A MICRO-MECHANICAL MODEL OF KNITTED FABRIC AND ITS APPLICATION TO THE ANALYSIS OF BUCKLING UNDER TENSION IN WALE DIRECTION:MICRO-MECHANICAL MODEL

The typical micro-knitting structure of knitted fabric,which makes it very different from woven fabric,is described.The tensile tests of knitted fabric are reported.The deformations of the micro-knitting structures are carefully studied.The study indicates that when a knitted fabric sheet is subjected to a tension along w-direction an extra compressive stress field inside loop in c-direction is induced.The extra stress field is also determined through analysis.Finally,a micro-mechanical model of knitted fabric is proposed.This work paves the way for the simulations of buckling modes of a knitted fabric sheet as are observed in experiments.

Tensile Properties of Weft Knitted Fabric Reinforced Composites

Seven kinds of weft knitted fabrics from glass fiber yarns were used as reinforcement to make fabric/epoxy composite laminates. Tensile tests were carried out to examine and compare the mechanical properties in course and wale direction of these composites. On the basis of experimental results, attempts have been made to analyze some main factors influencing stress-strain curve, ultimate tensile strength and initial elastic modulus of specimens.

Investigation on the Dimensional Properties of Relaxed Plain Knitted Fabrics

A geometric model of relaxed plain-nitted fabric isproposed.A method based on the model for predictingthe loop length from the course spacing,wale spacing offabric and the diameter of yarn is deduced,as well as a computer program is developed to graphically represent the structures of plain knitted fabric with various struc-tural parameters.

Wet Permeability and Moisture Vapor Transmission Characteristics of Soybean Knitted Fabrics

Wet permeability of fibrous assembly is mainly influenced by the properties of liquid and the configurations of the fiber which consist of diameter of fiber, twist angle and fiber alignment in a yarn. It can be seen from experimental results that the knitted fabric made of soybean (SB) fiber has goodproperties both in wet permeability and vapor transmission so that the knitting technology and fabric characteristics can be improved.

Finishing Effect on Warmth Property of Cotton/Kapok Blended Knitted Fabric

Nowadays,more and more natural or functional fibers are being investigated due to their utilization in thermal underwear.Kapok fiber is one of the natural cellulosic fibers whose source is the kapok plant. It has hollow body and sealed tail,which exhibits desirable features required for functional textiles of this nature. In this study,cotton / kapok( 80 /20 by mass) blended yarn with two types of yarn size 18. 5 and 14. 8 tex,respectively are knitted into plain stitches. The fabrics are undergone with an optimal preparation plan according to orthogonal design. Then,after dyeing and softening,fabric properties including thermal and water-vapour resistances, wicking property, pilling behaviour, and surface morphology,are tested and scrutinized for their candidacy for thermal underwear. The results showed that cotton / kapok blended fabrics have good thermal resistance which is significantly higher than those of cotton / modal blended fabrics,and the same water vapour resistance compared with cotton / modal blended fabrics which are normally used as underwear. Cotton / modal blended knitted fabrics has better pilling grade than cotton / kapok blended fabrics. Meanwhile, the cotton / kapok blends fabrics have good wicking property. Collectively,it was concluded that cotton / kapok blended fabric was appropriate for thermal underwear. However,the main limitation of these fabrics is their pilling properties.

A micro-mechanical model of knitted fabric and its application to the analysis of buckling under tension in wale direction:buckling analysis

With the aid of the micro-mechanical model of knitted fabric proposed in Part 1 we analyze the buckling of a knitted fabric sheet when it is subjected to a tension along the wale direction. The large deformation of the fabric sheet in the critical configuration is considered and, to avoid possible deviation due to the approximation of the theory of thin plate, the three-dimensional theory of instability is used. The fabric sheet is considered as a three-dimensional body and all boundary conditions are satisfied. It is shown that the buckling of the fabric sheet is possible, two buckling modes and the corresponding buckling conditions are obtained, but only the flexural mode is physically possible as observed in experiments.

Effect of Run - in Ratios on the Mechanical Properties of Two - Guide Bars Warp - Knitted Fabrics

Warp knitting technology gets rapid development at present and becomes one of the most important parts of the textiles.But it is less known how the parameters of warp knitting technology affect the mechanical properties of warp-knitted fabrics.This paper presents discuss a research on the relationships between run-in ratio and mechanical properties of the two-bar warp-knittedfabrics through the measurement and analysis of the mechanical properties of various samples with different run-in ratios.The optimal run一in ratios for the reasonable mechanical properties are obtained from above dis-

Flexural Properties of Weft Knitted Fabric Reinforced Composites

Several different kinds of weft knitted fabrics from glass fiber yarns were used as reinforcement to make fabric/polyester composite laminates. Flexural tests were carried out to examine stress- deflection process and compare the mechanical properties in course and wale directions of these composites. The experimental results indicate that the numbers of load-bearing yarn in course and wale direction and the fabric density are the main factors influencing the ultimate tensile strength and initial elastic modulus of specimens.

Studying the Effect of Polyester Fiber Blend Ratio and Pilling Cycle on Blended Knit Fabrics

Pilling is a severe concern for blended fabrics. The aesthetic look and smoothness are the buyers’ prime requirements. The main focus of the study was to see the pilling behavior from various percentages of polyester fiber blend ratio as well as the different pilling cycles on blended fabrics. The cotton, polyester, and elastane prepared the study fabrics. These fabrics are (90% Cotton/5% Polyester/5% Elastane, 90% Cotton/6% Polyester/4% Elastane, 90% Cotton/7% Polyester/3% Elastane, 90% Cotton/8% Polyester/2% Elastane, and 90% Cotton/9% Polyester/1% Elastane, 85% Cotton/10% Polyester/5% Elastane, 85% Cotton/11% Polyester/4% Elastane, 85% Cotton/12% Polyester/3% Elastane, 85% Cotton/13% Polyester/2% Elastane, and 85% Cotton/ 14% Polyester/1% Elastane, 80% Cotton/15% Polyester/5% Elastane, 80% Cotton/16% Polyester/4% Elastane, 80% Cotton/17% Polyester/3% Elastane, 80% Cotton/18% Polyester/2% Elastane, and 80% Cotton/19% Polyester/1% Elastane). The selected polyester blend ratios were 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18% and 19% respectively. The study used the Martindale pilling tester with 2000, 5000, and 7000 cycles, respectively. The evaluation followed the ISO 12945-2:2000. The study findings are that the polyester fiber blend ratio did not influence the pilling grade on blended fabrics for pilling cycles 2000, and the pilling grade remained constant at 4 - 5. The pilling grade started to deteriorate in pilling cycle 5000 for the fabrics 85%C/10%P/5%E, 85%C/11%P/4%E, 85%C/12%P/3%E, 85%C/ 13%P/2%E, 85%C/14%P/1%E showed the pilling grade 4, and the fabrics made from 80%C/15%P/5%E, 80%C/16%P/4%E, 80%C/17%P/3%E, 80%C/ 18%P/2%E, 80%C/19%P/1%E showed the pilling grade 4, 3, 3, 3, and 3 respectively. For the pilling cycles 7000, the pilling grade further deteriorated for the fabrics 80%C/15%P/5%E, 80%C/16%P/4%E, 80%C/17%P/3%E, 80%C/ 18%P/2%E, 80%C/19%P/1%E showed the pilling grade 3, 3, 2, 2, and 2 respectively. The study finds the dominance of polyester fiber throughout the experiment. The author hopes this study’s outcome will help new researchers, advanced researchers, and the textile industry’s sustainable development research and development team.

Study on How to Design Knitted Fabric Pattern with Mathematical Theory

To improve design capabilities for the knitted fabric pattern,a preliminary study is carried out for the design method.Based on mathematical theory,pattern could be created automatically by computer with inputting different parameters for mathematical functions.The knitted fabric simulation is realized by M1 CAD pattern preparation system of STOLL Company.In the pattern,different color unit is replaced by obverse stitch with different color,or by obverse stitch and reverse stitch with the same color separately,after that the effects of knitted fabrics could be simulated.Designing with this method,it would not only help to acquire a great of diversity patterns,but also improve design efficiency and save cost.

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.

Study on the pre-process technology of knitted fabric made of cotton/vinylon blended hollow yarn by single-factor experiments

以棉／维纶混纺空心纱为研究对象，探讨了针织双罗纹织物在前处理过程中，精练剂浓度、氧漂稳定剂浓度、浴比、Na2SiO3浓度、NaOH浓度、H2O2浓度、煮漂时间、煮漂温度8个因素对针织物白度、毛细效应、顶破强力的关系。实验结果显示：NaOH浓度、H2O2浓度、煮漂时间和煮漂温度是影响织物前处理效果的主要因素，精练剂浓度、氧漂稳定刑浓度、浴比、Na2SiO3浓度对处理结果的影响则相对较小。

Research on the Dyeing Properties of Silk-like Knitted Fabric of Ultra-fine Polyester Fiber

In this paper, dyeing processes of silk-like fabric of ultra-fine polyester fiber are studied through orthogonal experiment, dyeing properties (K/S value, L* value, and C* value) of the fabric are tested under different dyeing conditions (pH value, time, and bath ratlo), and optimum dyeing conditions are arrived at through analysis.

Modeling Locking Angle of the Multi-layered Biaxial Weft Knitted Fabric in Shear Deformation

This paper introduces the construction of the multi-layered biaxial weft knitted fabric （MBWK fabric） and studies the locking angle of this kind of fabric. Moreover, a locking angle model of the MBWK fabric is established for the first time according to its unique construction. Two kinds of locking angles are considered under different restraint conditions: the locking angle θ1 controlled by the inserting yarns and the locking angle θ2 controlled by the stitch yarns. It is concluded that the ultimate value of the locking angle θ is the larger one of the two angles.

Mechanical Properties of Weft-Knitted Spacer Fabrics Integrated with Silica Aerogels

The work investigated surface and mechanical properties of untreated and treated three-layered weftknitted spacer fabrics.In order to optimize the mechanical properties of weft-knitted spacer fabrics,silica aerogels(SAs)coating was employed.Scanning electron microscopy(SEM)images of untreated and treated spacer fabrics were analyzed to ensure the presence of SAs on the coated spacer fabrics.The basic properties of uncoated and coated weftknitted spacer fabrics were studied and compared.Tensile strength and initial modulus were studied according to the GB/T3923 test standard YG026 MB-250 by testing machine.Moreover,compression properties of spacer fabrics were also tested by HD026 G test instrument.In this testing,work of compression,the linearity of compression,recovery work of compression and other parameters were calculated from stress and strain curves.It was found that SAs coating has a significant influence on the mechanical properties of weftknitted spacer fabrics.The statistical analysis also verified the significant performance(P value smaller than 0.05)of treated fabric samples at the 0.05 level.

A STUDY OF FINE DENIER POLYPROPYLENE FIBER KNITTED FABRICS' WET COMFORT——THE WET COMFORT STUDIED BY THE NORMAL OBJECTIVE TEST

Based on the theory of moisture vapor permeability and liquid moisture transmission through fabric, this paper is mainly concerned with the wet comfort of the fine denier polypropylene fiber knitted fabrics. The liquid water transport property the liquid water retention property, the moisture permeability property, the moisture releasing and drying property of these fabrics are tested by normal objective ways and discussed. At last, according to these properties these fabries are classified by grey model synthetic evaluation method.

Study on Wet Permeability Models of Yarns and Knitted Fabrics

Water transport through the pore structure of the knitted fabric can occur only in place where the fiber-water surface attraction force is greater than the water weight in the capillary. To investigate wet permeability of the knitted yarn in the fabric, a liquid transport model is established. The main factors which have significant influences on the liquid transport have been analyzed. It is derived from the argument that the optimal design for the knitted fabric with quick sweat transport property can be obtained.

Influence Factors on the Moisture Transmission of the Pure Polypropylene Knitted Fabrics

This paper analyses the principle of wicking effect of the polypropylene filament yarn. By means of theoretical and experimental analysis, some factors affecting the moisture transmission of the pure polypropylene knitted fabrics are discussed.

Analysis of the Thermohydro - comfort Durability for Microfil - polypropylene Knitted Fabric under Grey System

Thin microfll - polypropylene knitted fabric that is knitted to use new single plated theory on large diameter circular weft knitting machine is a new functional fabric. After military use, the reflective opinions are that it is light, thin, soft, smooth - touch, and it has excellent elasticity, good air perviousness, large water vapor permeability . In this paper, an analysis is held to use grey system theory, and the thermohydro - comfort durability of this microfil - polypropylene knitted fabric is compared with that of common knitted fabrics. The analytical result proves the microfil - polypropylene knitted fabric is satisfactory under the climatic conditions that human body needs to eliminate or retain the quantity of heat. It can be use to seam up not only physical ability training uniform of serviceman but also civil sporty and sportswear et cetera.

Study on Anisotropy and Punching Yield Strength of Knitted Fabrics

In terms of the structural characteristics, knitted fabrics are described as plane orthotropic body with two symmetric axes, and the stress in different direction is approximately linear with strain before the yield point.The punching yield strength can be predicted theoretically by developing a mathematical equation from anisotropic effect of knitted fabrics. The experimental results demonstrate the applicability of theoretical formula. Analyses also reveal that the factors influencing three-dimensional deforming performance can be divided into two categories: fiber-yarn-fabric structural features and deforming condition.