Cigarette wrapper with novel pattern

Abstract

A wrapper for a smoking article has a base web and a plurality of elements each having at least a pair of patch areas where diffusivity is in the range of 0 to about 0.2 cm/sec. Patches of adjacent elements are circumferentially offset from one another along the axis of a smoking article. The add-on material can be applied by gravure printing in a single pass in a chevron pattern such that an apex of the element is co-linear with substantially symmetrically spaced points on a trailing, outer edge of an adjacent element. Testing elements may be simultaneously printed with the add-on material to monitor diffusivity and/or presence of add-on material.

1 . (canceled) 
     
     
         2 . A smoking article comprising:
 a tobacco rod, the tobacco rod including,
 a wrapper including a plurality of patch elements arranged in circumferentially extending, longitudinally spaced-apart, mutually offset rows, the patch elements of such number, size, and diffusivity value that the smoking article exhibits an IP performance of less than about 15%; and exhibits an average SE performance less than about 35°. 
   
     
     
         3 . A method of achieving ignition propensity performance in a smoking article together with statistically fewer self-extinguishments in such smoking articles, comprising:
 establishing on a wrapper of the smoking article a plurality of patch elements arranged in circumferentially extending, longitudinally spaced-apart, mutually offset rows,   the establishing step including establishing the patch elements at desired size and diffusivity value such that the smoking article exhibits an IP performance of less than 15%, and exhibits an average SE performance less than 35%.   
     
     
         4 . The method of  claim 3 , wherein the diffusivity value is established in the range of 0 to 0.2 cm/sec. 
     
     
         5 . The method of  claim 3 , further comprising:
 forming the patches by single-pass printing of an aqueous solution containing starch, calcium carbonate, and an anti-wrinkling agent.   
     
     
         6 . The method of  claim 5 , wherein the establishing further comprises applying the rows of patch elements to a base web according to a chevron form. 
     
     
         7 . A process of making wrapper for a smoking article comprising:
 applying an add-on material on a base web in the form of a plurality of patch elements; and   controlling diffusivity values in the patch elements to lie in the range of 0 to 0.2 cm/sec using an aqueous solution of starch, calcium carbonate, and an anti-wrinkling agent.   
     
     
         8 . The process of  claim 7 , further comprising:
 selecting the anti-wrinkling agent, the anti-wrinkling agent including propylene glycol, 1,2 propylene glycol, glycerin, or any combination thereof.   
     
     
         9 . The process of  claim 7 , further comprising:
 slitting the base web to form bobbins.   
     
     
         10 . The process of  claim 7 , wherein the elements of patches are applied to the base web in a chevron pattern. 
     
     
         11 . The process of  claim 10 , wherein the patch elements are applied to the base web in a chevron pattern such that an apex of a lagging chevron is essentially transverse of an outer edge portion of a leading chevron. 
     
     
         12 . The process of  claim 10 , wherein the chevron pattern has an angle with respect to the transverse direction of the web, which angle lies in the range of 0.5° to 5°. 
     
     
         13 . A wrapper substantially free of creases and frayed edges, the wrapper in a condition of having been formed by:
 printing an add-on material on a base web in the form of a plurality of elements of patches; and   controlling diffusivity in the patches to lie in the range of 0 to 0.2 cm/sec using an aqueous solution of starch, calcium carbonate, and an anti-wrinkling agent, the aqueous solution in a condition of having been maintained at a temperature ranging from 120° F. to 140° F. prior to application.   
     
     
         14 . A method of conducting quality control in a manufacture of a wrapper comprising rows of occlusive elements, the method comprising:
 printing a first pattern of the rows of occlusive elements in a first lane along a base web with an add-on material and a gravure roller having a cell geometry; and   concurrently printing a second pattern of test elements in a second lane along the base web with the add-on material and the cell geometry;   conducting on portions of the second pattern testing for diffusivity; and   optionally testing for a presence of the first pattern;   whereby at least one of a diffusivity value and a presence of the first pattern is monitored.   
     
     
         15 . The method of  claim 14 , wherein each test element has sufficient size, geometry, or both size and geometry to facilitate measurement of diffusivity.