Rotor Spinning Overview
One common aim of unconventional spinning techniques is to exceed the performance of ring spinning. This is mainly achieved by separating the process of yarn formation from that of yarn winding on. One result is that the yarn can be wound on at higher speeds,
The Principle of OE Rotor Spinning
With many of these techniques the fibres from the draw frame sliver are resolved into Individual fibres in a processing stage prior to actual yarn spinning. In such cases the technique is generally denoted as Open End Spinning (OE Spinning).
Out of this segment, OE Rotor spinning (rotor spun yarns) is currently of special significance to circular knitting, besides ring spun yarns.
In this process fibres from the draw frame sliver supply are separated from one another 39 on an opening roller, taken over by an air stream, led through a fibre guide channel and fed to the rotor. In the revolving rotor housing the fibres lay themselves and form a ring. Out of this rotating ring the fibres are withdrawn in a plane more or less perpendicular to that of the fibre ring. The rotation of the rotor acts on the fibres in the form of twist when they just leave the fibre ring plane. This leads to a consolidation of the fibres amongst one another, i.e., to the formation of a yarn. This yarn is led away from the rotor area and is subsequently wound on a cylindrical bobbin to form a cross-wound package. The yarn obtains “real” twist. As a result of the fibre-yarn geometry during twist insertion the fibres do not have the idealized heliocoidal configuration as in a ring yarn. Every now and then fibres also coil themselves on the yarn across the longitudinal yarn axis. These places are called wrappers. A further reference is made to them later in a direct comparison between rotor and ring yarns.
Rotor spinning has established itself so far in short staple spinning. The accent lies here in the coarse count range (3 N, to 30 N, or 20 tex to 200 tex). Due to improvements in the technique and machine construction, combined with the use of combed slivers. count up to 42 N, are available in good quality. Even finer counts are not only being aimed at, but are also being presented to some extent.
In short staple spinning OE rotor spinning raises performance at this stage by about 5 to 6 times as compared to ring spinning.