Methods and Apparatuses for Manufacture of Smoking Article Filters

Abstract

An apparatus for manufacturing a filter rod for a cigarette or other smoking article having a pattern formed in relief on the outer surface thereof. The apparatus comprises a passage including a portion configured to receive and compress filter material to form a filter rod and a belt extending along the passage to convey filter material through the passage. The apparatus includes a patterned relief surface configured to impress a relief pattern on a surface of a filter rod as it is formed within the passage.

1 . An apparatus for manufacturing a filter rod for a cigarette or other smoking article having a pattern formed in relief on the outer surface thereof, the apparatus comprising:
 a passage including a portion configured to receive and compress filter material to form a filter rod; and   a belt extending along the passage to convey filter material through the passage;   wherein the apparatus includes a patterned relief surface configured to impress a relief pattern on a surface of a filter rod as it is formed within the passage.   
     
     
         2 . An apparatus according to  claim 1  wherein the relief surface is formed on the belt such that the belt engages the filter material and impresses the relief pattern on the surface of the filter rod as it passes through the passage. 
     
     
         3 . An apparatus according to  claim 2  wherein the belt comprises a plurality of plates hingedly coupled end-to-end. 
     
     
         4 . An apparatus according to  claim 3  wherein the front and rear edges of each plate which are hingedly coupled to the adjacent plates, are formed with a corresponding tessellating and/or saw-tooth configuration. 
     
     
         5 . An apparatus according to  claim 3  or  claim 4  wherein the hinged connection between the plates comprises a flexible cord or a plurality of hinge pins. 
     
     
         6 . An apparatus according to any of  claims 3 - 5  wherein the belt is driven over a plurality of guide rollers, wherein at least one of the guide rollers has a faceted outer surface and the belt is in registration with the at least one guide roller such that the plates of the endless belt lie flat on a facet of the at least one guide roller as the belt passes over said guide roller. 
     
     
         7 . An apparatus according to  claim 2  wherein the belt comprises a flexible band with a layer of resilient material formed thereon, the patterned relief surface being provided in the resilient material layer. 
     
     
         8 . An apparatus according to  claim 1  wherein the relief surface is formed on an inner surface of the passage such that the filter material engages the relief surface of the passage and the relief pattern is impressed into the surface of the filter rod as the filter rod passes through the passage. 
     
     
         9 . An apparatus according to any preceding claim wherein the passage is configured to heat the filter tow material as is passes therethrough. 
     
     
         10 . An apparatus according to  claim 9  wherein the passage includes at least one inlet tube to allow steam to be introduced into the interior of the passage to heat the filter tow material. 
     
     
         11 . An apparatus according to  claim 9  or  claim 10  wherein the passage comprises a double wall structure along at least part of its length, comprising an outer wall and an inner wall spaced from the outer wall to define a cavity therebetween. 
     
     
         12 . An apparatus according to any of  claims 9 - 11  wherein the passage includes at least one heating element to heat the filter tow material within the passage, wherein the heating element(s) may comprise electrical heating element(s). 
     
     
         13 . An apparatus according to any preceding claim further comprising a pressing member configured to impart an inward pressing force on the belt and/or filter rod as the filter rod is formed in the passage. 
     
     
         14 . A method of manufacturing a filter rod for a cigarette or other smoking article using a filter rod manufacturing apparatus as defined in any preceding claim wherein the passage includes a first open end for introduction of filter material and a second open end for expulsion of a formed filter rod, the passage narrowing between the first end and the second end so that as filter material is conveyed through the passage, it is compressed to form a filter rod, the method comprising:
 feeding loose filter tow material onto the belt;   conveying the filter tow material on the belt through the passage from the first open end to the second open end and thereby compressing the filter tow material to form a filter rod; and   impressing a relief pattern on a surface of the filter rod as it passes through the passage.   
     
     
         15 . A method according to  claim 14  wherein the relief surface is formed on the belt, the method further comprising the relief pattern being impressed on the surface of the filter rod by the patterned relief surface of the belt. 
     
     
         16 . An apparatus according to  claim 15  wherein an inner surface of the passage includes a relief surface, the method further comprising the relief pattern being impressed on the surface of the filter rod by the patterned relief surface on the inner surface of the passage.