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BRANDIX COLLEGE OF CLOTHING TECHNOLOGY
REPORT ON
DYEING AND FINISHING
MILL VISIT
Course title; College Diploma in Clothing Technology
and Management.
Visited factory; BRANDIX TEXTILE LIMITED.
Visited date ; April 07, 2011.
Submitted by ; Nalaka Sampath.
Submitted date; May 06, 2011
Contents
Acknowledgement ........................................................................................................................................ 1
About Brandix Textiles Limited, Makandura................................................................................................. 2
The flow chart ............................................................................................................................................... 3
Greige fabrics ................................................................................................................................................ 3
Inspection for greige fabric ....................................................................................................................... 3
Pre-treatments .............................................................................................................................................. 4
i. Cleaning out impurities ..................................................................................................................... 4
a. Scouring......................................................................................................................................... 4
b. Bleaching ....................................................................................................................................... 5
c. Desizing ......................................................................................................................................... 5
ii. Property improvement ..................................................................................................................... 6
a. Singing ........................................................................................................................................... 6
b. Mercerizing ................................................................................................................................... 6
The dyeing machines in BTL .......................................................................................................................... 7
i. Continuous Dyeing Range ................................................................................................................. 8
ii. Jigger Dyeing machine. ..................................................................................................................... 8
iii. Jet Dyeing machine ........................................................................................................................... 9
iv. Cold Pad Batch machine ................................................................................................................. 10
Lab Testing. ................................................................................................................................................. 11
Finishing ...................................................................................................................................................... 12
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Acknowledgement
I present this report on mill visit on textile dyeing
and finishing, Brandix Textile Limited Makandura.
For this report I extremely thankful to
Ms. N Gamage and Dr. R U Kuruppu, who guided and advised
us during the mill visit.
And also I thankful to the talented people working at
BTL, who helped us and fully indulged us to study the mill process.
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About Brandix Textiles Limited, Makandura.
Brandix Textiles is Sri Lanka's largest woven fabric manufacturer, specializing in fabric reactive, vat, pigment, sulphur and pad-dyed cotton and cotton-lycra. Made to unsparing standards, its dyed and printed products reach South East Asian, Mediterranean, South American and now South Indian markets. While more than 60% of its customers are external customers, Brandix Textiles provides more than 50% of the Group's woven fabric requirements.
Its revolutionary innovation in textile technology is a result of its strong Research and Development focus and has brought it a reputation for excellent quality and cost effectiveness. The company achieved a national milestone last year when its Makandura woven textile plant became the first locally to receive Fair trade and Organic certifications from the Institute for Market ecology (IMO) of Switzerland.
The GOTS certification is the next step for Brandix Textiles is the definitive global certification for organic textiles and covers the production, processing, manufacturing, packaging, labeling, export, import and distribution of all natural fibres.
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The flow chart
Greige fabrics
BTL buys greige fabric from different countries, mostly from south Asian
countries like Pakistan and India. The quality of the fabric is varying according to the
supplying country.
In the greige fabric department of BTL, inspection of fabric is done. Accepted
fabric is send to the next process.
The used inspection method for greige fabric in BTL is,
one in ten point American system.
Inspection for greige fabric The main purpose of the inspection is to check the Greige fabric for
identify the faults. The faults of a woven fabric can be identify as;-
Weaving faults. Mechanical faults. Yarn faults. And Other faults
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In a textile mill there are so many important processes before a textile product
coming out from the mill. In addition to dyeing, there’re some processes involved with
this dyeing process. Those are;
1. Pre-treating.
2. Dyeing.
3. Finishing.
Pre-treatments “Pre-treatment” is the preparation of textile material for dyeing. The purpose of
this process is to improve the properties of fabric, with minimum damage to the fibres of the
fabric. And the cleaning off dirty partials on fabrics is the next purpose of this process.
i. Cleaning out impurities
As we saw in the factory, fabrics come as raw materials are containing some foreign particles. Those are labeled as impurities of the fabric.
In the BTL, used methods for remove containing impurities of fabric are ;-
a. Scouring.
Woven fabrics contain about 8 to 10% of natural impurities and they carry additional 5 to 7% of the seizers. Scouring is the process done for removes those material impurities of fabrics. The natural Impurities require treatment with strong alkalis like caustic soda at high temperature for their breakdown and dispersion in water.
In BTL, this type of machine is
used for the scouring process.
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b. Bleaching
Natural fibers are yellowish or off-white in color
due to color impurities presence in the fiber.
These are defined as unsaturated compounds,
such as amino compounds. Bleaching therefore
can be defined as the destruction of these color
bodies.
Natural coloring matter that are ultimately removed by oxidizing agents (by oxidizing agents or reducing agents). The oxidation treatment or bleaching is necessary for producing white goods as finished products
or product for dyeing. Bleaching improves the brilliance and evenness of the shade. Bleaching is normally carried out with hypochlorite, hydrogen peroxide or sodium chlorite.
c. Desizing
Desizing is called as removing Starch from the fabric which are added to keep the straightness of yarns in weaving. Desizing is reverse of sizing. Its main objective is to degrade size into soluble product so that after washing sizes remove from fabric. Among the many of desizing methods, BTL is using the enzymes desizing method. Preparation of the desizing solution
First of all wash the tank. The tank fills by water First of all salt is added, and then detergent, then desizer is added.
Note: After desizing the fabric batcher is kept for 6-8 hours in rotation to keep the desizer within the fabric. It is so because bacteria produced by enzymes take some time to eat starch. The PH is maintained from 7-8 and the RPM usually keeps 100.
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ii. Property improvement
a. Singing
When the fabrics come from the loom it has small fibres which are extruded from the fabric, called fuzz. It must be removed by singing process. In a textile mill there would be many methods of singing. In the BTL Makandura, the method for singing is gas singing, by the help of gas burners.
This machine contained two
flames. The burning flame is
coming out from the narrow hole
of the machine vertically. The
fabric runs swiftly simply touching
the flame, then the projecting
fibres are burned out without
burning the fabric. The speed of
running fabric and the length of
the flame is carefully maintained here. This flame is created by using gas, that’s why
it got this name Gas Singeing Machine.
Importance of singing ;- Singing helps to minimize or reduce the pilling effect. Pilling gives harsh or bed look to fabric. It must remove from fabric to get good quality
b. Mercerizing
Mercerizing is done for gain up the quality of the fabric before it sent to the
dyeing process.
In this process cotton is immersed in a solution of NaOH then NaOH
penetrated in to the fibre. Then NaOH is washed out completely by an acid like sulphuric.
After mercerizing fibres become cylindrical and free from twists.
To increase the luster cotton must be prevented from shrinkage. This can be achieved by stretching the fabric.
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Shrinkage of the fabric can also controlled by mercerization.
Above pictures show what kind of a machine is used in BTL for
mercerizing.
The dyeing machines in BTL
In BTL and also in other textile dyeing plants, there’re number of dyeing methods are
used for dyeing fabrics. Those are;
Reactive dyeing.
Vat Sulphur dyes.
Pigments dyeing.
Acid dyeing.
BTL uses four dyeing machine in their dyeing plant.
I. Continuous Dyeing Range - CDR (Pad Dry Pad Steam - PDPS)
II. Jigger (jumbo) Dyeing machine.
III. Jet Dyeing machine.
IV. Cold Pad Batch machine. – CPB.
In BLT jigger is used to add bluing agent also.
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i. Continuous Dyeing Range
The continuous dyeing range is suitable for small or large batch of continuous
dyeing. It is highly efficient and operates in a low fabric tension. The machine is
suitable for different kind of fibres in woven fabrics, such as cotton, and pure
polyester fabrics.
Important feature of CDR
Dye padder. Infra-red drier - The fabric dried out their moisture, when they passed
through this zone. Hot flue Drier - The fabric is subjected to heat treatment gradually to dry
or dye fixation depending on the machine configuration. Chemical padding section: - For reactive dye in chemical padding
section.
ii. Jigger Dyeing machine.
Jigger machine is suitable for dyeing of woven fabrics, up to boiling
temperature without any creasing. This machine is one of oldest machine used to
dyeing as well as for adding FBA to fabrics. Jigger exerts considerable lengthwise
tension on the fabric and is more suitable for the dyeing of woven than knitted fabrics.
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In jigger machine, fabric is dyed in its
open or full width, then there’s no fault
occur on creasing during the dyeing.
This machine consists of a small tub and
two rollers located above the dye bath.
Tailing effect also have minimized in this
machine.
Advantages of jigger dyeing machine
Low consumption of water. Short dyeing time. Can be easily operated at high temperatures and pressure Comparatively low liquor ratios. Fabrics are handled carefully and gently.
iii. Jet Dyeing machine
In this dyeing machine tension on fabric have disease as much as possible.
And also by using this machine, dyeing process can be done from relatively small
amount of dye solution.
In the Jet dyeing a closed tubular system exists where the fabric is placed. For
transporting the fabric through the tube a jet of dye liquor is supplied through a
venturi. The Jet creates turbulence. This helps in dye penetration along with
preventing the fabric from touching the walls of the tube.
As the fabric is often exposed
to comparatively higher
concentrations of liquor within
the transport tube, so little
dye bath is needed in the
bottom of the vessel. This is
just enough for the smooth
movement from rear to front.
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Advantages of jet dyeing machine.
Less water, less energy, and less chemicals are wanted.
High efficient and production.
Ideal for both knitted and woven fabric.
iv. Cold Pad Batch machine
The technique used in pad-batch dyeing starts with saturating first the
prepared fabric with pre-mixed dye liquor. Then it is passed through rollers.
The rollers effectively force the dyestuff into the fabric. In the process, excess
dye solution is also removed. After removal of excess dyestuff the fabric is
subsequently "batched". This batching is done by either storing it in rolls or in boxes.
It takes a minimum of 4-12 hours. The batches are generally enclosed by
plastic films. This prevents absorption of carbon dioxide and water evaporation.
Finally as the reaction is complete the fabrics are washed.
Advantages of jet dyeing machine.
Very efficient Liquor Flow. No harm to garments Structure. Uniform Pathless dyeing.
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Lab Testing.
Brandix Textile Limited has a very well prepared and enlarged laboratory. BLT has much type of modern textile testing instruments. Some of the important testing equipment in BTL are;- Tensile strength tester:
The tensile strength test is a modified grab test for determining the breaking strength and elongation of fabrics.
Digital Tear Tester:
Tearing Tester is an Instrument for
determination of the average force required to propagate the tear starting from a cut point of a fabric.
Simply select the unit of measurement and the number of plies. The test results are displayed digitally. No calculations are required.
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Light box
Light box provide condition of standard colors
checking in textile laboratory. Inside of the box is
painted with special grey color for without any
reflection.
Spectrophoto meter
Spectrophotometer is a device for measuring light intensity of fabrics, which can measure intensity as a function of the color. This helps to identify the colour of textile material and other parameters, and then we can make another fabric from a colour of sample fabric.
Automatic dye liquor system
This machine is using for check the dye recipes and mixes
the dyes in sample stage.
Finishing
Finishing is an important process, which give the final property improvement for a
fabric. Chemical and physical treatments are done to achieve the final qualities and
it’s gave a totally difference to fabric after the finishing.
In BTL finishing for fabrics is highly maintaining and
there is samples available for the checking their quality.
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