Influence of re-entrant hexagonal structure and helical auxetic yarn on the tensile and auxetic behavior of parametric fabrics

2021 ◽  
pp. 004051752199349
Author(s):  
Junli Chen ◽  
Yonggui Li ◽  
Taohai Yan ◽  
Xiang Liu ◽  
Jiqiang Cao ◽  
...  
Keyword(s):  
Unit Length ◽  
Hexagonal Structure ◽  
Weft Yarn ◽  
Breaking Strain ◽  
Innovative Design ◽  
Fabric Structure ◽  
Optimizing Design ◽  
Plain Fabric ◽  
The Stability ◽  
Fabric Design

This paper focuses on systematically analyzing the influence of macro fabric structure and yarn architecture on the mechanical and auxetic performance of parametric auxetic fabrics. Re-entrant hexagonal (REH) and helical auxetic yarn (HAY) were adopted as a macro fabric structure and weft yarn to produce three kinds of auxetic fabrics: REH fabric with HAY as weft yarn (REH-HAY); REH fabric with elastic yarn as weft yarn (REH-1, REH-2, REH-3); and plain fabric with HAY as weft yarn (NREH-HAY). By controlling the existence of the HAY and REH structure, the influence of the REH structure and HAY on the mechanical and auxetic properties was thoroughly analyzed. It is demonstrated that both the REH macrostructure and HAY micro configuration can contribute to the performance of the auxetic fabric. Specifically, in the presence of the REH structure and HAY, the auxeticity was found to a 77% increase compared with NREH-HAY and the breaking strain and load rises by about 37.50% and 90.42%, respectively. Notably, the variation of the polyurethane (PU) weft yarn per unit length influenced the tensile and auxetic performance to a lesser extent, while by changing PU to HAY, a significant increase of negative Poisson’s ratio value from –1.155 to –1.492 was noticed without greatly jeopardizing the stretchability. Furthermore, the cyclic tensile results demonstrate the stability and elasticity of the fabric. The comparative analysis can give guidance to optimize fabric design and inspire the innovative design of the auxetic textiles, all of which will pave the way for a quantitative and optimizing design for auxetic textiles.

scholarly journals Evaluation of Bed Cover Properties Produced from Double Fabric Based on Honeycomb

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
A. A. Salama ◽  
A. S. El-Deeb ◽  
I. M. El-shahat
Keyword(s):  
Thermal Comfort ◽  
Water Vapour ◽  
Thermal Insulation ◽  
Abrasion Resistance ◽  
Air Permeability ◽  
Weft Yarn ◽  
Vapour Permeability ◽  
Geometrical Properties ◽  
Fabric Structure ◽  
Air Pockets

This research aims to innovate a new fabric structure, which could be used as a bed cover based on double honeycomb fabric with self-stitching. The honeycomb air pockets were aimed at facing each other to form closed small air chambers which work to sequester the air. The double fabric increases fabric thickness. Thus, the opportunity to improve thermal comfort could be achieved. A number of samples were produced with different densities and counts of weft yarn. Thermal insulation and water vapour permeability were measured and compared with bed covers produced from reversible weft backed structure. Geometrical properties, abrasion resistance, and air permeability were also measured. The results showed that the innovated structure had higher values of thermal insulation than reversible weft backed structure at certain weft counts and densities.

scholarly journals Effect of Fabric Structure and Weft Density on the Poisson's Ratio of Worsted Fabric

2013 ◽  
Vol 8 (2) ◽  
pp. 155892501300800 ◽  
Author(s):  
Nazanin Ezaz Shahabi ◽  
Siamak Saharkhiz ◽  
S. Mohammad Hosseini Varkiyani
Keyword(s):  
Poisson’S Ratio ◽  
Uniaxial Extension ◽  
Poisson's Ratio ◽  
Weft Yarn ◽  
Combination Effect ◽  
Weft Direction ◽  
Weave Structure ◽  
Fabric Structure ◽  
Fabric Structures ◽  
High Linear Correlation

This paper investigates the impacts of weave structures and weft density on the Poisson's ratio of worsted fabric under uniaxial extension. In this study nine groups of worsted fabrics comprising of three weave structures (twill 2/2, twill 3/1 and hopsack 2/2), each produced in three different weft densities were examined. Samples were extended in weft direction uniaxially and the Poisson's ratio of fabric in various extensions was measured. Analysis showed that the effect of both weft density and weave structure are significant with no combination effect on the Poisson's ratio. It was found that there is an exponential correlation between warp and weft crimp during fabric extension. For the worsted fabrics used in this research in all three fabric structures, fabrics with higher weft yarn density have higher value of Poisson's ratio. It was also concluded that for the fabrics with the same condition but only different in structures, this ratio is related to the structural firmness of fabric. In all three fabric structures the value of the Poisson's ratio were following the same pattern of twill 2/2, twill 3/1 and hopsack 2/2 from highest to lowest value. It was revealed that there is a high linear correlation between the crimp interchange ratio and Poisson's ratio.

The Stability of Weft Insertion of CRT – 83 Carpet Rapier Loom

2013 ◽  
Vol 457-458 ◽  
pp. 684-687
Author(s):  
Yong Dong Cai ◽  
Shun Bin Ma
Keyword(s):  
Theoretical Analysis ◽  
Initial Deformation ◽  
Weft Yarn ◽  
High Grade ◽  
Release Times ◽  
Factors Influencing ◽  
Main Factors ◽  
The Stability ◽  
Theory Research

CRT- 83 carpet rapier loom is a kind of high-grade rigid rapier loom，the weft yarn will give looms to demand higher stability of the weft insertion. Theoretical analysis based on the theory research of the stability of clamping weft and weft handover shows that the rapier deformation，slipping force and the depth of clamping are main factors influencing the stability of weft insertion.In order to obtain reasonable process of weft insertion，concerned with the following factors：the grip length and outrigger length of rapier，release times of clip yarn device，initial deformation angle of spring piece.

Effect of weave structure on the slicing cut resistance of woven fabrics

2019 ◽  
Vol 90 (13-14) ◽  
pp. 1477-1494
Author(s):  
Magdi El Messiry ◽  
Shaimaa El-Tarfawy
Keyword(s):  
High Performance ◽  
Normal Load ◽  
Cutting Speed ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Weft Yarn ◽  
Fabric Structure ◽  
Yarn Count ◽  
Highly Correlated ◽  
Cutting Processes

Cutting processes using blades have found applications in many industries; for example, in garments, fiber–polymer composites, and high-performance fabric forming. In recent decades, the process of cutting the material using a robotic-controlled blade has raised concern about the value of the pressure and the cut force required for a certain type of woven fabric and the estimation of its value before the pressing and cutting process. A simple theoretical relation was established based on the fabric structure and yarn shear stress. The model formulation and experimental results to describe the basic theory of blade cutting fracture for woven fabric of different designs was derived. In this work, the experimental investigation of the effect of the fabric specifications, normal load, and the cutting speed on the cutting force was carried out, which indicates that the value of the specific cutting resistance of the fabric was found to be highly correlated with the fabric structure, warp and weft yarn count, Young’s modulus of the fabric, and fractional cover factors ratio ζ.

Finite Element Analysis on Stability for Elastic-Jumping Membrane

2011 ◽  
Vol 287-290 ◽  
pp. 717-722 ◽  
Author(s):  
Zhen Ting Wu ◽  
Shun Jiang Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Critical Load ◽  
Element Model ◽  
Structure Parameter ◽  
Element Analysis ◽  
Factors Influencing ◽  
Optimizing Design ◽  
Main Factors ◽  
The Stability

In order to increase the designing precision and study the main factors influencing the stability of metal elastic-jumping membrane, a set of experimental equipments have been designed to test the stability of metal elastic-jumping membrane. The laws of influencing the stability of elastic-jumping membrane were studies by changing the thickness, high, radius etc structure parameter. It shows that the increasing of high and thickness can enhance the distortion rigidity of metal elastic-jumping membrane, result in the increase of critical load at losing stability; the increasing of diameter can reduce the distortion rigidity of metal elastic-jumping membrane, result in the decrease of critical load at losing stability. At the same time, the correctness of finite element model was confirmed, and the basis was established for finite element method applying in optimizing design of metal elastic-jumping membrane.

Structural design and characterization of highly elastic woven fabric containing helical auxetic yarns

2019 ◽  
Vol 90 (7-8) ◽  
pp. 809-823
Author(s):  
Junli Chen ◽  
Zhaoqun Du ◽  
Tianyuan Li
Keyword(s):  
Woven Fabric ◽  
Energy Harvest ◽  
Weft Yarn ◽  
Great Promise ◽  
Functional Textiles ◽  
Fabric Structure ◽  
Essential Properties ◽  
Daily Application ◽  
Break Load

Auxetic textiles have been the focus of much attention due to their great promise for advanced protective clothing, flexible energy harvest devices, and functional textiles. Herein, plain fabric, basket fabric, and a derivative weave with the warp and weft yarns arrangement in a series of zigzags were prepared by incorporating different initial wrap density helical auxetic yarns in the weft direction using a commercial semi-automatic loom. The derivative weave using HAYs with a 150 m−1 initial wrap density as the weft yarn not only possesses superior auxetic behavior but also has good performance in strength and elasticity—essential properties useful for textile daily application. This fabric exhibits a high auxetic effect ( ν = −0.585), low elastic deformation (total deformation of 8.4% at 20% strain), excellent flexibility, and high break load. Moreover, by taking account of the key geometric parameters, a systematic discussion of the fabrics has been completed to evaluate the effect on the auxetic behavior; this clarified that changing the fabric structure and initial wrap density of a HAY is an effective strategy to tailor auxetic behavior without compromising the intrinsic properties of components. On the basis of our research, auxetic textiles can be considered a promising candidate for next-generation smart textiles and advanced functional textiles.

The solar properties of fabrics produced using different weft yarns

2017 ◽  
Vol 88 (13) ◽  
pp. 1543-1558 ◽  
Author(s):  
Kenan Yildirim ◽  
Asuman Kanber ◽  
Mehmet Karahan ◽  
Nevin Karahan
Keyword(s):  
Linear Density ◽  
Unit Length ◽  
Test Method ◽  
Dominant Factor ◽  
Weft Yarn ◽  
Test Results ◽  
Fiber Composition ◽  
Density Factor ◽  
Yarn Structure ◽  
Yarn Hairiness

Woven fabric is composed of two yarns system, known as the weft and warp yarns. Each yarn system has an effect on the physical, performance, and optical properties of fabric. Any change in one or both yarn systems greatly alters the fabric properties. The solar and luminous properties of fabrics are also affected by altering the weft yarn or both yarn systems. This study investigates the effect of altering the weft yarn system on the solar and luminous properties of fabrics. The differences in the weft yarn in the fabrics were based on the weft yarn structure, including the yarn linear density, amount of twist on the yarn, yarn evenness, hairiness, spinning method, fiber composition of the yarn, and weft density of the fabric. The fabric luminous and solar properties were measured according to EN 14500 using an ultraviolet-visible-near-infrared (UV/VIS/NIR) test device and calculated from the EN 410 standard test method. According to a variance analysis, the weft density factor is shown to have an effect on the solar properties of the fabric, especially the UV transmittance properties of the fabric. Although non-parametric test results with a 95% confidence level show that the yarn structure does not influence the solar characteristics of the fabric, we show from the test results that the yarn structure influences the solar properties of the fabric. Yarn hairiness was the dominant factor for the IR and visible portions of the solar radiation spectra. In the UV region, the fiber composition factor was found to be important. The effect of the yarn linear density was similar to the effect of the weft density factor. The solar transmittance decreases and the reflectance increases when the number of weft yarns per unit length is increased and the yarn linear density in the Ne numbered system is decreased. Increasing the yarn hairiness decreases the transmittance in the IR portion of the solar spectra. The degree of influence that the yarn structure has on the solar properties (with the exception of the UV portion) of the fabric was dominated by the number of weft yarns per unit length. The transmittance properties of the fabric were more affected by altering the yarn structure than the reflectance and absorbance properties.

Color Prediction for Weft-All-Coloring Jacquard Fabric Based on the Two-Constant Kubelka-Munk Theory

2011 ◽  
Vol 418-420 ◽  
pp. 2278-2281 ◽  
Author(s):  
Hua Zhou ◽  
Chun Yan Wang ◽  
Jiu Zhou
Keyword(s):  
Color Difference ◽  
Weft Yarn ◽  
Absorption Coefficients ◽  
Scattering Coefficients ◽  
Fabric Structure ◽  
Color Prediction ◽  
Fabric Structures ◽  
Fitting Error

Weft-all-coloring jacquard fabric is smoother and plentiful. It looks stereoscopic impression. Because of complex fabric structures, color designing of jacquard fabric still remains a problem to be solved. In addition, there have not ideal colorful model to predict jacquard fabric structure. In view of the above problems, this study use four primary samples that red, yellow, green are used in weft yarn and white is used in warp to prepare many weft-all-coloring jacquard fabric of single-warp and double-weft. Though a large number of experimental color about a data-color 600 plus spectrophotometric, the theory of Kubelka-Munk absorption coefficients (K) and scattering coefficients (S) of all yarns and the color proportion of weft were calculated for jacquard fabric. The results indicate that the color difference is 1.5 CIELAB units, and the fitting error of the yarn’s proportion is about 2.1%. It shows that the two-constant Kubelka-Munk theory is suitable for predicting the color of weft jacquard fabric with all-coloring and color proportion.

scholarly journals Molecular Shape of the Cationic Lipid Controls the Structure of Cationic Lipid/Dioleylphosphatidylethanolamine-DNA Complexes and the Efficiency of Gene Delivery

2001 ◽  
Vol 276 (50) ◽  
pp. 47615-47622 ◽  
Author(s):  
Jarmila S̆misterová ◽  
Anno Wagenaar ◽  
Marc C. A. Stuart ◽  
Evgeny Polushkin ◽  
Gerrit ten Brinke ◽  
...  
Keyword(s):  
Transfection Efficiency ◽  
Cationic Lipid ◽  
Molecular Shape ◽  
Hexagonal Structure ◽  
Structure Stability ◽  
Dna Complexes ◽  
Cross Sectional ◽  
X Ray Scattering ◽  
Lipid Control ◽  
The Stability

Pyridinium amphiphiles, abbreviated as SAINT, are highly efficient vectors for delivery of DNA into cells. Within a group of structurally related compounds that differ in transfection capacity, we have investigated the role of the shape and structure of the pyridinium molecule on the stability of bilayers formed from a given SAINT and dioleoylphosphatidylethanolamine (DOPE) and on the polymorphism of SAINT/DOPE-DNA complexes. Using electron microscopy and small angle x-ray scattering, a relationship was established between the structure, stability, and morphology of the lipoplexes and their transfection efficiency. The structure with the lowest ratio of the cross-sectional area occupied by polar over hydrophobic domains (SAINT-2) formed the most unstable bilayers when mixed with DOPE and tended to convert into the hexagonal structure. In SAINT-2-containing lipoplexes, a hexagonal topology was apparent, provided that DOPE was present and complex assembly occurred in 150 mmNaCl. If not, a lamellar phase was obtained, as for lipoplexes prepared from geometrically more balanced SAINT structures. The hexagonal topology strongly promotes transfection efficiency, whereas a strongly reduced activity is seen for complexes displaying the lamellar topology. We conclude that in the DOPE-containing complexes the molecular shape and the nonbilayer preferences of the cationic lipid control the topology of the lipoplex and thereby the transfection efficiency.

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