a filtering apparatus for the filtering of fibers and equivalent material from flowing air , and in particular for use in textile operations , has been invented in which the fiber material is firmly compacted so that as much fiber material as possible may be accommodated in a given volume of a collecting container attached to the filtering apparatus . for this purpose the filtering apparatus has a hollow fiber filtering assembly into which the flowing air is guided , a conveyor screw and a motor to drive the conveyor screw toward an outlet of the filtering assembly . the filtering assembly also includes at least one filter , with the outlet located downstream in the direction of movement of the fiber material , and at least one braking component located near the outlet which serves to brake the motion of the fiber material induced by the conveyor screw and to compact the fiber material firmly .