scholarly journals Effect of Lycra Percentages and Loop Length on the Physical and Mechanical Properties of Single Jersey Knitted Fabrics

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Eman Eltahan

Single jersey knitted fabrics are generally used to make underwear and outerwear such as T-shirts. Knit fabric can more easily deform or stretch by compressing or elongating the individual stitches that form the fabric. Cotton yarns, which are not elastomeric, do not have the ability of recovery to rearrange the stitches. As a consequence, single-knit fabrics may have permanent deformation. To improve the recovery performance of circular single-knit fabrics, it is now a common practice to knit a small amount of spandex fiber or yarn with companion cotton yarn. In this study the physical, dimensional, and mechanical properties of back plaited cotton/spandex single jersey knitted fabrics were investigated and the results are compared with knitted fabrics made from 100% cotton and the effect of spandex percentage was also studied. It was found that as the loop length increases, the wales density was not affected and specific fabric hand and extension increased, but bursting strength and fabric recovery decreased. The presence of Lycra in single jersey knitted fabric increases of course density, fabric thickness, and knitted fabric recovery, while fabric width, fabric porosity, and extension were decreased.


2019 ◽  
Vol 2 (3) ◽  
pp. 317-323
Author(s):  
Mehmet Erdem İnce

The fact that weft knitted fabrics has a stretchable, 3D, porous and interlocking structure makes them unique when manufactured from high performance fibers. Knitted fabrics with different architectures exhibit different properties. Different loop forms like tuck and skip stitches with various loop lengths reveal different physical and mechanical properties. Literature review indicated that wisely arrangement of tuck stitches within the pattern repeat alter the weft-knitted fabric structure from natural and synthetic fibers. Therefore, we studied the effect of number and location of tuck stiches on air permeability of weft-knitted fabrics from glass yarn. Single-bed, flat weft knitting machine was used to knit fabrics with different architectures from three-ply glass yarn. The nominal single-end count of used E-glass yarn was 136 tex. It is anticipated that the number and location of tuck stitches within knit pattern effect physical and air permeability properties of weft-knitted fabrics from glass yarn.



2014 ◽  
Vol 26 (3) ◽  
pp. 222-234 ◽  
Author(s):  
E. Perumalsamy ◽  
J.C. Sakthivel ◽  
N. Anbumani

Purpose – The purpose of this paper is to elucidate the stress-strain relationships of single-jersey knitted fabrics from uniaxial tensile test followed by deformation behavior using finite element analysis. In order to elaborate the study, high, medium and low tightness knitted fabrics were selected and deformation of fabrics analyzed in course, wales and bias directions (0, 45 and 90 degrees). Design/methodology/approach – This study focussed on uni-axial tensile test of produced test samples using Instron 6021 tester and a development of single-jersey knitted loop model using Auto Desk Inventor software (ADI). The knitted fabric material properties and knitted loop model was imported to ANSYS 12.0 software. Findings – Due to structural changes the tightness and thickness of knitted fabric decreases with increase in loop length The tensile result shows maximum breaking strength at course direction (13.43 kg f/mm2 at 2.7 mm) and maximum extension at wales direction (165.77 kg f/mm2 at 3.3 mm). When the loop length increases, the elongation of fabrics increased and load carrying capacity of fabrics reduced. The Young's modulus, Poisson's ratio and shear modulus of fabrics reduced with increase in loop length. The deformation of fabrics increased with increase in loop length. The increase in loop length gives large amount of structural changes and it is due to slacking or jamming in loops and loosening in dimensions. When comparing the deformation results, the variation within the fabric is higher and structural damage little more when increasing the loop length of the fabric. Originality/value – From ANOVA test, stress and strain distribution was statistically significant among course, wales and bias directions at 95 percent confidence level. The values got from Instron test indicates that testing direction can alter its deformation. In deformation analysis, comparing both experimental and prediction, high amount of structural changes observed in wales direction. The used tetrahedral elements can be used for contact analysis with high accuracy. For non-linear problems, consistent approach was proposed which makes the sense to compare with experimental methods. The proposed model will make possible developments and the preliminary validation tests shows good agreement with experimental data.



2017 ◽  
Vol 17 (2) ◽  
pp. 152-163 ◽  
Author(s):  
Anindya Ghosh ◽  
Prithwiraj Mal ◽  
Abhijit Majumdar ◽  
Debamalya Banerjee

Abstract Knitted fabrics have excellent comfort properties because of their typical porous structure. Different comfort properties of knitted fabrics such as air permeability, thermal absorptivity, and thermal conductivity depend on the properties of raw material and knitting parameters. In this paper, an investigation was done to observe the effect of yarn count, loop length, knitting speed, and yarn input tension in the presence of two uncontrollable noise factors on selected comfort properties of single jersey and 1×1 rib knitted fabrics using the Taguchi experimental design. The results show that yarn count and loop length have significant influence on the thermo-physiological comfort properties of knitted fabrics.



2021 ◽  
Vol 304 ◽  
pp. 03034
Author(s):  
Sadoqat Rahmatova ◽  
Nozimjon Jurabayev ◽  
Qurbonali Holikov

In this research work, the physical and mechanical properties of 3 variants of jacquard knitted fabric obtained in order to increase the heat retention properties and increase the range of knitted fabrics by adding back yarn to the base of glad, rubber cuts in 20 grade double-needle jacquard knitting machine using local raw materials effectively The technological indicators were obtained experimentally and tabulated and recommendations for production sectors are given.



2021 ◽  
Vol 29 (1(145)) ◽  
pp. 53-56
Author(s):  
V. Kumar ◽  
C. Prakash ◽  
G. Manigandan ◽  
V.R. Sampath

Most of the time, a certain degree of stretch prominently and incrementally occurs in intimate wear, leisure wear, sportswear, medical textiles etc., during their action. Variations in the stretch gradient would definitely cause changes in the air permeability of knitted fabrics. The influence of variables such as loop length, the presence of an elastomeric component and fabric structure on the air permeability of cotton single jersey and pique knitted fabrics in a stretched state was critically analysed. In this work, changes in the air permeability of cotton jersey samples with and without elastomer were investigated and reported by keeping the samples in static up to an incremental stretch of 40% at a rate of 10% of the stretch gradient, in a dry relaxed state, wet relaxed state and fully relaxed state.



2013 ◽  
Vol 8 (3) ◽  
pp. 155892501300800 ◽  
Author(s):  
Mitra Karimian ◽  
Hossein Hasani ◽  
Saeed Ajeli

This research investigates the effect of fiber, yarn and fabric variables on the bagging behavior of single jersey weft knitted fabrics interpreted in terms of bagging fatigue percentage. In order to estimate the optimum process conditions and to examine the individual effects of each controllable factor on a particular response, Taguchi's experimental design was used. The controllable factors considered in this research are blending ratio, yarn twist and count, fabric structure and fabric density. The findings show that fabric structure has the largest effect on the fabric bagging. Factor yarn twist is second and is followed by fabric density, blend ratio and yarn count. The optimum conditions to achieve the least bagging fatigue ratio were determined.



2016 ◽  
Vol 88 (4) ◽  
pp. 467-479 ◽  
Author(s):  
Ka-yan Yim ◽  
Chi-wai Kan

Fabric hand is an indispensable characteristic for the selection of fabric and product development and the buying consideration for manufacturers and consumers. However, there is little comprehensive work on the hand feel property of warp-knitted fabrics due to the mainstream natural fibers (cotton, wool and silk) and other fabric structures (woven, weft-knitted and nonwoven). The increasing potential for the wide variety of applications and development of warp-knitted fabrics is not only because its fabric hand gives better determination for fabric marketing, but also because it provides extensive scope for fabric performance and appearance. This paper reports an experimental study on the integrated fabric hand behavior of a series of warp-knitted fabrics made for various apparel applications, such as sportswear, lingerie and leisure wear. These 105 fabrics were produced by varying different physical parameters, including fabric weight and fabric thickness. The Kawabata Evaluation System for Fabric (KES-F) was employed to obtain the fabric hand properties (primary hand value and total hand value) related with stiffness, smoothness and softness. All low-stress mechanical properties and fabric hand values from the testing results were used to verify the applicability of the KES-F on warp-knitted fabrics and to analyze the relationships of fabric parameters and hand characteristics. The results indicate that the KES-F is an appropriate tool to measure the hand attributes of warp-knitted samples, and moderate correlations between physical properties and mechanical behavior were found.



2017 ◽  
Vol 12 (1) ◽  
pp. 155892501701200
Author(s):  
Züleyha Değirmenci ◽  
Ebru Çoruh

This paper reports the effect of loop length and raw material on the air permeability and the bursting strength of plain knitted fabrics. In this study, a series of plain knitted fabrics were produced on a circular knitting machine with cotton, polyester, acrylic and viscose by Ne 30/1 yarns. Each fabric type was produced with four different stitch lengths. All the fabrics were knitted at the same machine setting in order to determine the effect of their structure on the fabric properties. Their geometrical and physical properties were experimentally investigated. The influences of the loop length and the raw material on the number of the courses per cm, number of the wales per cm, loop shape factor, thickness, fabric unit weight, tightness factor, air permeability and bursting strength are analyzed. Statistical analysis indicates that raw material and loop length significantly parameters affect the air permeability and the bursting strength properties of the fabrics.



2014 ◽  
Vol 9 (4) ◽  
pp. 155892501400900
Author(s):  
Ivana Salopek Cubric ◽  
Vesna Marija Potocic Matkovic ◽  
Zenun Skenderi

In order to investigate the changes of knitted fabric properties due to exposure to outdoor natural weathering, a series of single jersey fabrics made from different raw materials was produced. The fabrics were exposed to summer weather conditions in duration of three months. The exposure of knitted fabrics to outdoor natural weathering in the summer period affected all investigated properties, namely, structural properties, tensile properties and heat resistance. The most significant changes were: the vertical density increased up to 31%, the mass per unit area increased up to 26%, the breaking force decreased in both directions for up to 54% and the heat resistance decreased up to 18%.



Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3539
Author(s):  
Jan Majernik ◽  
Stefan Gaspar ◽  
Jan Kmec ◽  
Monika Karkova ◽  
Jozef Mascenik

The mechanical properties of die castings correlate with the inner structure of a casting, distribution of the eutectic phases, and with the content and distribution of porous cavities in the casting volume. This submitted paper deals with the issue of the possibility to influence the basic parameters affecting the quality of castings through structural modifications of the gating system. The structural parameter under assessment is the gate height. In the case of the diverse height of the gate, five sets of castings were produced. The individual sets of castings were subjected to examination of selected mechanical properties, i.e., of permanent deformation and surface hardness. At the same time, the individual sets of castings were subjected to metallographic examination of the eutectic structure of the casting. It was proved that the gate height influences the aforementioned properties of the castings and significantly affects the ratio of the eutectic phases in the volume of the casting. The conclusion describes the mutual correlation between the gate structure, the mechanical properties of the casting, and its structural composition.



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