Recent development in denim
RAJIB CHANDRA GOSH
Traditionally the denim fabric is made of 100 per cent cotton indigo dyed
warp and white weft yarn of coarser counts. Comfort and fit are very
important aspects of denim garments.
So, a lot of research has being done to make stretch denims. elastane fibers are
incorporated into the fabric.
Lycra and Spandex are used in weft yarn.
Ring and open-end core spun yarns are also used in denim to provide stretch property.
To impart fancy effect, different kinds of fancy yarns are being used. The examples of such
yarn are slub yarn and multi-count yarn Other synthetic fibers such as polyester and
polypropylene fibers are also used.
For making softer denim fabrics especially for women wear, blend of Modal, Promodal,
Tancel, and Rayon are being used. Bamboo fibers, hemp fibers and their blends are being
used to make denim fabrics.Now the scenario is different.
Denim fabrics has gained immense popularity and accepted by all irrespective of gender, age-
groups and profession. So, there is tremendous challenge on the part of denim product
manufactures to innovate and develop products to suit requirements of different consumers.
It is attempted to put latest developments in the field of denim fabrics.
Yarn spinning starts with the transfer of the cotton bales from warehouse chosen by
a special software to the blowing room feeder as a initial step of yarn spinning
process. From this point onwards, cotton undergoes preparation processes like
cleaning, opening and blending with the content of other bales. During this process,
the fibers which are too short are extracted.
The cotton fibers are then subjected to a carding operation that ensures that the
fibers are parallel to each other.
The function of carding machine-
Opening of the fiber bundles to separate
Removal of extraneous and dust
Elimination of short fibers
Removal of neps
Obtaining fiber evenness
Producing sliver from cotton fibers
In draw-frames, slivers from different carding machines are brought together to form
a homogenous blend and parallelism of the fibers is further enhanced. The fiber hook-
ends that are a part of the fiber nature are flattened and fibers are further elongated.
In order to monitor the weight per unit length of the Sliver under control highly
developed electronic regulation systems are utlilized. The Sliver from the drawing
frame operation with uniform mass per unit length are further drawn out by the
roving frame operation.
Spinning – Ring Frames
After this operation ,the Rovings are subjected to a further drawing out operation
on the ring machines and are further thinned out to the required yarn thickness. The
yarn produced through Ring Frame is more soft and has more strength and character
as compared to those produced by the Open End machines.
The last phase of the yarn production is the Winding
Process. Here the cops produced by the ring machines are
joined together and transformed into the bobbin format
of specific length . The joining process is very important
from the point of view of productivity of the subsequent
phases where bobbins will be used and final appearance
of the fabric. During the winding process , the yarns are
monitored for every mm of the way by high technology
sensors on the bobbin machines and the faulty areas that
may affect the texture of the fabric are eliminated. Any
yarn defects (unevenness, yarn count, thin & thick places
etc.) are detected and removed during winding. Yarn
spinning is completed by winding process.
Two methods of warping are practiced. These are ball
warping and direct warping. Ball Warping –from the point
of view of color quality and authentic appearance is the
preliminary preparation for the Rope Dyeing System-
which is the preferred system of denim production. The
yarns that will be used in the warping of the fabric are
stacked in the ball warping machines Creel section and all
brought to the front of the machine to be
transformed into Rope . The Rope thus produced and
Cones are warped as ropes at ball warping and prepared
for Indigo rope dyeing process.
In the clothing sector, denim is an indigo blue “evergreen”. Denim fabric is
normally is produced by processing undyed weft yarns with ring-dyed warp
yarns. Ring dyeing is a characteristic feature of denim production. In the
conventional process, the yarns are either processed as a hank (rope) or
spread out next to each other (slasher) and only the sheath is dyed. The dye is
applied in several treatment stages.
Comparison between slasher dyeing and rope dyeing process:
Slasher dyeing Rope dyeing
Continuous process Discontinuous process
Color depth 4.5% Color depth 5.5%
Immersion length 5m Immersion length 9m
Stage production process from the back
beam to the weaving beam
Stages up to production of the weaving beam (
dyeing , long chain beamer, sizing)
Production capacity 9-11 million metres Production capacity 22 million metres
New technology of dyeing (KARL
MAYER’s IOM-Double technology)
• A characteristic feature of denim production is that it is still carried out using traditional
methods, but this can now be done using highly innovative technical systems. The result of
this modernisation is that production can be carried out more efficiently, using fewer
resources and more accurately, i.e. with better reproducibility.
• KARL MAYER is the leader in producing the processing machine.KARL MAYER’s IOM-Double
technology is based on the processing sequences of SLASHER-DYEING but has the
productivity advantages of ROPE-DYEING. This innovative machine concept has been used
successfully in Turkey in particular for some years. Textile companies benefit from KARL
MAYER’s IOM-Double technology.
Advantages of KARL MAYER’s IOM-
maximum production capacities of up to 22 million dyed metres, i.e. the
equivalent of 24 rope dyeing machines
the energy required for steaming and drying is reduced considerably.
improved heat transfer and reduced energy losses.
The interaction between optimum yarn loading, excellent flow-through
patterns and a high dye affinity, together with the specific working width
in the dyeing section, also results in an excellent product quality.
The process guarantees homogeneous dyeing properties as a function of
uniform dyeing across the working width (on the right, in the centre and
on the left).
The yarns are also transported and wound without becoming entangled.
immersion lengths of 1.5 m to 11.5 m
dye depths of up to 5.5%
Nowadays, different functions and processing steps are integrated into
the weaving preparatory processes to increase quality, flexibility and
economic viability. Denim fabrics are mostly woven on high speed air-
jet looms. Various loom manufacturers are offering a number of
modifications to weave fault free high quality fabric.
Main parts of weaving machine:
Development of Weaving machine
here sheds the light on how the weaving machine manufacturers and woven fabric
producers might strengthen the weaving industry by further advanced the rapier
technology with the help of electro-mechanics, electronics, microprocessors,
information technology and their application to the production of woven fabrics.
Development in Filling Insertion
• Versatility in Colour Insertion by Electronic Insertion
• Picking Speed
• Secure Filling Transfer
• Versatility of Rapier Gripper
• Prewinder Switch-off Monitoring
• Light and Small Rapier Head
• Electronic Filling Tension Controller
• Filling Detection at the End of Insertion and Rapier Cleaning Device
Developments in Shedding Mechanism
• Versatility- upto 10 healds; positive cams, maximum 8 harness frames, 12 mm pitch
• Controllable Shed Geometry
• Electronic Setting of Shed Crossing
• Variable Shed Geometry
• Shortest Drive Path
Development of Weaving machine
Development in Let-off Mechanism
The electronic motor driven let-off supplies the loom with necessary
wrap yarn, maintaining the yarn tension constant from full beam to
empty beam. Let-off speed is automatically calculated in context with
loom speed, weft density, wrap beam diameter & close loop tension
Developments in Take-Up Mechanism
The take-up motion is also electronically controlled and synchronized with
let-off motion. Inside the machine the cloth is wound on to a 600 mm
diameter cloth beam. External cloth beam on to batching motion upto 1800
mm cloth roll diameter is also available. The required pick density can be
programmed on the microprocessor keyboard or the jacquard control unit.
The accuracy of the setting ensures easy to adjust of the pick density of the
fabric for optimum fabric weight and minimum yarn consumption.
Finishing section is consists of :
Functional finishes : Functional finishes such as
antibacterial finishes, UV- protection finishes are applied on
denim fabrics to improve functional performances of denim
fabrics. The use of nano-clay is also reported to impart old
look, soft handle, flame retardant and antibacterial properties
to denim fabrics.
Discontinuous finishing method for weft-
The semi-continuous finishing method for
weft- elastic denim
The fully continuous finishing method for
weft- elastic denim
The latest fully continuous finishing method
for weft- elastic denim
Development of finishing section- (Monforts -
possibilities for finishing denim)
Monforts offers a wide variety of processes and ranges for the
finishing of denim. For the finishing of grey denim fabric after
cleaning and singeing, for example (e.g), padders, foam
applicators, minimum-liquor applicators, numerous versions of
stretching- and skewing-units, dryers and compressive shrinkage
ranges. Processes and ranges are offered for desizing,
mercerising, bleaching, stripping, continuous dyeing, washing,
drying and coating in order to create special effects.
Comparison between conventional
and Monforts finishing method
significantly lower stretching forces, less fabric tension, better ‘look and
feel’ with higher production speed and simpler residual moisture control.
The fabric width, skew and number of filling threads is monitored by a
special camera and the measured values are converted into corresponding
control pulses for the range control.
The following stenter with upline Matex ECO-Applicator and a coating
range is then used either for finishing, drying of the coating or surface
stabilisation (fixing), depending on the article.
The machine settings depend on the process to be employed. The fabric
arrives at the range for the compressive shrinking process with a
controlled residual moisture content or with moisture application using
the Matex ECO-Applicator.
Two rubber calenders and two felt calenders ensure a high production
speed with gentle use of the rubber blanket and effective energy
Two rubber calenders and two felt calenders are required to produce, for
example, denim of 14.5oz/yd² with 1-2% residual shrinkage with at least
Low-tension guidance of the fabric during rolling is important for the end
of the process.
Washing of denim garments is one of the most important
processes. This process adds a lot of value to the final
garment. In the washing process, fading effect is imparted
to the denim products. There are many methods to impart
faded effects. The traditionally washing is done using any of
the methods or combinations such as stone washing,
washing with strong bleaching agents such as sodium
hypochlorite, potassium per magnet.
There are two types of denim washing :
• Wet process
• Dry process
Enzyme bleaching wash
Rubber ball wash
Heavy enzyme and stone wash
Development in washing of denim fabrics
These processes are not environment friendly. Alternative
methods have been developed.
Cellulases enzymes are used in place of pumice stone to impart
abraded effect. Laccase based bleaching technique is developed.
This enzyme only attacks indigo dyed yarn bit does affect nature of
white weft yarn. It can also be used to bleach fabrics containing
elastane filaments without losing stretch property.
Laser based techniques are used to give faded effect. Further this
technique can also be used to create motifs on the denim fabrics.
Ozone base denim washing treatments have been developed. In
this process, ozone gas is used as bleaching agent, which attacks
indigo dyes and destroy to create faded look.
World Denim Market
The world denim market is likely to grow continuously
for the next few years. However, supply is growing at
a faster pace.
• World Jeans Market- 51.6$ Billion in 2007 and 56.2$
billion in 2014
• Expected to become 61.4$ billion by 2021
• Global demand growing at 7%, supply at 10%
• Global Denim fabric production in 2015- 4.1 billion mtrs.
• Over 50 percent of denim production is based in Asia
with China, India, Turkey, Pakistan and Bangladesh.
• Between EU, US and China, 75% of world jeans
Estimated Share of Jeans Purchase By Region
North America : 39%
Western Europe : 20%
Japan & Korea : 10%
Rest of the world : 31%
No. Of Denim Mills Worldwide
Region No. Of Denim Mills
Asia(Other countries) 104
North America 9
Latin America 46
Total Denim Mills (World) 515
In conclusion, it is well accepted that denim is
an evergreen fashion and liked by all irrespective
of gender, age and profession. A lot of
innovation and research are to be done on
continuous basis to fulfill requirements of
diverse consumers keeping in mind its impact on
society and environment.