Kiến Thức Hàng May Mặc cho Công Tác Quản Lý Đơn Hàng Ngành May - Understanding textiles for a merchandiser

___08 Understanding Textiles for A Merchandiser___ Số trang: 653 trang Ngôn ngữ: English -------------------- Contains: Textile Fibre Yarn And Yarn Manufacturing Weaving Technology Fabric Structure And Design Special Woven Fabric Production Warp And Weft Knitting Technology Knitted Fabric Technology Special Knit Fabric Production Sweater Knitting Dyeing Printing And Finishing ---------------------- Description: This book is one of the versatile books for textile study for students and professionals who wants to gather all basic principles of textile product processes and engineering methods applied in this field. From fiber to finishing of products, all the methods and strategies are described in this book. This book also followed by textile schools, collages, institutes and universities of Bangladesh for their academic curriculum. This book has become the most popular book for textile learners in Bangladesh. -------- CODE08.653.GS.150

N o R

Teytie f ib res; Ya rn a n d b'z rn m a uf a ctu ring;

W eaving technology; Fabric structure and design; Specia I w oven fabric production;

W eft and w arp knitting technology; Knitted f abric design; Specia l knit fabric production;

Sw e ate r k n itt in g;

Dyeing, printing and finishing

Engr Shah Al imuzzaman Belal G ext ATI (U K.)

Assistant ProfessorCollege of Textile Engineering and Technology

Dhaka, Bangladesh

3 f dationPublished by BM N ounDhaka, Bangladesh

Properties of textile fibres

Prim ary properties of textile fibresSecondary properties of textile fibres

Classification of textile fibres

Fibre identification

Burning test

Light m icroscopy test

Chemical solubility test

Types of fibres

Classification of yarn

Types of cotton yarnBlowroom section

Process Iayout of the yarn m anufacturing system

w ith a modern blowroom IineCarding section

Doubling and draw ing

Com bing sectionSimplex or Roving fram eCotton spinning system

Sp in in g mach ineAutoconer

Yarn conditioning and packingDefinition

Types of yarn count

Calculations concerning count

Form ulae for count conversion

Count calculation and denotion for pIy yarnLength calculation of a cone of sew ing thread

Yarn and

02402502803003003203403536039040041041041

Yarn num bering system

044046O47050051051051051052

W oven fabrics and

W eaving technology

Fabric classifitation at a glanee

W oven fabriesProeess flow to manufaduring woven fabric

W eaving preparation

W inding

W inding processTension deviceTypes of packages

Pirn winding

W inding machinePrecision w indingProblem

W arp preparation

W arping

Direct or High speed w arping

Indirect or Section warping

W arping m achineSizing or Slashing

Sizing m achineDraw ing-in and Tying-inFundamentals of weaving

W eaving principle

Basic w eaving m oti ons

W arp Iet-off

W arp shedding

W eft insertion or pickingYarn accum ulators or feedersBeat-up

Take-upAuxiliary w eaving m otionsFabric width

W eaving m achine or LoomShuttle w eaving m achinesShuttleless weaving m achines

Projectile weaving machine

Rapier weaving machine

Ai rjet weavi ng machine Water-j et weavi ng machi ne

M ultiphase weaving m achineFabric selvages

Grey fabric inspection Iines

055056057

057

057058059

063

069

071

072072

073 074 074

076

077 079

083086

089

093093095

095

096096

098

100

102 103

103105

106

107108

110

111113

114 115 117

Fabric structure

and design lntrodurti on to fabri c strueture and desi gn

W oven fabric specificationFabric weight calculationYarn consum ption calculationParts of a complete design

Drafting

System or classification of draftingBasic weaves of w oven fabricPlain w eave

118 119

121

121 123 125

129131

134

135

135

136137

165

167168

173 175

179183186187188

189

194195

201 202 205

205

209 211

217220227

M ain features of plain w eave

Classification of plain c10thDerivatives of plain w eaveRib w eave

M att w eaveOrnam entation of plain (10th

Tw illw eave

Classification of twill weaveDerivatives of tw ill w eave

Zig-zag tw ill weaveHerringbone tw ill w eave

Diamond design

Diaper designBroken tw ill w eaveRe-arranged tw ill w eaveStepped tw ill weave

Elongated tw ill weaveCom bined twill weaveShaded twill weaveAdvantages and disadvantages of twillSatin w eave

Classification of satin weaveConstrud ion principle of satin weaveDerivatives of satin weave

Crepe w eavesCorkscrew w eavesShaded weavesFancy design or structure of fabrits

Com pound colour and w eave effects

Figuring w ith extra threadsCom pound fabrics

Tubular c10thDouble w idth c10th

M ulti-ply fabricsStitched double cloths

Classification of double c10thSelection of suitable stitching positionsConstruction principle

Self stitch double c10th

W added double c10thCentre stitch double c10thFabric used in apparel sector

Fabric based on plain w eaveFabric based on tw ill w eaveOther com m ercial fabricsFabric construction or specification

spetial fabrit produd ion

2 7 1

W eavi ng pri nci pl e and end uses 278

Features and raw m ateri ai s of denim fabri c 283

The doubIe-cloth or face-to-face m ethod 295

The sl ack tensi on pil e or terry w eave 305

Kni tted fabrics and

Kni tting technology Introducti on and histori cal background of knitting

General term s related to knitting technology

M echanical principles of knitting technology

Basic elem ents of knitting

Th e n e ed 1e s

Th e ca m s

The sinkers

M ethods of yarn feeding

M ethods of form ing yarn into needle IoopsStitch form ation on bearded needlesLoop form ation on Iatch needlesKnitting action of com pound needles 351

M ain features of a knitting m achine 354

Classification of w eft knitting m achines 354

Flat knitting m achine 356

Circular knitting m achine 358

Fa b ric m a ch in 36 1Garm ent-length m achines 362

Single-jersey circular knitting m achine 363

Rib circular knitting m achine 369Interlock circular knitting m achine 377

Links-links or Purl knitting m achine 380Basic w eft knitted structures 383

The plain knit structure or plain fabric 383The rib structure or rib fabric 385The purl knit structure or purl fabric 389The interlock structure or interlock fabric 392Com parison between basic structures 394

Identification of single and double jersey 395

Basic Ioop or stitch types 396

The float stitch or Ioop 398The tuck Ioop or stitch 403The drop or press-off stitch 411Designs of w eft knitted fabrics 413

Ornamentation of single-jersey fabric 413

Double-jersey derivatives based on rib 421

Derivatives of interlock structure 427

W eft knitted jacquard design 437

Single-jersey jacquard design 437Doubl e-jersey jacquard design 441

322 326 337

337

337 341 344 345 346 347 349

Sw eater knitting 446 )

tFeatures of the sweater knitting m achine 447 t

The manual sweater knitting machine 448 t

.

< 4

Production of different fabrics on sweater t

Sti tch or l oop transfer in weft kni tting 461 j

i

r'

Shaping or fashioning frequencies calculation 487

Calculation related to w eft knitting 501

Knitting speed and machine rpm 502

Speed factor or pedormance number 503

Production calculation 504

W eight per unit area and cover factor 5O9

Relation beto yarn count & m achine gauge 511

Relation between yarn count and GSM 512

lntroduction to warp knitted fabrics 514

Lapping diagrams and chain notations 522

Basic stitches in warp knitting 523

Tricot w arp knitting m achine 531

Raschel warp knitting machine 538

Two fully threaded guide bar structures or fabrics 546

Spetial knit fabric production 553

Fleece knit fabric 553

High pile knit fabrics or sliver knit fabrics 555

Plush fabrics or knitted terry fabrics 557The crochet warp knitting m achine 559

The straight bar frame 563

Netting or net fabricsLace fabrics

aw m aterials

W eb form ation

W eb bondingFinishingCharacteristics and uses of nonw oven fabricsSpecialty nonw oven products

Preparatory process or pre-dyeing treatm ents

Singeing

Desizing and Scouring

Bleaching

M ercerizingHeat setting

Elastic fabric

W ashingDryingDyeing

568570579579580583588589590591592593594595596598599600

Textile dyeing, printing

and finishing

605612613615619621622623624627

Preparation and dyeing m achineryAutoclaves

W inch dyeing m achine

Grateful acknowledgements are made to m any of my friends, colleagues and dear studentswho have relentlessly encouraged me to write this kind of a book and read different chapter ofthis book, given encouragement and very helpful criticism

Specially, I would Iike to show a huge appreciation to my beloved wife Sumona and m y Iittlegirls Hafsa, Sumaia and Eusha W ithout their support and patience l would never have beenable to finish this work

The word ''textile'' originally applied only to woven fabrics, now generally applied to fibres,yarns, or fabrics or products m ade of fibres, yarns or fabrics. The term textile originatesfrom the Iatin verb texere - to weave - but, as the Textile Institute's Term s and DefinitionsGlossary explains, it is now /'a general term applied to any manufacture from fibres

,

filam ents or yarns characterized by flexibility, fineness and high ratio of Iength tothickness''

Textiles, especially fabric is the fundam ental com ponent of a readym ade garm ent,because

it is the basic raw m aterial of a garm ent.So it is im portant to know the m anufacturingsequence of fabric from fibre The quality product is the m ain goal at present tim e,W ithoutknowledge of Textile manufacturing i.e fibre, yarn and fabrics it is im possible to m aintainthe quality of a garment Before elaborating on whole process of grey fabric m anufacturing

let us look on what is textile fibre, yarn and fabric and what are the process flow chart ofTextile M anufacturing can be described

Textile:

A term originally appbied only to w oven fabrics, but the term s textile and the pluraltextiles are now also applied to fibres, filaments and yarns, natural and m anufactured,and m ost products for w hich these are a principal raw m ateriai.

be m ade; and qualities such as w arm th, resiliency, softness, and durability required in

the fabric's end uses

@ Fabrk:

Fabric is a ffexible pdanar substance construded from solutions, fibres, yarns, or fabrics,

in any combination Textile fabrics can be produced directqy from webs of fibres bybonding, fusing or interlocking to make non-woven fabrics and felts, but their physicalproperties tend to restrict their potential end-usage The mechanical manipulation ofyarn into fabric is the most versatile method of manufacturing textile fabrics for a widerange of end-uses

FIoW chart of textil e processing:

l nput / Raw materi al s

Yarn

Fabric Manufacturing(Weaving / Kni tting I ndustry)

TEXTILE FIBRES

Any substance, natural or m anufactured, w ith a high Iength to w idth ratio and with suitablecharacteristics for being processed into fabric; the sm allest com ponent, hair Iike in nature,that can be separated from a fabric

Properties of Textile Fibres:

Prim ary properties of textile fibres:

High Iength to w idth ratio

Tenacity

FlexibilitySpinni ng quali ty (Cohesi veness)Uniform ity

Setondary properties of textile fibres:

considerably greater than the diam eter The length is

t Natural fibres, except for silk, are m ostly som e m illimeters

Iength) and the I ength must be

a vew im portant fibre property.u' to severalp centim eters Iong

or are chopped into (shorter)

w- j uj j

Flexibility is the property of bending without breaking that is the third necessawcharacteristic of textile fibre In order to form yarns or fabrics that can be creased, that havethe quality of drapability and the ability to m ove with the body and that perm it generalfreedom of m ovem ent, the fibres m ust be bendable, pliable or flexible The degreq of

flexibility determ ines the ease with which fibres, yarns and fabrics will bend and is

im portant in fabric durability and general perform ance

Spi nninz qual i W (fnh- WR* Q):

This charaderistic refers to the ability of the fibre to stick together in yarn m anufaduringprocesses Cohesiveness indicates that fibres tend to hold together during yarn

m anufacturing as a result of the longitudinal contour of the fibre or the cross-section shapethat enables the fibre to fit together and entangle sufficiently to adhere to one another-Un' i * :

To m inim ize the irregularity in the final yarn, it is im portant that the'fibres be som ew hat

si m i l ar in length and wi dth i.e be uni form The inherent vari abil i t' y in the natural tibre can

be averaged out by blending natural fibres from m any different batches in order to produce

yarn that are uniform

W onzaa - 'e oftoe lle & -' ':

* 0 1 0 1 shaN ( sne *n* * a ' ap- o- ):

The fibre shapes i.e the sudace struclure is im portant for the fibre behaviour in a yarn and

in a fabric A rough scaly sudace of w ool fibres, for exam ple, ihfluences the feltingrandshrinkage properties of wool fabrics The scales enable fibres to grip one another w he'n a

yarn is spun

The smooth, glassy sudace of a fibre such as the nylon fibre, affed s the lustre of the fibre-A

sm ooth sudace will not cling to dirt so readily The cross-sectional shape of a fibreinfluences the behaviour of the fabri c A circul ar or near-circul ar cross-secti on (wool ) gi ves

an attradi ve or comfortabl e feel as compared to a fl at, ri bbon-l ike cross-secti on Circular fibres often have a poorer covering-power than the flatter or triangular ones: A flat

lèottonl-or tri angular cross-secti on gives more I ustre Serrated or indented cross-secti o/s ( vi scose)

give better colour absorption as a result of the Iarger area M ore colour is also needed inthe case of fine filam ents The latter also give a softer handle or feel :

A fibre, which is subjed ed to a force, will stretch to a certain degree- This stretching can also be

expressed as a percentage of the original fibre lenglh, w hich is the elongation-The elongatio: of

W hen a fi bre i s subjeded to a small force (or stretched to a smal l degree), i t may exhibi talmost pedect elasticity Elasticity is the property of a fibre to recover its original lengthafter stretching caused by a Ioad

The term breaking elongation refers to the amount of stretch that occurs to the pointwhere the fibre breaks Elastic Recovery designates the percentage of return from

elongation or stretch toward the original Iength or m easurement If a fibre returns to itsoriginal length from a specified am ount of attenuation, it is said to have 100% elasticrecovew at X% elongation

Flam m ability and other therm al read ions:

Burning characteristics of the fibres are im portant in determ ining care and use, and theyserve as helpful guidelines in the fibre identification Federal Iegislation on textile

inflam m ability is an im portant consum er issue and a variety of types of textile end-use

products m ust m eet a specified resistance to flam es

AII fibres are affected in one-w ay or another as they are heated Som e, Iike wool, begin todecom pose before melting; others, Iike polyethylene or acetate will soften and m elt beforedecom position sets in The behaviour of fibres on heating and their ignition properties are

of great practical im portance Indeed, fabrics should withstand the temperatures used inironing, l aundering (wi th water or sol vent) etc Since syntheti c fibres are thermopl astic substances ( i e they wi l soften as they ar e heated) , thi s sof teni ng wi l I argel y determi netheir practical usefulness

In the presence of air, m ost fibres will burn ln this context, the term LOI is used It stands forLim iting Oxygen Index The higher the value of LOI, the more difficult a substance will ignitesince LOI is a m easure of the am ount of oxygen w hich has to be present in the air to let asubstance (conti nue to) burn On average, most stlbstances have an LOI of about 20 Efforts are

m ade to reduce the flamm ability of textile m aterials in order to Iim it accidents.These efforts are

The staple Iength of natural fibres is not an easy property to define because the fibre Iength

can vary over a great area A statistical interpretation of the data obtained on fibre length in

a I aboratory, makes i t possi ble to determi ne the stapl e I ength (an average l ength) ln order

for a fibre to be spinnable, i.e to be twistable, and therefore offer sufficient cohesion to the

whole, a fibre m ust at least have a Iength of 5 to 15 m illim etres Fibres which are Ionger

than 150 m illim etres require specialized spinning m achines which m ake the spinning

p

The most com mon natural fi bres have a ratio I englh / thi ckness whi ch equals one thousand

or several thousands (cotton: 1500, ' wool: 3000; flax: 1200) Coarser fibres such as jute and

sisal have ratios between 100 and 1000 W hen filam ents of m an-m ade fibres are chopped

into shorter fibres, an effort is m ade to bring the ratios close to those of natural fibres, i.e

between 1000 and 4000

T *

Second necessaw property for a product to qualify for textile fibre is adequate strength,termed as tenacity Tenacity is defined as the tensile stress expressed as force per unitIinear density of the unstrained specim en

The strength of a fibre is generally dependent on the length of the polymer chain, the

degree of orientation of these polym er chains, the strength and types of the forces of

attraction between the polymer chains (i nterpol ymer forces) The I onger a pol ymer chai n i s,

the higher the degrees of orientation and crystallization and, hence, the stronger theinterpolym er forces Crystalline system s feel stiff and present less resistance to repeated

bending or folding Stronger fibres will Iead to stronger yarns under the appropriate

Tenacity is expressed in term s of (centilnewtons per tex (cN/tex or N/tex)

l t is i m portant to note that the fi bre strength does not alw ays i ndi cate com parabl e yarn or fabric strength Fi bres w i th high strength are useful in seer and I i ghtw ei ght fabrics Fabri cs used in w ork cl oths and various i ndustrial appli cations are better from hi gh tenaci ty fi bres Fibre tenaci ty does not al w ays reflect the actual strength of textil e yarn It is possibl e for yarns to be m ade so that fibre sl ippage occurs; thi s does not m ake optim um use of the actual fibre tenaci ty.

using substances which sfow dow n or resist burning.

Chem ically speaking, vegetable fibres have aim ost identical com position, and consist ofcellulose, which is a com bination of carbon, hydrogen and oxygen They aIl burn as paper orwood, ignite readily, Ieave Iittle or no ashes and release a distinctive fire smell of burntPaper

Fibres of anim al origin also have a sim ilar chem ical com position; they aII contain nitrogenand will therefore not easily burn through They shrivel and form charred ashes They Ieave

a fire smell of burnt feathers

Exceptions are wei ghted natural sil k (I eaves ashes which keep the form of the yarn) andacetate w here introducing acetate groups in the polym er chains m akes the fibre meltbefore it can ignite

M an-m ade fibres based on protein burn as fibres of anim al origin Fully synthetic fibres m elt

without ignition

Density:

Fibres with different densities but of equal diam eter will have different covering pow er that

is the ability to cover a surface Fabrics made w ith fibres of different densities will have

difference in fabric appearance, flexibility, air perm eability and cover

The density, also called volum ic m ass or m ass density, is the mass per unit volum e and has p

as its sym bol It is usually expressed in grams per cubic centim eter Another term is specificgravity, w hich is the ratio of the m ass of a fibre m aterial and the m ass of an equal volum e of

3 The speci fi c gr avi ty of a substance vi s-à- vi s water equal s the wat er ( densi ty lg/cm )

3

numeri cal val ue of the ( absol ute) densi t y of thi s substance i i t i s expressed i n g/cm Ever y

fibre is characterized by its density, w hich can be m easured in various ways

M easurem ent of density can be carried out with a gradient colum n, where the Iiquid in thetube has a density which varies in height If a fibre is dropped in the tube, it w ill sink to thepoint at which the fibre density equals the Iiquid density, and remain suspended there

This experim ent is based on the fact that a fibre which is subm erged in a Iiquid with thesam e density will sink nor drift but float, and that the density of a Iiquid can easily bemeasured Treatm ents for finishing fibres, can influence the results Foreign substances on

or in the fibres m ust be rem oved before doing the experim ent

The Iist below gives an overview of the m ost im portant fibres and their densities.

Textil e Fi bres Fibre densi ti es in g/cm3 Commerci al name

Polyvinyl alcohol 1.30 Kuralon, vinal

Lusture:

lt refers to the gloss, sheen or shine that a fibre has It is the result of the amount of Iight

reflected by a fibre, and it determ ines the fibre's natural brightness or dullness.

Colour:

Natural colour of fibres vary from pure w hite to deep gray tan or black M an-m ade fibres

are usually white or off-white as they are produced

M oisture regain or effed of m oisture:

AIl fibres tend to absorb m oisture when in contact w ith the atmosphere The am ount

absorbed depends on the relative hum idity of the air

For absorption of m oisture of a fibre, the term regain is used This is the am ount of

m oisture present in a textile m aterial expressed as the percentage of the oven-dry weight

(dry wei ght) of the textil e Thi s dry mass i s the constant wei ght of textil e obtai ned after

OC to 1100c If B is the dry weight and A is the conditionëddrying at a tem perature of 105 .

wei ght (the wei ght after being in a normali zed atmosphere of 20 C and 65% re a humi dity), the regain expressed i n percentage wi ll be:

is moisture content and, expressed in percentage, is:

circumstances The moisture content is alw ays Iower than the regain.

Fibres can present great variations in the amount of m oisture they w ill absorb.W ool has a

regai n of 16% cotton of 8.5%, acetate onl y of 6% Fibres, whi ch can absorb suffi ci ent moi sture,

t itable for processing into clothing because' they will absorb perspiration from theare mos su

body and will hold considerable amounts of m oisture w ithout feeling clam my.The ability of afibre to a bsorb moisture will also affect the processing and finishing of fibres.Fibres which easilyabsorb moisture, will therefore Iet dyestuffs penetrate more easily during the dyeing process.Synthetic fibres, which often absorb little moisture, are easily washed and dried by comparison

with fibres, which absorb a lot of m oisture On the other hand, this entails the phenom enon of

electrostatic charging

The strength of a fibre is affected significantly by the w ater it absorbs.Fibres, w hich easilyabsorb moistu re, wil l usual l y be Iess strong when wet ( except for fl ax an cotton) and wil l presentincreased elongation at break One should also realize that absorption of m oisture can also

m ake the fibre sw ell to a considerable degree, w hich is im portant for fixating dyestuffs.

NM URAL FIBER:

*.ew

tA

' & * r Y< j l * '

a w v

y * *. - ij PX * * > * e* * '

Elassification of Textile Fibres:

Textile Fibres

Natural Fibres

Animal fibre Vegetable fibre M ineral Synthetic bre Regenerated Other

Protei n) (cell ul ose) fibre ( Ynt heti c pol ymer ) fi bre ( carbon,gl ass , metal , (

c er ami c, et c )Asbestos) t nat ur al pol ymer)

(

Silk W ool Hair Alginate Rubber Regen Regen Cellulose(sheep) (alpaca,camel,cow,goat, (elastodi erated e r3ted ester

horse, rabbitet) ene) protein cellulo

(azlon) -se

(ra on)

Ani mal (casei n) Vegetabl e

Acetate Triacetate

Seed fibre Bast fibre Leaf fibre Vi

scose Cupro Modal Lyocell

(cotton coi # r) t fl ax- hemp-jut e, ami e, ( auaca, si sal

Pol ymethyl Pol yol efi n Pol yvi nyl Pol yure Pol yami de Pol yimi de Arami d Pol yester Syntheti c

C f the study of textil e sci ence

At one time,

i The identification of textile fibres is a vew important part o

l simpIe fibre identification was a relatively easy task; m ost consum ers could tell by appearance and hand

whether a fabric w as cotton, w ool, silk, or Iinen O nce the first m anm ade fibres w ere introduced, theprocess becam e a bit m ore difficult Consum ers usually could identify the fibre com position of fabricsmade of 100 percent rayon or acetate, but blends of some fibres were difficult to identify As more

fibres w ere introduced, the task becam e progressi vel y m ore diffi cul t Today, sophisti cated

techniques are usually required for accurate fibre identification

The purpose of the Textile Fibre Products Identification Act w as to provide inform ation on fibrecontent of textiles at the point of sale Consum ers w ere at once relieved of the responsibility toidentify fibre content of item s they purchased; how everz professionals working w ith textilproducts still m ust be able to identify fibres accurately Such individuals include retailers w hosuspect som e textile products they bought for resale have been Iabeled inaccurately; custom sosicials w ho m ust identify im ported fibres; dry cleaners w ho m ust clean an item from w hich aII

the l abels have been rem oved; extensi on hom e econom i sts w ho are asked to help sol ve a consum er's probl em w i th a textil e product; and forensi c sci entists w ho m ust use a texti l sam pl e to hel p sol ve a cri m e.

For m ost individuals, the only inform ation needed is a qualitative analysis of fibre content: w hat

fibre or fi bres are present in thi s product? For others, a quanti tati ve anal ysi s of the product i s also im portant: in w hat percentages are the fibres present? W i th the num bers of fi bres

available today and the variety of blends being produced, neither analysis is easy

M ethods for qualitative identification of fibres include such procedures as burning tests,

m icroscopy, density determ ination, m oisture regain analysis, dye staining, chem ical solubility,

m elting point determ ination, infrared spectroscopy, and chrom atography Sim plified versions

of the fi rst si x procedures are rel ati vel y easy to pedorm in m ost Iaboratori es They requi re the

use of a drying oven, an analytical balance sensitive to 0.005 gram , a com pound light

m icroscope capable of 200 x m agnification, laboratory glassw are, and a supply of chem icals

A Burning Test:

The burning test is a good prelim inary test for categorizing fibres Observation of burningprovides inform ation on behavior in a flam e, sm oke generation, odor during burning, andash or residue lt never should be used as the only m ethod of identifying a fibre, but itprovides valuable inform ation that m ay be used w ith other evidence to m ake a positive

identification of an unknow n fibre

Blends of fibres are difficult to test using this procedure Tbe reaction of the predom inantfibre m ay m ask the presence of a second fibre, w hich could have entirely different burningcharacteristics Finishes, especially flam eretardant finishes, can also give m isleading

inform ati on Al though the test i s easy to perf orm, i t does i nvol ve the use of an open fl ame, making i t necessary to observe certain safety precauti ons Use a sm all fl am e source i n an area w here

there is no danger of igniting other m aterials A candle in a stable base or a sm all alcohollam p is preferable to a hand-held m atch A nonflam m able pad should be used under theburning m aterial to provide protection from m olten drip and sm oldering ash Do not touchash or tw eezers w hile they are still hot

p- - ure:

The sam ple to be tested should be in fibre form A single yarn from a woven or knitted

fabric should be untw isted to produce a tuft of fibres for testing Use the follow ing

instructions, and observe the reactions of the burning fibre very carefully.

1 Hold the tuft of fibres w ith a pair of tweezers.

2 M ove the tuft close to the side of the flam e; do not place the fibres above or belowthe flam e Observe carefully to see if the fibres m elt,shrink, or draw away from the

or slowl y, or does i t show no sign of igniti on? (b) Does the materi al begi n to mel t? (c)Does the m aterial produce a sputtering flam e, a steady flam e, or no fl ame at all ? (d)

W hen the fibre is rem oved from the flam e, does it continue to burn, or does it self

extinguish?

lf the m aterial is still burning when it is rem oved from the flam e, blow out the flam e.Note the odor and colour of the sm oke, or note that no sm oke was produced whenthe fibre was rem oved from the flam e

Observe the residue rem aining after burning Does a residue drop from thetweezers? Does that residue continue to burn? How m uch residue is Ieft? Does theresidue rem ain red, indicating that it is still vew hot? W hat colour is the ash thatrem ains? Is the ash the shape of the fibre, light and fluffy,or is it bead-shaped?

6 After it cools off, touch the residue or ash Is it soft or brittle? Can it be crushed

easily between the fingers, or is it hard to crush?

Results:

Typi cal fibre reactions for the major natural and manmade fi bre types are given in the

follow ing table W hen interpreting results, rem em ber:

blend m ay com pletely m ask the proper ties of another fibre.

2 Dyes and finishes affect test results Flam e-retardant finishes are especially

Cotton & 1 Does not shri nk away; Burns qui ckl y Conti nues to 1 Si mi l ar to j Li ght, feathery;

f x i ni t es on ont a t 1 bu r n; f er gl ow 1 bur ni ng pape r j I i gh t o c har c oa l

t t Mel ts & fuses away Burns rapi dl y 1 Conti nues to 1 A

crid Irregularly

j f rom f ame; gni t es wi thot ame bur n; hot mol t en shaped, har d

l rea di l y & Sputteri ng; pol ymer drops off bl ack bead

dri ps, mel ts whi I l e burni ng I IMel ts away from Burns sl owl y sel f- extingui shes t Cooking cel ery ' Hard,tough gray

r

fl am e; shri nks

, fuses wi th mel ti ng, : or tan bead

dri ps

0e n Fuses; shri nks & curl s M el ts; burns conti nues to Chemi cal odor Hard,tough tan

wt e Cur l away f om f ame Bur ns sl owl y 1 sel f exti ngui shes i Si I mi l ar o l Smal l br i l

l b u rn ing ha ir b Iack b ead

&lk curl s away from fl ame Burns sl owl y Usual l y Simi l ar to Crushabl e black

& sputters self-extinguishes singed hair beadlunweighted)

Shape of fibr e or

fabric (weighted)

-2 -1 F us es but does ot Bur ns wi t l con t nue s o Che mi c al odor ' So f t k ,

+

s r nk wa y f om mel t g ' l bur n wi t mel t ng gummy mas s

f m e

B Light M icroscopy Test:

A com pound m icroscope capable of at Ieast 200x m agnifications is required for fibre

identification A magnification of 200x may be adequate for tentative identification,

especially of the natural fibres, but is not adequate for viewing the details of fibre structure

The Iens and objectives of the m icroscope, as well as the slides and cover glasses, m ust be

cl ean and free of scratches The li ght source shoul d be adjusted for maxi mum visibil i ty pri or

to Iooking at prepared slides Have materials at hand to sketch the fibres viewed? and haveaccess to a source of photographs of know n fibres to m ake com parisons for identification.The follow ing figure shows the longitudinal and cross-sectional view s of the m ost com m onfibres

Longitudinal m ounts:

It is possible to m ount a single fibre, but it is Iess frustrating for m ost m icroscopists to useseveral fibres A m inim um of ten fibres is useful w hen the m aterial to be studied is a blend.Too m any fibres on a slide m akes it difficult to focus on a single fibre to observe the details

of its sudace contour W hen taking a sam ple from a yarn in a fabric, untw ist the yarncom pletely to separate tbe fibres Tbe basic steps for m aking a Iongitudinal m ount are as

foll ow s.

1 Place a single drop of w ater, glycerine or m ineral oiI on the center of the glass'slide

M ineral oiI provides the best definition, but the other m aterials are adequate

2 Carefully place the fibres in the drop of liquid w ith the Iength of the fibres parallel tothe Iong dim ension of the slide

3 Place the cover glass lightly over the drop of Iiquid and the specim en Tap the cover

gl ass gentl y to rem ove air bubbl es.

4 W ith the objective in its highest position, place the slide on tbe stage of the

m icroscope Low er the objective carefully before trying to focus the slide It is veryeasy to dam age the objective by scratching it or sm earing it w ith oil

Focus on low pow er and observe the fibre before focusing on high pow er N ote thegeneral shape of the fibre, then look at it carefully for signs of scales, convolutions,pockm arks, striations' and other features Look carefully to see if m ore than onetype of fibre is present

6 W ith the m icroscope focused on high pow er, m ove the fine adjustm ent very slow ly

to see if variations in surface contour are visible Again, look carefully to see if m orethan one fibre type is present

7 Sketch the fibres as seen through the m icroscope, then com pare your sketch w ithstandard photographs to conclude w hich fibres m ight be present

<-Regular cotton (X-secti on) Regul ar cotton

(I ongi tudinal view)

M ercerized cotton(X-section)

Regular polyester

( X- secti on)

Del ustered Nyl on 6 (X-secti on)

Regular polyester(l ongi tudinal view)

Trilobal polyester(X-secti on)

Delustered Nylön 6 flongitudi nal view)

-Tril obal nyl on 6,6 (cross secti on)

Pol ypropyl ene (cross secti on)

Orl on Acryli c (cross secti on)

-w q - D + p x #

' y + > < x: , *

Tri o ba I nylon 6,6 (I ongi tud 1 naIview)

Pol ypropylene (longi tudinal view)

Speci al pl asti c and m etal pl ates are avail abl e for m aki ng fibre cross-secti ons Speci al fibre m i crotomes are used for m ore sophi sti cated work W her e such ai ds are not avai l abl e, i t i s possi bl e to m ake a secti on

using a piece of cork, a threaded sew ing m achine needle, and a sharp single-edge razor blade,

The i nstructi ons fol l ow

1 Use a small piece of fine-grain cork no m ore than 1 cm (0.5 inch) thick Cut so that it

i s flat on one si de The cork w edge shoul d be of a diam eter sm al l enough to sl ice easi l y.

Thread the sew ing m achine needle, and carefully force the point of the needle

through the cork until a I oop of thread can be form ed.

Form a thread I oop around your finger and pul l the needle back through the cork.

The needle m ay then be renhoved; it w as needed just to push the thread through the

cork to form the I oop.

4 M ake a sm all bundle of fibre ti fit through the thread Ioop Then, using the free ends

of the thread, carefully pull the looped fibre back through the cork The fibre should

be packed firm ly in the hole of the cork, and fibre ends w iîl be visible on both sides

of the cork After a Iittle practice, estim ation of the exact am ount of fibre to use

becom es easi er

5 Place the flat side of the cork dow n on a cutting board and use the razor blad'e to cut

a thin slice perpendicular to the fibre em bedded in the cork The slice should be no

m ore than 0.5 m m thick M ake the cut w i th a si ngl e, conti nuous m oti on, not a saw i ng m oti on.

6 Pl ace the cork sl ice on a glass sli de Do not use a m ounting m edium or cover glass Focus the m i croscope and observe the cross secti ons of the fibres.

Resul u :

Look carefull y at the shape of the fi brez and com pare i t w i th photom i crographs of know n

fibres M ost natural fibres can be identified by sim ple Iight m icroscopy, but positive

identi fi cati on of m anufactured fi bres i s often di ffi cul t w i th thi s techni que W hen a fibre

blend is present, it is possible to approxim ate the blend Ievel by counting the fibres

M icroscopy is also a good w ay to determ ine the num ber of fibres present in a blend

C Chem irnl R lubiliw Tee q:

Chem ical solubility tests are necessary to identify m ost m anufactured fibres They are

usual l y perform ed after burning tests and m i croscopi c exam i nati on of the fibres Preli m inary burni ng tests usual l y provi de som e i nform ati on about the speci fic fi bres that

m ay be present or the fi bres that are defini tel y not present, and m i croscopy provi des inform ati on on the num ber of fibres to be i denti fi ed and the predom inant fi bres in a blend.

The solubility procedure described in this section is based on the chem icals specified in the

AATCC (American Association of Textile Chem ists and Colourists) qualitative identification

test m ethod ln som e instances, the term soiubility is a m isnom er as the m aterial does notdissolve, but m erely degrades A m aterial that dissolves in a solvent can be recovered fromthat solvent, w hereas a m aterial degraded by a solvent breaks apart but does not dissolve,and so cannot be recovered from the solvent W hen observing solubility tests for fibres, it isnot alw ays possible to determ ine w hether a fibre has actually dissolved or has m erely

disintegrated

AIl chem ical tests should be conducted in a room with proper ventilation and chemical

safety protedion devices The required Material Safety Data Sheet (M SDS) for each

chem ical should be posted in areas where the chem ical is used.Although only very sm all

am ounts of chem icals are needed for testing, accidents som etimes happen.Adhere tochem ical safety rules in perform ing fibre identification tests.W ear protective eye goggles

w hen using chem ical solvents Organic solvents and heated Iiquids should be used only in afum e hood! Follow Iocal laboratory regulations for disposing of used solvents and fibres.pr- -=ure:

The following Chem icals used for solubility test tabte (ists the chem icals and test conditions

used in chem ical solubility testing W hen there is no prior knowlédge of the fibres that m ay

be present, the m aterial should be tested in the solvents in the otder presented in the table.

Once a positive identification is m ade, solvent tesling m ay be term inated.W here prior

inform ation indicates that certain fibres m ay be present, test the unknow n fibre only inthose solvents required for its identification The general procedure for solventidentification follow s

W hen solvents are used at room tem perature, the tests m ay be perform ed in a

watch cw stal, a 50-m I beaker, or a sm all test tube Place a small am ount of the fibre

in the container and add the solvent Use about 1 m l of solvent for 10 mg of fibre.

N -x o j s v-aA jw euuyjW Fx l;

(%1 T (Y *

3 Sodi um hypochl ori te 5 Room 20

4 hydr ochl ori c aci d 20 Room 10

9 Di methyl f orm ami dea 100 90 10

10 Sul furi c aci da 59 5 20 20

13 Hydr of l uori c aci db 50 Room 20

ause i n a fum e hood

buse a nongl ass beaker

2 Tests pedorm ed at the boiling point of the solvent require the use of a ventilated

fum e hood Pour the solvent into a sm all beaker and place the beaker on a hot plate

inside the fum e hood Adjust the tem perature of the hot plate to m aintain a slow

boil Add the fibre to the boiling liquid.W atch the reaction carefully to m ake sure

the solvent does not boil dry Never add additional solvent to the heated beaker!

For tests conducted at interm ediate tem peratures, heat a beaker of w ater on a hot

Iate under the fume hood, an' d adjust the tem perature using a thermometer.Placep

the fibre and solvent in a test tube, then set the test tube in the beaker of heated

w ater.

down and the am ount of the m aterial dissolved Note w hether the material actuailydissolves, degrades into small pieces, or form s a plastic m ass lf all fibres are not

dissolved in a specific solvent, carefully rem ove the undissolved fibres Rinse them inwater, and attem pt to dissolve them in another solvent

Resqlts:

The following Solubility of Fibres table provides fibre solubility test results Com pare theresults to identify a fibre Some of the chem icals in the table are com monly found in thehome Other household products containing sim ilar solvents w ill also dam age or dissolve

fibres Acetone is often a component of nail polish, nail polish rem over, paint thinners, andpaint rem overs Amyl acetate, a sim ifar chem ical, m ay dam age acetate, m odacrylic, and

vinyon fibres Vinegar is a dilute solution of acetic acid; it does not dissolve fibres, but it m aydamage the sam e fibres that are dissolved by glacial acetic acid

Solubil ity of Fibres (Chart for findingthe solvent of a particular fibre)

@t '.' esol is sometim es a com ponent of household disinfectants and antiseptics It is not

C sent in a sufficiently high concentration to dissolve fibres, but it m ay dam age acetate,

YARN AND YARN M ANUFAW URING

An assem blage of fibres that is tw isted or Iaid together so as to fo

rm a continuous strandth

at can be m ade into a textile fabric So a yarn is a strand of natural or m an-m ade fibres orfilam ents that have been tw isted or grouped together for us

e in weaving, knitting,or otherm

ethods of constructing textile fabrics.The type of yarn to be m anufactured will depend onthe fibres selected; the texture, or hand, of the fabric to be m ade; and qualities such aswarm th, resiliency, softness, and durabiiity required in the fabric's end uses

.

Types of Fibres:

A$l the textile fibres are classified according to their staple I

ength into two categories, sucha

s staple fibre and filament

staple sbres:

lt has a lim ited Iength that varies according to the type

, such as cotton, wool, jute etc There are tw

o types of staple fibre, one is short staple fibre another one is Iong st

apie

fib

re Cotton is m ainly short staple fibre and other m axim um natural fib

res are long

staple except silk Silk is only natural fibre that is filament

.

Filam ent:

lt has continuous Iength that m eans the Iength of filam ent is e

qual to the Iength of yarn

.AIl man-m ade fibres are filam ent M an-m ade fibres are produced as filam ent

, althoughth

ey used as staple fibres if necessary.So filam ents are used as staple fibre but staplefibres never used as filam ent.

Classification of Yarn:

U aee** H of yarn O ing to their struG ure:

Yarns m ay be divided into three types according to their structu

re as follows:

1 R apl e 5h> yar ns or * un yarns ( si ngl e yarn):

Spun yarns are m ade by m echanical assem bly and twisting togeth

er (spinni ng) of stapl e fib

res Ring spinning,Rotor spinning

, W rap spinning,Ai r-jet spi nning etc machi nes are

used to produce this spun or single yarns.

%( Z '

Single or Spun yarn

? ? ( - % ( y ; ' ( ' ' ' ' - ' - w ( : = L ts r s ( L t a t -Ring Spun Yarn Rotor Spun Yarn

%

d ' .(

Carded cotton (ri ng) yarn

' )' : o; ' q ) ' ' - , ' :y ( ) g

r l % ' t ' - .'c- 1 ; Fr ; .- ( @ ) ik 13

Combed cotton (ring) yarn

2 Ply yarn:

Si ngl e yarns are used i n the majori ty of fabrics for normal textil e and clothing

applications, but in order to obtain special yarn features, particularly high strength andmodulus for technical and industri al appli cati ons, pl y yarns are often needed A lolded

or pIy yarn is produced by twisting two or m ore single yarns toqether in one operation,

and a cabled yarn i s formed by twisting together t-o or m ore fol ded yarns or a combination of jol ded and singl e yarns The twi sting together of several si ngl e yarns

increases the tenacity of the yarn by im proving the binding-in of the fibres on the outer

Iayers of the com ponent single yarns PIy yarns are also m ore regular, sm oother and

more hard wearing The di recti on of twi sting is desi gnated as S or Z, just as in singl e

yarns Norm ally the folding twist is in the opposite direction to that of the single yarns

Folded or Fly yarn

Four-Folded or Fly yarn

Core Spun yarn

3 Filament yarns:

A fil ament yarn i s made from one or more conti nuous sirands call ed fil am ents where

each com ponent filam ent runs the whole Iength of the yarn Those yarns com posed ofone filam ent are called m onofilam ent yarns, and those containing more fiiam ents areknown as mul ti filament yarns For apparel appl icati ons, a mul tl hl ament yarn may contai n as jew as two or three jilaments or as mlny as 50 hlaments I n carpeti ng, forexam ple, a filament yarn could consist of hundreds of filam ents, M ost m anufactured

fi bres have been produced i n the form of a fil ament yarn Silk is the onl y major natural

filam ent yarn

Mono-filament yarn

* ( $- : ' ' ' ' ' : '

Twisted multi-filament yarn

Stuffer-box Textured yarn

According to the shape of the fiiam ents in the yarn, filam ent yarns are classified intotwo types, flat and bulk The filam ents in a flat yarn Iie straight and neat, and areparallel to the yarn axis Thus, flat filam ent yarns are usually closely packed and have a

sm ooth surface The bulked yarns, in which the filamentk are either crim ped or

entangled w ith each other, have a greater volum e than the flat yarns of the sam e Iinear

density,

Texturinq is the main method used to produce the bulkedfi lament yarns A textured yarn

is made by introducing durable crim ps, coils, and loops along the Iength of thefilaments As tertured yarns have an increased volum e, the air and vapour perm eability

of fabrics made from them is greater than that from flat yarns However, forapplications where Iow air permeability is required, such as the fabrics for air bags, flatyarns may be a better choice Textured yarns are used for Stockings and tights,

sw imw ear, sportsw ear, outerw ear, underwear, carpets, sew ing and overedge stitchingthreads for extensible fabrics

Elaq- œ ofn rns arr- ingto thei r use:

Yarns m ay be divided into two classifications according to their use:

W eaving yarns and knitting yarns

W eaing Yam s:

Yarns for woven c10th are prepared for the intended end use Yarns to be used in thewarp, the lengthw ise direction of a c10th, are generally stronger, have a tighter twist,and are sm oother and more even than are yarns used for filling, the crosswise direction

of a c10th Novelty yarns m ay be used in the warp, but they are generally found in the

filling Highly twisted crepe yarns are usually found used as filling yarns

These may be divided into yarns for hand knitting and yarns for m achine knitting.Knitting yarns are more slackly twisted than yarns for weaving Hand knitting yarns aregenerally ply, whereas those for m achine knitting can be either single or ply Thefollowing are some of the yarns used for hand knitting:

1 Knitted worsted: The four-ply all-around yarn used for accessories, for the house,and for apparel This is the most com mon weight of hand-knitting yarn,com prising 90 percent of the handm ade yarn business

Fingeri ng (baby or sock) yarn: The fine yarn that was ori gi nall y wool , but i s found

m ost com monly in acrylic for comfort and ease of care

Sport yarn: The three-ply yarn used for socks, sweaters, and hats

Shetland yarn: The two-ply yarn used for sweaters

Fashion or novelty yarn: Any novelty strud ure

All the yarns li sted may be found in any fibre Of the major fi bres, rayon i s the least Ii kel y to be

used in the handmade yarn business

Types of totton yarn:

There are two types of cotton yarn according to their manufacturing process as followsz

i Carded yarn

II Combed yarn

Flow thart of carded yarn m anufad uring w ith input or feed and output or del ivew produd :

lnptlt or Feed produd M anufacturing process Output or Delivery produd

Rovi ng Ring- Spi nni ng Yarn (spi nni ng bobbin)

(Spi nni ng Frame)

i

(Auto coner)

Blow room Section:

Basit opera:on inl e Blow -room :

* Opening the cotton bale

Cleaning the cotton fibre

Dust removal

* M ixing and blending of fibres

Even or uniform feed of m aterial to the next process i.e card

Objeds of Bl ow-x m:

The basic purpose of blow-room Iine is to supply following qualities of fibre tufts to the carding

pr0CeSS

* Small fibre tufts

Homogeneously mixed or blended tufts

Clean fibre tufts

Convert fibre tufts into a fibrous sheet, is called Iap

Blending: The method of mixing different fibres within a specific ratic is known as blending.

M ixing: The method of com bining identical fibres in various grade of different ratio is known as

m ixing

Conventional Blowroom Iine:

There are different types of conventional blow-room Iine, It differs manufacturer tomanufacturer For exam ple a typical blow-room Iine as follows:

1 Hopper bale opener

2 Ultra cleaner or Step cleaner

3 Vertical or twine opener or cleaner

1 > Ie 1ay n, * ie 2 B.l* ne 3 4 çher or PIe- ker

Typical conventional Blow-room line

deli very produd :

Input or Feed product M anufacturing process Output or Delivery product

Process and Produd of the cotton Ring spinning:

Com bed sliver

Yarn cops)

I , #

Breaker Drawing Pre-com b Draw ing

Ring fram e Post-comb Drawing or Finisher Drawing

sim plex or Roving frame or Speed frame

A modern blow -room Iine as follow s:The follow ing blow-room Iine provide by the Trùtzschler

Bale plucker or bale opener

1

Trùtzschler chute feed

*

' 7 '

x ' z

*

2

l I

* y

'

Nw x 1/

Triitzschler RN cleaner

M odern Blow-room section

Cardi ng i s a process i n whi ch fi bres are opened (almost to si ngl e fibre staple), parallelised andremoves dust, im purities, neps, short fibres to produce a continuous strand of fibres calledsliver of uniform weight per unit length.

Objeds of Cardi ng:

Carding is one of the m ost im portant operations in the spinning process as it directly

determ ines the final features of the yarn

, above aII as far as the content of neps and husks are

concerned There are many objecti ves of the cardi ng process and these can be summari zed as:

* Individualization of the cotton fibre at a single fibre staple state i.e. opening the tufts intoindividual fibres;

* Elim ination of the rem aining im purities i.e. elim inating alI the im purities contained in the fibrethat were not elim inated in the previous cleaning operations;

@ Disentangling of neps i,e rem oval of neps;

* Selecting the fibres on the basis of length,rem oving the shortest ones;

* Fibre blending and orientation;

@ Farallelising and stretching of the fibre;

* Finally produce a continuous strand of fibres called sliver of uniform weight per unit length i

e.transform ation of the lap into a sliver, therefore into a regular m ass of untwisted fibre.

,a machine that in practice is a system of

rotating organs, mobile and fixed flats,covered with steel spikes that go by the name of wiring

.

Doubling and Draw ing:

ln preparing the fibre tufts for spinning, doubling and drawing represent two essentialoperations and their com bined effect perm its a sliver w ith a more regular section to beobtai nedt through doubl i ng) equi pped wi th paral lel fi bres (through drawî ng) as wel l as thecount requested by the spinning plan

The draw ing operation done with the m achine called the drawframe, permits a hom ogeneousblend both with fibres of the same nature as well as fibres with a different nature; the doublingsteps are usually between four and eight

On a par with fibre characteristics such as Iength and fineness, a sliver with parallel fibrespermits a yarn with better regularity and resistance The drawing depends on some factors such

as the num ber of doublings carried out and the value of the count of the entry Sliver anddelivery sliver W ith drawing, curls, crim ps and hooks are also elim inated, m eaning the fibresfolded in on themselves, present in the carded sliver

Drawing is a process in which the sliver is elongated by passing it through a series of pair ofroflers, each pair moving faster than the previous This permits com bination of several sliversand drawing and efongating them to straighten and create greater uniform ity to form a regularsliver of smaller diam eter This action pulls the staple Iengthwise over each other, therebyproducing longer and thinner slivers, Finally the sliver is taken to the sliver can

3-cylinder draftingunit on top of 4, with pressure bar

The main objeds of the Draw-Frame are below:

@ Crimped, curled and hooked fibres are straightened;

* Parallelisation of fibres;

* Reduction of sliver weight per unit length;

* Reduce irregularities of fibres by doubiing and drafting;

@ Remove remaining dust from sliver;

* Blending of fibre to provide compensation of raw m aterial variation

There are two passages of drawing are uses

* Breaker drawing and

Finisher drawing

The main difference bet

ween them, like on the card, there are also autolevelers on the finisher'

drawframes, whose job i t i s to correct the draft i n functi on of variati ons i

n the fi brous mass, to

intain the section of sliver as even as possible and therefore reduce the frequency of

z'. 1 Autoseveller module

; 2 On-board com puter

( s M ain m otor

-r The Iap form er has

, furtherm ore, the task of form ing the interfacing or Iap

, w hich is efnployed

'

to feed the combing m achine.The I ap i s obtained by doubl ing a certai n number of sl i vers (from t

.

y 16 to 32) previousl y subject to a drawing passage.The slivers are fed side by side, passing

, through rollers and stop motion. The slivers enter the drafting section and then calendar