Aerosol Generating Device with Environmentally Optimised Filter

Abstract

An aerosol generating device includes a rod of aerosol generating material and a filter rod, and tipping paper. The filter rod includes a first filter portion and a second filter portion. The first filter portion includes acetate tow and is positioned at a mouth end of the aerosol generating device. The second filter portion is biodegradable and extends from the first filter portion to the rod of aerosol generating material. The tipping paper surrounds the filter rod and a part of the rod of aerosol generating material. The second filter portion encloses a volume which is more than 50% of a combined volume enclosed by the first and second filter portions. The tipping paper includes a line of weakening extending from the mouth end towards the rod of aerosol generating material so that at least a portion of the tipping paper can be opened, and preferably removed, by a user.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/EP2020/059003, filed Mar. 30, 2020, published in English, which claims priority to European Application No. 19167618.8 filed Apr. 5, 2019, the disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a filter for an aerosol generating device.

Conventional cigarettes and currently available heat-not-burn tobacco sticks comprise a tobacco containing rod, a filter, and tipping paper. Acetate tow is often chosen as a filter material as it is able to effectively filter substances such as tar and nicotine without spoiling the cigarette's flavour or aroma. However, it is known to be resistant to biodegradation so that acetate tow filters may take years to break down when disposed.

Accordingly, an object of the present invention is to accelerate the biodegradation of filters, especially those comprising acetate as a main constituent, in order to reduce the environmental impact of cigarette, heat-not-burn stick, or, generally speaking, aerosol generating device disposal, without impacting the smoking experience of the consumer.

US 2014/224268 A1 relates to a smoking article filter. However, the filter includes a polymer insert, which causes difficulty in terms of positioning and alignment during filter manufacture and the combining of the filter components.

In addition, the plastic insert does not promote degradability of filter as a whole after use, and thus does not reduce environmental impact sufficiently.

WO 2009/016513 A2 relates to degradable cigarette filters.

EP 2 002 737 A1 relates to a smoking article and filter. However, the smoking article does not sufficiently improve the degradability of the filter material. In particular, the article requires the introduction of a thread or like in the tearing band which results in the use of additional material and increases the processing difficulty during filter manufacture, requiring registration in the tipping position or pre-processing of the whole tipping paper reels to adhere the threads and form the weakening lines. This significantly increases the cost of filter manufacture compared to the present invention.

BRIEF SUMMARY OF THE INVENTION

According to an aspect of the invention there is provided an aerosol generating device comprising: a rod of aerosol generating material; a first filter portion which comprises acetate tow and is positioned at a mouth end of the aerosol generating device; a second filter portion which is biodegradable and is positioned between the first filter portion and the rod of aerosol generating material; and tipping paper surrounding the first filter portion and the second filter portion, wherein the tipping paper comprises a line of weakening so that at least a portion of the tipping paper can be removed by a user.

In this way, biodegradation of a cigarette filter is accelerated following its disposal. The two-piece filter arrangement carries two significant advantages: the biodegradable portion accelerates filter break down and the acetate tow portion ensures the cigarette taste, aroma and visible filter aesthetics remain comparable to conventional cigarettes. Moreover, the introduction of a line of weakening to the tipping paper allows the consumer to easily remove the outer material prior to disposal of the cigarette. It has been found that tipping paper provides a barrier to the ingress of liquid and biological elements to the filter, which would otherwise accelerate filter degradation. Hence, by providing the consumer with the ability to remove this barrier, biodegradation can be accelerated and the environmental impact of cigarette disposal reduced.

The second filter portion may be a paper-based material. Advantageously, paper-based filter materials, such as “Ochre”, have been found to biodegrade at a faster rate than acetate tow. However, paper-based materials often perform poorly in consumer taste tests compared with acetate tow, and exhibit an off-white colour. Therefore, a two-piece arrangement of filter elements, with the acetate tow material situated at the visible mouth end, provides improved biodegradability without affecting the filter aesthetic and only having a minimal effect on smoking taste.

Preferably, the line of weakening in the tipping paper extends in an axial direction with respect to the main longitudinal axis of the aerosol generating device. In this way, application of a ripping force along the length of the line of weakening results in a complete and efficient partitioning of the tipping paper and fully exposes the underlying filter elements.

Typically, there are two parallel lines of lines of weakening in the tipping paper. In this way, a strip of tipping paper may be removed to allow significant ingress of liquid and biological elements to the filter.

A tab may be formed in the tipping paper between the two parallel lines of weakening to allow the tipping paper to be gripped by a user. In this way, the consumer is provided with a greater ease of removal of the tipping paper.

Preferably, two notches are provided in the tipping paper at the mouth end respectively adjacent the parallel lines of weakening, and wherein the tab is provided between the notches. In this way, the tab may be gripped and a ripping force applied by the consumer. The applied force is concentrated at the notch tips thereby improving the reliability of the ripping process by ensuring the rips propagate along the lines of weakening.

Preferably, the line of weakening is a line of perforations. In this way, the line of weakening can easily be applied to the tipping paper, using a versatile procedure such as laser perforation or the use of a perforating wheel.

In one example, the aerosol generating device may be a smoking article such as a tobacco rod. In other examples, the aerosol generating device may be a heat-not-burn stick.

According to another aspect of the invention, there is provided a method of producing an aerosol generating device, comprising: providing a rod of aerosol generating material; providing a first filter portion, which comprises acetate tow, at a mouth end of the aerosol generating device; providing a second filter portion, which is biodegradable, between the first filter portion and the rod of aerosol generating material; providing tipping paper surrounding the first filter portion and the second filter portion; and applying a line of weakening to the tipping paper so that at least a portion of the tipping paper can be removed by a user.

Preferably, the line of weakening is a line of perforations. In one example, the line of perforations may be created using a laser. In another example, the line of perforations may be created using a perforating wheel.

The line of weakening may be applied to the tipping paper after the tipping paper is attached to the aerosol generating device. Alternatively, the line of weakening may be applied to the tipping paper before the tipping paper is attached to the aerosol generating device.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are now described, by way of example, with reference to the drawings, in which:

FIG. 1 is a perspective view of a cigarette including an illustrative cut-away section in an embodiment of the invention;

FIG. 2 is an exploded view of the cigarette depicted in FIG. 1;

FIG. 3A is a side view of the cigarette depicted in FIG. 1;

FIG. 3B is a cross-sectional side view of the cigarette depicted in FIG. 1;

FIG. 4A is a cross-sectional side view of an arrangement of cigarette elements used in the production of a cigarette in an embodiment of the invention; and

FIG. 4B is a side view of an arrangement of cigarette elements used in the production of a cigarette in an embodiment of the invention.

DETAILED DESCRIPTION

FIGS. 1, 2, 3A and 3B are schematic views of a smoking article 10, in this case a cigarette 10, in an embodiment of the invention. The reference to a smoking article 10 shall in the context of the present invention and description not be construed as limited to cigarettes or other kinds of tobacco products requiring burning of tobacco material to generate an aerosol inhaled by a user. The terms smoking article shall to the contrary apply and be construed to also encompass any kind of aerosol generating devices making use of tobacco containing substrates, be it plain tobacco leaves, tobacco cut-filler, reconstituted tobacco or tobacco extracts in all forms, for generating an inhalable aerosol through any kind of heating technique. It may in particular encompass any heat-not-burn tobacco containing consumable device used in connection with a filter for consumption by users.

The cigarette 10 comprises a smoking rod 12 connected to a filter 14. The filter 14 comprises two cylindrical filter portions: a first filter portion 16 positioned at the mouth end 15 of the filter 14 and a second filter portion 18 positioned between the first filter portion 16 and the smoking rod 12.

The first filter portion 16 comprises acetate tow material and the second filter portion 18 comprises a biodegradable material that degrades at a faster rate than acetate tow. In one example, the second filter portion 18 may comprise the paper-based material “Ochre”, which has been found to degrade more rapidly than filters constructed with acetate tow. In other examples, the second filter portion 18 may comprise any other filter material that biodegrades more rapidly than acetate tow.

The first filter portion 16 and the second filter portion 18 each enclose a respective volume. The second filter portion 18 constitutes, according to the invention, a larger proportion of the combined filter 14 volume. The second filter portion 18 thus constitutes more than 50% of the combined filter 14 volume. Preferably at least 75% and up to 95% thereof. In a preferred embodiment the second filter portion 18 forms about 85% of the total filter volume, the remainder (i.e. 15%) being formed by the first filter portion 16. In this way, the second filter portion 18 provides a greater contribution to the overall degradation rate of the filter 14 than the acetate tow first filter portion 16, thereby accelerating overall degradation. However, it will be appreciated by the skilled person that the relative proportions of the two filter 14 portions may be configured according to specific smoking requirements in consideration of the above-defined principles. In this way, other filter properties such as taste, pressure drop, filtration characteristics, degradation rate, and cost may be controlled by altering the relative portions of the first filter portion 16 and the second filter portion 18.

By situating the acetate tow first filter portion 16 at the mouth end 15, the exposed face of the filter 14 is seen to resemble that of a conventional cigarette. Therefore, consumer perception of the cigarette 10 remains unaffected and a similar taste experience is provided.

The filter 14 is wrapped in tipping paper 20, wherein the tipping paper 20 conforms to the shape of the underlying filter 14. The tipping paper 20 comprises at least one, and preferably as represented two parallel lines of perforations 22 and 23 which extend in an axial direction with respect to the main longitudinal axial of the cigarette 10. Two notches 24 and 25 are provided at the mouth end 15 of each perforation line 22 and 23 and a tab 26 is formed between the notches 24 and 25.

The consumer is able to grip the tab 26 and apply a ripping force along the perforation lines 22 and 23 resulting in the removal of a strip of tipping paper 20 from the filter 14. In this way, following disposal of the cigarette 10, biodegradation of the filter 14 is accelerated as the ingress of liquid and biological components to the filter 14 is no longer blocked by the tipping paper 20.

There are many other possible perforation arrangements, as will be appreciated by the skilled person. In one example, the perforations may extend circumferentially or helically around the filter 14, or there may only be one line of perforations. In another example, the notches 24 and 25 and tab 26 may be positioned at the other end of the filter 14, adjacent to the smoking rod 12. In another example, the notches 24 and 25 or tab 26 may be absent.

As will be appreciated by the skilled person, the lines of perforations may comprise any alternative form of line of weakening, wherein the line of weakening enables the tipping paper 20 to easily be ripped by the consumer. In one example, the line of weakening may comprise a portion of tipping paper 20 having a thickness that is thinner than the rest of the tipping paper 20. In another example, the line of weakening may comprise a chemically weakened portion. In another example, the line of weakening may comprise a radiatively weakened portion. In another example, the line of weakening may comprise a mechanically weakened portion. In another example, the line of weakening may comprise a portion of tipping paper 20 made from a weaker material than the rest of the tipping paper 20.

In embodiments of the invention, the lines of perforations 22, 23 extend from the mouth end towards the smoking rod 12 over more than 50% of the length of the tipping paper along the longitudinal axis of the smoking article. Thus, a user can ensure, upon breaking of the tipping paper, that both the first and second filter portions 16, 18 get exposed to the outside environment and consequently that water ingress is permitted into the biodegradable second filter portion 18.

Preferably, the lines of perforations 22, 23 extend from the mouth end towards the smoking rod 12 over the entire length of the tipping paper 20, such that a user can fully open the tipping paper to release both filter portions 16, 18 free and fully expose it to the outside environment after smoking the article 1.

The smoking rod 12 contains shredded tobacco 28. A number of other products and aerosol generating ingredients may be provided within the smoking rod 12, as will be appreciated by a person skilled in the art.

The filter 14 is wrapped in tipping paper 20 which extends beyond the length of the filter 14. In this way, the tipping paper 20 also wraps around a portion of the smoking rod 12, thereby providing secure attachment of the filter 14 to the smoking rod 12. In an alternative embodiment, the tipping paper 20 may be the same length as the filter 14. In one example, the tipping paper 20 may be fed from a reel and attached to the cigarette 10 during manufacture.

The filter 14 is wrapped in plug wrap paper 30 which is provided between the filter 14 and the tipping paper 20. The plug wrap paper 30 is used, as commonly known in cigarette filter making, to hold the two filter elements 16, 18 together firmly during manufacture and use, in particular to ensure proper filter 14 integrity upon attachment to the smoking rod 12 with the tipping paper 20. In one example, the tipping paper 20, plug wrap paper 30, first filter portion 16 and the second filter portion 16 may be joined using an adhesive.

The perforations of the perforation lines 22 and 23 only penetrate the tipping paper 20, and do not extend through the plug wrap paper 30. This ensures that filter 14 properties such as the pressure drop on inhalation and substance permeability are unaffected by the presence of the perforations. In this way, a comparable smoking experience to a conventional cigarette is provided to the consumer.

In alternative embodiments, the perforations may extend through the plug wrap paper 30 to enable the removal of both the tipping paper 20 and the plug wrap paper 30. This would provide an even greater level of liquid and biological ingress to the filter 14, thereby further accelerating degradation.

The perforation lines 22 and 23 may be created using methods such as laser perforation, use of perforating wheel, or any other suitable perforation technique. In one example, the perforations may be created prior to application of the tipping paper 20 to the filter 14. In an alternative example, the perforations may be created after application of the tipping paper 20 to the filter 14.

FIGS. 4A and 4B show a side view and cross-sectional side view respectively of an arrangement of cigarette elements used in the production of a cigarette in an embodiment of the invention.

The arrangement comprises a smoking rod 12, a second filter portion 18, a first filter portion 16, another second filter portion 16, and another smoking rod 12 provided respectively in an abutting sequence. Tipping paper 20 is wrapped around the arrangement and a laser, or any other suitable tool, used to create two parallel lines of perforations 22 and 23 extending in an axial direction with respect to the main longitudinal axis of the arrangement. The laser is also used to form two notches 24 and 25 in the tipping paper 20: one at the centre of each line of perforation with respect to the main longitudinal axis of the arrangement. In alternative examples, the lines of perforations 22 and 23 may be any other lines of weakening, such as a thinner portion of tipping paper 20.

A cutting device, such as a saw or laser, can be used to cut through the mirror plane lying perpendicular to the longitudinal axis of the arrangement, thereby producing two cigarettes 10, each with two parallel lines of perforations 22 and 23 and two notches 24 and 25 provided at their mouth ends 15, as shown in FIGS. 1, 2, 3A and 3B.

Claims

1. An aerosol generating device comprising:

a rod of aerosol generating material;

a filter rod, the filter rod comprising: a first filter portion which comprises acetate tow and is positioned at a mouth end of the aerosol generating device; a second filter portion which is biodegradable and which extends from the first filter portion to the rod of aerosol generating material; and

tipping paper surrounding the filter rod and a part of the rod of aerosol generating material such that the filter rod and the rod of aerosol generating material are coupled together along a common longitudinal axis,

wherein the second filter portion encloses a volume which is more than 50% of a combined volume enclosed by the first and second filter portions, and

wherein the tipping paper comprises a line of weakening extending from the mouth end towards the rod of aerosol generating material so that at least a portion of the tipping paper can be opened by a user.

2. The aerosol generating device of claim 1, wherein the second filter portion is a paper-based material.

3. The aerosol generating device of claim 1, wherein the line of weakening in the tipping paper extends over more than 50% of a length of the tipping paper along the longitudinal axis.

4. The aerosol generating device of claim 1, wherein the line of weakening in the tipping paper extends along an entire length of the tipping paper along the longitudinal axis.

5. The aerosol generating device of claim 1, further comprising another line of weakening parallel to the line of weakening in the tipping paper.

6. The aerosol generating device of claim 5, wherein a tab is formed in the tipping paper between the two parallel lines of weakening to allow the tipping paper to be gripped by a user.

7. The aerosol generating device of claim 6, wherein two notches are provided in the tipping paper at the mouth end respectively adjacent the parallel lines of weakening, and wherein the tab is provided between the notches.

8. The aerosol generating device of claim 1, wherein the line of weakening is a line of perforations.

9. The aerosol generating device of claim 1, wherein the aerosol generating device is a smoking article.

10. A method of producing an aerosol generating device, comprising:

providing a rod of aerosol generating material;

providing a filter rod, the filter rod comprising: a first filter portion which comprises acetate tow and is positioned at a mouth end of the aerosol generating device; a second filter portion which is biodegradable and which extends from the first filter portion to the rod of aerosol generating material and which encloses a volume which is more than 50% of a combined volume enclosed by the first and second filter portions;

providing tipping paper surrounding the filter rod and a part of the rod of aerosol generating material such that the filter rod and the rod of aerosol generating material are coupled together along a common longitudinal axis; and

applying a line of weakening to the tipping paper extending from the mouth end towards the rod of aerosol generating material so that at least a portion of the tipping paper can be opened, and preferably removed, by a user.

11. The method of claim 10, wherein the line of weakening is a line of perforations.

12. The method of claim 11, wherein the line of perforations is created using a laser or a perforating wheel.

13. The method of claim 10, wherein the line of weakening is applied to the tipping paper before the tipping paper is attached to the aerosol generating device.

14. The method of claim 10, wherein the line of weakening in the tipping paper extends over more than 50% of a length of the tipping paper along the longitudinal axis.

15. The method of claim 10, wherein the line of weakening in the tipping paper extends along an entire length on the tipping paper along the longitudinal axis.

16. The method claim 10, wherein the second filter portion is a paper-based material.

17. The method claim 10, wherein the step of applying the line of weakening comprises applying two lines of weakening extending in parallel from the mouth end towards the rod of aerosol generating material.

18. The method according to claim 17, wherein two notches are provided in the tipping paper at the mouth end respectively adjacent the parallel lines of weakening, and wherein a tab is provided between the notches.

19. The method of claim 10, wherein the line of weakening is applied to the tipping paper after the tipping paper is attached to the aerosol generating device.