Abstract: A filter-manufacturing apparatus comprises a cutting drum, which has transporting grooves and adapted to receive filter rods having a prescribed length. An annular slit is formed in the circumference of the cutting drum. A circular cutting blade extends into the annular slit in a rotatable manner. A rod-shaped stopper is movably arranged in each transporting groove, and the distance between each stopper and the annular slit is adjustable such that it corresponds to the length of a filter plug to be cut from a filter rod. The cutting drum comprises a pushing mechanism for moving the filter rod along the transporting groove against the stopper by jetting air, whereby the filter rod is cut by the cutting blade, with its one and abutting against the stopper. A receiving drum with receiving grooves is in rolling contact with the cutting drum. The receiving drum rotates such that the receiving grooves come into alignment with the transporting grooves of the cutting drum.

Abstract: A tobacco filter manufacturing apparatus for making filter rods added with additives therein. A length of filter material is held between a conveyor system and a mask ring to be fed into a predetermined direction. The conveyor has laterally extending air permeable sections and air non-permeable sections; the mask ring has laterally extending slits and mask sections between the slits. The air permeable sections of the conveyor and slits in the mask ring are set in registry with each other. The conveyor and mask ring are synchronously driven. Within the mask ring is provided an additive supplier while the conveyor is provided with a negative pressure source such that the additive is adsorbed through the slits onto the filter material under the negative pressure behind the filter material through the air permeable sections of the conveyor.