contamination controlled cotton & yarn

Contamination Controlled Cotton Yarn 2012

Produced By Mr. Sunil Kumar Sharma Published in Spinning Textiles Magazine, Vol.6, Issue .6, Nov. – Dec. 2012 Edition. And in “The Indian Textile Journal, Vol. 123, August 2013 Edition

Abstract : - Indian cotton popular as most contaminated & unclean cotton in world.

“ITMF” - Survey results 2011 shows that Indian cottons described as “most

contaminated” cottons in world. Some times the level and type of contamination in

cotton bales shocked to everyone. Spinners are taking many steps for fighting with

this problem but still it is unresolved matter for all cotton processers. Contamination

complaint in cotton yarn is a major customer complaint in recent time and spinners

either pay huge amount for settle claims or they expend lot of money & manpower to

remove the contamination from cotton. Studies show that contamination complaints &

claims shares approx 15 % of total yarn complaints. Now days when labour shortage

is also become a major issue for spinning mills, fighting with contamination problem

become more difficult as it’s require huge labour engagement for contamination

removal. Yet there is no established measurement & monitoring systems available at

various stages of cotton processes.

The object of this article is to describe origin, kind of contamination and how to

control it, establishing various measurement & monitoring systems throughout the

cotton processing from it’s origin to spinning stage. A broad road map presented for

creating awareness among the entire stakeholder’s for dealing with contamination

problem. By adopting these systems ginners may produce “Contamination

Controlled Cotton” & Spinning Mills may produce “Contamination Controlled

Yarn” for contamination sensitive end use.

Origin & kind of contamination in cotton : - The source of contamination spread in

very wide spectrum, added into each processes of cotton growing to cotton Spinning.

Contamination in raw cotton according to their origin can be described as Chart - 1 : - Chart - 1 : Kind & origin of contamination

Kind & origin of contamination Cotton Related (vegetable)

Fabric made of Strings made of

Organic material

Inorganic materials

Chemical compounds

Honeydew Leaves Steams Bark

Woven Plastic Plastic bags Jute Synthetic or manmade

Woven plastic Plastic rubber Jute Cotton

Feathers Grass Paper Leather

Rust Metal Wires

Oil Grease Rubber Print Colour



Seed coat fragments fabric cloths Tar Fig.- 1 : Contamination Removed from Cotton Bales.

Cotton growing field, Storage & transportation : - During picking, storage &

transportation of raw cotton farmers normally use hessian bags or HDPE bags, the

threads pieces of these begs added with cotton and significantly contribute for

increasing contamination level. Part of birds feathers, insects, mosquitoes, hairs, dust,

small stone pieces etc may also added during these processes as cotton trade in

multifold manner in India. It is assumed that some pesticides & chemical fertilizers

also affect the basic colour of raw cotton fibre. Usually it is not visible at grey stage of

raw cotton, yarn and grey fabric, it’s appear only after processing in dye-house as

pink or green spots in fabric. However it is not established fact and researches are still

continue for identifying the exact reason for pink & green spots after bleaching.

Ginning & Pressing : - Ginning & pressing factories are the highly contributing

place for cotton contamination. In Ginning & pressing sand, stone pieces etc. added if

raw cotton is unloaded at place where concrete platform is not available. Use of



HDPE bags for various purposes contributed for increasing contamination level.

Workers engaged in ginning & pressing operations may also responsible for addition

of contamination level. Many times by mistake or negligence workers left their

personal belongings such as hair bands, small handkerchief, chapels, pocket holdings,

key chains, tobacco gutkha pouches etc. in cotton. These contamination breaks into

thousands of small pieces during ginning & spinning processes. Some ginners marked

cotton bales by permanent colour markers which leave there impression on raw

cotton.

Spinning : - In spinning mills due to higher temperature & humidity workers hairs

frequently fallen and added into process material. Use of HDPE bags for various

purposes in spinning mills is also responsible for increasing contamination level.

Devil HDPE : - Lower cost, higher life cycle, light in weight easy to carry &

maintain these specialties of HDPE material increases it’s use day by day. Presence of

HDPE in throughout the cotton supply chain become sever problem for textile

industries as small – small HDPE fibres or thread pieces added into each & every

process of cotton supply chain which is very difficult to remove, especially white

HDPE threads. Even new generation cotton contamination sorters & electronic yarn

clearers are also not so much competent to remove it.

Contamination Control Systems : -

TMC Rated Ginning & Pressing : - “Technology Mission on cotton - TMC”: TMC

star rating initiated by Govt. of India, ministry of textiles for modernization of ginning

& pressing factories now become a benchmark for Raw cotton processing. This is

unique system in world for grading of ginning – pressing units based on it’s available

machineries, infrastructure, management practices and additional qualification for

upgrading the raw cotton processing facilities. The concrete platform for keeping the

raw cotton & direct automatic feeding to ginning machines & pressing is mandatory

requirement for TMC rating. By conducting several studies now it has been

established that cotton processed through “TMC” plant is having less contamination



level. The list of TMC grade assigned ginning & pressing factories available on

Textile Committee’s website.

Controlling at Ginning & pressing stage : - Ginner should ensure following systems

for better contamination control. Spinning mills should also pressurize ginners for

strictly follow these system when they purchase cotton bales : -

1. Ginning & pressing units should be TMC rated. Full Concrete platform &

automatic cotton feeding system must require.

2. Ginner should pressurize & ensure that farmers & traders should not use HDPE

material for cotton storage & transportation. Ginner should also ensure that these

should not be used at their end too.

3. Pre-cleaner & post-cleaner machines should run in ginning factories so heavy

particles removed at ginning stage itself.

4. Ginner should create awareness for “Contamination” among their lobour for

taking proper care and remove visible contamination.

5. Cotton bales should be covered with cotton cloths only.

6. Cotton bales should not be marked with colour markers. Cotton cloth label or

thick printed papers may be used for bales identification.

7. It is advisable to put “On-line Cotton contamination sorter - CCS” before

pressing machine for better performance.

Controlling by spinning mills : - At the time of purchasing raw cotton usually

spinners are more concern for cotton quality parameters only and not addressing

contamination issue properly as this is not affecting working & yarn characteristics.

But ultimately it is related with their end product Quality. Monitoring by customer at

supplier end always gives better results and effective control. Hence at the time of

selection & purchasing cotton bales, spinners should also ensure above mention points

at ginner stage. This will definitely create a better environment for producing

contamination controlled cotton as well as spinners will also get better quality cotton.

Before purchasing of cotton bales spinners must visit the ginning factories and should

ensure all above guidelines suggested for ginning & pressing units. If require it must



be implemented in a time frame horizon. Ginning unit which follows these guidelines

should be selected in approved vendor list. An appreciating premium may pay at

initial stage for motivating the ginners for adopting these systems. Once systems

adopted & implemented, it will pay you lifelong.

Cotton bales iron strips, GI wires or plastic strips should be removed outside the

blow room and workers engaged for this work should also be educated for pickup all

small pieces of iron or plastic strips before shifting cotton bales for lay-down or for

mixing bin. Two cotton ropes may be used for tie the open loose bales for shifting

bales to blow room.

On-line Contamination control systems for Spinning Mills : - Following hi-tech

online monitoring systems available for detection & removal of contamination from

cotton & yarn : -

Cotton Contamination Sorters (CCS) : - On-line cotton contamination sorters become necessary part for cotton spinning mills. CCS may loop into blow room line just before carding feed. Cotton Contamination sorters analyze the cotton moving in the illuminated zone by the fluorescent lights. The detected contamination is ejected out by the nozzle driven by the Electro Valve using the compressed air. The continuous running contamination collection fan sucks the ejected material and thrown into the collection bag. User may set size and contrast of contamination in system PC as per their end use requirement. An average ejection in range of 1500 - 2000 per hours is a reasonable setting for contamination removal.

Fig. -2 : Basic principles of Cotton Contamination Sorter.



Electronic Yarn Clearer – Latest new generation Electronic Yarn Clearers are also

equipped with foreign matter detection & removal facilities. Colour foreign matters

measures against the contrast between the yarn body and foreign matter. The signal

which is generated by the foreign matter is defined as the intensity of the foreign

matter. The intensity of foreign matter depends on change of the light reflection.

Electronic yarn clearers may be set according to length of foreign matter and

contrast intensity. Contrast intensity more than 20 % and defect length more than 2

cm. to be removed for a reasonable Quality yarn. Fig.3 shown foreign matters

removed by electronic yarn clearers. Fig. 3 : Foreign matters removed from yarn through Electronic Yarn Clearer.

Manual Sorting : - It is most effective method for removing contamination in blow

room at the time of bale opening. Usually 1.5 – 2.0 bales /shift / worker to be

allotted for manual sorting where pre-opened bales feed into blow room line.



In direct bale feeding system at-least four no. of persons to be engaged at bales

lay down i.e. one each both side of bales lay down in forward move of belndomat /

uniflock and one each both side to backward move.

At-least one person round the clock to be engaged for contamination sorting

from CCS ejected material for each collection point.

Monitoring & measurement of Cotton Contamination : - Monitoring &

measurement of contamination in tangible form is very – very difficult as these are

seldom occurring & occur in different form & shape. Light weight & dark colour

contamination is very serious for yarn & fabric which multifold after ginning &

spinning operation, while heavy particles such as stone, metal pieces, heavy

substances may causes damage to spinning machineries or fire incidence.

Measurement of raw cotton contamination cannot be obtained by applying one

simple system. Therefore contaminations are being measured through by weight &

by number both methods. Following methods may be helpful for establishing trend

for cotton contamination : -

1. Manual checking of Per bale contamination : - Usually this method adopted

where cotton is feeding into blow room line through manual operation. In this

method cotton bales of different Lot’s, station or suppliers are being thoroughly

inspected manually for contamination and removed contamination are classified

by numbers and by weight per bales. This method is very appropriate for

grading the cotton bales contamination according to supplier / station & variety

wise. Mills equipped with automatic direct bale feeding system may adopt this

method for contamination grading as random sampling basis, prior to use any

new supplier lot.

2. Overall mixing contamination level : - This method used for monitoring the

overall trend of contamination in running mixing per shift or per day through by

weight method. Overall contamination removed throughout the shift collected

by labour engaged for contamination removal either it is from manual bale

opening system or it is from direct bale feeding system. Total removed



contamination weighted and divided into the no. of bales consumed and

calculated as Contamination / Bales in Gms.

3. Cotton Contamination sorters : - Avg. No of ejection per minutes/Hrs in a shift

or day by the “CCS” to be monitor on daily basis. If there is significant variation

observed in ejection level trend it should be diagnose properly and corrective

action to be taken accordingly. Similarly ejected contamination also to be

analyzed and monitored as by weight method w.r.t. blow room production (i.e.

Contamination in Gms for 1000 kg. cotton). Operating & Cleaning systems

suggested by CCS suppliers should follow strictly for consistent & better

performance of CCS.

4. Foreign Matter electronic yarn clearers : - Count wise foreign matter cuts per

100 / km. to be monitored regularly. This will provide trend for contamination

level in ring yarn. This is the final action point for contamination monitoring in

spinning division hence according to foreign matter cuts level user may set CCS

setting in blow room and EYC setting at autoconer.

5. FD / km. through Uster Evenness Tester -5 : - The Uster Tester -5 provides a

new sensor i.e. “FM sensor” that is able to measure foreign fibres in yarn in

order to extent the analysis possibilities in the laboratory. Besides the

measurement of coloured foreign fibres, the sensor can also differentiate

vegetable matter. The sensor FM provides the following results : -

a. Foreign Matter dark. FD : - Coloured foreign matter, the number of FD i.e.

foreign matter dark may be divided into 23 classes. The number FD/Km. in

the result table gives the overall number of foreign matters.

b. Vegetable matter : - Vegetable matters are residual of plants. In contrast to

artificial matter like plastic, vegetable matters has a higher mass increase and

can therefore be separated from the other foreign matter. As they consist of

cellulosic material, it is assumed that vegetable matter can be dissolved or

bleached in subsequent processes after spinning.



User may classify foreign matter classes as their own requirement and obtain

report accordingly. A sample test report given here with for ready reference

in chart-2 & chart-3: -

Chart – 2 : UT-5 Test Report for FD / Km.

Chart – 3 : FD & vegetable matter classification through UT5



5. Classimat Uster Quantam : - Classimat Uster Quantam also provide the

classification for foreign matter defects with 21 classes, this report also helps

user to set right adequate electronic yarn clearer setting and for monitoring of

foreign matter defects. User may also configure different classes according to

their own requirement.

6. Consolidation of all data : - After conducting all above measurement &

monitoring activities through different channels and at various stages, user

should prepare a consolidated report in which contamination level at different

stages may be compiled in a single page report, so overall performance of

different processes may obtained at a glance. A model report is shown in chart-4

for ready reference : - Chart – 4 : Consolidated Report for Contamination level at different stages

Date : - DD / MM / YY Shift : -

Sr. No. Description Contamination level A. Blow Room 1. Manual removed contamination by weight (in Gms) 2. Manual removed contamination by number ( Total Cont. in Numbers) 3. Hairs 4. Jute / Hessen 5. Dyed fabric / Fibres 6. Colored PP / HDPE / Synthetic material 7. White PP / HDPE / Synthetic material



8. Stone / Sand / Wood 9. Metal pieces 10. Dirty cotton / Waste B. Cotton Contamination Sorters 1. Avg. No. of ejection / Hrs 2. Total Contamination ejected (in Gms) C. Foreign Matter electronic yarn clearers 1. Count (Ne) 2. Total Foreign matter cuts / 100 km. 3. Total Foreign matter cuts / kg. of yarn D. FD / km. through Uster Evenness Tester -5 1. FD / Km. 2. Vegetable matters / Km. E. Classimat Uster Quantam 1. Objectionable FD defects (i.e. A4A3,B4,B3,C4,C3,C2, D4–D1, E4-E1, F) 2. Total FD – All classes / 100 Km.

Social Responsibility : - India is the second largest producer of cotton & yarn in

world. We should realize this fact that characteristics wise our cotton is far better but

we are spoiling it by adding contamination in different stages by knowingly or

unknowingly. Improvement of Indian cotton Quality with respect to contamination

level is the responsibility of all cotton grower, traders & processer. By taking

appropriate initiatives and contribution whatever possible at our end, we can get

desire respect & value for Indian cotton & yarn in textile world and may save lot of

money & manpower that involve for removing contamination in downstream

processes. This is also an important fact that many times contamination in cotton

causes wears - tears & fire incidence in spinning, which affect huge financial losses &

heavy detention in productivity. Hence by taking proper care & awareness among all

stakeholders related with cotton trade we can contribute a lot for our country and

society.

Conclusion : - Characteristic wise Indian cotton is among best available cotton in

world, most suitable for medium count range, however the contamination level

present in it downgraded the overall rating. Now this is the time to take serious

affords to resolve this burning problem before it hit our competitive targets. The

concept behind “Contamination Control cotton” & “Contamination Controlled



yarn” is to provide globally competitive Indian cotton & yarn w.r.t. lower

contamination level by improving whole supply chain from origin to finished yarn.

Various monitoring & measurement systems in different stages of cotton processing,

applying with various Quality monitoring tools explain here for better control over.

Ultimately it is our social responsibility too for improving Quality of Indian cotton &

yarn for competitive global market, increase in productivity of spinning and

downstream is the byproduct of this complete process.

References : -

www.itmf.org

Vetal Scan – Instruction Manual.

Uster Tester 5 – Application Handbook.

Produced by : Mr. Sunil Kumar Sharma, Manager – QAD,

Mobile No. : – 09552596742, 09921417107

E_mail : - [email protected] Loknayak Jayprakash Narayan Shetkari Sahakari Soot Girni Ltd.

Kamalnagar, Untawad – Hol, Shahada,

Tal. : - Shahada, Dist. : - Nandurbar (MS)

Pin : - 425409