
pp. 830-846
Author(s):  
Yalan Yang ◽  
Jianping Wang ◽  
Zhe Liu ◽  
Zhujun Wang

Electromagnetic radiation is becoming increasingly serious around our living environment, which seriously endangers people's health and interferes with the operation of electronic equipment. The research and development of anti-electromagnetic radiation fabric have drawn more and more attention. However, the influencing rules and mechanisms of conductive fiber content, fabric tightness, warp–weft density, conductive yarn arrangement, weave type, and electromagnetic wave frequency on fabric electromagnetic shielding effectiveness have not been clarified. Therefore, in this study, a series of fabrics containing stainless steel fibers were produced. Meanwhile, the influencing rules of various factors on electromagnetic shielding effectiveness and the quantitative relationship between some factors and electromagnetic shielding effectiveness were discussed. The results showed that all factors had different degrees of influence on electromagnetic shielding effectiveness, and the relationship between electromagnetic shielding effectiveness and electromagnetic wave frequency could be approximately expressed as: [Formula: see text]. At the same time, the influencing mechanisms of various factors on electromagnetic shielding effectiveness were analyzed in combination with fabric microstructure and macrostructure, the intrinsic parameters of the fabric and the electromagnetic shielding effectiveness mechanism. The results are expected to provide a reference for the establishment of electromagnetic shielding fabric model and enterprise production.


2019 ◽  
Vol 70 (3) ◽  
pp. 221-228
Author(s):  
Abdullah Istek ◽  
Ismail Ozlusoylu

In this study, the effect of mat moisture content on the physical and mechanical properties of particleboard was investigated. The experimental boards were produced by using 40 % softwood, 45 % hardwood chips, and 15 % sawdust. The formaldehyde resin/adhesive was used in three-layers (bottom-top layer 12 %, core layer 8 %). Multi-opening press was used during manufacturing the experimental particleboards. The physical and mechanical properties of boards obtained were identified according to the TS-EN standards. The optimum core layer moisture content was determined as 6 % and 7 % according to the results, whereas the moisture content of bottom and top layers was 14 %. Under these moisture content conditions, the bending strength was found to be 13.3 N/mm², the modulus of elasticity in bending 2466 N/mm², and internal bonding strength 0.44 N/mm². The optimum bottom-top layer moisture content was determined to be between 13 % and 15 % and 6.5 % for the core layer.


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