Abstract: Fibre loosening device for a spinning unit of a spinning machine. The invention relates to a fibre loosening device for a spinning unit of a spinning machine. Before entering the fibre separating area, the sliver is longitudinally separated into fibre sections fed to a separating region, i.e., to helix-like arranged functional lines on the fibre separating roller, such feeding being non-simultaneous but sequential. The division into the fibre sections is initially carried out by means of protrusions defining grooves therebetween on a condenser, the axial distance between these grooves not being an integer multiple of the helix lead width of the functional lines on the fiber separating roller. The arrangement provides for reducing periodical irregularities of the fibres for the subsequent spinning process.