Textile testing

This PPT are used for textile engineering students, textile technology who takes textile testing courses. the PPt prepared from different books and NPTEL textile engineering web site.

1. Textile Testing I
AbdellaSimegnaw
Ethiopian Institute of Textile and Fashion
Technology( EiTEX) Bahir Dar University, Bahir
Dar, Ethiopia

2. Introduction
1

3. Quality:Fitnessforpurpose
Listofrequirementsor
specifications
Testing:determining/evaluating
thestatusofmaterialagainst
qualitystandards
Qualitycontrol:
Theoperationaltechniquesandactivitiesthatare
usedtofulfilrequirementsforqualityandensure
consistencyinprocesses.
Qualityassurance:theplannedand
systematicactionstoprovideadequate
confidencethataproductorservicewillmeet
customersatisfactionforquality
Introduction
Difference between quality , testing, quality control and
quality assurance ?

4. Despite all the costs associated with it, testing is an important tool for the
following reasons:
1.Checkingthequalityofrawmaterials:
spinning,weaving,chemicalprocessing,garment…
Bestqualityrawmaterialswillproducebestqualityproduct
ButhowdoyouknowtheRMisbestorbadquality?
2. Monitoring production
Testingsamplestakenfromtheproductionline-qualitycontrol-controlling
theproductionprocessandtheproductnottogooutofthespecified
parameters.
1.1 Reasons For Testing (Objective of Testing)

5. 3. Assessing the final product
The test is done on the final product to check whether it meets the
requirements or not
Alteration or correction of the production condition from the test
feedback is impossible
4. Investigation of faulty material
If faulty material is discovered, the cause should be identified so as to
take corrective action to eliminate faulty production in future and so
provide a better quality product.
Investigationsoffaultscanalsoinvolvethedeterminationofwhich
partyisresponsibleforfaultymaterialinthecaseofadispute
betweenasupplierandauser,especiallywhereprocessessuchas
finishinghavebeenundertakenbyoutsidecompanies.Workofthis
natureisoftencontractedouttoindependentlaboratorieswhoare
thenabletogiveanunbiasedopinion.
Cont. …

6. 5. Product development and research
Inthetextileindustrytechnologyischangingallthetime,
bringingmodifiedmaterialsordifferentmethodsof
production.
Beforeanymodifiedproductreachesthemarketplaceitis
necessarytotestthematerialtocheckthattheproperties
havebeenimprovedorhavenotbeendegradedbyfaster
productionmethods.Inthiswayanimprovedproductora
lower-costproductwiththesamepropertiescanbeprovided
forthecustomer.
Cont. …

7. Itisnotpossibleordesirabletotestalltherawmaterialorallthefinal
outputfromaproductionprocessbecauseoftimeandcostconstraints.
Manytestsaredestructivesothattherewouldnotbeanymaterialleft
afterithadbeentested.Becauseofthis,representativesamplesofthe
materialaretested
Why do we sample materials for testing?Reasons for sampling:
To minimize time requirement for testing.
to asses Risk
distractive nature of tests
Technical requirements of sampling process:
1.The sample should be a representative of the whole material
2.It should be unbiased; it should include all the varieties in the lot
Sampling

8. 1.Consignment:thequantityofmaterialdeliveredatthesame
time.Cancontainoneorseverallots.
2.Testlotorbatch:thisconsistsofallthecontainersofatextile
materialofonedefinedtypeandquality,deliveredtoone
customeraccordingtoonedispatchnote.
3.Laboratorysample:thisisthematerialthatwillbeusedasa
basisforcarryingoutthemeasurementinthelaboratory.This
isderivedbyappropriaterandomsamplingmethodsfromthe
testlot.
4.Testspecimen:thisistheonethatisactuallyusedforthe
individualmeasurementandisderivedfromthelaboratory
sample.
Terms used in sampling

9. 5.Package:elementaryunits(whichcanbeunwound)within
eachcontainerintheconsignment.Theymightbebumptop,
hanks,skeins,bobbins,conesorothersupportontowhich
havebeenwoundtow,top,sliver,rovingoryarn.
6.Containerorcase:ashippingunitidentifiedonthedispatch
note,usuallyacarton,box,baleorothercontainerwhichmay
ormaynotcontainpackages.
Cont. …

10. A.RANDOMSAMPLE:
Inthistypeofsampleeveryindividualinthepopulationhasanequalchanceof
beingincludedinit.Itisfreefrombias,thereforetrulyrepresentativeofthe
population.
B.NUMERICALSAMPLE:
Consider first a highly idealized, homogeneous strand of overlapping straight, and
parallel fibers .
Asampleinwhichtheproportionbynumberof,say,long,medium,andshort
fiberswouldbethesameinsampleasinthepopulation.
its composition is the same at all parts along its length
TYPES OF SAMPLE
displacement =d
number of fibers =n,
length of the strand = L.
If n is small, then d is large compared with l and
there are gaps between the individuals, as at (a).
If, n is large enough,d is less than l and there is
overlapping, as shown at (b).
In either event and in the general case, the number
of whole fibers in any stream is given by: n=L/d

11. C.BIASEDSAMPLE:
Whentheselectionofanindividualisinfluencedbyfactors
otherthanchance,asampleceasestobetrulyrepresentative
ofthebulkandabiasedsampleresults.
Causesofbiasinsampling:
Biasduetophysicalcharacteristics:Longerfibersalwayshavea
greaterchanceofbeingselected.
Positionrelativetotheperson:Labassistantmaypickbobbins
fromtoplayerofacaseofyarn(whethertosavehimselfthe
taskofdiggingdownintothecaseorbecausehehasnever
beentoldotherwise,wedonotknow),butthebobbinchosen
willbebiasedduetotheirposition.
Subconsciousbias:Personselectingconeswillpickthebest
lookingonesfreefromridges,cubwebbedends,etc.,without
thinkingaboutit.

12. Zoning techniques
Usedforfiberbaleswherethepropertiesmayvaryconsiderablyfromplace
toplace.(forrawcottonorwool)
Steps in zoning technique
Fiber sampling from bulk

13. Preparetuftsfromthebulk.
Dividethissampleintofourquarters.
Take16smalltuftsatrandomfromeachquarter,thesize
approximately20mg.
Eachtuftshallbehalvedfourtimes,discardedalternatelywith
rightandlefthandsandturningthetuftthrougharightangle
betweensuccessivehalving's.16'wisps'arethusproducedfrom
eachquartersample.
Combineeachsetofwispsintoatuft.
Mixeachtuftinturnbydoublinganddrawingbetweenthe
fingers.
Divideeachtuftintofourparts.
Obtainfournewtuftsbycombiningapartofeachofformer
tufts.
Mixeachnewtuftagainbydoublinganddrawing.
Takeaquaterfromeachtufttomakethefinalsample.

14. Zoning

15. Core sampling
Coresamplingisatechniquethatisusedforassessingtheproportionof
grease,vegetablematterandmoistureinsamplestakenfromunopened
balesofrawwool.Atubewithasharpenedtipisforcedintothebaleanda
coreofwooliswithdrawn.

16. Fiber sampling from combed slivers,
rovings and yarn
•Thesamplewegetwillbelengthextentbiased.Thisisbecauseunlessspecial
precautionsaretaken,thelongerfibersinthematerialbeingsampledaremorelikely
tobeselectedbythesamplingprocedures,leadingtoalength-biasedsample.
•Itisthefiberextent/location/ratherthanthefiberlengthassuchwhichdetermines
thelikelihoodofselection.

17. Approachestosolvetheproblem:
•Preparingnumericalsample:Inanumericalsamplethepercentageby
numberoffibersineachlengthgroupshouldbethesameinthesampleasit
isinthebulk.
•PreparingLengthbiasedsample:thepercentageoffibersinany
lengthgroupisproportionaltotheproductofthelengthandthe
percentageoffibersofthatlength.
•IfthelinesAandBrepresentplanesthroughthesliverthenthe
chanceofafibercrossingtheselinesisproportionaltoitslength.
If,therefore,thefiberscrossingthisareaareselectedinsome
waythenthelongerfiberswillbepreferentiallyselected..

18. •Thistypeofsampleisalsoknownasatuftsampleandasimilarmethodis
usedtopreparecottonfibersforlengthmeasurementbythefibrograph.
•Thiscanbeachievedbygrippingthesamplealonganarrowlineofcontact
andthencombingawayanyloosefibersfromeithersideofthegrips,so
leavingasample.
In sample the ratio of proportion of 10mm,
20mm, and 30mm would be 1:2:3.

19. Takeoutfiber(2mmateachstage)anddiscarduntiladistance
equaltothatofthelongestfiberinthesliverhasremoved.
Afterthateachdrawwillbeofnumericalsamples.
RANDOM DRAW METHOD

20. Cut all the projected fibers and discarded. The glass plate is then
moved back few mm, exposing more fibers with “natural length”
without cut. In each case projected fiber ends must be removed.
CUT SQUARE METHOD

21. 2. Atmospheric Condition For Testing
Atmospheric Condition
For Testing
2

22. 2. Atmospheric Condition For Testing
oThepropertiesoftextilefibersareinmanycasesstrongly
affectedbytheatmosphericmoisturecontent.
oManyfibers,particularlythenaturalones,arehygroscopicin
thattheyareabletoabsorbwatervaporfromamoist
atmosphere.
oIfsufficienttimeisallowed,equilibriumwillbereached.

23. oTheamountofmoisturethatsuchfiberscontain
stronglyaffectsmanyoftheirmostimportant
physicalproperties.Theconsequenceofthisis
thatthemoisturecontentofalltextileproducts
hastobetakenintoaccountwhenthese
propertiesarebeingmeasured
oEffects:
oDimensional
oMechanical
oElectrical
oothers

25. •woolandviscose,losestrengthwhentheyabsorbwater
whilecotton,flax,hempandjute,increaseinstrength.
•Fibersthatabsorbwaterfrom30to90%,the
approximaterelationb/nelectricalresistanceand
moisturecontentis,
RM
n
= k
where R = resistance,
M = moisture content (%),
and n and k are constants.
when fibers absorb moisture dimensionally they will get
swell which will increase their mass.

26. Isaratio,expressedinpercent,oftheamountofatmospheric
moisturepresentrelativetotheamountthatwouldbepresentif
theairweresaturated.
Sincethelatteramountisdependentontemperature,relative
humidityisafunctionofbothmoisturecontentand
temperature.
Relative humidity

27. ✓Standard asthenosphere for textile laboratories
✓Becauseoftheimportantchangesthatoccurintextile
propertiesasthemoisturecontentchanges,itis
necessarytospecifytheatmosphericconditionsinwhich
anytestingiscarriedout.
✓Thereforeastandardatmospherehasbeenagreedfor
testingpurposesandisdefinedasarelativehumidityof
65%+/-2andatemperatureof2O
0
C+/-2.
✓Intropicalregionsatemperatureof27±2
0
Cmaybe
used.

28. Control of testing room atmosphere
✓Testinglaboratoriesrequiretheatmospheretobemaintainedat
65±2%RHand20±2Cinordertocarryoutaccuratephysical
testingoftextiles.
✓Thetemperatureiscontrolledintheusualwaywithaheaterand
thermostat,butrefrigerationisnecessarytolowerthe
temperaturewhentheexternaltemperatureishigherthan2OC
asisusuallythecaseinsummer.
✓Therelativehumidityiscontrolledbyahygrometerwhich
operateseitherahumidificationoradryingplantdependingon
whetherthehumidityisaboveorbelowtherequiredlevel.

29. Theamountofmoistureinafibersamplecanbeexpressedaseitherregain
ormoisturecontent.Regainistheweightofwaterinamaterialexpressedas
apercentageoftheovendryweight
WATERCONTENTORMOISTURECONTENTisthequantityofwater
containedinamaterial,
MOISTUREREGAIN:isdefinedasthepercentageofwaterpresentina
textilematerialofovendryweight.
whereDisthedryweightandWisthe
weightofabsorbedwater.
Regain and moisture content
Moisture content is the weight of water expressed as a percentage of the total weight

30. RELATION SHIP B/N MR andMC

35. Itcanbemeasuredindifferent
ways,themostwidelyused
beingovendrier.
1.Byovendrymethod
(Direct)
Aconditioningovenisused
whichisameshcontainer
suspendedinsidetheovenfrom
onepanofbalance,the
mechanismofwhichisoutside
theoven.
Thedrymassisobtainedby
dryingthesampleata
temperatureof105±20C.
Constantmassisachievedby
dryingandweighingrepeatedly
untilsuccessiveweighingdiffer
bylessthan0.05%.
Measurement of moisture

36. Acontinualflowofairatthecorrectrelativehumidityispassed
throughtheovenwhichismaintainedat105
o
C.
Themainadvantageofusingaconditioningovenforcarryingour
regaindeterminationsisthatalltheweighingiscarriedoutinside
theoven.
Themethodisbasedontheassumptionthattheairdrawnintothe
ovenisatthestandardatmosphericcondition.Ifthisisnotthecase
thecorrectionhastobemade
aPercentagecorrection=0.5(1-6.48x10
4
xExR)%
WhereR=relativehumidity%/100,andE=Saturationvapour
pressureinpascalsatthetemperatureoftheairentertheoven
(takenfromatableofvalues)

37. •TheaccentonspeedoftestingisillustratedbytheTownsonand
MercerinstrumentwhichemploysanIRlamptodryoutthesample.
•A5gramsampleisused,aconstantoriginalweightwhichenables
thebalanceincorporatedintheinstrumenttobegraduatedin
percentageofmoistureinsteadofgrams.Timesquotedforthetest
include3minforviscosefiberand8minforcotton.
•Theaccuracyclaimedisthattheresultsarereproducibletowithin
0.2percentwithunskilledoperators.
2.IR drying method (Direct)

38. 3.Capacitance/Resistancemethod(Indirect)
➢Themeasurementofresistanceorcapacitancechanges
canbeusedtogiveanindirectmethodofregain
determination.
➢Twoelectrodesarepushedintoapackageofyarnandthe
resistancebetweentheelectrodesismeasuredbysuitable
electronics,theanswerbeingdisplayedonascalewhichis
directlycalibratedinregainvalues.
Differentelectrodesetsareusedfordifferentpackages,for
examplelongthickprongsforbalesandshortneedlelike
probesforyarnpackages.

39. Theinstrumenthastobecalibratedforthetypeofprobe,the
typeoffiberandtheexpectedregainrange.
Advantages:speedandeaseofreading,thefactthattheycan
calibratedirectlyinregainunitsanditcanbemadeportable.
Thedisadvantagesofelectricalmethodsaretheneedto
recalibratethemastheyareindirectmethods,thevariationsin
readingsduetopackagingdensity,presenceofdyes,antistatic
agentsandalsovariationsinfiberquality.

40. SpectroscopicMoistureAnalysis
Spectroscopicmethodsofdeterminingmoisture
content include infrared(surface
moisture),microwave(totalmoisture)
andnuclearmagneticresonance(NMR)
spectroscopy.Theseindirectmeasurement
methodscanbequitecomplexand/ortime
consumingbecausetheyrequiremultiple
samplesforcalibration.Forthatreasontheyare
notwidelyusedformoisturecontentquality
controlchecksalongpackaginglines.

41. Time:A sample takes a certain amount of time to reach
equilibrium. This rate of conditioning depends on size and
from of material, the material type.
Relative Humidity: Higher the RH Higher will be Regain.
Temperature:No direct impact, but at high temperature
the atmosphere can hold more water.
The previous history of sample:Bleached or scoured
cotton will absorb more moisture than untreated material.
Factors Affecting the Regain of
Textile Material:

42. Fiber length and
Fineness
3

43. Themostfibercharacteristicsislengthstrengthandfineness.
Firstly,longerfibers
Easiertoprocess.
Moreevenyarnscanbeproduced
ahigherstrengthyarn
Alternativelyayarnofthesamestrengthcanbeproducedbut
withalowerleveloftwist,thusgivingasofteryarn.
Thelengthofnaturalfibersvariesgreatlywhilemanmadefiber
lengthcanbecontrolled;forblendingpurposeitisdependent
onthelengthofnaturalfibers.
Thelengthandfinenessaresometimesrelatedinnaturalfibers
whereasforman-madefibers,lengthandfinenesscanbe
controlledseparately.
Forwool,longerfibersarecoarserwhilelongcottonfibersare
finer.
Fiber Length

44. TheaveragelengthofaspinnablefiberiscalledStaple
Length.Staplelengthisalsomostimportantfiber
characteristics.
It influences:
1.Spinning limit.
2.Yarn evenness.
3.Handle of the product.
4.Luster of the product.
5.Yarn hairiness.
6.Productivity.
TheStaple Lengthgroupings are currently used in the trade
staple:
1.Short Staple: 1inch or less.
2.Medium staple: 1.03 to 1.125 inch.
3.Long staple: 1.16 to 1.38 inch.
4.Extra long staple: 1.09 and above.
1.Staple length

45. 2. Mean length
Inthecaseofnaturalfibersthedefinitionofmeanlength
isnotasstraightforwardasitmightbe.Thisisbecause
naturalfibersbesidesvaryinginlengthalsovaryin
diameteratthesametime.
Ifthefibersallhadthesamecross-sectionthenthere
wouldbenodifficultyincalculatingthemeanfiber
length.
However,ifthefibershavedifferentdiametersthenthe
thickerfiberswillhaveagreatermasssothatthereisa
casefortakingthemassintoaccountwhencalculating
themeanlength.Thereareinfactthreepossiblewaysof
derivingthemeanlength:.

46. 1.Meanlengthbasedonnumberoffibers
(unbiasedmeanlength)L.
2.Mean length based on fiber cross-section
(cross-section biased mean length) Hauteur H.
3.Mean length based on fiber mass (mass-
biased mean length) BarbeB

47. Itdoesn’tconsidertheeffectoffibercrosssectionandmass.Simplyan
arithmeticmeanandisunbiasedmeanlength.
Toseetheeffectofdifferentfiberdiametersonthemeanlengthconsiderthree
differentfiberseachwithadifferentcross-sectionalareaaandadifferentlengthl
asshowninFig.above.So,themassW:
ρ=fiberdensity
In the calculation of mean length each fiber is given an equal weighting no
matter how large the diameter of the fiber is.
1. Mean length based on number of fibers

48. 2. Cross-section biased mean length H (Hauteur)
Inthiscalculationofmeanlengtheachfiberisweightedaccordingtoits
cross-section,sothatifafiberhasacross-sectiona1,a2,a3sothecalculation
ofthemean:
3. Mass-biased mean length B (Barbe)
TheBarbeisobtainedwhenthefiberlengthgroupsfromacombsorterare
eachweighedandtheaveragelengthcalculatedfromthedata.The
Hauteurcanbeobtainedfromthedatabydividingthemassofeachlength
groupbyitslengthandexpressingtheresultasapercentage:
w=alp,Thereforeifdensitypisassumedconstantthen:

49. The methods used to measure fiber length fall into
two main types:
The direct measurement of single fibers mainly for research
purposes and
MethodsthatinvolvepreparingAtuftorbundleoffibers
arrangedparalleltooneanother.
Methods of Fiber length
measurement

50. A. Hand stapling method: (By trained
classers):
Selectingasampleandpreparingthefibresbyhanddoubling
anddrawingtogiveafairlywellstraightenedtuftofabout½
inchwide.
Thisislaidonflatblackbackgroundandthestaplelengthis
measured.
Theshorterfibreswilllieinbodyofthetuftandextremeends
(tips)willnotbethelimitsusedformeasurementofstaple
length.
Theclasserchoosesthelengthwheretherearereasonablywell
definededges.
Subjectiveinnature,sodifferenceinresultsbetweenclassers.
Measurement of Individual Fibre
Length:(Cotton fibre length)

51. (B)Comb Sorter Method

52. In the diagram
OQ = 1/2 OA
OK = 1/4 OP
KS = 1/2 KK’
OL = 1/4 OR
Short fibre percentage = (RB/OB) ×100%
LL’ = Effective length (because many m/c settings are
related with this length)
LL’-MM’ = NL’=Inter-quartile range
Dispersion% = NL’/LL’

53. Span Length
Spanlengthisthedistanceexceededbyastated
percentageoffibersfromarandomcatchpointin
draftingzone.2.5%and50%spanlengtharethemost
commonlyusedbyindustry.
2.5%SpanLengthand50%SpanLength:
x%Spanlengthisthedistancespannedbyx%offibers
inthespecimenbeingtestedwhenthefibersare
parallelizedandrandomlydistributedandwherethe
initialstartingpointofthescanninginthetestis
considered100%.Thislengthismeasuredusing“Digital
Fibrograph‘.

54. Uniformity Ratio
The ratio between 50% span length and 2.5% span length
is called uniformity ratio, express as apercentage.

55. Uniformity Index
UI Description
<77 VL
77-80 L
81-84 M
85-87 H
>87 VH

56. Upper Half mean length(UHML)
The 50% point of fibers and extrapolating to the
lengths axis indicates the Upper Half Mean length .

57. Fibersinthedraftingzonethatarenotclampedby
eitherofthepairsofrollersofdraftingzoneare
referredtoasfloatingfiberindex.Itisexpressedas
apercentageandcalculatedbythefollowing
equation.
Floating Fiber Index (FFI):

58. SFC can be calculated from the output of
thefibrogram
 SFC% = 50.01−( 0.766×2.5%SL) − (81.48×50%SL)
Short Fiber Content (SFC)
amount of fiber shorter than 0.5in.
SFC Description
<6 VL
6-9 L
10-13 M
14-17 H
>17 VH

59. Opticalmethodofmeasuringthedensityalongthe
lengthofatuftofparallelfibres.Samplesareprepared
by“fibrosampler
C. Photoelectric method (Fibro
graph):

60. The point where it is caught is at random along its
length.
Distance traveled from base line
Floating fibre (%) = [2.5%SL / L –0.975} ×100
U.R. = (50%SL / 2.5% SL) ×100[apprx. 40-50%
for normal cotton]
Where L = avg. length of fibre

61. Anattempttoautomatetheprocessof
singlefibermeasurementandisintended
mainlyformeasuringwoolfibers.
Rotatingshaftwithaspiralgroovemachined
init.Oneendofthefibertobemeasuredis
grippedbyapairoftweezerswhosepointis
thenplacedinthemovingspiral.Thishasthe
effectofmovingthetweezerstotheright
andsosteadilydrawingthefiberthroughthe
pressureplate.Thisensuresthatthefiberis
extendedunderastandardtension.
D.WIRA fiber length machine

62. Afinewirerestsonthefiberandisarrangedsothatwhen
thefarendofthefiberpassesunderthewireitallowsitto
dropintoasmallcupofmercuryandthuscompletean
electricalcircuit.Thiscausestheshafttostopmoving,so
haltingthetweezers;atthispointthetweezersarethen
raisedtoliftthecounterimmediatelyabovewhereithas
stopped.Finallymeasurementwillbetakenfromthe
counter.

63. Tuftmethodsareoftenusedforroutinefiberlengthtestingasthey
aremorerapidthanthedirectmethods.Thepreliminarypreparation
isdirectedtowardsproducingabundleofparallelfibers.
Dangeroffiberbreakage
Clamping.
Combiningtoremovelooseungrippedfibres.
Theprotrudingtuftsarecutfromedgeoftheclampandweighed.
Theclampsthenopenedandfibresinsideclampsareweighed
separately.
whereWis the width of clamp
E. Tuft methods

65. Forquickermeasurementoflength(staplelength).
Objectivemeasuringtechniqueofearlierstaplelength
measuringmethod.(Classerjudgesbyeye).
F. Shirley photoelectric stapler

66. Fringesoffibrearepreparedby
handandcarefullyplacedover
blackvelvetpad
Thephotoelectricstaplerdetects
thedistancebetweenwherethe
densitygradientaremaximum
(oneitherside).
Twophotoelectriccellsconnected
oppositiontoeachother
Dependingonlightintensity,the
opposedcellspassacurrent,
whichisproportionaltothe
differenceintheintensity.
Variationincurrentisshownin
sensitivegalvanometer.
Asthefringeisadvancedinside
theinstrument,twomaximum
densitygradientpointwillbethere
andthisdistanceis“staplelength”
(max.deflectionofgalvanometerin
oppositedirection)

67. FINENESS
➢Finenessdescribesthemeasurementofcross-
sectionalareaoffibersoryarns.
➢Thefinerthefiber,thefineristheyarnthatcanbe
spunfromit.
➢Thespinninglimit,thatisthepointatwhichthefibers
cannolongerbetwistedintoayarn,isreachedearlier
withacoarserfiber.
➢Coarserfiberismorerigidandstiff,difficulttotwist
duringspinning.
➢Thestiffnessofthefibersaffectsthestiffnessofthefabric
madefromitandhencethewayitdrapesandhowsoftitfeels.

68. WhyFiberFinenessissoimportant:
1.ItaffectsStiffnessoftheFabric
➢Thefinenessdetermineshowmanyfibresare
presentinthecross-sectionofayarnofgiven
thickness.Additionalfibresinthecross-section
providenotonlyadditionalstrength,butalsoa
betterdistributionintheyarn.
Asthefiberfinenessincreases,resistanceto
bendingdecreases.
Itmeansthefabricmadefromyarnoffinerfiber
islessstiffinfeel.Italsodrapesbetter.

69. 2.ItaffectsTorsionalRigidityoftheYarn
➢Torsionalrigiditymeansabilitytotwist.
Asfiberfinenessincreases,torsionalrigidityoftheyarn
reducesproportionally.
Thusfiberscanbetwistedeasilyduringspinningoperation.
➢Alsotherewillbelesssnarlingandkinkformationinthe
yarnwhenthefinefibersareused.
3.ReflectionofLight
Finerfibersalsodeterminethelusterofthefabric.
Becausetherearesomanynumberoffibersperunitarea
thattheyproduceasoftsheen.
Alsotheapparentdepthoftheshadewillbelighterincase
offabricsmadewithfinerfibersthanincaseofcoarser
fibers.

70. 4.AbsorptionofDyes
Theamountofdyeabsorbeddependsupontheamountof
surfaceareaaccessiblefordyeoutofagivenvolumeof
fibers.Thusafinerfiberleadstoquickerexhaustionof
dyesthancoarserfibres.
5.EaseinSpinningProcess
Afinerfiberleadstomorefibrecohesionbecausethe
numbersofsurfacesaremoresocohesionduetofriction
ishigher.
Alsofinerfibersleadtolessamountoftwistbecauseof
thesameincreasedforceoffriction.
Thismeansyarnscanbespunfinerwiththesameamount
oftwistascomparedtocoarserfibers,
..

71. 6.UniformityofYarnandHenceUniformityin
theFabric
Uniformityofyarnisdirectlyproportionalto
thenumberoffibresintheyarncrosssection.
Hencefinerthefiber,themoreuniformisthe
yarn.Whentheyarnisuniformitleadstoother
desirablepropertiessuchasbettertensile
strength,extensibilityandluster.
Italsoleadstofewerbreakagesinspinningand
weaving

72. ➢Finenessdescribesthemeasurementofcross-sectionalareaoffibersor
yarns.
➢Itdifficulttodefineameasureoffinenessasameasureofitsdiameter
orx-sectionduetoanumberofreasons:
1.Thecross-sectionofmanytypesoffibersisnotcircular
Woolhasanapproximatelycircularcross-sectionbutsilkhasatriangular
cross-sectionandcottonislikeaflattenedtube
2.Thecross-sectionsofthefibersmaynotbeuniformalongthefiber
length.Thisisoftenthecasewithnaturalfibers.
thecross-sectionalshapeofthefibersmaynotbeuniformfromfiberto
fiber.
Fineness measurement

73. Foragivenfiber(thatisofafixeddensity)itsmassis
proportionaltoitscross-sectionalarea:
m=a*l*p
Massofafiber=cross-sectionalareaXlengthXdensity
Thereforeforaknownlengthoffiberitsmasswillbe
directlyrelatedtoitscross-sectionalarea.
Themassofagivenlengthoffiberisusedasameasure
ofitsfineness.
TheprimaryunitisTex
tex(g/lOOOm),
So, there should be alternative measurement systems which indirectly can
measure the diameter or x-section of fibers.
1. Gravimetric or dimensional measurements

74. Decitex=massingramsof10,000
metersoffiber
Millitex=massinmilligramsof
1000metersoffiber
Denier=massingramsof9000
metresoffiber
Forfiberswithacircularcross-section
suchaswoolthemassperlengthcanbe
convertedintoanequivalentfiber
diametersometimesknownasd(grav.)
usingthefollowingequation:

75. The projection
microscopeisthe
standardmethodfor
measuringwoolfiber
diameter,andallother
methodshavetobe
checkedforaccuracy
againstit.
Themethodisalso
applicabletoanyother
fiberswithacircular
cross-section.
2. Fiber fineness by projection microscope

76. Itinvolvespreparinga
microscopeslideofshort
lengthsoffiberwhichis
thenviewedusinga
microscopethatprojects
animageofthefibersonto
ahorizontalscreenfor
easeofmeasurement.
Techniquesarefollowed
thatavoidbiasandensure
atrulyrandomsample.

77. Thisisanindirectmethod
Theairflowatagivenpressuredifferencethrougha
uniformlydistributedmassoffibersisdeterminedbythe
totalsurfaceareaofthefibers.
3.Fiber fineness by the airflow method
Thesurfaceareaofafibre(lengthXcircumference)is
proportionaltoitsdiameterbutforagivenweightof
samplethenumberoffibresincreaseswiththefibre
finenesssothatthespecificsurfacearea(areaperunit
weight)isinverselyproportionaltofibrediameter;

78. Thespecificsurfaceareawhichdeterminestheflowof
airthroughacottonplug,isdependentnotonlyupon
thelineardensityofthefibresinthesamplebutalso
upontheirmaturity.
Hencethemicronairereadingshavetobetreatedwith
cautionparticularlywhentestingsamplesvarying
widelyinmaturity.
Suitableformillpracticeduetoitsspeedof
measurement
Foraconstantmassoffibre(i.e.Theactualvolume)
theairflowisinverselyproportionaltothespecific
surfacearea

79. Micronaire(MIC) is a measure of
the air permeability of compressed
cotton fibers. It is often used as an
indication of fiber fineness and
maturity.
Micronaire Description
<3 Very fine
3.1-3.6 Fine
3.6-4.7 Medium
4.8-5.4 Course
>5.5 Very Course

80. 4.Vibration method
•Usedforindividualfibre(onefibreatatime)
•Anindirectmethodofestimatingthemass/unitlengthof
fibre,basedonthetheoryofvibratingstrings.
•.Thenaturalfundamentalfrequency(f)ofvibrationofa
stretchedfiberisrelatedbothtoitslineardensityandtothe
tensionusedtokeepittight:

81. ➢oneendofaweightedfiberis
clampedandtheloweredgeofthe
fiberpassesoveraknifeedge,thus
providingafixedlengthoffiber
under tension.
➢Theleveloftensionusedisinthe
rangefrom0.3to0.5cN/tex
usuallyappliedbyhanginga
weightedclipontheendofthefiber.
➢Thefiberiscausedtovibrateeither
byvibratingthetopclamporby
usingacoustictransducersandthe
amplitudeofthevibrationmeasured
overarangeoffrequencies.

82. F=(1/2l)×√(T/M)
M= Tx(1/2lf)
2
Where,
F = natural fundamental frequency of
vibration (c/s)
T= tension
M= mass per unit length (gm/cm)
L= free length
l = wave length

83. Itisanon-microscopically
methodofmeasuringfibre
diameterandoperatesbylight
scattering.Thefibre(cutinto
snippets1.8mmlong)and
suspendedinIsopropanol(to
giveaslurry)arecausedto
intersectacircularbeamof
lightinaplaneatrightangles
tothedirectionofthebeam
(notgreaterthan200
micrometerdia).
Theintensityofscattered
lightisproportionaltothe
projectedareaoffibre,i.e.
diameter
5. Light scattering method (OFDA: OpticalFibre
Diameter Analyzer):

84. Onlyfibresthatcompletely
crossthebeamarerecorded,
sothatthescatteredlight
pulseisthenproportionalto
thefibrediameter.
Theflowrateand
concentrationoftheslurry
aresuchthatfibreintersect
thebeamoneatatime.The
snippetswhichdonotfully
intersectthebeamare
rejected.
TheCapableofmeasuring
50fibrespersecond.The
beamdiameterismaximum
200micrometertoreduce
theeffectofanycurvature
duetofibrecrimp

86. MATURITY TESTING

87. Fiber Maturity
➢Cottonfiberconsistsofcellwallandlumen.
Thematurityindexdependsuponthethickness
ofthecellwall.
➢Unripefibershaveneitheradequatestrength
noradequatelongitudinalthickness.Theylead
tolossofyarnstrength,neppiness,high
proportionofshortfibers,varyingdyeability,
processingdifficultiesmainlyatthecard.

88. Tomeasurematuritysomemethodofmeasurementis
required.Thedegreeofcellwallthickeningmaybeexpressed
astheratiooftheactualcross-sectionalareaofthewalltothe
areaofthecirclewithsameperimeter(seefigure)
Measurement of fiber maturity:

90. Acompletelysolidfiberwouldhaveadegreeofthickeningof1.
Maturefibershaveanaveragevalueofaround0.6andimmature
fibershaveanaveragevalueofbetween0.2and0.3.


91. 1.Measurements of cotton maturity
by caustic soda
Itismostcommonlyused
Athintuftoffibreisdrawnbymeansoftweezerfromasliver
helpinacombsorter.
Thetuftislaidonamicrroscopeandacoverslipputoverthe
middleofthetuft.
Therearetwostepinvolvedinthismethod
Treatmentwith18%cousticsoda
Thefibreonthemicroscopeslidearethensaturatedwithsmall
amountof18%cousticsodasolutionwhichisswellingthem.
Examinationunderamicroscopetocountthemature,halfmature
andimmaturefibre.
Theslideisthenplacedonstageofmicroscopeandexamined.

92. 1.Normalfibersarethosethat
afterswellingappearassolid
rodsandshownocontinuous
lumen.
2.Deadfibersarethosethatafter
swellinghaveacontinuous
lumenandthewallthicknessisa
fifthorlessthantheribbon
width.
3.Thin-walledfibersarethose
thatarenotclassedasnormalor
dead,beingofintermediate
appearanceandthickening

93. Around100fibersfromBaersortercombsare
spreadacrosstheglassslideandtreatedwith
18%causticsodasolutionviewedunder
microscopeandexamined:
MATURITY CO-EFFICIENT

94. 2. Measurements of cotton maturity by
Polarized Light

95. Maturity ratio

96. Category Rangeofmaturity
coefficient
Veryimmature
Immature
Averagematurity
Goodmaturity
Veryhighmaturity
Below0.60
0.60to0.70
0.71to0.80
0.81to0.90
Above0.90

97. 3. Mature and immature fibers differ in their behavior
towards various dyes. Certain dyes are preferentially taken
up by the mature fibers while some dyes are preferentially
absorbed by the immature fibers.
•ItisdevelopedintheUnitedStatesofAmericafor
estimatingthematurityofcotton.Inthistechnique,the
sampleisdyedinabathcontainingamixtureoftwo
dyes,namelyDiphenylFastRed5BLandChlorantine
FastGreenBLL.
•Thematurefiberstakeupthereddyepreferentially,
whilethethinwalledimmaturefiberstakeupthegreen
dye.
3. Measurements of cotton maturity by
dyeing methods:

98. TRASH CONTENT
5

99. Inadditiontouseablefibres,cottonstock
containsforeignmatterofvariouskinds
Thisforeignmaterialcanleadtoextreme
disturbancesduringprocessing.
Trashaffectsyarnandfabricquality.Cottons
withtwodifferenttrashcontentsshouldnotbe
mixedtogether,asitwillleadtoprocessing
difficulties.
Thereforeitisamusttoknowtheamountoftrash
andthetypeoftrashbeforedecidingthemixing.

100. Measurements of trash
1.Shirley Trash Analyzer
100g.ofcottonsample‘S’
tobeanalysedisweighed
accuratelyandispassed
throughtheTrashAnalyser
givingL
1g.oflintandT
1g.of
trash.ThetrashT
1is
collectedand again
processedgivingL
2g.oflint
andT
2g.oftrash.Thelint
portionsL
1andL
2are
weighedtogetherandgive
thetotallintcontentinthe
sample.

102. IftheTrashT
2isstill
foundtocontainasizable
amountoflint,itispassed
onceagainthroughthe
AnalyzergivingL
3g.oflint
andT
3g.oftrash.Thenlint
contentL=L
1+L
2+L
3
andTrashT=T
3.
Ingeneral,twosuch100g.
samplesareanalyzedand
theaveragecalculated.It
isessentialthatthesample
processedmustbefairly
representativeofthebulk
sample.

103. 2.optical –electronic trash analyzer
OnedrawbackofShirleyAnalyzermethodisthatit
cannotprovideinformationrelatingtothenumberor
sizeofnon-lintparticles.Thishaspromptedthe
developmentofvariousoptical–electronic
techniquesformeasuringthenumberandphysical
featuresofnon-lintparticlesfoundonthesurfaceof
rawcottonsamples.

104. .
aninstrumentwhichemploysatelevisioncamera
toviewthesampletobeanalyzedandaspecializedcomputer-
basedsignalanalysissystemtoanalyzethesignal
fromthecamera.Thesignalanalyzercandetermineand
displayinformationconcerningthenumber,sizedistribution,
lengthandareaofparticlesviewedbythecamera.The
workinggroupon"DustandTrash"attheInternationalcotton
conferenceinBremen(1990)recommendedShirleyAnalyzer
MarkII,MicrodustandTrashMonitor(MTM)fromUster
Technologies,USAandITVDustandTrashTesterfrom
Hollingworthasstandardinstruments.

105. Measurementoftrash,providingameasureofthesample
surfacearea(%AREA)coveredbytrashandthenumber
(COUNT)ofparticles.
ThetwoHVIsystemmeasuretrashinasimilarway,
althoughusingdifferentpixelspacing.Avideocamera
opticallyscansamplecompressedagainstaviewingwindow
abovethecamera.
IntheMotionControlHVIsystemstheviewingareais
dividedintoamatrixof59500rasterpoints(pixels)or248x
240rasterlines.Darktrashparticles(i.e.thosewhosecolor
valueis30%darkerthanthelightcottoncolorofthe
environment)arecounted.
TheAreaiscalculatedbytherelationship,
WhereNxisthenumberofpixelsdarkenedbytrash.The
COUNTisgivenbytherelationship,

106. Thecleaningefficiencyhelpstoevaluatetheperformance
ofamachine.Ifitfallsbelowacertainlevelthemachine
needstobechecked.Theremovaloftrashparticlessuchas
seed&leafparticles,stalks,sandanddustfromcottonis
quantitativelyexpressedascleaningefficiencywhichcan
beestimatedasfollow.
About200gmofsampleistakenfromthefeed&delivery
ofamachinelikeBlowroom,CardorBeaters.These
samplesareanalyzedfortrashcontent.Thisisdoneby
processinga100gmofsamplethroughaTrashAnalyzer
andcollectingthetrashobtained&weighingitaccurately.
Twosamplesmustbeanalyzedandaveragetrashcontentis
calculated.
The Cleaning Efficiency of a Machine:

110. Fiber quality measurements using
High volume instruments(HVI) ,
AFIS

111. HIGH VOLUME INSTRUMENT
TESTING (HVI)
ADVANTAGES:
Following are the advantages of HVI testing:
the results are practically independent of the
operator
the results are based on large volume
samples, and are therefore more significant
the respective fiber data are immediately
available
the data are clearly arranged in summarized
reports
they make possible the best utilization of raw
material data

112. Problemsasaresultoffibermaterialcanbepredicted,and
correctivemeasuresinstitutedbeforesuchproblemscan
occurcottonclassificationdoesnotonlymeanhowfineorclean,or
howlongafibreis,butratherwhetheritmeetstherequirementsof
thefinishedproduct.
Tobemoreprecise,thefibrecharacteristicsmustbeclassified
accordingtoacertainsequenceofimportancewithrespecttothe
endproductandthespinningprocess.
TheabilitytoobtaincompleteinformationwithsingleoperatorHVI
systemsfurtherunderscorestheeconomicandusefulnatureofHVI
testing.
TwoinstrumentcompanieslocatedintheusmanufacturetheseHVI
systems.Boththesystemsincludeinstrumentstomeasure
micronaire,length,lengthuniformity,strength,color,trash,
maturity,sugarcontent,etc.

113. Asystemmayinclude
anycombinationofthe
followingmeasuring
modules:
Length/Strength
Module
MicronaireModule
Color/TrashModule

114. Fiber length is measured by optically by the LEDs when the
fiber Beard entered the measuring zone

115. FLU Description
<77 Very low
77-80 Low
81-84 Medium
85-87 High
>87 Very high

116. The amounts of fiber in the cotton sample shorter
than 0.5 inch or 12.7 mm
SFI
SFI% Description
<6 Very low
6-9 Low
10-13 Medium
14-17 High
>18 Very high

117. HVIusesthe“Constantrateofelongation”principlewhile
testingthefibresample.Theavailableconventional
methodsofstrengthmeasurementareslowandarenot
compatibletobeusedwiththeHVI.Themainhindering
factoristhemeasurementofweightofthetestspecimen,
whichisnecessarytoestimatethetenacityofthesample.
Expressionofthebreakingstrengthintermsoftenacityis
importanttomakeeasycomparisonbetweenspecimensof
varyingfineness.
Principle of Measurement

118. Strength(g/tex) Description
<21 Very low
22-24 Low
25-27 Medium
28-30 High
>31 Very high

119. Measurementofelasticbehavioroffibersinthe
bundle
Thedistancethefiberextendbeforetheybreakis
expressedaspercentofelongation
Bundle fiber elongation

121. Rd =The whiteness of the light that reflected by the
cotton fiber
+b=Yellowness of the light that is reflected by cotton
fiber

125. SCI=-414.67+2.9S-9.32M+49.17L+4.74UI+0.65Rd+0.36+b
SCI
it predicts the spinnablityof the fiber

126. Intextileindustryrawmaterialisthemostdominant
factorasitcontributes50-75%intotalmanufacturing
cost.
Inqualityconsciousscenario,qualityofrawmaterial
playsavitalrole.Butthequalityofrawmaterialis
decidedbymeasuringitsproperties.
Nowmeasurementthroughconventionaltechniquesis
verylaboriousandtimeconsuming.
Hencetheresearchersfocustheirattentiontowardsthe
inventionsofsuchinstrument,whichgivesaccurateand
quickresultandoneofthewonderfuldevelopmentis
AFIS-Advancedfibreinformationsystem.
ADVANCED FIBER INFORMATION
SYSTEM (AFIS)

127. BASICSPRINCIPLE:
Afibresampleisintroducedinto
thesystemandisprocessed
throughafibreindividualizer,
whichaeromechanically
separatesthesampleintothree
componentsconsistingof
cleanedfibre,microdust,and
trash.
Eachofthesecomponentsis
transportedinaseparate
pneumaticpathandanalyzed
electro-opticallyorbyother
means.
Thedataprocessingand
reportingarehandledbyan
industrializedPC.

128. usesuniquecleaningandseparating
techniquestopresentthefibres
pneumaticallytotheelectro-optical
sensor.
Aspecimenoffibreishandteasedintoa
sliver-likestrandandisinsertedintothe
feedassembly
Thefibresareopenedandcleanedusing
pinnedandperforatedcylinders,
Airflowintotheperforationsofthe
cylinderallowsforthoroughengagement
andefficientdustandtrashremoval.
Trashisreleasedafterthecardingaction
bythe"counterflow"separationslot.
Heavytrashparticlesareseparatedfrom
fibresandtransportedoutofthesystem,
whereas,thesmallerdustandfibresare
returnedtothecylinderaerodynamically
bytheairdrawnintotheslot,thusthe
term"counterflowslot".
Fibre individualizer:

129. Theelectro-optical(E-O)
sensorsconsistofthree
basicelementstapered
entranceandexitnozzles
(onVersion4lintsensor,a
singlepieceaccelerating
nozzle)beamforming
andcollectionoptics.
Electro-optical sensors:
Generally,rectangularwaveformsare
producedbythelightscatteredby
individualfibres.Nepsignalsare
muchgreaterinmagnitudeand
durationandgenerateacharacteristic
nep"spike".Trashparticlesproduce
smallerspikedwaveforms,whichare
distinguishablefromnepsin
magnitudeandduration.

130. 8
YARN COUNT

131. LinearDensity
Thethicknessordiameterofayarnisoneofitsmost
fundamentalproperties.However,itisnotpossibleto
measurediameterofayarninanymeaningfulway.
Asystemofdenotingthefinenessofayarnbyweighinga
knownlengthofithasevolved.Thisquantityisknownas
thelineardensityanditcanbemeasuredwithahigh
degreeofaaccuracyifasufficientlengthofyarnisused.
YARN COUNT

132. Therearetwosystemsoflineardensitydesignationin
use:DirectandIndirectsystem
1.Directsystem
Thedirectsystemofdenotinglineardensityisbasedon
measuringtheweightperunitlengthofayarn.
Itisfixedlengthsystem.
Finertheyarn,lowerthecountnumber.
Themainsystemsinuseare:
Tex-Weightingramsof1000meters
Denier-weightingramsof9000meters
Decitex-weightingramsof10000meters

134. 2.Indirectsystem
Thisisthetraditionalsystemofyarnlineardensity
measurement.
Theindirectsystemisbaseduponthelengthperunit
weightofayarnandisusuallyknownascount.
Itisbasedonthefixedweightsystem.
Finertheyarn,higherthecountnumber.
Themainsysteminuseare,
1.WorstedcountNew=numberofhanksall560yards
longin1poundCotton
2.CountNec(englishcountNe)=numberofhanksall840
yardslongin1poundMetric
3.CountNm=numberofkilometerlengthsperkilogram

136. Ne=(length in yd *)/(840yd*wt lb)
NeW= =(length in yd )/(560yd*wt lb
Nm=(length in meter)*wt in kg*100
I.e1, lb= 453g

138. Example 1: If the metric count is given 50 then
what will be the English cotton count?
Solution:
We know that, Ne=0.5905 X Nm
Where, English cotton count is expressed as Ne
And Metric count as Nm
So English count will be Ne=0.5905 X 50=30
Ans. 30 Ne

139. Measurementofyarnnumberorcount
Twobasicrequirementsforthedeterminationoftheyarn
numberare
A.Anaccuratevalueforthesamplelength
B.Anaccuratevalueforitsweight
.
1.Yarninpackageform
➢Whentheyarnisinpackageform,suchas
ringbobbinsorcones,itisusualtowinda
numberofskeinsbymeansofwrapreel.
Thisisasimplemachineconsistingofareel,
yarnpackagecreel,ayarnguidewith
traverse,alengthindicator,andawarning
bell.
Length measurement

140. Forcottonyarnsthereelhasagirth(circumferenceof
reel)of54inch,sothat80revolutionofthereelasskein
of120yard,oralea.(i.e1yd=36inch)and(1m=1.093yd)
Thesameleawillbeweighedaccuratelytocalculatethe
count.
2.Yarninshortlength(fromfabric)
Thedeterminationoftheyarncountofyarninfabricis
usuallymadeonacomparativelyshortsamplelength
becausethepieceoffabricavailable.
Afterconditioninginthetestingatmosphere,two
rectangularwarpwaystripand5weftwaystripsarecut
fromthecloth.
Inlength,thestripsshouldbeabout20inchandwide
enoughtoallowfiftythreadstoberemovedfromeach
strip.

141. Weight Measurement
1.Balances
Theanalyticalbalancesandanyotherspecialyarnbalances
usedinthedeterminationofcountmustbeaccurate,andit
isessentialthattheyarewellmaintained.
Theweightshouldbecapableofgivingaresulttoan
accuracyofnotlessthan1in500.
Theyarnremovedfromfabricwillhavecrimp.Soitis
measuredfirstandlengthshouldbecalculated.
C=(l-p)/p*100%
where,c=crimp,l=uncrimpedlengthandp=crimped
length.

142. Regain Measurement
Theproblemofaccountingforthepresenceofmoisturein
thesamplecanbetackledinseveralways,twoofwhich
areconsideredhere.
1)Determinetheovendryweightandmultiplyby

143. Example1.
Textiletechnologiesmeasurecottonyarnlengthandmassby
usingwrapreelswhichhaveacircumferenceof1.09361yard
with100revolutionandtheovendryweightis2.9525gram
byelectronicbalancerespectively.Calculatetheyarncountin
Texsystem?
Sol/n
1 yd=0.9144m
100*1.09361yd=109.361yd
109.361yd*0.9144m/yd=99.999 m
Tex= m(g) *1000
l(m)
=32 Tex

144. 2)Allowthesampletoconditioninthetesting
atmospherelongenoughtoreachequilibrium,and
thenweighinthesameatmosphere.
Amongthetwo,thefirstmethodwillgiveaccurate
resultthansecondmethod.

145. Whentestingspunpackages,
sixteenarerandomlychosen
andaleafromeachwrapped
onthereelatthecorrect
tension.
Theleasaretakentoconstant
weightinthedryingoven.
Theofficialregainisaddedto
theovendryweightsandthe
individualcountsare
recorded.Themeancountis
thencalculated.
Count testing methods
1.Wrap reel, drying oven, analytical balance

147. Itisusedtoreadcountsystem
directly
beambalanceisused,behind
whichisaseparaterodof
hexagonalsectionwithfiveofthe
facesletteredfromAtoEand
engravedwithacountscaleto
coveracertainrange.
FaceBofthescaleisturnedtothe
front,weightBisplacedintheleft-
handpan,andriderBputonthe
beam.
Thepositionoftheridertobe
adjusteduntilthebeamisbalanced.
Thisbalancecanbe,ofcourse,be
designedtosuitcountsystemsother
thanthatofcotton.
2.Wrap reel and a Knowles balance

148. directreadinginstrument
Agivenlengthismeasuredoutandsuspendedfrom
thehook,thecountisthenreaddirectlyfromthe
quadrantscale.
Theversatilityofthistypeofbalanceisimprovedby
engravingthescalewithmorethanoneseriesof
values.
Forexample,onescalemayreadfrom0.1to1.0to
givethehankofa4yardsampleofsliver.
Secondscalemayreadfrom0.1to0.6for20yard
samplesofroving.
Thirdscalemayreadfrom4sto80sfor840yard
samplesofyarn.
Thescalesjustmentionedareinthecottoncount
system,butotherquadrantbalancesareavailablefor
differentrangesanddifferentsystems.
3.Wrap reel and a quadrant balance

149. A).Normalcount
Itisdirectmeasurementsofsliver,
rovingandyarncountandgive
statisticaldataandgraphs.
B).Nominalcount;
Itisdirectmeasurementsofsliver,
rovingandyarncountandgive
statisticaldataandgraphswith
comparisonofthenominalor
theoreticalcountnumber..
4.Fast count analyzer

150. 1.basedonthelineardensityofthe
constituentyarnsand
2.basedontheresultantlineardensityof
thewholeyarn.
Inthefirstwaythetexvalueofthesingle
yarnsisfollowedbeamultiplicationsign
andthenthenumberofsingleyarns
whichgotomakeupthefoldedyarn,e.g.
Measuring folded yarns counts
Forexample,2/24scottoncountsystemimpliesayarn
madefromtwo24scountcottonyarnstwistedtogether;
1/12scottoncountmeansasingle12scountcottonyarn.
➢Inthetexsystemtherearetwopossiblewaysofreferring
tofoldedyarns:

151. 1.80Texx2:Thisindicatesayarnmadefromtwistingtogethertwo
80Texyarns.Thistypeofdesignationisgenerallyusedwithwoolen
yarns.
2.R74Tex/2:Thisindicatesayarnmadefromtwistingtwoyarns
togetherwhoseresultantcountis74Tex.Thistypeofdesignationis
generallyusedwithworstedyarns.

152. EX.3Aresultanttwoplyyarncountof16worstedhasone
componentyarnof36worsted.Whatisthecountoftheother
component?
EX.2A two ply yarn in Tex is composed of one thread 40 Tex,
one thread unknown count and has a resultant count of 100
Tex. What is the count of the other component yarn??

153. EX.4Athreeplyyarniscomposedofonethreadof56
worsted,onethreadof48worstedandonethreadof2/80
cotton.Whatisthecountofresultantyarn?

154. Countcalculationforplyyarnwithcontraction:
Normally,whentwosingleyarnsaretwistedtogetherone
shouldexpectsomecontractionorsomeincreasein
lengthdependingonthetwistingdirection.Acontraction
willresultinayarnslightlycoarserthantheestimated
value.Inordertocorrectforthisdifference,typically5%
to10%contractionorextensionshouldbeaccountedfor.

157. EX.5Supposetwoyarnsof24/1Nmaregoingtobe
pliedwith4%contraction.Finditsresultantcount
inmetricsystem.

158. EX.6Supposeyouareprovidedacottonyarnof1500kmof
2/24sfoundatcompletelydrycondition.Calculatethe
resultantcountinTexatstandardatmosphericconditionwith
7%contraction.

159. Let,
The yarn count be= N tex.
Tex= m(g) *1000
l(m)
And specific volume of yarn= 1.1
So, 1.1 cm^3 yarn has the weight of = 1 gm.
And yarn diameter= d cm.
Now,
N tex. Yarn has a length = 1000 m.
1 tex. Yarn has a length = (1000/N) m. = 10^5/N cm.
Relation ship between yarn count(Tex) and
yarn diameter

160. Again
Volume = Cross sectional area ×length
or, 1.1 = (πd²/4) ×( 10^5/N )
or, d² = (4×1.1 ×N) / (π×10^5)
or, d = √{4.4/ (π×10^5 ) ×√N
or, d = (0.375/ 100) ×√N
∴d = (0.375/ 100) ×√tex.
This is the relation between yarn diameter
(cm) and yarn count in Tex system.

161. Converting cm to inches and texto
cotton count:
Diameter in inch, d = (0.375/ 100) ×√tex.
Or, d = (0.375/ 100) ×√(590.5/Ne) ×
(1/2.54)[Tex = 590.5/Ne]
Or, d = (0.375 ×√590.5) / (100 ×√Ne ×
2.54)
Or, d = 3.6 / (100 ×√ Ne)
∴d = 1/ (28√Ne) inch.
This is the relation between diameter and
yarn count in cotton count (Ne) system.

162. YARN TWIST

163. Introduction:
Twist is the measure of the spiral turns given to yarn in
order to hold the fibres or threads together.
Twist is primarily instructed in to a staple yarn in order to
hold the constituent fibres together, thus giving strength
to the yarn.
Twist is necessary to give a yarn coherence and strength.
Real twist::
To insert a real twist into a length of yarn, one end of the yarn should
be rotated relative to the other end, Spun yarns usually have real twist.
False twist:
When inserting false twist into a length of yarn, both ends of the
yarn are clamped, usually by rollers, and twist is inserted with a false
twister between the clamping points.

164. In practice, yarn twist is described using three
main parameters:
A.Twist direction
B.Twist level (turns/unit length).
C.Twist factor or twist multiplier

165. The effects of the twist on strength
1.Asthetwistincreases,thelateralforceholdingthefibres
togetherisincreasedsothatmoreofthefibresare
contributedtotheoverallstrengthoftheyarn.
2.Asthetwistincreases,theanglethatthefibresmakewith
theyarnaxisincreases,sopreventsthemfromdeveloping
theirmaximumstrengthwhichoccurswhentheyare
orientedinthedirectionoftheappliedforce.Asaresult,at
certainpointtheyarnstrengthreachesamaximumvalue
afterwhichthestrengthisreducedasthetwistisincreased
stillfurther(Fig).

166. filamentyarnwillbestrongerthantheequivalentstaple
fibreyarnasacomparativelylargeamountoftwistis
alwaysneededinastapleyarn.Sometimes
interminglingisusedinsteadoftwist

167. Factors affect by Twist properties
(a)Handle:
Asthetwistlevelisincreaseditbecomesmorecompact
becausethefibresareheldmoretightlytogether,so
givingaharderfeeltotheyarn.
Becauseofdecreaseintheyarndiameter,itscovering
powerisreduced.
Afabricproducedfromalow-twistyarnwillhaveasoft
handlebutatthesametimeweakeryarnthusresultingin
pillingandlowabrasionresistanceoffabric.

168. (b)Moistureabsorption:
Hightwistholdsthefibrestightthusrestricting
watertoenter
Suchahightwistyarnisusedwhereahighdegreeof
waterrepellencyisrequired,e.g.ingabardinefabric.
Lowtwistyarnisusedwhereabsorbencyisrequired.
(c)Wearingproperties:
Withanincreaseintwistlevelwearingproperties
(abrasionandpilling)areimproved.
Highleveloftwisthelpstoresistabrasionasthe
fibrescan’teasilypulledoutoftheyarn.
Thesameeffectalsohelpstopreventpilling(which
resultfromtheentanglementofprotrudingfibres).

169. (d)Aestheticeffects:
Theleveloftwistinyarnaltersitsappearancebothby
changingthethicknessandlightreflectingproperties.
Differentpatternscanbeproducedinafabricbyusing
similaryarnsbutwithdifferenttwistlevels;ashadowstripe
canbeproducedbyweavingalternatebandsofSandZtwist
yarns
Leveloftwistcanalsobeusedtoenhanceorcontroltwill
effect:aZ-twillfabricproducedbyweavingZ-twistyarns
willhaveenhancedZ-twilleffect.SameisthecaseforS-
twill.

170. TwistApplications:
Georgetteismadeofhighlytwistedyarn(upto1000TPM)by
weavingSandZtwistedyarnsalternatelybothinwarpand
weftdirection.
Chiffonismadeinthesamewaybutyarnismoretwisted(up
to2000TPM)andfinerthanthatusedingeorgette-
Cupramoniumrayonisused.

171. Herringboneismadebyusingyarnsofdifferenttypes
andlevelsoftwists.

172. Twistisusuallyexpressedasthenumberofturns
perunitlength,e.g.TPMorTPI.
Howevertheidealamountoftwistvarieswiththe
yarnthicknessi.e.,thethinnertheyarn,thegreater
istheamountoftwistthathastobeinsertedtogive
thesameeffect.
Thefactorthatdeterminestheeffectivenessofthe
twististheanglethatthefibersmakewiththeyarn
axis.
Level of Twist:

173. a fibre taking one full turn of
twist in a length of yarn L. the
fibre makes an angle with the
yarn axis.
For a given length of yarn,
the angle is governed by the
yarn diameter D:
tan θ = пD/L
Thegreaterthediameterofthe
yarn,thegreatertheangleof
twist(forsametwistlevel).As
1/Lisequivalenttoturnsperunit
length then:
tanθ∞Dxturns/unitlength

174. ➢In the indirect system for measuring linear density the
diameter is proportional to 1/√count. Therefore
tan θ ∞ (turns / unit length ) /√count
➢Twist factor is defined using this relationship:
K=(turns / unit length ) /√count(K is the twist factor)
Value of K differs with each count system.
(a)In case of Tex (direct system):
K= TPM x√count
(b) For indirect:
K= TPI (or TPM or TCM)/√count
(Value of K ranges 3.0—8.0 from softer to harder)

175. Sampling :
2-5%randomsampleistakenfrombagsthatareselected
fromtheconsignment.Sayifthereare100bags,thenselect
5bagsrandomlyfortesting.Fromeachbagselectonecone
fortestingandfromeachcone10testsaretobemadethus
total50testing.
Specimen:
Afterconditioning,outerfewlayersfromconeareremoved.
Thenitisside-endwithdrawalandmountedonthetester.
Testmethods:
Followingmethodsareusedtotestthetwist.
MEASURING TWIST:

176. Techniques of twist measurements
1)Direct count/straightened fiber technique
methods
2)Twist contraction/ Untwist re twist
methods
3)Twist to breackmethods
4)Microscopic methods

177. 1) Direct counting method:
Thisisthesimplestmethodoftwistmeasurement.
Themethodistounwindthetwistinayarnandtocounthowmanyturns
arerequiredtodothis.
Asuitableinstrumenthastwojawsatasetdistanceapart.Oneofthejaws
isfixedandtheotheriscapableofbeingrotated.
Acounterisattachedtotherotatingjawtocounttheturns.Samplesare
conditionedinstandardtestingatmospherebeforestartingthetest.
Twist=No.ofTurns/specimenlength

178. Astandardtension(0.5cN/tex)isusedwhentheyarnisbeingclampedin
theinstrument.
Thetwistisremovedbyturningtherotatableclampuntilitispossibleto
insertaneedlebetweentheindividualfibresatthenon-rotatableclamp
endandtotraverseitacrosstherotatableclamp.
Singlespunyarns:aminimumof50testsshouldbemade.Specimen
lengthforcottonis25mmandwoollenorworstedyarns,is50mm.
Folded,cabledandsinglecontinuousfilamentyarns:aminimumof20
testsshouldbemadewithspecimenlengthof250mm.

179. Thistesterhastheextraadvantageofallowingtwisttestsatfixed
intervals.
Thestraightenedfibreprincipleisstillusedfortheactual
measurementofthetwist.
Theyarnpassesfromthesamplepackage,throughaguide,through
non-rotatingjaw,thenthroughrotatingjawandfinallywoundontoa
(clockwork-driven)drum.
2) Continuous twist tester

180. 3) Untwist-twist method or Twist contraction
method :
Thismethodisbasedonthefactthatyarnscontractin
lengthastheleveloftwistisincreasedanditincreasesin
lengthontwistremoving,atlastreachingamaximumlength
whenallthetwistisremoved.
Theyarnisfirstgrippedintheleft-handclampwhichis
mountedonapivotandcarriesapointer.
Afterbeingledthroughtherotatingjaw,theyarnispulled
throughuntilthepointerliesoppositeazerolineonasmall
quadrantscale;jawisthenclosed.
Atthisstagethespecimenisunderasmalltensionandhasa
nominallengthof50cm
Asthetwistisremoved,theyarnextendsandthepointer
assumesaverticalposition,soremovingthetension.

181. Theimageprocessingsystemworkingwithavideo
cameragivesanewandexactwayfordeterminingthe
diameteroffibresoryarnsorthetwistangleofyarns.
Thismethodcomparedwiththeconventionalmethodis
veryquick.Thereportofthemeasurementswiththe
resultsisprinted
4.Image processing system

182. Higher twist multipliers are used,
To increase yarn tenacity and yarn elongation;
To produce lean yarns with low hairiness;
To improve spinning stability;
To obtain a clean-cut fabric appearance; and
To improve the shifting resistance of the yarns.
Lower twist multipliers are selected,
To achieve a soft hand in the final fabric;
To produce bulky and more hairy yarns;
To reduce a yarn‘s tendency to snarl; and
Increase output with the same rotor speed.
Twist multipliers
The twist factor or twist multiplier is a measure of twist, which
accounts for the yarn radius as well as the twist level.

189. 10
Tensile Testing

190. Fibre strength is generally considered to be next to
fibre length and fineness in the order of importance
amongst fibre properties.
Fibre strength denotes the maximum tension the
fibre is able to sustain before breaking.
It can be expressed as breaking strength or load,
tenacity etc.
Elongation denotes elongation percentage of fibre at
break.
TENSILE TESTING

191. There are three types of tensile strength:
Yield strength-The stress a material can withstand
without permanent deformation
Ultimate strength-The maximum stress a material
can withstand
Breaking strength-The stress coordinate on the
stress-strain curve at the point of rupture.
Tensile strength is the ability of a material to withstand a pulling
(tensile) force

192. Molecular structure
No. and intensity of weak places
Coarseness or fineness of fibre
Relative humidity
Elasticity
Factors affecting the strength of
fibres:

193. a)Specimenlength:
Breakingstrengthisthe“loadtobreak”atthe
“weakest”pointofaspecimenofaspecified
length.
Factors affecting tensile results:
c) Capacity of machine:
If a very weak specimen is tested in a machine with very
high capacity, the time to break will be short, so
optimistic result will be produced.

194. b)Rateofloadingandtimetobreak:
Mosttextilematerialsshowanincreaseinbreaking
strengthwithincreasingrateofextensiontogether
withadecreaseinextension.
Duetovisco-elasticnatureoftextilematerial,they
requirecertaintimetorespondtotheappliedstress.
Differenttypesoftextiles(fibres/yarns/fabrics)
responddifferentlydependingonthestructure.

195. D).Previous history of the specimen:Specimen have
been strained beyond the yield point earlier.Specimen
have been subjected to any chemical treatment before test
Effect of humidity and temperature:
Behavior of textile material changes with the relative
humidity of the atmosphere.
Temperature, although have not much effect, but at very
high temperature fibre may be degraded.
Also at very low temperature fibres may be brittle.
E) Clamping problem:
Jaw slip -----> Too low clamping pressure
Jaw damage ------> Too high clamping pressure

196. Threewaystocarryouttensiletest:
1.CRT:Pullingoneclampatauniformrateandtheloadis
appliedthroughtheotherclamp.Whichmovesappreciably
toactuatealoadmeasuringmechanismsothattherateof
increaseofeitherloadorelongationisusuallynotconstant.
2.CRE:Rateofincreaseofspecimenlengthisuniformwith
time(theloadmeasuringmechanismmovesanegligible
distance).
3.CRL:Rateofincreaseoftheloadisuniformwithtimeand
rateofextensionisdependentontheload-elongation
characteristicsofthespecimen.
Principles of Tensile Testing

197. F*r=W*x=mg*Rsinθ
mgR/r =K
F=Ksinθ
1.CRT
Pendulum leaver principles..

199. TENSORAPID (CRE Principle):For tensile testing of single and ply
yarn.
Testing of slivers, leas and fabrics is also possible.
Force measurements up to 1000N without exchanging the force
transducer.
Theclamping force, the yarn tensionersand the suction-off of the yarn
can be programmed.
All numerical and graphical results are displayed on a video screen.
(Histogram, L-E curve, tables, etc.)
Package creel for the automatic measurement up to 20 packages.
Calling-up of test parameters of frequently tested yarn types from the
memory (up to 40).
Pneumatically-actuated yarn clamps; the clamp pressure is
programmable.
Electronic elongation measurement.
Test speed –Continuously adjustable between 50 and 5000mm/min.
2.CRE
Universal strength tester

201. Inconstantrateofloading
(CRL)tests,thespecimenis
loadedataconstantrateand
theelongationisa
dependentquantity.
Theoldestmethodsof
measurementsystem
Itisnotpossibleinconstant
rateofloadingtestsforload
todecrease.Loadmust
increaseallthetime
3.CRL

202. Thank you!