Method and apparatus for producing filter rods

摘要

The invention relates to the production of filter rods by the extrusion method, perforations being introduced into the wrappings of the filter rods. The perforations reduce the air resistance of the wrappings at those points on the filter rods at which subsequently, in the production of ventilated filter cigarettes with these filter rods or parts thereof, connecting sheets are provided with perforations in order to allow a secondary air flow to enter the inside of the filter tips. <IMAGE>