Smoking article with modified smoke delivery

Abstract

A smoking article ( 10 ) comprises a tobacco rod ( 12 ) wrapped with a paper wrapper ( 14 ), and a patch ( 16 ) of material between the tobacco rod and the paper wrapper that extends along the tobacco rod from or near the mouth end (B) to an intermediate point along the rod. The patch has a structure such that it provides a path for smoke from tobacco upstream of the patch to the mouth end that has less resistance to smoke flow than a path through the tobacco under the patch, thus delivering smoke from the upstream part of the tobacco rod to the smoker more efficiently. The patch may also increase the static burn rate of the latter part of the smoking article.

1 . A smoking article comprising:
 a tobacco rod;   a wrapper around the tobacco rod; and   a patch of material positioned between the tobacco rod and the wrapper and extending longitudinally along the tobacco rod from an intermediate point along the tobacco rod towards a mouth end of the tobacco rod, the material having structure such that the patch provides a path for smoke from tobacco upstream of the patch towards the mouth end that has less resistance to smoke flow than a path through the tobacco under the patch, and wherein the patch comprises at least one burn-enhancer to increase the static burn rate of the smoking article over the length comprising the patch.   
     
     
         2 . The smoking article according to  claim 1 , wherein the patch extends longitudinally from the intermediate point to the mouth end of the tobacco rod. 
     
     
         3 . The smoking article according to  claim 1 , wherein the patch extends longitudinally from the intermediate point to a second point between the intermediate point and the mouth end. 
     
     
         4 . The smoking article according to  claim 3 , wherein the second point is between 1% and 40% of the total length of the tobacco rod from the mouth end. 
     
     
         5 . The smoking article according to  claim 1 , wherein the patch extends longitudinally over substantially 10% to 90% of the total length of the tobacco rod. 
     
     
         6 . The smoking article according to  claim 5 , wherein the patch extends longitudinally over substantially 40% to 80% of the total length of the tobacco rod. 
     
     
         7 . The smoking article according to  claim 1 , wherein the patch extends substantially around the whole circumference of the tobacco rod. 
     
     
         8 . The smoking article according to  claim 1 , wherein the patch comprises one or more portions of material disposed around the circumference of the tobacco rod. 
     
     
         9 . The smoking article according to  claim 1 , wherein the patch comprises a foam material. 
     
     
         10 . The smoking article according to  claim 1 , wherein the patch comprises a corrugated material having corrugations that extend substantially longitudinally along the tobacco rod. 
     
     
         11 . The smoking article according to  claim 10 , wherein the corrugated material has a laminate structure comprising a corrugated layer and a non-corrugated layer. 
     
     
         12 . The smoking article according to  claim 11 , wherein the non-corrugated layer is positioned between the tobacco rod and the corrugated layer. 
     
     
         13 . The smoking article according to  claim 49 , wherein the non-corrugated layer is positioned between the corrugated layer and the paper wrapper. 
     
     
         14 . The smoking article according to  claim 10 , wherein the corrugated material has a laminate structure comprising a corrugated layer sandwiched between two noncorrugated layers. 
     
     
         5 . The smoking article according to  claim 1 , wherein the patch comprises an embossed material having indentations that extend substantially longitudinally along the tobacco rod. 
     
     
         16 . The smoking article according to  claim 1 , wherein the patch comprises a grooved material having grooves that extend substantially longitudinally along the tobacco rod. 
     
     
         17 . The smoking article according to  claim 1 , wherein the patch comprises a fibrous sheet material. 
     
     
         18 . The smoking article according to  claim 1 , wherein the patch has a color different from the wrapper and the tobacco rod. 
     
     
         19 . The smoking article according to  claim 1 , wherein the tobacco rod has a reduced weight of tobacco per unit length under the patch compared to upstream of the patch. 
     
     
         20 . The smoking article according to  claim 19 , wherein the reduced weight is created by trimming tobacco from the outside of the tobacco rod. 
     
     
         21 . The smoking article according to  claim 19 , wherein the reduced weight is created by trimming tobacco from a tobacco bead from which the tobacco rod is to be cut. 
     
     
         22 . The smoking article according to  claim 1 , wherein the smoking article further comprises a filter unit attached to the mouth end of the tobacco rod. 
     
     
         23 . The smoking article according to  claim 22 , wherein the filter unit is provided with one or more ventilation holes. 
     
     
         24 . A method of fabricating a smoking article comprising:
 providing a rod of tobacco;   disposing a patch of material over the rod of tobacco such that the patch extends longitudinally along the rod from an intermediate point along the rod towards a mouth end of the rod, the material having a structure and the patch being oriented such that, in the completed smoking article, the patch provides a path for smoke from tobacco upstream of the patch towards the mouth end that has less resistance to smoke flow than a path through the tobacco under the patch, wherein the patch comprises at least one burn-enhancer to increase the static burn rate of the smoking article over the length comprising the patch; and   wrapping a wrapper around the rod.   
     
     
         25 . The method according to  claim 24 , wherein disposing the patch of material comprises positioning the patch on the rod of tobacco before wrapping the wrapper around the rod. 
     
     
         26 . The method according to  claim 50 , wherein disposing the patch of material comprises adhering the patch to an inner surface of the paper wrapper before wrapping the wrapper around the rod. 
     
     
         27 . The method according to  claim 24 , wherein the patch extends longitudinally from the intermediate point to the mouth end of the rod of tobacco. 
     
     
         28 . The method according to  claim 24 , wherein the patch extends longitudinally from the intermediate point to a second point between the intermediate point and the mouth end. 
     
     
         29 . The method according to  claim 28 , wherein the second point is between 1% and 40% of the total length of the rod of tobacco from the mouth end. 
     
     
         30 . The method according to  claim 24 , wherein the patch extends longitudinally over substantially 10% to 90% of the total length of the rod. 
     
     
         31 . The method according to  claim 30 , wherein the patch extends longitudinally over substantially 40% to 80% of the total length of the rod. 
     
     
         32 . The method according to  claim 24 , wherein the patch extends substantially around the whole circumference of the rod of tobacco. 
     
     
         33 . The method according to  claim 24 , wherein the patch comprises one or more portions of material disposed around the circumference of the rod of tobacco. 
     
     
         34 . The method according to  claim 24 , wherein the patch comprises a foam material. 
     
     
         35 . The method according to  claim 50 , wherein the patch comprises a corrugated material having corrugations, the patch being disposed such that the corrugations extend substantially longitudinally along the rod of tobacco. 
     
     
         36 . The method according to  claim 35 , wherein the corrugated material has a laminate structure comprising a corrugated layer and a non-corrugated layer. 
     
     
         37 . The method according to  claim 36 , wherein the patch is disposed such that the non-corrugated layer is positioned between the tobacco rod and the corrugated layer. 
     
     
         38 . The method according to  claim 36 , wherein the patch is disposed such that the noncorrugated layer is positioned between the corrugated layer and the paper wrapper. 
     
     
         39 . The method according to  claim 35 , wherein the corrugated material has a laminate structure comprising a corrugated layer sandwiched between two noncorrugated layers. 
     
     
         40 . The method according to  claim 24 , wherein the patch comprises an embossed material, the patch disposed such that indentations in the material extend substantially longitudinally along the rod of tobacco. 
     
     
         41 . The method according to  claim 24 , wherein the patch comprises a grooved material, the patch disposed such that the grooves extend substantially longitudinally along the rod of tobacco. 
     
     
         42 . The method according to  claim 24 , wherein the patch comprises a fibrous sheet material. 
     
     
         43 . The method according to  claim 50 , wherein the patch has a color different from the paper wrapper and the rod of tobacco. 
     
     
         44 . The method according to  claim 24 , wherein the rod of tobacco has a reduced weight of tobacco per unit length under the patch compared to upstream of the patch. 
     
     
         45 . The method according to  claim 24 , further comprising:
 trimming tobacco from outside of the rod of tobacco over an area where the patch is to be disposed, thereby creating a reduced weight; and   disposing the patch over the rod of tobacco so that the patch covers the area from which tobacco has been trimmed.   
     
     
         46 . The method according to  claim 24 , further comprising:
 trimming tobacco from outside of a bead of tobacco over an area where the patch is to be disposed, thereby creating a reduced weight;   cutting a rod of tobacco from the bead; and   disposing the patch over the rod of tobacco so that the patch covers the area from which tobacco has been trimmed.   
     
     
         47 . The method according to  claim 24 , further comprising attaching a filter unit to the smoking article. 
     
     
         48 . The method according to  claim 47 , wherein the filter unit is provided with one or more ventilation holes. 
     
     
         49 . The smoking article according to  claim 11 , wherein the wrapper is a paper wrapper. 
     
     
         50 . The method according to  claim 24 , wherein the wrapper is a paper wrapper.