Study on properties of electromagnetic shielding yarns and fabrics

2020 ◽  
Vol 32 (5) ◽  
pp. 677-690
Author(s):  
Xinjin Liu ◽  
Xinxin Yan ◽  
Xuzhong Su ◽  
Juan Song

PurposeWith the popularization of electronic products, the electromagnetic radiation pollution has been the fourth largest pollution after water, air and noise pollution. Therefore, electromagnetic shielding property of textiles is attracting more attention. In this paper, the properties of electromagnetic shielding yarns and fabrics were studied.Design/methodology/approachTen kinds of yarn, stainless steel short fiber and polyester blend yarn with three different blending ratios T/S 90/10, T/S 80/20 and T/S 70/30, stainless steel short fiber, polyester and cotton blend yarn with blending ratio C/T/S 35/35/30, core-spun yarn with one 30 um stainless steel filament C/T28tex/S(30 um), core-spun yarn with two 15 um stainless steel filaments (C/T28tex/S(15 um)/S(15 um)), twin-core-spun yarn with one 30 um stainless steel filament and one 50D spandex filament C/T28tex/S(30 um)/SP(50D), sirofil wrapped yarn with one 30 um stainless steel filament feeding from left S(30 um)+C/T28tex, sirofil wrapped yarn with one 30 um stainless steel filament feeding from right C/T28tex+S(30 um), sirofil wrapped yarn with two 15 um stainless steel filaments feeding from two sides S(15 um)+C/T28tex+ S(15 um), were spun. The qualities of spun yarns were measured. Then, for analyzing the electromagnetic shielding properties of fabrics made of different spun yarns, 20 kinds of fabrics were woven.FindingsThe tested results show that comparing to the T/S 80/20 blend yarn, the resistivity of composite yarns with the same ratio of the stainless steel filament is smaller. The possible reason is that comparing to the stainless steel short fiber, the conductivity of stainless steel filament is better because of the continuous distribution of stainless steel in the filament. Comparing with the core-spun yarn, the conductivity of the sirofil wrapped yarn is a little better. Comparing to the fabric woven by the blend yarn, the electromagnetic shielding of the fabric woven by the composite yarn is better, and comparing to the fabric woven by the core-spun yarn, the electromagnetic shielding of the fabric woven by the sirofil yarn is a little better. The possible reason is that the conduction network can be produced by the stainless steel filament wrapped on the staple fiber yarn surface in the fabric, and the electromagnetic wave can be transmitted in the network.Originality/valueIn this paper, the properties of electromagnetic shielding yarns and fabrics were studied. Ten kinds of yarn, including three stainless steel short fiber and polyester blend yarns, one stainless steel short fiber, polyester and cotton blend yarn, two core-spun yarns, one twin-core-spun yarn, three sirofil wrapped yarn, were spun. Then, for analyzing the electromagnetic shielding properties of fabrics made of different spun yarns, 20 kinds of fabrics were woven. The effects of fabric warp and weft densities, fabric structures, yarn kinds, yarn distributions in the fabric on electromagnetic shielding were analyzed.

2019 ◽  
Vol 32 (3) ◽  
pp. 338-355
Author(s):  
Xuzhong Su ◽  
Xuzhong Su ◽  
Xinjin Liu

Purpose As one kind of filament/staple fiber composite yarn, core spun yarn has been widely used, especially on Jeans. However, there is only one filament in the commonly used core spun yarn, such as spandex, and the performance of the one filament often is influenced during dyeing and finishing. Therefore, in the paper, twin-core spun yarns with two different filaments feeding simultaneously were spun on ring spinning frame modified by one kind of filament feeding numerical control device. The paper aims to discuss these issues. Design/methodology/approach Four kinds of twin-core spun yarns, cotton/spandex/PBT, cotton/spandex/CM800, cotton/spandex/T400, cotton/spandex/SPH with linear density 36.4tex/40D/50D were spun. For improving the covering effect of the two filaments, the filament feeding position, filament pre-drafting multiple, distance between two staple roving, designed twist factor of the core spun yarn were optimized. Findings It is shown that comparing with the core spun yarn, the breaking strength and elongation of the twin-core spun yarns are improved since the addition of another elastic filament, while the evenness is a little worse. Originality/value By using the twin-core spun yarns, corresponding knitted and woven fabrics are produced. Meanwhile, for simulating the dyeing and finishing process, the knitted fabrics were treated during the 150°C high temperature. It is shown that comparing with the fabrics produced by cotton/spandex yarn, addition of another elastic filament can improve the fabric strength and resistant and has positive effect on worsen prevention for high temperature treated fabric elastic recovery, and on change prevention during the dyeing and finishing process for fabric handle properties, and improves the fabric stability.


2019 ◽  
Vol 32 (4) ◽  
pp. 457-469
Author(s):  
Wei Yanhong ◽  
Xinjin Liu ◽  
Xuzhong Su ◽  
Zhao Zhimin

Purpose In order to develop high shape retention yarn and investigate the effects of spinning process and core yarn contents on the shape retention of yarn, in this paper, three kinds of yarns, JC/T400 18.5tex (55.6dtex) core-spun yarn, JC/T400 18.5tex (44.4dtex) core-spun yarn and JC18.5tex pure cotton yarn were spun by using the complete condensing Siro-spinning technology. The paper aims to discuss these issues. Design/methodology/approach In this paper, the core-spun yarns were spun by using the complete condensing spinning and Siro-spinning technology. Two key spinning processes, yarn twist factor and core yarn pre-draft ratio, were optimized by using the orthogonal test method first. Then, via the variable control method, the position of the core yarn, the position of the bell mouth and the center distance between two bell mouths were optimized, respectively, and corresponding optimal spinning process of the three yarns was determined. Finally, the yarns were spun under the optimal process, and the performance of the spun yarns was tested and compared. Findings Results show that the yarn twist factor affects yarn strength and hairiness, the position of bell mouth affects the evenness and hairiness of the yarn mainly, and the position of the core yarn affects the coverage and hairiness of the yarn. For the Z-twist spinning, the core yarn enters the front roller from the left side of two strands center, which is beneficial to improve the covering effect of core yarn, and reduce the pilling phenomenon of the yarn. The contents of core yarn affect indicators of the yarn shape retention, such as yarn strength, elastic recovery and abrasion resistance. Originality/value The shape retention of yarns affects the shape retention of fabrics, and the production of yarn with high shape retention is a key step in achieving shape retention of fabrics. At present, there are little studies on the shape retention of yarns, most researchers shave focused on shape retention of fabrics. Using the complete condensing Siro-spinning method to spin the core-spun yarn can improve the quality of the yarn. Compared with traditional ring-spinning yarns, the addition of the core yarn can improve the shape retention of the yarn.


Author(s):  
Sunny Pannu ◽  
Meenakshi Ahirwar ◽  
Rishi Jamdigni ◽  
B. K. Behera

The woven fabrics containing cotton/spandex core spun yarns possesses very vital properties of stretch, recovery and thus shape retention from the view point of wearing comfort and garment appearance. Spandex present in the core of core spun yarn is the most essential performer behind these properties. An attempt is made in this research work to study the influence of changing spandex denier in core spun yarn on the stretch and functional properties of stretch woven fabrics. The sole objective of this study is to find out whether different stretch, shrinkage and physical properties of stretch woven fabrics depend upon changing spandex percentage achieved by means of change in spandex filament denier. It was observed that by increasing denier of spandex in core spun weft yarns the increase in weft shrinkage diminishes. Dual core weft with spandex provides good elongation percentage and recovery percentage. The fabric with higher denier spandex in yarn shows a decreasing total hand values trend for summer and winter. The results depicts that the fabrics have higher THV for winter suiting fabrics as compared to summer suiting thus are more suitable for the winter wear.


2017 ◽  
Vol 29 (6) ◽  
pp. 754-767 ◽  
Author(s):  
Kumar K.V. ◽  
Sampath V.R. ◽  
Prakash C.

Purpose Air permeability of knitted fabrics is normally measured for the samples in their unstretched state. But, this air permeability values indicate the ability of these garments to allow air through them when they are not in use. But, the real-time condition is different and certainly the knitted garments mentioned above will subject to a degree of stretch during their usage. So, the measurement of air permeability under stretch and the fabric properties which would influence the air permeability of weft-knitted fabrics in their stretched state is of paramount importance. The paper aims to discuss these issues. Design/methodology/approach The aim of this research work is to investigate the change in air permeability values under the incremental extension of cotton tubular weft-knitted fabrics produced from the yarns of different spinning systems. Findings From the results, it is evident that the pique fabric samples of compact spun yarn displayed the highest air permeability values during the incremental stretch at all the three relaxation states. It is followed by the pique samples of ring spun yarn. Next to pique samples, the jersey samples made from the compact yarn and ring spun yarn revealed more air permeability, respectively. The core spun pique samples and core spun jersey samples displayed the least air permeability values, respectively. But, the pique and jersey samples made up of ring yarn and compact yarn showed gradual reduction in their air permeability towards the incremental stretch and the core spun pique samples and core spun jersey samples were uniformly seen with gradual increase in their air permeability during the incremental stretch. Originality/value Very limited quantity of research has been carried out in this area. So, a novel attempt has been made in this research work to investigate the influence of incremental stretch on air permeability of single knit structures.


2019 ◽  
Vol 31 (2) ◽  
pp. 181-194 ◽  
Author(s):  
Rafiu King Raji ◽  
Xuhong Miao ◽  
Shu Zhang ◽  
Yutian Li ◽  
Ailan Wan ◽  
...  

PurposeThe use of conductive yarns or wires to design and construct fabric-based strain sensors is a research area that is gaining much attention in recent years. This is based on a profound theory that conductive yarns will have a variation in resistance if subjected to tension. What is not clear is to which types of conductive yarns are most suited to delivering the right sensitivity. The purpose of this paper is to look at strain sensors knitted with conductive composite and coated yarns which include core spun, blended, coated and commingled yarns. The conductive components are stainless steel and silver coating respectively with polyester as the nonconductive part. Using Stoll CMS 530 flat knitting machine, five samples each were knitted with the mentioned yarn categories using 1×1 rib structure. Sensitivity tests were carried out on the samples. Piezoresistive response of the samples reveals that yarns with heterogeneous external structures showed both an increase and a decrease in resistance, whereas those with homogenous structures responded linearly to stress. Stainless steel based yarns also had higher piezoresistive range compared to the silver-coated ones. However, comparing all the knitted samples, silver-coated yarn (SCY) proved to be more suitable for strain sensor as its response to tension was unidirectional with an appreciable range of change in resistance.Design/methodology/approachConductive composite yarns, namely, core spun yarn (CSY1), core spun yarn (CSY2), silver-coated blended yarn (SCBY), staple fiber blended yarn (SFBY) and commingled yarn (CMY) were sourced based on specifications and used to knit strain sensor samples. Electro-mechanical properties were investigated by stretching on a fabric tensile machine to ascertain their suitability for a textile strain sensor.FindingsIn order to generate usable signal for a strain sensor for a conductive yarn, it must have persistent and consistent conductive links, both externally and internally. In the case of composite yarns such as SFBY, SCBY and CMY where there were no consistent alignment and inter-yarn contact, resistance change fluctuated. Among all six different types of yarns used, SCY presented the most suitable result as its response to tension was unidirectional with an appreciable range of change in resistance.Originality/valueThis is an original research carried out by the authors who studied the electro-mechanical properties of some composite conductive yarns that have not been studied before in textile strain sensor research. Detailed research methods, results and interpretation of the results have thus been presented.


2012 ◽  
Vol 7 (4) ◽  
pp. 155892501200700 ◽  
Author(s):  
Fatma Ceken ◽  
Gulsah Pamuk ◽  
Ozan Kayacan ◽  
Ahmet Ozkurt ◽  
Şebnem Seçkin Ugurlu

In this study, stainless steel conductive yarns with 500 tex fineness and 14 Ω/m linear resistances were inserted into the reverse side of the knitted fabrics made from acrylic yarns. Six types of knitted fabrics with conductive yarns were produced on an E=7 gauge electronic flat bed knitting machine. Then the electromagnetic shielding efficiency (EMSE) of the sample fabrics were measured in the frequency range of 750 MHz – 3000 MHz. The EMSE variations of the sample fabrics having conductive yarns with respect to fabric structure and polarization type (vertical and horizontal) were also investigated. It was observed that the same samples showed different behaviors and have dissimilar EMSE values in different polarization conditions. When compared to horizontal polarization measurements, the vertical measurement results gave better EMSE values.


2012 ◽  
Vol 83 (8) ◽  
pp. 849-858 ◽  
Author(s):  
Mustafa Sabri Ozen ◽  
Erhan Sancak ◽  
Ali Beyit ◽  
Ismail Usta ◽  
Mehmet Akalin

2018 ◽  
Vol 22 (3) ◽  
pp. 235-246
Author(s):  
Manik Bhowmick ◽  
Arup Kumar Rakshit ◽  
Sajal Kumar Chattopadhyay

Purpose Dref-3 friction spun core yarns produced using staple fibre yarn as the core, e.g. Jute core yarn wrapped with cotton fibre, have poorer mechanical properties compared to the core yarn itself. The purpose of this study was to understand the structure of such yarns, that will lead to the optimization of fibre, machine and process variables for production of better quality yarn from the Dref-3/3000 machines. Design/methodology/approach The Dref spinning trials were conducted following a full factorial design with six variables, all with two operative levels. The Dref-3 friction spun yarn, in which the core is a plied, twisted ring yarn composed of cotton singles and the sheath, formed from the same cotton fibres making the singles, has been examined. The structures have also been studied by using the tracer fibre technique. Findings It was observed that rather than depending on the plied core yarn, the tensile properties of the Dref-3 yarn are significantly determined by the parameters those affect the constituent single yarn tensile properties, i.e. the amount of twist and its twist direction, yarn linear density and the sheath fibre proportion used during the Dref spinning in making the final yarn. Further, when the twist direction of single yarn, double yarn and the Dref spinning false twisting are in the same direction, the produced core-sheath yarn exhibits better tensile properties. Practical implications The understanding of the yarn structure will lead to optimized production of all staple fibre core Dref spun yarns. Social implications The research work may lead to utilization of coarse and harsh untapped natural fibres to the production of value-added textile products. Originality/value Though an earlier research has reported the effects of sheath fibre fineness and length on the tensile and bending properties of Dref-3 friction yarn, the present study is the first documented attempt using the tracer fibre technique to understand Dref-3 yarn structure with plied staple fibrous core.


2021 ◽  
Vol 16 ◽  
pp. 155892502110591
Author(s):  
Osman Babaarslan ◽  
Md Abul Shahid ◽  
Fatma B Doğan

In recent decades, consumer expectations and behavior have altered, focusing on more comfortable, well-fitting clothes. Wearing a slim-fitting garment helps to move more freely. Different elastomeric polymers are being introduced as a core constituent of the yarn to make denim fabric more comfortable during movement. The use of elastic material ensures that the material is stretchable and recoverable. The performance of several elastomeric hybrid yarns has been investigated in the first section of this study. Here, polyethylene terephthalate/polytrimethylene terephthalate (PET/PTT (T400®)), polytrimethylene terephthalate (PTT (Solotex®)), polybutylene terephthalate (PBT), and Lycra® (elastane) were used as the core component of the core and dual core-spun yarns. After that, 3/1 Z twill denim fabrics were made with these as weft yarns, and the fabric’s performance was assessed. It is found that dual core-spun yarns were shown to have lower strength than core-spun yarns, while it had a higher elongation value. PTT/PBT dual core-spun yarn had less unevenness and hairiness than yarn made solely of elastane. PBT in the core of the weft yarns provided strong strength, dimensional change, and stiffness qualities in the fabric. In contrast, elastane in the core of the weft yarns provided good elastic performance. Yarn and fabric performance for the hybrid yarns were statistically significant at a significance level of 0.05.


2017 ◽  
Vol 12 (1) ◽  
pp. 155892501701200
Author(s):  
Esin Sarioğlu ◽  
Osman Babaarslan

Denim fabric is one of the most popular casual wear fabrics worldwide. The performance characteristics of denim fabrics have been improved by using functional fibers and elastane to make them comfortable to wear. Elastane fibers with high elasticity are used extensively in denim fabric production. Elastane fibers are generally used as the core part of the core-spun yarns as weft yarns. Besides elastane fibers; polyester and polyester derivatives are commonly used. This study examines the effects of filament fineness and yarn count on denim fabric performance. Textured polyester filaments with medium, fine and micro linear densities were used as the core part of the core-spun yarn and cotton fiber was used as sheath material. Yarn samples manufactured with the same production parameters at different yarn count were used as weft yarns of denim fabrics. Denim fabrics were produced with the same fabric cover factor to eliminate yarn count difference effects. Tensile, static tearing and dynamic tearing properties of denim fabrics were determined. To evaluate the effects of core part, 100 % cotton denim fabric was manufactured and tested. Statistical analysis was performed to analyze the significance of filament fineness and yarn count ratio. Results showed that there was a significant effect of filament fineness on tensile, static tearing and dynamic tearing properties of denim fabrics. In addition, it was found that yarn count had no significance effect on static tearing properties of denim fabrics.


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