Overall process of Denim

1. WELCOME TO
MY
PRESENTATION
ON DENIM MANUFACTURING
Presented to
Shamsuzzaman sheikh
Assistant professor,
Department of T.E,
DUET,Gazipur
Presented by
Soriful islam
S.ID :135057

2. INTRODUCTION
Since the first pair of jeans appeared in America about one and
half century ago, denim wear has gained popularity all over the
world. As a result, jeans wear is one of the most prominent
apparel items in the world apparel market.
Denim fabrics are used as jeans trousers both for men and
ladies. It is extensively used in the world as casual garments,
Shirts, jackets, children wears are also made of denim fabrics.
Its versatility, finds applications in furniture upholstery, bed
covers, curtains, etc. Denim now-a-days is a very
demandable product. To make a denim fabric the required yarn
for the definite construction should be dyed then make a
weavers beam to go to weaving to make fabric.

3. DEFINATION OF DENIM & JEANS
According to Textile terms and definition published by
Textile Institute “ Denim is traditionally a 3/1 warp faced twill fabric made
from yarn dyed warp and undyed weft yarn and Jeans is a 2/1 warp faced
twill fabric used chiefly for overalls or casual wear.”
According to Encyclopedia of Textile Finishing edited by
Prof. Dr. Hans-Karl Rouerre published by Springer “Denim is a firm 2/1 or
3/1 cotton twill-weave fabric with dyed blue warp and raw white weft. The
warp is sometimes dyed during sizing.”

4. HISTORY OF DENIM
Denim at its most basic is a simple cotton fabric – but it has created one of the
most enduring and beloved fashion items in recent history.
The first use of denim as a cotton material dates as far back as the 17th century
when it appeared in upholstery, work pants and awnings, ship’s sails and
cowboy jeans – the fabric of hardworking, honest labour. The origin of its
name is widely believed to be an Anglicism of the French for ‘ serge de Nimes’
– the serge fabric, made in Mines, France.

5. WORLD DENIM MARKET
The world denim market is likely to frow continuously for the next few years.
However, supply is growing at a faster pace.
 World Jeans Market- 51.6 $ Billion in 2007.
 Expected to become 56.2 $ Billion by 2014.
 The gross production of denim fabric is approximately 3,000 million metres
per year.
 Over 50 percent of denim production is based in Asia with Bangladesh, China,
Pakistan, India and Turkey.
 70 Percent of world jeans consumption is in EU, USA and China.

6. TYPE OF DENIM
Demand for fashion variants of classic denim will continue to grow. The most
popular variants are:
 Stone-washed and double stone-washed denims
 Chambrays
 Fancy multi-colour denims
 Denim with metal-effect yarns
 Elastic denins
 Printed denims
 Jacquard-patterned denims
 Denims with fancy yarns

7. TYPES OF DENIM – CONT.
The following denim fabrics with their specific commercial name are widely
produced in the denim industry of Bangladesh.
Normal Fabric = 6 OE * 6 OE / 66 * 35
Ring Fabric = 6, 9, 12 * 7 OE / 66 * 35
Half Cross Fabric = 6 slub * 7 OE / 66 * 35
Cross Latch Fabric = 10 slub * 10 slub / 66 * 35

8. TYPES OF DENIM – CONT.
Some typical denim fabric construction:
Description Wt oz/yd2 Construction: Finished Fabric Design
100%Cotton indigo Half Cross Denim 6 89X55/20RsX16R+16Rs 2/1 RHT
1 00%Cotton indigo Ring OE 8 77X49/13RX12R 2/1 RHT
100%Cotton indigo Vertical Slub 7.25 68X49/1 ORsX20K i2/IRHT
100%Cotton light Indigo Slub Lucky 6.50 79X49/1 6RX14Rs 2/1 RHT
98.5%cotton 1 .5%lycra park indigo stretch
slub
11.50 65X46/7.5RsX8+70D 3/1 RHT
100% Cotton indigo normal 12 10 OE+10 OE*12 OE/69*44 2/1 RHT
100% Cotton indigo 12.10 9 Rs+ 9 R * 7Rs + 7R/ 72 *48 3/1 RHT
100% Cotton indigo 11.65 8 Rs + 9R* 8Rs (MC) / 68 *50 3/1 RHT
100% Cotton indigo 9.8 9 OES+ 9 OE* 10 OE / 75 * 43 2/1 RHT

9. RAW MATERIAL OF
DENIM
MANUFACTURING

10. Fiber
Most of the denims are produced with 100% cotton and cotton-based blends with Lycra®, Polyester, Tencel®,
Bamboo, Jute, Nylon, and Linen etc. An ideal cotton mix for denim should have the following quality
parameters.
2.5% span length > 25mm
Strength (g/tex) >18
Micronaire > 4.5 to 5.0
Maturity Coefficient >0.75
Uniformity Ratio> 49%
Trash> 4.9%
i. 80% waste, which consists of
(i) Dropping-1,
(ii) Dropping-2,
(iii) Flat strip,
(iv) Comber noil.
ii. 20% Fresh Cotton.

11. Denim yarn
The spinning capacity usually determined by in the dye range.For 10 million capacity unit producing 12
ozs average fabric weight with a standard with of 150cms require denim yarn of 16 to 17 ton per day .
Thus spinning of denim yarn is really scale business because of heavy yarn and fabric.
Common yarn size for denim
Warp yarn for bottom weight jeans
 Warp yarn for bottom weight jeans typically range in size from Ne 4.0 to 12.5/1.
 Finer yarns are used lighter weight chambray shirting fabrics,vests,dresses and skirts.
 These yarns may range in count from Ne 12.5 to 30.0

12. Spun yarn characteristics by spinning system
Ring spun Open-end(rotor)
1. Strongest yarn 1. More even
2. Finest yarn 2. Higher strength uniformity
3. Softest yarn 3. Higher production rate
4. “Z” and “S” twist 4. Fewer processes
5. Lowest productivity 5. Lower cost
6. Most unevent 6. Fewer imperfections
7. Most expensive 7. Harsher hand(feel)
8. More hairy 8. Not as strong
9. More torque 9. Limited counts-coarser
10. Widest range of yarn counts 10. “Z” twist only

13. Specialty yarns
Structured denim yarns
 Slub thick place with different lengths.
 Different spacing between slub.
 Variations in the yarn count.
Elastic denim yarns
 The drafted cotton fibers twists around the spandex core
to produce an elastic ring type yarn.

14. Warping section

15. Fig: Unwinding of creel

16. Introduction
Denim dyeing may be achieved in different forms like rope form
sheet form or perforated beam wound form.
Each process required separate preparation process specially the
warping process.
Moreover, sheet dyeing or slasher dyeing can be executed in
different types dyeing machine e.g. continuous combined sheet
dyeing-sizing machine, loop dyeing machine.

17. Warping
Warping is the process of transferring multiple yarns
from individual yarn packages on to a single packages
assembly .
Types of warping in used
1. Beam warping
2. Ball warping (the yarns are brought together and
condensed into a rope before being wound onto a
relatively short cylindrical barrel that has no end
flanges)

18. Warping (cont.)
In ball warping, 250 to 400 yarn ends are pulled from the creel
At interval of every 1000 to 2000 yards (or meters), a lease string is
placed across the sheet of warp yarns to aid yarn separation for the
re-beaming operation,
which will occur later
The yarns go through a funnel- shaped device called a trumpet
which collapse and condense the sheet of yarn into rope form

19. Dyeing and sizing in denim manufacturing
process
Dyeing in denim manufacturing is the most crucial in the
production sequence .
There are three general types of dyeing
1. Rope dyeing range
2. Open warp/ slasher dyeing range
3. Loop dyeing range

20. Fig: Diagram of Slasher Dyeing

21. FLOWCHART OF DYEING & SIZING:
Warper’s Beam

Pretreatment (Scouring) bath

Dryer- wash bath (1, 2, 3)

Color box - 1

Dryer - 1

Color box- 2

Dryer - 2 (Air oxidation is done here)

Color box - 3

Steam box

Color box - 4

Yarn pass between a set of guide roller for oxidation

Color box - 5

22. 
Oxidation

Color box - 6

Guide Roller

Color box - 7

Oxidation

Color box - 8

Oxidation

Wash box (1, 2, 3)

Dryer

Sizing box

Dryer

Accumulator

Leasing

Winding

Weaver’s beam
•Type- Sliding creel
•Arrangement- Two creels are placed parallel to each others.
•Creel capacity-16 warp beams can be placed in each creel.
•Electronic motor is available to slide the creel as well as mount the beams.
Beam creel section:

23. Slasher dyeing vs rope dyeing
criteria Slasher dyeing Rope dyeing
First introduced 1970’s 1915
Required space Less More
mercerising Easy Difficult
Manpower Less More
Broken and repairing Not possible Possible
flexibility Flexible Less flexible
Extra end Extra end No
Different color mixing Not possible Possible
Count mixing Ne 1-30 Ne 1-16
Production capacity Approx. 9 to 11 mill.mt.of
normal capacity
12 ropes=9 to 11.5 mill. Mt.
Cost Less than rope dyeing More than slasher
Yarn quality Higher average

24. FUNCTION OF THE CHEMICALS USED IN SCOURING:
1. Alkali: It converts the oil into water soluble fatty acid & soap.
02. Wetting agent: A soluble or dispersible material that reduces the surface
tension between the material & liquid. Detergency effect helps to clean the
material.
03. Sequestering agent: It reacts with metallic ions & thus makes the metallic
compounds to become a part of complex anion.
DYEING:
Dyeing is consists of 2 dyes. The indigo blue & Sulphur black is used in the
dyeing process of denim. Sometimes brown color is used instead of indigo
blue in the factory according to the requirement of buyer.

25. DYEING RECIPE
For leuco preparation here is a ratio which is followed:
Indigo : 100 g/l
Caustic Soda : 73 g/l
Reducing agent : 93 g/l
Dispersing agent : 0.5 g/l
Sequestering agent : 0.5 g/l
Wetting agent : 0.3 g/l
For leuco preparation here is a ratio which is followed:
Indigo : 100 g/l
Caustic Soda : 73 g/l
Reducing agent : 93 g/l
Dispersing agent : 0.5 g/l
Sequestering agent : 0.5 g/l
Wetting agent : 0.3 g/l

26. Dyeing Process
Dyeing process that is maintained as follows:
 Pure Indigo- Continuous Indigo Dyeing
 Bottoming- Sulphur(Bottom) & Indigo(Topping)
 Topping- Indigo(Bottoming) & Sulphur (Topping)
 Black Denim-Continuous Sulphur Black Dyeing
 Color Denim.

27. Sizing
Sizing is the process in which the threads of a warp are treated with a sizing assistant
in order to increase the wear resistance.
Requirements of sizing
1.Adequate friction resistance and yarn strength
2.Uniform warp yarn tension.
3.Crossing-free yarn passage.
4.Warp splitting/no. of threads.

28. Fig: Beam creel
Capacity of cooking tank: 1000
Ltr
Cooking Temperature: 85º
Cooking time: 25-50 mins
Pick up: 5-10%
Cylinder temperature: 110-130ºc
Squeezing Pressure: By top
roller
Delivery squeeze pressure:
Lowest: 12-17 kN
Highest: 15-20 KN
Stretch: 0.7-1%
Refractro reading: 7-11%
Viscosity: 12-30 sec
Sizing Temperature: 85-90ºc
Sizing BATH:
No of dry cylinders used in this bath = 12
Sizing parameter:

29. Fig: sizing tank

30. The Starch & Softener are used in the sizing bath are given below:
Starch: Emsland E-55 (Modified starch)
Emsland E-14
Softener: Mutton Tallow
Fin Fix
Trefin Wax
Starch:
These are products from grains & tubers. These are mixture of
carbohydrate, oil, nitrogenous substances & mineral matter.
Carbohydrate is a polymer consisting of 25% amylase and 75%
amylopectin. Structurally it is a highly branched glucose polymer.
Starches are cheap & easily available & have proved to valuable
adhesives over a many years especially for cellulosic yarns. This is
manufactured mainly from maize, wheat, rice etc. When starch is
boiled with water, the starch granules swell & break up forming a
smooth & homogenous gelatinous mass.

31. EMSIZE E-14:
Application: Emsize is a starch sizing
agent for spun yarns
Characteristics:
Kind of product: High modified
polymer
Appearance: Off white granules
Moisture content: 9-14%
pH value (5% conc): 9.5-11.5
Viscosity:
Preparation of the solution:
The required quantity of product is added to cold water. Under stirring the slurry should be heated
up till 95ºc and kept for at least 20 minutes at this temperature. Preparation in an autoclave has to be
heated up to 110ºc and kept for at least 10 mins at this temperature.
Both the starch has the following common properties:
excellent sizing effect
transparent flexible film
high adhesion power
compatible with other sizing agents
washed out quickly without enzymes
good biological degradability

33. Introduction
Traditional denim fabric are woven by interlacement of indigo dyed
warp and grey weft.
A variety of denim fabric are made with weave design such as
2/1 twill weave ,broken twill , zig-zag twill, reveres twill,etc.
It also manufactured with fancy design in order to meet the latest
fashion.
Denim fabric normally made of weight range of 3.5 to 16.5 oz per
square yards through 21 oz per square yards has recently developed in
japan

34. The typical reed and picks of some commonly produced fabric is given below;
Construction Finish
EPI
Loom
State
EPI
Finish
PPI
Loom
State
PPI
Finished
Cover Factor
warp
Cover
factor
Weft
Cover
factor
9Rs+9R*7Rs+7R/
72*48
72 68 48 44/45 26.59 24 18.14
8Rs+9R*8Rs(MC)/68
*50
68 63 50 50 26.04 23.33 17.68
8Rs*10Rs+10R/76*5
4
76 71 54 50 27.56 26.87 17.08
9Rs+9OE*12Rs+10+
70D/
78*54
78 64 54 48/49 27.16 26 16.28
8Rs+10R*8Rs+7OE/
72*50
72 71 50 47/48 26 24 17.68
9OEs+9OE*10
OE/75*43
75 68 43 37/39 26.47 25 13.6
10Rs+10OE*6OE+70
D/
76*50
76 71 50 44/45 26.93 24.03 20.41
8Rs+7R+10R*9R/72
*48
72 66 48 41/44 26.69 24.94 16

35. We know,
Cover factor, Kc =( K1 + K2 – K1*K2/28 )
Where, warp Cover factor, K1 = EPI/√ count
And weft Cover factor, K2 = PPI/√ count
Denim fabrics are highly sensitive to the fault incidence. Therefore
maximum care is necessary at all levels to avoid fabric faults.
Normally the loom stoppages are regarded as a serious matter in
accumulating fault level. Loom stoppages in turn depend on a large
extent on the yarn quality. A recommendation based on research
study has suggested the following yarn breakage norms in the
warping and sizing department;

36. Fig: weaving mc (Picanol omni plus 800)

37. Shrinkage %;
Actual Production – Finishing Production / Actual Production * 100
Fig: Front view of a weaving mc

39. Fig: Brushing unit of a finishing mc

40. Fig: Scew roller of a finishing mc

41. Fig: Drying cylinder of a finishing mc

42. Fig: Calendering unit of a finishing mc

43. Fig: Spreading unit of a finishing mc

44. Description of the processes:
Brushing:
The purpose of this process is to remove the lint, fluffs and
loose impurities. This is achieved by subjecting the fabric to kind
of roller beating action.
Singeing:
The objective of this process is to burn out the protruding fibres
from the surface of the fabric. Only blue side singed and it is done
twice.
Softening:
The aim of this process is to modify the feel of denim fabric and to
facilitate the movement of the threads during skewing and shrinkage
process. This is just a softening process where the fabric is passed
continuously through a solution containing 5gm/Htre softener.
Sometimes softener is used as foam form. Use of foam reduces the
quantity of heat required to dry the fabric.

45. CORRECTION OF SKEWING:
The 3/1 twill weave is in the classical denim fabric is inherently
unstable weave and has a tendency to twist anticlockwise
considering blue side as face side to stable configuration when it is
put in water. Due to this unstable condition the weft yarns lies with
warp yarn at an angle different from 90°. This is regarded as skewing
and if it is not corrected then there will be deformation and leg
twisting in the jeans made out of it. Therefore skewing is corrected
in this section where the fabric is basically passed either over a roller
or through two sets of rollers. The basic idea of correction the skewing
is that warp yarns deliberately pulled at one end so that the weft yarn
can lie with warp at 90° .In the former case the fabric is pulled by a
pair of squeeze rollers and the correction roller is either pushed up
or down. In the later case two sets of rollers are set at the two
extreme ends, the rollers are capable of pulling fabric at different
speeds. What ever is the method of correcting the skew ness, in all
cases attempt is made to compact the fabric sufficiently so that the
tendency of skewing is eliminated.

46. Machine that are used in Tube line are given below:
J - Box
Brushing Unit
Singing / Burning
Washing / Softing
Skew Roller
Dry Cylinder
Shrinkage by rubber belt with 33º pressure
 Calendering / Palmer
Folding
Softening Agent
Softener (Persaftier ISD)
Wetting Agent ( Lionil )
Acetic acid

47. World Wide denim production

48. THANKS TO ALL