The most obvious way to measure the number of twists per unit length of yarn is simply to untwist a known length of the yarn and check visually to see whether the twist has been completely removed.
The process of drawing the warp yarn through the eye of heald frames according to design is called drafting, and the plan which indicates how drafting needs to be done is called drafting plan. It also denotes the number of heald shaft required for a given weave repeat
Zigzag twill are those in which the direction of twill is frequently reversed at suitable intervals either across the width or along the length. Herringbone twill are those in which the direction of twill is frequently reversed at suitable intervals either across the width or along the length but not as zig-zag twill and weft yarns floating condition is reversed of the previous yarn.
Diamond design is constructed on the principle of zig-zag twill.Pointed draft is used to make diamond design.Diaper design is constructed on the principle of herringbone twill.Straight or broken draft is used to make diamond design.
Classification of twill weave: S twill, Z twill, Warp way twill, Weft way twill, Simple twill, expanded twill, Multiple Twill. Derivarives of twill: Zig-zag, Harringbone, Diamond,Diaper, Broken, Rearranged,Shaded, Steped, Elongated, Combined and Curved twill.
The order of interlacement of warp and weft threads at right angles is known as structure of woven fabrics. The interlooping system of yarns is known as structure for knit fabrics. Classification of woven fabric structure: Simple structure and Compound Structure.Methods of fabric representation:❶Warp overlap in which warp is above weft and ❷Weft overlap in which weft is above warp
Yarn Count Conversion
Conversion from direct to direct system
Conversion from indirect to indirect system
Conversion from direct to indirect system
Conversion from indirect to direct system
Broken twill is formed by breaking the twill line of basic twill. Normally straight draft is used to produce this weave. Rearranged twill is produced by the rearrangement or transposition of the original order of the threads in the regular basic twill.
Normally, when two single yarns are twisted together one should expect some contraction or some increase in length depending on the twisting direction. A contraction will result in a yarn slightly coarser than the estimated value. In order to correct for this difference, typically 5% to 10% contraction or extension should be accounted for.
There are two types of derivatives : Rib and Matt. In rib weave, it produces rib or cord effect in warp/weft direction. Used as grosgrain cloth, mattress cloth,hair cords, blankets etc. Matt is constructed by extending the plain weave both vertically and horizontally. Matt weave finds extensive uses for a great variety of fabrics such as dress materials, shirtings, sail cloth, duck cloth etc.