Carding Machine

The carding machine individualises fibre tufts into single fibres, removes remaining impurities, eliminates short fibres and neps, and condenses the fibre mass into a uniform continuous sliver using a series of rotating cylinders covered with wire clothing (tooth density 400–900 ppsi, wire angle 10–20° for main cylinder). Key elements: licker-in (taker-in, 700–1,000 rpm, coarse wire clothing removing heavy trash), main cylinder (300–600 rpm, diameter 1,016–1,290 mm, wire clothing 800–900 ppsi), flats (flexible rotating card flat strips, 80–116 active flats, speed 200–400 mm/min — flat-cylinder nipping zone performs the principal carding and nep removal action), and doffer (20–40 rpm, condenses fibres into web for sliver formation). Modern flat cards (Trützschler TC 19i, Rieter C 80, Marzoli CM71) achieve production rates of 60–100 kg/hour at delivered sliver linear density 5–6 ktex (50–60 g/m) with CV% < 2.0%. Autoleveller on card doffer (open-loop or closed-loop, correction range ±25%, response time 0.1–0.3 seconds) maintains delivered sliver weight uniformity. Card wire clothing service life: 1,500–2,500 tonnes processed before regrinding (cylinder wire) and 500–800 tonnes (flat wire) — wire quality directly determines nep count and short fibre generation. AFIS online nep monitoring (Trützschler NEPCONTROL) measures neps per gram in real time adjusting flat speed and cylinder speed to maintain <80 neps/g.