Yarn

The twisted from of fiber is called yarn.

Another types of yarn

Flow chart of Rotor yarn:Input Machine Out putRaw material Blow- room LapLap carding m/c Carded sliverCarded sliver Draw frame Drawn sliverDrawn sliver Rotor spinning Rotor yarn

Types of spinningHand SpinningRing Spinning 1) Carded 2) CombedRotor spinningAir jet SpinningCompect spinning

Image of spinning

Hand Spinning Rotor Spinning

Air jet spinning

The following properties of cotton fibers are considered for spinning.

oSpinning limitoYarn strengthoYarn evennessoYarn fullnessoDrop of the fiber productoLusteroHandleoProductivityoFibre fineness

Their description:Fineness: It is measured in Micron air value. The higher micron value the fibre regarded as coarser.Rating of MIC valueMIC DescriptionLess than 3.0 Very fine3-3.6 fine3.7-4.7 medium

MIC Description4.8-5.4 Coarse5.5-Above Very coarse

MaturityMoisture Ratio= +0.7

If M.R= 0.85, good fibreM.R =0.75,average vfibreM.R =0.65, poor fibre

Fiber length:Staple length Yarn Quality Fibre length influence Spinning length Yarn strengthYarn evennessYarn hairinessHandle of the productLuster of productProductivity

Length uniformity:Length uniformity influences on-Yarn regularityEnds downHigh wastage in combing.High liberation and machine contamination in spinning,weaving and knitting.

Strength: Toughness of fiber has a direct effect on yarn and fabric strength.Fiber strength Yarn and fabric strength Minimum Strength of textile fiber is approximately 6 CN/Tex (about 6 k.m breaking length)Some significant breaking strength of fibers are:Polyester: 35-60 CN/TexCotton:15-40 CN/TexWool: 12-18 CN/Tex

Fiber cleanness:In additional to usable fiber, cotton contain foreign matter of various kinds-•Vegetable matter•Mineral matter•Other matter Accept the range of foreign materials to the bale:Up to 1.2% Very clean1.2-2% clean2.0-4% medium

4-7% Dirty7 and above Very dirtyAccording to intemational committee for cotton testing methods the following types are to be distinguished:

Trash Above - 500 mmDust 50-500 Micro dust 15-50Breathable below 15

Bale management: Testing, sorting and mixing bales according to properties of fiber for producing specific good quality yarn at minimum cost is called Bale management.Object of Bale management:An evening out of the quality characteristics .A means of avoiding quality jumps.A possibility of reducing costs. As a result of improved of the fiber characteristics

Importance of bale management:If bale management is absent-Lot to lot variation is called fabric barre effect.In weaving, shade , variation.In knitted yarn, color variation.

About Mixing and Blending:Mixing: If different grade of same fibres are kept together , then it is called mixing. For example: 50% of 1 and 1/8 staple length of cotton + 50% of 1 ¼ staple length of cotton.

Types of mixing:1)Volume mixing2)Wt mixing3)Hand stock mixing

4) Bin mixing5) Mixing by hopper6)Lap mixing7)Card mixing8) Sliver mixing9) Automatic mixing

Blending: When different fibres of same or different grades are kept together, then it is called blending.

Objects of blending: To achieve uniform quality.To improve processing performance.To reduce and control of production cost.To meet function and end used requirement.Aesthetic i.e Fashion, texture ,drop luster etcTo give the required characteristics to the end product.To achieve effects by carrying color, fibre characteristics and so on.

Image of mixing and blending

Mixing Blending

About blow-room

Blow room is consist of number of number of machines used in succession to open and clean the cotton fiber to the required degree . 40% to 70% trash is removed in this section. Blow room section: A section in which the supplied compressed bales are opened, cleaned and blending or mixing to form uniform lap of specific length is called blow room section. The cleaning efficiency of blow room is 60%. This is the first section of spinning line for spinning the cotton yarn.

Blow-room

Operation in blow room

1) Opening2) Cleaning: To remove the dirt, dust.

Broken seeds, broken leafs , stalks and another materials from the fibers

3) Blending or mixing: To make good value of yarn and to decrease the production cost by mixing different grade of fibers.

4) Lap formation :a) To transfer the opened and cleaned fibers in to a sheet from of define width and uniform unit length which is called

Lap.b)To roll the lap of predetermined length is cylindrical shape around a lap pin.c) To transfer the lap from . The lap pin to a rod to suitable handle and feed it to substance processing carding machine.

Image of blow room operation