3.2.5 Angled twills

1. 3.2.5 Angled twills 1. Concept The angled twill is constructed by changing the sign of shift from plus to minus after a given number of threads. (Recalling that reinforced twill is constructed by extending floats; elongated twill by changing the shift; curved twill by using an alternating shift)

2. The appearance of the fabric like an angle, so it is called angled twill. See Fig.3.21. • Angled twill weave can be divided into vertical angled twill and horizontal angled twill.

3. Vertical angled twill • The vertical angled twill has two diagonal lines which are symmetrical about a predetermined warp thread.

4. How to construct vertical angled twill: • First, the size (repeat) of the angle needs to be determined. • RO= • Where KO is the number of warp threads after which the sign of shift changes.

5. 2. Weave drawn: (1) Calculating the repeat: Ro=2Ko-2 Ry=Ryb (2) Drawing the ends from 1 to Ko based on the basic twill (3) Drawing the others based on the changing sign of shift. ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ • Example: construct the angled twill on the base twill ■ ■ ■ ■ ■ ■

6. 3. Weaving plan • Pointed draft is used for the angle twill. ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■

7. 4. Applications • Angled twills are widely used for lady’s fabric, woolen coat, sheet, various tweeds. • Sample: vertical angled twill

8. Applications: Horizontal angled twill

9. Notes: • Short warp or weft floats should be used so as to avoid overlong floats when the weave is reversed. • Vertical angled twill weaves are achieved with point draft. • Horizontal angled twills are achieved with straight draft.

10. 3.2.6 Herringbone and broken twills • Herringbone • Concept • The twill line of herringbone weaves is broken at predetermined intervals to continue in the opposite direction. • Cuts or breaks occur in the fabric where warp floats are exchanged for weft floats and vice versa. • Clean cuts avoid long floats that can occur in angled weaves. • See Fig.3.24. The appearance of the fabric likes herring’s bone, so it is called herringbone.

12. Weave drawn • Herringbone weave construction is similar to angled twill except the repeat calculation. • Example: construct a herringbone weave based on weave twill , KO = 6.

13. Broken twills • Concept Broken twill is formed by a break in the continuation of the twill line at predetermined intervals. See Fig. 3.27

14. Fig.3.27 various broken twills: “●”(lifts) indicates the sequence of the rearranged ends or picks.

15. Construction of broken weave • The broken twill is constructed by changing the sequence of the ends or picks.

16. Weaving plan • Broken draft is suitable for herringbone and broken twills. • Applications • They are used for herringbone tweeds, sheets, and various decorative fabrics.

17. Herringbone weave sample:

18. 3.2.7 Diamond weaves 1. Concept • Diamond designs are based on angled twill and can be considered as vertical angled twill combines with horizontal angled twill. (See Fig. 3.29) Fig.3.29 diamond weave

19. 2. Weave drawn • (1) Choosing base weave: • (2) Determining Ko, Ky: (the size of the pattern) • (3) Drawing the basic part according to base weave and Ko, Ky. • (4) Drawing the angled twill. • (5) Drawing the other part by taking the weft thread Ky as the axes of symmetry.

20. Example: • Drawing the diamond weave, base weave is 2/2↗ twill, KO=4, Ky=4. ◇ ◇ ◇ ◇ ◇ ◇ ◇ ■ ■ ▲ ■ ■ ▲ ▲ ■ ■ ▲ ■ ■

21. Diamond fabric samples:

22. Diaper weaves • Diaper designs are based on herringbone twill combining with a horizontal herringbone twill. See Fig.3.30 Diamond and diaper weaves are suitable for pointed draft and they are widely used for lady`s cloth, sheet and woollen fabrics. Fig.3.30 Diaper weave

23. Homework: 1. Drawing the following angled twills, and adding the weaving plan: 2. Drawing the following Herringbone weaves: 3. Drawing the diamond weave, the basic weave is 2/2↗ ,KO=10, Ky=10