Process for producing smoking articles with reduced ignition proclivity characteristics and products made according to same
A process for reducing the permeability of a paper wrapper used in the construction of a smoking article is disclosed. The paper wrapper is treated with a film-forming composition that forms treated discrete areas on the wrapper. The treated discrete areas have a permeability within a predetermined range sufficient to reduce the ignition proclivity properties of a smoking article made with the wrapper. In accordance with the present invention, the film-forming composition is applied as multiple layers to the paper wrapper. After each application step, the wrapper is dried. Applying the film-forming composition to the paper wrapper in multiple layers minimizes distortion and other adverse affects that may occur to the wrapper.
1. A paper wrapper for a smoking article comprising:
a paper web having a permeability of from about 60 Coresta to about 110 Coresta; and
treated discrete areas on the paper web comprising a film-forming layer in an amount from 1% up to 12% by weight based upon the weight of the paper web within the treated area, the film-forming layer comprising a non-fibrous film-forming composition comprising an alginate, a starch, a cellulose derivative, or mixtures thereof, the treated discrete areas being separated by untreated areas, the treated discrete areas having a permeability of greater than 10 Coresta to less than about 25 Coresta and a BMI of less than about 5 cm −1 , the treated areas reducing ignition proclivity of a smoking article incorporating the paper wrapper, the treated areas being spaced from each other at a distance of from about 10 mm to about 30 mm.
2. A paper wrapper as defined in claim 1 , wherein the treated discrete areas comprise a plurality of discrete circumferential bands.
3. A paper wrapper as defined in claim 2 , wherein the wrapper includes up to three circumferential bands.
4. A paper wrapper as defined in claim 2 , wherein the treated areas reduce the ignition proclivity of a smoking article incorporating the paper wrapper sufficient for the smoking article to self-extinguish when lit and placed on filter paper.
5. A paper wrapper as defined in claim 2 , wherein the bands have a width of from about 5 mm to about 10 mm.
6. A paper wrapper as defined in claim 2 , wherein the bands have a width of greater than about 4 mm.
7. A paper wrapper as defined in claim 1 , wherein the treated discrete areas comprise multiple layers of the non-fibrous film-forming composition.
8. A paper wrapper as defined in claim 7 , wherein the treated discrete areas comprise at least three layers of the non-fibrous film-forming composition.
9. A paper wrapper as defined in claim 7 , wherein the treated discrete areas comprise at least a first layer of the non-fibrous film-forming composition and a second layer of the non-fibrous film-forming composition, and wherein the first layer contains a greater amount of the non-fibrous film-forming composition than the second layer.
10. A paper wrapper as defined in claim 9 , wherein the first layer contains the non-fibrous film-forming composition in an amount that is at least 1% by weight greater than the amount of the non-fibrous film-forming composition contained in the second layer.
11. A paper wrapper as defined in claim 1 , wherein the non-fibrous film-forming composition comprises a polyvinyl acetate.
12. A paper wrapper as defined in claim 1 , wherein the non-fibrous film-forming composition comprises a polyvinyl alcohol.
13. A paper wrapper as defined in claim 1 , wherein the non-fibrous film-forming composition comprises carboxymethyl cellulose.
14. A paper wrapper as defined in claim 1 , wherein the paper web has a permeability of from about 60 Coresta to about 90 Coresta.
15. A paper wrapper as defined in claim 1 , wherein the paper web has a basis weight of from about 18 gsm to about 60 gsm.
16. A paper wrapper as defined in claim 1 , further comprising a burn control additive applied to the paper web.
17. A paper wrapper as defined in claim 16 , wherein the burn control additive comprises an alkali metal salt.
18. A paper wrapper as defined in claim 17 , wherein the alkali metal sat comprises a citrate.
19. A paper wrapper as defined in claim 1 , wherein the non-fibrous film-forming composition contains a particulate inorganic filler.
20. A paper wrapper as defined in claim 19 , wherein the particulate inorganic filler comprises a non-reactive filler.
21. A paper wrapper as defined in claim 20 , wherein the particulate inorganic filler comprises a metal oxide or calcium carbonate.
22. A paper wrapper as defined in claim 1 , wherein the treated areas have a BMI of less than about 3 cm −1 .
23. A paper wrapper as defined in claim 1 , wherein the paper web comprises cellulosic fibers and a filler.
24. A paper wrapper as defined in claim 1 , wherein the non-fibrous film-forming composition comprises an alginate and a starch.
25. A paper wrapper as defined in claim 1 , wherein the non-fibrous film-forming composition comprises a starch and a cellulose derivative.
26. A paper wrapper for a smoking article comprising:
a paper web having a permeability of from about 60 Coresta to about 110 Coresta, the paper web containing a filler; and
treated discrete areas on the paper web comprising a non-fibrous film-forming polymer coating in an amount from 1% up to 12% by weight based upon the weight of the paper web within the treated area, the non-fibrous film-forming polymer coating comprising an alginate, a starch, a cellulose derivative, or mixtures thereof and optionally a filler, the treated discrete areas being separated by untreated areas, the treated discrete areas comprising a plurality of circumferential bands when the paper wrapper is wrapped around a smokeable filler, the circumferential bands having a width of at least 4 mm and being spaced from each other a distance of from about 10 mm to about 30 mm, the treated discrete areas having a permeability of greater than 10 Coresta to less than about 25 Coresta, the treated areas reducing ignition proclivity of a smoking article incorporating the paper wrapper.
27. A paper wrapper as defined in claim 26 , wherein the treated areas reduce the ignition proclivity of a smoking article incorporating the paper wrapper sufficient for the smoking article to self-extinguish when lit and placed on filter paper.
28. A paper wrapper as defined in claim 26 , wherein the paper wrapper includes up to three circumferential bands.
29. A paper wrapper as defined in claim 26 , wherein the bands have a width of from about 5 mm to about 10 mm.
30. A paper wrapper as defined in claim 26 , wherein the polymer coatings consist essentially of the alginate.
31. A paper wrapper as defined in claim 26 , wherein the polymer coatings consist essentially of the starch.
32. A paper wrapper as defined in claim 31 , wherein the polymer coatings contain the filler.
33. A paper wrapper as defined in claim 32 , wherein the filler comprises metal oxide particles or calcium carbonate particles.
34. A paper wrapper as defined in claim 26 , wherein the polymer coatings consist essentially of a mixture of starch and alginate.
35. A paper wrapper as defined in claim 34 , wherein the polymer coatings contain the filler.
36. A paper wrapper as defined in claim 35 , wherein the filler comprises metal oxide particles or calcium carbonate particles.
37. A paper wrapper as defined in claim 26 , wherein the polymer coatings consist essentially of a mixture of starch and carboxymethyl cellulose.
38. A paper wrapper as defined in claim 37 , wherein the polymer coatings contain the filler.
39. A paper wrapper as defined in claim 38 , wherein the filler comprises metal oxide particles or calcium carbonate particles.
40. A paper wrapper as defined in claim 26 , wherein the polymer coatings contain the filler.
41. A paper wrapper as defined in claim 40 , wherein the filler comprises metal oxide particles or calcium carbonate particles.
42. A paper wrapper as defined in claim 26 , wherein the paper web has a permeability of from about 60 Coresta to about 90 Coresta.
43. A paper wrapper as defined in claim 26 , wherein the bands have a BMI of less than about 3 cm −1 .
44. A paper wrapper for a smoking article comprising:
a paper web having a permeability of greater than about 55 Coresta, the paper web comprising cellulosic fibers and a filler, the filler being present in the paper web in an amount from about 10% to about 40% by weight, the paper web having a basis weight of from about 15 gsm to about 40 gsm; and
treated discrete areas on the paper web comprising a non-fibrous film-forming polymer coating in an amount from 1% up to 12% by weight based upon the weight of the paper web within the treated area, the film-forming polymer coating comprising a starch and optionally a filler, the treated discrete areas comprising a plurality of discrete circumferential bands, the bands having a width greater than about 4 mm, the treated discrete areas having a permeability of greater than 10 Coresta to less than about 20 Coresta.
45. A paper wrapper as defined in claim 44 , further comprising a burn control additive applied to the paper web.
46. A paper wrapper as defined in claim 45 , wherein the burn control additive comprises an alkali metal salt.
47. A paper wrapper as defined in claim 46 , wherein the alkali metal salt comprises a citrate.
48. A paper wrapper as defined in claim 44 , wherein the discrete circumferential bands have a width of from about 5 mm to about 10 mm.
49. A paper wrapper as defined in claim 44 , wherein the polymer coatings consist essentially of starch.
50. A paper wrapper as defined in claim 44 , wherein the polymer coatings consist essentially of starch and a filer.
51. A paper wrapper as defined in claim 50 , wherein the filler comprises a metal oxide.
52. A paper wrapper as defined in claim 50 , wherein the filler comprises calcium carbonate.
53. A paper wrapper as defined in claim 44 , wherein the treated areas are sufficient to reduce ignition proclivity by reducing oxygen to a smoldering coal of a smoking article incorporating the paper wrapper as a coal burns and advances into the treated areas.
54. A smoking article comprising:
a column comprising tobacco; and
the paper wrapper as defined in claim 44 surrounding the column.
55. A smoking article comprising:
a column comprising tobacco; and
the paper wrapper as defined in claim 1 surrounding the column.
56. A smoking article comprising:
a column comprising tobacco; and
the paper wrapper as defined in claim 26 surrounding the column.