Twill weave fabric structre

twill weave fabric structure

1. Fabric Structure and Design:
Twill weave
By
Md Vaseem Chavhan
Assistant Professor
VIGNAN University
[email protected]

2. Introduction to twill
1) Concept:
The most characteristic of twill is that they have diagonal lines on the cloth.

3. The basic characteristics of twill weaves are :
(i) They form diagonal lines from one selvedge to
another.
(ii) More ends per unit area and picks per unit area
than plain cloth.
(iii) Less binding points than plain cloth
(iv) Better cover than plain weave
(v) More cloth thickness and mass per unit area.

4. Factors determining the twill
The following factors determine the relative
prominence of twill weaves
(i) Nature of the yarn
(ii) Nature of the weave
(iii) The warp and weft threads/inch, and
(iv) The relative direction of twill and yarn twist

5. Influence of the twist of the yarn
•The twill fabric clearness and prominence of
the twill lines are accentuated if their
direction is opposite to the direction of twist

•If, however, the lines of a twill are require to
show indistinct, the twill should run the same
as the direction of twist.

7. Twill weaves fabrics
•Generally 2/1 twill in Jeans, warp or weft face
boot linings, corset i.e fit garment.
•Generally 2/2 twill in blanket, sheeting
•Generally 3/1 twill in a drill fabric
•Generally 2/2 twill, warp face Gabaridin,
rainproof overcoating
•Generally 3/1 twill in Denim, close fitting
trousers,skirts etc
•etc

8. Designation of twill

2up, 2down; 2- and 2-, 2/2

more convineaintly

9. Relative firmness
•The intersecting of threads gives the cloth firmness, and the
more frequent the intersections are the firmer the cloth is

10. Classification of twill weave

11. The above types of twills are further subclassified as:
(a) Warp face twills
(b) Weft face twills
(c) Warp and weft face twills

The twill weaves are produced in a wide variety of forms. They are however
classified broadly into important categories, namely :
(i) Ordinary or continuous twills
(ii) Zig zag , pointed or wavy twills
(iii) Rearranged twills such as satin/sateen weaves and corkscrew weaves
(iv) Combination twills
(v) Broken twills
(vi) Figured and other related twill weaves

12. Continuous Twill

13. Continuous twill
In these types of twills
the warp thread floats
over all the picks in a
repeat except one pick.
The minimum repeat
size required is 3.
In these weaves the
weft thread floats over
the warp on all picks in a
repeat except one.
In these types of twills
the warp and weft
floats may be equal or
unequal.
Warp faced twill Weft faced twill Balanced & unbalanced twill
2/1, 3/1, 4/1, 5/1 1/2, 1/3, 1/4, 1/5 2/2, 3/3, 4/4, 5/5

14. Zig zag , pointed
or
wavy twills

15. •One of the simplest forms of modified twill is the
waved twill achieved by reversing the direction
of the twill at suitable intervals.

•The reversal can occur either upon a warp
end(horizontal wave), or upon a weft pick
(vertical wave).

•Horizontal effect economically produced in point
draft using few heals on tappets.

•Vertical effect required dobby due to large
number of picks in lifting plan.

16. How to construct vertical angled twill:
• First, the size (repeat) of the angle needs to
be determined.

R
O=

•Where K
O is the number of warp threads
after which the sign of shift changes. 22
O
K

17. 2. Weave drawn: 22
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 Example: construct the angled twill on
the base twill
(1) Calculating the repeat:
R
o=2K
o-2 R
y=R
yb
(2) Drawing the ends from 1 to K
o
based on the basic twill
(3) Drawing the others based on
the changing sign of shift.

18. 3. Weaving plan
•Pointed draft is used for the angle twill.
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19. 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.

21. Herringbone twills

22. • The twill line of herringbone weaves is broken at
predetermined intervals to continue in the opposite
direction (reversal of 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.

24. Weave drawn
• Herringbone weave construction is similar to
angled twill except the repeat calculation.

•Example: construct a herringbone weave based
on weave twill , K
O = 6. 2
2

25. •Owning to principle of opposing, at point of
reversal
•A warp lift with weft lift (and vice-versa)
•Warp face with weft face in reverse direction

26. •Herringbone weave sample:

27. Broken Twill

28. •Broken twill is
formed by a break in
the continuation of
the twill line at
predetermined
intervals.
“●”(lifts) indicates the sequence of the
rearranged ends or picks.

29. C continuous twill
C1 Half broken
C2 frequent breaking
E2 brak size (3) and actual weave size (8)
Total ends= 24
1. Braking and reversing of sequence

30. 2. Enter and Skip (or filling and skip)
•Most suitable number to skip is one less than half
number of threads in repeat
•For 2/2 twill,skip1(4/2 - 1), Fig A,B and C
•For 3/3 twill,skip2(6/2 - 1), Fig D and E

31. •The number of threads in the repeat of
design ascertained by noting position of
weave distant from each other
•Fig F Repeat size of final design is as follows
8(repeat of original twill)/1(downward) x
4(outward) = 32

32. 3.Cut and Join
Small mat or cord effects can be made either to cut
with the twill, or to join it in continuation.

33. Elongated Twill

34. The angle of twill
The angle of twill is the angle between the diagonal twill line
and an imaginary horizontal line or axis parallel to the weft.
This angle is dependent on the ratio between the ends/inch and picks/inch in
the cloth.
When the warp ends/inch is equal to the weft picks/inch, the twill angle
will be 45°.
When the warp ends/inch exceeds the weft picks/inch the twill angle
will be an obtuse angle i.e., >45° (high angle or steep twill).
When the weft picks/inch exceeds the warp ends/inch, the twill angle
will be an acute angle i.e., <45° (low angle or flat twill).

35. 1) The density ratio changes the
fabric appearance. (See Fig.3.14)

36. •Tan α= / = P
o/P
y
•The inclination angle depends on the
density ratio:
• P
o = P
y; tan α= 1; α=45
0

• P
o＜P
y; tan α＜ 1; α< 45
0

• P
o＞P
y; tan α＞ 1; α> 45
0 yp
1 o
p
1
See Fig.3.14

37. 2) The shift changes the fabric appearance.
(1) Calculate the repeats,

Where, R
OB is basic twill repeats.
(2) Draw the first end according to the formula of the basic twill
(3) Draw the other ends according to the same formula, but with the
changed shift

38. 3.Selecting or Rearranging

39. 4. Adding to base mark
In Forgoing methods may result in loose fabric it is preferred
to construct starting with bas line

40. In Steep twill, the warp should be as a rule, show more
prominently on the surface than a weft and vice versa in flat
twill.

Considering reverse convention in figure U and W

41. Combination of twill waves

42. Placing the warp threads of one weaves
among the threads of the other weave.
•Here we can see in Fig.4.8, the ends at B in red are
placed among that of A in black, so crepe weave at C is
produced.
•Notes: More often the ratios of the basic weave repeats are 1:1, otherwise, the
repeats of the crepe weave are the LCM of P
yA &
P
yB and P
OA &P
OB
C
Fig. 4.8

44. Different possible weave by changing Position
•A=B, c.f 6 (6,6),c.m 6
6 possible weave
with(12 X 6)

•J=2I, c.f 4 (8,4), c. m. 8
4 possible weave
with (8 X 16)
,pick wise


•O=O, c.f 8, (8,8), c.m 8
But only 4 possible
weave can
Form with (16 X 8)

45. Combination of flat and Step twills

46. Large fancy twill from small twills
Q(5),R(4),
c.m 20 (5,4)
Possible weave
with(40 X 40).
Bothway

47. Thank You!!!