CPC A24D 3/0233 (2013.01) [A24D 3/0279 (2013.01); A24D 3/04 (2013.01)] | 23 Claims |
1. A machine for making cigarette filters, comprising:
a forming beam having an internal channel extending along a main longitudinal direction and adapted to receive a tow of filter material impregnated with a plasticizing fluid, wherein the internal channel has a transverse cross section, the transverse cross section including a changing shape along the main longitudinal direction in order to impart a desired shape to the tow to form a continuous rod of filter material;
a porous conveyor belt to slide in the internal channel of the forming beam along the main longitudinal direction and to carry the tow along a feed path, the porous conveyor belt complies with the shape of the transverse cross section of the internal channel and being at least partly wrapped around the tow,
a treatment station located along the feed path and comprising a nozzle to blow a flow of steam into the internal channel transversely thereto,
wherein the nozzle comprises a plurality of planar sectors positioned transversely to the internal channel, the plurality of planar sectors defining a plurality of planar flow orifices, with each of the plurality of planar sectors defining a respective planar flow orifice placed directly in communication between a steam feed duct positioned around the respective planar flow orifice and the internal channel, with at least two of the plurality of planar flow orifices having different thicknesses along the main longitudinal direction, and
wherein the plurality of planar sectors are in mutual communication with each other, defining an uninterrupted planar flow orifice around the internal channel.
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