3.2.10 Rearranged Twills

1. Concept Rearranging a weave means taking single thread or groups of threads from the base weave and rearranging them in a different order. See Fig. 3.36

Base twill

Fig. b:

Fig. a:

Fig .a : the picks are rearranged in groups of two in sateen

Fig .b :a different rearrangement in warp direction in groups of two

2. They are constructed as follows:

a) Select base weave. b) Determine a plan for rearrangement. c) Rearrange threads: ends or picks.

3. Example: Base twill the new order of warp

threads is 7,8; 5,6; 3,4; 1,2.

Base twill rearranged twill in the given order

4. Applications

Many characteristic fabrics can be made by using rearranged twills due to its versatility.

3.2.11 Shaded twill

1. Concept The shaded twill represents a gradual transition

from the twill with weft effect to warp effect, and vice versa. It is used mostly in Jacquard weaving for large-pattern fabrics. See Fig.3.37

Fabric sample:

2. Weave drawn

Formulae to calculate the repeats:

Ro = Rob (Rob-1 )

Ry = Ryb

Where: Ro---new weave repeat; Rob---the base weave repeat.

3.3 Satin/Sateen weaves Derivatives

1. Reinforced sateen

It is constructed by using the original sateen as the base and adding overlaps. See Fig. 3.38

Adding a warp float at the right of the original one

Example

Fig. 3.39 shows a 11/8 reinforced sateen which is often used for worsted fabric called satin back gabardine.

The face of the fabric has a twill appearance and back has a satin appearance.

2. Shaded sateen

Like the shaded twill, the shaded satin represents a gradual transition from the sateen with weft effect to the satin with warp effect, and vice versa. See Fig.3.40

Ry=Ryb=5RO=Rob(Rob-1)=5×4=20

3. Rearranged sateen/satin weaves

It can be constructed by rearranging the sequence of the picks or varying the shift. See Fig. 3.41, 3.42.

Obtained from varying the shift

Shifts (Sy)=4,3,2,2,3

Obtained from rearranging the sequence of the picks

Home work:

1. Base weave , the order of warp ↗

threads is 1,2, 7,8, 13,14, 5,6, 11,12, 3,4, 9,10, draw the rearranged twills.

2. draw a shaded twill from 1/3 to 3/1 .↗ ↗

Chapter Three Summary:

Derivatives of Elementary Weaves 3.1 Plain weave derivatives. 1. Rib weaves

Warp rib weaves; Weft rib weaves 2. Hopsack weaves

3.2 Twill weave derivatives 1. Reinforced twill 2. Compound twills 3. Elongated twills 4. Curved twills 5. Angled twills 6. Herringbone and broken twills 7. Diamond and Diaper 8. Zigzag Weaves 9. Entwined Twills 10. Rearranged Twills 11. Shaded twill

3.3 Satin/Sateen weaves Derivatives 1. Reinforced sateen 2. Shaded sateen 3. Rearranged sateen/satin