Low ignition propensity cigarette paper and manufacture thereof

Patent metadata

Field	Value
Publication number	US-10212967-B2
Application number	US-201514982167-A
Country	US
Kind code	B2
Filing date	Dec 29, 2015
Priority date	Dec 29, 2014
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

A wrapper of a smoking article includes a base web and at least one transverse banded region. The banded region includes a first zone, a second zone and a third zone of add-on material. The second zone has about 25% to about 75% less add-on material than the first zone and the third zone. The banded region is about 5 mm to about 9 mm wide and the second zone is centrally located between the first zone and the third zone. The second zone includes a plurality of dots of the add-on material spaced from adjacent dots in the second zone by a distance greater than a distance between adjacent dots in the first zone and the third zone.

First claim

I claim:

1. A low ignition propensity wrapper of a smoking article, comprising:
a base web; and
at least one transverse banded region comprising a first zone including dots of add-on material, a second zone including dots of the add-on material, and a third zone including the add-on material, the second zone having about 25% to about 75% less add-on material than the first zone, the dots in the second zone spaced from adjacent dots in the second zone by a distance greater than a distance between adjacent dots in the first zone, wherein the second zone is located between the first zone and the third zone, and
the add-on material includes starch.

2. The wrapper of claim 1 , wherein the first zone has a greater basis weight in grams per square meter than the second zone.

3. The wrapper of claim 2 , wherein the basis weight in grams per square meter of the first zone is at least twice the basis weight in grams per square meter of the second zone.

4. The wrapper of claim 1 , wherein the third zone includes dots of the add-on material.

5. The wrapper of claim 4 , wherein the first zone and the third zone have the same width.

6. The wrapper of claim 1 , wherein the banded region is about 5 mm to about 9 mm wide.

7. The wrapper of claim 1 , wherein the second zone has a higher diffusivity than the first zone.

8. The wrapper of claim 1 , wherein the second zone has a greater permeability than the first zone.

9. The wrapper of claim 1 , wherein the second zone is about 0.5 mm to about 1.5 mm wide.

10. The wrapper of claim 9 , wherein the second zone is about 1.0 mm wide.

11. The wrapper of claim 1 , wherein the dots of the add-on material in the first zone and the second zone have about a same thickness, the dots in the first and second zones formed by a gravure cylinder having hexagonal cells with cell walls 12 to 20 microns thick in the first zone and 20 to 80 microns thick in the second zone, the hexagonal cells in the second zone having a volume about 25% to about 75% less than the volume of the hexagonal cells in the first zone.

12. A method of making a low ignition propensity banded wrapper of a smoking article, comprising:
supplying a base web; and
forming at least one transverse banded region of an add-on material that includes starch on the base web, the banded region having a first zone including a plurality of dots of the add-on material, a second zone including a plurality of dots of the add-on material, and a third zone including a plurality of dots of the add-on material;
wherein the first and third zones are on opposite sides of the second zone,
wherein the second zone has a greater permeability than the first and third zones,
wherein the plurality of dots of the add-on material of the second zone have smaller dimensions than the dots of add-on material in each of the first and third zones, and the plurality of dots of the second zone are spaced from adjacent dots in the second zone by a distance greater than a distance between adjacent dots in the first zone.

13. The method of claim 12 , further comprising forming the first, second, and third zones by printing a single printed layer of add-on material on the base web, the dots in the first, second and third zones formed by a gravure cylinder having hexagonal cells with cell walls 12 to 20 microns thick in the first and third zones and 20 to 80 microns thick in the second zone, the hexagonal cells in the second zone having a volume about 25% to about 75% less than the volume of the hexagonal cells in the first and third zones.

14. The method of claim 12 , wherein the first and third zones have a greater basis weight in grams per square meter than the second zone.

15. The method of claim 14 , wherein the basis weight in grams per square meter of the first and third zones is at least twice the basis weight in grams per square meter of the second zone.

16. The method of claim 12 , wherein the printing comprises printing with a gravure cylinder having a plurality of cells etched thereon.

17. The method of claim 16 , wherein cells in a central portion of the gravure cylinder have smaller dimensions than cells on outer edges of the gravure cylinder.

18. The method of claim 17 , further including:
heating the add-on material;
applying the heated add-on material to the gravure cylinder; and
contacting the base web with the gravure cylinder.

19. The method of claim 18 , wherein the heating step comprises heating the add-on material to a temperature ranging from about 100° F. to about 140° F.

20. A low ignition propensity wrapper of a smoking article, comprising:
a base web; and
at least one transverse banded region comprising a first zone of add-on material, a second zone of the add-on material, and a third zone of the add-on material, the add-on material including starch and the second zone having about 25% to about 75% less add-on material than the first zone, about 25% to about 75% less add-on material than the third zone, or about 25% to about 75% less add-on material than the first zone and about 25% to about 75% less add-on material than the third zone, the banded region being about 5 mm to about 9 mm wide, the second zone being centrally located between the first zone and the third zone, the first and second zones each comprising a plurality of dots of the add-on material wherein the plurality of dots of the second zone are spaced from adjacent dots in the second zone by a distance greater than a distance between adjacent dots in the first zone.

21. The wrapper of claim 1 , wherein the banded region has a permeability of about 0 to about 12 CORESTA.

22. The wrapper of claim 1 , wherein the base web has a permeability of greater than about 60 CORESTA in regions outside of the at least one transverse banded region.

23. The method of claim 12 , wherein the add-on material has a same thickness in the first, second, and third zones.

24. The wrapper of claim 20 , wherein the add-on material is uniform across each of the first and third zones, the dots in the first and second zones formed by a gravure cylinder having hexagonal cells with cell walls 12 to 20 microns thick in the first zone and 20 to 80 microns thick in the second zone, the hexagonal cells in the second zone having a volume about 25% to about 75% less than the volume of the hexagonal cells in the first zone.

Assignees

• Altria Client Services Llc

Inventors

• Lee Michael H

Classifications

• A24C5/005

  Treatment of cigarette paper · CPC title

• A24D1/025 Primary

  the covers having material applied to defined areas, e.g. bands for reducing the ignition propensity · CPC title