3D Modeling and Simulation of Fancy Fabrics in Weft Knitting

Weft knitted fancy fabrics are widely used in knitted garment design. Due to the complexity of the structures, their modeling and simulation needs to be solved in three-dimensional (3D) CAD developments. In this paper, 3D loop geometrical models of weft knitted fancy structures, including tuck stitch, jacquard stitch, transfer stitch and fleecy stitch, were developed based on an improved model of plain loop, and their central axes as some 3D space curves were achieved by using Non-Uniform Rational B-Splines (NURBS). The 3D visual simulation programme was written in C++ programming language using OpenGL, which was a function library of 3D graphics. Some examples of weft knitted fancy fabrics were generated and practical application of 3D simulation was discussed.

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.

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.

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.

Three-Dimension Parametric Simulation of Knitted Fabric Based on the Twisted Loop Model

To enhance the realistic simulation effect of knitted fabric,a new three-dimension( 3D) twisted loop model was proposed. This model was constructed by using Non-uniform Rational B-Spline( NURBS) surface. The control points of this surface were generated through rotating the cross-section along the center path of yarn. The cross-section of yarn was generated based on the two-level hexagonal close packing model. Both of the center path and the cross-section were fitted by NURBS. With this twisted loop model,3D parametric simulation of knitted fabric was realized in 3DS MAX by utilizing MAXScript and analyzing the relationships between structure parameters( including the wale-spacing, the course-spacing,the yarn diameter,and the fabric thickness) and geometric model. The simulation of knitted fabric has 3D realistic twist effect clearly. Furthermore,the structure parameters and the twist parameters of fabric can be modified interactively.

Effect of Elastane on Physical Properties of 1×1 Knit Rib Fabrics

Because of wearing and washing the knit rib fabrics are highly vulnerable to lose their dimensional stability.The work investigated the physical properties of 1×1 knit rib fabrics with or without elastane.The fabrics made from 100%cotton yarn were compared with the fabrics made from cotton/elastane(95%/5%)blended yarns by Lisky circular knitting machine.Pilling,shrinkage,spirality,and bursting strength were tested by the ICI pilling test box,Wascator,and TruBurst machine to demonstrate the effect of elastane on fabric properties.Experimental results showed that elastane has a noteworthy impact on the physical properties of 1×1 knit rib fabrics which can make the fabrics more durable and dimensionally stable in practice.

Analysis of Various Types Engineering Stripe Knit Fabrics of Bangladeshi Knit Industry

This experiment is generally based on the three types of engineering stripe fabrics named single jersey, full feeder lycra single jersey, and single lacoste fabric. In Bangladesh, conventional practices of engineering stripe fabric hardly seen. As the textile engineer, we focused to identify the basic difference between these fabrics. We kept the repeat length constant for all three fabrics. In these circumstances, how stitch length, yarn count, gsm, fabric dia, machine settings, machine maintenance, machine rpm varies into those three mentioned fabrics. It is the main motto of these experiments to make them more favourable into the trendy fashion world.

Investigation of Warp and Weft Knitted Fabric Acoustic Structures Derived from Garment Waste

The mechanical performance of knitted fabric was significantly affected by loop density and geometries. Knitted fabric composites occupy a special position in the field of engineering materials because of their easy to form complex components and high impact energy absorption. But Knitted fabric composites have low in-plane tensile strength because the yarns are in a loop structure in the materials. Sound insulation requirements in automobiles, manufacturing environments, and equipment, generating higher sound pressure drive the need to develop more efficient and economical ways of producing sound absorption materials. The knitted fabric based acoustic materials were produced from cut wastes from different garment industries for their sound absorption property test as per the method described in ASTM E 1050. The acoustic performance of knitted fabrics was measured by independent tube methods for sound waves of 1000-6000 Hz. It is observed that the knitted fabrics acoustic materials prepared from waste materials showed high sound absorption than woven fabrics made from the same synthetic fibers. Moreover, the test revealed that blended knitted fabric had a better sound absorption property.

Effect of Aramid/Carbon Hybrid on the Tensile Properties of Multilayered Biaxial Weft Knitted Fabric Reinforced Composites

The effects of aramid/carbon on tensile properties of multilayered biaxial weft knitted( MBWK) fabric reinforced composites are analyzed by experiments. The tensile tests are inducted by the SHIMADZU AG-250 KNE universal material testing machine and Aramis V6 digital image correlation( DIC) technique.More specifically,the composite samples own four hybrid ratios(Na∶ Nc= 12∶ 0,8 ∶ 4,6 ∶ 6 and 4 ∶ 8). The results showed that the aramid/carbon hybrid MBWK fabric reinforced composites showed nearly linear response until reaching the maximum load and the inserting yarns distribution on the surface of MBWK fabrics reinforced composites had a great influence on the strain pattern distribution. Besides,the tensile strength,the tensile modulus and the elongation at breakage of 0° samples and 90° samples increased with the decreasing of aramid/carbon hybrid ratio. In a word,the changes of tensile strength, tensile modulus and elongation at breakage have a lot to do with the difference of aramid/carbon hybrid ratio.

Washing Range after Printing for Knitted fabric from Goller

Goller Textilmaschinen GmbH, the leading manufacturer of wet finishing ranges for textile industry and also a Member of the Fong’s Group, presented new technology and equipments to the public at Shanghai

Application of Knitted Fabrics in Technical and Medical Textiles

Knitted fabrics and knitting technology play very important role on the fields of technical and medical textiles and their importance is ever greater. Experts estimate that their annual consumption is increasing by 3,8 % in average and it can reach about 24 million tons in 2010. Within this the consumption of each sector is increasing. Roughly one third of the world’s fibre consumption is used for production of technical textiles.The term "technical textiles" covers many fields of application that are mirrored in the terminology of Techtextil which is very much used generally when grouping these products. Techtextil differentiates 11 groups and knitted fabrics and products made by knitting technologies can be found in each of them.The lecture introduces such applications on many examples. We think that use of knitting technologies in the development of technical and medical textiles can help this sector to survive this difficult period of the European textile industry.

Antimicrobial-free knitted fabric as wound dressing and the mechanism of promoting infected wound healing

Fibrous biomaterials are widely used in the design and fabrication of antibacterial wound dressings.Two strategies are used to make anti-infective dressings:antibacterial and probiotic therapies,which have potential biotoxicity and other side-effects.Herein,we report a new strategy for fabricating wound dressings to combat infection.Poly(4-methyl-1-pentene)(PMP) fabric can remove bacteria from infectious wounds through dressing changes based on its efficient bacterial adhesion.The maximum adhered count of S.aureus and E.coli on the PMP fabric was 1.63 × 106CFU/cm~2 and 4.77 × 105CFU/cm~2,respectively.In addition,the PMP fabric could inhibit the twitching motility of bacteria,which is beneficial for inhibiting infection.The ability of the PMP fabric to accelerate wound healing was demonstrated in vivo in a rat wound model.After treatment with the PMP fabric dressing,pathogenic bacteria in the wound were removed through dressing change;therefore,the wound exhibited better healing speed than when the commercial dressing was used.The low bacterial concentration effectively stimulated the expression of growth factors and suppressed wound inflammation,thereby accelerating wound healing.PMP fabric has three advantages:(1) it has been approved for use in clinical treatment by the Food and Drug Administration;(2) no antibacterial agent or probiotics were used;(3) the fabric could be manufactured through an industrial production process.These results indicate that the new strategy can be used in the design of new-generation wound dressings for antibacterial applications.

Automated Density Measurement of Weft Knitted Fabrics Using Backlight Imaging

This paper proposes a new density measurement algorithm to address the issues of poor applicability and inaccurate results associated with the automatic density measurement algorithm for weft-knitted fabrics.The algorithm involves collecting the transmitted light image of the knitted fabric,calculating the tilt angle using the skewing correction algorithm,and rotating the image to correct the weft skew present therein.The pre-rotated and post-rotated images are then projected vertically and horizontally in grayscale,and the obtained projection curves are used to represent the distribution of loops in vertical and horizontal rows.This study proposed a wave peak coordinate verification algorithm that calculates the coursewise densities and walewise densities of the knitted fabric.In experiments,the proposed density measurement method is found to exhibit an accuracy above 98%when compared with the manual mode.

Knitted self-powered sensing textiles for machine learning-assisted sitting posture monitoring and correction

With increasing work pressure in modern society,prolonged sedentary positions with poor sitting postures can cause physical and psychological problems,including obesity,muscular disorders,and myopia.In this paper,we present a self-powered sitting position monitoring vest(SPMV)based on triboelectric nanogenerators(TENGs)to achieve accurate real-time posture recognition through an integrated machine learning algorithm.The SPMV achieves high sensitivity(0.16 mV/Pa),favorable stretchability(10%),good stability(12,000 cycles),and machine washability(10 h)by employing knitted double threads interlaced with conductive fiber and nylon yarn.Utilizing a knitted structure and sensor arrays that are stitched into different parts of the clothing,the SPMV offers a non-invasive method of recognizing different sitting postures,providing feedback,and warning users while enhancing long-term wearing comfortability.It achieves a posture recognition accuracy of 96.6%using the random forest classifier,which is higher than the logistic regression(95.5%)and decision tree(94.3%)classifiers.The TENG-based SPMV offers a reliable solution in the healthcare system for non-invasive and long-term monitoring,promoting the development of triboelectric-based wearable electronics.