Yarn manufacture I : Principle of Carding and Drawing

Carding and drawing are two fundamental process in yarn manufacture. Incarding the fibre tufts are opened , cleaned and separated thoroughly by fast moving pinned surfaces and then reassembled to form a nice 2D array of fibres which is subsequently transformed into an uniform sliver. Drawframe is essentially a stretching device for sliver used to improve mass irregularity of sliver and parallelization of fibresINTENDED AUDIENCE : Undergraduate students of Textile TechnologyPREREQUISITES : Nill

Week 1 :Objectives of carding process, carding actions , working principle of carding machine, Card feed system, lap and continuous feed systems, design
feature of taker-in/ licker-in,waste extraction, opening IntensityWeek 2 :Design feature of cylinder section, construction , design and working of flats, analysis of carding theory , carding force, fibre shedding, Transfer of
fibres from cylinder to doffer,Technological significance of doffing arc, doffing of web , web condensation, Package formation: Forms of packaging,
coiling, analysis of can driveWeek 3 :Motion transfer in card, draft and production calculations, card setting, significance of setting,Week 4 :Card clothing: licker-in, cylinder ,doffer clothing; card tooth geometry, Operational load on cylinder , fibre transfer efficiency, carding process,Week 5 :Autoleveller in card: principle of autolevelling, type of autoleveller, type of autoleveller, correction length, Fibre configuration in card sliver, mechanism
of fibre hook and nep formation, cloudy web, Drawframe:Fundamentals of drafting, draft , ideal drafting, geometrical analysis of fibre movement in
draftingWeek 6 :Objectives of drawing, Design features and working mechanism of drawframe. Drafting unit, drawing rollers, Drafting roller arrangement and its
significance , package formation,Autoleveller in drawframe, Sliver irregularity and its controlWeek 7 :Theory of drafting, Vasileff’s model of drafting, drafting wave, Drafting force , draft vs drafting force, Roller
setting: analysis of roller setting,influence of roller settingWeek 8 :Drawing process and its influence on fibre configuration in sliver, Draft and production calculation