Classification and properties of textile fibres

Structure
1.0Introduction
1.1 Classificationoftextile fibres
1.2 Generalproperties oftextile fibres
1.3 Difference betweencellulose and synthetic fibres
Learning Objectives
After studyingthe chapter you willbe able to understand various terms
associated with fibers.
• Classifythetextile fibers.
• List out various generalproperties oftextile fibres.
• Distinguishbetween thevegetable and synthetic fiber.
Unit Preview
This unit gives the information regarding definition ofterms, staple and
filament i.e. classificationoftextile fibresand generalproperties oftextile fibres.
1.0 Introduction
Theword textileisderivedfromtheLatinterm“texture” forwovenfabrics.
Thus by textiles we understand those objects which have been prepared by
weaving. Textile have an important bearing on our daily lives and everyone
Classification and general
properties of textile fibres
1UNIT

Commercial GarmentTechnology78
needs to know about textiles as we use them in some way or the other. To
understand about textiles the study oftextiles willhelp to a great extent when
we buytextile materials this knowledge willprevent us frommaking mistakes
and we willbe able to purchase good qualitymaterials.
There is a growing demand for textilesand clothing bypeopleofallwalks
oflife.
Yarns are produced bytwisting or spinningofthe textile fibres and in turn
fabric is a structure produced byinterlacing or interloping ofthe yarns..
There are certain terms which are used very often in the studyoftextiles
that are to be understood first. Most ofthe fabrics we use for various purposes
are woven that means theyare constructed byinterlacing sets ofyarns that run
along lengthwise and crosswise directions. Each yarn is made up of several
fibres therefore it is essentialto know or to definethe terms like fibreyarns and
fabrics.
A “fibre “is defined as anyproduct capable of being woven or otherwise
madeinto fabric.It issmallest visibleunit oftextileproduct.Afibrecanbedefined
as a “pliable” hair like strand that is very small in diameter in relation to its
length”. Fibresarethefundamentalunitsorthebuildingblocksusedinthemaking
oftextile yarns and fabrics.
Fibres arethefundamentalunitsusedinmaking oftextileyarnsand later on
into fabric. Thus fibres are the essentialcomponents and basic units and are an
essentialcomponents for making yarns. These fibres areofmanytypes.
Definition ofYarns
Fabricsmadeout ofdifferent fibresareavailableinthemarket. Thecommon
fibres that are used for fabrics are obtained from different sources. There are
few fibres which are naturally available. Still some fibres are synthetised by
usingchemicalsand are knownassynthetic fibreseg. Nylonpolyster and acrylic
fibres.
Some fibresare manufactured byusing raw materialfromnatureand they
are termed as man made fibres. Eg: Rayon, Polynosic, azlon etc.
1.1 Classification of textile fibres
Let us see how fibres are classified
According to the source from which textile fibres are obtained fibres are
broadlyclassified into two ways.

Paper - II Textile Science 79
Vegetable fibres or cellulosic fibres
The fibres that are derived from plants are called vegetable fibres. The
basic materialofallplant life iscellulose. Cellulose is made upofelements like
carbon, hydrogen and oxygen. These cellulose fibres have certain common
properties like low resilience, high density, and good conductor ofheat. They
are highlyabsorbent and are resistant to high temperature. Cotton flax, jute,
ramie are some ofthe examples ofvegetable fibres.
Animal fibres
The fibres which are obtained fromanimals are called animalfibres. Wool
and silk are common examples ofanimalfibres. They are made up of protein
molecules. The basic elements in the protein molecules are carbon, hydrogen,
oxygen and nitrogen. Animal fibres have high resiliency but weak when wet
because theyare bad conductors ofheat.
Mineral fibres
Theyare the inorganic materials shaped into fibres and aremainlyused in
the fire prooffabrics.Asbestos is the example ofmineralfibre. Mineralfibres
are fire proof, resistant to acids and are used forindustrialpurposes.
Vegetable
Eg. Cotton
Linen
Kapok
Jute
Hemp
Animal
Eg. Silk
wool
Mineral
Eg.
Asbestos
Regenerated
Cellulose
Eg. Nitro
cellulose rayon
2. Cupram-
monium
3. Viscose
Rayon
Synthetics
Eg.
polyester,
Nylon,
Acrylic
Acetate
Cellu-
lose
Eg.Nylon
Natural Manmade
Fibres

Man made fibres
These refer to those fibres that are not naturallypresent innature and are
made artificiallybyman. Manmadefibres have highstrength, strong when wet
lowmoistureabsorptioncharacteristics. Examplesofmanmadefibresareviscose
rayon, acetate rayon, nylon, polyester etc. Depending onraw materialchosen
for making ofthe fibres theyareclassified as cellulosic fibres, proteinfibres and
synthetic fibres.
1.2 General properties of textile fibres
1. Staple Fibres
Natural or man made or short length fibres which measures in inches or
fractionofinchexample 3/4 inch to 18 inchesexcept silk allother naturalfibres
are staple fibres. Staple fibres are oflimited length.
2. Filament
Long continuous fibres strands ofindefinite length measured in yards or
meters fibres of continuous length long enough to be used in fabric as such
Naturalsilkfilament is 360-1200 meters. Synthetic filaments canbemade many
kilometers long. The onlynaturalfibre available is silk.
3. Texture
It isthe tactile sensationexperienced when hand is passed over a surface.
Staple fibres and fabrics made fromstaple are lightlyroughwhile filaments and
fabrics made fromfilaments fibres are smooth..
4. Resilience
It means that when fibre is compressed and later when the pressure is
released. It willtend to returnto its originalshape. Resistance to compression
varies fromfibre to fibre.
This qualitycauses the fabric to be wrinkle resistant with the resistance
varying according to the degree of elasticity inherent in the fibre. Wool has
outstanding resiliencywhile it is poorincotton.
5. Luster
It isseenwhenlight reflected fromasurface. It is moresubdued thanshine.
Silk andsynthetics have luster thancellulosic fibres. Infact syntheticshave high
luster whichispurposefullyremoved during spinning.

6. Static Electricity
It is generated bythe frictionofa fabric when it is rubbed against itselfor
other objects. If the electricalcharge that is not conducted away, It tends to
build up onthe surface and whenfabriccomesincontact witha good conductor
a shock or transfer occurs. This transfer maysometimesproduce sparks. This
is morefeelduring hot andhumid conditions.
7. Crimp
Woolfibre ismore or less wavyand has twists. Thiswaviness is termed
as crimp. Finerthewool morewillbethecrimpsinit. Marino woolwillhave30
crimps per inchwhile coarse woolhasonlyone or two. Thispropertyofhaving
crimps gives elasticityto the fibre.
8. Elasticity
It is the abilityofstretched material to return immediatelyto its original
size.
1.3 Difference between cellulose and synthetic fibres
Among natural fibres available cotton, wool and silk are the most
commonlyused fibres for making fabrics.Among artificialfibres rayon, nylon
and polyester are popular. The following are thedifferences betweenvegetable
fibres andsynthetic fibres.
Difference betweenvegetableand synthetic fibre
S.No
1.
2.
3.
4.
Cellulosic fibres
Lowresiliency:Fabricwrinklesunless
anyfinishingisgiven
Highwaterabsorbency:Comfortable
for summer wears, good for towel,
hand kerchiefand diapers.
Cellulosicfibresaregoodconductors
of heat.eg: Cotton is a better
conductor ofheat but less than that
ofrayon.
Identification: Cellulosefibres ignite
quickly, burns freelywithsmoke and
have an after glow and after burning
Synthetic fibres
High resiliency: Less wrinkles
after washing and wearing
Low moisture absorption:
Easilywashable and easyspot
removing.
Synthetic fibres are also good
conductors of heat they melt
withhotorironictouchwithhot
objects.
Identification:Readilyburnsand
melts giving a distinct plastic
burningodour.

Polyesterfibres burnreadilyandquicklywitha chemicalsmell. It continues
to burn after removing fromflame and gives a plastic like in crushable bleed.
Conclusion
Fabrics are made out of different fibres are available in the market. The
growth ofthe textile industryislargelythe work ofthe professionalpersonnel.
New fibres new fabrics and new finishes make new demands for understanding
the importance ofthe textile fabrics and their properties.
Test your understanding-I
State whether the following statements are true or false
1. Our primary needs are food, clothing and shelter (T / F)
2. Fibres are a pliable hair like structure (T / F)
3. Man made fibres are nylon and polyester (T / F)
4. Luster isthe naturaltendencyto returntheir originalcondition(T / F)
5. Static electricityis generated byfriction ofa fabric (T / F)
forms and a greyfeatheryash.
Cellulosic fibreshavehighaffinityfor
dyes.
Cellulosicfibres areresistant to moth
but less susceptibleto mildew hence
damp clothes should not be stored.
Cellulosic fibres need ironing at low
temperatures.Eg:wool
Susceptible to strong mineral and
organic acids stainsthat require acid
treatment should berapidlyremoved.
Synthetic fibres have low
affinityfor dyes.
Highly resistant to moths,
mildew and insects.
Synthetic fibresare adjusted
withhighheatsettings.Hence
it is good for embossed
designing and easy for plant
setting.
Synthetic fibres get readily
damaged due to acids.E.g.:
Nylon
5.
6.
7.
8.

Test your understanding-2
State whetherthe following statements aretrue or false
1. Waviness is terms as crimp (T / F)
2. Examples ofnaturalfibres are polyester and nylon ( T / F)
3. Cottonis a cellulosic fibre (T / F)
4. Woolfabrics gives warmth (T / F)
5. Nylonis first synthetic fibre invented in 1930 (T / F)
Short Answer Type Questions
1. What are fibres ?
2. What are the examples ofvegetable fibres ?
3. What are animalfibres ?
4. What are mineralfibres ?
5. What are man-made fibres ?
6. What is filament ?
7. What is staple fibre ?
8. What is Resiliency?
9. Define Luster and static electricity?
10. Define Crimp ?
Long Answer Type Questions
1. Write the classification oftextile fibres ?
2. What are the generalproperties oftextile fibres ?
3. What arethe differences between cellulosic and synthetic fibres ?
Answers to Test your understanding - I
1. True
2. True
3. True
4. False-resilience

5. True.
Answers to Test your understanding - II
1. True
2. False-synthetic fibres-polyster, nylon
Naturalfibres-cotton,wool, silk
3. True
4. True
5. True

Structure
2.0Introduction
2.1 Manufacture ofhand made cottonin India
2.2 Manufacture ofmachine made cotton
2.3 ByProducts ofcotton
2.4 Properties ofcellulose fibre - cotton
2.5 Fabrics ofCotton
2.6 Finishes for cotton
2.7 Consumer demand for cotton
Learning Objectives
After studying the chapter you willbe able to:
• Understand the manufacturing ofcotton byhandand bymachine.
• Identifythe structure and compositionoffibre.
• Distinguish thevarious properties ofcottonthat is physical, thermal,
chemicaland biologicalproperties.
• Various characteristics ofcotton.
• Understand about cotton fibre blends.
Manufacture and Properties
of Cellulose Fibres - Cotton
2UNIT

• Know the consumer demand for cotton.
• Understand the major end use of cotton.
Unit Preview
Thisunitdealswiththemanufacturingprocessofcottonbyhandandmachine
made, byproducts ofcotton. Thevarious properties suchasphysical, chemical
and biologicalproperteisofcotton, and variousfinishes for cotton.
2.0 Introduction
Cotton is obtainedplant source and it is classified as a naturalmaterialas it
is obtained from the seeds of cellulose seed fibre staple fibre measuring 10-
65mm in length and white to beige in color inits natural state. It is composed
basically of a substance called cellulose. As cotton occupies 50% of the
consumption offibres byweight inthe world it iscalled as the kingofallfibres.
Cotton is the fabric for every home and is the most widely produced of
textile fabrics today. It has now beenproved that India was thefirst countryto
manufacture cotton.Among the recent findings at Mohenjo-Daro were a few
scrapes ofcottonsticking to theside ofa sliversvase. Cottonis thewhite downy
covering ofthe seed grown in the pods. The cotton plant grownin the tropics
needs a climate with 6 months of summer weather to blossom and produce
pods.
Fig. 2.1 Cotton Boll

The cottonfibreis the shortest ofallthe textile fibres. Itslengthvaries from
8/10 ofaninchto 2 inches. Cottonwith short lengthfibresis technicallyknown
as “short staple”. The onewiththe long fibresis called “long staple”and it more
used since it is used for makingfine qualities ofcloth. Long staple is especially
suitable asit is easyto spinand produces astrong smoothyarn. Itis also suitable
for mercerizationa finishing process used to improvethe absorbency, strength
and lusteroffibre.
Cultivation of cotton
Theprincipalcottonproducing regions are Egypt, southernUnited States,
India, BrazilthewesternandsoutherncostofAmericaandEastIndies. It requires
200 daysto continue warmweatherwith adequate moisture andsunlight. Frost
is harmfulto the plant. MarchandAprilmonths are suitable for plantation.
Americaproducesmorethan40%oftheworld’scotton. Indiarankssecond
to the United States as a producer and exporter ofcotton.
2.1 Manufacture of hand made cotton in India
The tools and appliances used bycotton weaves consist ofa spinning
wheel (charkha) and a spindle (takli). The cotton is the first ‘separated’ and
‘carded’. Abow shaped beater known as ‘dhun’is used for the purpose. The
string ofthe bow is placed on the cotton and is made to vibrate bymeans ofa
woodenhammer.These vibrations cleanses allforeignmatter such asseeds and
leaves leavingsoft finecottonbehind. The fine cottonisrolled onstick to forma
cylinder about halfa cubit (6 inches) long and halfan inch in diameter. This is
tied to a spindle or takli. The charkha wheel is turned and the thin thread is
gentlydrawnout untilit is about 300 yards longand rolled on acharkha which
is wound on to a bamboo reel. The yarn is sent to weaving unit where it is
woven into a cloth.
After weaving the cloth is calendared witha blunt beater to giveit a gloss
and to softenit. The cloth is then stamped, ticketed and made readyfor sale.

2.2 Manufacture of Machine made cotton
Preparation: Thefibres are first removedfromseeds inagin. Thisprocess
is called ginning. Everybit ofthe cotton fibre is used in the manufacture . The
fibre mass is then compressed into bales and shipped into spinning mills.
The short ends left on the seeds after the longer fabric. Fibres have been
removed are used in the production of rayon, plastics, dynamite and many
otherbyproducts,whicharethenusedintheproductionofseedoil,hydrogenated
fats, soaps and cosmetics.
Forming the laps: Inthe step dirt fromcottonfibre is removed and fibres
are made in to a soft rollor lap. Thenseverallaps are combined into one.
Carding: These fibres are drawn together to form a loose rope called
sliver.
Doubling: Slivers arecombined here for uniformity.
Combing: Thisprocessis continuationand refinement ofcarding process.
Allcotton yarns for fabrics are carded but not allare combed. Yarns that are
combed are finer evenand freefromallwoodystalkofthe plant. Theyare used
for finer quality fabrics such as voile and organdie. Fabrics made from these
fabrics are expensive too. The slivers are called carded slivers.
Drawing: The slivers is then combined, smoothened and stretched. The
sliversmaybe drawnreduced further insize andgivenaslight twistbyaprocess
Cotton pods
Ginning (RemovalofSeeds)
Lap Formation
Carding
Doubling --> Combing
Drawing
Roving
Spinning

called roving in which the slivers is passed through rollers and wound on to
bobbins set into spindles. It is done ina speed frame.
Roving: Thebobbins areplaced ontherovingframewherefurtherdrawing
and twisting takesplace untilthe cottonstock is about a pencillead in diameter.
Spinning: Doneonthe spinning framewhere the stockpassesthroughsets
ofhighspeed rollers and gives the yarnofdesired thickness.
Weaving and dying:The yarn is then knitted or woven in anyone ofthe
varietyofweaves and structures. Warp yarns are usuallymorestronglytwisted
thanfillingyarnssincetheymustwithstandgreaterstraininweavingandfinishing.
Dye stuffs maybe applied to raw cotton, yarn or piece goods.
Finishing:Itincludesstarching,calendaring,sanforizing,mercerizing orother
finishes as it is necessaryfor the particulars use for which theclothis intended.
These finishes may be applied to yarns but are usually applied to fabric. The
fabrics maybe given these specialfinishes before or after dyeing.
2.3 By products of cotton
Cotton linters: Linters are short, fuzzy fibres that remain on the seeds
after theyhave beenseparated fromthe fibre inthe cotton gin. Theyareused in
the manufacturing ofrayonand acetates, plasticsand photographic film.
Fig. 2.2 Cross Section Fig. 2.3 Cotton Fibre under the microscope
Hulls: These are outside portion ofthe cotton seeds rich in nitrogen and
used as fertilizers, paper cattle feed.

Inner seed: It yields cotton seed oilwhichis used as cooking oils and in
the manufacturingofsoap.
2.4 Properties of cellulose fibre- cotton
1. Physical properties
a. Structure:Thecottonfibreisshort (1/2inch-2 longinch)andcylindrical
ortubularasit grows. Thecottonfibreisessentiallycelluloseconsistingofcarbon,
hydrogen and oxygen. Bleached cotton is almost pure cellulose raw cotton
contains about 5% ofimpurities.
b. Strength: Cottonfibre is relativelystrong which is due to the intricate
structure and70% crystalline.
c. Elasticity: Cottonisrelativelyinelasticbecauseofits crystallinepolymer
systemand for this reason cottontextile wrinkle and crease readily.
d. Hygroscopic moisture: Cottondoesnot hold moisture so wellas wool
or silk but absorbs it and so feels damp much more quickly. It also rapidly
spreadsthroughout the material.
e. Electricalproperty: Thehygroscopic nature ordinarily prevents cotton
textile materials fromdeveloping static electricity.
f.Absorbency:As cotton has cellulose it is a good absorbent offibre.
2. Thermal properties
Cotton fibres have the ability to conduct heat energy, minimizing any
destructive heat accumulationthus theycanwithstandhot ironing temperature.
Drap ability: Cotton does not have good body to drape well in shape.
The type ofconstructionofthe fabric mayimprove this property.
Resilience: Cotton wrinkles easilysome wrinkle resistant finishes may
reduce this property.
Cleanliness and wash ability: Though cotton absorbs dust due to its
rough nature. It canbe washed easilyin the hot water andstrong soaps without
damaging the fibre.
Lustre:Thenaturalcottonhas no pronouncedlustre. This canbeimproved
bythe mercerizationfinishofthe cotton(that issodiumhydroxide treatment).
Shrinkage: Thefibre itselfdoes not shrink but cottonfibrewhichhas been
stretched in the finishing process tends to relaxback creating shrinkage.

Heat conductivity: Cotton is the better conductor ofheat than woolor
silk but not as good as rayon.
3. Chemical properties
Action of acids and alkalies
Strong acids willdestroythe fibres immediately. Diluteinorganic acids will
weakenthe fibre and ifleft drywillrot it. Therefore after treatment withacidic
solutions cottonarticles should be thoroughlyrinsed inwater. Theyare affected
verylittle byorganic acids. Theyarealso quite resistant to alkalisevento strong
caustic alkalies at hightemperature and pressure.
In 8% NaOH cotton fibres swells, spirals, twisted uncoiland shrinks and
become thicker. The resultant fibre issmoother, lustrous, and strongerand has
increased water and dye absorption.
Effect of bleaching: These have no effects until used in uncontrolled
conditions andwith heat.
Effect of sunlight and weather: Ultraviolet rays of sunlight affect the
strength offibre and change the colour to yellow whenexposed to prolonged
period. Pollution also effect fibre.Concentrated and diluted mineralacids like
sulphuric acids willdiscolour fibre .
Affinity to dyes: Cottontakes in dyes better than linen but not as readily
as silk and wool. If a mordant is used cotton is easy enough to dye mordant
colours, direct or substantive dyes should be applied to the cotton.
Effect of perspiration: Both acidic and alkaline perspiration discolours
the fibre.
4. Biological properties
Resistancetomicroorganisms:Themildewandbacteriadamagescotton.
Resistance to insects: Moths and beetles willnot affect or damage the
cotton. But the sliver fish eatsthe cotton cellulose.
2.5 Fabrics in cotton
Flannelette and flannel:Asoft napped cotton fabric its warmth in wear
is due to the fact that the nap traps a layer ofair between the bodyand the cold
outside. Incompositionit isthesameasordinarycotton,buttreatment inweaving
makes it veryinflammable. For this reasonattempts have beenmadeto make it
fireproof bysaturating the fibre with metallic salt, but ingeneralfire proofing
does not withstand washing.

Organdie: Athin light fabric in plain weave with a verystiff finish. It is
madefromgoodqualitycombedyarn. Theyarnis made fromlongstaple cotton
and is spunis withmanytwists. This along withthefinishing process produces
its characteristic transparent crispness. The aimis to give a permanent finish.
The fabric is used for summer and evening wear.
Muslin: This is a cool, very light, and plain weave cloth also used for
summer wear. The name derives fromthe city ofMosulwhere the fabric was
first made muslins wear not always plain, silk and even gold stripes woven in
whenmade inmosul but as cottonwas grownmore plentifullyand the women
could spinyarns ofgreat fineness, cotton yarns graduallysuper seeded silk.
2.6 Finishes for cotton
The resinandthenonresinfinishesgivethecottonsomeeasyand minimum
care features of as synthetics.Advances in antibacterial mildew resistant and
flame resistant treatmentshave improved the effectivenessofthe performances
ofcotton invarious end uses.
Regular finishes like singeing for smoothness mercerization for strength,
lurtre andaffinityfor dyes, sizing and calendaring for lustre, maximumstiffness
bodyand smoothness.Specialfinishlike sanforizing formaximumpre shinking,
crease resistant, antibacterialfinishes, mildew and rot treatment napping for
softness, warmth, absorbencyand mothrepellent treatment are common.
Fibre blends
Amongthevarioustypesofblendsavailableinmarkettodaypolyster, cotton
terycotton, silk, linencotton, viscose rayonandcotton and nylon.
Reasons of blending are:
To facilitate processing.
-To improve properties like dimensionalstability.
- To produce better performance.
- To improve textute, hand or feelappearanceoffabrics.
- To produce multicolor fabrics.
- To reduce cost.
2.7 Consumer demand for cotton
Versatality: Cottoncanserve for food (cottonseedproducts) forclothing
and for shelter. Cotton fibre canbe spun alone or it can be blended with other

textile fibres such as linen, wool, silk, viscose rayon, polyster, nylon. It serves
the purpose of clothing or apparel, home furnishing and industrialfabrics by
giving comfort, durability, fashion and easefor care etc.
Durability: Due to naturaltwist cottonspinsso wellthat it canbe twisted
verytightly. Hence tightlytwisted yarnsproduce durable fabrics.
Comfort: Cottonconducts heat awayfromthe bodyand allowsthe cooler
temperature outside to reach the body, so it is a cool materialfor summer or
tropicalwear. Knitted cotton is used as comfortable wear.
Fashion rightness:Fashiondesigners ofvarious countrieshaveconsidered
cottonglamorousenoughto include intheir collections.
Ease ofcare: The factors oflight, laundering, ironingand perspirationare
commonconsideration incolor fastness to cotton.
Economy or price: Cotton materials are flexible to fit into all types of
economic group. Byproducts ofcottonare used for manypurposes.
Major end uses
Cotton is used forhome furnishing : Towels are most common as it is
highinabsorbency, wide range ofcolors, washabilityand durability. Sheets and
pillow cases aremostlyblends ofcottonwithpolyester or made ofpure cotton.
Drapes, curtains and upholsteryfabrics are made ofcotton and its blends.
Since cotton can be autoclaved at high temperatures, absorbency,
washability and low static build up are important factors for use of cotton in
hospitals.
Industrialuses includebook bindings, luggages, and handbags, shoes and,
slippers, tobacco cloth, woven wiping cloths as andwallcovering fabrics.
Wide range ofwearing apparels: blouses, shirts, dresses, childrenwear,
active wear, separatesswimwear, suits, jackets, skirts, pants, sweaters, hosiery,
bedspreads, comforters, throws,sheets, towels, tablecloths,tablemats, napkins.
Consumer Demand for Cotton
Versatality Economy Durability Comfort Fashion Ease of Care

Conclusion
Cotton continues to be the world’s major textile fibre despite of many
synthetics. It is the oldest and most versatile ofall fibres with good properties
when blended withother fabrics. The mainreason for use ofcottonis its good
weaving qualities, low cost, high absorption, excellent, abrasion, stability to
repeatedblending. Itcanbesafelyironedevenat hightemperatureof425degrees
F. It has excellent wash and wear and wrinkle resistance and also good ifresin
treated.
I. Test your understandings
State whether the following statement are true or false
1. Cotton does not have color retention property. ( T / F )
2. Cottoncannot be blended withother fibres. ( T / F )
3. Cotton conducts heat awayfromthe body. ( T / F )
4. Cottonis used for home furnishings. ( T / F )
5. Cottonis moth repellent and provides softness and warmth. ( T / F )
II. Test your understanding
State whether the statements are true or false
1. Cotton is naturalfibre. ( T / F )
2.The cottonwith short length fibre is called as short staple. ( T / F )
3. Hulls are inside portion ofcotton seeds. ( T / F )
4. Cotton is not good absorbent. ( T / F )
5. Cotton is a good conductor ofheat. ( T / F )
1. What is staple?
2. Give the steps for recent advances in handmade sector?
3. What are the by products ofcotton?
4. What are physicalproperties ofcotton?
5. What are the uses ofcotton?
6. What are the reasons for fibre blends in cotton?

1. What are the chemicalproperties ofcotton?
2. What are the steps involved inpreparation ofmachine made cotton?
3. Write short notes onfollowing
(a) Kapok (b) Flannelette and flannel(c) Organdie
4. What are the characteristics ofcotton?
6. Write the consumer demand for cotton?
Answers for text yourunderstandings - I
1. False
2. False
3. True
4. True
5. True.
Answers for text your understandings - II
1. True
2. True
3. False-outside
4. False-due to cellulose fibre it is good absorbent.
5. True.

Structure
3.0Introduction
3.1 Historyofsilk
3.2 Productionof silk
3.3 Historyofwool
3.4 Manufacturingofwool
Learning Objectives
After studyingthis unit, you willbe able to
• Understand the varioustypes ofsilk.
• Explainthemanufacture ofsilk
• Describe the physicaland chemicalproperties ofsilk
• Explaintheclassificationofwool
• Understand manufacturingprocess ofwool.
• Explain the physicaland chemicalpropertiesofwool.
Unit Preview
Thisunitgivesustheinformationregardingthe manufactureofphysicaland
chemicalproperties ofprotein fibres.
Manufacture and Properties
of Protein Fibres
3UNIT

(1) Silk (2) Wool
3.0 Introduction
Silkisconsideredas“Queenofalltextilefibres”asit hasbeautyandelegance
and good properties ofperformance. Silk is the naturalproteinfiber obtained
from silk worm cocoons. Japan is known for producing best variety of silk.
India produces different varieties of silk and is famous for hand woven silk
textiles. There is a tremendous silk production increase in recent years. The
production ofsilk is called Sericulture. To obtain qualityand quantity ofsilk
rearing conditionsare controlled carefullythroughoutthe life cycleofsilkmoth.
These are two types of silk mulberry or cultivated silk and wild silk.
Cultivated silk iscreamysilk white oryellowishwhite in color. White wild silk
color rangefrombrownish to goldenyellow incolor.
3.1 History of silk
Sericulture or silk production has a long and colorfulhistoryunknown to
most people. For centuries the west knewverylittle about silkand people who
made it pliny, the romanhistorianwrote inhis naturalhistoryin70 BC“silk was
obtained byremoving the down fromleaves withthe help ofwater”. For more
than 2000 years these Chinese kept the secret ofsilkaltogether to themselves.
According to legend the beginning ofhistoryofuse ofsilk as textile fibre goes
back to 260 BC. When fourteen year old wife ofChinese emperor Huang-Ti
discoveredthe secret ofdrawingthe filament fromcocoonofthe silk wormand
producingafabricfromthe filament.This youngprincess Si-ling-chiis knownas
‘godess ofsilk worms’and isthe centre ofreligiousceremonies connected with
the care ofsilk worms and the production ofsilk has long been an important
factor ineconomyofempire.
Silk has never lost its luxuryfieldappealand todayis shownbyallhouses
in their top fashion products some designers are working only on silk. It is
everywhere in fashionpicture. In intimate wearand outer wear, hand bags and
shoes.
3.2 Production of Silk
Silk worms feed on mulberry tree leaves and therefore for rearing them,
the growingofmulberry treesis the first essentialstep. These are grownbythe
agriculturists.
Silk worms havea short life ofonlyabout two monthsand during which
these pass through the following four stages1. Egg 2.wormor larvae 3. Pupa
and 4. moths.

Silk worms are made to lay eggs on specially prepared paper for this
purpose. Theeggscanbestored incoldstorageforsixweeks. Eggs arecollected
and kept at low temperature untiltheyare hatched. Eggs take tendays to hatch
Emerged caterpillars ofant head size are fed on fresh mulberryleaves.At this
stage the wormneeds specialcarebamboo trays with straw mats are provided
for them. Whenthe caterpillar is about eight weeks old it secretesaviscousfluid
fromtwo glandsonits head whichoozes out fromthe commonopening near its
mouth. The fluid is called ‘fibrion’.At the same time it also secretes a gummy
kind offluid called ‘sericin’whichpasses throughthe sameopening. The fibroin
gets hardened whenexposed to air. Thesilk wormspins around itselfto forma
cocoon. Thecocooncontains 2000 to 4000yards ofreelablesilk. Forseparating
thesilkthreadfromthe cocoons theyareimmersed inhot water.Thisimmersion
also kills the warminside. Thenthe cocoons are dries and stored.
Fig. 3.1Silk moth and eggs Fig. 3.2Larva ofItalianBombyx
mori silkworm moth
Fig. 3.3 Cocoon of Bombyxmori Fig. 3.4 Male Bombyxmori or mul-
berry-feeding silk wormmoth

Reeling: Theprocess ofunwinding the filament fromthe cocoonis called
reeling. The care and skillin the reeling operation prevents defects in the raw
silk.Asthe filament ofsingle cocoonis too finefor commercialuse, threeto ten
strands are usuallyreeled at a timeto produce the desired diameter ofraw silk
thread. Several cocoons are placed in hot water to soften the gum and the
surfacesarebrushedlightlytofindtheendsthefilaments. Theseendsarecollected,
threaded througha guide and wound on to a wheelcalled ‘reel’.
Throwing:As thefibres are combined and pulled onto thereel, twist can
be inserted to hold the filaments together. This is called as throwing and the
resultingyarnis‘thrownyarn’. Thisyarnlatergoestoweavingorknittingindustry
based the type of yarn produced.
Spinning: Short ends ofsilk fibres fromthe outer and inner edges ofthe
cocoons and frombroken cocoons and spuninto yarns in a manner similar to
that usedfor cotton. This is called spun silk.
Degumming: Sericinor gumup to 30% ofthe weight ofthe silk fibre. It is
not usuallyremoveduntilafter the clothis wovenbecause servesas warp sizing
that protects theyarns frommechanicalinjuryduringweaving. Sericinremains
onthefibreduringreeling and throwingbeforefinishing, the gumis removed by
boiling the fabric in soap and water. The presence ofgumand sericinincreases
the tendencyfor the silk to water spots on fabrics when ironed.
Bleaching: Silkthread is treated with hydrogen peroxide.
Dyeing: Silk has great affinity for the dyes. Acid dyes produce brilliant
shades on silk.
Printing: Silk maybe left plainormaybeprinted byanymethodlike roller
printing, Screenprintingorblockprinting.Silksareusuallydriedandthenprinted.
Finishing: Silk fabricsrequire veryfew finishes becausetheyhave natural
lustre, softnessand drapability.
Weighting of silk: When silk is boiled to remove the excess of natural
gumorsericinit loosesweight. Thislossofweight isreplacedthroughtreatment
bymetals liketin, aluminiumetc inwater solutions. These arenot removed by
washing.
Weighted silk isnot durable because sunlight and perspirationweakens
fibres. Heavyweighting causes silk to crack.

3.2.1 Various types of silk
Wild silk: Silkproduced bymoths ofspecies other than bombyxmori. It
is brown incolor more uneven and coarser. It is usuallycalled Tussar silk.
Waste silk orsilk noil: Short ends ofspunyarns or inblends with cotton
or wool. Sometimes it is called waste silk.
Dupion: Silk yarns made fromtwo cocoons that have beenformed in an
interlockedmanner.Theyarnisuneven,irregularandlargethanregularfilaments.
It isused inmaking shantungand duppioni.
Raw silk: Silk that has not had anydegumming.
Spun silk:Yarns made fromshort fibres frompierced cocoons and short
ends and outside and inside the edges ofcocoons.
3.2.2 Properties of silk
Microscopic structure
Silkhas itsuniqueproperties. It issoft, supple, strong lighterinweight than
anyothernaturalfibre. Silk is priced for itsweight. Silk is anaturalproteinfibre
where the protein fibroin is held bya gummysubstance .
Fig. 3.5 Microscopic structure of silk
Microscopic properties
Strength: Silk is the strongest naturalfibre. It has a tenacityof2.4 to 5.1
grams per denier. More over smoothness ofthe silk filament yarn reduces the
problemofwearfromabrasion. The strengthofthe spun silk yarns depends on
the lengthofsilk staple.

Shape and appearance: Silk filaments are very fine and long. They
frequentlymeasure about 1000 to 1300 yards inlength. The widthofthe silk is
from9 to 11 microns.
Elasticity: It is an elastic fibre and its elasticityvaries as it is naturalfibre.
Silk fibre maybe stretched from1/7 to 1/5 its originallength before breaking.
Cultivated degummed silk viewed longitudinally under a microscopic,
resembles a smooth transparent rod under microscope. Silk in the gum has
rough irregular surface. Wild silk tend to be quite uneven and is some what
dark. It mayhave longitudinalstriations.
Resilience: Silkretains the shape and resists wrinkling rather well. This is
more in fabrics made frompure silk rather than spunsilk or weighted silk.
Drapabilty: Silk has a pliabilityandsuppleness’ that aided byits elasticity
and resilience givesit excellent drapability.
Heat conductivity: Since silk is a proteinfibre. It is a non conductor of
heat like wool. Hence it is used for winter apparel.
Absorbency:The good absorbtive propertyofsilk also contributes to its
effect inwarmer atmosphere. Silk generallyabsorbs about 11% ofits weight in
moisture whichmakes silk for easydying and printing.
Cleanliness andwashability: Silkis hygienicmaterialbecauseitssmooth
surface does not attract dirt. It canalso be easilycleaned bymild soapsand dry
cleaning.
Shrinkage: Dueto the filament inlength, smoothsurfacesilkhave normal
shrinkage which can be easilyrestored by ironing at moderate heat and damp
conditions.
Effect oflight: Continous exposureto light weakens silkfaster thaneither
cottonor wool.
Chemical properties
Resistance to mildew: Silk willnot be affected bymildew unless left for
time in damp state or under extreme conditions oftropicaldampness.
Reaction to alkalis: Silk is not as sensitive as wool to alkalis. It maybe
affected inconcentrationsand hightemperatures. Coldconcentrated solutions
ofalkalisuchas soda or causticpotashhas slight actiononsilk. Heated solution
dissolved silk.

Reaction to acids: Concentratedmineralacids dissolve fasterthanwool.
Organicacidsdo not harmthemwhilemediumconcentrated HCL willdissolve
silk.
Affinityfordyes: Silkhasverygoodaffinityforaciddyes butlight fastness
isunsatisfactory.
Resistance to perspiration: Silk fabrics are damaged by perspiration.
The silk itselfgets deteriorated in the presence ofperspiration.
Reaction to bleach: Strong bleaches contain sodium hypochlorite will
deteriorate silk. Mild bleaches like sodium perborate and hydrogen peroxide
maybe used with normalcaution.
3.2.2 Uses of silk
Silk isanexpensive luxuryfabricusedformakingdifferent garments. Silkis
used primarilyin apparelandhome furnishing items becauseofits appearance
and cost. Silk is extremely versatile and can be used to create a variety of
fabrics fromsheer chiffons to heavybeautifulbrocades and velvets. Because of
silk absorbency it is appropriate for warm weather wear. Because of its low
conductivityit isusedforcoldweatherwear,also infurnishingsilkisoftenblended
with otherfibres to add soft luster for furnishing fabric. Occasionallyexpensive
hands made rugs are made fromsilk.
3.3 History of Wool
Woolhas the one ofthe first fibres to be converted into fabric. Woolfibre
grows from skin of sheep. It is composed of protein known as keratin. It is
crimp and has scales on its surface depending upon the breed of sheep. The
naturalproteinfibre consist ofamino acids. Woolhas 19 amino acids, keratin,
proteinandother organic acids.
Man uses woolas clothing in the veryearlystages ofhuman history. The
primitivemanisused it intheformofskinofcertainanimals to protectas wellas
to decorate his body. Man then discovered the use of hair of sheep after
interlocking and twisting themtogether under pressure and thus hair ofsheep
were used in making fabrics The interlocking of woolen fabrics is known as
felting.
Wool was probablyknown to the primitive man as he used sheep skin to
cover his bodyeven before the discoveryofother fibres.

Woolis yellowishwhite fibre and has mediumluster. It isconsidered to be
weak fibre than manyother fibres however other properties suchas resiliency
and elasticitycompensatefor low strength.
3.3.1 Structure of wool
When the wool is fibre is untwisted it shows a kinky appearance. The
length varies from 1,1/2 to 18 inches, the long fibres are coarser than short
fibres.
Fig. 3.6 Microscopic structure ofWool
When observed under microscope the surface ofthe fibre seems to be
consisted to scales irregular ofshapeand slightlyoverlapping likescales offish.
3.3.2 Classification of wool
1. Merino wool: Merino sheep produce the best quality wool which is
originated fromSpain.
Classification by fleece
1. Lamb’s wool: The first fleece sheared from lamb about six to eight
months old is known as lambs wool. This is in fine qualityand soft texture.
2. Hogget wool: Woolobtained fromsheep of12 to 14 months old that
has not been previouslyshorn.
3. Pulled wool: When sheep is slaughtered for meat the wool is pulled
called as pulled wool.
4. Cotty wool: Verypoor grade wool.

5. Wetherwool:Anyfleececlipped after the first shearing is called weter
wool.
3.4 Manufacturing of Wool
Shearing
Sheep are generallyshornoftheir fleeces inspring but thetime ofshearing
differs indifferent parts oftheworld. Machine clippers removethe fleece faster
and closer thanhand clippers. Superior woolvarietycomes fromthe sides and
shoulderswhereitgrowslonger, finerandsofteristreatedasgoodqualityfleece.
Wool fromthe chest ,bellyand shanks is treated as a second fleece.
Preparation
An average about 8 pounds of fleece is made from one sheep. Then the
fibers are packed in bags or bales. The raw wool or newly sheared fleece is
calledGrease woolbecauseit contains thenaturaloilofthesheep. WhenGreese
wool is washed, it loses from 20 to 80% of its original weight. The grease
known as yolk is widely used in the pharmaceutical industries for lanolin
compounds.
Sorting and grading
Skilledworkersdo woolsorting. Eachgradeis determined bytype, length,
fineness, elasticityand strength. Separating offibre bytouchand sight.
Scouring
Washing ofraw woolis analkaline solution is knownas scourcing. The
woolis treatedwithwarmwater, soap, mild solutionofsoda ashor other alkali
to remove dirt inthe fibres.
Iftherawwoolisnotsufficientlyclearof vegetable,substanceafterscouring
is put through the carbonizing bath. The fibres are then put through a dilute
solution ofsulphuric or hydrochloric acid which destroys anyvegetable. This
process is called as carbonizing and resultant woolis called ‘extract’.
To remove the Grease and dirt in raw wool it is put through a series of
naphtha balls followed by clear water to remove the naphtha. This is called
naphtalation. This process improves the dye uptake propertyofwool.
Garnetting
Recycled woolfibres are obtained byseparatelyreducing the unused and
used fibrous mass bya picking and shreddingprocess called garnetting.

Drying:Woolis not allowed to become absolutelydryusuallyabout 12 to
16% ofmoisture is left inwoolto conditionit for subsequent handling.
Oiling:Aswoolis unmanageableafter scouring the fibreis usuallytreated
with various oils including animals, vegetable, mineral or a blend of these to
keep it frombeing becoming brittleo lubricate it for the spinning operation.
Dyeing: If the wool is to be dyed in raw stock it is dyed at this stage.
Some woolfabrics piece dyed, some are yarn or skin dyed and some are top
dyed.
Blending: Woolof different grades or pure wool fibres and other textile
fibers maybeblended mixedtogetherat thispoint.Alltheinformationshould be
present onthe labels.
Carding: Thecardingprocessintroduces theclassificationofwoolenyarns
andworsted yarns.It makesthe fibreparallelandsomeamount ofdirt isremoved
due to straightening of fibres. Fibres are used for the worsted yarn are more
straightened thanthe woolyarns.
Gelling and combing: The cardedwoolwhichis to bemade into worsted
yarnisput throughgillingandcombingoperations. Thegeillingprocessremoves
the shorter staple and straightens the fibre. This process removes short fibres
from1 to 4 inch lengthplaces the long fibre as parallelas possible and further
cleans the fibre byremoving any remaining loose impurities.
Drawing: Drawing is an advanced operation for worsted yarns which
doubles and redoubles slivers ofwoolfibres. The process draws, drafts, twists
andwindsthestockmakingsliversmorecompact andthinningtheminto slubbers.
Roving: This is the final stage before spinning roving is actually a light
twisting operationto hold thinslubbers intact.
Spinning:Inthespinningoperationthewoolrovingisdrawnoutandtwisted
into yarn. Woolen yarns are chiefly spun on the mule-Spinning machine are
worsted yarns arespunonanykindofspinning machine mule, ring, cap or flyer.
3.4.1 Properties of wool
Physical properties of wool
Strength: It is stronger thansilk. Whenwet woollooses about 25% ofits
strength. Longerthe fibre the greeter willbe the strengthofyarn.
Resiliency: Woolis highlyresilient and comes to its originalshape when
hanged afterwrinkled or created.

Stretchability: Wool is highly elastic. It is about 10 to 30% stretched
when dry and 40 to 50% when wet upon receiving pressure upon drying it
readilyregainsitsoriginaldimensions.
Shrink ability: Woolis resistant shrinkage. However long exposure to
moisture maycause shrinkage.
Effect of friction: Frictionwillsoften the woolfibre especiallywhenwet
and thus isadvantageous inmaintaining smooth, soft texture offabrics.
Crimps: Woolfibre is more or less wavyand has twists. This waviness is
termed as‘crimp’. Finer the woolthe more willbethe crimps init. Merino wool
has 30 crimps per inch while coarse woolhas one or two.
Effect ofmoisture:Woolis the most hygroscopic in nature. It canabsorb
upto50%ofitsweightandcarryupto 20%weight, without giving thefeelingof
being wet. Upondrying it losses moisture slowlypreventing rapid evaporation
thusavoidingchillingfeelto theuser. It absorbsperspirationafterviolent exercise
and guards the bodyagainst suddenchange intemperature.
Heat conductivity: Woolfibre is a part is a poor conductor ofheat and
therefore thefabrics made fromthe fibre are considered most suitable as winter
wear.
Felting:Woolfibresinterlockandcontract whenexposedto heat, moisture,
and pressure. The scale like exterior of the fibres contributes to felting. The
fibres get softenedinweak alkaline solutionsdue to expansionofscales at their
free edges, withfriction and pressure theyagain interlock to forma felt. This
property is used in making felts for hats, shoes, floor-coverings and sound
proofingpurposes.
Effect of heat: Low heat has no effect but strong heat weakens the fibre
and destroys the colour ofthe fibre.
Chemical properties
Actionofacids:Diluteacidshavelittleeffect but eitherhotorconcentrated
acids weaken or dissolve the woolfibres.
Action of alkalis: Alkalis tend to make while wool yellowish, strong
solutionsofsodiumcarbonatewhenheateddestroys thefibre sodiumhydroxide
ishighlyinjurioustothewoolfibre.Howeverboraxandammoniahavenoharmful
influenceonwool.

Action of bleaching agents: Strong bleaching agents like hypochlorite
have harmfuleffects on wool., potassiumpermanganate, sodiumperoxide and
hydrogenperoxidehowever cansafelybeused for bleaching andstainremoval.
Effects of moth and mildew : Wool is easilydamaged by moths that is
whyduringstorageofwoolengarmentsspecialcaseisneeded.Howevermildews
donot effects garments.
Finishesgiventowool:Felting,fulling, mothproofing,crabbing, decanting,
londonshrinking, napping, singeing and steaming.
Wool blends: Woolpolyster, woolacrylic, woolnylon, silk and wool.
3.4.2 Uses of wool
The majorityofwool(72.8%) is used in apparel, home furnishing account
for 15-45%, industrialuses 6 to 7% and exports 5%, woolaccounts for 3.3%
ofallfibres for apparel.
The mostimportant useofwoolis forapparelcoats, jackets, suits, dresses,
skirts, slacksmade fromwovenfabricsofvarying weights andknitted fabrics’.
Allthese givesthe warmthgarments and withgood tailored look.
In the home furnishing area the major use of wool is in carpets and rugs
where woolis used more, cover to the carpets andwarmin the rugs. Blends of
different syntheticfibreswithwoolforsuitingmaterialsareincreasinglyimportant.
This result infabrics that are more appropriate inwarmer conditions. Polyester
is the most important fibre used inblending withwool.
Conclusion
Selection of a fibre, should be willing to payfor weaving quality. Agood
quality fibre (either silk or wool) is not cheap and priecs are tending to rise.
Blends offibres with man made and naturalfibres have grown in importance.
The consumer should read the percentage of each fibre and selling point on
label.
I. Test your understanding
1. Silk fibre is the longest ofallnaturalfibres. ( T / F )
2. Theprocess ofunwinding the filament fromthe cocoonis called as
spinning. ( T / F )
3. Silk has great affinityfor dyes.Acid dyes produce brilliant shades on
silk. ( T / F )

4. Wild silk has uneven structure and is some what dark compared to
cultivated silk. ( T / F )
5. Silk fabrics deteriorate and coloris also affected due to perspiration.
( T / F )
II. Test yourunderstanding-2
1. Gradeofwoolisdeterminedbytype, length, fineness,elasticityoflength
( T / F )
2. Washing ofraw woolinalkaline solution is knownas reeling. ( T / F )
3. Woolis non hygroscopic innature. ( T / F )
4. Woolfibres interlock and contract when exposed to heat moisture and
pressure. ( T / F )
5. Bleaching agents have no effect on wool. ( T / F )
6. Wool can be blended bypolster, acrylic, nylon etc.
1. What is filament fibre?
2. What are the physical properties ofsilk?
3. What is the microscopic appearance of silk?
4. What are the uses of silk?
5. What is the microscopic appearance of wool?
6. Write theclassificationofwool?
7. What are the uses of wool?
8. What are the physical properties ofwool?
1. What are the chemicalproperties ofsilk?
2. Write the process ofmanufacturing silk fibre?
3. What are the various types of silk?
4. How do you manufacture woolfibre?

5. What are the chemicalproperties ofwool?Write any4 chemical
properties in detail?
Answer for test your understanding - I
1. True
2. False (reeling)
3. True
4. True
5. True .
Answer for test your understanding - II
1. True
2. False (scoring).
3. False
4. True
5. False (strong bleaching agents like hypochlorite haveeffect on wool.
6. True.

Structure
4.0Introduction
4.1 Rayon Fiber
4.2 Polyster Fiber
Learning Objectives
After studyingthis unit, you willbe able to;
• Understand the manufacturing process ofRayon
• Identifythe structureofrayon fiber.
• Describe thephysicaland chemicalproperties ofrayon
• State the uses ofthe rayon
• State the types ofpolyester yarn
• Understand the manufacturingprocess ofpolyester
• Explainthephysicaland chemicalproperties ofpolyester yarn
• Classifythe types ofrayon.
Manufactured Fibres
4UNIT

Unit Preview
This unit givesus the informationregarding themanufacture andproperties
ofman-made fibers.
(1) Rayon
(2) Polyester.
4.0 Introduction
A rayon fiber was the first man-made composed of pure cellulose the
substance ofwhichis themanconstituentofcellwallsoftreesandcotton. Rayon
fibers are made from cellulose that has been reformed or regenerated.
Consequently, these fibers are identified as “regenerated cellulose fibers”.
Because ofits lustre and soft hand feel, it resembledsilk and came to be known
as “artificialsilk”. However it ismore like cottoninits chemicalcomposition
4.1 Rayon
History of Rayon
Robert Hooke, theEnglish naturalist, had prophesied the production ofa
fibersuchasrayon, thefirstofthe manmadefiberslongago in1664. Hebelieved
thatitwaspossibleto makean“artificialglutinouscomposition”muchresembling,
if not fully like silk worm secretion George Audemars, a Swiss chemist,
discovered howto make cellulose nitrate. In1884, count Hilairede chardonnet
produced the first man made textile fibersfromnitro cellulose. He is known as
“father of Rayon”.
Wood Rayonis produced in manyways. Viscose Rayonis popular among
customers. It is made frompulp and cottonlinters. The otheris cellulose rayon
(acetate rayon) in the chemist terminology, rayon and acetate arenot synthetic
because natural materials- cotton, linters and wood pulp are used in their
manufacture, ratherthanchemicalelements.
4.1.1 Source of Rayon
Rayon is an artificial, man-made or synthetic fibre made from cellulose.
Commercially rayon was produced about 48 years back. Rayon produced at
that timewas verylustrous theywere given this name which means “reflecting
the raysofsun”.
Themainobjectiveinmanufacturingrayonwasto provideacheapsubstitute
for silk. India has been importing rayon fabrics and rayonyarn.

4.1.2 Structure orRayon
When seen under microscope, the fiber appears smooth and rounded.
Viscoserayonfibersarerodlikewithnumerous,longitudinal, threadlikestriations
or lines. These are due to the indentations offiber surface.
Fig. 4.1 Microscopic structure of Viscose Rayon
4.1.3 Manufacture of Rayons
All types of rayon are made from cellulose. There are main four main
procedures bywhichcellulose is transformed into rayon. Theyare
(1) Thenitrocellulose process
(2) Thecuprammoniumprocess
(3) The viscose process
(4) Thecellulose acetate process.
The generalprinciplesofrayonyarnproductioninvolvethefollowing steps.
(a)To treat cellulosechemicallyfor rendering fromit a liquid
(b)To force theliquidthroughfine holes
(c)To changefromliquid streaminto solid cellulose filaments.
The Viscose Process
This is discovered in 1892 in England. In this process Spruce, a type of
treechipsareused. Sprucelogsarereducedtowoodpulpandpurifiedforcellulose
base. Wood pulpistreatedwithcausticsoda to formalkalicellulose. It is treated
with carbon disulphide to form cellulose xanthate. This is dissolved in dilute

caustic soda solution.Areddishor orangeliquid is formed. Thisliquid is filtered
and then kept for ageing untila thick fluid is formed whichis called ‘Viscose’.
This fluidisforcedthroughfinejets into a dilutesolutionofsulphuricacid. Inthis
waycellulose is regenerated into continuous fibers.
The largest production of rayon today is manufactured by this process.
The cost is low.
4.1.4 Properties of Rayon Fabrics
The development ofman-made fibers possessing along withthe prized
qualities ofthenaturalfiber is a tributeto humaningenuity.
Characteristics of Rayon Fabric
· HighlyAbsorbent
· Soft and comfortable
· Easyto dye
· Drapes well
Physical Properties
Strength :Thetensile strengthofviscoserayonis greaterthanthat ofwool
but is onlyhalfas great as silk. Viscose rayonis also weaker thancottonand its
strengthis reducedto 40 to 70percent whenwet.Yet it produces fairlydurable,
economical and serviceable fabric whose smoothness of surface favorably
withstands withfrictionofwear
Elasticity : Viscose rayonhas greater elasticitythan cottonbut less than
wool and silk. While viscose rayon fabrics have some inherent extensibility,
undue strainmight cause themto sag or even burst.
Cellulose
Steeping
Dissolving
Xanthation
Filtration
Extrusion

Resilience : Viscose rayonlacks the resilience. It should be remembered
that the resistance ofa fabric to creasing depends on the kind of yarn, weave
and finishing process.
Drapability : Viscose rayon possesses a marked quality of drapability
because it is relativelyheavyweight fabric.
Heat Conductivity : Viscose rayon is a good conductor of heat and is
therefore appropriate forsummer clothing like cotton.
Absorbency :Viscose rayon is one ofthe most absorbent ofalltextiles. It
is moreabsorbent than cotton or linen, but less thanwooland silk.
Cleanliness and Washability
Because of smoothness, Viscose rayon fiber helps to produce hygeinic
fabrics that shed dirt. Since Viscose rayons temporarilylooses strength when
wet, it must be handled withcare when washed.
Reaction to Bleaches : Household bleaches containing sodium hypo
chlorite, sodiumperborateor hydrogen peroxide maybe safelyused.
Shrinkage :Viscose rayonfabrics tend to shrink morethancottonfabrics.
SpunViscose rayon fabrics shrink more, which can be givena shrink resistant
finish, suchas Sanforset.
Effect ofHeat :Viscoserayonis purecellulose fiber whichburnsas cotton.
Whenironing, onlymoderatelyhot temperature must be used.
Chemical Properties
Resistance to Mildew : Like cotton, Viscose rayon have tendency to
mildew. Suchfabrics should not beallowed to remainindamp conditions.
Reaction to Alkaline : Concentrated solutions of alkalies disintegrate
Viscose rayon.Amild soap withlukewarmwater is recommended in washing
rayons.
Reaction toAcids : Beingpure cellulose, thefabric is disintegratedbyhot
dilute and coldconcentrated acids similar to that ofcotton.
Affinity of Dyes : Viscose rayon fabrics absorb dye evenly and can be
dyed with a varietyofdyes, like acid, chrome, and disperse.
Resistance to Perspiration : It is fairly resistant to deterioration from
perspiration.

4.1.5 Uses of Rayon Fiber
Apparel:Accessories, blouses, dresses, jackets, lingerie, linings, millinery,
slacks, sports shirt, sportswear, suit, ties, work clothes.
Home Furnishings : Bed spreads, blankets, curtains, draperies, sheets,
slipcovers, tableclothes, upholstery.
Industrial Uses : Industrial products, medical products, non-woven
products.
Other Uses : Feminine hygiene products.
It’s used inindustrialwipes, medicalsupplies, including bandages, diapers,
sanitarynapkin, andtampons in non-woven fabrics.
4.2 Polyester Fiber
Polyester is a synthetic fiber invented in 1941. The first polyester fiber is
known as‘Dacron’inAmerica and ‘Terylene’inBritain. Latervarious types of
polyesters are produced. Terylene fiber is made by synthesizing terephthalic
acid and ethylene glycol.
The ground work for development of polyester fiber is done by W.H.
Carothers. Polyester fiber is the long chain polymer produced from elements
derived fromcoal, air, water andpetroleum. Polyester is a thermoplastic fiber
and has good strength. It melts in flame and forms a grey hard non-crushable
bead. It is an easy care fabric and can be easily washed.
Polyesterfiberlooks like asmooth,glassrod similarto Nylon. Ifdelustered
it shows black spotted appearance. The length, width, shape and luster of the
polyester fibers arecontrolled during manufacture to suit a specific enduse. It is
mostlyblended with other fibers to improve its absorbencyandto lower static
electricity.
4.2.1 Method of Manufacture
Generally each companyproduces its own varietyof polyester through
there are likelymodifications under specific trademarks.
Eg : PET (Principle raw materialis ethylene diamine and terepthalic acid)
obtained frpmpetroleumand PCDT polyester.
Spinning ofFiber
Themoltenpolymerisrigourouslymaintainedatairtightcondition, asoxygen
willaffect its stability. The viscous melt is extruded throughspinneret, and the

filaments are subsequently drawn into desired polyester fiber. Variations in
production process depends on desired end results.
Fig. 4.2 Flow chart of manufacturing process ofpolyester
The holesofspinneret mayberound or modified to be trilobal, pentagonal,
hexagonal or octagonal shapes so as achieve specific effects such a greater
cushioningand insulativeproperties. Other properties maybeobtained withthe
aid ofspecific additives givento the spinning solution.
Upon extrusionofspinneret, the polyester filament does not have allthe
desired characteristics because ofrandomarrangement ofpolymer molecules.
The fibers are therefore drawn or elongated with the aid ofgodet wheels. The
temperature conditions andthe extent to whichthe fibers are drawnto 5 times
theiroriginallength.
Types of PolyesterYarn
The diameterofthe polyester yarnis determined by;
(a)The rateextrusionoffilaments fromthe spinneret.
(b)The number ofspinneret holes and therefore thenumber offilaments

(c)The rate of drawing of filaments. The yarn comes in a wide range of
diameterand staplelengths. The yarnsare producedbasically, as monofilament,
multifilament and spunand sometimes the textured yarnsare also produced.
4.2.2 Properties of Polyester Fabrics
Properties of Polyester
· It resistswrinkling.
· It is easyto launder
· It dries quickly
· It’s resistantto stretching.
Physical Properties
Shape andAppearance : These fibers are generallyround and uniform.
The fiber is partiallytransparent andwhite to slightlyoff-white incolour.
Strength :The PETpolyesters are ingeneral, stronger. Polyester is found
in industrialuses and the highlydurable fabrics.
Elasticity : Polyesterfibers do not havehighdegree ofelasticity.Ingeneral
polyester fiber is characterized as having a high degree ofstretch resistance,
which means that polyester fabrics are not likely to stretch out of shape too
easily.
Resilience : Polyester fibers have high degree ofresilience. Not onlydoes
a polyester fabric resist wrinkling whendry, it also resists wrinkling whenwet.
Drapability:Fabricsofpolyesterfilament havesatisfactorydrapingquality.
Polyester spunyarn is flexible andsofter, therebydraping qualityis improved.
Heat Conductivity : Fabricsofpolyester filament aregoodconductors of
heat. Polyesterstapledoes not providegreater insulationintheyarnsandfabrics.
One ofthereasonfor apparelgreaterwarmthofpolyester isits low absorbency.
Absorbency : Polyester is one of the least absorbent fibers. This low
absorbencyhasimportant advantages- theywilldryveryfast, suited for water
repellent purposes, such as rain wear and theydo not stain easily.
Dimensional Stability : If the polyester is properly heat set, it will not
shrink, norstretchwhen subjected to boiling water, boiling cleaningsolvents or
ironing temperaturesthat are lower thanheat setting temperatures.

Shrinkage : Polyester fabricsshrinks as muchas20 %duringwet-finishing
operationsandtheyare generallyheatset inlater treatments.Theyhaveexcellent
dimensionalstability.
CleanlinessandWashability:Sincepolyesterfibersaregenerallysmooth,
has low absorbency, manystains lie onsurface, and are easilywashed, byhand
or machine but oilstains are veryhard to remove.
Chemical Properties
Reaction to Alkalies : At room temperature, polyesters has good
resistance to weak alkalies and fair resistance to strong alkali. It reduces with
increase intemperatureand alkalies concentration.
Reaction toAcids : Depending upontype, polyester has good resistance
to mineralandorganicacids. Highlyconcentrated solutionsat hightemperatures
cause degradation.
Eg:SulphuricAcid.
Effects of Bleaches: Fabricsofpolyestermaybe safelybleached, because
polyesters have good resistance to deterioration to household bleaches. Ifthe
polyester have opticalbrightener, bleaching is not necessary.
Effect of Heat: Ironing should be done at low temperature. It gets sticky
at 4400
F.
Effect of Light : Polyesterhas goodresistance to degradationbysunlight.
Over prolonged use, gradualdeteriorationoffiber occurs.
Affinity for Dyes : Polyesters are dyed with appropriate disperse,
developed dyes at high temperatures producing a good range of shades and
color fastness.
Resistance to Perspiration : Polyesters has no loss of strength from
continued contact witheither acid oralkaline perspiration.
PolyesterBlends: Polyestercottonblend, polyesterwoolblend, polyester
rayon, polyester silk blend, polyacetate blend, , polyester and nylon are some
common blends.
4.2.3 Uses of Polyester
The most important uses of the polyester is in “woven fabrics”. The
blended fabrics areattractive, durable and comfortable, retain their appearance
welland easycare. The first use of staple polyester was in tropicalsuiting for
men’s summersuits. The suits werelight inweight andmachine washable.

Polyester and polyester blends are also used in home-furnishings, sheets,
blankets, bed spreads, curtains that match bed spreads, mattress ticking, table
clothes. They are used in upholstery fabrics; polyester carpets have a softer
hand thannylon carpets. Spun yarnare used in knitted fabrics. Here polyester
with cottonblends are used.
The other important use where it is used is as fiber fill. Used in pillows,
comforters, bedspreads, other quilted households and apparels, winter jackets
etc.
Non-woven fabric are the fourthimportant use ofthe polyesterfabrics eg:
fusible interfacings, pillowcovers, matress interlining etc.
It has many industrial uses too in pile fabrics, tents, ropes, cording,
fishing line , cover stock for disposable diapers, gardenhoses, sails, seat belts,
filter fabricsused inroad buildings, fertilizer bags, inmedicinalfield for artificial
arteries, veins and hearts.
Conclusion
Consumersaremostlyawareofthefibercontent withfibresandtheirblends.
The man-madefibres likerayon, polyesterto have qualitiesofstability, durability,
comfort, wrinkle resistance ease ofcare etc.
State whetherfollowing statements areTrueor False.
(1) Rayon is the first man-made fibres made fromcellulose. (T / F)
(2) Acetate rayons are rod-like with no striations. (T / F)
(3) Nitrocellulose processis first used for productionofrayon fabrics.
(T / F)
(4) The largest production ofrayon is donebycuprammoniumprocess.
(T / F)
(5) Viscose rayon tend to shrink more than cotton fibers.(T / F)
State whetherthe following statements areTrue or False
(1) Diameter ofpolyester yarn is determined byextrusionoffilaments of
spinneret, no. offilaments and rate ofdrawing filaments. (T / F)
(2) Polyester fabrics are bad conductors ofheat. (T / F)

(3) Polyesters is used for the water repellent purposes and willnot stain
easilydue to its hygroscopic nature. (T / F)
(4) Polyester is unaffected bymoths, carpet beetles, silver fishor other
insects. (T / F)
(5) Polyesterhas good resistance for degradation bysunlight. (T / F)
(1) What is a man-made fiber? Who was the father ofrayon industry?
(2) What is the microscopic appearance ofrayon?
(3) What are the uses ofrayon?
(4) What are the physical properties ofrayon?
(5) What is the microscopic appearance ofpolyester?
(6) What are uses ofpolyester?
(7) What are the physicalproperties ofpolyester?
(8)Write the drapabilityin polyester fiber?
(1) What are the chemical properties ofrayon?
(2) Write the manufacturing process ofrayonbyViscose process?
(3) What are the chemicalproperties ofpolyester?
(4) Write indetail, about manufacturing process ofpolyester fiber?
(5) Explain theuse ofpolyester?
(1)True
(2)False (cuprammoniumprocess)
(3)True
(4)False (Viscose process)
(5)True

(1) True
(2) False
(3) False (due to low absorbency property)
(4) True
(5) True

Structure
5.0Introduction
5.1 Spinning andvarious types ofspinning
5.2Yarns andclassification ofyarns
Learning Objectives
After studying this unit, the student willbe able to
• Understand about the classification ofyarns.
• Know about end uses of plyyarns
• Know about end uses of corded yarns
• Know about noveltyyarns and types
• Understand yarn-twist.
• Explainthe yarncount and balance ofcloth.
Unit Preview
Thisunitgivesustheinformationregardingtheclassificationsofyarns, turst
in the yarns, balance ofcloth yarncount and noveltyyarns.
Spinning and Yarns
5UNIT

5.0 Introduction
Spinningis theprocessofdrawingoutandtwistingofagroupor bundlesof
fibres into a continuous thread or yarn of sufficient strength to be woven or
knitted into fabrics.
In the beginningthe yarns were spunbymane withbarehands without the
aid of any tool and it must have been many centuries before the spindle was
evolved for spinning. The spindle or “takli”stillsurvives as a tool hand spinning
wool, silkand cotton yarn.
It isthe simplest toolwhichconsistsofa rounddisc whichis attachedinthe
center to a thin, smooth rod about inches long. The upper end ofthe rod has a
groove or a hook whichbulkofthe fibres, these are drawn out ina long stand.
The spinner while simultaneouslypulling thefibres, gives a twist to the spindle
and let it go. The spindle whirl around and thus twisting up the pulled fibres
makes a continuousthread. The thread is then wovenround therod above the
disc. The disc provides the necessary weight which quickens increases and
prolonged the revolving of the rod, therebythe twisting ofthe fibre ensures a
strong thread.
Who does not know the “charka” in India. Acharka is used for spinning
yarninthehandloomindustryinIndia. Theyarnspunonthecharkhaisofvarious
qualities.Thefamous“DaccaMuslins”whichwereuncomparablefortheirfineness
but alas are extinct now were wovenofa charka yarn. The inimitable soft and
light pashmina ofKashmir are stillwoven ofthe charkhaspin yarn.
Charkhas are ofvarious types. In the textile industries todayelectrically
driven machines are employed for spinning. Several machines are used to
complete theprocess ofspinning, whichconsists ofstages suchas drawing out
offibre to reduce size and to give slight twist-roving and then spinning. There
are two general methods ofprocedure. In one process, the action ofdrawing,
twisting and winding is continuous and this is called ‘ring’ spinning and in the
other, the drawingand twisting is stoppedwhile the twisted threadis wound up
(as inthe case ofhand spinning) and this is known as ‘mule spinning’. The ring
spinning is a quicker process andhas the advantage ofreducing operating cost
andincreaseproduction,but themulespunisfiner, softerandofgreaterevenness.
In spinning yarns, whether by hand or machine a difference has to be
made inthe yarn intended for warp and weft or filling. The warp yarnneeds a
greater amount oftwists to produce a strong firmthread which is used for the
foundationofthefabric. The yarnisgiventwistsofspecified numberofturns per
inch.At first, a continuous threador a strand is made fromfibres and severalof
these strands are twisted together to get a finalyarn.

Dependinguponthefibres, thepreparatorymethodsofspinningareclassified
into two types:
(1) Chemicalspinning– filament fibres
(2) Mechanicalspinning – for the short staple fibres
Types of Spinning
(1) Chemicalspinning
Chemicalspinningoperationsaregenerallyusedtomakeman-madefilament
fibers to yarns.Aviscous solution is extruded througha nozzle like die called a
spinneret. Man-made fibersare made into yarns bychemicalspinning.
There are three types ofchemicalspinning.
Theyare (1) Wet spinning
(2)Dryspinning
(3)Melt spinning
Wet Spinning
The first commercial method for manufacture of manmade fibre is wet
spinning ofcellulosic fibre-rayon. This process involves the use ofappropriate
liquid solutionwhich is pumped through smallnozzle called spinneret, into a
chemicalbaththat coagulatesthe extrudedsolutionofendlessstrandsoffilaments.
These coagulatedcontinuous fibers are drawnout ofbath, purifiedbywashing,
dried and thenwound onto spools. Theconstructionofspinneret decidesifit is
a mono-filament, if one hole, Multifilament if many holes are present in the
spinneret. The amount of twist givento the processed yarnwillaffect texture
andstrength.
DrySpinning
This processinvolves use offiberliquid solutionwhichispumped through
spinneret into an air chamber. The air reacts with extruded streams, of liquid
Chemical Spinning Mechanical Spinning
(filament fibres (Staple Fibres)
Wet Dry Melt Conventional Direct

fiber causing them to solidify. These coagulated fibers are then drawn out of
chamber, twisted, or processed then wound onto spools.
Eg.Acetate
Melt spinning
Polyester chips obtained fromreacted chemicalcombinations are melted
and thenpumped through spinneret into an air chamber. The extruded stream
cools and solidifies into continuous filaments which are then drawn out from
chamber twisted or processed or subsequentlywounded onto spoons.
Eg. Polyester
(2) MechanicalSpinning
Mechanical spinning refers to a multistep procedure in which machines
physicallymanipulateandspinfibresintoyarns. Therearetwotypesofmechanical
spinning. Theyare(1) Conventionalspinning
(2) Direct spinning
Conventionalspinningis used to makeyarns fromnaturalstaplefibres and
some man-made fibers. It involves series ofmachine operations.
Direct spinning isused to produce staple yarnsfromfilament fibers.
Conventionalspinning
Basicallyconventionalspinning involves sorting andblending, formationof
web for ease ofhandling, alignment offibers, stretching offiber bundles and
actualspinning offibres into yarns.
Sorting and Blending
Picking
Carding
Drawing
Roving
Spinning
Combing

(1)Sorting and Blending: Thefirst stepinconventionalspinningofstaple
fibers issorting and blending. Balesoffibresare loosenedand fluffed. Impurities
such as dirt and leaves are removed and fibers are blended to product
specifications.
(2) Picking: It is thesecond step in conventionalspinning. The fibers are
formed into web like sheets for ease of handling. These fiber webs are called
laps. The forming ofstaple fibers into laps is called picking.
(3) Carding: Thefiber webisfedinto acarding machine,whichstraightens
the fibers andpartiallyarranges theminto parallelrows. Thealignedfiberwebis
thenformedinto along, untwistedropecalledasliver. Theprocess ofseparating
and aligning thefibers is called carding.
(4) Combing: Whenonlylong, smooth staple fibers aredesired the short
fibers are removed from the slivers in a combing machine. Removal of short
fibers and alignment of the remaining long fibers into parallel rows is called
combing.
(5)As only long fibers are used, combing increases luster and strength.
Thus a fabric composed of yarns than that have been combed will be more
expensive thana fabric composed ofyarns that have onlybeen carded.
(6) The drawing process uses four sets of rollers, each set rotating at
faster rate ofthe previous set severalsliverss are combined and pulled into one
long, thenslivers. Iffurther blendingisdesired, sliverss ofdifferent fibers maybe
combined inthe drawing process.
(7) In roving the drawnsliverss are pulled to approximatelyone fourth of
their originaldiameter and slight twist is added. Hence roving is process that
reduces thesliverss to a sizesuitable for spinning.
(8) There are three systems ofconventionalspinning a) cottonb) woolen
(c) worsted
Theyutilize thesteps previouslydiscussed. Here themachineryis designed
to handle specific type and lengthoffiber involved.
ConventionalSpinning
Cotton Woolen Worsted
eg. cotton, linen eg. wool and fur eg. long fibres
man made fibers fibres and staple with high
length man made degree turst
fibres

Direct spinning
It is used to produce staple yarnsfromman-made filament fibers. It is less
expensive.Inthedirectspinning,weblikestructuresoffilamentfibersarestretched
and brokenat intervals producing long staple fibers. The staplefibers are then
drawn into sliverss. The remaining spinning process is done bythe following
steps.
5.2 Yarns and Classification of yarns
Yarns can be classified based on length of fibres present and number of
parts present.According to the lengthoffibres present in yarn.
Yarn are broadlyclassified as staple/spun, yarns or continuous filament
yarn. Spunyarn consist ofstaple fibre assembled and bound together bytwist
to producetherequired characteristicssuchasstrength, handle andappearance.
5.2.1 SpunYarns
Spunyarnsare made fromthestaple fibres that aretwisted together. Spun
yarnsarecharacterizedbyprotrudingfibreends. Spunyarnsstrengthisdependent
on the cohesive or the clinging power ofthe fibre and on the points ofcontact
Filament fibres stretched
Breaking
Drawing
Roving
Spinning
Spunyarn Filament yarn
Yarn
Smooth Textured
bulk
Napping Average
Twist
Voile
Twist
Crepe
Twist

resulting on pressure ofthe twist. Thegreater the number ofpoints ofcontact,
the greater is the resistance to the fibre slippage withinthe yarn.
Theyare suited to clothing fabric in which absorbency, bulk, warmth or
cotton like or wool like textures is desired. When worn fibre ends hold the
yarns awayfromclose contact fromthe skin, and so fabrics made ofspunyarn
is more comfortableona hot humid daythan a fabric ofsmoothfilament yarns.
Protruding ends contributeto a dullfuzzyappearance, to the sheddingoflit and
to theformationofpills onthe surface ofthefabric. Theyalso get dirted readily,
spun yarncanbe givendifferent types oftwist basedonthe end use as napping
twist.
Napping twist: This type ofyarn is called as low twist, yarn. It has 2.3
turns per inch such low twist results in lofty yarns which allow for napping of
fabric. Thus napped fabrics are bulky and provides warmth when used in
garments.
Average Twist: It is frequentlyused for yarns made ofstaplefibres and is
veryseldomusedfor filament yarns. Theamount oftwist that gives warp yarns
maximumstrengthis referred to asstandard warp twist.
Hard twist (Voile twist): When yarns are given 30-40 turns per inch,
theyarecalled hard/voile twisted yarns. The hardness ofthe yarn results when
twist brings fibres closer together and more compact.
CrepeYears: Crepe yarns aremade ofwitheither stapleor filament fibre.
Crepe is aFrenchword meaning crinkle. Theyare made with ahigh number of
turns per inch(40-80) inserted inyarns. This makes the yarnso livelyand kinky
that thetwist must be set before it canbewovenor knitted filament crepe yarns
are used in fabrics like Georgette and chiffon.
5.2.2 FilamentYarns
The range offilament yarns is as diverse as that ofstaple yarns. Filaments
yarns are divided into two types viz flat continuous filament and textured
continuousfilament yarn.
(a)Continuousfilamentyarnsareprovidedfromlongcontinuousfilaments.
Filaments yarns are primarilyman-made. Silk is the onlynaturalfilament and
accounts for less than 1% of the fibre and yarn production. Regular or
conventional filaments yarns are smooth and silk like as they come from the
spinneret. Their smoothnature gives themmore luster thanspunyarns, but the
luster varies withthe amount ofthedelusturing agent used inthe fibre spinning
solutionand theamount oftwist inthe yarn. Filament yarnshave no protruding

ends, so theydo not shed lint; they resist pilling and fabrics made from them
tend to shed soileasily.
(b) Textured continuous yarn are man-made continuous filament yarns
that are been modified by subsequent processing to introduce crimps, coils,
loops or other distortions into the filament or with high twist or low twist. The
additionoftwist increases bulk texturing gives slipperyfilaments the aesthetic
propertyofspunyarns byalteringthe surface characteristics and creating space
between the fibres. It also improves the thermal and moisture absorption of
filament yarns.
According to the numberofparts inYarns
1. SimpleYarn.
Intheconstructionofsimpleyarn, onlyonekindoffibreisused. Themanner
inwhichthefibres are twistedwillbethesamethroughout the lengthofthe yarn.
Yarns are knownas simple, plyor cable depending uponthenumber ofstrands
theycontain.
2. SingleYarn
Inthis, anumberoffibresaretwistedtogetherinto acontinuouslength. The
yarns consists of one kind offibre. This type ofyarnis the oneusuallyfound in
most standard fabrics for clothing and householduse and purposes.
(a) Single yarn (b) Two ply yarn (c) Cord yarn
Fig. 5.1Types ofYarns
3. Ply yarn
Two or morethantwo single yarnsare twisted together to forma plyyarn.
These yarns areknown as multiple strand yarn. Iftwo single yarns are twisted
together, theresultingyarnisknownastwo-plyyarn. Ifthreearetwistedtogether
three-plyyarnand so-on.

4. Cord/Cable
It is made by a third twisted operation, in which ply yarns are twisted
together. Some types of sewing threads and some ropes belong to this group.
Cords are seldomused in apparelfabric, but used inindustrialweight fabrics.
Fig. 5.2 Parts ofYarn
DoubleYarn
This consists oftwo or more single strands treated as one in the weaving
process, but the strands are not twistedtogether. These areused for ornamental
effect as the low twist yarns produce luster and softness.
5.2.3 Novelty Yarns
The constructionofthese yarns is ofcomplexnature and is varied inmany
ways. These yarnsare usuallyplyyarnsofdifferent kindsoffibresor ofdifferent
colours and are irregular rather thansmooth single strand or yarn ofvarious
colours, sizesoffibres maybetwisted together to formcomplex yarn.Another
varietyisbrought about inthiskind ofyarnbyvarying the tensionorspeed after
intervals ofcertainlength. Thus allowing one part to loop or twist around the
other. Noveltyyarnsarealso constructedfromsimpleyarnbyvaryingtheamount
oftwist. The complextype ofnoveltyyarn is used withtwo objects inview one
is to combine different fibres eg. Cotton and rayon may be blended with or
covered bywoolor silk. This lowersthecost ofproduction. The other objective
is to producea noveltyyarn. Forthe construction ofnoveltyyarns, at least one
Binder
Ground
Effect

or two single yarns are use. One forms the foundationyarn knownas a base or
the core and the other, The effect ofyarn whichis wound or looped round the
first one.Athird yarn called binder yarn is oftenused to fasten or tie the effect
yarn to the foundation yarn. These types ofyarns are mostlyused for drapery,
up hoisteryfabrics.
Fig. 5.3Parts of NoveltyYarn
5.2.4 Types of Novelty Yarns
Slubyarn: This is a yarn made withthick and thin placing byvarying the
amount oftwist in the yarn at regular intervals. Theyare found in draperyand
upholsteryfabrics.
Fig. 5.4 Slub yarn
Flock yarn: These are frequentlycalled as flake yarns. These are usually
single yarns inwhich smallamount offibres either different colours or luster or
bothareinserted into the yarnand held inplace bytwist ofbaseyarn eg: tweed
fabric. This gives a spotted and short streakyappearance.
Fig. 5.5 Flock yarn
Thick and thin yarns: These aresimilar to slubyarns but theseare made
fromfilament like slubprepared fromstaples. The pressure forcingthe spinning
solutionis varied the filament is thick in some places and thin insome.
Fig. 5.6Thick and thin yarn
Core yarn
Boucle yarn
Effect yarn

BoucleYarn: These are characterized by a projecting fromthe body of
the yarnat fairlyregular intervals. Thereare 3 plyyarns. Theeffect yarns forms
irregular waysurface and binder ties it to the base. It has twisted core yarn.
Fig. 5.7 BoucleYarn
Loop and curlyarn, Gimp yarn: Gimp is same as boucle but the effect
yarn isregular semicircular appearance, while in loop.
Snarl yarn or spike yarn: This is made in the same way as loop yarn
using ahighlytwisted effect yarn, whichforms snarls ratherthanloops.
Knop(button)yarn/knot/Nub/Spotyarn:Thisfeatureprominentbunches
ofone or more ofthe component yarn at regular or irregular intervals. This is
madeonaspecialmachine that permitsthe baseyarnto beheldalmost stationary
while the effect yarn is wrapped around it severaltimes to build upon enlarged
segment with brightlycoloured fibres added at the enlarged spot.
Fig. 5.8 Knopyarn
SeedorSplash: Theyresembleknops or knotyarnsbut theknot segments
are tinyinseed yarn and elongated in splash yarn.
Cloud: Atwo colouredyarn, inwhichbothyarns takeinturnto obscure or
cloud the other, giving the appearance ofanintermittent color change.
Spiral or Corkscrew : It is made bytwisting together two plyyarns that
differ insize, type or twist. These two parts maybe delivered to the twister at
different rates ofspeed.
Fig. 5.9 Spiral yarn
Boucle yarn

Chenille Yarn: These create specialeffects chenille means caterpillar in
French. The yarn has a cut pile effect which is bound to the core on the loom
warps are arranged in groups (2-6) which are interlaced in a cross weaving
manner. Weft is inserted in a normal manner. These are cut into wrap way
threads.
Fig. 5.10 ChenilleYarn
MetallicYarn: These are primarilydecorative. The plastic coasting on it
resists tarnishing but care must be takenwhile pressing as puremetals are soft,
their thinfilms are used overa core yarnthat has replaced gold and slivers now.
There are two methods ofpressing.
Yarn twist: Twist isthe spiralarrangement ofthe fibres around theaxis of
theyarn.Revolvingoneendofthefibrestrandwhiletheotherendisheldstationary
produces twist.Twist binds the fibrestogether and gives thespunyarnstrength.
It isa wayto varythe appearance offabrics. The number oftwistsis referred to
as turns per inch. Theyhave a direct bearing onthe cost.
Twist is the spiralarrangement of the fibres around the axis of the yarn.
Revolving one endofthe fibre strand while the other end is held stationaryany
produces twist. Twist binds the fibres together and to gives the yarn. Higher
twist whichyields lower productivity.
Fig. 5.11Yarn twist
Direction of Twist
The direction of twist is described as s-twist and z-twist. Ayarn has S-
twist ifwhenheld ina verticalposition, the spiralconfirmthedirection ofslope

of the centralportion of the letter “Z”. Z-twist is the standard twist used for
weaving yarns. The majorityofsingleyarns are spunwithtwist in Z-direction.
TheAmount ofTwist varies with
1. The lengthoffibres
2. The size ofthe yarn
3. The intended use
5.2.5 Yarn count
Yarnnumber variesand it differsaccordingto the kind offibre. Manyyarns
are used for weaving and sewing threads are numbered bythe cotton system.
Spunyarnsize is referred to as count and isexpressed interms oflengthper unit
ofweight. It is anindirect system. The finer theyarn, the larger thenumber. The
count is basedonthe number ofhanks (1 hank is840 yards) in1pound ofyarn.
Inthissystemthe unit ofweight remains constant.
Count = length/ one pound.
Count = No of hanks x 840 yards / one pound.
Denier: Filament yarnsize is dependentlypart on the size ofthe holes in
the spinneret and partlyonthe rateat whichthe solutionispumped throughthe
spinneret and rate at whichit is withdrawn.
The sizeofthe filament yarns isdetermined as denier, whichis expressed in
terms ofweight per unit length. If9000 meters ofyarnweigh 1 gmit is then 1
denier. Inthissystem, the unit oflengthremains constant. The finertheyarn, the
smaller the number.
Denier = weight ofyarns ingms/9000 mts.
1 denier = 9000 mts weigh 1gm
Texsystem:The internationalorganizationforstandardizationhasadopted
theTexsystem, whichdetermines the yarncount or number inthesame wayfor
allfibre yarns and uses metric units.
Tex= weight in gms/100 mts ofyarn.
Conclusion
Therearedifferent typesofyarn.Eachhavingtheowncharacteristics. These
characteristics varyaccordingto the constructionand the treatment giveninthe
manufacture ofthe yarn. Yarns playa very important role in determining the
hand and performanceofthefabric.Yarnis the generic namefor the assemblage

offibres that is laid downortwisted together. Thus yarns playanimportant role
inthetextileindustry.
1. The threetypes ofspinning are wet, dryand melt spinning in chemical
spinning.
2. Dryspinning is used to make polyester.
3. The construction ofspinneret decides the diameter ofthefiber and the
type offibrei.e. mono filament and multifilament depending onnumber
ofholes.
4. Conventionalspinningutilizes the steps discussed for (a) Cotton
(b) Wool (c) Worsted fibers too.
5. Direct spinning is used to produce staple yarns fromnaturalfibres.
State whether thefollowing statement areTrue/False
1. The warp yarn needs a greater amount oftwist to produce strong firm
thread (T/F).
2. Spunyarnconsists offilament fibres (T/F).
3. Napping can done to low-twist yarns. (T/F).
4. Crepe is French word meaning crinckle (T/F).
5. In simple yarn one kind offibre is used. (T/F).
6. Whentwo or more thantwo single yarns are twisted together,it is called
cable (T/F).
III. Test your understanding
State whether thefollowing statements areTrue/False
1. Noveltyyarnsare mostlyused for upholstery, drapery. (T/F)
2. Twist isthe spiralarrangement offibres around the axis ofthe yarn.
(T/F)
3. The direction ofthe twist is described as X-twist andY-twist. (T/F)
4. The count is based on number ofhanks in 1 pound of yarn. (T/F)

5. Denier –Weight ofyarns ingms/1000 mts (T/F).
1. What is yarn?
2. What are spun yarn.
3. Write about continuous filament yarns.
4. Write about noveltyyarns.
5. What is yarn twist.
6. What is yarn count?
7. Write about tex system.
1. Write the classification ofyarns.
2. What is filament yarn?Write about textured continuous yarns.
3. What are noveltyyarn?Write anyfour types ofnoveltyyarns.
Answers for test your understanding - I
(1)True
(2) False (acetate)
(3)True
(4)True
(5) False (man-made fibres)
Answers for test your understanding - II
1. True
2. False – Staple fibres
3. True
4. True
5. True
6. False – Ply yarn

Answers for test your understanding - III
1. True
2. True
3. False – S & Z twists
4. True
5. False – 9000 mts.
4. Write indetailabout yarntwist.

Structure
6.0Introduction
6.1 Weaving
6.2Knitting
6.3 NonWoven fabrics
Learning Objectives
• Understand what is weaving
• Understand the generalcategories ofnonwovens a) durable b)
disposables
• Explainthesemidurable wovens.
• Know about a)Weft knitting b)Warp knitting
• Classificationofweft knit fabrics
• Design inweft knit fabrics
• Identificationofwarp knits.
Fabric Construction Methods
6UNIT

Unit Preview
Thisunit givesus theinformationregarding thefabricconstructionmethods
such as
(a) Weaving
(b) Knitting
(c) Non woven fabrics.
6.0 Introduction
Fabrics are producedmostlyfromyarns. Few fabricsare directlyproduced
from fibers. In Indian market 70% of the fabrics are produced by weaving.
Amongtheotherfabricsthat isnonwovenfabricslacemakingisworthmentioning
along withneedle punched and tufted fabrics. Felts are fabrics made directly
fromfibers without making yarns where fusible use is mostlyemerging now a
day.
The fabric construction process determines the appearance and texture
the performance during use and care and cost of fabrics. The process often
determines the name ofthe fabric for eg: felt lace, double knitt and jersey. The
cost offabrics inrelation to the constructionprocess dependsuponthe number
of steps involved and the speed ofprocess, the fewer the steps the faster the
process, the cheaper is the fabric.
The fabric constructionmethods include weaving, knittingand nonwoven
fabrics.
6.1 Weaving
Yarn isturned into fabricsofgarments byweaving, knitting, or felting.
Fabrics are woveninlong lengths from40 to 100 or moreyards and from
about 20 to 60 inches in width. For a fabric to have strength and compactness
combined with a fair degree ofelasticity, the warp and filling threads must be
interlaced. This interlacing is called weavingand it is doneona loom.
An interlacing where the filling threads are passed alternatively over and
under thewarp threads is calledas a plainweave. It is the simplest ofallweaves.
Ifthe fillingsthreads are passedoneover and2 under ormore warp threads
willresult intwillfabrics.Thesurfaceofsuchfabrichaspatternofparalleldiagonal
ridges.

Ifthe warp threads or filling threads are considerablythicker then the rib-
weave is produced.
Thus the verylarge number of variations of methods for interlacing the
warp and filling threads makes to weave the wide variety of fabrics each of
which has specialproperties and uses.
The beam of the warp threads is placed at the back of the loom and the
threads are drawn from it across the loomfromback to front to be wound on
another roller. Forthe weaving ofplaincloth, the threads aredrawnthroughthe
eyes oftwo sets ofheddles.
The filling threads pass over and under alternate warp threads which are
lifted and loweredbythe corresponding heddles.
Toe cop with the filling threads is placed in a shuttle which is moved or
thrownfromside to sideacrossthe loom. Eachpassoftheshuttle laysonefilling
threads. Thecomblike reed describedearlierbeatsthefillingthreadstight against
thepreceedingfillthreads, asthefabricis wovenitis slowlywoundonto a roller
infront ofthe loom.
The following listsincludes some ofthemost commonweaves:
1. Plain weave (a) Rib weaves (b) Basket weave
2. Floating weave (a) Twillweave (b) Satin weave (c) Sateen weave.
And its variations
6.2 Knitting
The knittingsindustryisa uniqueanddistinct part ofthetextileindustry. It is
the second important method of making fabrics after weaving. The knit
characteristics are
• Bulkywithsurface effect.
• Looselyknittedor tightlyknitted.
• Rib-purl-tricot.
Circularknit:Anyfabric produced on acircular knitting machine.
Double knit:Aspecialtype ofribknit fabric usuallyclosedstitched witha
pattern or design effect, generallythicker, heavier and more stable than jersey.

Difference betweenWeaving and Knitting
Weaving and knitting are the two most common process ofmaking cloth.
Weaving is the process of interlacing two sets of yarn at right angles. This
operation is done either on a hand or a power loom. Ifone set of yarns form
loops one loop caught into another and one row ofloops hanging on the one
below. The cloth is made byknitting.Of these two processes, Weaving is the
most common method although new and improved knitting machines make
clothquicklysatisfactoryand the attractive patterns.
Wales (in knitting’s): Aseriesofloops insuccessive rowslyinglengththe
wise ofthe fabric.
Purl: Purlis actuallythe opposite ofknit.
Fig. 6.1 Plain stich and purl stitch
Course: Aseries ofstitches or loops that run cross wise is knitted fabric,
corresponds to the fillings inwovengoods.
Stitch:Asingle loop or turnofthread oryarnmade byhandor machine in
sewing crocheting, tatting , lace making,knittingand knotting.
Jersey: Describes any knitted fabrics where in all of the stitches on one
side ofthe fabric are knit stitches, while allstitchesonthe reverse sideare either
purlstitches or a combination ofpurltuck and /or miss stitches also known as
singlestitches.
The knitting industryhas two mainbranches
(a) The knitted yarnsgoods industry : Whichproduces thefabric sold
to apparelmanufactures, sewing centre retailshops and others.

(b) The knitted end produces products industry: Which produces
completed consumer products such as hosiery, sweaters, men’s T shirts and
athletic shirtsand others.
Weft knitting: Knits are classified as a) warp knits b) Weft knits.
It is a type of knitting in which yarns run horizontally from side to side
across the widthofthe fabrics.
The fabricis actuallyformed bymanipulating the knitting needlesto make
the loops in horizontal courses built one on top of another. All stitches in a
course are made byone yarn. It is simplest form;a weft knit canbe made from
one yarn.
Weft knits are made either flat or open width fabrics (like woven fabrics)
onso calledflat knitting machines.
Fig. 6.2 Simple warpknit fabric
Warp knitting:Warp knitting’sinvolvesthe preparationand useofa warp
beamcontaining averylarge number ofparallelyarns mounted on the knitting
machine. In warp knit fabrics the yarn run the length of the fabrics. The yarn
forms the verticalloop in the one course and theymove diagonallyto the next
wale to make a loop inthe following coarses. Theyarnzigzag fromsideto side
along thelengthofthe fabrics. Eachstitch ina coarse is made bydifferent yarn.
Knit fabrics names: Classical knit fabrics are named primarily on the
basis oftheir constructionnot onthe basis ofappearance and weight.
Identification ofwarp knits
Practicallyallthe warp knittedfabrics are identifiedanddistinguishedfrom
weft knitted materialsbycarefulobservation ofthe face and backofthe fabric

usually with the aid of a pick glass. The face of the fabric has rather clearly
defined plainstitches. Generallyrunning verticallybut slightlyangled fromside
to side. The back of the fabric has slightlyangled but horizontal floats. These
floats are called ‘laps or under laps’ formed fromthe side ways movement of
the warp yarns as the fabric is made, the recognition oflaps ina knitted fabric
isthemost important distinguishing feature.
6.3 Non woven fabrics
Non wovenfabrics are made bythe anyprocess otherthanweaving. They
are defined as textile materials made directlyfrom fibers and held together as
fabrics bydifferent methods. The firstnonwovenwasintroducedin1942. There
are two generallycategories ofnon woven’s 1. Durable 2. Disposable.
Durable: The materials are not manufactured or intended to be thrown
awayafterthesingleorlimitednumberofapplications. Examplesincludeapparel
interlining, carpet backings etc.
Disposable: these materials are manufactured with the intention ofbeing
thrownawayafterthesingle orlimitednumberofapplications. Examplesinclude
disposable diapers, head rests, surgicalgowns, filters etc.
Semi durable non wovens: Some items might be considered as semi
durable like handwipes. The major fiber used innonwovensfor the disposable
is rayonwhilethe major fibersfor durables include rayon, polyster, olefinothers
used are nylon, vinyl, acrylic, cottonforcreating non woven’s a weboffibers is
first made. This means that fibers are laid by machines in random manner to
form this layer called web. Later these webs are laid over each other and are
then hold in place by
- Needle punching
- Bonding bymeans ofadhesive heat.
Needle punching is a mechanicalprocess which enlarges the fibers in the
web bypunchingthemwithneedles. Thisis the most inexpensive method such
non wovenare used infloorcovering in filters.
Bonding is a method where 2 or 3 more layers offiber webs are made to
stick to each other by adhesives. These are used in disposable items such as
protective gowns, hats etc.
Bonding bymeansofheat canbedone whenthe fibre webscontainat least
30% fibers. Since these synthetics soften by heat, heat is applied so that the

fibers bond with each others forming a non woven. These non woven provide
shape to cut parts ofgarments. So this webs can be used ad interlinings.
Felting
Woolis aprobablymost idealforfeltingbecausethefibersswellinmoisture,
interlock andremainin the conditionwhenpressed and shrunkwhen the fibers
have been selected and if necessaryblended with cotton or man made fibers
theyare caredinto a flat sheet or bat. Bats areplaced first one wayand thenthe
other layers untilthe desired thicknessisreached.Allowance has to be made for
shrinkage because steam and pressure of heavy pressures in the process of
felting mayincreasethe bats as muchas 20% thickness. To makethe felt fabric
stronger and morecompact the fabrics is placed inwarmsoapywater where it
is pounded and twisted. For heavy felt a weal acid is used instead of warm
soapywater.The clothis thenreadyfor finishing processconsistingofscouring,
dyeingpossiblypressingorshearingandtreatment withspecialfunctionalfinishes
to make it water repellent mothproofand shrinks create andfine resistant. Felt
is made for men and a women’s hat’s, women’s skirts, rests and slipper tables
covers. Paddlingandlining’s wovenfeltshavetheirplaceprimarilyintheindustrial
field.
Nets and braids
Net in geometrically shaped figured mesh fabric made of silk, cotton ,
nylon, polyester, rayonand other man made fiber. It comes indifferent sizes of
mesh and in various weights. On the other hand machine made net is closely
related to warp knitting because it is constructed on either a tricot or Rachel
warp knitting machine. The first nets to be made by machine were the warp
knitted tricot that appears about the middle ofthe 18th century.
Another type of net in the knotted square mesh type with knots with 4
corners to formthe mesh. Originallymade byhand and used byfisherman it is
now made by machine. These modernfish nets of linen cotton byman made
fibers are used for glass curtaining in contemporaryliving rooms, sun porches
and dens.
Braids
This is a method of interlacing 3 or more yarns or bias cut strips of cloth
over andunderone anotherto forma flat ortabularfabric. Thesebraidedtextiles
bands whicharerelativelynarrow can be used as belts, pullcards for lights and
for trimming for uniforms and dress tapes for pajamas’ and some shoe laces.
Severalwidth ofplastic and straw braidingcan be sewentogether to make hat

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