Auxetic behavior of warp knitted fabric under repeating tension

2021 ◽  
pp. 004051752198927
Author(s):  
Zhao Shuaiquan ◽  
Chang Yuping ◽  
Yang Yadie ◽  
Zhang Minglonghai ◽  
Hasan Karmurl ◽  
...  
Keyword(s):  
Tensile Test ◽  
Tensile Strain ◽  
Knitted Fabric ◽  
Knitted Fabrics ◽  
Tensile Strains ◽  
Warp Knitted Fabric ◽  
Better Than

In our previous study, a novel class of auxetic warp knitted fabrics were developed and their auxetic behaviors were studied under a single tensile test. However, during daily use, the fabrics are usually subjected to repeating tension rather than single tension. Therefore, the durability of the fabrics’ auxetic performance is of great importance. So far, the auxetic behavior of fabrics under repeating tension has not systematically been investigated. In this paper, we report a study on the auxetic behavior of warp knitted fabrics under repeating tension. All the fabric samples were subjected to a repeating tensile test within a tensile strain of 25% until 100 tensile cycles. The results show that the fabrics can keep their auxetic effect in both course and wale testing directions after 100 tensile cycles, and the auxetic effect in the wale direction is retained longer under higher tensile strains than that under lower tensile strains with the increase of tensile cycles. The results also indicate that auxetic stability in the course direction is much better than that in the wale direction. We hope that this study can offer useful information to improve the auxetic stability of auxetic fabrics for practical use.

Mechanical Response and Damage Analysis of 3D Multi-Structured Knitted Composite under Quasi-Tensile Loadings

2012 ◽  
Vol 476-478 ◽  
pp. 767-770
Author(s):  
Xi Wen Jia ◽  
Jia Zhi Su ◽  
Yi Zhu Zheng ◽  
Bo Hong Gu ◽  
Bao Zhong Sun
Keyword(s):  
Composite System ◽  
Mechanical Response ◽  
Strain Curve ◽  
Damage Mechanism ◽  
Core Material ◽  
Knitted Fabric ◽  
Knitted Fabrics ◽  
Initiation And Propagation ◽  
Damaged Zone ◽  
Warp Knitted Fabric

The mechanical response and damage mechanism of a 3D multi-structured knitted composite under quasi-tensile loadings are investigated based on experimental results. The multi-structured knitted composite consists of two knitted fabrics with weft double-faced interlock knitted fabric as core material and biaxial warp-knitted fabric as surface layer in the above-mentioned composite system, respectively. The tensile stress against strain curve is obtained to analyze the mechanical behavior. Furthermore, the failure mechanisms of 3D multi-structured knitted composite are discussed from the experimental observations by the initiation and propagation of damaged zone in knitted composites.

Investigation of the Two-Bar Warp-Knitted Fabric Structure Effect on Luster Value

2014 ◽  
Vol 9 (2) ◽  
pp. 155892501400900
Author(s):  
Saeed Ajeli ◽  
Zoleykhah Ahmadvand
Keyword(s):  
Diffuse Reflection ◽  
Specular Reflection ◽  
Knitted Fabric ◽  
Knitted Fabrics ◽  
Fabric Structure ◽  
Measuring Surface ◽  
Before And After ◽  
Dark Color ◽  
Points Of View ◽  
Warp Knitted Fabric

Consumer points of view determine economical value of fabrics. Fabric luster plays a momentous role in attracting people's attention, especially for clothing and domestic purposes. Luster is defined by intensity of both specular and diffuse light reflection off of a surface. There are various methods for measuring surface luster. Gloss. Luster is described as the ratio of specular reflection in one angle to diffuse reflection in another angle. Two-bar warp knitted polyester fabrics such as Tricot, Locknit, Satin, reverse Locknit and Sharkskin in three different densities were provided. A mini gloss apparatus was applied to measure fabric specular reflection in the angle of sixty degrees, before and after disperse dying with different colors of white, blue and yellow. Results suggest that luster is a function of knitted fabric type, color and density. Enhancement of technical back luster resulted from longer underlap of the front bar. However, it did not change the technical face luster significantly. Density increased in all knitted fabrics and caused the luster to decrease. Dark color fabrics showed lower luster compared to light ones.

Comparison of methods for measurement of the pressure exerted by knitted fabrics

2016 ◽  
Vol 87 (17) ◽  
pp. 2117-2126 ◽  
Author(s):  
Małgorzata Cieślak ◽  
Agnieszka Karaszewska ◽  
Ewa Gromadzińska ◽  
Izabela Jasińska ◽  
Irena Kamińska
Keyword(s):  
In Vitro Tests ◽  
Knitted Fabric ◽  
In Vitro Test ◽  
Knitted Fabrics ◽  
Weft Knitted Fabric ◽  
In Vivo Tests ◽  
Vitro Test ◽  
Warp Knitted Fabric

The article presents the results of measurements of pressure exerted by two model knitted products – bands with different structure (WI jersey weft-knitted fabric and WII openwork warp-knitted fabric). The tests were carried out with using the I-Scan system (in vivo and in vitro tests) and the STM 579 device (in vitro test). A comparative analysis of the in vivo and in vitro results for the I-Scan method and in vitro results for the I-Scan and STM 579 method was performed. It was found that the pressure values are lower for openwork warp-knitted fabric than for jersey weft-knitted fabric both in the case of the in vitro and in vivo tests, and the values of pressure for the same band are higher in the case of the in vitro tests.

The Axial Warp-Knitted Fabric and its Reinforced Composite

2011 ◽  
Vol 332-334 ◽  
pp. 837-840
Author(s):  
Yi Hua Bu ◽  
Yan Feng ◽  
Hua Wu Liu
Keyword(s):  
Mechanical Properties ◽  
Woven Fabrics ◽  
Advanced Materials ◽  
Knitted Fabric ◽  
Knitted Fabrics ◽  
Unique Structure ◽  
Reinforced Composite ◽  
And Performance ◽  
Warp Knitted Fabric ◽  
Composite Reinforcement

The structure and performance of the axial warp-knitted composite were introduced, including bi-axial and multi-axial organizations. According to the unique structure of this fabric, the mechanical properties and the advantages as a composite reinforcement were compared with regular staple woven fabrics. The advantages of composites reinforced by bi-axial and multi-axial knitted fabrics were discussed and the applications of such advanced materials were briefly presented.

Pilot Study of PET/Bamboo Charcoal Warp-Knitted Fabric

2012 ◽  
Vol 184-185 ◽  
pp. 1090-1093 ◽  
Author(s):  
Jia Horng Lin ◽  
Ching Wen Lin ◽  
Chin Mei Lin ◽  
Yi Chang Yang ◽  
Ting Ting Li ◽  
...  
Keyword(s):  
Far Infrared ◽  
Air Permeability ◽  
Weft Yarn ◽  
Knitted Fabric ◽  
Bamboo Charcoal ◽  
Health It ◽  
Warp Yarn ◽  
Knitted Fabrics ◽  
Far Infrared Ray ◽  
Warp Knitted Fabric

In recent years, as improvement of human living life, people begin to focus on themselves health. It is certain that bamboo charcoal has many properties, including water purification, deodorization, anion release and far-infrared ray radiation. This study aims to prepare PET/BC warp-knitted fabric composed of polyester yarn (PET) as warp yarn and bamboo charcoal polyamine yarn (BC) as weft yarn using Velcro Crochet Machine. Afterwards, air permeability, elastic resilience and far-infrared ray emissivity of resulting knitted fabric were discussed by changing weft yarn type. Result shows that, for knitted fabrics, weft yarn type cannot affect the elastic resilience; yet PET weft yarn makes air permeability decreasing.

Prediction of deformation behavior of single jersey cotton knitted fabrics using finite element method

2014 ◽  
Vol 26 (3) ◽  
pp. 222-234 ◽  
Author(s):  
E. Perumalsamy ◽  
J.C. Sakthivel ◽  
N. Anbumani
Keyword(s):  
Finite Element ◽  
Tensile Test ◽  
Deformation Behavior ◽  
Structural Changes ◽  
Knitted Fabric ◽  
Loop Length ◽  
Loop Model ◽  
Knitted Fabrics ◽  
Content Type ◽  
Single Jersey

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.

scholarly journals The Comfort Properties of Two Differential-Shrinkage Polyester Warp Knitted Fabrics

2016 ◽  
Vol 16 (2) ◽  
pp. 90-99 ◽  
Author(s):  
Qing Chen ◽  
Xuhong Miao ◽  
Haiwen Mao ◽  
Pibo Ma ◽  
Gaoming Jiang
Keyword(s):  
Evaluation System ◽  
Subjective Evaluation ◽  
Knitted Fabric ◽  
Polyester Yarn ◽  
Mechanical Pressure ◽  
Knitted Fabrics ◽  
Vapour Permeability ◽  
Fabric Handle ◽  
Differential Shrinkage ◽  
Warp Knitted Fabric

AbstractSingle-layered warp knitted fabrics were produced by the 60D/36F (containing 36 filaments) polyester yarn with differential shrinkage (DS) property in this study. Due to the differential shrinkage property, the fabric becomes curly and bulkier, simulating cotton fabric in terms of its appearance and fabric handle. The performance and appearance of these DS polyester warp knitted fabrics were evaluated objectively and subjectively. The testing results demonstrated that the DS polyester warp knitted fabric had better abrasion property, worse pilling resistance due to the mechanical property of polyester yarn when compared with 100% cotton warp knitted fabric. Meanwhile, lower water vapour permeability and air resistance were found for DS polyester warp knitted fabric resulting from the dense structure of yarn shrinkage after heat-moisture treatment. Besides, the fabric handle was evaluated by Kawabata evaluation system and subject to trial under dry and wet fabric condition. DS polyester warp knitted fabrics provide better recovery under low stress mechanical pressure. The subjective evaluation result shows that the warp knitted fabrics made of DS polyester had similar handle against cotton warp knitted fabric in terms of prickle, smooth, comfort and dry feeling in both dry and wet testing conditions.

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