Sliver Quality Parameters
topic
Finisher draw frame sliver quality parameters: CVm% (2.0–3.5%, measured by Uster Tester), linear density (4–8 ktex for cotton ring spinning), fibre parallelisation (measured by AFIS fibre entanglement index), nep count (<100/g for carded, <50/g for combed, measured by AFIS), and short fibre content SFC(n) <18% for ring spinning. Sliver monitoring (online weighing on draw frame output rollers) provides per-can quality data.
Role
Sliver quality parameters define the starting condition for ring spinning. Each parameter has a direct, quantified effect on ring-spun yarn quality: CVm% of sliver feeds through the ring frame draft as yarn CVm% × draft attenuation factor; nep count in sliver predicts yarn nep count with approximately 70% pass-through rate. Building sliver quality specifications that guarantee target ring yarn quality requires understanding these transfer functions.