Principles of Combing, Roving Preparation & Ring Spinning

The course will focus on three processes i.e. combing , roving preparation and ring spinning. The construction , design features and working principles of the machines will be looked into. The role of machine and process parameters on process performance will be explained. The interaction between technology and machine design will be discussed. Emphasis will be on “know why” rather than “know how”.INTENDED AUDIENCE: Undergraduate students of Textile TechnologyPREREQUISITES: Nil

Week 1: Flow chart of combed spinning process, objectives of combing , consequence of short fibres in cotton , segregation principleof short fibres from longer ones, Combing operations and its classification, sequence of operation, Timing diagramWeek 2: Pre-combing operation, Comber lap formation, Design features and working principle sliver lap & ribbon lap machines, Draft and its influence on lap quality. Structure and design feature of combing machine. Working principle , Design features of combing machine elements ( lap feed roller, cylinder comb, top comb, nipper assembly, detaching roller, sliver table, drafting rollers, coiling arrangement)Week 3: Mechanism for lap feed, nipper assembly movement, detaching roller movement, and cylinder comb Web structure , condensation, sliver guidance & drafting processWeek 4: Theory of noil extraction fro forward and backward feed machines, Influence of process parameters on combing efficiency Productionand draft calculation Week 5: Objects of roving frame, Machine configuration, working principle Drafting system, drafting elements (cradle, aprons, condenser etc.)Week 6: Flyer construction, presser , twisting , flyer top , twist diameter count relationship Bobbin geometry , Operation for bobbin building,Winding process, winding equation, Bobbin leading vs flyer leading frameWeek 7: Variable speed drive, Differential gear Building motion: function and workingWeek 8: Drive analysis, motion flow,Ring frame : machine configuration, various components, working principleWeek 9: Drafting, Drafting elements, drafting angle, Difference between speed frame and ring frame drafting system, break draft and main
draftdistribution Twisting and winding principle, twisting winding equation, twist flow, winding tensionWeek 10: Bobbin building : bobbin geometry, Nature of ring rail movement, winding and binding layer, Formation of base and conical bottom. Ringand traveler: types , purpose, traveler numberWeek 11: Spindle : construction, drive, Spinning geometry, spatial location of elementsWeek 12: Balloon mechanics, Tension in balloon yarn, balloon size, End breaks, non uniformity, causes & remedies