Rotor machine variables and yarn structure: Part IV - Influence of machine variables on configuration of neps and thick places of polyester rotor yarn

An increase in rotor speed and opening roller speed increases the unopened and fused neps. With increase in rotor diameter, the unopened neps first increase and then decrease but the hand-fused fibre neps decrease. Abraded neps do not show any trend with the change in machine variables. An increase in either rotor speed or opening roller speed increases the abraded-belt neps. Loose-belt neps invariably increase with the increase in rotor speed, opening roller speed and rotor diameter. With increase in opening roller speed at a particular rotor diameter, the surface-clustered thick places increase, but with the increase in rotor diameter, the surface-clustered thick places initially increase and then decrease. Abraded thick places increase invariably with an increase in opening roller speed and rotor speed.