reports on cotton contamination

7/28/2019 Reports on Cotton Contamination

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Contaminationand itssignifcanceto theAustralianCotton Industry


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Acknowledgements

This project was initiated by CSIRO Materials Science and Engineering (CMSE) and wassupported nancially by CMSE and the Australian Co on Catchment and CommunitiesCo-operative Research Centre (CRC).

The author gratefully acknowledges the support provided during this project bythe Australian Co on Ginners Association (ACGA),The Australian Co on ShippersAssociation (ACSA), PT APAC INTI CORPORA, Mr.V ayshankar, and the individualgins that participated in this survey. The assistance of Susan Miller in analysing thecontaminants and Stuart Gordon in compiling this report is also gratefully acknowledged.

Correspondence on this report should be addressed to:

Mr Marinus H. J. van der Slu sCSIRO Materials Science and Engineering,Belmont, Victoria 3216,Australia.

Email rene.vanderslu [email protected] 61 3 5246 4000Fax 61 3 5246 4057

2009 Cotton Catchment Communities CRC. This book is copyright. Except as permitted under the Copyright Act 1968(Commonwealth), no part o this publication may be reproduced by any process, electronic or otherwise, without the specifcwritten permission o the copyright owner. Neither may in ormation be stored electronically in any orm whatsoever withoutsuch permission. Enquiries should be address to:

Cotton CRC

Locked Bag 1001Narrabri NSW 2390

Disclaimer: Any in ormation provided in this book is intended as a source o in ormation only and is not advice, endorsement orrecommendation.


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Table o Contents

Executive Summary ................................................................................................ 5

Glossary of Terms ................................................................................................... 6

Introduction ............................................................................................................. 7

ITMF Contamination Surveys ............................................................................. 14

All Co ons ................................................................................................... 14

Australian Co on ....................................................................................... 19

Limitations of the ITMF Data ................................................................... 19

The Australian Co on Mill Survey ................................................................... 21

Detailed Assessment and Managementof Contamination in Australian Co on ............................................................ 22

Contamination in Modules ....................................................................... 22

Contamination in Bales ............................................................................. 25

Comparison of Contaminants in Modules and Bales ........................... 28

Conclusion .............................................................................................................. 29

References ............................................................................................................... 30

Appendix 1 .............................................................................................................. 31


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Cotton modules waiting to be transported to the gin

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ContaminationinAustralianCotton


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Contamination, even if it is a single foreign bre,can lead to the downgrading of yarn, fabric orgarments to second quality or even the totalrejection of an entire consignment and is thus avery important bre parameter.

The Australian Co on CRC Mill Survey ratedcontamination as one of the most favourable

bre properties of Australian co on. However,there has been concern that incidences of somecontaminants are increasing. This was supported by International Textile Manufacturers Federation(ITMF) Contamination Survey ndings from 1999to 2005, which showed an increase in the numberof contaminated Australian co on bales delivered

to overseas spinning mills. The major sourceof contamination in Australian co on has beenorganic ma er such as leaves, feathers, paper andleather followed by string and fabric made fromplastic lm and from jute and hessian.

In order to overcome the limitations of the ITMFcontamination survey and as a rst step towardseradicating contamination levels in Australianco on, the Australian co on industry throughCSIRO Materials Science and Engineering (CMSE)

with the support of the Co on Catchment andCommunities Cooperative Research Centre (Co onCRC) conducted a survey from 2006 to 2008.Activities included:

Surveying Australian ginners during the2006, 2007 and 2008 ginning seasons to determinethe degree and type of contamination found inco on delivered in modules to the gin yards.This is aimed at identifying the magnitude of theproblem of foreign ma er in Australian co on andgives a be er sense of how contamination eventsoccur in the eld and gin.

Cooperation with a large overseasspinning mill (Apac Inti Corpora) that uses asizeable proportion of Australian co on in its milllaydowns, to accurately assess the extent and theamount of contamination being sent in Australianco on bales.

Brie ng growers and ginning companieson survey outcomes and together identifyingand prioritising actions to minimise or eradicatecontamination.

Inclusion of contamination preventionmeasures in Best Management Practice (BMP) forgrowers and ginners.

The survey found that the majority of contaminantsfound in modules were metallic pieces fromharvesters, module builders and from thetransportation of modules to the gins. The majorcontaminant found in co on bales were pieces ofcloth from either woven or kni ed rags or clothing invarious colours made from either co on or polyesteror blends thereof.The survey showed that in 2006/07 Australian co on

contained the lowest levels of contamination of allgrowths imported by the spinning mill. The dataalso revealed that contaminants found in Australianco ons major competitors such as Brazil, West Africaand some regions in the USA are also decreasing.

There is no doubt that the continued and increasingpresence of foreign ma er in raw co on is a seriousissue for textile processors and it is pleasing tonote that the amount of foreign ma er found inAustralian co on bales continues to be small

relative to other growths. The challenge for theAustralian co on industry is to provide co on withzero contamination. In response to this challenge,the Australian ginning sector is implementing BestManagement Practices (BMP) and the industry iscurrently investigating the possibility of integratingdecontamination systems into the gin. Thesemeasures will reduce and possibly eliminate theoccurrence of foreign ma er in modules delivered tothe gin yard and subsequently the bales delivered tothe spinner.

Marinus H.J. van der Slu s

rene.vanderslu [email protected]

May 2009

Executive Summary


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Glossary o TermsBale 227 kg (500 pounds) of pressed and boundco on bre.

Bale Lay-Down - A row of bales opened and

blended to ensure a consistent and homogeneous blend.

Carding Carding individualises and partiallyaligns the bres, and then condenses the bres intoa single continuous strand of overlapping brescalled sliver.

Short bres and bre entanglements (referred to asneps) are removed during carding.

Colour Colour is a primary indicator of grade.Discolouration is due to range of in uencesincluding trash and dust content, rain damage,insect secretions, UV radiation, heat and microbialdecay. Colour in co on is de ned in terms of itsre ectance (Rd) and yellowness (+b), which aremeasured by a photoelectric cell.

Contamination The International TextileManufacturers Federation (ITMF) identi es 18sources of contamination in its bi-annual survey ofspinning mills.

Drawing Drawing is the process where the bresare blended and straightened. The drawing processalso improves the uniformity of the sliver.

Dyeing Ability A description to describe howevenly or unevenly a co on dye is taken up by yarnor fabric.

Extension Also called elongation, this value isthe percent extension (elongation) of a bre bundle before it breaks.

Fineness Co on neness is described in terms oflinear density or weight per unit length of bre, theunit for which is usually milligrams per kilometre(mtex).

Ginning The separation of bre (lint) from co onseed.

Grade Historically grade is a subjective

interpretation of bre colour, preparation and trashcontent against o cial standards.

Length Uniformity An indication of uniformity oflength distribution.

Maturity The co on bre is single elongatedplant cell and maturity refers to its degree of cellwall thickening.

Micronaire Air ow measurement based on thepressure di erence obtained when air is passedthrough an accurately weighed plug of co on

bres. Originally calibrated to give neness(in micrograms per inch) the method actuallymeasures speci c surface area (surface area perunit mass) and therefore re ects a combination ofthe samples neness and maturity.

Modules Harvested co on compacted into a big square (about the size of a bus) which is then

transported to the gin for ginning.Nep Neps are bre entanglements that have ahard central knot or nucleus that is detectable.

Opening, Blending and Cleaning Opening, blending and cleaning are the rst operations atthe spinning mill.

Roving In preparation for ring spinning, thesliver needs to be condensed into a ner strand,known as a roving, before it can be spun into ayarn. The roving frame draws out the sliver to athickness of a few millimetres and inserts a smallamount of twist to keep the bres together.

Short Fibre Content (SFC) The most commonde nition of SFC is the proportion by mass of breshorter than 12.7 mm or one half inch.

Size Substance applied to yarn which improvestheir strength sti ness and smoothness whichimproves weaving performance.

Spinning Ability There is a wide range of indicesused to measure spinning ability. The mostcommonly applied index is the number of (yarn)ends down per thousand spindle hours.

Staple Length The length of a typical portionof the bres in the samples as determined by theclasser or High Volume Instrument.

Strength The strength of co on bres is usually

de ned as the breaking force required for a bundleof bres of a given weight; the test value being ameasure of breaking stress or tenacity, expressedin terms of grams per tex (g/tex).


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Trash Any material other than co on bre in asample is referred to as trash or non-lint content.Trash in co on usually consists of leaf and otherparts of the co on plant.

Warp Yarns or threads that run lengthwise in awoven fabric.

Yarn formation, or spinning - The process ofconverting co on bres into a yarn structureinvolving a number of processes. There are threemain technologies used commercially to produceco on and other short staple yarns:

Ring spinning:

The technology for ring spinning was perfected by the end of the 19Th century and became thestandard for manufacturing short staple yarnsworld wide and it continues to be the mostdominant spinning system. The majority ofAustralian co on is spun into yarn using thisspinning system. Ring spinning is the processof further drawing out roving to the nal countneeded, inserting twist to the bres by meansof a rotating spindle and winding the yarn on a bobbin. These processes take place simultaneouslyand continuously.

Open end (Rotor) spinning:This technology was introduced in the mid 1960sand together with ring spinning accounts for over95 % of short staple yarn produced world wide.

Sliver is fed into the machine and combed andindividualised by the opening roller. The bresare then deposited into the rotor where aircurrent and centrifugal force deposits them alongthe groove of the rotor where they are evenlydistributed. The bres are twisted together as theyarn is continuously drawn from the centre of the

spinning rotor. The resultant yarn is cleared of anydefects and wound onto packages.

Air jet spinning (vortex):This technology was introduced in the early 1980s.Sliver is fed into the machine and is further drawnout to the nal count and twist is inserted bymeans of a rotating vortex of compressed air. Theresultant yarn is cleared of any defects and woundonto packages ready for use in fabric formation.

Winding In the case of ring spun yarns, thewinding process is a necessity and the nalprocess in a spinning mill. The winding process isneeded to transfer the yarn from small bobbins to

larger packages and to remove defects in the yarn.This will ensure more e cient processing duringfabric formation. Packages from the rotor and air jet spinning systems can also be given a furtherwinding operation if required.

Yarn count The count of a yarn is a numerical

expression of its neness, or weight per unit length(linear density). There are two main systems usedto determine linear density.

1. The indirect system known as EnglishCo on Count (Ne) is based on the number of 840yard lengths in one pound weight of yarn. Thehigher the English Co on Count value, the ner theyarn, i.e. the more yarn length in one pound.

2. In the direct system, the yarn count is

determined by measuring the number of gramsper thousand metres of yarn and is denoted as Tex.The higher the Tex value, the heavier the yarn.


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IntroductionContamination, even if it is a single foreign bre, can lead to the downgrading of yarn, fabric orgarments or even the total rejection of an entire batch and can cause irreparable harm to the

relationship between growers, ginners, merchantsand textile and clothing mills (see Figure 1 & 2).An International Textile Manufacturers Federation(ITMF) study in 2001 [1] reported that claims dueto contamination amounted to between 1.4 3.2%of total sales of 100% co on and co on blendedyarns. A study conducted in Pakistan estimatesthat contamination of co on is responsible for anannual loss of US$ 1.4 billion to US$ 3 billion inexport earnings [15].

Most contamination arises from impurities beingincorporated into the bale as a result of humaninteraction during harvesting, ginning and baling.In order to convert a bre into yarn, co on passesthrough a large number of processes in a spinningmill. A large number of machines mechanicallyreduce the size of most foreign ma er clusters intoa large number of individual foreign bres. These

bres can remain undetected under normal millprocessing conditions and only become noticeablewhen the production process is interrupted, bya spinning end break or when the yarn is usedto make up fabric and the fabric is subjected tonormal quality control inspection. Contaminationrepresents a signi cant cost to spinning mills andit is thus very important to detect and eliminatecontamination as early in the process as possible.This has led to the implementation of a range ofmethods to cope with contamination.These include:

The rst step, and the most logical, is toavoid or minimise the use of co on from originsthat are known to be contaminated. Contaminationsurvey results and the practical experience of millsta and industry hearsay should be taken intoconsideration when purchasing co on. Ideally,allowable levels of contamination should bestipulated in co on contracts with ginning andmerchant companies. Ginners and merchantscould use existing ITMF survey information or beencouraged to develop their own contaminationscreening protocols in order to assess thecontamination risk of their co on.

Spinning mills situated in countries wherelabour costs are comparatively low employ largenumbers of people to patrol the bale laydown and

remove contamination from bales before co on isfed into the blowroom line by the bale opener (seeFigure 3).

A small number of spinning mills are ableto manually check and remove contaminationfrom every bale of co on before it is repacked andreleased for processing in the mill (see Figure 4& 5). This manual sorting is either done directlyfrom the bale or the bale is rst opened using a bale opener with a spiked la ice to open the co onprior to manual sorting. The cost for this manualcleaning is estimated at 3.1 to 4.4 US cents per kgof lint depending on the level of contamination[12].

Although manual intervention is helpfuleven low labour cost spinning mills have come torealise that it is not always su cient as generallyonly the bigger contaminants are removed. Hence,they are equipping blowrooms with systems fordetection, separation and measurement of foreignmaterial (see Figure 6). These systems detectcontaminants using acoustic, optical and coloursensors that monitor the material as it ows (isprocessed) through the machinery. When a sensoris activated by a contaminant it is measured(registered) and, depending upon the system,mechanically removed via an alternate material

ow outlet. These systems are normally installedat the beginning of the blowroom line beforethe nal cleaning stage, although a number ofspinning mills also install a second machine at theend of the blowroom line [11]. It is estimated theinstallation of foreign ma er detectors has cost thespinning industry in excess of $US150 million overthe past 10 to 12 years and that these detectorsinspect approximately 30 - 35% of the global co onconsumption [2].

It is estimated that there are approximately 3500to 4000 systems installed worldwide [3]. However,studies show that these systems only remove 60 75% of contaminants [4, 11]. The inclusion ofmetal detectors in blowrooms has been a standardfeature for many years.

Careful control of waste recycling andmaintenance in the spinning mill to avoid the

accidental introduction of contaminants andforeign bres to the process.


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Figure 1 Contaminated Yarns(photo courtesy o CSIRO Materials Science and Engineering)

Figure 2 Contaminated Fabric(photo courtesy o CSIRO Materials Science and Engineering)


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Figure 4 Manual removal o contaminants rom cotton be ore release to spinning mill (Indonesia)

Figure 3 Operators patrol a bale laydown to remove contamination rom bales (Indonesia)

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Figure 6 Blowroom equipped with Jossi detection systems (photo courtesy o Jossi Systems AG)

Figure 5 Manual removal o contaminants rom cotton be ore release to spinning mill (India)

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There are devices on the market that can be added to the carding, drawing and lappingmachines, which detect foreign bres (of a di erentcolour) and stop the machine for removal by theoperator.

Equipping winding machines with yarn

clearers that detect and remove foreign ma erfrom the yarn before it is wound onto packagesand delivered to the kni er or weaver (see Figure7). The types of contamination and the e ciency ofremoval depend on the sensors employed in thesesystems, with modern clearers able to detect the

nest defects not visible by the human eye. A largenumber of contaminants will lead to a number ofstoppages which will result in loss of production,increased labour costs and increases in waste [5]. Itis estimated that approximately 40% of yarn spunin China is cleared using yarn clearers that detectand remove foreign ma er versus 75% of yarn in therest of the world [3, 5]. However, these systems onlyremove 80 to 85% of contaminants [2].

Equipping modern, high productionspinning machines, such as Air Jet and Open end(Rotor) spinning with yarn clearers that detect andremove foreign ma er. These clearers are onlyable to remove the major contaminants to avoida dramatic drop in e ciency [5}. It is estimatedthat only 20% of the yarns spun on the Open endspinning machine are cleared using yarn clearersthat detect and remove foreign bres [3].

Installing Ultra Violet lights in the packingand inspection departments to detect chemical/oilysubstances and foreign bres such as polyester andother synthetic man-made bres that uoresce (seeFigure 8).

If a spinning mill is vertically integratedthrough to fabric production the possibility further

exists to remove contaminants manually fromthe fabric before it is dyed and nished. This ishowever very time consuming and expensive withsome estimates at $US4/100 meters [5]. Furthermore,contaminants cannot be removed from kni edfabrics as this will cause holes and in woven fabricit is very di cult to remove contaminants from thewarp direction due to the presence of size.

Chemical treatment such as bleaching/scouring in preparation for dyeing reduces the

problem of contamination but adds further cost inprocessing which is not always acceptable to allcustomers.

In the past there have been a empts toincorporate contamination removal systems inthe ginning process. There are currently twosystems operating successfully in Greece andten in India. As the major ginning equipmentsuppliers, showed li le interest in incorporatingthese systems into their ginning equipment, the

manufactures are not promoting or conductingfurther R&D [13, 14, 17].

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Figure 8 Installation o Ultra Violet lights in the packing and inspection departments

Figure 7 Yarn clearer to remove oreign matter rom yarn in winding and open end spinning(photo courtesy o CSIRO Materials Science and Engineering)

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ITMF Contamination Surveys(a) All Co ons

In order to quantify and highlight the presence of

contamination in co on lint the ITMF conducts asurvey of co on users (spinners) on the amount ofcontamination found in world growths. The surveyhas been conducted in its current format since1989 on a biannual basis. In the survey spinnersare asked to rate the degree of contamination inco on lint according to 16 categories of foreignmaterials listed in Table I as to whether they were

Table I ITMF Contamination sources [6]

1 Fabrics made of woven plastic

2 plastic lm

3 jute/hessian

4 co on

5 Strings made of woven Plastic

6 plastic lm

7 jute/hessian

8 co on

9 Organic ma er leaves, feathers, paper, leather, etc

10 Inorganic ma er sand, dust

11 rust

12 wire, metal13 Oily substances/chemicals grease/oil

14 rubber

15 stamp colour

16 tar

non-existent/insigni cant, moderate or serious.

(The perceptions with regard to incidences ofstickiness in co on and seed-coat fragments arealso surveyed but not covered in this report.)

As one would expect the degree of contaminationvaries widely from region to region and betweengrowths. As can be seen in Table 2, the mostcontaminated co on continues to originate


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from India, Turkey and Central Asia (variousdescriptions). In contrast, as can be seen inTable 3, the least contaminated co on continuesto originate from Zimbabwe, the USA, Israel,Australia and some countries from West Africa(various descriptions) [6]. It is noted that co onthat is mechanically harvested generally has less

contamination as there is less interaction betweenhumans and the co on during harvesting andginning. It is for this reason that some spinnersand even some countries (such as Japan) use no, orvery li le, hand picked co on [16].

No growths are contaminant free, even the leastcontaminated co on has contamination levels of4-5%. Analyzing the results of the surveys since1989 one discovers that:

The perceived degree of contaminationin all growths steadily increased from 14% in1989 to 26% in 2003, although a decrease to 22%in 2005 was recorded, which was maintained in2007 (see Figure 9). It is notable from Figure 5that there is a dramatic increase in contaminationworldwide since 1993 which can in all likelihood be a ributed to the fact that spinners becamemore aware of contamination as they startedto receive complaints from fabric and garmentmanufacturers.

A further breakdown (see Table 4) reveals that themajor source of contamination in all bales continuesto be organic ma er such as leaves, feathers, paper,leather, etc., which has steadily increased from 30%in 1989 to 50% in 2003, although it decreased to40% in 2005 and 2007. It must be noted that some bales can be contaminated with more than one

contaminant. The next most prevalent contaminantis fabric and string made from co on, wovenplastic, plastic lm and jute/hessian, followed bysand and dust. The incidence of oily substances/chemicals and inorganic ma er such as rust andmetal has remained fairly consistent since 1989 .

0

5

10

15

20

25

30

1989 1991 1993 1995 1997 1999 2001 2003 2005 2007

%

Figure 9 ITMF Contamination Survey results rom 1989 to 2007 [6]


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2 1

2 4

3 0

2 5

3 0

3 0

3 8

2 5

2 9

c o o n

1 7

1 6

1 6

1 9

1 8

2 5

2 2

3 0

2 4

2 6

O r g a n

i c m a e r

l e a v e s , f

e a t h e r s , p a p e r

& l e a t h e r

3 0

2 8

2 9

3 4

3 4

3 9

3 9

5 0

4 0

4 0

I n o r g a n

i c m a e r

s a n

d / d u s t

1 6

2 0

1 9

2 5

2 3

3 0

2 8

3 7

2 9

2 5

r u s t

1 0

1 3

1 2

1 3

1 3

1 8

1 5

2 0

1 5

1 3

m e t a l

/ w i r e

1 5

1 2

1 3

1 4

1 5

1 6

1 8

2 1

1 2

1 7

O i l y s u

b s t a n c e s / c h e m

i c a l s

g r e a s e

/ o i l

1 4

1 4

1 5

2 0

1 8

2 3

2 2

2 3

1 6

1 7

r u b b e r

4

5

4

5

6

6

7

9

7

9

s t a m p c o

l o u r

1 2

1 5

1 2

1 4

1 4

1 4

1 6

1 7

1 5

1 1

t a r

3

3

2

4

4

4

6

6

5

5

N o n

E x i s t e n

t / i n s i g n

i c a n

t

8 6

8 5

8 5

8 1

8 2

7 9

7 8

7 4

7 8

7 8

M o d e r a t e

9

1 1

1 1

1 3

1 3

1 5

1 6

1 8

1 5

1 5

S e r i o u s

5

4

4

6

5

6

6

8

7

7

T a b l e 4

B r e a k d o w n o f c o n t a m i n a n t s f o u n d i n %

i n c o t t o n w o r l d w i d e [ 6 ]


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ContaminationinAustralianCotton 0

2

4

6

8

10

12

14

1989 1991 1993 1995 1997 1999 2001 2003 2005 2007

%

Figure 10 Australian contamination results rom ITMF Contamination Survey rom 1989 to 2007 [6]

(b) Australian Co on

Australian co on is generally viewed worldwideas a quality bre with low or no contaminationand is usually purchased (at a premium) withthe intention of producing high quality yarns,normally combed ring spun, for use in the weavingand kni ing sector. The results of the ITMF surveycon rm this perception with Australian co oncontinuing to be one of the best performers interms of contamination.

However, analyzing the historical Australian datafrom the ITMF surveys, one nds that while theoverall level of contamination is low, over recentyears there has been an upward trend (illustratedin Figure 10) i.e. an increase from a base level ofapproximately 5% being moderately or serious

contaminated in 1989 to approximately 13% in2005, although decreasing to 8 % in 2007.

In parallel with the world data, the major singlesource of contamination is organic ma er such asleaves, feathers, paper and leather (see Table 5).The next most damaging source of contaminationin Australian co on is string and fabric made

from plastic lm followed by string and fabricfrom co on woven fabric and jute/Hessian. Themain source of plastic lm is module covers,which is also a major issue in the USA [10]. Itis noticeable that the incidence of jute/hessiancontamination in 2007 has dropped by 50 % whencompared to 2005 which is in all likelihood dueto the change in industry practices with a largenumber of co on bales now being covered withco on bale covers [9]. Inorganic ma er and oilysubstances/chemicals remained fairly consistent

since 1989 with the exception of tar whichincreased to 13% in 2003.


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(c) Limitations of the ITMF Data

It is important to note that there are a numberof limitations associated with the ITMFContamination Survey as follows:

Participant mills make a largely subjectiveassessment of the contamination found in agrowth and moreover whether the occurrence in aparticular growth has been insigni cant, moderateor serious. As the ITMF methodology states thebasic statistical unit (the sample) of this surveyis a spinners evaluation of a given description,which it had consumed during the last 12months.

On the basis of the previous point theSurvey is unable to quantitatively measure the

number or proportion of bales actually a ected bycontamination.

Cotton bales ready or shipping

Low overall numbers of contaminationconceal higher levels of particular contaminantsas each category is given equal weighting indetermining the average contamination number.

With regard to Australian co on, only asmall number of spinning mills in our traditionalmarkets such as China, Indonesia, Thailand, SouthKorea and Japan participate in these surveys.


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C o n

t a m

i n a n

t

1 9 8 9

1 9 9 1

1 9 9 3

1 9 9 5

1 9 9 7

1 9 9 9

2 0 0 1

2 0 0 3

2 0 0 5

2 0 0 7

F a b r i c s

w o v e n p

l a s t

i c

4

0

3

2

7

7

5

6

1 3

0

p l a s t

i c l m

8

0

2

4

4

5

5

9

1 7

5


6

1 1

5

1 1

7

6

1 0

1 8

1 7

1 1

c o o n

8

7

6

4

4

1 1

8

9

1 3

5

S t r i n g s

w o v e n p

l a s t

i c

2

2

2

0

1 1

7

3

6

8

5

p l a s t

i c l m

4

2

6

0

7

1 1

5

1 2

1 3

2 7


1 0

1 3

9

1 5

2

9

2 1

2 4

1 7

5

c o o n

6

4

5

2

4

7

1 3

9

1 3

0

O r g a n

i c m a e r

l e a v e s , f

e a t h e r s , p a p e r

& l e a t

h e r

1 0

6

9

1 3

1 3

2 4

2 5

3 6

2 6

2 1

I n o r g a n

i c m a e r

s a n

d / d u s t

1 0

7

9

6

6

1 6

1 8

1 5

1 3

1 1

r u s t

2

9

5

2

1

5

8

1 2

1 7

5

m e t a l

/ w i r e

6

0

2

4

1

4

5

6

4

5

O i l y s u

b s t a n c e s / c h e m

i c a l s

g r e a s e

/ o i l

1 0

4

3

0

4

1 1

8

1 2

9

5

r u b b e r

0

2

2

0

1

2

3

6

4

0

s t a m p c o

l o u r

6

6

0

2

0

2

3

1 2

1 3

0

t a r

2

0

2

0

0

2

0

6

1 3

1

N o n

E x i s t e n

t / i n s i g n

i c a n

t

9 5

9 6

9 5

9 6

9 5

9 2

9 1

8 7

8 7

9 3

M o d e r a t e

5

3

4

3

4

7

8

1 0

1 1

6

S e r i o u s

0

1

1

1

1

1

1

3

2

1

T a b l e 5

B r e a k d o w n o f c o n t a m i n a n t s f o u n d i n %

i n A u s t r a l i a n c o t t o n [ 6 ]


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The Australian Cotton CRC Mill Survey

Figure 11 Spinners impressions o Australian cotton fbre quality (5 = good, 3 = no issue, 1 = bad) [7]

An independent survey [7] conducted by CSIRO ofover 30 international spinners that use Australianco on, surveyed in 2002 and 2003 (see Figure 11)shows the average response to their perceptionsof bre quality characteristics of Australian co on.Spinners responses indicated that contaminationwas one of the most favourable properties ofAustralian co on.

However, despite this favourable responseindividual spinning mills at the time had concernsthat the incidence of contaminants such aspolypropylene and jute string (from jute/hessian bags) was increasing. This is in line with the trendsnoted in Table 5.


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Due to the importance of contamination and the

limitations of the ITMF contamination survey andthe need for more comprehensive and objectiveinformation a comprehensive survey of not onlyspinning companies but also of ginning companieswas undertaken to obtain more accurate andthorough information on current sources and levelsof contamination.

During the past three seasons all operating ginsin Australia have participated in the survey,collecting and recording all contaminants found

in modules delivered to the module feeding areaof the gin. Gins also recorded the costs of repairand replacement of parts due to damage caused bycontaminants.

P. T. Apac Inti Corpora (herein Apac Inti) is alarge co on spinning mill situated in Indonesiathat performs a unique process at their mill;every bale of co on is manually inspected beforeprocessing and contaminants, even single humanhairs, are removed and collated. This allows fora direct measurement by weight and by type ofcontaminants exported with Australian co on.Since 2000 Apac Inti has cleaned over 200 millionkilograms of co on sourced from around the worldand has generated a large and accurate database onthe levels of contaminants found in a wide range ofgrowths.

Contaminants in Modules

Over 770 incidents of contamination were recordedfrom a total of 158,693 modules processed between2006 and 2008 (see Table 6). An incidence refersto a single contaminant. The costs quoted in Table6 refer to the cost of repairing or replacing partsdamaged due to foreign objects, but do not includethe cost of labour or loss of production. Table 7and Figure 12 show the breakdown of contaminanttype found in modules during the 2006, 2007 and2008 seasons.

The survey showed that most contamination occursduring picking and to a lesser extent in ginning.

The reason we know this is because the majorityof contaminants found in modules were metallicpieces from harvesters, module builders and fromtransportation of modules to the gins. However as

Detailed Assessment and Managemento Contamination in Australian Cotton

will be seen in the contaminants found in bales,

metallic objects are usually not a big issue forspinners as they are generally large and easilyremoved during the ginning process eithermanually or by magnets, although they cancause considerable damage to the gin. This wasfollowed by a category other, which includeditems such as mobile phones, shotgun shells, beercans, oil cans, two-way radios, hats and rubbermats. This was followed by module ropes andplastic which included plastic bags, moisture padsfrom harvesters, strapping, rakes and a siphon.

This was followed by grass and timber, which isfollowed by grease and oil which is mainly due tohydraulic oil. The fabric category includes all ragsand cloth of any description and covers refers tomodule covers (tarpaulins).

Although the gins recorded a large number ofrocks during the survey they were not consideredin this survey as they are easily removed duringthe initial stages of the ginning operation.

Examples of the contaminants removed frommodules at the gin are illustrated in Figure 13.

The introduction to the Australian co on industryof the round modules in 2010 will need to bemanaged appropriately to ensure that the plasticcovers do not contaminate the co on.


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Table 6 Details o contaminants recorded during past three seasons

STATISTIC 2006 2007 2008

No. of gins 23 27 18

No. of Modules 81,121 53,042 24,530

No. of contaminant incidents 350 127 296

Probability of contamination incident in % 0.43 0.24 1.21

Cost to all gins in $AUD 46,420 45,313 *

* No information available

Table 7 Contaminants ound in modules

Contaminants Total 2006 2007 2008

Total 773 350 127 296

Metal 364 125 57 182

Timber 43 24 13 6

Grease and oil 38 16 12 10

Fabric 21 9 24 8

Module Covers 19 11 0 8

Module Ropes 75 58 2 15

Grass 55 41 0 14

Plastic 58 24 18 16

Other 100 42 21 37


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Figure 13 Contaminants collected at gins during a ginning season (photo courtesy o DunavantAustralia)

Figure 12 Breakdown o types o contamination ound in modules during the 2006, 2007 & 2008 ginningseason


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Table 9 and Figure 14 shows the proportion by number of fragments found of particularcontaminants in Australian bales. The majorcontaminant found in bales were pieces of clothfrom either woven or kni ed rags or clothingin various colours made from either co on orpolyester or blends thereof, followed by yarnmade from either co on or polyester or blendsthereof. This was followed by polypropylene yarnin various colours, followed by followed by birdfeathers jute/hessian yarn, human hair, plasticsincluding shopping bags, lolly papers and garbage bag fragments, paper from newsprint and notepadsand metallic pieces such as nuts, bolts and wire.

Table 9 Incidences o contaminants ound in Australian consignments received by Apac Inti

Contaminants in Bales

In order to accurately quantify the degree andtype of contaminants found in Australian co on bales Apac Inti has been sending data and theactual contaminants removed from shipments ofAustralian co on, amounting to over 4,825 tonsor 21,256 bales, to CSME since December 2005(see Table 8). Apac Inti reports contaminantsas brous and non brous. During this studyfurther analysis was conducted at CSME onthe contaminants to identify the exact chemicalcomposition of the contaminants with a view toaccurately identifying their source. This was done by identifying the foreign bres on the basis oftheir melting point using the ReichertJung HotBench (with electronic stabilization).

Consignments Tons Bales

December 2005 976 4,301

April 2006 200 881

December 2006 1486 6,546

July 2007 818 3,604

December 2007 1035 4,560

March 2008 310 1,364

Table 8 Australian consignments received by Apac Inti

Contaminants Total Dec.2005

April2006

Dec.2006

July2007

Dec.2007

March2008

Total 5,140 482 96 254 583 1,600 2,125Cloth 2,100 46 0 12 9 33 2,000Yarn 1893 164 19 76 401 1,186 47Polypropylene 425 98 16 116 52 124 19Feather 277 93 7 23 30 112 12Jute 159 54 28 13 24 21 19Hair 147 15 24 7 27 70 4Plastic 113 0 1 5 35 48 24Paper 13 7 0 0 0 6 0

Metal 13 5 1 2 5 0 0Bales 21,256 4,301 881 6,546 3,604 4,560 1,364


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Figure 14 Breakdown o contaminants (by number) ound in Australian cotton shipments

Figure 15 Contaminants collected by Apac Inti or six consignments o Australian cotton since December 2005(photo courtesy o CSIRO Materials Science and Engineering)


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Figure 15 shows contaminants removed fromAustralian co on shipments. Contamination dueto jute/hessian only amounted to 3.1% of the totalcontaminants found which indicates that if careis taken with storing/transporting and removal ofthe bale covers there should be no problems withcontamination.

It is surprising considering the fact the majorityof Australian co on is processed through twolint cleaners that a large amount of vegetableplant material (total of 645.8 grams from the sixconsignments), mainly from stems and brancheswas still present in bales delivered to Apac Inti.This vegetable ma er was not included in thestudy as this will be easily removed duringthe opening and cleaning process in the co onspinning blowroom. There is also a large amountof stained co on (mostly brown/orange in colour)present in the bales which could be due to wetco on, fungal infected co on and hydraulic oiland grease.

Apac Intis data [8] (see Table 10) reveals thatin 2004/05 some 20% of Australian co on balesdelivered to the mill had some contamination,up from 14% in 1999/2000. Under the ApacInti system a single foreign bre de nes acontaminated bale. For the same period ApacInti found that 23% of Chinese, 27% of Brazilian,up to 31% of US, depending on growing region,and 66% of West African co on bales werecontaminated.

The data for 2006/07 reveals a decrease in the levelof contamination to only 12% of Australian co on bales and is the lowest of all growths imported by Apac Inti. The data also however revealsthat contaminants found in Australian co onsmajor competitors such as Brazil and co on fromMemphis, San Joachim Valley (SJV) and Fiber

Max in the US, have decreased over the sameperiod.

Further comparison with historical data fromApac Inti reveals that there was an increase inthe rate of contamination from 1.4 grams/ton in1999/2000 to 1.9 grams/ton in 2004/2005, whilstcontaminants found in Australian co ons majorcompetitors such as Brazil and some growthsfrom the USA decreased over the same period(see Table 11). However, data for 2006/07 reveals

contamination found in Australian co ondecreased to 0.6 grams/ton, the lowest of allgrowths imported by Apac Inti. Reasons forthis decrease can be a ributed to an increasedawareness of the issue of contamination in

Australia and also by the fact that the Australiancrop has been decreasing over the past few yearsdue to drought. Other countries in the worldhave shown that increased awareness can lead tosubstantial reductions in the levels of contaminationin co on bales [12]. Spinners are also willing topay a premium for contaminant free co on and

avoid growths that have a reputation for highcontamination which has resulted in growers becoming more aware of contamination.It has been suggested that if the rate ofcontamination in co on bales is less than 1.0grams/ton complaints by fabric and garmentmanufacturers will be minimal [12]. Results from this survey re ect the ITMFContamination Survey results for 2007, whichshow that the level of contamination in Australianco on reduced from 13% in 2005 to 7% in 2007(back to the levels recorded in 1999 and 2001, butstill higher than levels recorded in 1989 to 1997),whilst the degree of contamination in all growthsremained steady at 22% (Figure 9 and 10). Thisimprovement also resulted in an improvement inAustralias ranking from sixth to third in terms ofleast contaminant co on.

Sixteen percent was contaminated with jute/hessian.This is a major reduction from the 34% recorded in2005 and is due to the fact that in 2007 at least 50%of the Australian crop was covered with co on balecovering up from 31% in 2005 [9].


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Country 1999/2000(grams/ton)

2004/2005(grams/ton)

2006/2007(grams/ton)

Australia 1.4 1.9 0.6

China 2.2 3.0 *

Brazil 3.2 2.7 2.4

US 2.8 2.0 1.4

Uzbekistan * 9.1 2.4

West Africa 3.7 7.0 2.5

The data for the contaminants found in modulesand bales as presented in Tables 7 and 8 andFigures 9 and 10 shows that the major contaminantfound in bales, at 77.7% is cloth and yarn followed by polypropylene at 8.3%, feathers at 5.4%, jute/hessian at 3.1%, hair at 2.9%, plastic at 2.2% andpaper and metal at 0.25%. In contrast the majorcontaminant found in modules at 47.3% is metalfollowed by other at 12.7%, rope at 9.7%, plasticat 7.5%, grass at 7.0%, timber at 5.6%, grease/oil at4.9%, fabric at 2.7% and module covers (tarpaulins)at 2,5%.

Comparison of Contaminants in Modules and Bales

* No values available

Table 11 Contaminants by country o origin in grams/ton ound in bales shipped to Apac Inti

Table 10 Percentage o bales contaminated received by Apac Inti

Country 1999/2000(% bales)

2004/2005(% bales)

2006/2007(% bales)

Australia 14 20 12

China 20 23 -

Brazil 35 27 15

USA 26 31 15

Uzbekistan 84 86 78

West Africa 58 66 63

The di erence between the ndings can beexplained by the fact that the metal and timber will be removed during the ginning process as theyare generally large and in the case of metal will be caught by the magnets installed in the system.Grass will also be removed during the ginningprocess. Any fabric, plastic, rope and feathersthat are not detected and removed prior to theginning process will be disintegrated as the lintgoes through a large number of machines duringthe ginning process which could potentially causeproblems for the spinner.


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There is no doubt that Australian co on isunder pressure to regain market share a er anumber of years of drought. Coupled with thecurrent oversupply of co on world wide and the

emergence of other high quality growths on theexport market, the only way to make this happenis by o ering consistently high quality bre. Theindustry will thus need to continue to controlcontamination, a property which is seen as beingone of the most a ractive aspects of Australianco on. Although the amount of foreign ma erfound in Australian co on bales is small relativeto other growths, it must be borne in mind thatduring yarn formation co on is processed througha large number of machines, which can lead

to further disintegration of the contaminants,which in turn can subsequently lead to qualityand production issues. The study found that

Conclusionthe harvesting/module building operations arethe major contributors to contaminants found inmodules and the challenge for the industry is toraise the awareness of the causes and e ects of

contamination.

It is also suggested that BMPs should be developedfor harvesting and warehousing/transportation andthat contamination should be included in the On-Farm BMP to complement BMPs already in placefor ginning and classing.

It is hoped that this report will assist in raising thisawareness and convey to our customers that theAustralian co on industry takes contamination

seriously and is doing everything practicallypossible to minimise and even eradicatecontamination from its co on.

Sunset over the Namoi Valley


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1. Strolz, H. M., ITMF Co on Contamination Survey 2001, proceedingsInternationalCo on Conference Bremen, pg. 35, 2002.

2. Strolz, H. M., A fresh look at co on contamination, Asian Textile Journal, pg. 29, May2004.

3. Van der Slu s, M., Personal communication at ITMA Asia, Shanghai, China, August2008.

4. V ayshankar, M, Processing Your Product Using Australian Co on, 13thAustralian Co on Conference, Broadbeach Queensland, August 8-10, 2006.

5. Furter R., Experience with foreign ma er removal systems, Application Report, SE594, June 2006.

6. International Textile Manufacturers Federation, Co on Contamination Surveys 1989to 2007.

7. Gordon, S., van der Slu s, M. and Prins, M., Quality Issues for Australian Co onfrom a Mill Perspective, pub Australian Co on CRC, June 2004.

8. V ayshankar, M, Extraneous Contamination in Raw Co on Bales A Nightmare toSpinners, proceedings International Co on Conference Bremen, pg. 61, 2005.

9. Gordon, S. and van der Slu s M., The Use of Bale Coverings in the Australian Co onIndustry, report for CRDC, August 2006.

10. Muzzi, D., Contamination eats their lunch, Western Farm Press, December 2003.

11. Balamurugan, S., Foreign bre contamination in co on Premier Fibre Eye the rightchoice, Asian Textile Journal, pg 69, March 2003.

12. ICAC/CFC Production and Marketing of Uncontaminated Co on in Mali, (CFCICAC/32FT), April 2006.

13. Kiechl, W.,Is there an ideal cleaning point for textile contaminants? proceedings International Co on Conference Bremen, pg 143, 2004.

14. Nassiou, T., and Buchmann, B., Greek spinner goes for outstanding co on quality ,Melliand International, pg 18, March 2005.

15. h p://www.sbp.org.pk/reports/quarterly/FY05/ rst/Special_1.pdf.

16. Van der Slu s, M., Personal communication with Japanese spinners, July 2009.

17. Van der Slu s, M., Personal communication with Vetal Textiles and Electronics, July2009.

Re erences


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Photos taken by various Australian gins highlighting some of the contaminants found in modulesdelivered to the gins over the past three ginning seasons.

Appendix 1


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reports on cotton contamination

Documents