10. YM-2012 Card objectives n working principle.pdf
- 1. Pre Spinning Processes (YM-2012) M Irfan Department of Textile Engineering National Textile University Faisalabad Reference: The Rieter Manual of Spinning
- 2. Yarn manufacturing process flow Lap or opened fibers Sliver Roving Ring bobbin
- 3. What is carding • The conversion of tufty material into a single fiber state (filmy web) by passing it between two surfaces containing wire points or saw tooth is called carding. M Irfan, PhD • Machines used to carry out this work are called cards • Two famous saying about carding demonstrate the importance of carding process in the yarn manufacturing • “Card is the heart of spinning” • “well carded half spun”
- 4. Different types of card machines • One classification is • Revolving flat card • Mostly used in ring spinning • Roller card • 3-4 inch diameter rollers instead flats • Another classification is • Single card • Used in ring spinning • Double or tendem card • Improved quality and blending M Irfan, PhD Tendem card Single revolving flat card
- 5. M Irfan, PhD Roller card Revolving flats card card
- 6. Objectives of carding • Fiber-to-fiber opening • Fibers need to be opened to individual fiber level for cleaning • Blowroom opens material to tuft level (very small tufts) • Carding action opens the material to individual fiber level • Elimination of impurities • Foreign matter or impurities are removed at card • Impurities mainly drop in taker-in region, only small amount is removed in flat strippings or drop at other positions • High degree of cleaning can be achieved at card (80-95 %) • 95-99 % impurities can be removed both by blowroom and card • 0.05-0.3 % impurities can still be present in card sliver M Irfan, PhD
- 7. Objectives of carding • Elimination of dust • Card is a good dust removal machine • Card can remove dust particles attached firmly with fiber surfaces • Free dust removal also takes place as in blowroom • Significant fiber/metal and fiber/fiber friction is present in card • Neps removal or disentanglement • A mass of entangled fibers is known as nep • Neps increase in blowroom from machine to machine • Due to rolling of fibers during transportation • Neps are unentangled at card • Small amount of neps are removed in flat stripping M Irfan, PhD neps
- 8. Objectives of carding • Neps removal or disentanglement • Factors affecting disentanglement at card • Low fiber density at cylinder (larger cylinder width) • Closer setting between different clothing surfaces • Sharper clothing • Optimal speed of take-in (not too low) • Low doffer speed • Low production or throughput M Irfan, PhD
- 9. Objectives of carding • Removal of short fibers • Short fibers are removed in flat strippings at card • Card removes 1-2 % flat strippings. Half of these strippings are short fibers • Thus card removes less than 1 % short fibers from raw material which is not noticeable in staple diagram • Short fibers are removed if they are pressed in clothing • Longer fibers have more contact with cylinder clothing, they are carried with cylinder • Short fibers have less contact with cylinder clothing, they are caught in flat clothing and are pressed into flat clothing and are carried away M Irfan, PhD
- 10. Objectives of carding • Fiber blending • Short term fiber blending takes place on card • Long term blending is not possible because fibers spend short time in card • Transverse blending and fiber to fiber blending is achieved • Fiber orientation • Longitudinal orientation of fibers takes place on card machine • Fibers are more parallel on cylinder but less parallel on doffer due to formation of web • Partial longitudinal orientation is obtained but not perfect orientation M Irfan, PhD
- 11. Objectives of carding • Sliver formation • Formation of sliver takes place on card • Sliver is the first intermediate product that is formed during yarn manufacturing • Sliver is a thicker linear strand of fibers which is untwisted M Irfan, PhD
- 12. Objectives of carding • Fiber to fiber opening • Elimination of impurities • Dust removal • Short fiber removal • Fiber blending • Fiber orientation • Sliver formation M Irfan, PhD
- 13. M Irfan, PhD 1 Conveying duct 2 Feed Chute 3 Transport Roller 4 Feed Roller 5 Taker-In/ licker-in 6 Knife Grid 7 Suction duct 8 Cylinder 9 Front Carding Segment 10 Flats 11 Cleaning Unit 12 Post carding segment 13 Cylinder cover plate 14 Doffer 15 Stripping Device 16 Calender Roller 17 Can 18 Coiler
- 14. Working of a card machine • Raw material supply into the chute feed (2) via ducts (1) • Compressed batt is formed • Transport roller (3) feed the batt to the feeding arrangement (4) (feed roller and feed plate) • Feed assembly feeds material to taker-in (5) • Taker-in opens the fibers, pass them overs grids (6) and transfer them to the main cylinder (8) • Impurities liberated at taker-in and card segments (9) are removed by suction duct (7) • Carding process takes place between cylinder and flats (10) and fibers are opened to individual level M Irfan, PhD
- 15. Working of a card machine • Cleaning assembly (11) removes fibers, neps and trash from flats • Grids or cover plate (13) is present under the cylinder • Opened and aligned fibers on cylinder (9) are taken by doffer (14) in the form of web • Stripping unit (15) removes web from doffer and convert it into sliver • Calendar roller (16) compress the sliver and coiler (18) deposits the sliver in cans (17) M Irfan, PhD