Woven Fabric Analysis (II) Dr. Jimmy Lam Institute of Textiles & Clothing

Agenda Twill Weave Pointed (Waved) Twill Herringbone Twill Diamond Weave Diaper Weave

Twill Weave The twill order of interlacing causes diagonal lines to be formed in the cloth. The weaves are employed for the purpose of ornamentation, to enable a cloth of greater weight, closer setting, and better draping quality to be formed than plain weave. Those twill line which point to right from the left bottom are termed as right hand twill or Z twills. Those point to left from right bottom are termed as left hand twill or S twills. For a balance twill, the distribution in warp floats and weft floats are similar.

Twill Weave (2) In simple twill weaves, may consist only one type of twill line, for example 2/2 right hand twill, 3/1 left hand twill etc. But for fancy one, both types of twill line may be employed. Eg. Herringbone twill, diamond twill. The smallest number of threads on which it is possible to construct a twill is 3. The angle of twill weaves depends on the number of move of the twill lines as well as the ratio of warp and weft in both yarn counts and numbers. If the twilled fabric with its twill lines have an advancing in steps of one hand having a square construction, ie both setts and yarn counts of warp and weft are equal, it gives diagnonals at 45 degree.

Twill Weave (3) The angle of twill weaves depends on the number of move of the twill lines as well as the ratio of warp and weft in both yarn counts and numbers. The relationship between the angle formed by twill and the two sets of factors is: Tan Q=(Twill vertically move / twill horizontally move) x (warp sett ends in cm /weft sett picks in cm)

Twill angles and steps Rate of advancement in steps Ratio y/x Angle of twill (degree) 4 horizontally y/4x 14 3 horizontally y/3x 18 2 horizontally y/2x 27 1 horizontally y/x 45 2 vertically 2y/x 63 3 vertically 3y/x 72 4 vertically 4y/x 76

Balance and unbalance twill Warp face unbalance Z twill Balance Z twill

Balance and unbalance twill (2) Weft face unbalance Z twill Warp face unbalance S twill

Pointed (Waved Twill) They are twill weaves with reversal twill line direction at suitable intervals either across the width or along the length. The basic weaves of which are either a simple weave, 2/2 twill, or a diagonal twill with more than one or serveral different twill lines, e.g. 2/2/3/1 twill.

Point Twill Vertical Point Twill Horizontal Point Twill

Point Twill

Herringbone Twill These twill weaves will reversal direction of twill lines in a different manner as compared to that of waved twill. At the points of reversing take place, lifts of warp ends exactly opposite, change from up to down or down to up.

Herringbone Twill (1) Horizontal Herringbone Twill

Herringbone Twill (2)

Diamond Weaves Simple diamond weaves are based on twill with pointed twill principles. The constructions are based on principles combining horizontal and vertical pointed twill together, and are symmetrical about their vertical and horizontal axis.

Diamond Weave

Diamond Weave (2) Pointed Twill with Horizontal and vertical line

Diaper Weaves Diaper weaves are based on further development of herringbone twill, extend in both directions, i.e. vertically and horizontally, and the whole weave is fall into four quarter by the typical herringbone cut effect.

Diaper Weave Extended Herringbone Weave

Diaper Weave (2)