Jan 23, 20218 min read

What is Manufacturing Process of Denim Garments ?

Updated: Feb 9, 2021

Denim may be a durable cotton twill textile during which the weft passes under two or more warp threads. It is

typically wont to make jeans, overalls, and other clothing. Denim was traditionally colored blue with indigo dye to form blue “jeans”.

Manufacturing of Denim

The term “Denim” has originated from the town of Nimes in France where “serge de Nimes” was manufactured. Denim is formed from a vat color , the Indigo dye, which is applied to cotton fabric in loosely held form in layers. As far as manufacturing process of denim cares , it's almost like that of Grey fabric up to the method of weaving with the sole difference that just in case of Denim Fabric, it's dyed at the stage of sizing where as just in case of Grey Fabric, the choice regarding dyeing stage depends upon the finished product. the small print of every process are given below:

Spinning

The initial stage of denim production is Opening and Blending. Opening begins with baled cotton fiber being separated into small tufts. a mix of cotton fibers is formed on each line . These bales are selected using USDA High Volume Instrument (HVI) data, and PCCA’s unique computer blending software produces optimal yarn strength.

Cotton is delivered by air suction from the Opening and Blending lines, through additional cleaning and blending machines, to the Cards. the main functions of Carding are to get rid of foreign matter and short fibers, form the cotton into an internet and convert the online into a rope-like form referred to as a sliver.

The drawing process produces one , uniform sliver from six card slivers. the extra blending, paralleling of fibers and cleaning during this process produces a sliver for Open End and Ring Spinning. For Ring Spinning, however, the sliver must undergo a further process called Roving.

Cotton Fibers are formed into a yarn by centrifugal action in Open- End Spinning. Individual fibers are laid down within the groove of a quick spinning rotor and twisted into yarn. After the cotton fibers are spun into yarn, the yarn is wound into an outsized package.

Open End Spinning

The Open End Spinning Machines have robots on all sides which automatically pieces up (repairs broken ends). On a special track, they need another robot that automatically doffs (removes full packages) and starts up a replacement package. the dimensions and quality of every yarn end are monitored by the Barco Profile System to make sure uniformity.

Ring Spinning

In Ring Spinning, the spinning frames receive Roving via a transit system from the roving machine. Yarn is made 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 because it spins on a spindle by use of a traveler. the connection between roll speeds, traveler speeds and spindle speeds controls the quantity of twist within the yarn. Ends down levels and production information are gathered by the Uster Ring Expert System. The spinning frames automatically doff bobbins filled with yarn and send them to package winding.

ACG also has the capacity to supply Amsler Open-End yarn, also referred to as Faux Ring small stuff . This technology enables ACG to impart various slub patterns into an Open-End yarn. Denim made up of this sort of yarn has yarn character and surface interest that can't be achieved with traditional Open-End yarn.

Fabric Weaving

a. Grey Yarn on Cones

Normally yarns received for weaving in cone forms are either from ring spinning or from open end spinning in single or double fold as needed . For weaving, yarn used is categorised into:

 Warp yarn

 Weft yarn

Normally for Weaving, yarn used as warp should be sufficiently strong to face up to stress and strains exerted during weaving operations. Hence they're having Count Strength Product(CSP) and further sized to extend its strength. The weft yarn is directly used on weaving machines and in some cases, if required, is rewound also so on enhance its performance in weaving.

b. Warping on Sectional/ Direct Warping

The warp yarn is required to be fed into a sheet form to the weaving machines. At warping, the individual cones are put into the creel (the number of cones depends upon fabric construction) and yarn from individual cones is pulled together in sheet form, wound on a barrel called warping beams (for Direct warping) or on weaving beams (for Sectional Warping). Normally if warp sheet is with patterns of various coloured yarns it's processed on sectional warping machine.

c. Sizing of yarn in Set/ Beam to Beam Position

The object of Sizing is to enhance the strength of yarn by chemically binding the fibres with one another and also improve upon its friction resistance capacity by chemically coating the surface of yarn/fibres. Further, number of threads in warpers beam sheet is extremely less against number of threads required in whole width of cloth . Hence multiplication of sheets by drawing yarns together from many warp beams and again making one sheet is additionally performed on sizing machine. On sizing, normally, 8-12 differ size-wise material on warp thread is applied. This improvement in strength and frictional resistance characteristic of warp yarn is important because during weaving, yarn has got to undergo severe strain & stress also as frictional operations.

d. Drawing–in

Weaving is essentially interlacement of two sets i.e. warp and weft threads in desired sequence and pattern. to get this interlacement, warp yarn sheet is bifurcated & opened within the sort of two layers/ sheet and weft thread is inserted between so opened two warp sheets. This operation is named shedding. to perform shedding the warp yarn must be skilled heald eyes of the heald shafts, this operation is named as drawing-in.

e. Beam Gaiting or Knotting on Loom

The drawn weavers beams are fixed on weaving machines, threads are tied and heald shafts are coupled. This operation is named Beam Gaiting. If undrawn warp threads are directly knotted to the threads of finished beams, it's called Knotting. These operations are essential because normally weavers beam can carry only certain length of warp sheet thereon and when so woven, whole length is converted to the material by weaving machine. Further warp length is required to be fed which may be done by knotting or gaiting other beams on weaving machine.

f. Weaving

As stated earlier, weaving is interlacing two sets of yarn and making fabric. One set is named warp thread which is in sheet form, the opposite one is named weft thread which is inserted between two layers of warp sheet by means of an appropriate carrier i.e. Shuttle, Projectile, Rapier, wind , Water current, etc. Depending upon the sort of the weaving machines. the various sorts of technologies available for weaving machines are briefly explained as below:

 Conventional Shuttle Weaving System by Ordinary Looms or Automatic Looms.

 Shuttle less Weaving System by Airjet /Waterjet/Rapier/Projectile

Shuttle loom may be a conventional Technology with much less production on account of slow speed and excessive wear and tear of machinery. This shuttle loom technology has now become obsolete. Denim is woven through Shuttle less Weaving System by using 96 ZAX-e Type Tsodakoma Corporation’s Airjet looms or rapier looms or projectile looms. These looms are distinguished by weft insertion method, which is briefly discussed hereunder.

Airjet Looms

These sorts of looms adopt the newest development in Weaving Technology where weft insertion is completed with the assistance of compressed gas . a really high weft insertion rate up to 1800 metre per minute is achieved. Compared to rapier and projectile looms, these looms are less versatile but are economical and are utilized in mass textile production unit like denim.

Finishing

a. Grey Fabric

The finally woven fabric or Grey Fabric, because it is popularly called, wound on a cloth roll is taken out from weaving machines at certain intervals and checked on inspection machines for possibilities of any weaving fault. If such faults are seen anywhere in fabric during inspection, certain corrective steps are taken at weaving, warping, sizing, etc in order that they will be minimised in subsequent product. this is often a top quality control exercise.

b. Denim Fabric

Denim Fabrics woven of 100% cotton would be very strong and sturdy . Traditionally Blue Denim is warp faced cotton fabric with 3 x 1 twill construction with warp being dyed during a solid colour and weft left un-dyed. the design and quality of the Denim Fabric shall improve after dyeing, the method of which differs from plant to plant. Normally the method of dyeing dictates the technology of Denim manufacturing.

The dyeing for Denim Fabric happens at the sizing stage. Generally there are two hottest methods of dyeing Denim Fabric. They are:

 Rope Dyeing  Sheet Dyeing A company can adopt any of the methods. In countries like India Sheet Dyeing Method is commonly used for manufacture of its Denim Fabrics, which has following advantages over Rope Dyeing Method:

 The technology is less capital intensive.  The technology is a proven one.  The cost of production is lower.  The process time is lower.  The Sheet Dyeing machines are very easy to operate. The only defect in Sheet dyeing is that their is a problem of center to selvedge shade variation.

c. Sheet Dyeing Process

This process eliminates a couple of intermediate processes of the rope dyeing. The yarn sheet is washed chemically like caustic and sodium carbonate and after squeezing the surplus water; the yarn sheet is allowed to undergo Dyeing Troughs just one occasion for oxidation and development of dye on yarn. After dyeing, the dyed yarn is washed again with water for two-three times and finalIy squeezed before allowing it to undergo six drying cylinders. The dyed yarn enters the starching device and sizing is completed . After sizing, the sized warp beam goes for weaving. After weaving, the woven Denim Fabrics goes for various finishing processes consisting of brushing, singeing, washing, impregnation for dressing and drying. Brushing and singeing should eliminate impurities and help to even the surface of the material . Dressing regulates the hand and rigidity of the material while compressive shrinking regulates its dimensional stability.

Even today Denim Fabric without Indigo Dyeing isn't called authentic Denim. Initially when Denim Fabric entered the style market, Denim manufacturers were using Natural Indigo Dye, which was costly and giving a natural finish. Though Synthetic Indigo Dye has gradually replaced Natural Indigo Dye, some unorganized manufacturers still prefer the latter and attract premium after branding them “Natural Dye Used”.

d. Making-Up

Weaving of materials on such multi sizes isn't economical, hence a typical width fabrics is then sent to creating up. Fabrics are dig the specified width as per size required on this machine. Denim Fabric and gray Fabric are thoroughly checked for various sorts of defects such as:

 Weaving Defects

 Uneven Dyeing

 Bleaching and Dyeing Defect

 Oil Stain

 Patches