UNIT I- Yarn, types, explanation, process
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UNIT I- Yarn, types, explanation, process
- 1. Dr. B. SANGEETHA PRIYA Assistant Professor
- 2. In the process, Cotton is separated from cotton seed and lint without damaging the fibres. Cotton is then measured for its moisture content, determining how much heat should be applied to open the fibres.
- 3. At this process the Fibers in Bale form will be loosen, opened and cleaned. Blending or Mixing: This is known as mixing when various cotton fibres come together during the spinning process. Alternatively, blending is combining different threads of the same grade. For example, cotton fibres are blended with polyester or wool fibres with polyester.
- 4. Lap formation- The opened fibres are made into a soft roll or lap or sheet by removing of waste particles. Aim to produce uniform yarns.
- 5. Carding is one of the most important operations in the spinning process as it directly determines the final features of the yarn. Opening the tufts into individual Fibers. Eliminating all the impurities which were not eliminated in the previous cleaning operations. Selecting the Fibers on the basis of length, removing the shortest ones. Removal of neps, then parallelizing and stretching of the Fiber. Transformation of the lap into a sliver, therefore into a regular mass of untwisted Fiber.
- 6. As a result of combing, the fibres are straightened to be arranged parallel to one another. A predetermined length of short fibres is removed from the long staple fibres. Neps are straightened or removed during the combining process.
- 7. Tasks of Draw frame Equalizing - Parallelizing - Blending Slivers are combined – smoothened & stretched. To reduce the weight /unit length of sliver to make it suitable for spinning system.
- 8. Yarn diameter is reduced to diameter of a pencil led. Bobbins are placed on roving frame where further drawing and twisting is done.
- 10. Incorporating twist -Winding into yarn at high speed
- 11. Yarn is “a generic term for a continuous strand of textile fibers, filaments, or material in a form suitable for knitting, weaving, or otherwise intertwining to form a textile fabric. Yarns play an important role in the fabric manufacturing process since a majority of the textile materials are constructed with yarns. Yarns are also used for products such as sewing and embroidery thread, string, and rope. Yarns are produced in various sizes and textures, and also vary in other characteristics.
- 12. Performance, end use, and fabric care are affected by yarn characteristics. Fibre length is used to broadly divide yarns into: –Spun yarns (made from short, staple fibres) –Filament yarns (made from continuous filament fibres) • Yarn processing methods for spun yarns are very different from those of filament yarns.
- 15. Spun yarn (Natural fibre) Filament yarn (MMF) Yarns are made from short length fibres. Eg: cotton & wool Yarns made from long and lengthy filaments Eg: Man Made Fibre Complex manufacturing process Least complication Various amount of twist is involved Usually very low or very high Twist Size is denoted by Yarn numbering Size is referred by a unit called Denier These are naturally absorbent Absorbency depends on the fibres used Warm, dull and fuzzy look. Lint, pilling, and easily stainable Smooth and lustre, does not have lint, pilling is seen, easily sheds off stain and cool Stretch depends on the amount of twist
- 16. SIMPLE YARNS SINGLE STRAND YARNS PLY-YARNS CORD OR CABLE YARNS DOUBLE YARNS NOVELTY YARNS SLUB YARNS FLAKE YARNS FLOCK YARNS SPIRAL YARNS RETINE YARNS BOUCLE, LOOP, CURL YARNS KNOB, KNOT, SPOT YARNS GRANDRELLE YARNS CHENILLE AYRNS TWEED YARNS TEXTURED YARNS YARN S SKETCH YARNS HEAT SET THERMOPLASTIC YARNS ELASTOMERIC YARNS BI-COMPONENT YARNS BI-CONSTITUENT YARNS CHEMICAL TREATED NATURAL-FIBRES BULK YARNS HIGH BULK YARNS LOOP BULK/ AIR JET YARNS
- 17. Simple yarns are characterized by uniform size and regular surface. They can be broadly divided into single, ply, cord, and rope yarns based on construction. 1. Single yarn is the simplest type of yarn. It is commonly produced by twisting together staple or filament fibres. 2. Ply yarns are produced by twisting two or more single yarns. Each strand of single yarn is referred to as a ply. Thus, four single yarns twisted together would form a four-ply yarn. 3. Cord yarns are produced by twisting two or more ply yarns. 4. Rope yarns are produced by twisting two or more cord yarns.
- 20. Carded and combed yarns: Cotton • Carding is cleaning of fibers to remove the short unwanted fibers – carded yarn • Combing is additional step when helps in getting better (high quality) yarns – combed yarn Woolen and worsted yarns: Wool • Woolens are made in a specific way of preparing a fiber –good quality Worsted yarns are made by random placing and making a yarn. Fibers of uneven length are made into a yarn – medium quality
- 21. Novelty yarns, typically made of two or more stands, are produced to provide decorative surface effects. Based on the purpose, each strand is referred to as base/core,effect, or binder. These are parts of fancy yarn. -The base/core strand provides the structure and strength. -The effect strand creates decorative detail such as knots and loops. -The binder is used to tie the effect yarn to the base yarn if binding is necessary. There is a wide variety of novelty yarns that are produced using different techniques and types of fibres and strands.
- 23. They are intentionally created to have distorted or irregular surface Novelty yarns are used for decorative purpose These are generally not durable but used to create different textures There are many ways to create fancy yarn Different coloured fibre - can be blended together than spun as one yarn Colour - dyeing or printing Spots of coloured fibre - twisted into the base yarn Two or more threads of different softness, thickness, weight, colour, fibre content can be twisted together Raised texture can be introduced by controlling the amount and direction of twist
- 25. Slub yarns can be either single or ply yarns. These yarns are characterized by the soft bulky area that is spun at regular or irregular intervals.
- 26. Flock/flake yarns have small tufts of different colored fibres added at intervals. These tufts can be easily pulled out. Flock/flake yarns are generally single yarns.
- 27. Nub, knot, and spot yarns are ply yarns in which the effect yarn is twisted around the base yarn to produce a thicker area or a bump.
- 28. Spiral and corkscrew yarns are ply yarns in which one ply is soft and thick and the other is fine.
- 29. Bouclé and loop yarns are ply yarns that use three sets of yarns – base or core yarn, effect yarn, and tie yarn.The effect yarn is looped around the base or core yarn and tied with a binder yarn.
- 30. Chenille yarns are pile yarns that are often made by slitting leno weave fabrics into narrow strips in the warp direction.
- 31. Textured yarns are made of fully drawn filament fibres with a changed surface, shape and texture developed by using the new spinning techniques. Nylon and polyester are two main fibres that are textured. Textured yarns provide many variations in fabric properties. There are two main types of textured yarns: 1. Stretch yarns 2. Bulk yarns
- 32. Stretch yarn can be made by using any of the following methods: 1. By using special heat setting treatment filament fibres such as nylon and polyester. 2. From elastomeric fibres. 3. From bi-component fibres. 4. From bi-constituent fibres. 5. From chemically treated natural fibres.
- 33. Bulk Yarns are softer and much pliable then tightly constructed twisted yarns. Bulk yarns are also have a better cover. They create a less transparent fabrics and are of two types: 1. High bulk yarns 2. Loop-bulk or airjet yarns
- 34. THANK YOU