NATIONAL INSTITUTE OF FASHION TECHNOLOGY
2012 Textile Internship Report Arvind Naroda
By:
Vishakha Chopra 8/17/2012
The document contains the report for a ten day internship at Arvind Mills , Naroda plant
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ACKNOWLEDGEMENTS I would like to thank Arvind, Naroda unit for giving me the opportunity to undergo a training in the textile department and for extending their support towards us all throughout our internship I would also like to thank NIFT, Mumbai for giving us this opportunity and facilitating our internship It was a great learning experience throughout to see one of the most well planned and advanced textile units. We take the opportunity to thank all the people who guided us through the entire process and made our training a success by sharing their knowledge. I would like to thank Ms. Milli Das, Sr. H.R. at Arvind, without whose support and guidance the internship couldn’t have been completed satisfactorily. I am also grateful to our College mentor Mr. Ranjan Saha for guiding us at every stage and making this project a success Vishakha Chopra
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TABLE OF CONTENTS I.
Project abstract ............................................................................................................................................ 5 Aim: ........................................................................................................................................................................ 6 Course Of action:............................................................................................................................................... 6 Indian Textile Industry: ................................................................................................................................. 8 Introduction to The Company ..................................................................................................................... 9 About the company: ........................................................................................................................................ 9 Board of Directors: ....................................................................................................................................... 10 Company’s vision........................................................................................................................................... 12 Arvind denim division: ................................................................................................................................ 13 Major international buyers: ...................................................................................................................... 14 Arvind’s Brands for Denims: ..................................................................................................................... 15
II.
PPC Department ........................................................................................................................................ 18 Costing: .............................................................................................................................................................. 19
III.
Production Process: ............................................................................................................................. 21
1. Spinning Department: ......................................................................................................................... 22 Blow room: .................................................................................................................................................. 25 Carding: ........................................................................................................................................................ 29 Drawing ........................................................................................................................................................ 31 Roving ........................................................................................................................................................... 31 Spinning: ...................................................................................................................................................... 32 2. Warping Department........................................................................................................................... 35 3. Dyeing Department: ............................................................................................................................. 40 SLASHER DYEING (SUCKER MULLER)............................................................................................. 42 ROPE DYEING............................................................................................................................................. 46 4. Sizing Department ................................................................................................................................ 51 5. WEAVING ................................................................................................................................................. 53 Weaving Department (Arvind Mill) ................................................................................................. 57 6. PROCESSING /FINISHING .................................................................................................................. 59 VII.
Quality assurance .................................................................................................................................. 65
Page |4 Inspection: ....................................................................................................................................................... 66 Testing ............................................................................................................................................................... 69 Phisical Testing: ........................................................................................................................................ 69 Shade testing: ............................................................................................................................................. 70 Chemical testing ........................................................................................................................................ 71 Packaging Department: ................................................................................................................................... 74 VIII. DNTG Department: ............................................................................................................................... 75 IX.
Environmental Factors at Arvind Mills ........................................................................................ 79
Environmental Policy .................................................................................................................................. 79 Water Treatment At Arvind Mill: ............................................................................................................ 79 Effluents due to washing: ...................................................................................................................... 79 Effluents due to Mercerization ............................................................................................................ 80 Treatment:................................................................................................................................................... 80 Main treatment facility:.......................................................................................................................... 80 Pre-treatment facility : ........................................................................................................................... 80 Reverse Osmosis: ...................................................................................................................................... 81 Air pollution Control: ................................................................................................................................ 81 Solid Waste Management ........................................................................................................................... 81 X. XI.
Accreditations ............................................................................................................................................ 83 References ............................................................................................................................................... 85
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I.
PROJECT ABSTRACT
Project type
Textile internship
Industry
Arvind Mills Limited – Lifestyle Fabrics
Address
Denim Division Arvind Limited Naroda Road Ahmedabad – 380025 Gujarat India Tel: +91-79-30138000 Fax: +91-79-30138671
Mentor
Ms. Milli Das
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AIM: The project is based on a ten day internship , in Arvind Mills denim Department. It covers all the information and learning experiences related to manufacturing of textiles, denim in this case and all the processes involved namely:
Spinning Dyeing Weaving Finishing Testing Packaging
The main objectives of the project/internship were: 1. Understanding basic principles of production of textiles. 2. In depth study and understanding of all process involved in textile production and the machinery and equipment used. 3. Knowledge about the company 4. Understanding the company’s process flow in production 5. Study the work environment and practices followed for textile production. 6. Asses the faults and critical factors of production and determine the practices adopted by Arvind Mills.
COURSE OF ACTION: We devoted one day to visit each department related to the production of denim. In the departments, head of departments were assigned to us, for detailed explanation of the process involved. The head Of Department showed us the individual processes, explained the work flow and showed us associated machinery. We maintained a learning diary and took down noted on all information that we could acquire from the department. We then spent half an hour to one hour, depending upon the process, in each department, exploring the various machine features, writing down specifications and talking to the machine operators about the various problems faced during production. After the industrial visit, we would go home and take down additional information from the internet and any other available source, note in in our learning diary and compile this document side by side, so as to not miss out on any important details. Parts of this document have not been copied from anywhere, except for definitions, company or industry related information, diagrams and pictures.
Page |7 INDUSTRIAL PROJECT INDUCTION TIME TABLE DATE
TIME
DEPARTMENT
HEAD OF DEPARTMENT
21-05-2012
10:00 hrs to 15:00 hrs.
Spinning
Devesh Shah
22-05-2012
10:00 hrs to 15:00 hrs
Dyeing
Hitesh Shah
23-05-2012
10:00 hrs to 15:00 hrs
Weaving
Deepak Pandya
24-05-2012
10:00 hrs to 15:00 hrs
Finishing
KB Shah
25-05-2012
10:00 hrs to 15:00 hrs
Quality Assurance
Pranab Karmakar
28-05-2012
10:00 hrs to 15:00 hrs
Inspection And Packaging
RT Shah
29-05-2012
10:00 hrs to 15:00 hrs
Production Planning Ajay Dwivedi And Control
30-05-2012
10:00 hrs to 15:00 hrs
Marketing
Smita Deshpande
31-05-2012
10:00 hrs to 15:00 hrs
DNTG
Jignesh Shah
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INDIAN TEXTILE INDUSTRY: •
•
Indian textile industry and Market Size
Textiles sector contributes to 14 per cent of industrial production
4 per cent of National GDP
10.63 per cent of country's export earnings
Market Size
•
•
India's share of global textile exports is expected to increase from the current 4% to around 7% over the next three-years
Growth Rate
3-4 percent during the last six decade
9-10 percent during last five year
Scope of rivalry
Raymond India
Welspun India Ltd
Alok Industries
Gokaldas Exports
Arvee Industries
Bharat Vijay mills
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INTRODUCTION TO THE COMPANY ABOUT THE COMPANY: Arvind Limited started with a share capital of Rs 2,525,000 ($55,000) in the year 1931. With the aim of manufacturing the high-end superfine fabrics Arvind invested in very sophisticated technology. With 52,560 ring spindles, 2552 doubling spindles and 1122 looms it was one of the few companies in those days to start along with spinning and weaving facilities in addition to full-fledged facilities for dyeing, bleaching, finishing and mercerizing. The sales in the year 1934, three years after establishment were Rs 45.76 lakh and profits were Rs 2.82 lakh. In the mid 1980’s the textile industry faced another major crisis. With the power loom churning out vast quantities of inexpensive fabric, many large composite mills lost their markets, and were on the verge of closure. Yet that period saw Arvind at its highest level of profitability. At this point of time Arvind’s management coined a new word for it new strategy – Renovision. It simply meant a new way of looking at issues, of seeing more than the obvious and that became the corporate philosophy. The national focus paved way for international focus and Arvind’s markets shifted from domestic to global, a market that expected and accepted only quality goods. Cottons were the largest growing segments. But where conventional wisdom pointed to popular priced segments, Renovision pointed to high quality premium niches. Thus in 1987-88 Arvind entered the export market for two sections -Denim for leisure & fashion wear and high quality fabric for cotton shirting and trousers. By 1991 Arvind reached 1600 million meters of Denim per year and it was the third largest producer of Denim in the world. In 1997 Arvind set up a state-of-the-art shirting, gabardine and knits facility, the largest of its kind in India, at Santej. With Arvind’s concern for environment a most modern effluent treatment facility with zero effluent discharge capability was also established. Arvind has carved out an aggressive strategy to increase its current operations by setting up world-scale garmenting facilities and offering a one-stop shop service, by offering garment packages to its international and domestic customers. Of Lee, Wrangler, Arrow and Tommy Hilfiger and its own domestic brands of Flying Machine, Newport, Excalibur and Ruf & Tuf, is setting its vision of becoming the largest apparel brands company in India.
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BOARD OF DIRECTORS: CHAIRMAN Mr. Arvind N. Lalbhai He is a Science Graduate and has been associated with the Company for over 60 years. He has been the Director since March 1974 and Managing Director since January 1975 till November 2002. He is the former President of the Federation of Indian Chambers of Commerce and Industry. WHOLETIME DIRECTORS
Mr. Sanjay S. Lalbhai, Managing Director A Science Graduate with a Master’s degree in Business Management, has been associated with the Company for more than 25 years. Mr. Jayesh K. Shah, Director Finance A Chartered Accountant having distinguished academic and professional career, has been with the group since the last 17 years. OTHER DIRECTORS
Mr. Deepak M. Satwalekar A ‘B. Tech.’ from The Indian Institute of Technology (IIT), Mumbai and a post-graduate in Business Administration from The American University, Washington DC, he is the Managing Director of HDFC since 1993; He is also Managing Director and Chief Executive Officer of
P a g e | 11 HDFC Standard Life Insurance Corporation Ltd.; He has been a Consultant to the World Bank, Asian Development Bank, and other bilateral and multilateral agencies and has worked in several countries. He is a member of Governing Council of various management and educational institutions and government expert groups.
Ms. Rama Bijapurkar She is a Bsc (Hons) and MBA from IIM –A and has worked for McKinsey, Lintas and has been the Deputy Managing Director of MARG and a founder Director of MODE Services. She has also been consulting Hindustan Lever and other Indian and Multinational Corporates. She is visiting Professor at IIM- A. and is on the Board of Infosys Technologies Ltd., CRISIL, Titan Industries and Godrej Consumer Products Ltd. Mr. Jaithirth Rao With a Masters Degree from the University of Chicago and IIM-Ahmedabad, he is the Chairman and CEO of MphasiS BFL Ltd. and is on the Board of Cadbury India Ltd., Mahindra Holidays & Resorts India Ltd., IDFC Asset Management Company Limited and Gabriel India Limited Mr. S. Sridhar (Nominee of EXIM Bank) He is an Executive Director of Export-Import Bank of India Mr. Balaji Swaminathan (Nominee of ICICI Bank) A Sr. Gen. Manager and Chief Financial Officer of ICICI Bank Ltd, he is also Director on the Board of ICICI Infotech Ltd., ICICI One-Source Ltd., Kalyani Forge Ltd., Orient Paper & Industries Ltd. and Unison Hotels Ltd.
Mr. V.K.Pandit (Nominee of IDBI) He is a retired IAS Officer. Former Secretary to the Government of India. He is on the Board of Shree Maheshwar Hydel Power Corporation Ltd. , Induj Enertech Ltd. and Neyveli Lignite Corporation Ltd.
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COMPANY’S VISION (Information as collected from Company Website) WE BELIEVE In people and their unlimited potential; in content and in focus on problem solving; in teams for effective performance, in the power of the intellect. WE ENDEAVOUR To select, train and coach people to obtain higher responsibilities; to nurture talent, and to build leaders for the corporations of tomorrow; to reward, celebrate and activate all intellectual business contributions. WE DREAM Of excellence in all endeavors; of mutual benefit and prosperity; of making the world a better place to live in.
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ARVIND DENIM DIVISION: Arvind is a pioneer the manufacture of denim in India. Today with an installed capacity of over 110 million meters per annum, The Naroda plant accounts for 89% of the company's total denim fabric capacity of 108 million metres. CEO of Arvind denim devision is Mr. Aamir Akhtar There are many delightful features of Arvind denim: the position of 3rd largest producer of denim in the world; and an export network of 70 countries worldwide. Prominent products in this category include ring denim, indigo voiles, organic denim, bi-stretch denim and fair trade certified denim. This is apart from regular light, medium and heavy weight denims. They come in various shades of indigo, sulphur, yarn-dyeds, in 100% cotton and various blends. Arvind is a leading producer of denim worldwide. Design, Innovations and Sustainability have been their core competency and have played a key role in their success in producing the highest quality of denim and being the market leaders. They have a huge DNTG department that is Development and New technogy that is the hub of innovation for denims. The use of sophisticated ultramodern technology under the guidance of world-renowned designers has enabled Arvind to deliver many firsts in the international markets. The facilities of Arvind Denim are accredited with ISO 9001, ISO 14001, OEKOTEX 100, GOTS, Organic exchange standard, FLO for fair trade and Lycra Assured. As one of the largest denim producers in the world, Arvind caters to quality markets of Europe, US, West Asia, the Far East and the Asia Pacific. Labs are certified by NABL (ISO 17025 certification) The labs are accredited by Dupont, Levi Strauss. All the products are designed and modeled on the basis of expert design inputs coming from our designers based out of India, Japan, Italy and the United States. All Arvind Denim products come with the hallmark of distinctiveness and quality.
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MAJOR INTERNATIONAL BUYERS: (Information as given by HR manager) Major Buyers: Levi Strauss
Gap
H&M
Miss Sixty
Also: Mango
Abercrombie And Fitch
Jack and Jones
Pantagonia
Calvin Klien
Zara
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Esprit
Diesel
ARVIND’S BRANDS FOR DENIMS: Own Brands
Excalibur
Flying Machine
New Port
Ruff & Tuff
Licensed Brands
Gant, U.S.A. 1949
The Flying Machine brand is the oldest homegrown denim brand for Arvind. In 2007, it was revived and re-launched in a different avatar with a new logo, placement and philosophy. Since then it has witnessed tremendous growth. Now the company wants to take it to the top three level.
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SansaBelt
Izod
Pier Cardin Paris
Arrow
Cherokee
U.S. Polo
Arvind launched US Polo in 2008. It’s a premium knits-led brand having polo sports as its core theme. They have now decided to move US Polo jeanswear to a jeans floor in large format stores. This will enable them to be present on the same platform as other premium denim manufacturers
Energie
Energie was launched in India during A/W 2010. It’s a Rs 27 crores business for Arvind. The brand is for people who have been wearing jeans but need something more innovative, premiumThey offer our jeans at Rs 2,499 and go up to Rs 7,999.
Joint Venture Brands
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Tommy Hilfiger
Nautica
Lee
Wrangler
Wrangler Hero Riders
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II.
PPC DEPARTMENT
The production Planning and Control department is the pne that materializes the production flow and monitors it. The head of PPC department is Mr Ajay Dwivedi. The main objective of the production planning department is to execute mass production.
Sometimes the buyer selects the designs that he wants to get mass produced from the fabric database of over 8000 design collection developed by the research and Development department of Arvind Mills known as the DNTG department. The specifications and procedures for such designs are already listed in the database and now the work of the ppc is to efficiently carry out those procedures Other times the customer sends samples and requires the mass production for it. In such cases , the DNTG department develops the procedures involved for production of that sample by reverse engineering. Refer to DNTG department section of the document for more details. The PPC department then allots the machinery and time required for fulfillment of each procedure accordingly. The lead time is also decided by PPC on the based of order size, machine availability, profits involved and the urgency as per the consumer.
P a g e | 19 In case of orders of lower quantities, the PPC has to strategise the execution of the order and plan whether or not to accept it, since dyeing machines of slasher and rope dye have limitations as to the minimum amount of dyeing, for best results and avoidance of wastage The PPC department also plans separately for orders of export and domestic market as the demand vary from region to region. Arvind also has its own retail brands, like ruf and tuf jeans etc, but they are treated as buyers and not subsidiaries. The bottle neck opration that determines the lead time for the production is the weaving procedure. The loom capacity depends on the following factors:
Construction of fabric Loom Speed Efficiency
The production planning team need to coherently work on deciding whether the capacity of the plant is enough to fulfill the order in the given lead time. Usually the lead time for any particular order is 50 to 55 days, including all quality checks inspection etc. The thumb rule for calculation of lead time:
Pre- spinning procedures: 3 days Spinning: 15-20 days Warping and dyeing- 3 days For every weaving cycle- 3 to 4 days(weaving cycles depend on the order qty and above mentioned factors) Usually for one order about 8 to 10 weaving cycles required Finishing processes- 1 day for each process, if not covered in the integrated finish processing machine Inspection 2 to 3 days Washing 2 to 3 days
COSTING:
Spinning : Weaving : Dyeing : Finishing : Coating : Power :
Rs 1.10/kg/count (avg. weight 650gram/mtr) Rs 0.21 / pick Rs 4/mtr Rs 0.04/mtr Rs 4/mtr Rs 2.25/unit
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Labor wage : Rs 6000 to 8,500/month Inspection: Rs 0.65/mtr
RAW material :
Cotton 100 kilo cotton = 88 kilo of yarn(for combed yarn) (75% yarn realisation) Loss : 1 % sizing, 2.3 to 2.5 % weaving,1% warping (total 4 to 4.5%)
The production planning process for denims in Arvind is done on excel. Though an attempt was made previously to employ an ERP system, the project failed causing major loss of capital because an ERP system does not work for such a huge company with such diversification in the process. Process control is not possible as each order has a different requirement and hence a different set of processes to be executed. Moreover, the lead time and cost calculations, that are supposed to be taken care of by the ERP system, cannot take into account of all the possible factors at a plant as huge as Arvind denims The ppc head, Mr Dwivedi and his team are the ones, to plan each and every step of the production process, and it is their responsibility to deliver high quality products at the promised time.
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III.
PRODUCTION PROCESS: Spinning
Ball Warping
Beam warping
Rope dyeing
Slasher dyeing
Rebeaming
Sizing
Drawing in Looming Finishing
Inspection
Packaging
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1. SPINNING DEPARTMENT: Spinning is the process of conversion of fiber to yarn
Process flow of spinning department:
Drawing Carding
Spinning (open end rotar)
Winding
Blow room (opening, cleaning & blending) LAYOUT OF SPINNING DEPARTMENT: SLEEVE ROOM
BLENDOMET
COTTON GODOWN
FILTER ROOM
DRAWFRAMES
OFFICE
AUTOCORO DEPARTMENT
AUTOCORO STORAGE
CARDING DEPARTMENT
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The cotton fiber grows in the seedpod or boll, of the cotton plant. Each fiber is a single elongated cell that is flat, twisted, and ribbon like with a wide inner hollow (lumen).It is composed of about 90 percent cellulose and about 6 percent moisture; the remainder consists of natural impurities. The outer surface of the fiber is covered with a protective wax like coating which gives the fiber a somewhat adhesive quality. Bale of about 165-170 kg comes into spinning mill
Types of cotton Arvind Mills use: 1. Pakistan Cotton 2. J34 SG i. (It is a selection from non descriptive hirustum mixtures. Reselection from Bikaneri Narma. It is sown in the months of April/May and the crop is ready for picking by October/December.. J34RG and SG are grown in the states of Punjab, Haryana and Rajasthan and total production per annum is around 2.6 million bales of each of 170 Kg.) 3. Shankar-6 Gujarat cotton i. It is sown in the month of June-July and is ready for picking in November and may extend upto February. It is cultivated in an area of 4.4 million Acres in the state of Gujarat.
4. Organic cotton
P a g e | 24 a. (Organic cotton is being produced in-house by arvind mills, and also being procured from fully organic certified farms, as some environment conscious customers prefer to use it. b. Arvind’s organic cotton contract farming project is located in the cotton growing belt district of Maharashtra; Akola. )
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Blow room:
Process flow of blow room:
MPM
bale opener or cotton plucker
GBR cotton opener
axi flow cleaner
multiple mixer
ASTA particle cleaner
Rn cleaner
RSK cleaner
Dustek
a) BLENDING Machine used : Blendomat machine by Truetzschler
Model no. :
BDT 019/2300
Bale layout:
Both sides (2 rows)
Number of bales:
50-60
Weight of bales:
110-167 kg
Mode of bale laying:
Manual
Material in process:
Cotton with seeds and impurities
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Steps: Cotton is passed from bales and then to apron. Apron moves cotton to blending apron. Blending apron has sharp spikes the raise cotton until part of it is knocked off by the roll. Some of the cotton stays on apron. The cotton knocked back by roll and continues to blend until picked up again by apron. Another roll strips off cotton that was not knocked back by previous roll. Cotton falls on conveyor belt and is carried to next process that is blending through an overhead duct. Why it’s been done?It is necessary so as to obtain uniformity of fiber quality
b) OPENING
Machine used : GBR cotton opener- opens about 400 kg/hr
Steps: Lint cotton falls on apron and passes between feeder rolls to beater cylinder. The rapidly whirling beater blades take off small tufts of cotton, knock out trash, and loosen up the mass. The two screen rolls are made of screen material and air is sucked out of them by fan. This draws the cotton from beater and condenses it on the surface of the screen rolls from which it is taken and passed on by the small rolls. Air suction through cotton takes out dirt and trash. Conveyor belt passes cotton to another type of beater. From beater the cotton passes to a conveyor and is carried to picker. Why it’s been done?-
P a g e | 27 It is necessary in order to loosen hard lumps of fiber and disentangle them; cleaning is required to remove trash such as dirt, leaves, burrs, and any remaining seeds. GBR- Here the cottons are fed for homogenous mixtures and for removing dirts.MPM-8 – it has got 8 chambers. Generally used for homogenous mixture of fibers like while harvesting some cotton are from matured plants and some re not. So that it will affect the fabric. So, after homogenous mixing all will be the same.
c) Axi-flow cleanerThis is fitted with beaters .Cotton moves from GBR to axiflow by suction and impurities fall below in a bin under the gravitational pull. Objective of AFC is separation of heavy parts (impurities) from cotton.The opened up mass of fiber rotates around two cleaning rollers (beaters) with cylinder steel pins which beat the fiber material, allowing the coarse particles to be separated.The time (in hours) of the passage of material can be regulated The speed range of the beaters varies from 400-600 rpm Machine make:
Trutzschler (Germany)
Model:
052-2502
Pressure:
50-75 bar
Major parts:
Two metallic perforated cylinders and waste collector
d) MPM multiple mixerFitted with eight beaters. This sucks cotton from axiflowand pumps to asta meanwhile sorting the cotton fibers.Generally used for homogenous mixture of fibers Make: Trutzschler Model:
10236
Motor speed:
1750 rpm
Opening rolls speed:
800-850 m/min
Number of chambers:
10
Output:
30-36%
Pressure:
350 bar
Major parts:
This machine consists of material feed, reserve tank, reserve tank flaps, optical sensor delivery, rollers, and
P a g e | 28 material suction funnel.
e) ASTA: Objective of ASTA is Heavy trash separation from cotton. The air and material enters the separation tank in a stream via upper channel and hit baffle plates. Heavy particles are removed away from the lighter fibers by negative acceleration and the force of gravity. The lower channel generates an opulent air stream in the area of baffle plates, which guides the fibers to the outlet. Make:
Trutzschler (Germany)
Model:
ASTA 800
Principle:
principle of aerodynamics
f) DUSTEX: Dust removal is not an easy operation since the dust particles are completely enclosed in the flocks & hence are back during suction. The suction units remove dust 64% dust. Make:
Trutzschler (Germany)
Model:
CVT-4 1600
No. of machines:
2
Cleaning efficiency:
64%
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Carding:
Number of machines:
14
Make:
Trutzschler (Germany)
Model:
DK 803
Humidity:
56.5%
Temperature:
33.3 degree Celsius
Production:
80 kg/hr.
Card cleaning efficiency: 62-67% CV%:
1.2-1.7
Front Delivery speed:
210-240 meters per minute
Pressure:
325 pas
Carding is the process of removing impurities from fibers and producing a carded sliver of parallelized and straightened fibers
Before the raw stock can be made into yarn, the remaining impurities must be removed, the fibers must be disentangles, and they must be straightened.
The straightening process puts the fibers into somewhat parallel CARDING.
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The work is done by carding machine.
The lap is passed through a beater section and drawn on rapidly revolving cylinder covered with very fine hooks or wire brushes slowly moves concentrically above this cylinder
As the cylinder rotates, the cotton is pulled by the cylinder through the small gap under the brushes; the teasing action removes the remaining trashes, disentangles the fibers , and arranges them in a relatively parallel manner in form of a thin web.
This web is drawn through a funnel shaped device that molds it into a round rope like mass called card sliver.
Card sliver produces carded yarns or carded cottons that are serviceable to produce denim fabrics.
After carding, the carded slivers go to the draw frame At Arvind mills:
No of carding machines: 14 machines Brand name of machine: Trutzschler
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Drawing
Drawing is the process where the fibres are blended, straightened and the number of fibres in the sliver increased in order to achieve the desired linear density in the spinning process. The drawing process also improves the uniformity or evenness of the sliver. The number of drawing passages utilised depends on the spinning system used and the end products In arvind mills, the sliver is drawn through the draw frame twice. Draw frame used : Padamatex Total of 12 draw frames at the plant 1ST PASSAGE: parallel alignment of fibers, 6 slivers converted into one 2nd PASSAGE: output of the second passage of draw frame goes into open end/rotar spinning
Roving In preparation for ring spinning, the sliver needs to be condensed into a finer strand known as a roving before it can be spun into a yarn The roving frame draws out the sliver to a thickness of a few millimetres and inserts a small amount of twist to keep the fibres together. The drafted twisted strand is wound onto a bobbin which is then transported to the ring frame and used as the feed package for spinning yarn. Roving does not take place at Arvind Mills, as open end spinning is used, not ring spinning
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Spinning:
The plant at Naroda works entirely on open end spinning technology/rotar spinning and produces 5400 to 5500 tonnes of yarn a month with 5472 rotars being around on campus.
The speed of the rotar roll varies from 80,000 rpm to 130,000 rpm.
Machine installed :autocoro comb+spin technology
Corolab- automated yarn monitoring system(automatic detection of defects by drop wire technology)
The maximum count of yarn is 20
Open end spinning:
Rotor Spinning is a more recent method of yarn formation compared to Ring Spinning.
This is a form of open-end spinning where twist is introduced into the yarn without the need for package rotation. Allowing higher twisting speeds with a relatively low power cost.
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In rotor spinning a continuous supply of fibers is delivered from delivery rollers off a drafting system or from an opening unit. The fibres are sucked down a delivery tube and deposited in the groove of the rotor as a continuous ring of fibre. The fibre layer is stripped off the rotor groove and the resultant yarn wound onto a package. The twist in the yarn being determined by the ratio of the rotational speed of the rotor and the linear speed of the yarn. Sliver is fed into the machine and combed and individualized by the opening roller. The fibres 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 center of the rotor. The resultant yarn is cleared of any defects and wound onto packages. 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. Rotor spun yarns are more even, somewhat weaker and have a harsher feel than ring spun yarns. Rotor spun yarns are mainly produced in the medium count (30 Ne, 20 tex) to coarse count (10 Ne, 60 tex) range. The yarn is wound on a big package of about 4 kg. The use of this system has two basic advantages. It is fed by sliver, not as with the ring frame by roving, and so eliminates the speed frame from the process line. It can also be modified to remove any remaining trash, thereby improving the yarn quality.
Ring Spinning
Open-end Spinning
Bobbin rotates constantly for insertion of twist
Spool does not need to be rotated to insert twist
Cannot handle spools of bigger size
Much larger spools can be wound
Can spin finer yarns
3-5 times faster than ring spinning
Uniform and strong yarn
Uniform but flexible yarn with better dye ability
Combed yarns (finer)
Carded yarns (coarser)
P a g e | 34 Yarns for varied applications
Yarns for heavier fabrics such as denims, towels and poplins
Stronger
20% more twisted but 15-20% weaker as the yarn is coarser
Suitable for all staple fibres
Not suitable for man-made staple fibre spinning except rayon as the fibre finish clogs the rotor
P a g e | 35
2. WARPING DEPARTMENT Warping is transferring many yarns from creel of single-end package forming parallel sheet of yarn wound on to be a beam or section beam. Warping machines can process all type of materials including coarse and fine filament and staple yarns, monofilament, textured and smooth yarns, silk and other synthetic yarn such as glass. A warp beam that is installed on weaving machine is known as weaver beam. A weaver beam contain thousand of ends, but in denim production a beam obtain from warping is known as section beam because denim is made from dyed yarn that’s why first section beam can be obtained and then these section beam are combined on the stage dyeing and sizing to get required number of ends for weaving process. In denim production initially the yarns are first dyed and then weaving process is carried out . There are two method of yarn dyeing in denim production
Rope dyeing. Slasher dyeing.
Warping method used for both method of dyeing are different. The process used for rope dyeing is known as “BALL WARPING” and for slasher dyeing “BEAM WARPING” method is used.
BEAM WARPING
BALL WARPING
P a g e | 36
BALL WARPING SYSTEM:-
In this system of warping the yarns are wound on a large cylindrical roll in the form of twist less rope.
The balls are used for dyeing of denim fabrics.
In Arvind Mills, Ball warping involves creeling multiple ends of yarns (normally 350 to 500) and collecting them into a untwisted rope for dyeing.
This rope is wound onto a long cylinder called a log on a machine developed specifically for this purpose (the ball wrapper). Packager of warp yarn brought into the warping area one or two days prior to warping and allowed to condition to the ambient temperature and humidity of the area. They warp much easier if allowed to pre-condition in this manner. All of the packages are then loaded into a creel. The packages are placed onto adapters which are located on steel support pins throughout the creel. These adapters support the packages of yarn and insured that the package is remains aligned to the tensioning devices. The next step involves threading the tensioners.
After dyeing process the roll ends are separated and wound another warp beam usually the leasing comb and a collecting reed is used to achieve tangle free lease section. The warp beam, so produced is then combined on sizing for applying the size past and making the weaver beam.
P a g e | 37
MACHINE SPECIFICATION OF BENNINGER’S WARPING MACHINE Model
AGCH 9240.
Max. Creel Capacity
640. (V-Creel used).
Min. Crel Capacity
334.
Speed
20m/min to 1200m/min.
Tensioner Type
Electronic.
Pressure
200daN to 600daN.
I. Pressure set on the basis of fines and coarseness of the yarn count, i.e. more coarse more pressure is required to make the compact warping beam. II. In warping process humidity factor plays an important role because if humidity is less than 80% then yarn breakage is more. For obtaining the required humidity humidification duct are installed. III. To maintain the tension steel rods are used. Tension value is giving according to the yarn count. IV. Electronic sensors are used to sense the yarn breakages. WARPING MACHINE:Warping machine comprises on two parts,
s
1. 2.
Creel Section Head Stock Section
BEAM WARPING:-
P a g e | 38 In direct warping, yarn are withdrawn from the single end yarn packages on the creel and directly wound on a beam.
PASSAGE OF DIRECT WARPING M/C
Creel
Guide
Stop motion
Tensioner
Zig-Zag Guide
Drum
Direct warping is used in two ways a. ) Direct Warping can be used to directly produced the weavers beam in a single operation. This is especially suitable for strong yarn that do not require sizing. And when the number of warp end are relatively small. b.) Direct Warping is used to make smaller intermediate beam called warpers beam. The smaller beam are combined letter at the slashing stage (in the case of denim production they will combine at the stage of dyeing and sizing range) to produce weaver beam. This process is called beaming. For example if weaver beam contain 9000 ends then there would we say 9 warper beams of 1000 ends. If this weaver beam were to be made at one stage, the creel capacity must have 9000 yarn packages, which is hardly possible to manage and accommodate. In the production of denim option “b” is applied.
Warping Beam
P a g e | 39
Manufacturer Designation Working width Suitable for processing the following yarn Speed range Running speed Braking mechanism Tension range Measuring roller device Pressing roller force Pressure Comb Control Measuring instrument Beam drive Beam doffing Possible Beam Flange Diameter Size of Creel Special feature of creel Type of thread Tensioner Type of warp stop motion on creel Pitch Other standard equipment of warping Maximum weight of yarn on beam Production/shift
Sucker Muller Hakoba NZB D1000 Sensowarp 1600 A11 30 to 1000 mpm 475 mpm Electromagnetic brake 8 to 50 cn No 600 N/m 6.0 bar Zig zag (+ve) Electrical Beam pressure Indicator,tachometer,warp length presetter Spindle Driven Mechanical 1000 mm 700 Motorized creel cutting Pneumatic Electrical 270mm Length indicator Warp tension checking Movable wind screen 30-32 kgs 18-19 beams
P a g e | 40
3.
DYEING DEPARTMENT:
There are 2 types of dyeing techniques used at Arvind Mills:
Slasher dyeing Rope dyeing
slasher dyeing
rope dyeing
beam warping
ball warping
combination of warp beams to form sheat
dyeing
dyeing and sizing
rebeaming
sizing
CAPACITY: Total Capacity
110 million meters per annum
Slasher Capacity
70 million meters per annum
Rope Capacity
40 million meters per annum
Dyes used:
Indigo blue- china Sulphur dye- Black, Brown, Green
P a g e | 41
Dyeing Technique: 1. 2. 3. 4. 5.
Pure Indigo(light, Medium, Dark) Pure Sulphur(black) IBST- indigo bottom sulphur top SBIT- Sulphur bottom Indigo top Pigment dyes- rarely
The difference between slasher dyeing and rope dying is: Rope dyeing
Slasher dyeing
Warp yarn are in the form of a rope
Warp yarns are in the form of a beam
Can only handle dying capacity of more than 11000 m. Short slots not possible
Can handle dying capacity of more than 5000 m Short slots possible
Good depth of shade and lower washdown
Shade of depth not that good
No center to Selvedge shade variation
Center to selvedge shade variation may occur
Rebeaming is required after process hence more time consuming More expensive machine as it is huge
Rebeaming is not required.
It can only be done for coarse yarns, as the tension of the rope breaks the yarn Oxidation time is much greater
Can be done for fine yarns too
Less expensive machine
The immersion and oxidation times are lower
P a g e | 42
SLASHER DYEING (SUCKER MULLER) Total no of slasher machines at Arvind Mills: & slashers Ends combined: 575 ends, total of 25000 m Comines 12 warp beams into 1 In order to achieve fairly deep shades, the indigo is applied in a series of 6 dips(After each dip, darker shade is obtained, green oxidises to blue
Creel zone Pretwet zone Wasing zone(50 degrees. 22m/min) Indigo Dyeing Washing Pre- drying sizing Post drying Compensator
A slasher is a range is normally employed to apply size formulations onto warp yarns before weaving. This range when used for slasher dyeing of indigo, consists of section beams of warp yarn, which are forced into a sheet of yarn. 1 beam is 2500mts in length. 12 beams layers are put together in a sheet. Each beam has 575 ends.
P a g e | 43
This yarn sheet is then fed into a scouring and washing section where natural impurities are removed. Temperature of C is maintained and the sheet of yarns is under water for 4-5 seconds. The next section is where indigo is applied. In order to achieve fairly deep shades, the indigo is applied in a series of 6 dips(After each dip, darker shade is obtained) and sky applications to allow for shade build up. There is continuous color feed in the dye bath. The dye application is followed by afterwashing normal water at 0 C and drying. With some machinery arrangement, warp size for weaving is immediately applied. or sizing the temperature of 90 C is maintained in starch solution. After starching post drying is carried out(5-7 % moisture) and thereafter there comes the leasing zone, where there is separation of layers which were pressed together. Here the number of beams in the leasing zone is equal to the number of layer pressed together, i.e. 12 beams. The next section is the headstock, here rolls on beams are prepared for weaving.
Slasher Dye Range Slasher dyeing ranges have a number of advantages and unique characteristics. Slasher dyeing employs a sheet of yarn, which is wound directly onto a warp beam rather than ropes of yarn, which then requires additional handling. This type of dyeing works well with lightweight denims. In general, these machines require less floor space, enable smaller production runs, have a quicker turn over time, and are more flexible in their response to changes in the market. As an overall process these ranges have lower machinery cost; therefore, lower dye costs are realized for specific fabric types. The chemicals used in the dyeing and sizing range are as under:
(For dyeing)
P a g e | 44 Chemical Name
Description
Brand
Mercerol QWLF
Mercerizing agent
Clarient
Indigo
Dye stuff
china
Hyrdo
Reducer for indigo
BASF
Caustic soda 50% liquid
For general purpose
Local
Premasol NF
Anti Foaming Agent
BASF
Setamol BL
Dispersing Agent
BASF
Sodium Sulfide
Reducer for Sulfur Black
China
Sulfur Black BR-200%
Dye stuff
Arvind
Formic acid
for pH control
Local
Hydrogen peroxide
for oxidation
Local
(For sizing)
Chemical Name
Texo-Film Maiz Starch
Description
Sizing
Brand
Rafhan
P a g e | 45 Size-O-Bond
Sizing Softener
FFD
Wax
Sizing wax
Local
Size CB
Binder
BASF
P a g e | 46
ROPE DYEING Morrison Rope dyeing range is installed at Arvind, Naroda. In this method a warp beams first converts into rope beamers and then transfer to the 50 Rope Dyeing machine for the further process. Rope-dye ranges enable to produce pure indigo, sulfur bottom, sulfur top, and colored denim yarn. The yarn goes through scour/sulfur dye, wash boxes, indigo dye vats, over a skying device (to allow oxidation to occur), through additional wash boxes, over drying cans and then is coiled into tubs which are transferred to the Long Chain Beaming process. There are 14 tanks in this machine starting form Mercerization till Lubrication. The speed range of this machine is 030m/min with the production capacity of 2 sets in same time, hence the production per day become 36000x2=72000m at the speed of 25m/min. Normally the count range in Ne use in rope dyeing is (16s6/s) OE and Slub both. The detailed description regarding each box will be presented on 25m/min to set a standard calculation.
P a g e | 47
a) Creel Section:In this section 50 balls are setup at creels with generally 400 to 430 ends. Creels setup is as follows
a)The first section is known as setup section but after that it comes the machine layout portion i.e. there are 19 Boxes through which Rope passes for various parts as follows:-
Box No:-
Process Name
Activity
Temperature 70.C
1.
Scoring Process ( Washing)
If found Impurities of Yarns removed.
2,3,4.
Pre-Dye washing Process
Before Dyeing washing of Ropes.
50.C
5,6.
Shading Process
Shading taken care as per requirement.
N.A
7 to 14.
Dyeing Process
Indigo Tank do dyeing process for about 8 times i.e. Ropes enters N.A and exit 8 times from this tank.
P a g e | 48 15 to 18.
Post-Dyeing Process
19.
Softener Process
After Dyeing process this boxes gives a wash to Ropes to remove unnecessary dyes from surface of Ropes with the help of detergent. At this stage dryness of Ropes taken care with the help of softeners. Opening of Ropes is done after Process.
Effluent Treatment Plants*
N.A
* Effluent Treatment Plants is helpful in making a solid form of Indigo waste and make (pH) level neutralize
b) Dry cans and Coilers: In this drying process is carried out through Cylinders and Coilers are used to make Quality arrangements and to make 400 to 430 ends separate from individual Ropes.
c) Re-beaming department :Here they re-open the rope and winds it on beams so that they can be sized on next step. They have 6 Re-Beaming machines with the comb capacity of 410 ends. And there daily production is ~50,000m.
Re-beaming department The Impact of this Process is that Dyeing Process is done with the possible nearest accuracy and efficiency but it involves more cost than Sucker Muller in respect of Machinery, Workers Skills and Working Environment. It gives 5 times more Production than Sucker Muller. Here Quality is more focused in terms of Purity issues of Indigo. It gives
P a g e | 49 better penetration of Indigo on Ropes (Yarns) as Dyeing is done 8 times. It has a capacity of setting 40,000 meters at a time. Indigo extracts from plants that are naturals and there are synthetic dyes. We must know that Indigo is Insoluble element and to make it applied on the Ropes (Yarns) Caustic is added to the Indigo to make it soluble. Still this is not enough this just a formation of Soluble but to apply on surface of Ropes it requires a pathway, which is given by Hydro, and it makes the (pH) in its acidic media so that Indigo is directly applied to the Ropes (Yarns). The basic difference between Warp Dyeing and Rope Dyeing is that in Warp Dyeing- Dyeing and Sizing Process goes together whereas in Rope Dyeing the focus is mostly on Dyeing Process and then after the Ropes is filled into cans and then Ropes are opened as a Warp and thereafter Sizing part is done.
The lists of chemical use in dyeing are: Chemical Name
Description
Company
Mercerol QWLF
Mercerizing Agent
Clarient
ALkapol ASD
Wetting Agent
Alka
TradersCausic soda 50% Liquid
Caustic soda
Premasol NF
Anti Foaming Agent BASF
Setamol BL
Dispersing Agent
Indigo China
Dye Stuff
Sodium Hydro Sulfide
Reducer for indigo
BASF
Sulfur Black BR-200%
Dye Stuff
China
Sodium Sulfide
Reducer for S.Black
China
Formic Acid
for pH control
Tufail
Hydrogen peroxide
for Oxidation
Local
Immacol-C
Lubrication
Clarient
BASF
BASF
P a g e | 50 Alkasoft 5200 Paste
Softener Traders
Alka
Urea
Moisture regains
Local
P a g e | 51
4.
SIZING DEPARTMENT
There are complete automatic computerized sizing machines (Benninger). Here they can load 2 sets at a time. In this machine, 2 sizing boxes having capacity of 400x2 lit in which warp sheet passes through in such a way that 6beams(half sheet) pass through 1st size box and other half sheet pass through 2nd size box and then they combine together for weave able beams. The avg. maximum workable speed is 4560m/min. the avg. production of this dept. per day is ~50,000m. Following chemicals we are currently using in Sizing are:
Chemical Name
Description
Company
Texo-Film Maiz Starch
Starch
Rafhan
Arca Base
Acrylic Binder
Size-O-Bond
Sizing Softener
FFD Brothers FFD Brothers
Checking and monitoring the sizing process Programming the machine:The easy to follow visualization and recipe management, in which all the machine and textile parameters are stored, permit fast and simple programming.
P a g e | 52 Sizing monitoring:The sizing process is automatically monitored. All setpoints are specified with upper and lower tolerance limits. Deviations from the programmed value are displayed at once and instructions for their rectification are explained in the language of the operator.
Controlled tensions:The special arrangement of rollers in the 3- roller set prevents threads from slipping through and keeps the thread tension constant in the dry split section when changing beams.
Reproducible size cooking:-
The SIZEMIX cooker, equipped with a high powered agitator ensures homogeneous liquor. The cooker is programmed via the size recipe at the machine PC. In this way, cooking temperature, water quantity and cooking time are preset and automatically maintained. Attendance takes place optionally from the PC or directly at the cooker.
Proposed numbers of ends/inch in size box:The table describes the numbers of ends/inch of ring spun an open end yarn in size box according to count.
P a g e | 53 Maximum ends/inch in Size box Yarn count Ring Spun Open End 10 35 31 20 50 45 25 56 50 30 62 56 35 66 60 40 71 64 50 80 72 Viscosity of size paste:Viscosity of size pate should not deviate from required value. Less viscose paste makes adhesion of size material well but coating on the surface of the yarn is not done properly. While paste with higher viscosity coats the yarn very well but adhesion of paste into the core of yarn in terms of increasing its strength is not done properly. Size box temperature control:The degree of size penetration and coating depends not only on the nature of yarn & the size solution but also upon the viscosity which in turn largely depends on the temperature. It should be about 200F°-206F°. Fluctuation should be ±3 F°. The temperature gauge should be installed on the size box. Perforated copper pipe lining is laid in the bottom of size box to supply the steam for keeping the paste warm up to the above mentioned temperature. Low temperature will make gelling of paste which will not penetrate through the yarn and higher temperature create thinning of the size paste which is also unsuitable to be used as sticky paste. So to maintain the temperature of above value is very important. If the size paste is prepared with rich PVA or CMC then temperature of 75C° to 80C° is sufficient. Moisture content in the yarn:The moisture content in the sized yarn should not go below 6%. Otherwise the coating of size film will not allow absorbing moisture in the loom shed which is necessary for good working. For this moisture monitor is being supplied with the machine. The temperature of the drying cylinders should be kept 140-150 to maintain 6-7% moisture in the yarn.
5.
WEAVING
Weaving is the interlacing of warp filling yarns perpendicular to each other at 90 degree. These are practically an endless number of ways of interlacing warp and filling yarn.
P a g e | 54
WEAVING MACHINES (LOOM)
The waving machines are named after their filling insertion system. Schematics of the filling insertion systems that are used in the market are: I. Shuttle II. Projectile III. Rigid rapier IV. Flexible rapier V. Air jet VI. Water jet Based on the filling insertion system, the weaving machine can be classified as shuttle and shuttle less weaving machines. Shuttle looms have been used for centuries to make woven fabrics. Air Jet Looms Or Air Jet Weft Insertion System
P a g e | 55
This system is most improved form of weft insertion. In this system, the mechanism and machine parts have been totally eliminated used to drive the weft insertion source. This facilitate to increase the insertion rate up to 2500 p.p.m this type of machine is firstly commercialized by Swedish engineer Max Paabo in 1951. weft thread is propelled using compressed air. It is simple operation with reduced mechanical parts and hence the maintanence cost is very low.
The working principles of air jet weaving machines are based on carrying the yarn by the friction of the air jet. During the yarn’s forward movement by the air in the sheds, the velocity of the weft yarn decreases because of the decreasing pressure and the disturbance on the air flow direction [. The air jet must provide a constant speed to the weft yarn along the weaving wideness. However, weft yarn of a certain mass is carried by a single jet at a limited distance. That is why the relay nozzles are installed at certain distances, in order to prevent a decrease in yarn velocity. The relay nozzle system and the general characteristics of the weft yarn speed in the shed. These are implemented on a movable hollow-needle or slay system. The basic function of the main jet is to load the weft yarn into the shed, and then to carry it to the first relay nozzle at a certain speed. The weft yarn suddenly reaches high velocity by means of the main jet. To preserve weaving defects and asynchronous beat-up movement, the weft yarn position and the instant velocity of the weft yarn must be fully controlled during the weaving process.
P a g e | 56
Advantages of Air-Jet Weaving Machine
High productivity High filling insertion system Reduced hazard because of few moving parts Low noise and vibration Low spare parts requirements To increase the production of loom by increasing the speed and by increasing the width of loom Machines are versatile and roust to produces light to heavy value added fabric Almost all loom motions are being controlled electronically These looms can be operated up to 40 looms per operated Fully auto matic lubrication system Produce 100% export quality goods
LOOM MOTIONS
There are three types of loom motions which are given below;
IV. a. b. c. d.
Primary Loom Motions Shedding picking beating take-up motion
P a g e | 57 e. let-off motion V.
Secondary Motion Warp stop motion Weft stop motion Warp protector motion Weft replenishing motion
VI.
Auxiliary Motion Terry motion Selvedge motion Weft petering motion Temples Brake
Weaving Department (Arvind Mill) After passing through different processes such as Spinning, Warping, Dyeing and Sizing this is a stage where Raw Fabric is processed and then finally it goes to Finishing Department. Now this stage is processed through Zax a loom set which is basically a model of Machines. These Machines works with a speed of 700 to 750 Rotations per Minute (RPM). There are 203 Machines out of which 159 are Zax Machines and 44 (209i) Machines. There are 13 meters per Roll as per customer’s requirements and after
P a g e | 58 making a Raw Fabric, it generally goes for detecting the defects. Generally, yarn is produced from cotton, filaments, lycra, Polylycra.
Warp Beamers first installed to the Air jet loom set, which is Technology from Japan (Tsudakoma) and then after a weft is entered into nozzles through air pressure. Warp is seen vertically on these machines and weft is horizontal to it. Weft enters through censors and passes the full lobby of warp and the dents of warp are set before starting the machine. Dents are defined as gap between two ends. The larger the dents the lesser will be the gap between two ends. Generally, one machine produces 500 meters of Raw Fabric daily depends on picks. In addition, to produce in such a hassle environment you need to have 75 to 80 % of humidity required in every textile mills and due to this 10% contraction of fabric takes place in weaving department. There is inflow of cool atmospheric air from above floor and outflow of air ventilation is given at underground level. There is air blower attached on the above of such machines to remove unwanted fibers on machines, which is continuously rotating for cleaning purpose.
After one beam is over there is a need for knotting to have a continuous production for Raw Fabric and for that, this department is having a Knotting machine to join the next beam. There are indicators on each machine for the Terminologies such as T- Total Breakages W- Warp Damages F- Weft Breakages L- Leno and other Breakages.
This indicators help operators in make out damages that occurs due to Dyeing and Sizing and sometimes due to weft also. Weft is procured from outside suppliers, so if there are more damages or breakages of weft then suppliers are to be aware and they will have to give more focus on these breakages.
Due to hassle, working environment workers are given Earplugs and Masks due to humidity level. There are 100 workers in a shift and total there are 3 shifts and
P a g e | 59 approximately 300 workers work in this department. Recycles wastewater and converts denim waste to denim paper, in keeping with their eco friendly production process. MAJOR DEFECTS :
Band pick Double end Starting mark Weft cut
The defect acceptance percentage at Arvind is 2.4 and efficiency is 85-87%, efficiency being measured in terms of number of picks to be inserted vis-à-vis actual number of picks inserted.
6.
PROCESSING /FINISHING
Finishing of grey denim fabric normally carried out after weaving. It takes an important role infabric properties, appearance, softness and residual fabric shrinkage. The department churns out 300000 meters of finished denim cloth a day. The main purposes of applying various finishes may be summarised as under. 1. HIGH SALES APPEAL: To impart properties of attractive appearance, supple handle, softness and good drape. 2.
HIGH WEAR QUALITY: This refers to adequate tensile and abrasion strengths, dimensional stability, crease recovery and freedom from pilling.
3.
BODY PROTECTION AND COMFORT: This relates to proper heat insulation, moisture absorption and air permeability.
4.
SPECIAL EFFECTS: These include water-repellency, reduced flammability, mildew and moth-proofing, anti-static behaviour and soil release property.
Classification of Finishes:-
P a g e | 60 Considering the existence of a large number and a great variety of the finishes for the cellulosic fibres, it is understandable that a completely satisfactory classification is not possible to make. The finishes are often sub-divided as physical and chemical, permanent and temporary, deposition and reactive etc. Sometimes the finishes are classified according to the effects obtained like appearance, wearing qualities, weighting etc. To complicate the matter further, the final folding and packing of the materials is sometimes included in the list. However the following description, though not perfect, is fairly rational and does justice to the topic. Physical /Mechanical Finishes:(a) TEMPORARY / NON PERMANENT (i) Calendering: Swizzing, Friction, Chasing, Schreiner, Embossing and Felt (ii) Beetling (b) DURABLE (i) Raising, Sueding, (Emerising or Peach Finish) (ii) Shrinkage Control Finishes Chemical Finishes:(a) TEMPORARY / NON PERMANENT (i) For Handle and Appearance: Softening, Stiffening, Weighting, Lustering (other than Mercerising) (ii) Special Effects: Water-Repellency, Flame-Retardancy, Mildew Proofing (b) PERMANENT (i) Crease Recovery, Softening (ii) Water-Repellency, Flame-Retardancy, Mildew-Proofing
Integrated Finishing Range for Denim Arvind Mill, Naroda boasts of 2 integrated finishing ranges. In integrated denim finishing range, the singeing and shrinking is carried out in a single range. This reduces the process time, material handling, cost of production and labour cost.
P a g e | 61
Process sequence The processes of a typical Integrated denim finishing range includes the following stages: Brushing: In the integrated finishing range, the grey denim fabric is first passed through a brushing and suction unit, where loose lint, fluff are removed from the fabric surface. The protruding fibers adhere on the fabric surface are also raised to burned in the next process Singeing: The denim fabric is then passes through a singing unit. Here the fabric is singed two times on the face side. lame temperature is 800 to 990 C.
P a g e | 62
Menzel Denim Singeing Machine
Technical Data
Machine speed : 10 to 100 Mts/ Min. Fabric width : 600 to 3200 mm. Drive : Ac invertor.
Chemical Padding: The denim fabric is then padded to apply finish to the fabric. Here the fabric passes into a full immersion pad and finish is added at high wet pick up. The finish is necessary to properly lubricate fabric for the subsequent skewing operation. Desizing (Dhall): Continuous desizing ranges are suitable for eliminating the size material from denim fabric with the help of rapid enzymes in the impregnator tank. It is then developed in the steamer for suitable time. It is then subjected to intensive washing, and followed by cylinder drier. The inlet is into -scray . The staem temperature is 100 2 C, pressure of 1. 0. bar, while the wash oxes have normal water with temperature of 3 C. Skewing: After chemical padding, the fabric is stretched by passing through two pulling devices and then passes through a skewing unit, where it is skewed. Now, skewing being an important issue shall be dealt with more details. Skewness in twill Fabric : The skewness in denim fabric, particularly in twill weave creates a serious problem in subsequent garment manufacturing and its washing. Leg twist is a major problem in denim manufacturing. Due to this problem the leg is rotated in the opposite direction of the twill of the fabric after laundering. Leg twist is assumed to be happen due to the directional yarn stresses. These are inherent in regular twill weave fabrics and developed during weaving. During washing
P a g e | 63 the yarn stresses is relaxed which change the regular position of interlacement between warp and filling yarns. Due to this reason the legs are twisted. Normally leg twist not shown on garment stage. It only observed after laundering of the garment. Although leg twist appears after first laundering and it increases progressively with repeated launderings. Ideally warp and weft should be at right angle to each other in normal fabric. Skew in the fabric occurs when the warp are displaced from their vertical position or when the weft are displaced from their horizontal position.
Woven fabric skewness
The degree of skew movement depends upon yarn characteristics, weaving tensions, and the fabric structures.
Pre-drying: The fabric is then passes through drying cylinders for partial drying of the fabric. Here 75-85% moisture are removed. The steam cylinders drive moisture in to the core of the yarns and reducing itto the 15-17% which is required for optimal sanforizing Compressive Shrinking: Subsequently, the denim fabric passes through a compressive shrinking unit where the denim fabric is pre-shrunk according to the grey potential shrinkage of the fabric, so that the residual shrinkage should be under tolerance limit. 100% cotton denim may require about 14% moisture for effective pre shrinkage. Moisture should be uniform thorough outthe length, width, and depth of fabric for effective shrinking. The compressive shrinkage unit consists of a heated and polished stainless steel cylinder, Tension Roller, Pressure Roller and guide rollers. Both the tension roller and the pressure can be adjusted as per requirement. A rubber belt cooling device is fitted with a water spraying arrangement on both faces of the rubber belt. Rubber belt unit is equipped with belt grinding roller and a suction device for dust removal from the belt grinding device. Palmer Cylinder: After the compressive shrinkage unit, the fabric is passes through a palmer unit, where the fabric is dried and iron. The functions of the palmer cylinder is: • To dry the denim fabric to a level of about 4% relative humidity and set shrinkage, • Adjust the shrinkage, • To compare incoming and outgoing fabric tension and determine fabric shrinkage,
P a g e | 64 • It helps in precise adjustment of fabric shrinkage. It pulls the fabric and precisely control tension on the fabric. • It gives a pressing and calendaring effect on the preshrunk fabric Cooling Unit At the exit of the palmer there is a cooling can. The unit consists of one, two or three stainless steel jacketed cylinders equipped with chilled water circulation to cool the hot fabric as it comes out of the Palmer unit. Delivery unit The delivery unit consists of big batching arrangement and a plaiting device. A stainless steel scray can be equipped for continuous operation.
P a g e | 65
VII.
QUALITY ASSURANCE
Arvind is committed at providing the best quality of fabric to the consumers for over 80 years now. The quality control is an integrated process that starts when the customer gives the order, and the DNTG develops the samples accordingly, it is checked for quality assurance measures and compliances with customer needs. At later stages the fabric is inspected and testing of parameters of fabric is done. Essentially there are 2 major parts of quality assurance
quality Assurance Testing
Inspection
Physical Testing
in process
Chemical Testing
final
Shade testing Process Control shipment clearance certification and accreditation
P a g e | 66
INSPECTION: Arvind follows 100 percent inspection procedures. The acceptance level of the fabric depends on the customer preferences. Inspection department uses 13 Kitamura Machine to find such defects in fabrics. The inspection frame is aligned at an angle between 45 and 60 degrees. Speed of fabric on inspection m/c : 25m/min Light of 100 Lux Inclination Cost of inspection rs0.65/mtr There are two inspectors to keep continuous watch on fabric for finding the defects. The 4point grading system indicates that as per customer requirement defects are allowable upto their levels. We have observed that in VF brand the 4-point allowable are only 4 that is total 16 defects per 135-meter roll.
4-point grading system is used for inspection of fabrics and this includes: Size of defect
Penalty Points
3” or less
1 Point
3” to ”
2 Points
” to 9”
3 Points
More than 9”
4 Points
Holes or Openings(Largest Dimension) 1” or less
2 Points
More than 1”
4 Points
No penalty points are recorded for minor defects. Major Defects are classified as follows:Major woven fabric defects such as slubs, holes, missing yarn, conspicuous yarn variation,end out, soiled yarn, and wrong yarn.- Major knitted fabric defects are mixed
P a g e | 67 yarn, yarn variation, runner, needle line, barre, slub,hole, press off.- Major dye or printing defects are print out, dye spots, machine stop, color smear or shading.
•Points per 100 square yards = Total points scored in the roll x 3600 Fabric width in inches
x Total yards inspected
•Fabric containing more than 40 points per 100 square yards is considered as SECONDS At the beginning of the month the inspection department gets the production plan for the entire month and they plan their procedures accordingly. The finishing department gives the material transfer note to the inspection department where the material is checked for the following defects:
Spinning related Defects:
Warp Slub
Weft Slub
Thick end
Coarse/fine weft
Weft bar
Weaving preparatory related defects
Knot
Slack end
Ball formation
Size patches
Weaving related defects
Starting mark
Tight end
Weft float
Knot
Moiré
Repaired warp
Double end
P a g e | 68 Bowing and Skewing Check for skewed, bowed and biased fabric. For this purpose check the bowing and s skewingat every 10 meters. The bowing and skewing are calculated as follows: Bow: A bow is an uneven deviation of a weft from a line drawn perpendicular to the selvedge of the fabric. A bow may have different forms: Single Bow%= Dip of the Bow (Maximum deviation from perpendicular line) X 100½ Width of the fabricDouble Bow%= Dip of the Bow (Maximum deviation from perpendicular line) X 100 ¼ Width of the fabricSkew: Skew is a straight line deviation of a weft from a line drawn perpendicular to the selvedgeof the fabric. Skew%= Dip of the Skew (Maximum deviation from perpendicular line) X 100 Width of the fabric If the average Bowing or Skewing for a roll is more than 2-3%, reject the roll.
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TESTING Phisical Testing: The samples are tested for/by: 1. Yarn evenness: USTER TESTER 5 2. Statex CSP(cascade strength tester) system: yarn count and strength 3. Single yarn tester 4. Instron 4465: Tensile Test for fabric 5. Elemendorf Tearing Strength: tearing strength check by application of 9000g force 6. Chatillon Stiffness Tester- resistance to bending 7. Paramount humidity checker- for humidity control 8. Stretch/elongation test- weight of 1.35 kg applied on a designated swatch sample for half an hr 9. Dimensional Stability and skew movement test 10. Shrinkage test- measure shrinkage after washing thrice + conditioning 11. Ozone test chamber by USA inc. 12. Snarl indicator 13. Twist tester- Statex (14.4 tpi)
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Shade testing: The software used for shade testing is EASY MATCH.
HunterLab's EasyMatch QC software gives unprecedented flexibility to process, display, analyze and report color measurement results. Color measurement and analysis software reports absolute and color difference data in all widely used color scales, for various lighting and observing conditions. Pass/Fail functions provide fast go/no-go decisions. Data can be reported numerically in tabular or spreadsheet form. Data can also be graphically displayed as color difference plots, trend plots and spectral curves. All results can be viewed, stored, printed or imported into your database programs.
The software uses a spectrophotometer to record observations, and plots deviations from avg and perfect sample for each roll. It also provides pass and fail options for rolls that deviate too much from noraml value making it very easy for the operator to assure quality and minimise shade variation. It also helps in shade wise differentiation and categorisation of rolls. So that the consumer may be able to easily distinguish between lots of various shades
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Chemical testing Tests requested by preferred customers:
LEVI’s Test method Ph
ISO-3071
Crocking
AATCC-8
SPOT TEST
SI 1005
WATER repellancy
ISO 105-E01
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ISO 105-E02
Alkali
ISO 105-E04
VF corporation Test
method
Ph
AATCC-81
Crocking
AATCC-8
WASHING
AATCC-81
POLO method Ph
ISO-3071
Crocking
ISO 105*12
SPOT TEST
SI 1005
WATER repellancy
ISO 105-E01
Acid
ISO 105-E02
Alkali
ISO 105-E04
Washing
C06-AIM
Chemical Tests Conducted in the lab: 1. Raw Material checking like dyeing/finishing auxhillaries a) Basic chemical. b) Percentage of purity of Hydros, Caustic acid, peroxides etc c) Purity performance of dyes like indigo, vat sulphur d) Auhilaries like wetting agents, sizing, finishing etc 2. Stock Weight of indigo (gpl)- Brandsbender moisture tester (105 degree c. for 4 hrs) 3. Weighing balance – Mettler Toledo 4. Crockmeter – AATCC 5. Formldehyde content in dye/stock bath 6. Thermo orion pH meter
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7. Launder-O-meter 8. ATLAS crockmeter 9. Genesys 10 spectrophotometer 10. Muffle furnace 11. Cintex incubator 12. EEC beaker dyeing machine 13. USA ozone test chamber 14. Flamability tester- coming next yr
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PACKAGING DEPARTMENT: Details on the packages : 1. 2. 3. 4. 5. 6. 7. 8.
Shipment no. Date Sort no F.M.C Code no Meters Flags/points Opt no.
Rolls of approx. 135m each sealed by polythene Spec. of polythene cover: Plastic bags of 23 micron used
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VIII.
DNTG DEPARTMENT:
The Development and New Technology Group department is a critical unit for the innovation and creativity that Arvind mills projects. The department has been constituted in such a manner that it has 2 parts
The Design Team The Technical Team
Design Team:
The design team has a constant responsibility of re-innovating denims. It consists of fashion consultants from Europe and other countries along with the textile experts and textile designers. The team works together to create a completely different denim design. Though it seems like innovation in design in denims has limited scope, this group of professionals use their creativity and constant thinking skills to come up with unprecedented designs. These new designs are featured in fashion shows across the globe, for top fashion experts to see and review, and hence maintain the exclusiveness of denim produced by Arvind Mills. Top designers like Calvin Klien, Chanel etc. and brands like Zara, Abercrombie and Fitch, Mango, Gap and many others, select these designs and order them to be produced in mass. The designs can be created by changing one of the following characteristics of the fabric :
1. Weave of the fabric:
P a g e | 76 (denim is usually 3 x 1 twill)- variations are made in twill weave or by changing the nature of the weave all together. Like 2X1 or other variations 2. The dying procedure’s output: (usually done with indigo and sulphur dyes) – the dying can give colour effects to the fabric. Different compositions of dyes are used and innovations and creativity in the use of colors, produces more number of designs. Sometimes the weft and the warp are of different dyes, creating an iridescent effect. Though traditionally blue or black, many other colours of denims are created 3. Fiber Used: Authentic denim uses cotton fiber, but for design variations cotton blends are used. Light weight yarns like polyester are used to manufacture denim used in garments like jeggings and lighter weight denim requirements. Most popular addition to denim fabric is Lycra for streatchability as that is a prominent feature of jeans. Also the yarn count and yarn density dictate the nature of fabric formed. Though yarn of higher count is used, as denim is thick fabric. 4. Finishes Applied: Fabrics can be re-innovated in terms of the type of finish applied, Now-adays, there are a variety of finishes that can be applied to any fabric and same goes for denim. Usually mercerization is a process not done for denims, as it does not require very soft and smooth fibers, but inclusion of finished like mercerization or resin finish, can completely change the look and feel of the fabric. Other aesthetic finishes, like partial napping or emerization, anticrease finish, permanent creases by resin finish can be given.
The following are a few lines of denim that have been developed and new products are added to it every day: 1. Kato (Japanese denim line):
P a g e | 77 Kato brings in the authentic attributes of denim in collections, fabrics mostly made on the shuttle loom and with selvedge. For s/s 2011, we have work wear cast in nappy selvedge denim, indigo with indigo-dyed Fill-and-Glen checks denim to name a few. His collection serves as early directions for all brands.
2. ADL (American Denim Lab): The ADL line is specifically for the US brands. The s/s 2011collection has special attractions in the form of colour denims, indigos with colour fills andsummer lights in excel along with the authentic core line 3. Euroline (European denim line): The Euroline is specifically for the brand needs inEurope. The s/s 2011 collection has an introduction of four new indigo shades omega, greycast indigo, oil authentic blue cast indigo, tribe–green cast indigo and clan–petrol blueindigo, all in fine subtle slubs in compact construction. 4. Metro (Indian denim line): The metro line is designed by Arvind’s in-house design teamspecifically for Indian brands. The collection has the flavour of a true Indian denim. For thecoming season, we have a set of fine coated products and a big set of power stretches for jeggings in indigo and black. We have also recently launched a collection in Excel calledExcelush in collaboration with Birla Cellulose.Excelush is a super soft, lustrous and bouncy denim fabric. It is made from a highly refinedeco-friendly and sophisticated process after scientific research and development conductedat Birla Research Institute. 5. New washes, treatments: We wash our collections in laundries around the world,including LA, Italy, Turkey, Korea, Japan and in our own lab in Ahmedabad. Some of thenew washes we are doing presently have crispy raw touch, naturally worn/used look, goodlocalised abrasion, extreme contrast of high and low where some areas still show the depthof colour even after heavy washing, a comeback of acid wash look, fully wash out look withdirty areas. 6. New colours:
P a g e | 78 In the indigo family, one can expect green cast indigo, grey cast indigo,greasy oil cast indigo, petrol blue cast indigo, hydron blue, and baby blue. In the purecolour family, one can expect all black, stay black, fade black, gunmetal grey, smoky grey,burgundy, diner green, and coral blue.
Technical Team:
The technical team of the development and new technology team aims at developing the fabric as per customer requirements. They have technicians and fabric experts who constantly work together and collaborate with each of the processing units to get the desired output of the fabric. Then, they calculate/concur and document the exact procedures and processes to be followed to create the fabric exactly matching customer requirements. Once the processes have been determined by the DNTG department, they are delegated to the individual units for mass production. The DNTG DEPARTMENT at Arvind mills has a databse of more than 8000 fabrics, that have been created for all kinds of uses. The designs range from all kinds of usage of yarn, to differentiation based on any of the factors mentioned above. Customers and designers may choose out of this data base to order in bulk, The data then goes to PPC department, that is production Planning and Control and the mass production of fabrics start.
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IX.
ENVIRONMENTAL FACTORS AT ARVIND MILLS
ENVIRONMENTAL POLICY Arvind Mills commits itself to continually improve our environmental management. It strives to go beyond the requirements of the applicable environmental laws & other regulations through:
Optimizing usage of cotton, energy, chemicals & water. Adopting preventive strategies to reduce the generation of effluents, waste & air emissions. Maximizing the recycling of inevitable wastes. Encouraging suppliers & buyers to become environmentally responsible. Maintaining a safe working environment. Increasing the green cover. Training employees on environmental issues.
WATER TREATMENT AT ARVIND MILL: Arvind Limited at the main site at Naroda also possess chemical, biologicaltreatment facilities to treat 10000 m3/day of effluents to meet the pollution control board norms.
Effluents due to washing: The effluents are generated from the washing carried out in between successive processes.
In the dye house, after dyeing activity, fixation of dye is one of the most important stages. Usually, 70-80% of fixation is practicable and the rest i.e. 20% of the dye used comes out in the effluent generated due to washing. Effluent generated from the dye house has high concentration of pollutant as compared to other processes in the textile processing unit. It also contains high amount of inorganic salts like sodium sulphate or sodium chloride which is used for dye fixing and acts as an electrolyte.
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Effluents due to Mercerization
Mercerization imparts shining characteristic to the fabric. Washing after mercerization generates typical effluent containing caustic solution and other impurities. Bleaching is done by peroxide method.
Treatment: The treatment processes at the water treatment plant at Arvind is divided into three parts: i) ii) iii)
Main treatment facility, Pre-treatment (prior to reverse osmosis) Reverse osmosis.
Main treatment facility: Effluent in the form of generated from the sizing & de-sizing, bleaching & sections are subjected to processes, both physical and chemical
Effluent is collected in an equalization tank. After pH adjustment there is addition of poly electrolytes Then the effluent is sent to the clarifier for sedimentation.
Effluent from the dying unit is collected separately in an equalization tank where:
pH is adjusted and a chemical is added in acidic medium (pH 5.5) to decolorize the effluent. The unit uses a chemical Micro Plus which is claimed to act as a color removal agent. This effluent is then mixed with the entire effluent from the mercerized, sizing & humidification sections. These effluents are then fed into biological system comprising of degradation of organic components by microorganisms Then it is sent to sedimentation in clarifier and to the aeration unit. In the aeration unit it is kept for a time of approximately 16 hours DO level is maintained at 2.5 to 3.0.
Pre-treatment facility :
P a g e | 81 Pretreatment or primary treatment facilities are adopted before the effluent is subjected to reverse osmosis. This stage comprises of two unit operations in succession turbocirculator followed by pressure sand filter. Turbo circulator is basically a flash mixer. After main treatment facility, poly aluminum chloride, poly electrolyte are added in the effluent and are passed to turbo-circulator and then to the sand filter before being subjected to reverse osmosis. The unit has intermediate storage tank of capacity 2400 cubic meter for storage of the treated effluent.
Reverse Osmosis: After pre-treatment the effluent is sent to the reverse osmosis plant. Reverse osmosis is just the reverse process of osmosis. Osmosis as we know, is a natural process and is the tendency of two liquids of different concentrations separated by a semi permeable membrane, to move from low to high concentrations for chemical potential equilibrium. But in reverse osmosis, when high pressure is applied, liquid moves from high concentration to lower concentration. Reverse (RO) is a method that removes many types of large and from solutions by applying pressure to the solution when it is on one side of a selective . The result is that the is retained on the pressurized side of the membrane and the pure is allowed to pass to the other side. Reject of the reverse osmosis plant is fed into the desalination plant (thermal). Backwash of the sand filter is fed into the main treatment facility. Total cost of treating the effluent for the said unit is approximately Rs. 4.5/ cu.m. of effluent including RO plant cost.
AIR POLLUTION CONTROL: Arvind Limited has switched from liquid fuel to Natural gas for all their heating& steam requirements in order to avoid the air pollution.
SOLID WASTE MANAGEMENT All the units believe in waste minimization measures. The plant is provided with adequate sludge Dewatering facilities with decanter centrifuges. De-watered sludge is dried in solar evaporation pans for further volume reduction. Waste oil generated in all the units is recycled. Polythene liners, discarded containers are disposed-off to the respective buyers.
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X.
ACCREDITATIONS
ISO 9001:2000 by BVQI (India) Pvt. Ltd., Mumbai-India, for Manufacture and Supply of Denim Fabrics. The ISO 9000 family of standards is related to quality management systems and designed to help organizations ensure that they meet the needs of customers and other stakeholders [1] while meeting statutory and regulatory requirements related to the product. The ISO 9001:2000 version sought to make a radical change in thinking by actually placing the concept of process management front and center ("Process management" was the monitoring and optimisation of a company's tasks and activities, instead of just inspection of the final product).
IS0 14000: Provides environment management standards to help organisations minimize their negative impact on the environment Environment Management System (EMS) mandatory Certification carried out by third party Focuses on process as in case of ISO 9000
Oeko-Tex Standard 100 by Shirley Technologies Ltd., UK, for Black and Indigo dyed denim fabrics, black / indigo printed denim fabric –including stretch denims. The Oeko-Tex® Standard 100 is a globally uniform testing and certification system for textile raw materials, intermediate and end products at all stages of production. The tests for harmful substances comprise substances which are prohibited or regulated by law, chemicals which are known to be harmful to health, and parameters which are included as a precautionary measure to safeguard health.
“Skal International Standards for Sustainable Textile Production” by Control Union Certifications, The Netherlands, for Processing of organic cotton.
“Global Organic Textile Standards”, Control Union Certifications, The Netherlands, for Processing of fibres from certified organic agriculture.
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Levi’s strauss Laboratory Certification by Levi Strauss & Co., Test Methods and conditions set forth, Denim Laboratory, The Arvind Mills Ltd.
ISO-17025 NABL – National Accreditation Board for Laboratories, Delhi, India, for Chemical & Mechanical disciplines of testing.
Premier Accreditation Scheme by Marks & Spencer, Test Methods and conditions set forth, Laboratory, Shirting Division Business, The Arvind Mills Ltd.
Liz Claiborne Int’l Ltd., Testing audit performance, Laboratory, Shirting Business Division, The Arvind Mills Ltd.
Labs certified by dupont
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XI.
REFERENCES
Fabric science –Glock and Kunj
Fabric Finishing – J T Marsh
Textile Science - B P Corbman
Textile Science – Tortora
WEB-REFERENCES
www.arvindmills.com
www.garmento.org
www.denimology.com
www.cottoninc.com
