Woven Fabrics - Fairchild Books

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Most twills are either warp face or balanced. (See Figure 5.11a–c.) This produces a more obvious twill line and also a more abrasion-resistant surface. In a twill weave, every warp yarn interlaces in the same order, which may be 2 — 1 , 2 — 3 , 3 — 2 , or any other sequence. However, each succeeding warp yarn starts the sequence of one or more filling yarns higher or one or more filling yarns lower. If each succeeding warp yarn to the right has the corresponding interlacing one filling yarn higher, the weave is a 45° right-hand twill (see Figure 5.12a and b). If each succeeding warp yarn to the right has a corresponding interlacing one filling yarn lower, the weave is a 45° left-hand twill. The step can also be more than one. If the corresponding interlacing on the succeeding warp yarn is two filling yarns higher or lower, a 63° twill weave is produced. Stepping up or down three filling yarns produces a 70° twill, up or down four produces a 75° twill. Most twills are 45° twills but the difference in yarn size of the warp (finer) and the filling (coarser) may cause the perception of a 63° twill (i.e., steeper twill line). A twill weave with a diagonal line greater than 45° is also referred to as a steep twill. If the diagonal line is less than 45°, it is sometimes referred to as a reclined twill. Figure 5.13 shows the different twill angles. Important Features Twill lines can be made more prominent by using plied yarns, high-twist yarns, twill weaves with longer floats, high yarns per inch, and yarn twist opposite to the twillline direction. <strong>Fabrics</strong> with these prominent lines (e.g., gabardine) may become flattened by wear and pressure, and thus become shiny. Twills are widely used for work clothes (e.g., denim), suiting fabrics (e.g., serge), and dress fabrics (e.g., surah). Twill weaves have fewer interlacings than plain weave, which permits more yarns per inch in the fabric and makes twills more compact, stronger, heavier, and more durable than plain- and basket-weave fabrics. In twill, the floats are short, so yarn snagging is not a problem. Broken-Twill Weave Although the twill lines usually run in one direction, sometimes a fabric combines right- and left-hand twills. This weave is called a broken-twill weave. It is made from a regular twill weave in which the twill runs in one direction (e.g., right) for a desired number of yarns, and then the direction of the twill is reversed (e.g., left) for a desired number of yarns. The pattern then repeats. A well-known broken-twill design is chevron. This design produces stripes in a zig-zag effect. Usually yarns FABRIC SCIENCE A 100 F a b c Figure 5.11 (a) Balanced twill 2 — 2 ; (b) warp-face twill 2 — 1 ; and (c) fillingface twill 1 — 2 . Figure 5.12 (a) 45° right-hand twill weave and (b) 45° right-hand twill on graph paper. a b
75 70 63 45 Figure 5.13 Degree of twill angle. in two different colors are used to accentuate these designs. Herringbone is considered a broken twill by many. It is so called because the vertical stripes of both right- and left-hand twill resemble the backbone of a herring fish. (See Figure 5.14.) Satin Weave 27 20 15 Figure 5.14 Herringbone weave shown on graph paper. In a true satin weave, there is only one interlacing for each warp yarn, and only one interlacing for each filling yarn in each repeat of the weave. Also, no two interlacings ever touch or are adjacent. This means the satin weave fabrics have relatively long floats. WOVEN FABRICS A 101 F One set of yarns forms most of the face; the other set forms most of the back. In a warp-face satin, the face is predominantly warp yarns. A filling-face satin has filling yarns predominant on the face. Thus there are no balanced satins comparable to the balanced twills. (See Figures 5.15a–d.) Satin weaves are designated by the number of harnesses they require in weaving. A satin may be named a five-harness satin, or a five-shaft satin. Five is the lowest possible and also most common number of harnesses for making satin. Some seven-harness and eightharness satins are also produced, but beyond eight is not economical. For a five-harness satin there are only five interlacings in one repeat of the weave. The number of interlacings is the same as the number of harnesses used to produce the weave. The length of the floats in satin is one fewer than the number of harnesses used. The number of harnesses used is also the size of the repeat in the warp and in the filling directions. Satin is also the name of a fabric of satin weave. Satin fabric is made from filament yarns, with the warp yarns predominant on the face. Satin fabrics are smooth and lustrous for a number of reasons: lustrous filament yarns are used; the weave has few interlacings, and thus, long floats; and the face yarns are very fine and closely packed. Since the greatest luster is in the lengthwise direction (the direction of the floats of satin), garments using this fabric are made so this direction is vertical in the garment to maximize the luster. Sateen fabric is a durable cotton fabric usually with a filling-face satin weave. It is not as lustrous as satin fabric because spun yarns are used in it. Because it is also heavier, and is made with thicker yarns, it is not as drapable as satin fabric. In crepe-back satin, the warp yarns are fine and have little or no twist, and the filling yarns are highly twisted. The face of the fabric is almost entirely warp yarns, and the back is almost entirely filling yarns. Because of the high twist, the filling gives the back a crepe, or pebbly, appearance and leaves the face fairly smooth. Satin weaves produce a very even surface because of the many warp or filling floats. (Satins have the minimum number of interlacings, which are widely distributed.) Although the long floats of the yarns provide luster to the satin-weave fabrics, they are also responsible for the poor wearing quality of many of these cloths. The floats cause the yarns to be greatly exposed to abrasive forces. Also, with filament yarns common in these fabrics, the floats catch on rough surfaces and the filaments break. Thus, satin-weave fabrics are most common in
Page 2 and 3: j.j. pizzuto’s FABRIC SCIENCE ten
Page 4 and 5: Executive Editor: Olga T. Kontzias
Page 6 and 7: Preface xv Acknowledgments xvii 1 T
Page 8 and 9: Secondary Manufactured Fibers for C
Page 10 and 11: 7 Other Types of Textiles 147 Objec
Page 12 and 13: Nonhazardous 224 Recycling 224 Work
Page 14 and 15: Fabric Performance Testing 316 Text
Page 17 and 18: air-jet bare elastic yarn blended y
Page 19 and 20: Identifying Spun and Filament Yarns
Page 21 and 22: Uses of Spun and Filament Yarns Som
Page 23 and 24: Fabrics made from worsted yarn are
Page 25 and 26: this system, one end of a fiber is
Page 27 and 28: textured yarn a b heater c d high p
Page 29 and 30: Table 4.1 Comparison oF sTreTCh Yar
Page 31 and 32: warp yarn Figure 4.14 Making chenil
Page 33 and 34: Table 4.2 Yarn number Conversions W
Page 35 and 36: Table 4.4 Thread Finishes and Their
Page 37: FABRIC SCIENCE / Swatch Kit Assignm
Page 40 and 41: Over 4,000 years ago, man created f
Page 42 and 43: yarn package yarn package yarn pack
Page 44 and 45: Figure 5.5 Various types of selvage
Page 46 and 47: the same appearance as when the fab
Page 48 and 49: More fabrics are made with plain we
Page 52 and 53: Figure 5.15 (a) Five-shaft warp-fac
Page 54 and 55: Figure 5.18 Filling-pile weave fabr
Page 56 and 57: Sometimes the pile loops are cut in
Page 58 and 59: light-pattern changes to create a r
Page 60 and 61: A product that can be considered as
Page 62 and 63: Glossary of Classic Woven Fabrics A
Page 64 and 65: Frieze: Heavy, thick, rough-surface
Page 66 and 67: Taffeta: Medium-weight, plain-weave

Woven Fabrics - Fairchild Books

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