METHOD FOR MAKING A FILTER ELEMENT OR MOUTHPIECE

Abstract

There is disclosed a method of making a filter element or mouthpiece (300) comprising the steps of: advancing filtering material in the longitudinal direction; drawing the advancing filtering material into a shaping element (110), to thereby form a longitudinally extending rod of filtering material comprising a channel extending longitudinally through the rod of filtering material; wherein the shaping element (110) comprises a chamber and a shaping rod (200) which extends longitudinally within the chamber, the inner surface of the chamber shaping the advancing filtering material to form the longitudinally extending rod of filtering material, and the shaping rod (200) shaping the advancing filtering material to form the channel extending longitudinally through the rod of filtering material; and wherein the shaping element (110) applies an additive to the filtering material.

Claims

1. A method of making a filter element or mouthpiece comprising the steps of: advancing filtering material in a longitudinal direction; and drawing the advancing filtering material into a shaping element, to thereby form a longitudinally extending rod of filtering material comprising a channel extending longitudinally through the rod of filtering material; wherein the shaping element comprises a chamber and a shaping rod which extends longitudinally within the chamber, an inner surface of the chamber shaping the advancing filtering material to form the longitudinally extending rod of filtering material, and the shaping rod shaping the advancing filtering material to form the channel extending longitudinally through the rod of filtering material; and wherein the shaping element applies an additive to the advancing filtering material.

2. The method according to claim 1, wherein the shaping rod applies the additive to the advancing filtering material.

3. The method according to claim 1, wherein the shaping rod comprises a cavity and a plurality of holes which are coupled to the cavity, wherein the additive travels from the cavity and exits the shaping rod through the plurality of holes as the advancing filtering material passes through the shaping element.

4. The method according to claim 1, wherein the shaping rod comprises an outer surface which defines a shape of the channel extending longitudinally through the rod of filtering material.

5. The method according to claim 3, wherein the additive is a liquid.

6. The method according to claim 5, wherein the additive forms a spray as the additive exits the plurality of holes.

7. The method according to claim 1, wherein a plasticiser is applied to the advancing filtering material.

8. The method according to claim 7, wherein the plasticiser is applied to the advancing filtering material before the advancing filtering material is drawn into the shaping element.

9. The method according to claim 1, wherein steam is applied to the advancing filtering material as the advancing filtering material passes through the shaping element.

10. The method according to claim 9, wherein the steam is applied directly to the advancing filtering material within the shaping element.

11. The method according to claim 9, wherein the steam is applied directly to an outer surface of the longitudinally extending rod of filtering material as the longitudinally extending rod of filtering material forms within the shaping element.

12. The method according to claim 1, further comprising cutting the longitudinally extending rod of filtering material to form the filter element or mouthpiece.

13. The method according to claim 1, wherein the additive is a smoke or aerosol modifying agent.

14. The method according to claim 13, wherein the additive is a flavouring agent.

15. The method according to claim 14, wherein the flavouring agent is one or more of menthol, spearmint, clove, nutmeg and cinnamon.

16. A filter element or mouthpiece formed by the method according to claim 1.

17. A shaping rod for use in a method of making a filter element or mouthpiece comprising: a longitudinal rod comprising a cavity and an outer surface; a plurality of holes located in the outer surface of the longitudinal rod, wherein the plurality of holes are coupled to the cavity.

18. The shaping rod according to claim 17, wherein the plurality of holes extend from the outer surface to the cavity.

19. An apparatus for making a filter element or mouthpiece, the apparatus comprising: a shaping element comprising a chamber and the shaping rod according to claim 17, wherein the shaping rod extends longitudinally within the chamber.

20. The apparatus according to claim 19, wherein the chamber comprises one or more steam inlets.

21. The apparatus according to claim 20, wherein the one or more steam inlets are configured to apply steam to filtering material within the chamber.

22. The apparatus according to claim 19, wherein, in use, the shaping rod is configured to apply a flavouring agent to filtering material within the chamber.

23. A filter element or mouthpiece comprising: a longitudinally extending core of filtering material, wherein the longitudinally extending core of filtering material has an outer surface and an inner surface; a channel extending from an end of the core, wherein the channel is defined by the inner surface of the core; a layer of additive disposed on the inner surface of the core.

24. The filter element or mouthpiece according to claim 23, wherein the additive is a smoke or aerosol modifying agent.

25. The filter element or mouthpiece according to claim 24, wherein the additive is a flavouring agent.

26. A filter comprising the filter element according to claim 16.

27. A multiple rod comprising a plurality of mouthpieces or filter elements according to claim 16 joined end-to-end in a mirror image relationship.

28. A smoking article comprising a mouthpiece or filter element according to claim 16, the mouthpiece or filter element being joined to a rod of smokable material.

Description

[0077] Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0078] FIG. 1 is a schematic view of the method according to the present invention;

[0079] FIG. 2 is a perspective view of a shaping element according to the present invention;

[0080] FIG. 3 is perspective view of a filter element or mouthpiece according to the present invention.

[0081] FIG. 1 shows a schematic view of a method for making a filter element or mouthpiece according to the present invention.

[0082] Filamentary tow 100 is drawn simultaneously from two bales of tow 102a and 102b, and continuously advances in a longitudinal direction L. Each advancing web of tow 100a and 100b is bloomed by a blooming device 104 which spreads out the fibres in a transverse direction. Each web of the transversely spread fibres then enters a plasticising station 106, which sprays plasticiser onto each web of advancing transversely spread fibrous tow to form two webs of plasticised filamentary tow. The plasticiser is sprayed onto the surface of the fibres making up the filamentary tow. The plasticiser is triacetin, although it will be appreciated that other plasticisers may be suitable. The two webs of plasticised filamentary tow are gathered together in a gathering device 108 to form a single web of plasticised filamentary tow. The web of plasticised filamentary tow continues to advance longitudinally and enters a shaping element 110. The shaping element 110 shapes the tow into a longitudinally extending rod of filtering material through which extends a longitudinally extending channel.

[0083] The shaping element comprises a hollow cylindrical chamber (die) formed from a metal material such as brass or stainless steel, into which the plasticised tow advances. The chamber has an inner surface which defines a hollow cylinder extending in the longitudinal direction L. The inner surface may have a circumference between 14 mm and 27 mm. As the tow advances into the chamber, the tow is shaped against the inner surface of the chamber to form a longitudinally extending cylindrical rod of filtering material.

[0084] The shaping element 110 also includes a mandrel, which is shown in FIGS. 2 and 3. The mandrel extends in the longitudinal direction L within the centre of the chamber.

[0085] As shown in FIG. 2, the shaping rod (mandrel) 200 includes a frustoconical section 202 from which extends a cylindrical rod 204. The cylindrical rod 204 having an outer surface 206 and a cavity (not shown). A portion of the cylindrical rod located near to the free end of the cylindrical rod 204 includes a plurality of holes 208 (for example four sets of six equally spaced holes) which extend through the outer surface 206 into the cavity. The plurality of holes are regularly spaced around the entire circumference of the outer surface of the mandrel. The mandrel may be made from any suitable metal, such as brass or stainless steel.

[0086] Returning to FIG. 1, as the web of plasticised tow advances into the shaping element 110, the plasticised tow is pressed against the outer surface of the cylindrical rod 204. The cylindrical rod 204 thereby forms a cylindrical channel within the longitudinally extending rod of filtering material. The cylindrical rod 204 being cylindrical means that a substantially cylindrical channel is formed within the rod of filtering material. It will be appreciated that other shaped rods 204 are possible, such as a rod having a triangular, oval or star shaped cross section. The cross sectional shape and diameter of the rod 204 will determine the cross sectional shape and the diameter of the channel formed in the longitudinally extending rod of filtering material. The cylindrical rod 204 may have a diameter from 0.5 mm to 10 mm, for example from 1 mm to 8 mm, for example from 1 mm to 4 mm, for example from 4 mm to 8 mm, for example from 3 mm to 6 mm.

[0087] The mandrel 200 may be aligned centrally within the chamber of the shaping element 110. Central alignment of the mandrel 200 will mean that the channel formed in the longitudinally extending rod is positioned centrally within the longitudinally extending rod of filtering material.

[0088] It is possible for the mandrel 200 to include more than one cylindrical rod 204, for example two, three, or four cylindrical rods, which will thereby form multiple channels in the rod of filtering material. In such a configuration, the mandrel may include two, three or four pins which protrude longitudinally to thereby enable two, three or four channels to form in the filtering material.

[0089] The mandrel 200 additionally applies an additive, in the form of a menthol composition, to the continuously advancing filtering material. Additive is pumped from an external reservoir 112 and is carried by a pipe 114 to the mandrel. The pipe 114 connects to the frustoconical section 202 of the mandrel 200. The additive passes through the cavity within the mandrel and exits the mandrel through the plurality of holes 208. As the additive exits the holes 208, the additive forms a spray. The additive spray is directed towards the filtering material, and the additive penetrates throughout the filtering material. The additive may also form a layer on the inner surface of the filtering material that defines the channel.

[0090] As set out above, the plurality of holes extend around the entire circumference of the cylindrical rod 204 which means that the additive can be applied in many directions, so that the additive is applied throughout the filtering material.

[0091] The menthol composition includes menthol and a solvent such as propylene glycol. It will be appreciated that the menthol composition could also include pure menthol without a solvent.

[0092] Superheated steam is applied directly to the filtering material within the shaping element chamber via steam inlet pipes which pass through the exterior of the shaping element. Superheated steam acts to cure the plasticised filtering material as it is shaped by the shaping element. The curing hardens the filtering material such that the shape of the rod of filtering material and the channel shape are well defined. The superheated steam is applied directly to the outer surface of the longitudinally extending rod of filtering material as it is formed by the shaping element chamber.

[0093] Surprisingly, the applicant has found that despite the presence of steam in the shaping element, high menthol loadings can be achieved and the menthol remains incorporated in the filtering material over time, as is demonstrated in examples 1 and 2.

[0094] After the longitudinally extending rod of filtering material exits the shaping element, the rod continues to advance and is cooled by jets of air 116 and is cut by a rotary cutter 118 to form filter elements or mouthpieces.

[0095] Before being cut, the longitudinally extending rod of filtering material may be wrapped with a paper wrapper.

[0096] The filter elements or mouthpieces may be assembled into a multiple rod comprising a plurality of filter elements or mouth pieces joined end to end in a mirror image relationship.

[0097] The filter elements or mouthpieces may be assembled into a smoking article using techniques well known in the art.

[0098] FIG. 3 is a perspective view of a filter element or mouthpiece according to the invention.

[0099] The filter element or mouthpiece 300 shown in FIG. 3 may be made by the method described above.

[0100] The filter element or mouthpiece 300 comprises a longitudinally extending core 302 of filtering material wherein the longitudinally extending core 302 has an outer surface 304 and an inner surface 306. The filtering material comprises cellulose acetate filamentary tow and a plasticiser such as triacetin. The filter element or mouthpiece also includes a channel 308 which extends from an end of the core, the channel being defined by the inner surface of the core. The channel includes a layer of menthol disposed on the inner surface of the core. The core 302 also includes menthol which is dispersed throughout the filtering material. The filter element or mouth piece includes menthol in an amount of around 6 mg per filter element/mouthpiece

[0101] The filter element or mouthpiece 300 may form part of a smoke filter suitable for a tobacco smoking article or non-tobacco smokable material such as marijuana or hemp. Additionally, the filter element or mouthpiece may be used in heat not burn or e-cigarette type devices.

EXAMPLES

Example 1

[0102] Filter elements were made according to the process described above and illustrated in FIG. 1.

[0103] The filter elements included a longitudinally extending core of cellulose acetate filamentary tow having an inner surface and an outer surface, in which the inner surface defines a cylindrical channel which extends from an end of the filter element. The core was formed from two bales of cellulose acetate tow having denier 5.0Y30.

[0104] The filtering material included menthol which was applied according to the method of the invention. The menthol was applied as a liquid solution which included menthol and propylene glycol. The filtering material included triacetin as a plasticiser in an amount of 19.7% by total weight of the filtering material and plasticiser, which was applied according to the process of the invention. The cylindrical channel had a diameter of 5 mm. The filter element had a length of 120 mm.

[0105] The filtering elements were analysed in ten batches. Each batch included 4520 filter elements. From each batch, five multi segment filters were assembled, each having 6 filter elements. The five multisegment filters from each batch were analysed using gas chromatography and the menthol loading was measured over the course of 32 days. Average menthol loadings were calculated based on the measurements in each batch at each time point. Additionally, the filter circumference of 10 multisegment filters from each batch was measured using a quality testing machine (QTM3 (laser gauge) Cerulean). The results are set out in table 1 below.

TABLE-US-00001 TABLE 1 Average menthol loading Circumference Day (g per 100 filters) (mm) 1 2.54 24.50 7 2.66 24.53 11 2.62 24.49 14 2.79 24.47 21 2.49 24.50 25 2.58 24.47 32 2.54 24.48

[0106] As shown in table 1, the tested filters include a high and desirable menthol loading on day 1 which was above the target loading of 2.52. The menthol loading stayed fairly constant until day 32 and no significant decrease in menthol loading was observed.

[0107] Circumference also stayed constant between day 1 and 32, and no significant circumference growth was observed.

Example 2

[0108] Filter elements were made according to the process described above and illustrated in FIG. 1.

[0109] The filter elements included a longitudinally extending core of cellulose acetate filamentary tow having an inner surface and an outer surface, in which the inner surface defines a star shaped channel which extends from an end of the filter element. The core was formed from two bales of cellulose acetate tow having denier 5.0Y30.

[0110] The filtering material included menthol which was applied according to the method of the invention. The menthol was applied as a liquid solution which included menthol and propylene glycol. The filtering material included triacetin as a plasticiser in an amount of 19.7% by total weight of the filtering material and plasticiser, which was applied according to the process of the invention. The cylindrical channel had a diameter of 5 mm. The filter element had a length of 120 mm.

[0111] The filtering elements were analysed in ten batches. Each batch included 4520 filter elements. From each batch, five multi segment filters were assembled each having 6 filter elements. The five multisegment filters from each batch were analysed using gas chromatography and the menthol loading was measured over the course of 32 days. Average menthol loadings were calculated based on the measurements in each batch at each time point. Additionally, the filter circumference of 10 filter elements from each batch was measured using a quality testing machine (QTM3 (laser gauge) Cerulean). The results are set out in table 2 below.

TABLE-US-00002 TABLE 2 Average menthol loading Circumference Day (g per 100 filters) (mm) 1 2.51 24.56 2 2.60 24.63 8 2.54 24.60 12 2.57 24.58 15 2.64 24.57 22 2.44 24.57 26 2.65 24.57 33 2.49 24.58

[0112] As shown in table 2, the tested filters include a high and desirable menthol loading on day 1. The menthol loading stayed fairly constant until day 33 and no significant decrease in menthol loading was observed.

[0113] Circumference also stayed constant between day 1 and 33, and no significant circumference growth was observed.