3. 5.1 Dyeing in Coloured Yarn
5.1 Dyeing in Coloured Yarn
• The term package dyeing usually denotes for dyeing
of yarn that has been wound on perforated cores.
• This helps in forcing the dye liquor through the
package.
• With the start of dyeing cycle, the dye liquor goes on
circulating throughout the vessel and tank.
• This happens till all the dye is used up or fully
exhausted.
• The dye flows through to the yarn package with the
help of the deliberate perforations in the tube
package.
• Once full exhaustion is brought about, the carrier of
colored yarn is consequently removed from the vessel.
• A large centrifuge removes excess water from the
packages.
• Finally the yarn is dried using red drying oven.
4. 5.2 Types of Package Dyeing Machines
Types of Package Dyeing
Machines:
1. Vertical Spindle Machines
Vertical spindle machines are
common today.
The packages are press packed onto
the vertical carrier spindles so as to
increase the payload.
It also aids in the dye liquor
circulation and minimising the
liquor to fibre ratio.
Machineries of this sort can operate
at liquor ratios as low as 6:1.
The following Figure shows a typical
package dyeing machine where the
yarn packages are held on multiple
spindles. An overhead crane system
makes yarn carrier to be entered
and removed from the machine
room.
5. 2. Horizontal Spindle
Machines
a. This is an alternative
configuration for the vertical
spindle machine.
b. Dyeing kier is mounted
horizontally and the yarn
carrier is introduced from a
trolley.
c. This arrangement effectively
replaces the need for crane.
d. Horizontal Spindle Machines
has simplified the design of
the dyehouse building.
3. Tube Type Machines
a.Tube type machines have a
series of vertical or horizontal
tubes into which package carriers
get inserted.
b.The tubes that form the
individual dyeing vessels are
linked by common circulation
pumps and pipe work.
c.These type of machines offers
the advantage of flexibility than
the above mentioned types.
d.This is because individual tubes
can easily be blanked off to
change the overall load limit of
the machine.
6. 5.3 Designing Coloured Fabric
Modern looms make possible to design coloured
fabric using coloured warp and weft yarns.
Various coloured patterns can be obtained in fabric
by combining coloured yarns and weave.
The process starting from selection of suitable weaves
and yarns of different colours.
Process conditions of weaving should be taken into
consideration.
The preparation for coloured warp yarn using
weaver’s beam can be prepared in sectional warping
by rearranging the coloured bobbins on the creel.
7. In sectional warping, additional devices are used compared to direct
warping:
warping table
moveable sectional warping beam
The process are the same with direct warping only it’s wind section by
section using sectional warping beam until it’s complete.
The complete sectional warping beam is transferred to the weaver’s
beam or to the sizing beam.
The colored weft yarns require multi-shuttle looms or shuttles loom
equipped with weft patterning devices.
The repeat of weave is also importance to determine the number of
heald shafts to be used on the loom.
The reason is to get a large coloured pattern with a minimum number
of heald shafts.
The repeat of coloured pattern equals the least common multiple of
the weave repeat and the repeat of coloured threads.
If these numbers are prime, the repeat of pattern equals their product.
8.
9.
10. 5.3 The Usage of Coloured Yarn in Coloured Fabric
5.3.1 Construction of Patterns from
A Given Weave and Colour
Repeats
Example 1,
4 shaft sateen / crepe weave (R
= 4).
Warp and weft colour repeats
are equal to 3; 2 red and 1 white
warp threads 1 red and 2 white
weft threads.
The least common multiple of 3
and 4 is 12.
Therefore, the colour pattern
repeat is 12 X 12 to produce a
fabric on 4 shafts.
11. Example 2,
The weave is same but the
colour repeats of warp and
weft threads have been
changed.
The sequence of warp
threads is 1 red and 2 white
thread.
The sequence for weft
threads are 2 red and 1
white threads.
Such a change gives a new
colour but the same size of
12 X 12
12. Example 3,
Honey comb weave
with the repeat of 8.
Weft overlaps are
marked by dots.
Colour repeat of
threads is as large as
24.
The least common
multiple of 8 and 24
is 24.
The colour pattern
constructed is 24 X
24.
Weft colour repeat; 8
white threads, 8 red
thread.
Warp colour repeat;
8 white threads, 8 red
thread.
13.
14. 5.3.2 Selection of Weaves for a Colour Pattern
Begin by obtaining a colour pattern, depends on the colour
repeats of warp and weft threads.
Example:
Take 8 warp and 8 weft threads.
The odd threads are red and the even threads are white.
Colour repeat is 2 for warp and 2 for weft.
The arrangement of coloured warp threads is shown in the
lower horizontal space, and weft threads in the left vertical
space.
Find the colour of all 64 squares, the intersections of warp
and weft threads.
The first square is the intersections of red warp 1 and red
weft 1.
The point of intersection of white warp 2 and red weft 1
can be red or white, depending on the type of overlap (any
colour in this square). This square is marked by a dot.
The intersection of warp 2 and weft 2 can be white only,
because both threads are white.
All 64 squares can be divided into 3 groups: red, white and
square marked by dots.
There are 33 squares marked by dots. Each of these
squares can be painted red or white depends on the
designer. Many different colour patterns can be created.
15. If all the squares with dots are white, the first pattern is created:
16. By painting in red squares, positioned between red squares in vertical
direction, red vertical stripes are obtain:
17. The red horizontal stripes appear on the fabric, while red squares are added in
a similar way in horizontal direction:
18. By painting the dotted squares along the diagonal, zig-zag stripes
running appears either from right to left or from left to right:
19. The dotted squares can be pointed in another manner,
so that we get a pattern with closed contours: