Objectives of ginning, Study of working of different gins – Knife roller gin, Saw gin. Ginning out-turn. Effect of ginning performance on yarn quality – Power requirement in ginning.
Objectives of blowroom. Principle and description of Opening, Cleaning and Blending machines. Concepts of Opening intensity and Cleaning efficiency. Settings and speeds of various Openers/cleaners. Sequence of machines in modern blowroom line. Blowroom line for cotton and man-made fibres and their blends. Dust extractors, Filters, Waste collection. Mechanism of lap formation, Chute feed. Power requirement in blowroom.
CARDING
Objectives of carding. Basics of Opening, Cleaning and fibre individualisation. Study of working of semi high production, high production cards. Speeds and setting of functional elements. Concept of auto levelling in carding. Drives, Card clothing and Production calculation. Concept of Cylinder loading and the factors influencing it. Latest developments in carding to increase production and sliver quality.
DRAWFRAME
Basic principles of doubling and drafting. Description of working of various drafting systems. Concept of roller flutes, roller setting, roller pressure, web condensation and roller lapping. Study of stop motions. Draft and production calculation. Effect of roller defects, roller setting, roller pressure, break draft and draft distribution on sliver quality. Process parameters for processing cotton, man-made fibres and blends. Working of autoleveller on drawframe. Developments in drawframe machines. Influence of drawframe sliver quality on yarn characteristics.
COMBER
Requirement and objectives of comber preparatory process. Methods of lap preparation – lap doubling process, sliver doubling process, their merits and limitations. Objectives and principles of combing. Working of comber – sequence and timing of operations in combing. Types of feeding – concurrent feed and counter feed, Degree of combing. Combing efficiency. Concept of piecing waves, asymmetric web condensation. Comber waste in relation to pre-comber draft, direction of fibre hooks, type of feed, top comb setting. Settings and production calculation. Determining optimum level of comber waste for different mixings and yarn counts. Introduction to modern combers.
SPEEDFRAME
Objectives of speedframe. Principle of working of modern speedframe. Differences between bobbin lead / flyer lead roving processes. Mechanism of winding and bobbin building. Settings and speeds. Draft, twist and production calculations. Effect of roller setting, roller pressure, apron spacing on roving quality. Importance of roving quality on ringframe performance and yarn quality.
REFERENCE
Text Books
1. Klein W., Vol. 1-3, “The Technology of Short Staple Spinning”, “A Practical Guide to Opening & Carding” and “A Practical Guide to Combing, Drawing, and Roving frame”, The Textile Institute, Manchester, U.K., 1998.
2. Chattopadhyay R. (Ed), Advances in Technology of Yarn Production, NCUTE, IIT Delhi, 2002.
Reference Books
1. Chattopadhyay R., Technology of Carding, NCUTE, IIT Delhi, 2003.
2. Chattopadhyay R. & Rengasamy R., “Spinning, Drawing, Combing & Roving, NCUTE Pilot Programme.
3. Salhotra K. R. & Chattopadhyay R., Book of papers on “Blowroom and Carding”, IIT Delhi 1998.
4. Duraiswamy I, Chellamani P & Pavendhan A., “Cotton Ginning” Textile Progress, The Textile Institute, Manchester, U.K., 1993.
5. Lord P. R., Yarn Production: Science Technology and Economics”, The Textile Institute, Manchester, U.K., 1999.