Smoking article wrapper having a window

Abstract

A wrapper (310) for a smoking article comprises a sheet material extending in a first direction (24) in which the wrapper (310) is wrapped around a smoking article and a second direction (20) perpendicular to the first direction (24). The wrapper (310) further comprises a window (312) in the sheet material, the window (312) having a perimeter. Any linear segment of the perimeter forming an angle of less than 10? with respect to the second direction (20) has a length of less than 0.5 millimeters, and any curved portion of the perimeter having a continuum of tangents each forming an angle of less than 10? with respect to the second direction (20) has a length of less than 0.5 millimeters. Such linear segments and curved portions of the perimeter are spaced apart by a distance of at least 0.5 millimeters along the length of the perimeter. The perimeter includes at least one linear segment forming an angle of less than 10 degrees with respect to the second direction (20) and having a length of less than 0.5 millimeters. The window (312) has a width of at least about 2 millimeters.

Claims

1. A smoking article comprising: an aerosol generating substrate; a mouthpiece; and a wrapper wrapped around at least a portion of the mouthpiece and at least a portion of the aerosol generating substrate to secure the mouthpiece to the aerosol generating substrate, wherein the wrapper comprises: a sheet material extending in a first direction in which the wrapper is wrapped around the mouthpiece and the aerosol generating substrate, and a second direction perpendicular to the first direction; and a window in the sheet material, the window having a perimeter; wherein any linear segment of the perimeter forming an angle of less than 10? with respect to the second direction has a length of less than 0.5 millimeters; wherein any curved portion of the perimeter having a continuum of tangents each forming an angle of less than 10? with respect to the second direction has a length of less than 0.5 millimeters; wherein such linear segments and curved portions of the perimeter are spaced apart by a distance of at least 0.5 millimeters along the length of the perimeter; wherein the perimeter includes at least one linear segment forming an angle of less than 10 degrees with respect to the second direction and having a length of less than 0.5 millimeters; and wherein the window has a width of at least about 2 millimeters.

2. A smoking article according to claim 1, wherein a continuous portion of the wrapper surrounding the perimeter of the window is free from adhesive, wherein the width of the continuous portion is at least about 0.5 millimeters.

3. A smoking article according to claim 1, wherein the perimeter includes at least one curved portion having a continuum of tangents each forming an angle of less than 10? with respect to the second direction and having a length of less than 0.5 millimeters.

4. A smoking article according to claim 1, wherein any linear segment of the perimeter that has a length of greater than 0.5 millimeters forms angles of greater than 10? with respect to the second direction.

5. A smoking article according to claim 1, wherein the perimeter comprises a first portion that defines a projection of the sheet material into the window, wherein the projection is delimited by the first portion of the perimeter and a straight line forming a tangent to each end of the first portion of the perimeter, and wherein the distance between the straight line and the point on the first portion of the perimeter furthest from the straight line in a direction perpendicular to the straight line is less than 1 millimeter.

6. A smoking article according to claim 5, wherein the first portion of the perimeter comprises at least one straight line segment having a length of at least 0.5 millimeters and wherein the first portion of the perimeter defines one or more internal angles of the window, each of the one or more internal angles being less than 220?.

7. A smoking article according to claim 5, wherein any projection of the sheet material into the window is delimited by a portion of the perimeter and a straight line forming a tangent to each end of the portion of the perimeter, and wherein the distance between the straight line and the point on the portion of the perimeter furthest from the straight line in a direction perpendicular to the straight line is less than 1 millimeter.

8. A smoking article according to claim 1, wherein the aerosol generating substrate is a tobacco rod, wherein the mouthpiece comprises one or more segments of filtration material, and wherein the wrapper is a tipping wrapper.

9. A wrapper for a smoking article, the wrapper comprising: a sheet material extending in a first direction in which the wrapper is wrapped around a smoking article and a second direction perpendicular to the first direction; and a window in the sheet material, the window having a perimeter; wherein any linear segment of the perimeter forming an angle of less than 10? with respect to the second direction has a length of less than 0.5 millimeters; wherein any curved portion of the perimeter having a continuum of tangents each forming an angle of less than 10? with respect to the second direction has a length of less than 0.5 millimeters; wherein such linear segments and curved portions of the perimeter are spaced apart by a distance of at least 0.5 millimeters along the length of the perimeter; wherein the perimeter includes at least one linear segment forming an angle of less than 10 degrees with respect to the second direction and having a length of less than 0.5 millimeters; and wherein the window has a width of at least about 2 millimeters.

10. A wrapper according to claim 9, wherein the perimeter includes at least one curved portion having a continuum of tangents each forming an angle of less than 10? with respect to the second direction and having a length of less than 0.5 millimeters.

11. A wrapper according to claim 9, wherein the perimeter comprises a first portion that defines a projection of the sheet material into the window, wherein the projection is delimited by the first portion of the perimeter and a straight line forming a tangent to each end of the first portion of the perimeter, and wherein the distance between the straight line and the point on the first portion of the perimeter furthest from the straight line in a direction perpendicular to the straight line is less than 1 millimeter.

12. A wrapper according to claim 11, wherein the first portion of the perimeter comprises at least one straight line segment having a length of at least 0.5 millimeters and wherein the first portion of the perimeter defines one or more internal angles of the window, each of the one or more internal angles being less than 220?.

13. A wrapper according to claim 11, wherein any projection of the sheet material into the window is delimited by a portion of the perimeter and a straight line forming a tangent to each end of the portion of the perimeter, and wherein the distance between the straight line and the point on the portion of the perimeter furthest from the straight line in a direction perpendicular to the straight line is less than 1 millimeter.

14. A wrapper according to claim 10, wherein the perimeter comprises a first portion that defines a projection of the sheet material into the window, wherein the projection is delimited by the first portion of the perimeter and a straight line forming a tangent to each end of the first portion of the perimeter, and wherein the distance between the straight line and the point on the first portion of the perimeter furthest from the straight line in a direction perpendicular to the straight line is less than 1 millimeter.

15. A wrapper according to claim 14, wherein the first portion of the perimeter comprises at least one straight line segment having a length of at least 0.5 millimeters and wherein the first portion of the perimeter defines one or more internal angles of the window, each of the one or more internal angles being less than 220?.

16. A smoking article according to claim 2, wherein the perimeter includes at least one curved portion having a continuum of tangents each forming an angle of less than 10? with respect to the second direction and having a length of less than 0.5 millimeters.

17. A smoking article according to claim 2, wherein any linear segment of the perimeter that has a length of greater than 0.5 millimeters forms angles of greater than 10? with respect to the second direction.

18. A smoking article according to claim 2, wherein the perimeter comprises a first portion that defines a projection of the sheet material into the window, wherein the projection is delimited by the first portion of the perimeter and a straight line forming a tangent to each end of the first portion of the perimeter, and wherein the distance between the straight line and the point on the first portion of the perimeter furthest from the straight line in a direction perpendicular to the straight line is less than 1 millimeter.

19. A smoking article according to claim 18, wherein the first portion of the perimeter comprises at least one straight line segment having a length of at least 0.5 millimeters and wherein the first portion of the perimeter defines one or more internal angles of the window, each of the one or more internal angles being less than 220?.

20. A smoking article according to claim 18, wherein any projection of the sheet material into the window is delimited by a portion of the perimeter and a straight line forming a tangent to each end of the portion of the perimeter, and wherein the distance between the straight line and the point on the portion of the perimeter furthest from the straight line in a direction perpendicular to the straight line is less than 1 millimeter.

Description

(1) The invention will now be further described, by way of example only, with reference to the accompanying drawings in which:

(2) FIG. 5 shows a wrapper in accordance with a first embodiment of the present invention; and

(3) FIG. 6 shows a wrapper in accordance with a second embodiment of the present invention.

(4) FIG. 5 shows a wrapper 410 having a rhombus-shaped window 412 formed from linear line segments 416 each having a length of greater than 0.5 millimeters. The angle 414 formed between each linear line segment 416 and the second direction 20 is greater than 10? so that lifting of the wrapper once wrapped in the first direction 24 around a smoking article is reduced or eliminated.

(5) FIG. 6 shows a wrapper 510 having an alternative window 512 formed from a series of curved line segments. The only curved portions 514 of the perimeter that have a continuum of tangents that each form an angle of less than 10? with respect to the second direction 20 are both shorter than 0.5 millimeters.

(6) The wrapper 510 further includes a projection 516 that extends into the window 512 and is delimited by a first portion 518 of the perimeter and a straight line 520 that forms a tangent to the two end points 522, 524 of the first portion 518. The distance 526 between the straight line 520 and the point on the first portion 518 of the perimeter furthest from the straight line 520 in a direction perpendicular to the straight line is less than 1 millimeter.