Abstract: In a machine for making cigarette rods containing two types of tobacco there is provided a dual hopper (1200) for containing the two types of tobacco separately and a conveyor (1206) to transport the tobaccos side by side to a chute (1203) and then to a carding area (1214). The levels of the tobaccos in the carding area are monitored and if one is too high then an appropriate flap (306,308) in the chute is opened and that type of tobacco is diverted and recycled to the hopper (1200) until the level of that tobacco in the carding area has returned to an acceptable level, whereupon said flap is closed and that type of tobacco is able to re-enter the carding area.

Abstract: A filter for a smoking article employing a resilient valve assembly in the path of the smoke. The valve assembly being movable in a first position in which the flow ventilating air is permitted and a second position in which the flow of air is prevented. The valve assembly being resiliently biased towards the first position and being displaceable towards the second position when a particular pressure differential is exceeded.