METHOD OF FORMING SMOKING ARTICLES WITH MOUTH END CAVITIES

Abstract

A method of producing smoking articles, the method comprising a first step of providing a continuous array of first filter members (42), second filter segments (20) and tubular members (40). A tubular member (40) is provided between each pair of consecutive first filter members (42) and a second filter segment (20) is provided between each first filter member (42) and each tubular member (40). Each second filter segment (20) contains one or more breakable capsules, wherein each breakable capsule comprises an outer shell and an inner core containing an additive. The continuous array of first filter members (42), second filter segments (20) and tubular members (40) is then wrapped with a continuous sheet of plug wrap (44) to form a wrapped filter array, wherein the plug wrap (44) has a basis weight of less than 90 grams per square metre. The wrapped filter array is cut at an intermediate position along each first filter member (42) to provide multiple filter rods, each filter rod comprising two first filter segments (18), a tubular member (40) positioned between the first filter segments (18) and a second filter segment (20) provided between each first filter segment (18) and the tubular member (40). Next, a tobacco rod (12) is provided in axial alignment with and adjacent to each first filter segment (18) of one of the filter rods, and the filter rod and a portion of each tobacco rod (12) are wrapped in a tipping wrapper (50). Finally, the tipping wrapper (50) and the filter rod are cut at an intermediate position along the length of the tubular member (40) to form multiple smoking articles (10), each smoking article (10) comprising a tobacco rod (12) connected to a filter (14), wherein each filter (14) comprises a first filter segment (18) downstream of the tobacco rod (12), a second filter segment (20) downstream of the first filter segment (18), and a hollow tube segment (22) positioned between the second filter segment (20) and the mouth end of the filter (14). The hollow tube segment (22) defines a cavity (24) at the mouth end of the filter (14).

Claims

1. A method of producing smoking articles, the method comprising the steps of: providing a continuous array of first filter members, second filter segments and tubular members, wherein a tubular member is provided between each pair of consecutive first filter members and wherein a second filter segment is provided between each first filter member and each tubular member; wrapping the continuous array of first filter members, second filter segments and tubular members with a continuous sheet of plug wrap to form a wrapped filter array; cutting the wrapped filter array at an intermediate position along each first filter member to provide multiple filter rods, each filter rod comprising two first filter segments, a tubular member positioned between the first filter segments and a second filter segment provided between each first filter segment and the tubular member; providing a tobacco rod in axial alignment with and adjacent to each first filter segment of a filter rod; wrapping the filter rod and a portion of each tobacco rod in a tipping wrapper; and cutting the tipping wrapper and the filter rod at an intermediate position along the length of the tubular member to form multiple smoking articles, each smoking article comprising a tobacco rod connected to a filter, wherein each filter comprises a first filter segment downstream of the tobacco rod, a second filter segment downstream of the first filter segment, and a hollow tube segment positioned between the second filter segment and the mouth end of the filter, the hollow tube segment defining a cavity at the mouth end of the filter, wherein the difference between the ovality of the tube segment after 50% deformation of the filter and the ovality of the tube segment prior to deformation of the filter is less than 25%.

2. The method according to claim 1, wherein each second filter segment contains one or more breakable capsules, each breakable capsule comprising an outer shell and an inner core containing an additive.

3. The method according to claim 1, wherein the plug wrap has a basis weight of less than 90 grams per square meter.

4. The method according to claim 1, wherein the first filter segment is used for adjusting the resistance to draw (RTD).

5. The method according to claim 1, wherein the tubular member is formed by wrapping a plurality of substantially continuous paper strips in a parallel manner or in a spiral manner about a cylindrical mandrel so as to form a substantially continuous tube on the mandrel.

6. The method according to claim 1, further comprising providing a segment plug wrap circumscribing each second filter segment, wherein each segment plug wrap is substantially impermeable to the additive in the inner core of the one or more breakable capsules.

7. The method according to claim 1, wherein the wall of each tubular member has a thickness of between 150 micrometers and 500 micrometers.

8. The method according to claim 1 wherein each tubular member has a length of at least 4 mm.

9. The method according to claim 1, wherein each tubular member comprises a coating layer on an inner surface thereof.

10. The method according to claim 1, wherein each tubular member is formed of a plurality of overlapping paper layers.

11. The method according to claim 10, wherein adjacent paper layers of each tubular member are adhered together by an intermediate layer of an adhesive.

12. The method according to claim 10, wherein each tubular member comprises at least two paper layers.

13. The method of claim 1, wherein the filter has an un-smoked compressive strength of at least about 20 Newtons at 50% compression.

14. The method of claim 1, wherein the ovality of the hollow tube segment after a 50% deformation of the filter is less than 25%.

15. The method of claim 1, wherein the compressive strength of the hollow tube segment is at least 20 Newtons at 50% compression.

16. A smoking article comprising a tobacco rod connected to a filter, wherein each filter comprises a first filter segment downstream of the tobacco rod, a second filter segment downstream of the first filter segment, and a hollow tube segment positioned between the second filter segment and a mouth end of the filter, the hollow tube segment defining a cavity at the mouth end of the filter, wherein the difference between the ovality of the tube segment after 50% deformation of the filter and the ovality of the tube segment prior to deformation of the filter is less than 25%.

17. The smoking article according to claim 16, wherein each second filter segment contains one or more breakable capsules, each breakable capsule comprising an outer shell and an inner core containing an additive.

18. The smoking article according to claim 16, wherein the plug wrap has a basis weight of less than 90 grams per square meter.

19. A smoking article produced by a method comprising the steps of: providing a continuous array of first filter members, second filter segments and tubular members, wherein a tubular member is provided between each pair of consecutive first filter members and wherein a second filter segment is provided between each first filter member and each tubular member; wrapping the continuous array of first filter members, second filter segments and tubular members with a continuous sheet of plug wrap to form a wrapped filter array; cutting the wrapped filter array at an intermediate position along each first filter member to provide multiple filter rods, each filter rod comprising two first filter segments, a tubular member positioned between the first filter segments and a second filter segment provided between each first filter segment and the tubular member; providing a tobacco rod in axial alignment with and adjacent to each first filter segment of a filter rod; wrapping the filter rod and a portion of each tobacco rod in a tipping wrapper; and cutting the tipping wrapper and the filter rod at an intermediate position along the length of the tubular member to form multiple smoking articles, each smoking article comprising a tobacco rod connected to a filter, wherein each filter comprises a first filter segment downstream of the tobacco rod, a second filter segment downstream of the first filter segment, and a hollow tube segment positioned between the second filter segment and the mouth end of the filter, the hollow tube segment defining a cavity at the mouth end of the filter, wherein the difference between the ovality of the tube segment after 50% deformation of the filter and the ovality of the tube segment prior to deformation of the filter is less than 25%.

20. The smoking article according to claim 19, wherein each second filter segment contains one or more breakable capsules, each breakable capsule comprising an outer shell and an inner core containing an additive.

Description

[0039] The invention will now be further described, by way of example only, with reference to the accompanying drawings in which:

[0040] FIG. 1 shows a method of forming a plurality of smoking article filter rods, in accordance with the present invention;

[0041] FIG. 2 shows a dual filter rod;

[0042] FIG. 3 shows a quadruple filter rod;

[0043] FIG. 4 shows an exemplary method of forming a smoking article using a dual filter rod, in accordance with the present invention;

[0044] FIG. 5 shows a smoking article made in accordance with the method shown in FIG. 4;

[0045] FIG. 6 shows the mouth end of the smoking article of FIG. 5 with the filter unwrapped; and

[0046] FIG. 7 shows an exemplary method of forming a tubular member.

[0047] FIG. 1 illustrates a process for forming a plurality of smoking article filter rods in accordance with the invention. A substantially continuous array of filter components is formed by providing a plurality of tubular members 40, a plurality of flavour containing filter segments 20 and a plurality of rod end filter members 42. A tubular member 40 is provided between each pair of consecutive rod end filter members 42, and a flavour containing filter segment 20 is provided between each rod end filter member 42 and each tubular member 40. The substantially continuous array of filter components is then wrapped in a continuous sheet of plug wrap 44 to form a wrapped filter array.

[0048] To form a plurality of filter rods, a plurality of first cuts 46 is made through at least some of the rod end filter members 42 of the wrapped filter array, each first cut 46 positioned at an intermediate position along the length of the respective rod end filter member 42. The resilience of each tubular member 40 advantageously prevents collapse of the cavities defined therein during the cutting process and subsequent handling of the filter rods and any smoking articles incorporating filters manufactured from the filter rods.

[0049] To form a dual filter rod, as shown in FIG. 2, the wrapped filter array is cut through each rod end filter member 42 so as to provide a filter rod having a rod end filter segment 18 at each end, two flavor containing filter segments 20 positioned between the two rod end filter segments 18, and a tubular member 40 positioned between the two flavor containing filter segments 20. The dual filter rod essentially defines two smoking article filters 14 which are joined by a continuous plug wrap 44 and a tubular member 40.

[0050] Alternatively, a quadruple filter rod, as shown in FIG. 3, can be formed by cutting the wrapped filter array through every other filter member 42 so as to provide a filter rod which essentially comprises two joined dual filter rods.

[0051] The formed filter rods are used to form two or more smoking articles. For example, as shown in FIG. 4, a dual filter rod can be used to form two filter cigarettes 10 by placing a tobacco rod 12 in axial alignment with each end of the filter rod. A tipping wrapper 50 is then wrapped around the filter rod and a portion of each tobacco rod 12 adjacent the filter rod. The tipping wrapper 50, the plug wrap 44 and the tubular member 40 are then cut along a cut line 52 to form two filter cigarettes. The resilience of the tubular member 40 prevents collapse or deformation of the mouth end cavities of each cigarette 10 during the cutting process.

[0052] As shown in FIGS. 5 and 6, each filter cigarette 10 comprises a wrapped rod 12 of tobacco cut filler which is attached at one end to an axially aligned filter 14. A tipping wrapper 16 formed from tipping wrapper 50 circumscribes the filter 14 and a portion of the wrapped rod 12 of tobacco to join together the two portions of the cigarette 10.

[0053] As shown in FIG. 6, the filter 14 comprises the rod end filter segment 18, the flavour containing filter segment 20, and a mouth end hollow tube segment 22 formed from part of a tubular member 40. The segments 18, 20 and 22 are circumscribed by a combining plug wrap 23 formed from the continuous sheet of plug wrap 44, the combining plug wrap 23 connecting the three segments to form the filter 14.

[0054] The rod end filter segment 18 and the flavour containing filter segment 20 are formed of a suitable filtration material, such as cellulose acetate tow. Furthermore, the flavour containing filter segment 20 comprises a suitable flavourant, which may be provided in the form of one or more breakable capsules contained within the flavour containing filter segment 20. In this case, the one or more breakable capsules are ruptured by the consumer when desired by squeezing the flavour containing filter segment 20 between the consumer's fingers.

[0055] The mouth end hollow tube segment 22 defines a mouth end cavity 24 in the filter 14 which extends between the downstream end of the flavour containing filter segment 20 and the mouth end edge of the filter 14. The mouth end hollow tube segment 22 provides sufficient mechanical strength and resilience to resist deformation of the mouth end cavity 24, for example during the rupture of the one or more breakable capsules when present in the flavour containing filter segment 20.

[0056] FIG. 7 shows an exemplary method of forming a continuous tube 30 which can be cut to form a plurality of tubular members 40. To form the continuous tube 30, a plurality of continuous paper plies 32 are spirally wound around a cylindrical mandrel 34 in a staggered, overlapping arrangement. A suitable adhesive may be applied to one or more of the plies 32 using an adhesive bath 36 prior to winding each ply around the mandrel 34. The plies 32 are driven by a rubber belt 38 so that the continuous tube 30 rotates around the mandrel 34 until it is cut into desired lengths further downstream.