manufacturing process of Denim

1. Introduction:
 Denim is a rugged cotton twill textile, in which the weft passes under two or more warp
threads. Denim is the most popular pieces of clothing in the world. In 1969 a writer for
American Fabrics magazine declared, "Denim is one of the world's oldest fabrics, yet it
remains eternally young. “
 Denim was invented in California by Levi Strauss in the 1850s. Denim is designed most
of the famous USA brand and 400 pieces thousand per month. Now a day’s 415 million
pieces of jeans/ Denim sold every year in USA alone and worldwide in denim market is
worth amount of 40 billion dollars.
 Denims are hard wearing, high density fabric with a higher mass per unit area. At least
225 pair of denim jeans can be made from one bale of cotton. Denim is made from 48%
of the world's cotton. Denim fabric was unique in its connection with one color - blue.

2. Types of Denim:
Stretch denim Slub denim Printed Denim
Bull Denim Ring Denim Poly-Denim
 Stretch denim: Elastomeric yarn is used in weft.
 Poly-Denim: Polyester yarn is used in weft.
 Ring Denim: 7,9,12 count of yarn is used.
 Bull Denim : A heavy weight denim weave (14oz. Plus)
 Printed Denim: That has been printed with a pattern-a batik, stripe or floral.
 Slub denim: Slub yarn is used in warp or weft or in both (Cross Hatch Denim).

3. Manufacturing Process:

4. Yarn Manufacturing:
The initial processes of denim manufacturing consist of the regular activities of opening and
mixing or blending of cotton fibers. Carding is done to remove any foreign materials and the
short fibers. Drawing process produces a single, uniform sliver from a number of carded slivers.
Yarn is then spun through Open-End Spinning or Ring Spinning.
Open End Spinning
The Open End Spinning Machines have robots on each side which automatically pieces up
(repairs broken ends). On a different track, they have another robot that automatically doffs
(removes full packages) and starts up a new package. The size and quality of each yarn end are
monitored by the Barco Profile System to ensure uniformity.
Ring Spinning
In Ring Spinning, the spinning frames receive Roving via a transit system from the roving
machine. Yarn is formed from cotton fibers that are twisted together after being drafted by
passing between three steel rolls and three rubber rolls. The yarn then is wrapped on a bobbin
as it spins on a spindle by use of a traveler. The relationship between roll speeds, traveler
speeds and spindle speeds controls the amount of twist in the yarn. Ends down levels and
production information are gathered by the User Ring Expert System. The spinning frames
automatically doff bobbins full of yarn and send them to package winding.
ACG also has the capacity to produce Amsler Open-End yarn, also known as Faux Ring Spun
yarn. This technology enables ACG to impart various slub patterns into an Open-End yarn.
Denim made from this type of yarn has yarn character and surface interest that cannot be
achieved with traditional Open-End yarn.

5. Yarn dyeing
Warp Preparation - Dyeing and Sizing Processes:
Denim fabric mainly Yarn dyed fabric where only warp yarns are dyed with vat dye where
Indigo is used as dye. With the process of oxidization using airflow indigo set in yarn to give its
blue cast. Also sulfur dyes and disperse dyes are used.
Denim is usually dyed with chemically synthesized indigo before being woven. Large balls of
yarn, called ball warps, are dipped in the indigo mixture several times so that the dye covers the
yarn in layers. (These many layers of indigo dye explain why blue jeans fade slightly with each
washing.) It is known that a small amount of sulfur is often used to stabilize the top or bottom
layers of indigo dye.
The dyed yarn is then slashed; that is, it is coated with sizing (starchy substances) to make the
threads stronger and stiffer. Once this operation is complete, the yarn threads are ready to
weave with undies weft yarn threads.
Warp yarns are indigo dyed and sized with the help of some methods:
Indigo Rope dyeing: There are some stages in indigo rope dyeing. They are: 1.Ball warping.
2. Dyeing. 3. Drying. 4. Rebeaming. 5. Beaming. 6. Sizing
Indigo sheet dyeing: Threads from several back beams are combined to form a warp sheet
And dyed then sized on the same machine.
Indigo loop dyeing: The yarn is dyed in a single bath instead of several. The desired depth of
color is attained by passing the yarn through the vat several times then sized on the same
machine
Warp yarn dyeing of Denim

6. Weaving:
Traditional denim fabrics are woven by interlacement of indigo dyed warp and grey weft. The
sequence or order of interlacement of warp and weft may be varied in order to produce
different weave designs. Although the traditional fabric is a 3/1 RHT warp faced fabrics, a
variety of fabrics are made with different weave designs, such as 2/1 twill weave, broken twill,
zig-zag twill, reverse twill etc. Today, denim fabrics are also manufactured with fancy design in
order to meet the latest fashion. These fabrics normally made of weight range of 3.5 to 16.5
oz./yd2 though 21 oz./yd2 has recently developed by Japan.
The classical denim fabrics are made with open end rotor yarn in both warp and weft direction.
However, ring yarn, ply yarn, filament yarn, lycra core yarn, slub yarn are extensively used to
achieve some special effect, lustier, smoothness, and comfort in denim products.
The properties of this finished fabric largely depend upon the fabric construction. The warp and
weft count influence several fabric properties such as weight, fabric tightness, cover, drape,
hand, tensile strength, tear strength, and other fabric properties. All these parameters
influence the durability and comfort of garments.
Traditionally, these fabrics are manufactured for a long time in rapier and projectile looms. But
with the development of air-jet weaving technology, most of the fabrics are manufactured in air
jet looms. The modern air jet looms are equipped with lot of computer controlled attachments
which ensures faultless denim at high production rate. The robust and reinforced frame
structure and perfect balancing of modern air jet looms allows high production speed and
optimum denim quality with less vibration.
Fabric Characteristics:
RHT Twill LHT Twill Warp & Weft Facing

7. Finishing:
 The final woven fabric, wound on a cloth roll.
 The woven Denim Fabrics then goes through various finishing processes, such as
singeing, washing, brushing, drying.
Denim Fabric Treatments:
There are many fabric treatments, and each treatment gives the denim a unique and
fashionable look:
Stone-washed: In traditional washing process, volcanic rocks or pumice stones are added to the
garments during washing
Laser technology: It is a computer controlled process for denim fading
Spray techniques: This technique is based on spraying the chemicals or pigments to get
different effect
Sandblasted: Denim is sprayed with sand or chemicals during the wash process to create a
worn-out appearance.
Denim bleaching: In this process, a strong oxidative bleaching agent such as sodium
hypochlorite or KMnO4 is added during the washing
Vintage/Dirty: Dirty denim is usually created with brown filler yarns.
Diversification of Denim:
 By using Slub/fancy Yarn.
 By changing EPI & PPI.
 By using different count.
 Spandex (Lycra) can be used.
 By applying different wash effect. (Stone, Enzyme, Bleach)
 By applying different mechanical effect. (Rubbing, brushing)
End use:
 Men’s shirt
 Bottom wear
 Critical cargo
 HI-FASHION DENIM Jeans
 Wrinkle Free fabric
 Laser finish
 Dress Pants
 Capri pants
 denim skirts
 Hats
 Jackets
 Overalls
 Shirts
 Booties & shoes
 Shorts
 Sofa covers

8.  Bean bag chairs
 Director-style chairs
 Lampshades
 College Bags
 Travel Bags
 Car Seat Covers
 Denim Curtains
 Denim Body Suit
 Denim Face Mask etc.
CONCLUSION:
Denim is a kind of clothing which is noted for their strength and comfort. They have been worn
by sailors and gold miners as sturdy work pants, by the young as a statement of their
generation, and by the fashionable, who are conscious of the prestige conveyed by designer
names.
Denim's popularity was also on the rise. It was stronger and more expensive. Denim was made
of one colored thread and one white thread. The countries over 20 denim plants, installed
during the last five to six years, have the capacity to produce 20 million gauge fabrics per
month.
Reference:
 http://textilelearner.blogspot.com/2012/07/process-flow-chart-of-denim.html
 http://www.teonline.com/knowledge-centre/manufacturing-process-denim.html
 http://www.cottoninc.com/product/Tech-Assistance-
Training/TextileBasicsEducationalCDs/Denim-Manufacturing/
 http://www.garmentsmerchandising.com/flow-chart-of-denim-manufacturing-process/
 http://www.slideshare.net/Rishad123/2014-2407-denim-apparel-
manufacturing?qid=23d93c6a-8124-4af3-865e-
95313b21b55b&v=qf1&b=&from_search=2
 http://textileflowchart.blogspot.com/2015/01/flow-chart-of-denim-manufacturing.html
 http://www.slideshare.net/sheshir/denim-presentation-35004883?qid=9e4e78c2-8a81-
437b-9c61-e5e0bd93b3b9&v=qf1&b=&from_search=17
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