This presentation discusses the process of dyeing sweaters. It is presented by four students and discusses how sweaters are dyed by adding color to the fibers, yarns and fabrics in a solution containing dyes and chemicals. It then provides examples of different dyes used for sweater dyeing and the recipe for dyeing sweaters. It also describes some of the main machines used for sweater dyeing like paddle dyeing machines and rotary drum dyeing machines. Finally, it lists some sweater dyeing industries in Bangladesh and discusses advantages and disadvantages of sweater dyeing.

1. A Presentation On
Sweater Dyeing

2. Presented by,
• Md. Shohrab Hossain (Student Id; 172216)
• Abu Sayed Rafi (Student Id; 172217)
• S. M. Zaki Mujahid (Student Id; 172219)
• Md. Al-Arafin Kaosad (Student Id; 172220)
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3. • Sweater dyeing is the process of
adding color to the fibers, yarns,
and fabrics of a sweater. This
dyeing is normally done in a
special solution containing dyes
and particular chemical materials.
After dyeing, dye molecules have
uncut chemical bond with fiber
molecules due to temperature &
time.
• Sweater has contributed 11.98% to
overall readymade garment
exports of $30.62 billion.
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4. Figure: From yarn to finished sweater
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5. Some Dye (Color) Used in Sweater
Dyeing
Teal Blue Teal Green
Powder Liquid
1 pkg royal blue ½ cup royal blue
1-½ tsp kelly green 2 tbsp kelly green
Powder Liquid
1-½ pkg kelly green ¾ cup kelly green
1 tbsp. royal blue ¼ cup royal blue
Tiger Lily Violet
Powder Liquid
1 pkg tangerine ½ cup tangerine
1 tbsp petal pink ¼ cup petal pink
Powder Liquid
1 tbsp purple ¼ cup purple
2 tsp fuchsia 2 tbsp. fuchsia
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6. Recipe of Sweater Dyeing
• Detergent
• Soda Ash
• Caustic Soda
• Hydrogen Per Oxide
• Stabilizer
• Temperature
• Processing time
0.5 g/l
2.0 g/l
3 g/l
3 g/l
1.5 g/l
90 °C
40 minute
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7. Process of Sweater Dyeing
(Pretreatment)
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8. Process of Sweater Dyeing
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9. Cont…
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10. Cont….
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enzyme + acetic
acid
temp @50
degree

11. Cont….
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12. Cont….
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13. Cont….
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14. Cont….
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15. Cont….
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16. Sweater Dyeing Machine
• Paddle Dyeing Machine;
• Rotary Drum Dyeing Machine;
• Tumbler Dyeing Machines etc.
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17. Paddle Dyeing Machine
• A process of dyeing textiles in
a machine that gently move
the goods using paddles
similar to a paddle wheel on
a boat.
• This is a slow process, but
there is extremely little
abrasion on the goods.
• Horizontal and lateral are
two types of paddle machine.
• Here temperature can be
increased upto 98 ºC.
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18. Working Principal
• HT Paddle Machines work according to the principle of
horizontal paddle machine, however, the temperature can be
raised up to 140° C. PES particles are preferably dyed on HT
paddles. In paddle machines, the dyeing can be carried out
with 30:1 to 40:1, lower ratios reduces optimum movement of
the goods, lead to unleveled dyeing, crease formation. For
gentleness, the blades of the paddle are either curved or have
rounded edges and the rotating speed of the paddle can be
regulated from 1.5 to 40 rpm. Circulation of the liquor should
be strong enough to prevent goods from sinking to the
bottom. Paddle machines are suitable for dyeing particles of
all substrates in all forms of make ups. The goods are
normally dyed using PP/PET bags.
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19. A Specification of Paddle Dyeing Machine
Manufactured by Jingjiang Huaxia Technology Co., Ltd. (Haifeng)
($ 8500)
• Brand Name: HTAI
• Power(W): 370w
• Dimension(L*W*H): 920*650*1250mm
• Weight: 106kg
• Place of Origin: China
• Voltage: 220V
• Certification: ISO 9001
• Material: Stainless steel
• The diameter of rubber roller: 130mm
• Rubber roller the length: 430mm
• Pressure range: 0-7kg
• Hardness of roller: 72 degree
• Pressure-absorbing rate: 45%-90%
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20. Rotary Drum Dyeing Machines
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• Rotary drum machines are sometimes preferred for garments,
which require gentler handling, such as sweaters.
• These machines work on the principle of “movement of textile
material and a stationary liquor".
• The rotary drum dyeing machine consists of rotating
perforated cylindrical drum , which rotates slowly inside a
vessel of slightly bigger in size. The internal drum is divided
into compartments to ensure rotation of goods with the drum
rotation, and the outer vessel holds the required quantity of
dye liquor. High temperature drum machines are capable of
processing the garments up to 140° C.

21. Figure of Rotary Drum Dyeing Machine
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22. Features of Modern Rotary Dyeing
Equipment
• Lower liquor ratio
• Gentle movement of goods and liquor (minimizes surface abrasion)
• Rapid heating and cooling
• Centrifugal extraction
• Variable drum speed with reversal capability (adaptable to a wide variety of
goods)
• Continuous circulation of goods (improves migration control)
• Easy of sampling
• Variable water levels with overflow rinsing capabilities
• Large diameter feed and discharge lines (minimizes filling and draining
time)
• Microprocessor controls
• Lint filters
• Pressure dyeing
• Auto-balancing drums
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23. A Specification of Rotary Drum Dyeing
Machine
Manufactured by Nantong East Heptanoic Machinery Co., Ltd
(Shuangfa) ($100000 - $120000)
• Power(W): 7.5kw
• Dimension(L*W*H): 1040*730*1500mm
• Weight: 600kg
• Place of Origin: Jiangsu, China
• Brand Name: Donggeng
• Voltage: 380V
• Certification: Chinese Certificate
• Material: Stainless Steel
• Working Temperature: 140-145 ° C
• working pressure: .75x105Pa
• Low Liquor Ratio: 1:6 - 1:8
• Capacity: 15~2000kg
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24. Tumbler Dyeing Machine
• These machines are being used for
small garments either in loose form
or in open mesh bags.
• Design wise the tumbler dyeing
machines are similar to the
commercial laundering machines.
• The principle of operation is to load
the material into perforated inner SS
tanks , which rotates round a
horizontal shaft fixed at the back of
the drum. The drum is divided into
compartments for moving the goods
with rotation of drum.
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25. Some Sweater Dyeing Industries in
Bangladesh
• Galaxy Sweaters & Yarn Dyeing Ltd., Uttara, Dhaka
• DBL Group, Gulshan, Dhaka.
• Maa Knitting & Dyeing Industries Ltd., 39, Siddeshwari, Dhaka
• Golden Times Sweater & Dyeing Ltd.
• Far East Knitting & Dyeing Industries Ltd., Gazipur
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26. Advantages
• Handling of smaller lots economically.
• Enables various special effects to achieved.
• Distressed look can be effectively imparted.
• Unsold light shades can be converted into medium and deep shades.
• By the time the garment has been in a boiling dye bath and then
tumble-dried, it will have adopted its lowest energy state and will
not suffer further shrinkage under consumer washing conditions.
• Latest fashion trends can be effectively incorporated through
garment wet processing by immediate feedback from the customer.
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27. Disadvantages
• High cost of processing
• A little complicated dyeing
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