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Zero Liquid Discharge
Published in Ashok K. Rathoure, Zero Waste, 2019
Ashok K. Rathoure, Tinkal Patel, Devyani Bagrecha
The case study of a textile unit (weaving of grey cloth) at Om Textile Park, Kamrej Surat (Gujrat) India has been considered. They are manufacturing the grey cloth from yarn which is available from the local market. Knitting is a technique to turn thread or yarn into a piece of cloth. Knitted fabric consists of horizontal parallel courses of yarn, which is different from woven cloth. The courses of threads or yarn are joined to each other by interlocking loops in which a short loop of one course of yarn or thread is wrapped over another course. There are two types of knitting:Weft knittingWarp knitting.Weft knitting is a method of forming a fabric in which the loops are made in a horizontal way from a single yarn and intermeshing of loops take place in a circular or flat form on a cross-wise basis. Warp knitting is a method of forming a fabric in which the loops are made in a vertical way along the length of the fabric from each warp yarns and intermeshing of loops take place in a flat form of length-wise basis. Weaving is a method of textile production in which two distinct sets of yarns or threads are interlaced at right angles to form a fabric or cloth. Other methods are knitting, crocheting, felting, and braiding and plaiting. The longitudinal threads are called the warp and the lateral threads are the weft or filling.
Non-linear multi-scale modeling of 3D-spacer-rubber composites
Published in Bertrand Huneau, Jean-Benoit Le Cam, Yann Marco, Erwan Verron, Constitutive Models for Rubber XI, 2019
D. Aranda-Iglesias, G. Giunta, S. Belouettar, A. Peronnet-Paquin, F. Sportelli, D. Keniray
Computerized weft and warp knitting machines have made possible to develop three-dimensional (3D) textiles with improved physical, thermal and mechanical properties (Spencer2001). These textiles are widely used as advanced structures in the aerospace, automobile, geotechnical, marine and medical industries (see, e.g., Hu 2008). Within this family of textiles we find the so-called knitted 3D-spacer fabrics, which consist of two independent layers (also called skins) connected but kept apart by the so-called spacer yarns. This kind of textiles can be manufactured by weft or warp knitting, being the latter technique the most commonly used. During a knitting cycle, the top and bottom layers are knitted at the same time using a double-needle bar Raschel machine. Whereas multifilament yarns are always used to knit the outer layers, the spacer yarns are mainly chosen to be monofilaments. Thus, the spacer yarns are also referred to as spacer monofilaments (or piles) in the literature. For a more elaborative and inclusive discussion on the 3D-knitting technology and the different types of fabrics, the reader is referred to Chen (2015), Hu (2008) and Spencer (2001).
Warp-Knitted Fabrics
Published in Tom Cassidy, Parikshit Goswami, Textile and Clothing Design Technology, 2017
Sadhan Chandra Ray, Mirela Blaga
In warp knitting, fabric is made by forming loops from yarns coming in parallel sheet form, which run in the direction of fabric formation (such as the warp in weaving). Large numbers of yarns in parallel sheet form are supplied from warp beams. Hence, warping is essential in warp knitting. Warp-knitting machines are flat and the needles fitted on the needle bar make the loops to simultaneously use the yarns coming from a number of beams through a large number of guides fitted on a number of guide bars [1–4]. The more is the number of guide bars, the more will be the scope of producing diversified warp-knitted structures, as relative order of movements (swinging and shogging) of the guide bars in successive knitting cycles is the key parameter in deciding the structure of the fabric. The movements of guide bars are traditionally controlled mechanically but electronic control devices are very common in modern machines. A few of the popular warp-knitted structures are locknit, sharkskin, queenscord, double atlas, velour, and so on. Locknit is the largest product of warp knitting and is popular in the United States as a jersey knit (Figure 9.1).
Mesh modeling and simulation for three-dimensional warp-knitted tubular fabrics
Published in The Journal of The Textile Institute, 2022
Haisang Liu, Gaoming Jiang, Zhijia Dong
The warp-knitted tubular fabric, a fully formed structure generated by interworking of a double-needle bed warp knitting machine, is widely used in the modern textile industry and medical science such as artificial blood vessels, medical bandages, ropes and net bags and so on (Chen & Shen,1995; Ma et al., 2014; Zhang et al., 2014). In the past many scholars have carried out simulated studies on double-needle bed warp-knitted fabrics which were mainly devoted to the topology structure of loops and most of them were expressed on the basis of flat fabrics (Jiang et al., 2011; Xia & Jiang, 2003; Xia et al., 2006). The tubular fabric is flat with two planes superimposed after knitting. It is difficult to represent a hollow structure during the design process. Distinguished from the plain structure, the tubular warp-knitted products in industrial and medical fields usually present three-dimensional shapes when they are used. So it would be better to simulate the three-dimensional spatial structure to express the usage state. In this way, some key parameters such as lapping notation, fabric density, threading, pattern width, pattern height, yarn count and yarn colors can be promoted more precisely, which are the influence factors of the visual effect, use demand and fabric property including the fabric pattern, mesh size, etc. Three-dimensional effects are instrumental in a fast and convenient design process. The application of computer-aided programs that are compatible with design and simulation has achieved certain results. However, shape simulation of fully formed tubular warp-knitted fabrics is worthy of further study in future research.
The effects of chitosan antimicrobial treatments on the physical and mechanical properties and wear performances of highly elastic fabrics used for burn scar management
Published in The Journal of The Textile Institute, 2018
In warp knitting forms fabric by interlacing loops of yarn, but vertically down the length of the fabric in contrast to weft knitting. Each needle in the knitting width must be fed by at least one yarn and in line with the direction of fabric production. It is the fastest method of fabric production using mainly continuous filament yarns. Locknit is the most popular two-bar structure. The longer underlaps of the front guide bar plate on the technical back of the fabric and the lapping movements are shown in Figure 2 which improves the fabric extensibility, cover and handle, so that the structure is ideal for use as an apparel fabric.
Textiles in architectural acoustic conditioning: a review
Published in The Journal of The Textile Institute, 2022
M. Pilar Segura Alcaraz, Marilés Bonet-Aracil, Ernesto Julià Sanchís, Jorge G. Segura Alcaraz, Ignacio Montava Seguí
In the field of textile technical applications, warp knitting technology has advantages like the possibility to obtain numerous layers of different materials in a single fabric, great dimensional stability and different possible thicknesses, as well as the production of multiaxial fabrics.