Yarn

(Yarn is a long continuous length of interlocked fibres suitable for use in the production of textiles, sewing, knitting, weaving, embroidery and rope making. rarn can be made from any number of natural or synthetic fibers. n other word, Yarn can be defined as a product of substantial length and relatively small cross section consisting of fibers or filament with or without twist. Assembly of fiber or filaments with or without twist.

★Yarn Twist 

Twist is the measure of the spiral turns given to Yam in order to hold the fibres or threads together Twist is necessary to give a yarn coherence and strength. Twist is primarily instructed in to a staple yarn in order to hold the constituent fibres together, thus giving strength to the yarn. 

★Yarn Twist Measuring Unit 

TPI Twist Per Inch 

TPM (Twist Per Meter

 TPCm Twist Per Centimeter)

★Twist Direction 

Z Twist: If spiral turns are given into the yarn in clockwise direction then it is called Z twist. 

S Twist: lf spiral turns are given into the yarn in anticlockwise direction then it is called S twist of yarn.

★TPI Depends on- 

Primarily twist is proportional to yarn strength that means yarn strength is increases with the increasing of yarn twist. But after a certain limit, with the increasing of yarn twist strength is decreases and then occurs yarn rupture. So number of twist depends on-

 Yarn strength

 Cost of yarn

 Length of fibre 

End use of yarn

 Machine used for twisting

★Yarn Evenness or Regularity

 Yarn evenness is a measure of the level of yarn diameter along its length. In other word, it means variation of yarn Count. 

Normally it is measured by mass per unit length of yarn. If mass per unit length is equal along the yarn then the yarn is regular. 

Yarn imperfection causes inregularity. Yarn imperfection means thick place, thin place and neps present in the yarn. 

Yarn imperfection is unwanted in many cases. But slightly imperfection is wanted only for producing of slub yarn.

★Yarn Count or Linear Density

 Yarn Count is the relation between mass and length of yarn. 

Count is a numerical value which indicates the coarseness or fineness of yarn.

 According to Textile Institute, Count is a mathematical expression indicates the mass per unit length or length per unit mass of yarn.

★Types of Yarn Count

 Direct Count: In this system count indicates the mass per unit length of yarn. Such as, Tex Count (NT), Denier Count (No) etc. 

Tex Count Mass of 1000m of yarn measured in gm is called the Tex count oi yarn. li 1000m yarn mass is 20 gm then yarn count is 20 Tex

 Denier Count: Mass of 9000m of yarn measured in grm is called the Denier Count of yarn. If 9000 m yarn mass is l 20gm then yarn count is 120 denier.

 In Direct System, Yorn will be coarser when count is increases.

★Properties of a Good Yarn

 Reasonable strength

 Reasonable uniformity 

High amount of fibre (80 fibers, minimum 30) 

Less amount of short fibre 

Correct amount of twist (20 25 TPT, 30 count) 

Correct count 

Good handle 

Good drape quality

 Specific elasticity 

Good dye absorbency.

★Assessment of Yarn

 Fibre contents of yarn 

Fibre quality

 Strength Number of fibre in its cross section

 Number of short fibre

 Elastic properties

 Number of twist 

Evenness of yarn

 End use of yarn.

★Mixing & Blending

 Mixing or blending is combining of different kinds and different qualities of fibres together in haphazard proportion or based on measurement to improve their physical properties. For example, mixing of lower quality cotton to higher quality cotton, mixing of cotton and polyester etc. 

Objectives of Mixing & Blending

 To improve the physical properties such as strength, comfortness, softness, water absorbency etc To reduce the cost. To improve the quality.

★Why Cotton & Polyester are Mixed Together 

To increase the average strength.

 To increase the comfort ability.

 To increase the crease resistance power. 

To increase the durability. 

To reduce the cost. 

To get average luster.

★CVC Yarn 

CVC means Chief Value of Cotton. Cotton and polyester fibres are blend together but cotton percentage is more. Such as, 65/35 CVC means 65% cotton and 35% polyester This type of yarn has higher comfortability with less strength. 

PC Yarn 

PC means Polyester Cotton. Cotton and polyester fibres are blend together and but polyester percentage is more than cotton. This type of yarn is characterized by higher strength with less comfort.

★Classification ofYarn

 On the Basis of Fibre Length 

Staple Yarn- composed of short-staple fibers that are twisted or otherwise bonded together Staple yarns are fuzzy yarn with protruding ends

 Filament Yarn- Filament yarns are composed of long fibre grouped together with or without twist. There are two types-

★Mono Filament Yarn: 

This types of yarns are made from a filament. It has no twist. It is comparatively coarse and stiff. Cutting ends are sharp.

 Multi Filament Yarn:

 These types of yarns are made from more than one filament twisted together. Flexible yarns are manufactured by applying twist on filament yarn and then twist setting. These type of threads are made from polyester and it is very strong. It has low cost.

★On the Basis of Fibre Content

 Natural Yarn: The yarn which is made from natural fibre is called natural yarn. Such as, cotton yarn, linen yarn etc. 

Synthetic Yann: The yarn which is made from synthetic fibre is called synthetic yarn. Such as polyester yarn, nylon yarn. 

Blend Yarn: Blend yarn is made from both natural and synthetic fibre blend together. Such as, polyetser cotton blended.

 Green Yarn: Eco-friendly yarns are called green yarn This type of yarns are made from natural fibre without using any chemical such as organic cotton.

★On the Basis of Amount of Twist 

Low Twist: Used to only hold the yarn or fibre together in case of multifilament yarn. Only l-2 turns per inch. 

Average twist: Most common for staple fiber yarns; most durable spun yarns.

 Hard twist: Harsher hand & more turns per inch

 Crepe yarns: Highest TPI (40-80); twist & kink when removed from fabric.

★On the Basis of Structure 

Single Yarn: Spun yarn made by mechanically assembly or twisted together such as, Carded yarn Rotor yarn etc. 

Plied Yarn: A piled yarn IS sometimes called folded yarn also Two or more single yarns are twisted together and plied yarns are made. 

Cord Yarn: Cord yarns is also called cable yarn. Two or more plied yarns are twisted together and cord yarns are made.

★On the Basis ofTheir End Use

 Weaving Yarn: Yarns that are used in production of woven fabric. Normally stronger, higher twist, good regularity and less hairiness.

 Knitted Yarn: Yarns that are used in the production of knit fabric. Normally stronger, lower twist but lower quality than weaving yarn.

★On the Basis of Regularity

 simple Yarn This are spun or filament yarn alike in all the area of the yarn. The yarns are almost sa in appearance in the area. 

Fancy Yarn: Yarns that are deliberately have unlike parts and are irregular at intervals. Irregularity may be found in random or regular interval. Named for the effect that dominates fabric. There are many kind of fancy yarn.

★Slub Yarn: 

The yarn which contains thick and thin places in regular or random interval. 

Corkscrew Yarn: It contains two yarn on which one yarn is straight and another one is twisted on the straight yarn. 

Crepe Yarn:

 Crepe yarns are made by tightening the twist given to the yarn resulting in a kinked or looped yarn.

 Melange Yarn: Different colors of fibres are blend together and produces melange yarn. The yarns have different color on the surface depends on number of colored fibres.

★Special Type of Yarn 

Core spun Yarn: Core spun yarns are two component structure with Core and Sheath. Generally continuous filament yarn is used as core and the staple fibres used as sheath covering. The core-spun yarn used to enhance functional properties of the fabrics such as strength, durability and stretch comfort. 

Textured Yarn: A term used to describe filament yarn that has been treated to change its hand, increase bulk or increase stretch. Normally it is done by texturing more continuous filaments together.

★Sewing Thread

 The yarn is plied to make sewing thread and may be treated with solid or solid waxy materials to secure a smooth, compact strand that is quite flexible but that presents no loose fibres.

★Difference Between Yarn & Sewing Thread 

Yarn is single where as sewing thread are always plied. Sewing thread may contain two or more ply of yarn Sewing thread are treated with waxy like finishing materials but yarn does not contains finishing materials. yarn may be contains loose fibre on its surface where as sewing threads surface is smooth and flexible. Most of the case sewing thread strength is higher than yarn strength.

★Yarn Defects 

Count variation 

Yarn irregularity Frequent occurring faults (Thick place,Thin Place and neps)

 Seldom occurring faults Long thick place, Long thin place)

 Yarn hairiness

 Bad piecing 

Lot mixing.