Method and appartus for forming a filter rod

Abstract

The present invention provides a method of forming a filter rod (R) of separated fibres and/or randomly oriented filter material fibres (F) for the tobacco processing industry, the method comprising: supplying separated filter material fibres (F) to an inlet (I) of a conveyor device ( 2 ), conveying the separated filter material fibres (F) along a process path (P) in a conveying direction (D) from the inlet (I) to an outlet (O) of the conveyor device ( 2 ), whereby a strand ( 4 ) of the filter material fibres (F) is formed along the process path (P), introducing at least one additive (A), especially a binder, to the strand ( 4 ) of filter material fibres (F) on the process path (P) in the conveyor device ( 2 ) at a position that is closer to the outlet (O) than the inlet (I), and consolidating the filter material fibres (F) into a filter rod (R) by wrapping the strand ( 4 ) of filter material fibres (F) with a wrapper material ( 6 ) after the strand ( 4 ) exits the outlet (O) of the conveyor device ( 2 ) in the conveying direction (D). Desirably, the at least one additive (A) is introduced or applied to the strand ( 4 ) of filter material fibres (F) proximate or adjacent to the outlet (O) of the conveyor device ( 2 ). The invention also provides an apparatus ( 1 ) for forming such a filter rod (R) of separated and/or randomly oriented filter material fibres (F).

1 . A method of forming a filter rod of separated filter material fibres for the tobacco processing industry, the method comprising:
 supplying separated filter material fibres to an inlet of a conveyor device,   conveying the filter material fibres along a process path in a conveying direction from the inlet to an outlet of the conveyor device, whereby a strand of the filter material fibres is formed along the process path,   introducing at least one additive to the strand of filter material fibres on the process path in the conveyor device at a position closer to the outlet than to the inlet, and   consolidating the filter material fibres into a filter rod by wrapping the strand of filter material fibres with a wrapper material after the strand exits the outlet of the conveyor device in the conveying direction.   
     
     
         2 . A method according to  claim 1 , wherein the at least one additive is applied to the strand of filter material fibres at or proximate to the outlet of the conveyor device. 
     
     
         3 . A method according to  claim 1 , wherein the conveyor device is a suction conveyor device comprising one or more suction members along the process path, wherein the step of introducing the at least one additive to the strand includes applying the additive to the strand of filter material fibres on the suction conveyor device. 
     
     
         4 . A method according to any of  claim 1 , wherein the step of introducing at least one additive is carried out within a final one-third of the process path defined by the conveyor device before the strand of filter material fibres exits the conveyor device. 
     
     
         5 . A method according to any of  claim 1 , wherein:
 the step of introducing at least one additive comprises applying the additive in a substantially fluid or liquid form by spraying, onto the strand of filter material fibres on the process path; and   wherein the additive is sprayed onto the strand at an angle of between 0° and 90° to the conveying direction.   
     
     
         6 . A method according to any of  claim 1 , further comprising locally moderating or reducing a vacuum or an under-pressure applied to the strand of filter material fibres in the conveyor device at or immediately prior to introducing the at least one additive thereto. 
     
     
         7 . A method according to  claim 1 , further comprising heating the additive before and/or during the step of introducing the at least one additive. 
     
     
         8 . A method according to any of  claim 1 , wherein the at least one additive comprises one or more of: an aqueous composition, a flavouring composition, a binder composition, a plasticizer, and an encapsulated compound or material. 
     
     
         9 . A method according to any of  claim 1 , wherein the step of introducing at least one additive comprises applying or delivering the additive to the strand of filter material fibres via a gaseous carrier, preferably compressed air or steam. 
     
     
         10 . A method according to any of  claim 1 , wherein the step of supplying the separated filter material fibres to the inlet of the conveyor device includes delivering a mixture of (e.g. different) loose, randomly oriented filter material fibres and optionally at least one particulate material to the inlet. 
     
     
         11 . An apparatus for forming a filter rod from separated filter material fibres for the tobacco processing industry, comprising:
 a conveyor device having a conveyor member for conveying separated filter material fibres along a process path in a conveying direction from an inlet to an outlet of the conveyor device, wherein the conveyor member is configured to create a continuous strand of filter material fibres from the separated filter material fibres supplied to the inlet;   a wrapping device for wrapping the continuous strand of filter material fibres in a wrapper material after the strand exits or emerges from an outlet of the conveyor device thereby to form a filter rod having a core of filter material fibres surrounded by the wrapper material; and   an additive application system comprising at least one applicator device, such as a nozzle, configured and arranged to apply an additive, especially a binder, to the strand of fibres at a position on the process path in the conveyor device closer to the outlet than the inlet.   
     
     
         12 . An apparatus according to  claim 11 , wherein:
 the at least one applicator device is configured and arranged to apply the additive by spraying at a position proximate or adjacent to the outlet of the conveyor device; and/or   wherein the conveyor device is a suction conveyor device and the conveyor member is a suction belt, wherein the filter material fibres are supplied to the inlet by an under-pressure or vacuum created by and/or in the suction conveyor device.   
     
     
         13 . An apparatus according to  claim 11 , wherein:
 the at least one applicator device includes a nozzle arranged or oriented at an angle of between 0° and 90° to the direction of the conveyor device; and/or   the nozzle is directed or extends substantially parallel to the direction of the conveyor member, preferably within a substantially horizontal plane; and/or   the nozzle is directed or extends substantially perpendicular to the conveying direction.   
     
     
         14 . An apparatus according to  claim 11 , wherein the additive application system comprises at least one supply or reservoir for each additive and optionally a carrier source, wherein each carrier source and each supply or reservoir is connected to said at least one applicator device, and preferably to each nozzle. 
     
     
         15 . An apparatus according to any of  claim 10 , further comprising one or more plate member in the conveyor device for locally moderating or reducing a vacuum or an under-pressure applied to the strand of filter material fibres at or immediately upstream of the at least one applicator device or nozzle; and/or
 wherein the additive application system comprises heating means for heating the additive before or during application in the conveyor device.   
     
     
         16 . The method according to  claim 3 , wherein the at least one suction device includes a suction belt. 
     
     
         17 . The method according to  claim 4 , wherein the step of introducing at least one additive is carried out within a final one-fifth of the process path. 
     
     
         18 . The method according to  claim 17 , wherein the step of introducing at least one additive is carried out within a final one-tenth of the process path.