Md.Shahjalal Lecturer.CTEC Introduction to Yarn Manufacturing ‘Yarn: Yam is a linear assembles of continuous often plied twisted or without twisted composed of either natural or ‘man-made fibers or filaments suitable for weaving and knitting to form cloth, Classification of Yarn: Yarn may be classified according to: 1 Length of fiber Process Sequence of Manufacturing a. Spun Yarn a. Carded Yarn b. Filament Yarn b. Combed Yam 3, Formation of Yarn or System of twist insertion 4, Use of yarn a. Ring Yarn a. Woven yam i Compact yarn i ‘Warp yan ii, Siro Yam ii, Weft yarn . Rotor Yarn b. Knit yarn ©. Vortex Yarn d. Airjet yarn 5. Type of fiber used 6. Number of Strand used a. Single fiber: 100% cotton yarn, 100% jute a. Single Yarn yarn, 100% polyester yarn. b. Ply yarn b. Multifiber/blend yarn: P/C or TIC, CVC c. Cable yarn yarn Definition of Different Yarns Spun Yarn: Spun yar is defined as the twisted continuous strand of staple fiber having considerable strength. Spun yarn is formed by flyer, ring, rotor, air-jet, vortex spinning system, Filament Yarn: Filament yam is defined as the twisted or without twisted strands of filaments, where each filament runs through the whole length of yarn. When yarn is composed of one filament is called monofilament yar. If yarn is composed of more than one filament is called multifilament yarn. There are approximately 50 to 100 filaments present in one multifilament yarn, Carded Yarn: Yarns produced from fibers that have been only carded but not combed. Combed Yarn: Yam produced from fibers that has been both carded and combed, Normally combed yarn is ‘manufactured by ring spinning system. The combing process is an additional step beyond carding. In this process the fibers are arranged in a highly parallel form, and additional short fibers, neps and trash are removed producing high quality yam with excellent strength and evenness. Normally combing is necessary for producing good quality fine yar. Ring yarn: Ring yam is formed by the twisting of ring and traveler combination by ring spinning machine. Normally ring yarn can be coarse to fine in fineness Rotor Yarn: Rotor yar is formed by the twisting of rotor by rotor spinning machine. This yarn can be formed from short fiber. Normally rotor yarn is coarse. rotor yarn is also called open end yarn. Air Jet Yarn: Air Jet Yarn is manufactured by air jet spinning machine, This yarn is false twist or zero twist yarn, This yarn is coarse to medium in fineness. Vortex Yarn: Vortex yam is manufactured by vortex spinning machine. This yam is coarse to medium in fineness. Vortex yarn is also open-end yarn.Md.Shahjalal Lecturer.CTEC Woven Yarn: The yam is manufactured for the purpose of woven cloth manufacturing is called woven yarn. If the yarn is used lengthwise of cloth is called warp yarn and if the yarn is used widthwise direction is called weft yarn. Normally warp yarn is stronger than weft yarn. Knit Yarn: Yarn which is manufactured for the purpose of knitted cloth manufacturing is called knit yarn. Knit yarn is low twisted soft yarn. Single yarn: Single yarns are made from single filaments or group of staple or . — filament fibers twisted together to form the desired yarn. Monofilaments, Single Strand ‘multfilament and spun yarns are all single yarns, ie 20s Ne, 30s Ne, 40/1 Ne, agree SO/1 Ne yarn. Ply yarn: Ply yarns are made by twisting together two or more single yarns. ae Each part of the yam is called a ply. Yam can be two, three or four plied. Plied Yarn aaa Cord Yarn: ‘The yarns are formed by twisted together of plied yarns. They are ea, ; pecurea seldom used in conventional fabrics z eve: 100% Cotton Yarn: The yarn has 100% cotton fibers Cord PIC or T/CPolyester/Cotton or Terelyne/Cotton): Yan produced by blending of cotton and polyester fibers. The maximum part of this yam is polyester ie the yarn has more than 50% polyester fibers and the rest portion is cotton. CVC(Chief Value Cotton): A blended yam having more percentage of cotton as compared to that polyester is called CVC yarn, For example, Cotton: Polyester 70:30, Cotton: Polyester 80:20, Cotton: Polyester 60:40 ete. Some Special Yarn: Instead of these above yarns, there are also many yarns, which are formed by special way with special character for different extra ordinary purpose. The name of some special yarns is © Mixture or Ingrain yarn © Slub Yarn © Chenile Yarn © Melange yarn + Knop yarn + Crepe yarn * Loop Yarn + Loop yarn © Glitter Yarn Siro Yarn Stub Yarn Chenile Yarn Loop Yarn Melange Yarn Spinning/Yarn Manufacturing: Spinning may be defined as the art or techniques to produce yarn by twisting of fibrous materials or any other method from the fiber forming agents. Spinning is the first step in the textile ‘manufacturing process.List of various Conventional and Modern Spinning Method: Md.Shahjalal Lecturer.CTEC Conventional Male Spinner Flyer Spinner Cap Spinning Machine Centrifugal Spinning machine Pot Spinning machine Ring spinning machine Modern Rotor Spinning AirJet Spinning Air Vortex Spinning, Friction Spinning, Wrap Spinning Self Twist Spinning Process Sequence of Carded Yarn Productio Input/Feed Material Cotton Bales > Selected Cotton Bales Lab/Opened flock Cotton > Card Sliver . Drawn Sliver - Roving - Carded yarn (small ring > cops) Carded yarn cone > Process Name Bale Management L Blow-room 4 Carding + Drawing 4 Simplex 4 Ring Spinning 4 Winding 4 Conditioning Process Sequence of Combed Yarn Production: Input/Feed Materi Cotton Bales = Selected Cotton Bales Lab/Opened flock Cotton > Card Sliver = Drawn Sliver - Mini Lap = Drawn Sliver = Roving > Combed yarn (small ring cops) > Carded yarn cone — Process Name Bale Management 1 Blow-room 1 Carding + Pre-Comb Drawing Lap Former 1 Comber Simplex t Ring Spinning L Winding t Conditioning Output or Delivery Product Selection of Bales, Lap/Opened flock cotton Card Stiver Drawn Sliver Roving Carded Yarn (small ring copes) Carded Yarn (large package Cone) Conditioned and twist set yarn in cone ‘Output or Delivery Product Selection of Bales, Lap/Opened flock cotton Card Sliver Drawn Sliver Comber Lap/Mini Lap ‘Combed Sliver Roving Combed Yarn (small ring copes) Carded Yarn (lange package Cone) Conditioned and twist set yarn in coneCotton Fiber ‘Yarn in Bobbin (Small Package) Difference between combed yarn and carded yarn: Blow Room Lap Roving Yarn in Cone (Large Package) ST ‘Carded Yarn Combed Yarn 1 | The yarn that is obtained without combing process | The yarn that is obtained including combing process is, is termed as carded yarn. termed as combed yarn. 2 | Quality of carded yam is not better than combed yarn. | Quality of combed yarn is better than carded yarn. 3 _| Short fiber percentage is higher. Short fiber percentage is lower 4 | Normally, carded yarn strength is lower than ‘Normally, combed yarn strength is higher than combed combed yarn of the same count. am of the same count. 3_| More hairiness ‘Less Hairiness 6 | Less Luster More luster 7 | Fabric made of Carded yarn is less gentle against | Fabric made of Combed yam is gentle against the skin the skin 8 | Carded yarn is cheaper than combed yarn. Combed yarn is costlier than combed yarn.Md.Shahjalal Properties of Cotton Fiber Considered by a Spinner: Fiber length & length uniformity. Fiber strength & elongation. Fiber fineness. Fiber maturity. Fiber cleanliness. Fiber color. Fiber stiffness, Some chemical deposits. Fiber Length: The average length of spinnable fiber is called staple length. Higher the staple length better the yarn quality. Fiber with length of 15-50 mm is preferable for yarn manufacturing Influences of fiber length in yarn production & Quality: |. Productivity: * Long fiber increase production & quality * Higher amount of short influence fiber End breakage, increase quantity of waste, increase Production & Quality. 2. Yarn Strength: Short fiber reduces yarn strength. 2. Yarn Evenness: Short fiber causes yarn unevenness Yarn Hairiness: Short fiber causes yarn hairiness. Besides, fiber length has influence on — © Spinning limit © Handle of the product. © Luster of the product. Fiber Strength: Fiber strength is very often the dominating characteristic. The maximum strength for a fiber is Approximately 60 CN/Tex. Normally the breaking strength of cotton is 15-40 CN/Tex. Very weak cotton fibers are to be avoided because cotton will rupture during processing both in the blow room & carding causes creation of short fibers & deformation in yarn strength & uniformity Except for polyester, fiber strength depends on moister content for linen, cotton ete, Fiber strength increases with increasing moisture content, while the reveres happen in case of nylon, viscose ete fibers. Some significant breaking strength of fibers, 35-60 CN/Tex. wentess is another important characteristic of fiber. The fineness determines how many fibers are present in the cross section of a yar of a given thickness, Minimum 30 fibers are needed at the yam X-section, but there are usually over 100, Now a day this is the minimum value. Fiber fineness primarily in fluenciesMd.Shahjalal ‘© Spinning limit © Laster ‘© Yarn evenness. © Handle ‘© Yarn fullness. + Productivity Fiber Maturity: of the moisture swollen fiber represents 50-80% of the round X-section as unripe when it represents 30-45 % cotton fiber consists of cell wall & lumen, Fiber is to be considered as ripe when the cell wall dead when it represents less than 25%. Immature fiber causes, 1. Loss of yam strength, Neppiness. A high proportion of short fiber. Varying dye ability Processing difficulties mainly during carding, pRep Fiber Stiffness: Fiber stiffness plays a significant role mainly during rolling, revolving & twisting movements. A sti fiber cannot properly bound into the yarn, as a result it causes hairiness. Fiber those are not stiff enough cannot maintain its shape after deformation, In most of the cases this reason leads, to formation of neps. The “Slenderness Ratio” can serve as a measure of stiffness. Slendemess Ratio = (Fiber Length/ Fiber Diameter) So, when slenderness ratio is high, then the stiffness is low Fiber elongation: Textile fiber should have at least 1-2% elongation characteristics and preferably slightly more. They must be able to deform in order to width stand high loading but it also has to return to its original shape. Cotton & wool fiber have 6%-10% & 25%-45% elongation characteristics respectively. For normal textile goods higher elongation property is neither necessary nor desirable. They make the processing in the spinning mill more difficult especially during “Drawing Operation”. Fiber Cleanness: In addition to usable fibers, cotton stock contains foreign matter or trash or foreign materials of various kinds: - + Vegetable Matter: Husk portions, Seed fragments, Stem fragments, wood fragments. © Mineral Materials: Earth, Sand, dust, coal. + Others: Metal fragments, cloth fragments, packing materials, etc. Foreign matter causes: Drafting disturbance. + Yan Breakage. Filling up of card clothing + Contaminated yarn Color of fiber: Color gives an indication of the fibers ability to accept dyes in manufacturing process. Generally, the color of cotton fibers is, Extra white, White., Spotted, Tinged, Yellow stained, The color of cotton is determined by the degree of reflectance (Ra) & yellowness (+b) in the HVI. Reflectance indicates how bright or dull a sample is, and yellowness indicates the degree of color pigmentation.Chemical Deposits: The best-known sticky substance of cotton fiber is “Honey Det Other chemical deposits are- Sugar, Wax, Oil, Fat & some other synthetic substances, During spinning of sticky cotton, however the relative humidity of the air in production area should be held as low as possible, Mixing & Blending Mixing: When same kind but different grades of fibers are mixed together at different ratio then it is termed as mixing. eg. Low grade Cotton+ High Grade Cotton, 50% Egyptian Cotton+50% China Cotton, 50% Pima Cotton+50% Giza Cotton, 50% 1 1/8” staple length cottont 50% 1 14” staple length cotton ete Blending: When different fibers of same or different grades are kept blending. eg_Nylon+Cotton, Cotton+Polyester, PC/TC, CVC 80/20, CVC 60/40. ther at different ratio then it is termed as Objectives of Mixing and Blending in Spinning: + Blending and mixing influences the reduction of the final product through blend composition, availability of fiber quality and inherent fiber properly variations. ‘+ Mixing and blending is used to provide required features to the end product. + Itis used to control and decrease of yarn production cost. ‘+ Itis used to achieve uniform quality of yarn. + Ithelps to meet functions and end used requirement. ‘+ Incorporate aesthetic features like texture, luster, drape, fashion etc. © Mixing and blending is used to develop yam processing performance. ‘+ Also used to achieve different effects by carrying color and so on. Various types of Mixing: i) Volume mixing ii) Weight Mixing iii) Hand Stock Mixing iv) Bin Mixing v) Mixing by hopper vi) Lap Mixing vii) Card Mixing viii) Sliver mixing ix) Automatic mixing Volume Mixing: Here, volumetric mixing is performed. Cotton fibers of different quality falls into the mixing bin and bins are filled in different volume by pneumatic air. Thus, mixing is done. Weight Mixing: In weight mixing, different quality of cotton fibers are weighted at first and then are mixed in different weight. Hand Stack mixing: This method is old type of mixing, Normally used to produce higher count yarn. This mixing is done entirely by help of hand. Bin In bin mixing, Cotton flocks are transferred from the bale opener into pipe line. The pipe dia is 10” and is passes over the bins, fiber flocks are delivered into bins from the delivery boxes of the pipe placed in the pipe.Md.Shahjalal Lecturer.CTEC Lap Mixing: In Lap mixing, double scutcher is used. One is breaker scutcher & another is finisher scutcher. Different grade and different quality laps are produced in breaker scutcher. Four lap stands are placed before the finisher scutcher for feeding four laps. Therefore, mixing can be done different ratio like 1/3, 1/1, 3/1 etc. Automatic Mixing: In this method cotton fibers are mixed automatically by different automated machines without breaking bales manually, Here the numbers of bales are placed both side of the machine longitudinally. The machines move in traversing motions and extracts the fibers from the bales into the duct mixing for example unimix of Reiter. Card Mixing: This mixing together. Sliver Mi draw frame. Mixing by hopper: In this method, at first cotton fibers are passed into the bale breaker from where the fibers fall on a lattice. A series of lattice take the cotton fibers of different quality into the mixing bins through a cross lattice. Asa result, mixing of different cotton fibers are performed. sometimes used in the high production carding where two laps are fed and mixed ig: In this method different carded slivers are used in a particular ratio by doubling to mix the fibers in Points to be considered during Mixing & Blending + Similarity in fiber length ‘+ Strength of fiber + Similarity in color of fiber ‘= Maturity of fiber + Skilled labor ‘+ Well equipped machines used. Difference between Mixing and Blending SL | Mixing Blending 1 | Same kind but different grades of fibers are | Different fibers of same or different grades are kept mixed together at different ratio together at different ratio 2 [Different properties of same fiber are | Same properties of fibers are used, considered in mixing. 3__[ In mixing quality of fibers are considered, In blending. quality of fibers is not considered. 4 | Cost reduction is the main objective of mixing. 5 | All the characteristics of fibers are not correctly known in this process. Properties and quality of final product is the main objective of blending. All the characteristics are known in this process. 6 no particular ratio of fibers to mix | There must be a particular ratio of fibers to mix with with each other. each other. 7__| Itis costly process. Itis cheap process than mixing. 8 | Example: Low graded cotton + high graded | Example: 35% polyester + 65% cotton = BlendingMd.Shahjalal Lecturer.CTEC Bale Management: Testing, sorting & Mixing bales according to properties of fiber for producing specific quality yarn at minimum cost is called “Bale Management” Objective of bale management: ‘+ Anevening out of the quality characteristics of a yarn, + A means of avoiding quality jumps. ‘+ A possibility of reducing costs, as a result of an improved knowledge of the fiber characteristics. Automatic Bale Opener of Rieter