Effect of Weft Binding Structure on Compression Properties of Three-Dimensional Woven Spacer Fabrics and Composites

With the wide use of three-dimensional woven spacer composites(3DWSCs),the market expects greater mechanical properties from this material.By changing the weft fastening method of the traditional I-shape pile yarns,we designed three-dimensional woven spacer fabrics(3DWSFs)and 3DWSCs with the weft V-shape to improve the compression performance of traditional 3DWSFs.The effects of weft binding structures,V-pile densities,and V-shaped angle were investigated in this paper.It is found that the compression resistance of 3DWSFs with the weft V-shape is improved compared to that with the weft I-shape,the fabric height recovery rate is as high as 95.7%,and the average elastic recovery rate is 59.39%.When the interlayer pile yarn density is the same,the weft V-shaped and weft I-shaped 3DWSCs have similar flatwise pressure and edgewise pressure performance.The compression properties of the composite improve as the density of the V-pile yarns increases.The flatwise compression load decreases as the V-shaped angle decreases.When the V-shaped angle is 28°and 42°,the latitudinal V-shaped 3DWSCs perform exceptionally well in terms of anti-compression cushioning.The V-shaped weft binding method offers a novel approach to structural design of 3DWSCs.

Curriculum Reform of“Woven Fabric Structure Design and Application”in Higher Vocational College Based on Industry-College Partnerships

The curriculum“Woven Fabric Structure Design and Application”is the core curriculum of textile majors in higher vocational colleges,which plays a very important role in the cultivation of students’vocational ability and professional quality.The curriculum reform of“Woven Fabric Structure Design and Application”through the deep cooperation of industry-college partnerships,the comprehensive analysis of the major training objectives and graduation requirements,the redesign of the curriculum teaching content,the improvement of the teaching method and the examination method,has achieved good results.

Fabrication of Two-dimensional Monolayer and One-dimensional Wire of Zn-tetra-[3,5-di-t-butylphenyl]-porphyrin on Cu(100) Surface

We describe in this paper the fabrication of two- and one-dimensional nanostructures with organic molecular beam epitaxy （OMBE） principle based on controlled selfassembly by using adsorbate-substrate and intennolecular interactions that are important in molecular fabrication. Cu（100） single crystal was used as substrate in fabricating molecular nanostructures. Scanning tunneling microscopy （STM） experiments confirmed that Zn-tetra- [3,5-di-t-butylphenyl]porphyrin-molecules can be used to fabricate both monolayer and molecular wire on Cu（100） surface simultaneously, and the latter is arranged on the terrace edges. We herein briefly discuss the selectivity in terms of a mechanism in which the highest occupied and lowest unoccupied molecular orbitals （HOMO and LUMO） of the molecules interact with the surface.

Study on Bending of Woven Fabrics Using Linear Viscoelasticity Theory

The bending behavior of woven fabrics under low curva-ture conditions has been analyzed by linear viscoelastictheory.The fabric is assumed to behave viscoelasticallyand to be subjected to frictional restraints in bending de-formation.The frictional restraint is considered to beproportional to the curvature and can be described by africtional moment.A model has been constructed by astandard three-element solid model and a paralleledfrictional sliding element.The equations of the model fora cyclic curvature variation are derived.A set of param-eters of the equations for each fabric has been obtainedexperimentally.Predictions of the bending rigidity andhysteresis for wool,cashmere,wool/polyester blended,polyester and cotton fabrics are made,displaying verygood agreement with the experimental observations.

Research on Properties of Woven Fabrics Treated by High Pressure Water Jet

The paper introduces a new technique for the treatment of the woven fabrics. Sprayed by high pressure water jet, the appearance, handle and stiffness of the fabric are improved. Other properties of the high pressure water treated fabrics like drape coefficient, air permeability, tenacity are also presented.

VARIATION OF WOVEN FABRIC GEOMETRY——Non-uniform Flattening of Yarns

In previous research much effort has been devoted to the geometry of woven fabrics and relat-ed problems under the assumption of constant yarn configuration in fabric.This paper will first re-port that image crimp (yarn crimp measured by an image analysis method) seems larger than actualvalue.From the explanation of this result,the variation of yarn configuration in woven fabric dueto the non-uniform flattening is revealed.The significance of this actual structure of woven fabricsis discussed.It is believed that the variation of yarn configuration is very important for fabric per-formance,and may be an advantage for fabric quality.

NONLINEAR MICRO-MECHANICAL MODEL FOR PLAIN WOVEN FABRIC

The warp yarns and weft yarns of plain woven fabric which,being the principal axes of material of fabric,are orthogonal in the original configuration,but are obliquely crossed in the deformed configuration in general.The orthotropic constitutive model is unsuitable for fabric.In the oblique principal axes system the relations between loaded stress vectors and stress tensor are investigated,the stress fields of micro-weaving structures of fabric due to pure shear are carefully studied and,finally,a nonlinear micro-mechanical model for plain woven fabric is proposed.This model can accurately describe the nonlinear mechanical behavior of fabric observed m experimeuts.Under the assumption of small deformation and linearity of mechanical properties of fabric the model will degenerate into the existing linear model.

Principle and Method for Structural Design of Digital Woven Fabric

Digital woven textiles are one of the latest research areas of digital textiles. The key of research on design of digital woven fabrics lies in structural design. Nowadays, the application of digital design technology has fundamentally changed the concept of structural design of woven fabric, giving rise to design methods and effects that were deemed impossible before. A study has been carried out to analyze the nature of woven structures and the methods of structural design. This paper proposes an innovative principle and method of structural design under digital design concept, on which the design of digital gamut weaves and establishment of weave-database were presented to meet the requirement of balanced interlacement. It is envisaged that the results of this study will enhance future research in creation of digital woven fabrics, with particular emphasis on digital jacquard fabrics. Meanwhile, this study is also laid the foundation for the intelligent design of woven textile.

Factors Influencing Anti-ultraviolet Performance of Undyed-woven Fabrics

Main factors influencing anti-ultraviolet performance of woven fabrics are investigated. By means of detailed arrangement of sample design, sample making, testing and analyzing, it shows that fiber materials, fabric compactness, fabric weave and yarn type are the four important factors influencing anti-UV performance of woven fabric, but with different effects. Among them fiber material is the most important factor. For the common fiber materials used, it shows that the anti-UV performance of polyester is comparatively better than others. Once fiber material is determined, fabric with medium float weave and high compactness can offer a good anti-UV performance. The anti-UV performance of fabric with ＂anti-UV＂ filament yarn is better than that with ＂anti-UV＂ staple yarn. The anti-UV property of fabrics with untwisted filament yams is better than that with twist counterparts.

Comparative Study of Polypropylene Non-Woven Surgical Mask and Locally Manufactured Woven and Knitted Fabrics Facial Masks

The outbreak of coronavirus has led to an increase in the demand for facemasks globally. Unavailability of appropriate polypropylene non-woven fabrics face masks as a result of inadequate supply to satisfy the growing population has brought about the manufacturing of locally fabrics masks to augment or substitute standard medical class facemasks. The study aims at analyzing airflow of these locally manufactured fabrics to determine possible means of transmitting the virus as well as establish comfort of the user of these masks. Standard polypropylene non-woven, woven and knitted fabrics were considered for the study. Air permeability test was conducted on these fabrics using Frazier Air permeability tester. Depending on the property significant variation in the textile fabrics, polypropylene non-woven is widely accepted for facial masks. Nevertheless, this study illustrates that woven and knitted fabrics have more open structures, which allow a high rate of air penetration and so may require two or three layers to prevent antimicrobial or antiviral potential.

Effect of Twisted Fiber on Flexural Property and Microstructure of Woven Fabric Reinforced Composite

Two kinds of 2.5D deep straight-joint structure ultra-high molecular weight polyethylene（UHMWPE）（twisted and original） fibers woven fabric reinforced epoxy resin composites were prepared by the hand lay-up method. Subsequently, the flexural property, microstructures, and failure mechanisms of the composites were also investigated. The average flexural strength of 2.5D deep bend-joint structure twisted fiber and original fiber woven fabric composites were 176.66 MPa and 204.45 MPa, respectively. The results of the characteristics indicated that the twist was the main factor which affected the flexural performance. Flexural property vitally relied on the strength of the fiber itself. Twist decreased the strength of the yarns, which meant that when the mechanical property of woven fabric reinforced composites was improved, the yarns must be kept straight in the woven fabric. The study are extremely valuable to guide the improvement of the mechanical property of the woven fabric reinforced composites.

Theoretical and Experimental Analyses of Poisson Ratios for Plain-Woven Fabrics

A theoretical model with extensible yarns for plain-woven fabrics is developed to determine the calculation of Poisson ratios.The stress ratio( warp: weft),as one of parameters corresponding to Poisson ratio variations, is introduced to complement the theoretical model. To evaluate the reliability of the theoretical analysis,a series of biaxial tensile tests of a plain-woven fabric with nine stress ratios are conducted carefully,and the theoretical results are compared with the experimentally measured values. The effects of other influencing factors, including geometric and mechanical parameters of yarns,on Poisson ratios are analyzed thoroughly.This solution method could be applied without difficulty to estimations of Poisson ratios and realistic designs for plain-woven fabrics.

BUCKLING ANALYSIS OF WOVEN FABRIC UNDER UNIAXIAL TENSION IN ARBITRARY DIRECTION

The buckling of a fabric sheet subjected to a uniaxial tension in a direction making arbitrary angle, theta (0degrees < theta < 90degrees) say, with respect to that of warp is investigated. The equation to determine the buckling direction angle, beta say, was obtained and, as illustration, the solution curves of the equation for theta = 45degrees and theta = 30degrees were plotted. It is shown that when the fabric sheet is subjected to tension in non-warp/non-weft direction the out-of-plane buckling of fabric is possible, two buckling modes (flexural and extensional modes) and the both corresponding buckling conditions are obtained. The results given by ZHANG and FU (2001) are the special cases of this paper.

MODELLING OF TENSILE STRESS-STRAIN CURVE OF WOVEN FABRICS

A general shape of tensile stress-strain curves of woven fabrics is first recognised by puttingtested and predicted results together.An exponential function with two parameters is then selectedfor the prediction of tensile stress-strain relationship.The predicted results by using the proposedfunction show excellent agreement with experimental data.

Analysis of Apparent Elasticity Constants of Woven Fabrics

The woven fabric can be defined as orthogonal elastomer if the extension force that puts on the fabric is very small. Based on the precondition, the apparent elasticity constants of a woven fabric were analyzed theoretically in the paper. The bias angle (which is between weft yarns and extension direction ) affects apparent elasticity modulus and elasticity coefficient of the fabric in the extension direction. And the experiment describes fluxes of elasticity constants going with the bias angle of the fabric.

Investigation on Bending and Creasing of Woven Fabrics under Low Curvature

Under the assumption of semi - circular form for a fabric bend, creasing of fabric strips and compression of fabric loops are analyzed by neglecting the structural complexity of the fabric. The relationship between the creasing force and deformation are deduced using an energy method and solutions are given for a linearly elastic material with constant internal frictional constraint. The agreements between the theoretical predictions and experimental results are very satisfactory.

Auxetic Woven Fabrics—Pores' Parameters Observation

Manufacturing of a macro-scale helix auxetic yarn(HAY)was described. Consequently areal woven fabric and three kinds of woven fabrics various in weaves were introduced respectively. Their expected auxetic effect( assured by double helix yarn) was tested through the Poisson's ratio value(for auxetic structure is negative).Other observed parameters talked about variation in woven fabric porosity and the pores' parameters during the sample straining.Setting of this non-standard test( connection between dynamometer and image analysis) was also introduced. The differences among observed parameters were evaluated and conclusions for three types of woven fabrics were determined. It was found that less auxetic behavior caused less porosity. Less auxetic structure( satin) with longer floating threads embodies bigger pores' size and less circularity. The plain pattern has the greatest porosity but the smallest pores; the satin pattern behaves by contraries.

INCREMENTAL MICRO-MECHANICAL MODEL OF PLAIN WOVEN FABRIC

Warp yarns and weft yarns of plain woven fabric are the principal axes of mate- rial of fabric. They are orthogonal in their original con?guration, but are obliquely crisscross in deformed con?guration in general. In this paper the expressions of incremental components of strain tensor are derived, the non-linear model of woven fabric is linearized physically and its geometric non-linearity survives. The convenience of determining the total deformation is shown by the choice of the coordinate system of the principal axes of the material, with the convergence of the incremental methods illustrated by examples. This incremental model furnishes a basis for numerical simulations of fabric draping and wrinkling based on the micro-mechanical model of fabric.

Geometry effect on mechanical properties of woven fabric composites

The effects of geometry on mechanical properties in woven fabric composites were explored. Two types of composites, including one-layered and two-layered composites, were designed and studied. For one-layered composites, inter-strand gap effects on the mechanical properties were studied, while three cases of geometries with inter-strand gaps in two-layered composites were evaluated. A woven fiber micromechanics analytical model called MESOTEX was employed for theoretical simulation. The predicted results show that the inter-strand gap and simple variation of the strand positions in a repeating unit cell significantly affect the mechanical properties of woven fabric composites.

Novelties Filtration Theory of Liquid Chromatography-Mass Spectrometry in Volume Nanotube of Cotton Filament of Layers Woven Fabrics

Objectives of the research to present a modern theory of water purification for multiple purposes entitled “a novelties filtration theory of liquid chromatography-mass spectrometry” is an exceedingly sensitive and specific analytical technique in volume layers woven fabrics that can precisely determine the identities and quantities of compounds within volume Nanotube of cotton filament of layers woven fabrics. The problems are that the filters in the local and international markets have increased complications in configuration, installation and cost without reaching the efficiency that humanity hopes. Throw materials and methods the chromatography-mass spectrometry in layers woven fabrics, and throw the nanotube of cotton filament for purification of water dyes and smells. Industry, in which mass spectrometry is a convenient, versatile method for characterization and identification of process throw the Nanotube of cotton filament for purification of water dyes and smells. Results came up with a theme “innovations in textiles”, and also, for characterization of fibers and contaminants of the fabrics. Additive manufacturing in layers woven fabrics, are the processes used to synthesize a volume object under computer control with successive material layers that have been used and highlighted. The conclusions has included chromatography-mass spectrometry drop, physico-chemical, biological, combined physical-biological and chemical-biological treatment processes recently being developed to meet Jet-filtration, the strict discharging limits set by ASTM standards. Some important aspects of both qualitative and quantitative data analysis have been described and the power of using mass profiles to enhance selectivity and sensitivity has been demonstrated.