-->
-->
Twill Weave:
Twill weaves produce diagonal lines on the cloth. In twill weave, the filling yarn interlaces more than one warp yarn (but never more than four, as strength would be sacrificed by doing so). On each successive line, or pick, the filling yarn moves the design one step to the right or to the left, thus forming the diagonal.
Twill fabrics are readily identified by the diagonal lines that the weave creates on the surface of the fabric. Because there are fewer interlacing, the yarns in twill fabrics can be spaced closely together, packed tightly, and held firmly in place. Therefore, twill fabrics are usually strong and durable; they are also supple and drape well. Most twillweave fabrics are made in bottom weight. The compact structure of twill fabrics enables them to shed soil readily, although when soiled they may be difficult to get clean. Depending on their construction, twill fabrics generally show good resistance to abrasion. Twill fabrics are often used for tailored garments, particularly those made of worsted wool yarns.
The simplest twill weave is created by the warp yarn crossing over two filling yarns, then under one, over two, under one, and so on. In the next row, the sequence begins one yarn down. The area in which one yarn crosses over several yarns in the opposite direction is called a float.
The lines created by this pattern are called Wales. When the cloth is held in the position in which it was woven, the Wales (diagonal lines) will be seen to run either from the lower left corner to the upper right corner or from the lower right to the upper left. If the diagonal runs from the lower left to the upper right, the twill is known as a right-hand twilL About 85 percent of all twill-woven fabrics are right-hand twills (American Fabrics 1980, 325). When the twill runs from the lower right to the upper left, the twill is known as a left-hand twilL (See
There are a number of types of twill weaves. All use the same principle of crossing more than one yarn at a regular, even progression. Descriptions of twills may be made in terms of the pattern of warp yarns crossing filling yarns. The description of twill weaves is notated as 2/1, 2/2, 3/2, and so on. The first digit refers to the number of filling yarns crossed over by the warp and the second digit to the number of filling yarns the warp passes under before returning to cross the filling again.
When the crossing is over and under the same number of yarns, the fabric is called an even or even-sided twill. When warps pass over a larger or smaller number of filling yarns than they pass under, the fabric is called an uneven twill
Even Sided Twill weave
The even-sided twill has the same number of warp and filling yarns showing on the face of the fabric. Figure 15.7 shows how such a weave is achieved in a 2/2 twill. Even-sided twills are reversible unless printed or finished or one side.
1. Serge is a popular basic twill fabric made from any number of differentfibers. When serge is made from wool, it is often woven from worsted yarns. Serge will take a crease well, but wool serge tends to become shiny with wear. It tailors well.
2. Flannel, if made of wool, is usually a twill weave with a napped finish.
3. Plaids or tartan patterns are yarn-dyed even-sided twills.
4. In a herringbone twill the direction of the twill reverses itself to form a broken diagonal that appears like a series of V’s: herringbone patterns create a decorative effect. Herringbone twills are common in suiting fabrics.
Filling Faced Twill weave
Filling-faced twills have a predominance of filling yarns on the surface of the fabric. Filling yarns are generally weaker than are warp yarns, so that relatively few filling faced twills are made.
Twill Angles
When the face of a twill fabric is examined, the diagonal of the Wales will be seen to move at a more or less steep angle. The steepness of the angle is dependent on two factors in the construction of the fabric: the number of warps yarns per inch of fabric and the number of steps between movement of yarns when they interlace.
The more warp yarns in the construction, the steeper the angle of the Wales, provided that the number of filling yarns per inch remains the same. This is because the points of interlacing of the yarns will be closer together; thereby the diagonal of the
Wales will make a steep climb upward. When the steepness of the angle is the result of close spacing of warp yarns, these steeper angles are an indication of good strength. If the angle the wale makes with the filling yarn is about 45 degrees, the fabric is a regular twill Fabrics with higher angles are steep twills, and those with smaller angles are reclining twills.Generally, the interlacing of yarns in twill changes with each filling yarn. There are, however, fabrics in which the interlacing of yarns changes only every two filling yarns or every three filling yarns. The less often the interlacing changes, the steeper the angle of the twill will be.In the left hand twill, the diagonals run upward to the left. In the right hand twill, the lines run upward to the right.
Herringbone twill weave
A Herringbone weave has vertical stripes of both right and left hand twills.
Characteristics of Herringbone twill :
• Strong and Durable fabric.
• Twill weaves have fewer interlacing than the plain weave, which permits more yarns per inch in the fabric and makes them more stronger, heavier and more durable than plain, rib and basket weave fabrics. The floats are short, so yarn snagging is not a problem.
• Increased drapablility and resilience than the plain weave.
• Interesting designs
• Ex: Denim, tweed, Jean Right-hand twill weave
No comments:
Post a Comment