textile internship report at alok industries ltd
TRANSCRIPT
REPORT OF TEXTILE INTERNSHIP
AT
ALOK INDUSTRIES LTD.
Submitted By:
Ashutosh VatsaKr. Pramendra Sinha
Pankaj PathakSushant Kumar
Batch 2009-13, semester VI
National Institute of Fashion TechnologyPlot no. 15, Sector-4, Kharghar, Navi Mumbai,
Maharashtra, 410210
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ACKNOWLEDGEMENTWe wish to express our gratitude to everybody who has assisted in learning process during this
internship. There are many to whom expression of gratitude is inevitable, but there some special people
who has to be given prominence, without whom we would not have reached the conclusion of this
project so quickly and efficiently.
We wish to thank our Professor, Dr. A.K. Khare for providing this wonderful opportunity, challenging and
motivation. We are also thankful to our Course Coordinator Mr. T.S. Prakash and our textile faculty Ms.
Aboli Naik for their support and guidance.
No amount of Gratitude is adequate for Mr. Dilip B. Jiwrajka, Managing Director, Alok Industries Ltd., for
his consent in allowing us to conduct our internship in their venerated institution.
We express our deep indebtedness to Mr. Manoj Mondol, HR manager and Mr. Akshesh Karnik, HR
executive who guided and supported us through every stage of our internship.
We also wish to thank a couple of senior managers as listed below for their technical guidance and assistance during internship.
Mr. S S Aich, CEO, Vapi PlantMr. Rinku Nath, VP, HR, Training & DevelopmentMr. Arvind Sharma, VP, P.P.C DepartmentMr. B.M Chauhan, Head, Raw Material Storage-GreigeMr. Dayanand Rana, Head, Raw Material Storage-Died FabricMr. Sanjay Baskar, Head, Sizing DepartmentMr. A.G Kurien, Head, Quality Assurance DepartmentMr. Deepak Geedh, Weaving Plant I HeadMr. P.K Das, Weaving Plant IV HeadMr. Pradeep Sharma, Weaving Plant V HeadMr. Ashok Jalela, Weaving Plant VI HeadMr. Anoop Singh, Weaving Plant IX HeadMr. P. Chattopadhyay, Weaving Plant VII HeadMr.Vinay Tendulkar, Weaving Plant III HeadMr. Tek Singh, Inspection & Folding DepartmentMr.Pradeep Bhatt, Packing & Dispatch Department
We take this opportunity to express our affection towards our parents for their consistent faith and
support.
Ashutosh VatsaKr. Pramendra SinhaPankaj PathakSushant Kumar
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Contents1.0 Introduction2.0 Objective of Internship3.0 Schedule of Internship4.0 Spinning
4.1 Blow Room4.2 Carding4.3 Combing4.4 Drawing4.5 Roving4.6 Ring spinning4.7 Open end spinning4.8 Winding4.9 Conditioning4.10 Packing
5.0 Polymerization5.1 Continuous Polymerization5.2.1 Partially Oriented Yarn5.2.2 Texturization5.3 Fully Drawn Yarn
6.0 Weaving6.1 Warping6.2 Sizing6.3 Denting and Drawing In6.4 Weaving
7.0 Preparatory process for Dyeing and Printing7.1 Singeing7.2 Desizing7.3 Pre- Treatment Range7.4 Mercerizing
8.0 Fabric and yarn dyeing8.1 Cold Pad Batch8.2 Continuous Dyeing Range8.3 Benninger Pad Steamers8.4 Dyed Fabric Washing8.5 Yarn Dyeing
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9.0 Printing10.0 Finishing
10.1 Stenter10.2 Sanforising10.3 Calendering10.4 Microsanding10.5 Brushing
11.0 Testing and Inspection11.1 Yarn Testing11.2 Fabric Testing11.3 Defects in Fabric
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1.0 Introduction
B F Tech (Apparel Production) is a 4 years course focusing on application of technology in apparel production. Textile being raw material for apparels is given adequate emphasis in the course. Inputs on textile manufacturing are spread to three semesters. To complement and to comprehend the class room teaching, a 2 weeks internship after Vth semester in textile sector is a part of the course. Internees did this internship at Alok Industries Ltd. at their Silvassa and Vapi plants during 22nd December 2011 – 4th January 2012. The company profile is enclosed as Appendix I.
2.0 Objective of Internship
The main objective of this internship was to learn
The process of spun yarn production, different qualities of yarn produced and reasons for variation.
Grey fabric (both woven and knitted) production, defects associated with it and treatments carried out on it depending upon its properties.
Dyeing, Printing and Finishing of fabric, Textile testing and their quality aspects both technical as well as for commercial purposes.
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3.0 Schedule of Internship:
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4.0 Spinning
Raw Materials
Cotton comes in bale form of bales, the weight of this baggy structure is about 265 Kg. The
different varieties of cotton like BT cotton, conventional cotton like Supima from USA, Gizas
from Egypt, Imported cotton from contamination free origin, Organic and Organic Fair trade
cotton are used for yarn manufacturing. The staple length varies from 28mm to 33mm.
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The raw cotton is procured from the open market, primarily from states of Gujarat,
Maharashtra and Andhra Pradesh. Cotton is also imported from Egypt. An average nine months
inventory of raw cotton is maintained primarily for yarn manufacturing. Alok promote contract
farming and buying cotton in bulk.
4.1 Blow Room
Objective
To open the compressed bale of cotton.
To extract impurities and other foreign matters
from cotton by opening and beating.
To allow passage of clean cotton either as fluffy mass or as lap (chute feed or lap feed)
to the next machine
Input
Bale of cotton
Bale weight – Average 265 kg
Relative humidity maintained in blow room (preparatory) – 55-60%
Output
Clean open cotton fiber.
A blow room is the area of a spinning unit where opening, cleaning, mixing and lap making of
cotton fiber take place on machines. The cotton is received in the mill in a hard pre-bale form
which contains several impurities.
The blow room machinery performs function of
opening hard pressed bales of cotton and cleaning
the cotton of impurities. Trash and foreign matter is
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extracted from the cotton with the least amount of lint loss. The amount of waste extracted
would depend on the amount of trash in the mixing.
At Alok Industries Ltd., UNIFLOCK
automatic bale opener machines are
used to open bales. The bales being
opened are placed lengthwise or
crosswise on both sides of the bale
opener, and the take-off unit can
process up to four different assortments. The machine opens the bales in micro tuft for
effective cleaning and dust extraction. This machine gives the output of up to 1400kg/hr.
These micro tufts pass by pipes using pneumatic force. Dust particle are removed manually as
well as using machines.
Vision shield and magic eye, are the machine used in Alok for detecting of dust particles.
Vision shield: this machine uses an ultraviolet light source, combined with a light
detector, to identify foreign bodies.
Magic eye: This machine can detect white colored and difficult to identify by naked eyes
synthetics like Polypropylene, independently of optical bleaches or polarization effects.
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INFRASTRUCTURE
Machines used in blow room:
S. No. Machine/Equipment Purpose No. of Machines/ Equipments
1 A 11 UNIfloc Bale Openers 4
2 Jossi THE VISION SHIELD MPIX
foreign fiber detection
8
3 B 11 UNIclean pre-cleaners 2
4 B 12 UNIclean pre-cleaners 2
5 B 70 UNImix blenders 4
6 B 71 UNImix blenders 4
7 B 60 UNIflex fine cleaners 5
8 A 78 UNIstore feeder 1
Table 1: Machine Capacity in Blowroom
4.2 Carding
Carding is known as the ‘heart of spinning’. This process is done for the individualization of the
cotton fibers. The fibers after this process get arranged into parallel form from zigzag
arrangement.
Objective
1. To open the flocks into individual fibers
2. Cleaning or elimination of impurities
3. Elimination of dust
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4. Elimination of short fibers
5. Fiber blending
6. Fiber orientation or alignment
7. Sliver formation
Input
Cotton in the form of lap
Output
Carded sliver
Waste
Flat stripes
Licker
Cylinder fly
Carded sliver is either directly used in Open-End Spinning or used for further processing for ring
spinning. At Alok Industries Ltd., C-60 cards machines are used for carding. Speed of carding
machine is 50kg/hr.
There are two types of feeding to the cards,
Lap feed system- fibers are formed into a lap or a compact sheet
Chute feed system- flocks are transported pneumatically.
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At ALOK Industries Chute Feed system is used.
The advantages and disadvantages of Chute Feed system are as follows:
Advantages
1. High performance in carding due to high degree of openness of feed web.
2. Labor requirement is less due to no lap transportation and lap change in cards.
3. For high production cards, only chute feeding system is suitable.
Disadvantages
1. Linear density of the web fed to the card is not as good as lap.
2. The installation is not flexible.
3. Auto leveler is a must for controlling weight per unit length, hence investment cost and
maintenance cost is more.
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Principle of Carding:
Short fibers which are responsible for hairiness and reduction in strength are to be removed
Cotton is introduced in the form of flocks and obtained in the form of slivers.
At carding, the faults like neps, hooked ends can come. These faults can be rectified at the
later stages.
Rollers used in the carding machines are fixed at certain distance that defines the minimum
length of fiber required. This eliminates shorter fibers but also gives rise to hooks (fibers
held by front rollers form trailing hooks while fibers held by back rollers form leading
hooks).
INFRASTRUCTURE
Machines used in Carding:
Machine models No Of machines
Rieter C 60 cards 43
4.3 Combing
When the fiber is intended for fine yarns, the sliver is put through an additional straightening
called combing. Combing is the process which is used to upgrade the raw material. It influences
the following yarn properties:
1. Yarn evenness
2. Strength
3. Cleanness
4. Smoothness
5. Visual appearance
In addition to the above, combed cotton needs less twist than a carded yarn because the short
fibers are removed.
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Purpose of Combing:
In order to produce an improvement in yarn quality, the comber must perform the following
operations:
1. Elimination of short fibers
2. Elimination of remaining impurities
3. Elimination of neps
The basic operation of the comber is to improve the mean length or staple length by removing
the short fibers. Since fineness of short fibers (noil) is low, the overall micronaire of the sliver
after combing is high. Because of combing, fiber parallelization increases.
Input
Uni-Lap
Output
Combed sliver
PROCESS
For combing sliver from the carding, it is passed through pre-comber drawing and then through
the uni-lap to get smaller lap of cotton. These laps are then fed to combers to get sliver, which
has 14 % to 18 % of shorter staples removed from it.
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UNIlap E 32 combing preparation machines
In this operation, fine-toothed combs continue straightening the fibers until they are arranged
with such a high degree of parallelism that the short fibers are combed out and completely
separated out from the longer fibers.
INFRASTRUCTURE
Machine models No Of machines
UNIlap E 32 combing preparation machines 8
E 65 combers 34
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4.4 Drawing
Objective
Through doubling, the slivers are made even
Doubling results in homogenization (blending)
Through draft, fibers get parallelized
Hooks created in the card are straightened
Through the suction, intensive dust removal is achieved
Autoleveller maintains absolute sliver fineness
Input
Combed or carded sliver
Output
Drafted sliver
The main output of drawing is a more uniform sliver with uniform mass/length distribution.
PROCESS
In this process six sliver are combined together. The
combining of several fibers for the drawing, or drafting,
process eliminates irregularities that would cause too
much variation if the slivers were pulling through singly.
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The draw frame has several pairs of rollers, each advanced set of which revolves at a
progressively faster speed. Each of four set of rolls runs successively faster than preceding set.
The last set runs approximately six times as the first set; consequently, sliver coming out is the
same size as each one of six going in. but is attenuated to six times the length per minute. The
sliver is neatly coiled again in roving can by coiler head. The sliver is now much more uniform
and fibers much more nearly parallel.
Draw frame contributes less than 5% to production cost of yarn. But its influence on quality is
very big, because drawing is the final process of quality improvement in the spinning mill and
quality of draw frame sliver determines the final yarn quality.
INFRASTRUCTURE
Machine models No Of machines
SB-D 40 breaker draw frames 18
RSB-D 40 auto leveler draw frames 19
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4.5 Roving
Objective
Reduces the thickness of the sliver into roving, imparts twists and winds it around a bobbin.
The main function of speed frame is to make roving from the draft sliver that has strength
to withstand the tension variations at ring frame.
Input
Sliver
Output
Rove
Purpose of Roving:
Sliver is thick, untwisted strand that tends to be hairy and to create fly. The draft needed to
convert this is around 300 to 500. Drafting arrangements of ring frames are not capable of
processing this strand in a single drafting operation to create a yarn that meets all the normal
demands on such yarns. Hence, roving frame is used.
PROCESS
The can of sliver from drawing frames is fed between three sets of drafting rolls. Each following
set of rolls runs faster than preceding sets. This pulls sliver and thins it down, making fibers
nearly parallel. Drawing out and twisting take place until the cotton stock is about the diameter
of a pencil lead.
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The spindle turns flyer and is driven at a constant speed. The front rolls are set at a speed that
gives strand coming out of the rolls a predetermined number of turns of twist per inch as it
move along between rolls and flyer. The bobbin is driven by a source separate from gear that
drives spindle and flyer. The bobbin is regulated to turn automatically at a speed sufficiently
faster than flyer, which causes roving to wind on bobbin at same rate as it is delivered by front
roll. To this point, only enough twist has been given the stock to hold the fibers together.
INFRASTRUCTURE
Machine models No Of machines
F 15 roving frames with 160 spindles each 18
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4.6 Ring Spinning
Ring Frame gives the final output for spinning i.e. yarn. The productivity of the factory is
determined by the output of the ring frame.
Objective
It reduces the thickness of the roving to the desired yarn count by means of drafting rollers.
Drafting arrangement is the most important part of the machine. It influences mainly
evenness and strength.
It imparts twists into the yarn thus strengthening it and preventing short fibers from
protruding.
Packing it in a more easy to handle package.
Input
Rove
Output
Bobbin
PROCESS
The ring frame, which is general in use, is more suitable for the manufacture of cotton yarns in
mass production. Its hundreds of spindles, whirling thousands of revolutions per minute, and its
constant spinning action provide a fast operation.
The ring spinning frame completes the manufacture of yarn:
1. By drawing out the roving2. By inserting twist3. By winding the yarn on bobbins-all in one operation.
The principle of spinning is same as that used in roving except that the operation is more
refined and a ring and traveler are used instead of the flyer. The roving, on bobbins, is placed in
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the spinning frame. From bobbin roving is fed between set of drafting rollers running at
successively higher rates of speed and is finally drawn out to yarn of the size desired to draw
strand down to its final desired size.
The spindle turns bobbin at a constant speed. The front set of rolls is adjusted to deliver yarn at
a speed sufficient to insert desired amount of twist as strand moves along. The traveler glides
freely around ring. The tension caused by drag of traveler causes yarn to wind on bobbin at
same rate of speed as it delivered by rolls.
The bobbins of yarn are removed for such processing as may be desired; for example, the yarn
may be reeled into skeins for bleaching or may be wound on cheeses, or spools, for ultimate
weaving. Where it passes through several sets of rollers
INFRASTRUCTURE
Machine models No Of machines
Reiter G 331 ring spinning machines with 1200 spindles each 21
Reiter K 441 Comfor Spin machines with 1200 spindles each 63
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4.7 Open End Spinning
Features:
Higher Productivity - it increases the productivity and reduces the cost of manufacturing
Large Final Package - The final package size has continued to increase. The final package size is important because it reduces tube change frequency and thus reduces idle time for creeling
Less power consumption - Using individual motors and electronic controls for each of the various drives of the machine maximize energy efficiency and minimizes downtime.
Input
Carded sliver
Output
Open end spun yarn
PROCESS
Sliver is fed into the machine and combed and individualized by the opening roller. The fibers are then deposited into the rotor where air current and centrifugal force deposits them along the groove of the rotor where they are evenly distributed. The fibers are twisted together by the spinning action of the rotor, and the yarn is continuously drawn from the centre of the rotor. The resultant yarn is cleared of any defects and wound onto packages.
Open end spinning machines can run up to 1, 40,000 rpm. The production rates of rotor spinning is 6-8 times higher than that of ring spinning and as the machines are fed directly by sliver and yarn is wound onto packages ready for use in fabric formation the yarn is a lot cheaper to produce.
INFRASTRUCTURE
Number of rotors: 5424
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4.8 Winding
Package obtained from ring frame is bobbin which holds a small amount of yarn. It is not easy as well as convenient to transport the cops from one place to other. Secondly, these packages can’t find any use in weaving where a long and continuous supply of yarn is required. Hence, six bobbins are combined to make a cone. This is done by Autoconer.
Purpose
• To remove yarn faults
• To make bigger package (60 gram bobbins to 2 kg cones) by splicing
• Lubrication of yarn
Input
Bobbin
Output
Cone
PROCESS
During winding, various faults such as neps, thick and thin section are removed.
The machine is controlled by computer. Six bobbins are arranged in a stand that can be rotated. The yarn from a single bobbin is taken by the machine. It is passed through a waxing rod that provides wax. Then, it is passed through electric yarn clearer and splicing unit. This unit contains sensing device(optical and capacitance based) that detects the presence of any fault like thick or thin places, contamination, hairiness, nep formation, weak places. Such places are cut or spliced and the two ends of the yarn are tied into a tiny knot.
A tensioning device maintains the tension in the yarn and thus helps in maintaining uniform tension while winding the yarn.
INFRASTRUCTURE
Machine models No Of machines
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Murata 21C winders 84
4.9 Conditioning
The normal moisture content of cotton is around 6-6.5%. After converting to yarn, cotton has only 4% of moisture. A conditioning machine imparts required amount of moisture and strength to the yarns. It uses steam, high temperature and pressure. Steam penetrates into the material and increases the strength of the yarn. If conditioning of yarn is not done, problems like snarling and end twists can occur.
Purpose
Increase weight and strength of the cone. Increase absorption capacity of dyeing agents.
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4.10 Packing
Mainly there are two types of packing methods:
1. Pallette Packing – Cones or cheeses wrapped in plastic are placed on top of one another
and the entire package is wrapped in plastic. The maximum number of layers possible is 12.
2. Carton Packing – Cones or cheeses are wrapped in plastic and packed into baseboard
boxes. Depending upon the cone or cheese weight, the size or capacity of the carton varies.
There is another type of packing method which is based on customer orders, which is called
carton pallet packing. In this method of packing, cartons already filled with cheeses or cones are
placed on top of each other in layers and then the entire package is wrapped in plastic.
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5.0 Polymerization
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5.1 Continuous Polymerization
Input:
PTA ( Pure Terapthelic Acid )
MEG ( Mono Ethylene Glycol )
TiO2 ( Titanium Dioxide )
DEG (Di ethylene Glycol )
Sb2O3 ( Antimony Trioxide )
Polymerization involves reaction of PTA (Pure Terephthelic Acid) and MEG (Mono Ethylene
Glycol) to form Polyethylene Terephthalate (PETE).
Output:
Polyethylene Terepthalete (PETE)
PROCESS
This process involves two steps reaction.
Esterification: This is the first step on where PTA and MEG were continuously mix in a
specific ratio and fed in to the I st reactor called Esterifies. Reaction takes place vigorously
in presence of heat. The intermediate product formed is called as monomer. The by-product
formed during reaction is water, which condensed and sent to organic stripping column
where organic impurities are stripped and burnt in boiler. The water is sent to Effluent
Treatment Plant (ETP).
Poly-condensation: Monomer is subsequently poly-condensed into other two reactors
called poly-condensation reaction which is second step of the reaction. Before feeding
monomer to polymerization section different additives added such as TiO2, Sb2O3, and
DEG. In polymerization reaction monomer undergoes poly condensation under high
temperature and low pressure to form polymer.
This polymer is continuously fed to POY spinning plant, FDY spinning plant and Chipper.
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5.2.1 Partially Oriented Yarn
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In melt spinning, the fiber-forming substance i.e. polymer chips is melted for extrusion through
the spinneret and then directly solidified by cooling. The polymer is melted at high temperature
& pressure and pumped through a spinneret (die) with numerous holes (one to thousands) as
per denier requirement.
The molten fibers are cooled by the help of quenching, solidified, and collected on a take-up
winder. Stretching of the fibers in both the molten and solid states provides for orientation of
the polymer chains along the fiber axis. This process of stretching the fiber is called drawing.
Drawing is typically accomplished by passing the filament around a series of drum or rolls. Each
drum is increased in speed to stretch the filament.
INFRASTRUCTURE
POY 1 = 150 Metric Tons per Day (MTPD) & 10 lines
POY 2 = 300 MTPD & 12 lines
5.3
Fully Drawn Yarn
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Fully Drawn Yarn (FDY) is produced by a process similar to POY manufacturing except that the
yarn is produced at higher spinning speeds coupled with intermediate drawing integrated in the
process itself. This allows stabilization through orientation and crystallization.
PROCESS
Yarns are produced by a continuous polymerization process.
All critical yarn properties such as tenacity, elongation, Uster variation and boiling water
shrinkage are closely monitored and controlled.
Controlled interlace enables the yarns to be twisted or sized in subsequent operations. FDY is
mainly used as weft or weaves in making fabrics. FDY can be knitted or woven with any other
filament yarn to get fabric of various different varieties.
It is mainly used in Home Furnishing Fabrics, Fashion Fabrics, Denim, Terry Towel and others
INFRASTUCTURE
FDY = 200 MTPD & 12 lines
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5.2.2 Texturisation
The molecular structure of Partially Oriented Yarn (POY) is not oriented and has very high
elongation. It cannot be used directly for twisting, weaving or knitting. To stabilize the POY and
make it usable for the subsequent end-use, texturising is done.
Texturising is a thermo mechanical process to make POY more suitable for manufacturing of
fabric by permanent re-orientation of its molecular structure and providing better and superior
texture to the yarn.
PROCESS
The POY threads are first passed through a yarn feed device where it is stretched to the
required denier.
It then goes through the first heater for initial set-up.
It is then passed through a cooling panel and a friction disc unit where it is twisted and
untwisted about 25-30 times.
It then passes through another set of rollers stabilizing heater and then through a third
set of feed rollers and then finally through oil rollers.
Ultimately the yarn is wound on the paper tube running on the take up roller.
The yarn now becomes suitable for twisting, weaving (only for weft) and knitting.
For making the yarn suitable to use as warp yarn (in weaving), roto yarn is produced. For
producing roto yarn, interlacing jets are fitted next to second set of feed rollers in the yarn
path.
Compressed air with about 2.5 to 3.0 kg pressure is blown while passing through the jets,
where in the filaments are intertwined by a series of prescribed short periodic compact nodes
(nips) without causing any radial disarrangement of the filaments. The yarn becomes suitable
for using as warp yarn for weaving application. It also eliminates downstream operations like
twisting or sizing thereby reducing cost of warp yarn for weaving application.
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The finished product so obtained is then weighed on electronic digital-weighing machines to
ascertain the quantity manufactured.
The quality aspect is also taken care by drawing a random sample of texturised yarn from the
lot manufactured and the same is tested on laboratory equipment for count and quality
assurance. Thereafter, the cones are packed in cartons and sold either to various weavers
domestically or exported for manufacturing of fabric.
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6.0 Weaving
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6.1 Warping
The process of arranging a convenient number of warp yarns that can be collected in a sheet form and wound on to a warper’s beam.
There are two types of warping methods followed:
Direct warping (beam warping)
Sectional warping (pattern warping):
Direct Warping (beam warping): It is used for long runs of grey yarns, single colour yarns and
simple patterns of coloured yarns. It can be used to make warp sheets. The total amount of
coloured yarns involved is less than 15% of the total.
Direct warping machines are not computerized.
No. of direct warping machines = 3 (JUPITER)
Suction devices are provided in between warping machines which suck all the unwanted cotton fibres flying.
Sectional Warping (pattern warping): It is used for short runs especially for fancy pattern fabrics
where the amount of coloured yarn is more than 15% of the total.
Sectional warping is a quick way to warp a loom with a sectional warp beam and is best suited for
very long warps (15 yards or more), any size or style of yarn and 2 inch repeats (most sections on
a sectional warp beam are 2" wide). It is not very well suited for mixed warps with many or
random yarn changes. It also requires more space and equipment than other warping methods -
spool rack with bobbins, bobbin winder, and sley hook and a tension box or warping
paddle/guide.
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PROCESS - Sectional Warping:
Warp is winded onto spools (bobbins) - One spool per each warp end per 2" of warp.
Only one section of sectional warp beam is winded at a time.If the weaving is set at 12 e.p.i,
and the sectional warp beam sections are 2", 24 bobbins of warp are needed in the spool
rack (2" x 12 e.p.i. = 24 warp ends, hence 24 bobbins per 2" section).
The spool rack is positioned behind the loom.
The warp is centred and number of warp sections is counted. For a 28" wide fabric, the
centre 14 sections are used (28" divided by 2" sections = 14 sections).
A cord is tied to the warp beam in each of the sections used.
A warp end is threaded from each bobbin through the tension box or warping paddle. The
tension box or guide should be attached to the back beam to help in winding the warp ends
onto each section with even tension. The bundle of warp ends is knotted as close to the end
as possible.
Beginning at either of the outside sections of the specified sections, the cord is tied from
the warp beam to the knotted warp ends using a clove hitch knot. Starting at one side and
filling sections in order straight across the beam will produce fabric with warps tight on one
end and loose on the other. Similarly, starting at the centre and working towards the edges
will produce fabric with rippled edges.
The beam is turned, watching carefully to see that the section fills evenly. If the warp piles
up unevenly, position of the tension box is adjusted. Each revolution of the beam is counted
as first section is filled. All the other sections should be filled with the same number of turns
to avoid tension problems in the warp.
i. When the section is full, a piece of masking tape is placed across the warp ends to keep them in
order. The tape takes the place of a cross. The warp is then cut one inch beyond the tape. The
tape is pinned into the filled section to secure it.
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ii. The tension box or paddle is moved to the other outside section and filled.
iii. When all the sections are full, pins are removed from each section and warp is pulled over the
back beam toward the shafts.
iv. Thread the loom is threaded as for warping back to front (heddles are threaded; the
reed is slayed and tied onto the front apron rod).
INFRASTRUCTURE
The sectional warping machines are fully computerized.
Creel capacity = 672
Hence, no. of sections = 672/ (no. of ends per section)
No. of sectional warping machines = 9 (PRASHANT GAMATEX, SUCKER MULLER AND JUPITER)
FEATURES:
Separate warping & beaming structure
Hydraulic Disc Brakes
Constant Beaming Tension
Digital / Graphic On Line Display for desired process data
Solid steel drum - Dynamically balanced.
Frequency variable A/C drives
Hydraulic doffing & donning device
Auto section advancing
Constant warping and beaming speed
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Lost end memory & auto stop during beaming
On Site Programming Facility
Individually Controlled Tensioner Type model
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6.2 SizingThe main purpose of sizing is to improve strength and abrasion resistance of the warp yarns by causing the
fibres to adhere together to make smooth and to lubricate the warp yarns so that there is minimum
friction where they rub together various parts in the weaving process.
Sizing Ingredients:
Adhesives: Modified starch (texoplast), fabric glue, thin volume starch, Potato starch, starch from corn,
wheat, rice, etc., Carboxyl methyl cellulose (CMC), Poly-vinyl alcohol (PVA), Polyester resin (acts as binder).
Lubricants: Mineral waxes, oils, vegetable waxes and oils, animal fats
Additives: Salicylic acid, zinc chloride, phenol, emulsifier, softeners, Polyethylene glycol
CHEMICAL 16Te 40COL 40
GREY
50 60 70 20 16OE Sample
sizing
Texoplast 40 50 50 70 60 50 20 70 ___
PVA 6 6 10 10 10 15 ___ 10 8
Falixlose 25 25 25 ___ ___ ___ 60 20 ___
Seycofilm 4 6 6 12 15 15 4 6 3
M. Tallow 5 5 5 5 5 5 5 4 3
Pep 1000 100 100 100 100 100 100 100 100 ___
LV 40 1 ___ ___ ___ ___ ___ ___ ___ ___
Water 15’’ 14.5’’ 14.5’’ 14’’ 14’’ 14’’ 14’’ 17’’ 100
Table 2: Chemical Composition of sizing for different types of yarns.
1’’= 37.75 litres
INFRASTRUCTURE:
SUCKER MULLER –HACOBA with PLC device( programmable logic control): No. of machines = 4 JUPITER ( No. of machines = 3) AMBICA ( No. of machines = 2)
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TECHNICAL DETAILS:
Feeding device : Obtain a good point of grip for the warp. This comprises of the following parts:
Pressure roller
Carrier roller
Floating roller
Control bridge
Rotary switch
Guide roller
Contactless switch
Squeezing rollers
Automatic squeezing roller control ( PLC)
MEASURING AND CONTROL DEVICES FOR DEGREE OF SIZING
If degree of sizing is too high or low, risk of thread breaks is increased.
Degree of sizing(%) = [Sa(%) * K(%)] / (100%) ; where Sa = Sizing liquor take up.
It is the ratio of the liquor taken up to the weight of untreated yarn. K = Concentration.
It is measured by a refractometer.
Factors Affecting Degree of Sizing:
Concentration
Viscosity of sizing liquor
Temperature of sizing liquor
Speed
Squeezing pressure
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6.3 Denting and Drawing – In
All the warp threads have to be threaded through the heald eyelet and its gap in the reed prior to
weaving. The heald is the part of the loom that is used to move the warp threads up and down. The
threads pass through eyelets on the heald. For a simple weave pattern alternate eyelets are moved
up to raise the corresponding warp threads, and the threads between are moved down. When the
shuttle travels back their positions are reversed.
INFRASTRUCTURE:
1) STAUBLI DELTA 200: The DELTA 200 is a high-performance drawing-in installation. It is used
wherever high production performance, a wide field of applications, and maximum flexibility are
required. The DELTA 200 draws-in warp yarns directly from the warp beam with 1 or 2 sheets, and
optionally up to 4 sheets.
2) STAUBLI DELTA 110: These drawing-in installations are designed for weaving mills with medium
drawing-in requirements. The DELTA 110 also handles drop wires and is a universal installation.
Furthermore, a module is available that is specially designed for drawing-in course yarns. Drawing-
in takes place directly from the warp beam with 1 warp sheet, or optionally with 2 warp sheets.
DELTA 110 200
Drawing-in speed (ends/min) 100/140* 200
Number of warps in 8h (ca. ) 2-5 4-8
Warp widths (m) 2.3/ 4.0/ 6.0 2.2/ 2.8/ 4.0
Number of warp sheets 1 (2*) 2 (4*)
Reed density( teeth/ dm) 500 500
Max. number of frames (J/C-healds) 20 28
Max. number of frames (O-healds) 16 20
Max. rows of dropwires ____ 8
Number of dropwire paths ____ 2
Drawing-in element Hook Rapier
Yarn count range (tex) 3-250 3-330
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Sequence of Functions:
Band gripper starts the drawing-in sequence before all modules are ready for drawing-in.
If reed module is not ready, it reports after reed test.
Gripper enters the dent (can be stopped if reed module is not ready, otherwise continues its
forward motion.
Heald module reports at heald test. If it is not ready, band gripper is stopped before
passing through heald eye. If it is in ready state, gripper moves on.
Drop wire module reports at drop wire test. If it is not ready, band gripper is stopped before
penetrating eye of the drop wire. If ready, gripper moves on.
Yarn supply module reports at yarn test. If it is not ready, band gripper is stopped before
entering yarn take over. If ready, the gripper continues its motion.
After yarn take over, band gripper which grips the yarn withdraws.
Band gripper withdraws past the drop wire and heald positions.
Drop wire and heald distribution systems move on.
Reed transport ensures the reed position.
Yarn ejectors are actuated in position ‘e’ and ‘f’ (in the diagram).
One drawn-in cycle is over.
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6.4 Weaving
It is a method of fabric production in which two distinct sets of yarns or threads are interlaced at right angles to form a fabric or cloth. The other methods are knitting, lace making and felting. The longitudinal threads are called the warp and the lateral threads are the weft or filling. The methods in which these threads are inter- woven affects the characteristics of the cloth.
Cloth is usually woven on a loom, a device that holds the warp threads in place while filling threads are woven through them. Weft is an old English word meaning "that which is woven". A fabric band which meets this definition of cloth (warp threads with a weft thread winding between) can also be made using other methods, including tablet weaving, back-strap, or other techniques without looms.
The way the warp and filling threads interlace with each other is called the weave. The majority of woven products are created with one of three basic weaves: plain weave, satin weave, or twill. Woven cloth can be plain (in one colour or a simple pattern), or can be woven in decorative or artistic designs.
PROCESS AND TERMINOLOGY:
In general, weaving involves using a loom to interlace of two sets of threads at right angles to each other: the warp and the weft (older woof). One warp thread is called and an end and one weft thread is a pick, the warp threads are held taut and in parallel order, typically in a loom of which there are many different types. Weaving can be summarised as a repetition of these three actions:
Primary Motions Secondary Motions
Tertiary Motions
Primary Motions:
Shedding: Where the ends are separated by raising or lowering heald frames (heddles) to form a clear space where the pick can pass
Picking: Where the weft or pick is propelled across the loom by an air-jet, a rapier or a shuttle
Beating-up or battening: Where the weft is pushed up against the fell of the cloth by the reed.
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Secondary Motions:
Let off Motion: where the warp is let off the warp beam at a regulated speed to make the filling even and of the required design
Take up Motion: Takes up the woven fabric in a regulated manner so that the density of filling is maintained
Tertiary Motions:
The stop motions: to stop the loom in the event of a Thread break. The two main stop motions are the
Warp stop motion Weft stop motion
Others are:
Temple Leno Stop
Catch Cord Stop
Waste Cutter
The principal parts of a loom are:
The frame The warp-beam or weavers beam
The cloth-roll
The heddles and their mounting,
The reed.
The warp-beam is a wooden or metal cylinder back of the loom on which the warp is wound. The threads of the warp extend in parallel order from the warp-beam to the front of the loom, and are attached to the cloth-roll. Each thread or group of threads of the warp passes through an opening (eye) of a heddle. The warp threads are separated by the heddles into two or more groups, each controlled and automatically drawn up and down by the motion of the heddles. In
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the case of small patterns the movement of the heddles is controlled by “cams” which move up the heddles by means of a frame called a harness; in larger patterns the heddles are controlled by a dobby mechanism, where the healds are raised according to pegs inserted into a revolving drum. Where a complex design is required, the healds are raised by harness cords attached to a Jacquard machine. Every time the harness (the heddles) moves up or down, an opening (shed) is made between the threads of warp, through which the pick is inserted.
The rapier-type weaving machines do not have shuttles, they propel the weft by means of small grippers or rapiers that pick up the filling thread and carry it halfway across the loom where another rapier picks it up and pulls it the rest of the way. Some carry the filling yarns across the loom at rates in excess of 2,000 meters per minute. Manufacturers such as Picanol have reduced the mechanical adjustments to a minimum, and control all the functions through a computer with a graphical user interface. Other types use compressed air to insert the pick, and others small projectiles. They are all fast, versatile and quiet.
The handloom weaver sizes his warp in starch mixture for smoother running. He warps his loom (loomed or dressed) by passing the warp threads through heddles on two or more harnesses. The power weaver’s loom is warped by separate workers. In operation the warp threads are moved up or down by the harnesses creating a space called the shed through which the pick will pass. The harnesses can be controlled by cams, dobbies or a Jacquard head.
The raising and lowering sequence of warp threads in various sequences gives rise to many possible weave structures:
Plain weave : plain, and hopsacks, poplin, taffeta, poult and grosgrain.
Twill weave : these are described by weft float followed by warp float, arranged to give
diagonal pattern. 2/1 twill, 3/3 twill, 1/2 twill. These are softer fabrics than plain weaves
Satin weave : satins and sateens
Complex computer-generated interlacing.
Pile fabrics : such as velvets and velveteen
Both warp and weft can be visible in the final product. By spacing the warp more closely, it can completely cover the weft that binds it, giving a warp faced textile such as repp weave.
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Conversely, if the warp is spread out, the weft can slide down and completely cover the warp, giving a weft faced textile, such as a tapestry or a Kilim rug.
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Weaving- Fabric Manufacturing Process
Winding Warping or beaming Sizing Drawing in, Looming Pirning (Processing the weft) Weaving
Measurements:
Ends and Picks: Picks refer to the weft, ends refer to the warp. The coarseness of the cloth can be expressed as the number of picks and ends per quarter inch square, or per inch square. An end is always written first. For example: Heavy domestics are made from coarse yarns, such as 10's to 14's warp and weft, and about 48 ends and 52 picks.
Weaving Department Of Alok Industries Ltd.:
There are total 14 weaving units in Alok Industries.
Unit Number Product
1Wider Width fabric
2
3 Fine Count for Print, Chambray
4 Yarn Died (Shirting & Suiting Fabric)
5 Wider Width (Defense)
6 Wider Width Fabric &
7 Wider Width Fabric
8 Yarn Died (Shirting & Suiting Fabric)
9A Wider Width Fabric
9BBatching(Defense Purpose)
9C
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9DYarn Died Fabric
9E
Unit Number
Machine Type Number Of Machines
1 Pinacol Air Jet Looms with Cam,340 cms(2 pick insertion)
80
2 Pinacol Air Jet Looms with Cam,340 cms(2 pick insertion)
80
3 Toyota air Jet Looms 52Pinacol Rapier Loom(Jacquard) 12Sulzer Rapier Loom(Jacquard) 16
4 Pinacol Air Jet Looms with Dobby 32Sulzer Rapier Loom with Dobby,220 cms 02Sulzer Rapier Loom with Dobby,190 cms 28Pinacol Rapier Looms with Dobby 40
5 Pinacol Air Jet Looms with Cam 96Pinacol Air Jet Looms with Dobby 48
6 Pinacol Air Jet Looms with Cam 152Pinacol Rapier Looms with Dobby 76Toyota air Jet Looms with Cam 50Toyota air Jet Looms with Cam 26
7 Pinacol Air Jet Looms with Cam 100Pinacol Air Jet Looms with Dobby 52Toyota air Jet Looms with Cam(2 pick insertion) 26Toyota air Jet with Cam(4 pick insertion) 12
8 Vamatex Rapier Loom with Dobby 76Toyota air Jet Looms with Cam 12
9A All machines of unit & 164Tsudakoma Air Jet with Cam 16
9B Toyota air Jet Looms with Cam, Batching 849C Toyota air Jet Looms with Cam 71
Toyota air Jet Looms with Dobby 409D Pinacol Rapier Looms with Dobby 1109E Pinacol Air Jet Looms with Cam 1109F Toyota air Jet Looms with Cam,340 cms(4 pick
insertion)150
Toyota air Jet Looms with Cam,340 cms(6 pick insertion)
50
Table 3: Different weaving units and Type of Product Manufacture
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Beam Length:
Type of Fabric Average Length(mts)
Yarn Dyed Fabric 1800
Grey Fabric 2500
Wider Width Fabric 3000
Speed & Production:
Sl. Number Type of Fabric Production in Mts/Loom/Day Speed(RPM)
1 Yarn Dyed Fabric 200 550
2 Grey Fabric 300 600
3 Wider Width Fabric 170 500
Unit Production/Day (mts)
Efficiency (%) RH (%) Count of Thread
Width of Fabric
(inches)On
LoomAt
Room1 80 80 652 80 80 653 75 80 654 22000-25000 80-85 80 65 120/2-140/2 725 34000 80 80 65 30-100 wider6 75-80 80 657 152065 80 80 65 116-1188 85 80 65
9A 43000 80 80 65 30-100 939B 80 80 659C 75 80 659D 85-90 80 659E 80 80 659F - - - - - -
Table 4: Production, Efficiency and RH of different divisions
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7.0 Preparatory for Dyeing and Printing
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Greige Fabric Processing
Geige fabric for further processing is sourced mainly from the silvassa plant (95% of the fabric processed).
The product mix available and processed:-
Fabrics by weight:-Light, medium, heavy
Fabrics by blend:- Poly Cotton, Cotton Viscose, Cotton Lycra, Cotton Spandex
Fabrics By weave:- Twill, Plain, sateen, satin, dobby, design(Jacquard)
The fabric is already graded when it is received. 2000 Steel Racks are there for storage for up to 29 lakh Meters of fabric. Average length of fabric on a A-frame batch is 4500 meters but it could vary on the GSM. Fabric Rolls are opened and converted into A-frame batches and sent for further processing of singeing and desizing.
7.1 Singeing
Singeing is the process of removal of protruding fibers. Singeing is done via gas flames which come in contact with fibers and burn them.
The fabric runs perpendicular or tangentially to the gas flames depending upon the fiber properties and thickness of the fabric.
INFRASTRUCTURE:
There are 3 machines on which these operations are performed.
The machine used is “Osthoff Senge”, Models: - VP99-H (2 m/c) & 42327 Wupputal, Germany.
Speed of Fabric:
Light fabrics: - 100 - 120 mts/min
Heavy fabrics: - 60 - 70 mts/min
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PROCESS:
The 1st phase is the pre brushing, where a brush is applied
in order to raise the protruding fiber.
The process is carried out by applying gas flame on the
fabric, for most of the fabric; flame is applied on the
either side of the fabric, for some qualities it is applied
only on the face side.
The pressure on the fabric is applied in the brushing phase
which is generally around 12 mbar.
The flame intensity could be reduced by applying the flame at a tangential angle, there are 4
angular positions.
0 represents no flame is applied on the fabric and 3 represents the fabric is applied at 900. 1 and
2 are positions in between 0 and 3, where 0, 1, 2 and 3 positions represents 12o’clock, 1
o’clock, 2o’clock and 3o’clock of a watch respectively.
The last phase is post brushing, where a brush is applied to remove the burnt fiber from the
fabric.
LEARNING:
The maximum senge intensity on a fabric could be when parameters are 20 mbar and clock
position is 3, for light weight fabric it is decreased up to 8 mbar and clock position 1.
These machines can process up to 30,000 meters /8 hrs.
In case of dobby and miletta check fabric the pre-brush pressure is 3(+/- 1).
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7.2 Desizing
It is the process of removal of starch from the fabric, mainly carried out by application of enzyme. Starch is mainly used as sizing agent while weaving so high-activation, high-stability and selective enzymes are choosen which can target on starch sizing agent.
Enzymes need to be kept active in a certain range of pH (such as pH 5 –pH 9). Mainly Aquazym PS-L Enzyme is used. In some cases Polyvinyl Alcohol (PVA) is used as size material and it could be easily desized with the help hot water.
Chemicals used in desizing Process are as follow:-
Wetting agent: - increases absorbency in fabric.
Enzymes: - required for removal of sizes applied to fabrics.
Chelating agents: - restricts the reaction of any metal ion with any added chemicals.
INFRASTRUCTURE:
This process is continuous; all the chambers are arranged consecutively in order of their purpose.
The machine has an impregnating chamber for application of desizing chemical on the fabric, a steam box for assisting chemical activation on the fabric, one foretractra chamber for the removal of excess chemical, 3 extracta chambers for washing off the chemicals and a set of rollers to dry the fabric. The temperature for washing and steam box is 950C.
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PROCESS:
The fabric moves from post singeing brush to steaming chamber is to make size material swell, inside
the foretractra, the fabric is fed into a mixture of enzyme and chelating agent, the extra chemical is
removed here only by roller pressure, the next process of removal of size happens inside extracta, here
there are 3 chambers, inside these chambers the fabric is washed with hot water. The next process is
passing the fabric though the heated chambers in order to dry the fabric, after this the fabric is batched.
Aquazym PS-L 2-5 ml/kg
Felosan APF 3-4 ml/kg
Chelating agent (Mangle Expression) 100%
Soakage temperature 900C
Stacking Time 6-18 hrs
LEARNING:
The total time for which the fabric remains inside the desizing machine is 8-15 minutes.
After desizing, the fabric loses about 7-8% of the weight. Residual size material is measured in a
unit called TEGWA, if level of TEGWA is higher, sizing is done properly and if it is lower, sizing
has not been done properly.
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7.3 Pre Treatment Range (PTR)
Fabric from desizing process arrives to the PTR and is fed into the machine. It is a composite machine range where the fabric is washed, bleached and dried before it is dyed.
The 2 processes taking place inside the PTR are scouring and bleaching, the purpose of scouring is to remove the wax, dirt and other foreign material from the fabric while the purpose of bleaching is to whiten the fabric.
INFRASTRUCTURE:
The machine is called BENNINGER PTR.
There are sections in this machine as follow:
INJECTA: Fabric is washed with water and steam.
EXTRACTA: Remove the material present inside the fabric.
IMPECTA: Padding of fabric with wetting agent, reserve and stabilizer.
STEAMER: Steaming of fabric, action of chemical on fabric.
EXTRACTA: Removal of wax and dirt from the fabric.
PROCESS:
The fabric passes from the INJECTA and EXTRACTA chambers first, where washing is done and impurities are removed, next, the fabric moves from IMPECTA chamber (Chemical Addition Tank) where it is padded with H2O2 and other chemicals, from there it passes through steamer where at a high temperature the steam is applied to the fabric and chemicals act upon the wax and impurities.
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The chemical composition in IMPECTA is like this:
Chemicals Quantity (ml/kg)
Peroxide (H2O2) 20
Reserve 4
Wetting agent 4.5
Stabilizer 4
NaOH 15
Table 5: Chemical Composition in IMPECTA
The Steaming temperature is around 950C. Here in the steamer H2O2 acts as bleaching agent
while NaOH is used for scouring, NaOH also provides a basic medium for Bleaching. After this
the fabric is dried and batched.
LEARNING:
The entire process takes 8-20 minutes to complete. The speed of the fabric is 76 m/min. scouring and bleaching are simultaneous processes. The fabric coming out of PTR is somewhat basic because of presence of small amount of NaOH. The process happening inside PTR is emulsification and Saponification and the byproducts are emulsions and wax, grease and dirt.
Neutralization is carried out many a times after bleaching if the buyer demands for it, otherwise if it is to processed further or pass through the mercerization process, it is not neutralized, Acetic acid is used for neutralization process.
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7.4 Mercerization
Mercerization is a preparatory process mainly used for cellulosic fibres when lustre is important or light shades are to be dyed. The main purpose of mercerization is to increase the absorbency, dimensional stability and luster.
INFRASTUCTURE:
Benninger Mercerizer equipped with the Ben- dimensa technology is used for the mercerization process. There are three mercerizers out of which 2 machines are based on the chain principle, while the third machine is based upon chainless principle exclusively used for heavy/bottom weight fabrics.
PROCESS:
The fabric is first passed through “Rinsing Drop” where it is padded with weak lye (40-60 GPL), then the next process is passing it through “Impregnators” where it is padded with NaOH (28-30 Be), the fabric is dipped in the solution for 35-40 sec before washing, 50-60% of the caustic is squeezed out of it, next, it is spread with water to increase the strength.
The next is the stabilizer zone that provides tension to the fabric; it is passed through 4-5 washer and stabilizer at 950C to remove the caustic matter, now it is passed through a trough containing grain acid(combination of mineral acid), used to remove the small amount of caustic material left (5-10%).
The Average processing speed is 60-70 mts/min
Chemicals used in the process for mercerization are:
NaOH (28-30 Be)
Organic acid
Caustic soda
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Features:
Mercerization is a hot process.
Cold mercerization faces the problem of non-uniformity due to highly viscous solution.
Concentration of caustic- 28-30Be, which is around 250 g/l.
Treatment temperature is 60 0C.
Mangle pressure-3.5bar.
Wet pickup-75%.
10% shrinkage during mercerization.
300m fabrics inside the machine at a time.
In chain mercerization, fabric can be elongated width ways after mercerization.
LEARNING:
The fabric shrinks in this process because of the rounding of fibers from kidney shape to circular
form and because the caustic decreases the hollow space between the yarns, lusture increases
as a result of this process.
A denser fabric would have a lower shrinkage than a non denser fabric.
WIDTH ENTRY BEFORE CHAIN AFTER CHAIN EXIT
Cms. 150 149 152 146
Table 6: Reduction in Width due to Mercerization
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8.0 Fabric and Yarn Dyeing
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Dyeing
Cold pad batch (Reactive) – Cotton Fiber.
Pad dry pad steam (Reactive, VAT) – Cotton and PC blend.
Disperse on thermosol & reactive on CPB – PC Blend.
Disperse vat single bath – PC Blend.
E control (Reactive) – Cotton Fiber.
8.1 Cold Pad Batch
The cold pad batch machines are used for applications of only reactive dyes. There are three cold pad batch machines from benninger known as kusters dye pad.
The color requirement of a fabric is directly dependent on the following:
The length of the fabric to be dyed
The pickup of the fabric in percent
The GLM of the fabric.(Gram per linear meter)
Dyeing process takes around 16 hrs for dyeing at room temperature. It can produce a range of light, medium and dark colours.
CPB has a vertical arrangement of rollers for dipping the fabric in dye solution. The number of rollers may vary from 2 to 4. This operates in a range of 50-60 mts/min. The dye to chemical ratio may vary but standard ratio used is of 4:1
The various chemicals used in the dyeing trough are:-
Fixer chemicals - Sodium silicate used for fixing
Reactive dyes
Soda and caustic
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After impregnation of the dyestuff the finishing rollers and squeezing unit squeeze out the extra dye solution. These batches then require fixation dwell time for which the batches are kept under rotation (to avoid any leaching out of any dyestuff) in the RFD storage generally for 16 hrs.
Each machine has 3 dye and 2 chemical tanks with each having a capacity of 800 lts. Approx production is 20,000-22,000mts/8 hrs.
8.2 Continuous Dyeing Range:
The Monforts Thermosol is a continuous dyeing range in which the pre-treated fabrics acts as input and a completely dyed fabric is received at the output which is then sent for finishing. This is mainly used for the following types of dyes:
Disperse
Modified Vat Dye
Reactive
There are 2 monforts thermosol which have similar construction and only differ in the number of IR dryer Chamber which one machine has a single unit while the other has two, requirement of dryers depends upon the application required.The machines have a Thermex hot fuel chamber which has 28 rollers in 3 chambers.
The fabric is fed through the Feeding section which then passes into the Wetting unit where it is dipped in the alkalis required for dye fixation and dye solution are present as required. The fabric then passes on to air passage rollers that assist the penetration of dyes after which fabric pass into the IR dryer units where through heat of the IR burners partial or pre-drying is performed where up to 40% of the moisture is removed.
Temperature is maintained at 450C, the fabric then passes into the Thermex hot-flue where the measuring and control unit (chamber atmosphere) control the temperature and the Steam injection unit provides steam for heating the chamber. After the curing process the fabric is completely dyed and received at the Outlet section. The speed of the machine varies from 45-50 mts /min and generally runs at 25-30 mts /min at an average.
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Benninger Thermosol:
The Benninger thermosol is mainly used for
Vat dye
Reactive dye
Disperse dye
The machine is mainly based on the working process principle of pad dry pad steam method in which the dye impregnation and drying is done on the thermosol while the pad steam/curing is performed on the Benninger pad steam machine.
The fabric is fed into the machine by various rollers a scray. The fabric subsequently enters the dyestuff trough where it comes in contact with the dye solution, application method used is of single dip single nip. Then it passes through an intermediate air passage which assists in the dye penetration and then passing into the IR dryer unit for the purpose of pre drying which composes of 3 units and 3 burners heated at gradually increasing temperatures up to 4500C.
The pre drying process helps in removal of up to 40 % of the moisture. After pre-drying the fabric enters the thermfix hot fuel chamber in which the fabric is passed and dried at high temperature and high pressure, thus resulting in a completely dried fabric as the output.
To constantly provide dyestuff solutions there are 5 storage tanks of which 4 are dye tanks and 1 is of chemicals of 4 with capacities ranging from 500-1500 liters.
The dye: chemical ratio thus is maintained at 4:1 at an average.
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8.3 Benninger Pad Steam Machine
The pad steam machine lies in line with the thermosol machine for completion of the PDPS (Pad dry Pad steam) process. The Benninger pad steam machine is basically used for the following purposes:-
Colour development
Reduction clearing in case of blended fabric double bath dyeing.
There are 3 Benninger pad steam machine is available for the above said objectives. Dyes which are processed in the pad steam machine are:-
Reactive dyes
Vat dyes
Chemicals used for reactive pad steam process are:-
Salt
Soda ash
Caustic
Chemical for vat dye pad steam process is: - caustic hydro.
The fabric is fed through feed rollers into the chemical trough where alkali for fixation chemicals for reduction clearing are applied on the fabric through single nip single dip method after which it passes into the booster chamber where the special squeeze nip of the booster guarantees a uniform pickup, independent from production speed and fabric weight. The fabric then moves into the recta chamber with rollers where steam treatment is given to the fabric at high temperature and high pressure.
After which the fabric passes on to the extracta chambers. There are 9 extracta chambers that are used for the purpose of soaping, washing, neutralization and reduction clearing. In first two extracta chambers washing takes place at room temperature. In the following two chambers H2O2 for oxidation is added at 600C.In the next 3 chambers soaping and hot wash is done. In the concluding 2 washing chambers hot wash with neutralization is at 90-950c degrees. The delivery customer cylinders nip out any moisture in the fabric with steam heated cylinders and fabric is received in dried condition as output. The processing speed at an average is 50 mts/min.
8.4 Dyed Fabric Washing
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The machine has in total 9 chambers in which2 initial extracta chambers are for rinsing purposes and I chamber for application of the required chemicals during processing next5 chambers are the washing setup which is used for washing after the dyeing . The soaping is done in two ways:
Cold Pad Batch Wash
Cold Wash
Cold Pad Batch Wash:
Dekol fbsn and acetic acid mixture is used for dyed fabrics from cold pad batch thefabric is first set for relaxation and passed through the heated chambers given as under
The fabric is treated with water at 30OC, then treated with water at 400C, then a soap solution of DECOL FBSN and acetic acid is applied at 600C, Normal washing with water at 900C takes place in the next 5 chambers, Green acid of neutralizes the fabric at 80ocin the last neutralizing chamber.
Cold Wash:
Cold wash is given to fabrics coming direct from the continuous dyeing range. The fabric is passed through the heated chambers given as under. The fabric is treated with water at 300C.It is then treated with water at 40OC.
A soap solution of Arieanal +acetic acid is applied at 500C.Normal washing with water at 500C takes place following which green acid of 160 gpl neutralizes the fabric at 500C. The maximum speed of the machine goes up to 40 m/min. The second washer has drums in its extracta chambers which are also known as Trikoflex; this makes it preferable for medium weight and light weight fabric.
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8.5 Yarn Dyeing
MATERIAL FLOW
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Package Winding
Pretreatment
Dyeing
After Treatment
Moisture removal (Hydro Extraction)
Winding
Drying (RF dryer)
Soft winding
96 spindles on each side
Speed varies with count:-
I. 40 count -700 rpm
II. 60 count- 850 rpm
Package density- 340 g/l
Tension in weft yarn package is kept higher than warp yarn package
Automatic splicing of broken ends
Yarn dyeing:
Weight of machines (kg) No. of machines
1 4
25 4
54 5
243 3
325 2
535 1
1070 2
Table 7: Capacity of machine in terms of weight of yarn.
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PRETREATMENT
At 100 0C for 45 min
CHEMICALS
Bio scour super plus - Scouring agent
Lanapex - Sequestering agent
Caustic soda
H2O2
Biocatalase - Peroxide killer
Aeronil - Leveling agent
DYEING
60- 80 0C for 40-60 min
Depsodye MSDA ----- leveling agent
Soda ash
Caustic soda
AFTER TREATMENT
Soaping at 95 0C for 15 min
Ecopret AS ----- soaping agent
Perifil 210 ----- cationic agent
Ecofix NF ------ fixing agent
In to out cycle time ---- 3 min
Out to in cycle time ---- 4 min
M.L.R. :- 1:8
Fully flooded machine (HTHP)
Packages are hydro- extracted after dyeing to remove the excess liquor. This is done by centrifugal force.
Drying is then done in RF drying ranges.
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Uneven dyeing may occur due to following reason:-
Improper temperature control.
Non-uniform liquor flow.
Uneven winding tension.
Blocking of perforations.
Improper dosing.
Types of Dyeing
I. REACTIVE DYEING
DEPTH SALT (g/l) SODA (50 %) CAUSTIC (ml/l)
<1 % 20 10 1
1-3 % 50 5 1
3-4 % 70 5 1
4-5 % 80 5 1
>5 % 90 5 1
Black 100 5 2
II. HE dyes
DEPTH SALT (g/l) SODA (g/l)
<1 % 20 10
1-3 % 50 15
3-4 % 70 20
4-5 % 80 20
>5 % 90 20
Black 100 25
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III. VAT DYEING
DEPTH CAUSTIC 50%
(ml/l)
HYDRO (g/l) SALT (g/l)
<1 % 14 6 8
1-3 % 18 8 13
3-5% 22 11 18
>5 % 26 13 22
Laboratory Testing:
Light Fastness
Wash Fastness(gyro wash)
Crock meter for rubbing fastness
Multi precise yarn dyeing machine with magnetic pumps. There is no into out and out to in flow
200 kg capacity
Package winding machine of about 100 kg
Knitting machine
I. For sample dying
II. To check package to package variation
12 tonnes per day production
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9.0 PrintingPrinting is the textile processing technique for localized application of dye/pigment is a desired pattern /design.
The styles of printing are carried out are reactive, discharge (white and colour), and pigment. The printing section has its own design studio and colour kitchen for screen, dye/pigment solution development.
The studio is responsible for the designing of the designs for screens which are required to be developed in accordance to the design specification provided by the buyer.
There are 5 workstations which are equipped with Ramsete III version 8.33 for design development. Screen preparation department is the provided by the ready designs and its specification for the preparation of screen.
Screen Engraving:
After receiving the design developed for screen, work in the screen preparation starts with the engraving. Nickel made Fine mesh ready screen of varying circumferences of 640mm, 819mm and 914 mm are available .CST Inkjet printing unit is used for the purpose of engraving.
Coating of the screens is done with the combination of three constituents namely, Photo emulsion (readymade liquor), Dichromate and Distilled water which is done as per the design The design development is done through the ink when the screen is exposed to uv-light ,coating hardens to retain itself and then washing in reggiani screen washing machine to wash off the undried ink, thus the inked part becomes the area of penetration for the color pigment in the rotary screen. Thereafter the coating on the screen is cured in the embee curing machine for 2 hrs at 100°C. After which the screens are finally dried in the femate Climatizer.
The screen preparation department also houses Mimaki Textile Inkjet is the machine used for digital printing. Digital printing is done at a very small scale for only special purposes. Any type of fabric can be printed upon using this machine. Approximately 60 million colors can be printed using this machine. Ripmaster is the CAM used for controlling these machines operations
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AUTO COLOR KITCHEN
Auto color kitchen is responsible for making the paste for printing by using various chemicals & dyes and regularly supply the machines as required.
The kitchen has 5 silo storages for urea (hygroscopic agent), sodium bicarbonate, Potassium carbonate used for reactive printing paste, Resist salt (oxidizing agent), soda ash. The silos supply to the automatic prepeartion unit (1000 lts) for paste preparation.
Key Ingredients for printing paste are as follow:-
Binder: - 18% binder is used for dark shade.6% binder is used for lighter shade.
Luprimol (STG) - It act as softner which reduces hardness of the water and paste soft.
Lutexgel(HIT) - It act as thickner to make viscous paste of the dye.
Fixing agent(LF) -It act as fixer & rubbing fastness will increase.
Rongolite (ST) -It act as reducing agent for white and color discharges.
For 100 % cotton fabric sodium sulphoxylate is used, for blended fabrics ZincSulphoxylate is used.
There is a roto mix machine for the colour preparation which is dosed by chemical by various dosing systems which prepare the colour paste in large open tubs which are transported to the machine for dosing the paste to the screens.
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Textile Printing
The Textile printing practised at Alok is the rotary screen methods for which there are3 Reggiani rotary printing machines, 1 Lakshmi rotary printing machine and a sample printing machine from Reggiani. In addition to this there are Two Airoli Loop Agers that are used for the purpose of curing.
Preparation of cloth for printing:
The wet preparatory processes are all carried out on the Benninger PTR where as for knits it’s done in the Sclavos soft flow machines. Apart from wet preparations the cloth is brushed & sheared on lafer shearing machine by being passed over rapidly revolving knives arranged spirally round an axle, which rapidly and effectually cuts off all filaments and knots, leaving the cloth perfectly smooth and clean and in a condition fit to receive impressions of the most delicate engraving.
Some figured fabrics, especially those woven in checks, stripes and crossovers, require very careful stretching and straightening on a stenter frame, before they can be printed with certain formal styles of pattern which are intended in one way or another to correspond with the cloth pattern. Finally, the cloth is wound around a hollow woodenor iron centers into rolls of convenient size for mounting on the printing machines.
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INFRASTRUCTURE
A rotary printing machine prints designs with engraved designs on a curved cylinder. Substrate here is a continuous fabric roll which is to be printed and further modified if required (e.g. die cut, overprint varnished, embossed).
The initial development of the samples is done using CAD in the studio using which the screens are developed after which the Reggiani sample printing machine is used for preparation of samples. The normal width of this machine is 70”. It can be extended up to 120’’.
Laxmi Rotary Printing Machine
Up to 12 colors design can be printed in this machine. The screens are mounted on the screen stations provided, for each color in the design a screen is used with the color paste being provided into the screen through a pipe and a squeeze arrangement within the screens apply pressure to enable printing paste penetration.
The fabric is fed through rollers to the printing table and is stabalized in width by a guiding system .As the fabric passes under the screen rollers the colors are applied as per design. The capacity of this machine is 20 to 100 meters/seconds depending upon factors like design and the number of colors in that design and the types of the fabric (coarser takes less time as compared to finer fabric).
The machine is pre-equipped with the under-bed washing and drying unit which cleans and dry up the belt after each cycle. After printing rollers, the drying unit dries printed fabric in a 5chamber arrangement dedicated for drying. After drying, the fabric is sent to the polymerizer for fixation, i.e. the fixing of dyes /pigments.
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Reggiani Screen Printing Machine
There are 3 Reggiani rotary printing machines out of which 2 machines can print upto 12 colors and the third machine can printupto 14 colors. The Reggiani screen printing range is has similar operation run as that of the Lakshmi rotary printing machine.
The only difference in both the machines is the application of glue in the Reggiani machine by a glue roller that ensures that the fabric sticks to the running conveyor belt as it passes under the various screen rollers for coloration.
After printing it enters the heating chamber where there are 5 chambers that dry the printed fabric with high temperature and pressure. Two machines out of three have the dryer in on-line position where as the third machine has an dryer in over head position. The dried fabric received is then received in a batch form or plaited (preferable) and then sent for curing.
Technical details of Reggiani Rotary printing machine
Number of colors 12 & 14(max 24 colors)
Printing speed 30 to 45 m/min max(90 m/min)
Printing width 72” to 80”
Multi repeat printing heads (screen size) 640 to 1200 mm
Squeegee system UNIFLUX continuous magnetic field
Table 8: Technical Details of Rotary Screen Printing
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10.0 Finishing
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10.1 Stenter
It is used for: -
I. Emulsion padding for MXL
II. For OBA application
III. For heat setting
Both pin and clip arrangements are used
Oil heating mechanism for drying
7 chambers in stenter.
Bowing and heading rollers at the feed end to remove creases.
Overfeed: -5%.
Fabric speed: -50m/min
PROCESS:
CHAMBER NO LIGHT SHADE MEDIUM SHADE DARK SHADE
1 110 0C 110 0C 110 0C
2 120 0C 120 0C 120 0C
3 130 0C 130 0C 130 0C
4 140 0C 140 0C 140 0C
5 140 0C 140 0C 150 0C
6 140 0C 140 0C 150 0C
7 140 0C 140 0C 150 0C
Defects:
Pin holes
Yellowing
Oil spots or soiling
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10.2 Sanforising
It is pre shrinking finishing
Rubber belt shrinks the fabric along with it
Speed 50 m/min
Steam heated roller over belt at 110 0C
50 m fabric from in to out
After shrinking zone, there is a setting zone to set the shrinkage in fabric
Fabric is cooled and then batched
Some shade variation may occur
10.3 Calendering
Fabric speed of 70 m/min
Expander rollers are used at feed end
3 roll system with 2 cotton rolls and one steel roll
Temperature of calendars roller is 70 0C
Pressure 70 N/mm
Strength reduces after calendaring
It improves the feel and surface appearance of fabric
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10.4 Microsanding
Rollers with diamond Amery pile
Two pairs of rollers
Rough- 220 grades
Smooth- 400 grades
24 rollers
Lower grade, higher toughness
220 grade rollers move opposite to the direction of fabric
400 grade rollers along the direction of fabric
Defects:
Pitch variation
Batching (tension variation)
Creases
CS
Speed - 46 rpm
Fabric speed -10 m/min
Tension onto roll -50 kg
10.5 Brushing
Fabric speed - 199.6 m/min
24 small rollers over a big roll
Speed of rollers -110 rpm
Pile speed -125 rpm
Counter pile speed -115 rpm
It improves softness of the fabric
Both back and face abrasion/brushing is possible
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TAPE USED IN PACKING
Black – Roll will go to finishing.
Red – Minor defects and it will again go for inspection.
Yellow – Printing defects and it will for inspection for rectification.
A, B, C is the type of coding used to identify the party.
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11.0 Testing and Inspection
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Textile Testing
Textile testing refers to all the testing processes involved in fabric manufacturing, it ranges from fiber testing, Yarn testing, Fabric testing and testing processes involved in Dyeing and Printing.
Whenever an order is confirmed, it takes 1 day to analyze it at Alok Industries Ltd., the analysis is done at testing lab, and the main parameters considered in the sample are as follow:
Material Warp Count Weft Count EPI PPI Weave Type Feasibility
11.1 Yarn Testing:The main parameters tested in a yarn are as:
Count Strength – in Pounds Imperfections: thick and thin places Strength : RKm (Resistance/Km) CSP : Count strength product U Percentage : Uniformity
If RKm of a yarn is higher, the yarn has higher strength and if it is lower the yarn has a lower strength.
CSP: it says that for a yarn of particular count at what strength applied the yarn breaks down.
If U% is higher, the yarn has a lower quality and there is a lot of non- uniformity, but if it is lower the yarn is considered to be more uniform and of higher quality.
Amount of Material to be inspected is as follow:
Order Quantity No. of Cones to be inspected Upto 100 kg 2 cones100-1000 kg 5 cones1000-4000 kg 10 cones4000 kgs and above 15 cones
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Machines used for yarn testing are as:
Wrap Reel: the main purpose of wrap reel is to identify the count of the yarn.
Cones:Reel = 1:3
Speed of machine is 120 RPM, Length of ‘lea’ is known and accordingly the count is measured.
Electronic Twist Tester: The machine measures the TPI (twist per inch) in the yarn.
Board Winder: it is a wooden board kind of testing equipment on which the yarn is winded, it determines the imperfections like thick and thin places, Neps etc. if on the board there is uniformity and even distribution, it means that there are lower defects in the yarn and it has a higher quality.
Uster Tester: It is an advanced testing machine by ‘Uster Technologies’, it displays different Yarn parameters on a monitor like:
U percentage CVm Number of Neps Hairiness Foreign Matter
Uster Tensojet: This Testing equipment mainly deals with Tensile strength and effects on yarn on the application of force in lengthwise direction. The machine can be used to check parameters like:
Tenacity (RKm) Strength of yarn Breaking Force Elongation
For combed cotton yarn of 30’s count tenacity should be more than 20 RKm.
Uster Classinat Quantum: this testing equipment which is a fully automated determines the slub and color contamination, it works at a very high speed of almost 500 Mtrs/min. On a testing parameter it classifies the defects in following categories:
0 – 1 Nep1 – 8 Slub (short thick)8 – 32 Slub (long thick)
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Figure: Wrap Reel
11.2 Fabric Testing:
The main parameters tested on a fabric are as:
Width Variation EPI PPI GSM Tearing Strength Imperfections like thick, thin places
If GSM of a fabric is lower the tensile strength of the fabric is lower. The roll to roll width variation is around ½ to 1 inches, while inside a roll width variation tolerance is 1 cm, the main reason for width variation in roll is the pre-treatment processes and dyeing, width variation is minimal in case of greige fabric.
Machines used in fabric testing process are as:
Tensile Strength: ASTM 5034 (Titan2 machine), Sample size: 250 * 100 mm2
Tearing strength: ASTM 1424 (Elmatear Machine), Sample size: 100 * 63 mm2
Pick Glass: For EPI and PPI calculation
GSM Tester: To calculate the GSM of the fabric
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11.3 Defects Found in Inspection Department
Specifications & Appearance Weaving Related DamagesCover
Bumping Ball Formation Reed CutReediness Black Stain Selvedge Without LenoNeppiness Broken End Short PickHazyness Broken Pick Sizing Patches/ CrystalUnevenness Bump Mark Sizing StainStreakiness Broken Pattern Slack EndKitty Level Design Change Slough OffFringe – Less than 4mmSelvedge – 6mm - 8mm
Design Cut Slackness
Dyeing Related Damages Double End SnarlingPatta Double Pick StainShade not Matching Temple Mark Loose PickShade Variation Fine End Temple cutUneven Dyeing Hanging Thread Weft BarStreaks Starting Mark Weft DistortionSpinning related Damages Thin Places Wrong DentingCoarse Pick Thick Places Wrong DrawingCockled Yarn Knots Wrong PatternColor Contamination Lashing In Wrong WeftCount Variation Leno Cut Yarn Lot ChangeDirty End Less Width Reed markDouble Weft Let Off Mark Take off MarkHigh Twist Yarn Lighting Starting Mark Dobby lineKnots Light thick place Jumping EndMoire Effect Loom Fly FloatingNeps Loops Wrong EndOily Weft Loose Leno Binding SmashSlub Mending Impression Partial DefectSlubby Weft Missing End CrackUneven Weft Yarn Nozzle Mark HoleThree Ply Oily Stain FloatCoarse End Pulled Warp Multiple Breakage
Rust StainSizing Machine StopsTorn FabricTear DropStitches
Table 9: Manufacturing Defects in Yarn and Fabric
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Grey Fabric Inspection
Four Point American System
Sl. No. Damage Length Point Count1.0 Weft Wise
1.1 0.1” - 3” 11.2 3” - 6” 21.3 6” – 9” 31.4 9” and above 4
2.0 Warp Wise2.1 1/25th of the length 4
3.0 Partial Defect3.1 =< 5 mm 2
Table 10: Four Point Fabric Inspection System
Note:-
All color foreign matter should be removed. All partial defects more than 5 mm should be cut.
Quality/ Grading (for minimum 5000 meters shipment).
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Grey Fabric Grading & Inspection
Marketing/Grade
Pts./100 sq. Mtr. Pts./ 100 Linear mtrs (Normal Width)
Pts./ 100 linear meter (Wider Width)
Fabric Length
A 15 24 45 >20 mtrs for domestic>40 mtrs & above for Export
B 22 35 67 >20 mtrs & above
C 31.25 50 95 >20 mtrs & above
D No bar <10 mtrs >1 - <5 mtrs >1 mtrs - <10 mtrs
E No bar >11 - <20 mtrs >5 - <20 mtrs >11 mtrs - <20 mtrs
F All continuous Defect (warp + weft)
No bar All continuous Defect (warp + weft)
>20 mtrs and above
G 47 75 nil >20 mtrs and above
Table 11: fabric Gradation Chart
Note: - All remaining qualities less than one meter will be designated as under
Market Length PackingChindi 0-25 cm in kgFents 25-99 cm in kg
Formula:
Points per 100 sq. meters. = Total points * 39.37 * 100
Width / Total Meters.
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Conclusion
The textile internship has been completed in Alok Industries Pvt. Ltd, The duration of the
internship was of two weeks where we had covered spinning, preparatory processes for
weaving, weaving, polymerization, preparatory processes for dyeing, dyeing and printing, yarn
dyed sections and finishing sections. We studied the various aspects of a textile processing unit
starting from its grey section to the functionality of the various departments.
We were introduced to the various brands of machineries available for carrying out the
different textile processes to meet global standards. The internship helped us to understand
the structural and functional constituents of the industry and also adapt to real industrial
situations which equips us for decision making in a realistic environment
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