1. Woven Fabric Structure (1) Plain and Twill
Dr. Jimmy Lam
Institute of Textiles & Clothing

2. Learning Objectives What is woven structure?
Fabric properties of plain weave;
Fabric properties of twill weave;

3. Woven Structure
Apart from the fabric density (warp and weft per inch); yarn count; selvedge and fabric weight, woven structure plays an important role in fabric quality.
The manner in which groups of warp yarns are raised by the harness to permit insertion of the weft yarn determines the pattern of weave is called woven structure.
Weave pattern (woven structure) affects the fabric durability and appearance.
There are THREE basic weaves used for the majority of fabrics and they are :1) Plain; 2) Twill and 3) Satin structure

4. 1) Plain Weave

5. Plain Weave Plain weave is the simplest and most used weave.
It found in a wide range of fabrics such as gauze, gingham, taffeta, poplin and canvas.
Plain weave fabrics require only TWO hardness because the weave repeats every two ends (1/1)
Fabric with a plain weave is reversible (face and back are the same), unless one side is chosen as the face by finishing or printing

6. Plain Weave
1/1 plain weave
Plain weave on graph paper

7. Plain Weave Characteristics
Plain weave fabric has firm construction. It wears well and ravels less than other weaves.
It provides a good background for printed and embossed design.
Plain weave tends to wrinkle more than other weaves.
Frequently interlacing of plain weave (50% up and 50% down) does not allow yarns to relieve stress from the bent fibres/yarns.
Plain weave fabric has lower tear strength than others because when tearing a plain weave fabric, the yarn breaks one at a time.

8. Plain Weave Ribbed or Corded Plain weave
The ribbed or corded effect is caused by the variations of plain weave.
The rib may be produced in the warp or weft by alternating fine yarns with coarse yarns; or by single yarns with double yarns.
Warp ribbed fabrics are referred as corded effect
Weft ribbed effect is produced when the weft yarns are thicker than warp weft.

9. Ribbed Plain Fabric
Weft ribbed fabric, coarse weft yarn than warp yarn
Warp ribbed (corded) fabric, coarse warp yarn than weft yarn

10. Plain Weave Basket and Hopsack Weave
Basket weave is made by using groups of two or more warp yarns interlacing as one yarn with groups of two or more weft yarns as one yarn.
It is a decorative weave and most of them are made with low yarns per inch and with low twist yarns to increase the weave effect.
This type of fabrics tends not to be durable and will easily shrink in washing.
Two well-known basket weave structures are hopsack and Oxford. Oxford is 2 x 1 basket weave

11. Plain Weave Derivate: Basket Weave
2 x 2 Basket Weave

12. Plain Weave Derivate: Basket Weave
2 x 2 Basket Weave

13. Plain Weave Derivate: Oxford Cloth
2 x 1 basket weave

14. 2) Twill Weave

15. Twill Weave
A distinct design for the twill weave is it form a diagonal line.
In the right-hand twill, the diagonals run towards to the right.
In the left-hand twill, the lines run towards to the left.
Although there is no advantage of one over the other, the direction of the diagonal line can aid in recognition of the face of the fabric.
Denim, gabardine and chino are well-known twill weave fabrics

16. Twill Weave: Right and left hand twill line

17. Balanced 2/2 Right-hand Twill Weave

18. Warp Face 2/1 Twill Weave

19. Twill Variations Fabric A: 2/2 balanced twill
Fabric B:2/1 warp-faced twill
Fabric C:1/2 weft-faced twill

20. Twill Weave (II)
Twill weaves are named according to the number of hardness required to make the design.
The simplest twill weave is either ½ or 2/1 twill (three-leaf twill)
A 3/1 or 1/3 twill are called four-leaf twill.
Twill weaves are classified as balanced or unbalanced according to the number of warp and weft yarns are visible on the face of fabric.
The balanced twill, e.g. 2/2 shows an equal number of warp and weft yarns in the design.
Other twills are unbalanced (warp or weft face), which produces a more obvious twill line and a more abrasion-resistant surface

21. Twill Weave (III)
The diagonal line of twill fabric can be changed according to design.
In a twill weave, the succeeding warp yarn to the right has the corresponding interlacing one weft yarn higher, the weave is 45 degree right hand twill.
If the corresponding interlacing on the succeeding warp yarn is two weft yarns higher or lower, a 63 degree twill weave is produced.

22. Example of 2/1 right hand twill
Yarn interlacing
Point Paper

23. Degree of Twill Angle

24. Twill Weave (IV)
A fabric with a 45 degree twill weave has 45 degree diagonal line only when the yarns per inch in the warp and the weft are the same.
Usually there are more yarns per inch in the warp, so that most 45 degree twill weaves have diagonals of more than 45 degree.
The steepness of the diagonal can indicate strength and durability in the fabric.

25. Discussion
What is basket weave and why they are normally made by low twist yarns?
Why plain weave is normally used for printed fabric?
What are the fabric characteristics of twill weave? What are balanced and unbalanced twill weaves?

26. Discussion
Other than by dyeing and printing, indicate three ways by which a fabric woven with the plain weave may be given added surface interest.