6. yarn classification & terminology

Fabric Science I Subject Code B FP (T) 1 09 T National Institute of Fashion Technology, India

Fabric Science ISubject Code B FP (T) 1 09 T National Institute of Fashion Technology, India

Unit-6Types of Yarn and ClassificationContent 6.1 Classification 6.2 Structure 6.3 Twist 6.4 Properties 6.5 Uses 6.6 Fancy yarn 6.7 Yarn Numbering System6.8 Sewing Threads

Fabric Science-1 Unit-6YarnYarn is a grouping of fibers arranged in parallel and twisted together (staple fiber or Filaments) to form a continuous strand with twist or without twist.Yarn is a long continuous length of interlocked fibers, suitable for use in the production of textiles, sewing, crocheting, knitting, weaving, embroidery and rope-making

Fabric Science-1 Unit-66.1-Textile Yarn Classification

Fabric Science-1 Unit-66.2 StructureSingle yarn:It s made from the group of filaments or Staple fiber

Double yarn:Its made by twisting together two single yarn

Cabled Yarn:Its made by twisting together two or more doubled yarn

Fabric Science-1 Unit-6

Fabric Science-1 Unit-6Yarns Spun and Filament The process of twisting fibers into yarn is called spinning.

There are two types of yarns spun and filament.

Spun yarns are composed of relatively short lengths of fibre twisted together.

The short lengths of fibre are called staple fibres

It is important that staple fibres possess sufficient surface friction to adhere to each other

Fabric Science-1 Unit-6Yarns Spun and Filament Filament yarns are made from long, continuous strands of fiber.

Monofilaments made from a single filament, have limited use in some decorative fabrics.

Multifilament yarns made by twisting many filaments together loosely or tightly.

Fabric Science-1 Unit-6Fabric Science-1 Unit-6

Spun Yarn

Spun yarn is manufactured from short fibres, which are called as staple fibres. So spun yarn can be otherwise called as staple yarn. The yarn can be made from either natural or man-made fibres. In case of natural fibres most of them will be short length. Fabric Science-1 Unit-6Fabric Science-1 Unit-6 A staple-spun yarn is a linear assembly of fibers, held together, usually by the insertion of twist, to form a continuous strand, small in cross section but of any specified length.

Synthetic Spun YarnIn case of man-made fibres all the types of fibres are in the form of continuous filament. To make spun yarn all these filaments should be cut into small staple fibres at required length.

Fabric Science-1 Unit-6Mono, Multi and Microfilament YarnsFilament yarns may be composed of one single filament yarn or of many filaments and are known as monofilaments or multi-filaments respectivelyAn important physical difference is that a mono-filament yarn of a given diameter is stiffer and less flexible than a multi-filament of same diameterAnd given two multifilament yarns of equal diameter(denier), the yarn composed of fewer, but coarser, filaments is stiffer and less flexible than the yarn consisting of a higher number of finer filament yarnsTechnological developments in manufactured fibre processes have made possible the generation of fibres such as nylon, polyester, lyocell and others to be produced in diameters finer than silk(microfilament)These fine fibres are called microfibres and also known as microdenier



Comparison of Spun and FilamentThe three main properties used to compare are uniformity, yarn smoothness& luster and yarn strengthFilament yarns are more uniform in diameter than spunIn filament yarns, the same number of filaments are present at every point along the yarn A multi filament yarn composed of 40 filaments has forty filaments along its entire lengthThis is not the case with spun yarns, where, for example, at one point there may be 40 fibres, at another, 43 and at still another 37Filament yarns are generally smoother and more lustrous than spun yarns

Fabric Science-1 Unit-6The smooth surface of the filament yarns can sometimes be disadvantageous, causing yarns to slip and slip easily within a fabric

When a spun yarn is broken, some fibres break and others just slide away from each other

When a filament yarn is broken, every filament in the yarn breaks

More twist in the spun yarn increases its strength by increasing the pressure exerted on the fibres

Fabric Science-1 Unit-6Textured Multi Filament Yarn To give the filament yarns the properties like bulkiness, strtchig & soft hand which they are lacking, the yarn are texturised. Texturising is given waviness artificially to the straight ;filaments of synthetic yarns. Two major types of texturised yarns are stretch yarn and bulk yarn. There are several methods followed to manufacture these yarns.

a) Gear crimp methodb) Stuffer Box method c) Knit-De-knit methodd) Edge crimping methode) False twist method etc.

Fabric Science-1 Unit-6Gear crimp methodIn this method of crimping (giving waviness) of yarn is done by heated gear wheels. As the yarn is passed between the wheels it is crimped into a jagged fashion in conformation to the gear teeth and is heat se. Since the fibre is a thermoplastic (becomes semi-liquid state when heated ) one of this crimp becomes permanent one in the yarn after cooling. In other methods the crimp is given to the yarn in some other way.

Fabric Science-1 Unit-6Core Spun YarnsCore Spun yarn structure is the combination of filament yarn and spun yarn together. The main advantage of filament yarn is its high strength and the main advantage of the spun yarn is its bulkiness, soft handle and more moisture absorption. In the core spun yarn both the yarns advantages are combined.In the core spun yarn filament yarn is kept in the middle and the staple yarn is formed around it. This core spun yarns are generally used as sewing thread in heavy sewing applications.

Fabric Science-1 Unit-6Poly-Cotton Core Spun Yarn :In this yarn multifilament core is of polyester and the sheath (the part around the core) is formed by cotton staple fibres. It helps to enjoy the benefits of cotton as well as the high strength of filament yarn which cotton is lacking.

Poly-poly Core Spun Yarn :

In this yarn multifilament cores is of polyester filament fibres and the sheath is formed by the staple (short length cut) polyester fibres. It helps to get the good strength from both core and sheath polyester fibres. Also it gives good resistance to abrasion.Fabric Science-1 Unit-66.3 Yarn TwistIn a yarn the fibres are hold together by twisting each other.

In spun yarn if the twist is not sufficient, the fibres cannot hold each other firmly so the result will be the poor strength of yarn. Twist is essential either in spun yarn and filament yarn.

There are two factors in twist to be considered.Amount of twist &Direction of twist.The amount of twist is an important factor in finished consumers goods. It determines the appearance as well as the durability and serviceability of a fabric. The amount of twist also depends upon the type of fabric to be woven.

Fabric Science-1 Unit-6Yarn TwistTwist : Number of turns given to the yarns when it is hold in the vertical direction Twist direction S or Z TPI Turns per Inch.

Fabric Science-1 Unit-6Structure Z- and S-twist yarn


Yarn twistFabric Science-1 Unit-6Yarns are made by twisting together parallel or nearly parallel fibres

The amount of twist in a yarn is designated as TPI (turns per inch)

Spun yarns with relatively low twist (2 to 12 TPI) are called soft-twist yarns and higher twist (from 20 to 30 TPI) are called hard-twist

Filament yarns usually have very low twist (1/2 to 1 TPI)

Increasing twist decreases apparent yarn sizeFabric Science-1 Unit-6Strength increases in staple yarns as twist increases upto a certain point

Beyond this point , the strength of the yarn begins to decrease

Twist in filament yarns does not increase strength but merely serves to keep the filaments in the yarn together

Some filament yarns are purposely made with high twist to produce a pebbly, harsh surface effect

These yarns are called crepe-filament yarns and the twist is referred to as crepe-twist

Twist DirectionTwo types of yarn twist: S and ZIn S-twist yarn, the spirals run upward to the left, corresponding to the direction of the diagonal part of the letter SIn Z-twist yarn, the spirals run upward to the right, similar to the diagonal part of the letter ZYarn twist direction is not an element of quality because it does not affect properties such as strength and abrasion resistanceThey are important to the fabric designer and stylist because the direction of twist affects the surface appearance of fabricsCrepe fabrics are sometimes made by combining S and Z twist yarns to produce the balanced, pebbly effect on the fabric surfaceFabric Science-1 Unit-66.4 Properties

*Yarns intended for soft-surfaced fabrics are given low twists,*Yarns intended for smooth surfaced fabrics are given more twists.*It contribute strength, smoothness, elasticity and wrinkle resistant (the ability to become flat after given some crease) to fabrics.*Yarns intended for crepe fabrics are given maximum twist.

Fabric Science-1 Unit-6Yarns classified by number of Parts Single, Ply and Cord(Cabled) yarnsYarns are also categorized as Single or Ply or Cord(Cabled)When a ply yarn is untwisted, it separates into two or more finer yarns and when a single spun yarn is untwisted, it comes apartPly yarn therefore may be defined as two or more single yarns twisted together to form one new yarnPlying of filament yarns can be done to produce unique effects on novelty yarns and metallic yarnsPly yarns require better-quality fibre, more labour and special machinery and hence they are costlyCord yarns are made by twisting together 2 or more ply yarnsUsed in making ropes, sewing thread etc

Fabric Science-1 Unit-6Doubled YarnsConsists of 2 or more single strands treated as one in the weaving process but the strands are not twisted together

Ply and double are different as in case of ply they are twisted and are more stronger than double yarns

Used for ornamental effect as it produces lustre and softnessFabric Science-1 Unit-6Carded and Combed YarnsIt refers the method used to make cotton and cotton blend spun yarns

All staple fibres have to be carded to help clean and disentangle the fibres

For less costly fabrics, the fibre is carded and formed into a thick rope of loose fibres called sliver

The sliver is then made into yarn by drawing and spinning

For finer fabrics, the carded cotton in the form of sliver goes to the combing unit, which further cleans the fibres and puts them in parallel positionCombing also removes short fibres Fabric Science-1 Unit-6Fabric Science-1 Unit-6Combed yarns have fibres in more parallel position and are in uniform length, fewer impurities/dirts, uniform diameter, feel smoother, softer and more expensive than carded yarns

Combed yarns are used in fine shirting and luxury sheeting

Denim and terry cloth are two fabrics typically made exclusively of carded yarns

This gives denim the natural, rugged look

The fuzzy, soft bulkiness of carding helps terry cloth remove moisture easily

6.5 Uses


6.6 Fancy yarns or Novelty yarns



Novelty YarnsFabric Science-1 Unit-6Slub Yarn

Fabric Science-1 Unit-6Snarl Yarn


Snarl YarnFabric Science-1 Unit-6

Fabric Science-1 Unit-6Spiral & Corkscrew


Corkscrew YarnFabric Science-1 Unit-6Chenille yarn

Fabric Science-1 Unit-6Knot / Nub / Spot yarn

Fabric Science-1 Unit-6Knot / Nub / Spot yarn

Fabric Science-1 Unit-6Loop Yarns


Boucle or Loop yarnFabric Science-1 Unit-6Fancy yarns

Fabric Science-1 Unit-6Fancy Fabric

Fabric Science-1 Unit-6Fancy Garment


6.7 Yarn Numbering System

Yarn number is a numerical representation of linear of density of yarn. In yarn there is a fixed relationship between the weight and length of the yarn. This relation indicates the thickness of the yarn. The number is also called as yarn count. The count may be expressed according to the traditional method or based on metric system of measurements.





Direct SystemIn the Direct System, Yarn number is calculated based on weight per unit length. Here the length is kept constant and weight is measure to calculate yarn number. In this system yarn number and yarn thickness are directly proportional to each other, when the yarn thickness increases yarn number also will increase.Tex System :Tex system is called as universal system of yarn numbering. This is followed all over the world. Tex is calculated based on number of grams in one kilometer length of yarn and that is the Tex number.Fabric Science-1 Unit-6Fabric Science-1 Unit-6


TEXDenier Fabric Science-1 Unit-6


Indirect systemIn this system yarn number is calculated based on length per unit weight. Weight is kept constant and the length is measured to calculate the yarn number. Here the yarn number and thickness are inversely proportional , when the yarn thickness reduces yarn number will increase.

Count = No. of 840 yards / 1 lb

Fabric Science-1 Unit-6Fabric Science-1 Unit-6Indirect (count system)


Fabric Science-1 Unit-6English Count System


Fabric Science-1 Unit-6Worsted System

Fabric Science-1 Unit-6Metric Count system



Yarn numbersystemSymbolicAbbreviationUnit ofLengthUnit of MassUnit of Yarn countCotton (English)NeC840 Yds1lb840 Yds/lbLinenNeL300 Yds1 lb300 Yds/lbWoolenNaC300 Yds 1 lb300 Yds/lbWordstedNcW560 Yds1 lb560 Yds/lbMetricNm1 Km1 KgKm/KgOther SystemsFabric Science-1 Unit-6Fabric Science-1 Unit-6Count Conversion


6.8 SEWING THREADSewing threads are the linear mediums used to form stitches in fabrics. They are made from the same raw material used to make yarns. Sewing thread usually is less than 1/1000 th of the weight of an apparel item, and yet it may carry more than one half the responsibility for its performance. There are different types and varieties of sewing threads available.Fabric Science-1 Unit-6

Fabric Science-1 Unit-6Required Characteristics of sewing threadsMust have,High stability to bendingGood strengthLimited elongationMinimal shrinkage and Good abrasion resistanceFabric Science-1 Unit-6Thread Numbering SystemSewing thread numbering system is slightly different from the regular yarn numbering systems.

The commonest system and the one used for synthetic and core spun threads is the metric ticket number system.

It is derived from the number metric (Nm) yarn count system which refers to the number of 1000m hanks which weigh 1 Kg.

The metric ticket number system for sewing thread is based on a three fold equivalent of the number metric system and relates its number to the finished thread rather than to the single yarns from which it is made.Fabric Science-1 Unit-6The ticket number is calculated via the resultant count, recalculated into three fold terms whatever the number of plies of yarn twisted together to form the thread.

The metric ticket number is arrived by multiplying the resultant thread count by three.

Resultant count is arrived by dividing the single yarn count in the thread by total number of plies.

For example, a sewing thread is made from Nm 120 number two yarns. The resultant count of this thread is 120/2=60 and the ticket number of this thred is 60 X 3 = 180.

Other examples are; a thread of Nm 80/2 is Tkt 120. Nm 30/3 is Tkt. 30, Nm 20/1 is Tkt 60, Nm 60/3 is Tkt 60, Nm 40/2 is Tkt 60 etc.

Fabric Science-1 Unit-6Cotton sewing threads are sized on the cotton ticket number system which works on the same principle but the figures do not denote the same size in terms of diameter.

For example a cotton sewing thread is made from three 60 Ne single yarns.

The resultant count of this thread is 60/3=2 Ne and the Tkt. Number of this thread is 20 X 3 =60.

Fabric Science-1 Unit-6The sewing thread sizes available in the commonest types of thread i.e. spun polyester or polyester / cotton core spun thread and their likely end uses are given below.

Fabric Science-1 Unit-6Thank youFabric Science-1 Unit-6

6. yarn classification & terminology

Documents

staple yarn

staplespun yarn

doubled yarn fabric

single yarn cabled yarn

single filament yarn

fancy yarn

structuresingle yarn

monofilament yarn