This application claims priority from UK patent application number GB1816120.8 filed on 3 October 2018, and UK patent application number GB1817559.6 filed on 29 October 2018, the content of both the aforementioned patent applications being incorporated herein.

Field of the Disclosure

The present disclosure relates to a web of plant material, a consumable for use in a smoking substitute system and particularly, although not exclusively, to a heat-not-burn (HNB) consumable, wherein the consumable comprises a gathered web of plant material. The present disclosure also relates to a method of forming the web of plant material.

Background

The smoking of tobacco is generally considered to expose a smoker to potentially harmful substances. It is generally thought that a significant amount of the potentially harmful substances are generated through the heat caused by the burning and/or combustion of the tobacco and the constituents of the burnt tobacco in the tobacco smoke itself.

Conventional combustible smoking articles, such as cigarettes, typically comprise a cylindrical rod of tobacco comprising shreds of tobacco which is surrounded by a wrapper, and usually also a cylindrical filter axially-aligned in an abutting relationship with the wrapped tobacco rod. The filter typically comprises a filtration material which is circumscribed by a plug wrap. The wrapped tobacco rod and the filter are joined together by a wrapped band of tipping paper that circumscribes the entire length of the filter and an adjacent portion of the wrapped tobacco rod. A conventional cigarette of this type is used by lighting the end opposite to the filter, and burning the tobacco rod. The smoker receives mainstream smoke into their mouth by drawing on the mouth end or filter end of the cigarette.

The shreds (or strips) of tobacco can be formed by shredding a sheet of reconstituted tobacco into strips using a pair of rotating and intermeshing stacks of cutting discs. One problem with using such shreds/strips of tobacco is that the shreds/strips can break and, being untethered to the rest of the tobacco shreds, can fold up to create a blockage within the shredding machinery which will require downtime in the production process whilst the blockage is cleared and the sheet re-threaded between the cutting discs. Providing an un-slit bridge running transversely across the sheet of tobacco to connect and tether the shreds is known but this leads to irregularities in the distribution/density of the tobacco within the cylindrical rod of tobacco. Combustion of organic material such as tobacco is known to produce tar and other potentially harmful byproducts. There have been proposed various smoking substitute systems (or“substitute smoking systems”) in order to avoid the smoking of tobacco.

Such smoking substitute systems can form part of nicotine replacement therapies aimed at people who wish to stop smoking and overcome a dependence on nicotine.

Smoking substitute systems include electronic systems that permit a user to simulate the act of smoking by producing an aerosol (also referred to as a“vapour”) that is drawn into the lungs through the mouth (inhaled) and then exhaled. The inhaled aerosol typically bears nicotine and/or flavourings without, or with fewer of, the odour and health risks associated with traditional smoking.

In general, smoking substitute systems are intended to provide a substitute for the rituals of smoking, whilst providing the user with a similar experience and satisfaction to those experienced with traditional smoking and with combustible tobacco products. Some smoking substitute systems use smoking substitute articles that are designed to resemble a traditional cigarette and are cylindrical in form with a mouthpiece at one end.

The popularity and use of smoking substitute systems has grown rapidly in the past few years. Although originally marketed as an aid to assist habitual smokers wishing to quit tobacco smoking, consumers are increasingly viewing smoking substitute systems as desirable lifestyle accessories.

There are a number of different categories of smoking substitute systems, each utilising a different smoking substitute approach.

One approach for a smoking substitute system is the so-called "heat not burn" (“HNB”) approach in which tobacco (rather than an“e-liquid”) is heated or warmed to release vapour. The tobacco may be leaf tobacco or reconstituted tobacco. The vapour may contain nicotine and/or flavourings. In the HNB approach the intention is that the tobacco is heated but not burned, i.e. the tobacco does not undergo combustion.

A typical HNB smoking substitute system may include a device and a consumable. The consumable may include the tobacco material. The device and consumable may be configured to be physically coupled together. In use, heat may be imparted to the tobacco material by a heating element of the device, wherein airflow through the tobacco material causes moisture in the tobacco material to be released as vapour. A vapour may also be formed from a carrier in the tobacco material (this carrier may for example include propylene glycol and/or vegetable glycerine) and additionally volatile compounds released from the tobacco. The released vapour may be entrained in the airflow drawn through the tobacco. As the vapour passes through the consumable (entrained in the airflow) from an inlet to a mouthpiece (outlet), the vapour cools and condenses to form an aerosol for inhalation by the user. The aerosol will normally contain the volatile compounds.

In HNB smoking substitute systems, heating as opposed to burning the tobacco material is believed to cause fewer, or smaller quantities, of the more harmful compounds ordinarily produced during smoking. Consequently, the HNB approach may reduce the odour and/or health risks that can arise through the burning, combustion and pyrolytic degradation of tobacco.

There is a need for an improved design of HNB consumables to enhance the user experience and improve the function of the HNB smoking substitute system.

The present disclosure has been devised in the light of the above considerations.

Summary of the Disclosure

At its most general, the present disclosure relates to a web of plant material, an aerosol-forming article e.g. a consumable for use in a smoking substitute system and particularly, although not exclusively, to a heat- not-burn (HNB) consumable, wherein the article/consumable comprises a gathered web of plant material. The present disclosure also relates to a method of forming the web of plant material.

Accordingly, in a first aspect, there is provided a web of plant material having a plurality of longitudinally- extending shreds of plant material wherein there is a plurality of transverse bridge portions each extending between and joining two or more of the shreds, wherein none of the bridge portions extend across the entire transverse width of the web.

By providing a web comprising shreds of plant material with adjacent shreds connected by bridge portions that do not extend across the entire transverse width of the web, it is possible to provide a web that can subsequently be gathered to form a cylindrical rod having improved uniformity in thermal transfer throughout the plant material. The known webs having a single bridge portion which spans the entire web in a transverse direction, result in a band or pad of gathered, un-slit plant material within the cylindrical rod and this bad/pad results in reduced packing of the plant material and a lack of uniformity in thermal transfer. The present disclosure provides a plurality of transverse bridge portions having a shorter transverse dimension and thus avoids the incorporation of an extensive pad/band of un-slit plant material. This allows denser packing of the plant material after gathering and more controlled, consistent heat transfer between the shreds of plant material.

Optional features will now be set out. These are applicable singly or in any combination with any aspect. In preferred embodiments, adjacent bridge portions are longitudinally spaced from one another. The longitudinal spacing between adjacent bridge portions results in adjacent bridge portions being unaligned in the transverse direction.

In preferred embodiments, adjacent transverse bridge portions are completely unaligned in the transverse direction such that there is no longitudinal overlap of adjacent bridge portions in the transverse direction.

In some embodiments, each transverse bridge portion spans ten or fewer e.g. nine or fewer e.g. eight or seven or six or five or four or three or fewer immediately adjacent shreds of plant material. Preferably each transverse bridge portion spans only two adjacent shreds of plant material.

The web of plant material may have a plurality of longitudinally-extending discontinuous slits dividing the plant material into the plurality of longitudinally-extending shreds, each discontinuous slit comprising a respective discontinuity forming the respective transverse bridge portion between adjacent shreds.

The discontinuity (or interruption) in a discontinuous slit results in a transverse bridge portion formed of unslit plant material that joins adjacent shreds of tobacco.

The web may have a first lateral end and an opposing second lateral end with the slits and shreds running longitudinally between the first and second lateral ends.

References to“the transverse direction” and uses of the terms “transverse” and/or“transversely” are intended to refer to a direction which is perpendicular to the longitudinal direction i.e. perpendicular to the direction in which the slits within the web of plant material extend and perpendicular to the direction in which the shreds of plant material extend.

In some embodiments, upon progression along the transverse direction, adjacent bridge portions may get progressively closer to one of the lateral ends of the web. There may be an equal longitudinal spacing between the transverse bridge portions. In these embodiments, the transverse bridge portions are diagonally arranged/offset on the web of plant material.

In other embodiments, each of the plurality of transverse bridge portions (other than the bridge portion at the transverse edge of the web) is closer to one of the lateral ends of the web than its two adjacent bridge portions (i.e. than the two bridge portions on either side of it). In this way, the transverse bridge portions may be randomly arranged on the web of plant material. This longitudinal spacing of the bridge portions may lead to an arrangement where the plurality of bridge portions form a plurality of longitudinally spaced diagonal arrangements which adjacent bridge portions forming part of different diagonal arrangements. The web of plant material may comprise a first group of discontinuous slits wherein all transverse bridge portions within the first group are longitudinally spaced from one another. The first group of discontinuous slits may comprise 10 or fewer, e.g. 9 or fewer, such as 8 or 7 fewer, for example 6 or 5 or 4 transverse bridge portions.

In some embodiments, the discontinuous slits in the first group of discontinuous slits are immediately adjacent each other in a transverse direction.

In other embodiments, there may be one or more continuous slit(s) (i.e. slit(s) without any discontinuities/transverse bridge portions) interposed between adjacent discontinuous slits in the first group of discontinuous slits. There may be a group of immediately adjacent continuous slits.

The web may further comprise a second group of discontinuous slits which may be spaced in a transverse direction from the first group of discontinuous slits by the group of continuous slits. The second group of discontinuous slits may be identical to the first group of discontinuous slits i.e. with the transverse bridge portions aligned in the transverse direction between the first and second group of discontinuous slits.

The group of continuous slits may include a greater number of slits than the groups(s) of discontinuous slits

The transverse spacing between adjacent slits in the first and/or second group of discontinuous slits and/or between adjacent slits in the first group of continuous slits may be substantially equal.

The transverse spacing between the slits may be equal to greater than 0.5mm. The transverse spacing between the slits may be equal to or less than 2mm, e.g. equal to or less than 1 .5mm. The transverse spacing between the slits may be around 1 mm.

In this way, the web of material preferably comprises a plurality of shreds of tobacco all having an equal width i.e. between 0.5 and 2mm, preferably between 0.5 and 1.5mm e.g. around 1 mm.

Where the transverse bridge portion spans only two adjacent shreds of plant material, the transverse bridge portion has a transverse dimension of between 1 mm and 4mm, preferably around 2mm.

In some embodiments, the longitudinal dimension of the discontinuity and thus the longitudinal dimension of the transverse bridge portions is equal to or greater than 1 mm, e.g. equal to or greater than 2mm or 3mm. In some embodiments, the longitudinal dimension of the discontinuity and thus the longitudinal dimension of the transverse bridge portions is equal to or less than 6mm, e.g. equal to or less than 5mm. In some embodiments, the longitudinal dimension of the discontinuity and thus the longitudinal dimension of the transverse bridge portions is around 4mm. In some embodiments, the web of material may have a transverse dimension equal to or less than 200mm, e.g. equal to or less than 150mm such as equal or less than 140mm.

In some embodiments, the web of material may have a transverse dimension equal to or greater than 100mm, e.g. greater than 1 10mm such as greater than 120mm.

The web material may have a transverse dimension of around 130mm. The web material may be formed of 129 slits and 130 shreds having a transverse width of 1 mm each.

The web material may have a sheet weight greater than or equal to 100 g/m ² , e.g. greater than or equal to 1 10 g/m ² such as greater than or equal to 120 g/m ² .

The web material may have a sheet weight less than or equal to 300 g/m ² e.g. less than or equal to 250 g/m ² or less than or equal to 200 g/m ² .

The web material may have a sheet weight of between 120 and 190 g/m ² .

In a second aspect, there is provided an aerosol-forming article (e.g. a smoking substitute article such as an HNB consumable) comprising an aerosol-forming substrate comprising a web of plant material according to the first aspect, the web being gathered and at least partially circumscribed by a wrapping layer.

The aerosol-forming article is preferably a heat-not-burn (HNB) consumable.

The aerosol-forming substrate is capable of being heated to release at least one volatile compound that can form an aerosol. The aerosol-forming substrate may be located at the upstream end of the article/consumable.

As used herein, the terms’’upstream” and“downstream” are intended to refer to the flow direction of the vapour/aerosol i.e. with the downstream end of the article/consumable being the mouth end or outlet where the aerosol exits the article/consumable for inhalation by the user. The upstream end of the article/consumable is the opposing end to the downstream end.

In order to generate an aerosol, the aerosol-forming substrate comprises at least one volatile compound that is intended to be vaporised/aerosolised and that may provide the user with a recreational and/or medicinal effect when inhaled. Suitable chemical and/or physiologically active volatile compounds include the group consisting of: nicotine, cocaine, caffeine, opiates and opoids, cathine and cathinone, kavalactones, mysticin, beta-carboline alkaloids, salvinorin A together with any combinations, functional equivalents to, and/or synthetic alternatives of the foregoing. The plant material forming the web in the first and second aspects may comprise least one plant material selected from the list including Amaranthus dubius, Arctostaphylos uva-ursi (Bearberry), Argemone mexicana, Arnica, Artemisia vulgaris, Yellow Tees, Galea zacatechichi, Canavalia maritima (Baybean), Cecropia mexicana (Guamura), Oestrum noctumum, Cynoglossum virginianum (wild comfrey), Cytisus scoparius, Damiana, Entada rheedii, Eschscholzia califomica (California Poppy), Fittonia albivenis, Hippobroma longi flora, Humulus japonica (Japanese Hops), Humulus lupulus (Hops), Lactuca virosa (Lettuce Opium), Laggera alata, Leonotis leonurus, Leonurus cardiaca (Motherwort), Leonurus sibiricus (Honeyweed), Lobelia cardinalis, Lobelia inflata (Indian-tobacco), Lobelia siphilitica, Nepeta cataria (Catnip), Nicotiana species (Tobacco), Nymphaea alba (White Lily), Nymphaea caerulea (Blue Lily), Opium poppy, Passiflora incamata (Passionflower), Pedicularis densiflora (Indian Warrior), Pedicularis groenlandica (Elephant's Head), Salvia divinorum, Salvia dorrii (Tobacco Sage), Salvia species (Sage), Scutellaria galericulata, Scutellaria lateriflora, Scutellaria nana, Scutellaria species (Skullcap), Sida acuta (Wireweed), Sida rhombi folia, Silene capensis, Syzygium aromaticum (Clove), Tagetes lucida (Mexican Tarragon), Tarchonanthus camphoratus, Tumera diffusa (Damiana), Verbascum (Mullein), Zamia latifolia (Maconha Brava) together with any combinations, functional equivalents to, and/or synthetic alternatives of the foregoing.

Preferably, the plant material is tobacco. Any type of tobacco may be used. This includes, but is not limited to, flue-cured tobacco, burley tobacco, Maryland Tobacco, dark-air cured tobacco, oriental tobacco, dark- fired tobacco, perique tobacco and rustica tobacco. This also includes blends of the above mentioned tobaccos.

Any suitable parts of the tobacco plant may be used. This includes leaves, stems, roots, bark, seeds and flowers.

The tobacco may comprise reconstituted tobacco (e.g. slurry recon or paper recon).

The aerosol-forming substrate may comprise at least 50 wt% plant material, e.g. at least 60 wt% plant material e.g. around 65 wt% plant material. The aerosol-forming substrate may comprise 80 wt% or less plant material e.g. 75 or 70 wt% or less plant material.

The aerosol-forming substrate may comprise one or more additives selected from humectants, flavou rants, fillers, aqueous/ non-aq u eous solvents and binders.

Humectants are provided as vapour generators - the resulting vapour helps carry the volatile active compounds and increases visible vapour. Suitable humectants include polyhydric alcohols (e.g. propylene glycol (PG), triethylene glycol, 1 ,2-butane diol and vegetable glycerine (VG)) and their esters (e.g. glycerol mono-, di- or tri-acetate). They may be present in the aerosol-forming substrate in an amount between 1 and 50 wt%.

The humectant content of the aerosol-forming substrate may have a lower limit of at least 1 % by weight of the plant material, such as at least 2 wt %, such as at least 5 wt %, such as at least 10 wt %, such as at least 20 wt %, such as at least 30 wt %, or such as least 40 wt %.

The humectant content of the aerosol-forming substrate may have an upper limit of at most 50 % by weight of the plant material, such as at most 40 wt %, such as at most 30 wt %, or such as at most 20 wt %.

Preferably, the humectant content is 1 to 40 wt % of the aerosol-forming substrate, such as 1 to 20 wt %

Suitable binders are known in the art and may act to bind together the components forming the aerosolforming substrate. Binders may comprise starches and/or cellulosic binders such as methyl cellulose, ethyl cellulose, hydroxy propyl cellulose, hydroxyethyl cellulose and methyl cellulose, gums such as xanthan, guar, arabic and/or locust bean gum, organic acids and their salts such as alginic acid/ sodium alginate, agar and pectins.

Preferably the binder content is 5 to 10 wt% of the aerosol-forming substrate e.g. around 6 to 8 wt%.

Suitable fillers are known in the art and may act to strengthen the aerosol-forming substrate. Fillers may comprise fibrous (non-tobacco) fillers such as cellulose fibres, lignocellulose fibres (e.g. wood fibres), jute fibres and combinations thereof.

Preferably, the filler content is 5 to 10 wt% of the aerosol-forming substrate e.g. around 6 to 9 wt%.

The aerosol-forming substrate may comprise an aqueous and/or non-aqueous solvent. In some embodiments, the aerosol forming substrate has a water content of between 5 and 10 wt% e.g. between 6-9 wt% such as between 7-9 wt%.

The flavourant may be provided in solid or liquid form. It may include menthol, liquorice, chocolate, fruit flavour (including e.g. citrus, cherry etc.), vanilla, spice (e.g. ginger, cinnamon) and tobacco flavour. The flavourant may be evenly dispersed throughout the aerosol-forming substrate or may be provided in isolated locations and/or varying concentrations throughout the aerosol-forming substrate.

The aerosol-forming substrate may be formed in a substantially cylindrical shape such that the article/consumable resembles a conventional cigarette. It may have a diameter of between 5 and 10mm e.g. between 6 and 9mm or 6 and 8mm e.g. around 7 mm. It may have an axial length of between 10 and 15mm e.g. between 1 1 and 14mm such as around 12 or 13mm.

The aerosol-forming substrate is at least partly circumscribed by a wrapping layer e.g. a paper wrapping layer. The wrapping layer may overlie an inner foil layer or may comprise a paper/foil laminate (with the foil innermost).

The article/consumable may comprise at least one filter element. There may be a terminal filter element at the downstream/mouth end of the article/consumable.

The or at least one of the filter element(s) (e.g. the terminal filter element) may be comprised of cellulose acetate or polypropylene tow. The at least one filter element (e.g. the terminal filter element) may be comprised of activated charcoal. The at least one filter element (e.g. the terminal element) may be comprised of paper. The or each filter element may be circumscribed with a plug wrap e.g. a paper plug wrap.

The or each filter element may have a substantially cylindrical shape with a diameter substantially matching the diameter of the aerosol-forming substrate (with or without its associated wrapping layer). The axial length of the or each filter element may be less than 20mm, e.g. between 8 and 15mm, for example between 9 and 13 mm e.g. between 10 and 12mm.

The or at least one of the filter element(s) may be a solid filter element. The or at least one of the filter element(s) may be a hollow bore filter element. The or each hollow bore filter may have a bore diameter of between 1 and 5 mm, e.g. between 2 and 4 mm or between 2 and 3 mm.

There may be a plurality of e.g. two filter elements which may be adjacent one another or which may be spaced apart. Any filter element(s) upstream of the terminal filter element may be at least partly (e.g. entirely) circumscribed by the (paper) wrapping layer.

The terminal filter element (at the downstream end of the article/consumable) may be joined to the upstream elements forming the article/consumable by a circumscribing tipping layer e.g. a tipping paper layer. The tipping paper may have an axial length longer than the axial length of the terminal filter element such that the tipping paper completely circumscribes the terminal filter element plus the wrapping layer surrounding any adjacent upstream element.

The or at least one of the filter elements e.g. the terminal filter element may include a capsule e.g. a crushable capsule (crush-ball) containing a liquid flavourant e.g. any of the flavourants listed above. The capsule can be crushed by the user during smoking of the article/consumable to release the flavourant. The capsule may be located at the axial centre of the terminal filter element. In some embodiments, the article/consumable may comprise an aerosol-cooling element which is adapted to cool the aerosol generated from the aerosol-forming substrate (by heat exchange) before being inhaled by the user.

The aerosol-cooling element will be downstream from the aerosol-forming substrate. For example, it may be between the aerosol-forming substrate and a/the filter element and/or between two filter elements. The aerosol cooling element may be at least partly (e.g. completely) circumscribed by the (paper) wrapping layer.

The aerosol-cooling element may be formed of a plastics material selected from the group consisting of polylactic acid (PLA), polyvinyl chloride (PVC), polyethylene (PE) and polyethylene terephthalate (PET). The aerosol-cooling element may be formed of a crimped/gathered sheet of material to form a structure having a high surface area with a plurality of longitudinal channels to maximise heat exchange and cooling of the aerosol.

The article/consumable may comprise a spacer element that defines a space or cavity or chamber between the aerosol-forming substrate and the downstream end of the article/consumable. The spacer acts to allow both cooling and mixing of the aerosol. The spacer element may comprise a cardboard tube. The spacer element may be at least partly (e.g. entirely) circumscribed by the (paper) wrapping layer.

The spacer element may have an external diameter of between 5 and 10mm e.g. between 6 and 9mm or 6 and 8mm e.g. around 7 mm. It may have an axial length of between 10 and 15mm e.g. between 12 and 14 mm or 13 and 14mm e.g. around 14mm.

In a third aspect, there is provided a smoking substitute system comprising an aerosol-forming article according to the second aspect and a device comprising a heating element.

The device may be a HNB device i.e. a device adapted to heat but not combust the aerosol-forming substrate.

The device may comprise a main body for housing the heating element. The heating element may comprise an elongated e.g. rod, tube-shaped or blade heating element. The heating element may project into or surround a cavity within the main body for receiving the article/consumable described above.

The device and the aerosol-forming article may be configured to permit insertion of the aerosol-forming article into a cavity in the device, and the heating element may be elongate and configured to penetrate the aerosol-forming substrate upon insertion of the aerosol-forming article into the cavity. The device (e.g. the main body) may further comprise an electrical power supply e.g. a (rechargeable) battery for powering the heating element. It may further comprise a control unit to control the supply of power to the heating element.

In a fourth aspect, there is provided a method of using a smoking substitute system according to the third aspect, the method comprising:

inserting the article/consumable into the device; and

heating the article/consumable using the heating element.

In some embodiments, the method comprises inserting the article/consumable into a cavity within the main body and penetrating the article/consumable with the heating element upon insertion of the article/consumable. For example, the heating element may penetrate the aerosol-forming substrate in the article/consumable. The absence of a bridge portion spanning the entire transverse direction of the web that is gathered to form the aerosol-forming substrate (which, in the prior art results in a band of un-slit plant material within the substrate) means that penetration of the substrate by the heating element is facilitated.

In a fifth aspect, there is provided a method of forming a web of plant material comprising:

providing a sheet of plant material;

dividing the plant material into a plurality of longitudinally-extending shreds of plant material by forming a plurality longitudinally-extending slits,

wherein the slits are discontinuous such that the method further comprises leaving a plurality of unslit transverse bridge portions each joining at least two adjacent shreds, wherein none of the bridge portions extend across the entire transverse width of the web.

In preferred embodiments, the method comprises leaving un-slit transverse bridge portions such that adjacent transverse bridge portions are longitudinally spaced relative to one another.

In some embodiments, method comprises leaving un-slit transverse bridge portions between ten or fewer e.g. nine or fewer e.g. eight or seven or six or five or four or three or fewer immediately adjacent shreds of plant material. In preferred embodiments, the method comprises leaving un-slit transverse portions between only two adjacent shreds.

The method may comprise forming a first group of discontinuous slits and transverse bridge portions by passing the sheet of plant material through a pair of interdig itated transverse stacks of rotary cutting blades wherein a plurality of blades within the interdigitated transverse stacks each comprise a respective notch, wherein the notches are circumferentially staggered relative to one another i.e. angularly spaced in a circumferential direction relative to one another. Preferably the method comprises using a pair of interdigitated transverse stacks of rotary cutting blades wherein the notches are completely unaligned in the circumferential direction meaning that there is no overlap of the notches in the circumferential direction.

In this way, the notches in the cutting blades will form the discontinuities in the discontinuous slits and the circumferential off-setting of the notches will result in the resulting discontinuities/transverse bridge portions being off-set by a longitudinal spacing which will equal the circumferential spacing of the adjacent notches.

In some embodiments, the method comprises using a pair of interdigitated transverse stacks of rotary cutting blades wherein the notched blades are immediately adjacent one another in the interdigitated transverse stacks forming a first group of notched blades within the interdigitated transverse stacks such that the discontinuous slits are formed immediately adjacent one another.

In some embodiments, the method comprises using a pair of interdigitated transverse stacks further comprising at least one (e.g. a plurality of) un-notched blade(s) for forming continuous slits in the web of plant material. The un-notched blades may be grouped together in the interdigitated transverse stack to form a group of continuous slits in the web of plant material.

In some embodiments, the method comprises using a pair of interdigitated transverse stacks comprising a second group of notched blades immediately adjacent one another in the interdigitated transverse stack for forming a second group of discontinuous slits.

The group of un-notched blades may be interposed between the first and second group of notched blades.

In some embodiments, the method comprises using a pair of interdigitated transverse stacks wherein the plurality of notched blades are arranged within the interdigitated transverse stacks such that the angular spacing from a notch in a first blade within the interdigitated transverse stack progressively increases (e.g. by an equal amount) in a transverse direction along the stack (i.e. in the stacking direction of the blades). In this way the method comprises forming a plurality of diagonally arranged/diagonally offset discontinuities/transverse bridge portions.

In some embodiments, the method comprises using a pair of interdigitated transverse stacks wherein the plurality of notched blades are arranged within the interdigitated transverse stacks such that the angular spacing from a notch in a first blade within the interdigitated transverse stack alternately increases and decreases in a transverse direction along the stack (i.e. in the stacking direction of the blades). In this way the method comprises forming a plurality of discontinuities/transverse bridge portions which may be substantially randomly arranged or may form a plurality of longitudinally spaced diagonal arrangements which adjacent bridge portions forming part of different diagonal arrangements. In some embodiments, the method comprises using a pair of interdigitated transverse stacks wherein the transverse spacing between adjacent blades in the stacks may be substantially equal.

The transverse spacing between the blades may be equal to greater than 0.5mm. The transverse spacing between the blades may be equal to or less than 2mm, e.g. equal to or less than 1.5mm. The transverse spacing between the blades may be around 1 mm.

The circumferential length of the notches (and thus the longitudinal dimension of the transverse bridge portions) may be equal to or greater than 1 mm, e.g. equal to or greater than 2mm or 3mm. In some embodiments, the circumferential length is equal to or less than 6mm, e.g. equal to or less than 5mm. In some embodiments, the circumferential length is around 4mm.

In a sixth aspect, there is provided a method of forming an article (e.g. a HNB consumable) according to the second or third aspect comprising:

forming the web of plant material according to the method of the fifth aspect;

gathering the web of plant material to form a cylindrical rod;

cutting the cylindrical rod to form a cylindrical aerosol-forming substrate; and

circumscribing the aerosol-forming substrate using a wrapping layer.

The method may comprise forming the cylindrical rod having an axial length of around 120mm and cutting the cylindrical rod to form an aerosol-forming substrate having an axial length of around 12mm.

The skilled person will appreciate that except where mutually exclusive, a feature or parameter described in relation to any one of the above aspects may be applied to any other aspect. Furthermore, except where mutually exclusive, any feature or parameter described herein may be applied to any aspect and/or combined with any other feature or parameter described herein.

Summary of the Figures

So that the invention may be understood, and so that further aspects and features thereof may be appreciated, embodiments illustrating the principles of the invention will now be discussed in further detail with reference to the accompanying figures, in which:

Figure 1 shows a first embodiment of a web of plant material;

Figure 2 shows a second embodiment of a web of plant material;

Figure 3 shows a third embodiment of a web of plant material;

Figure 4 shows a fourth embodiment of a web of plant material; Figure 5 shows a first embodiment of an HNB consumable;

Figure 6 shows a second embodiment of an HNB consumable

Figure 7 shows a third embodiment of an HNB consumable; and

Figure 8 shows the first embodiment within a device forming an HNB system.

Detailed Description of the Figures

As shown in Figure 1 the present disclosure relates to web 1 of plant material, having a plurality of longitudinally-extending shreds 2a, 2b, 2c, 2d etc.. Each shred has a transverse width of 1 mm.

The web 1 shreds 2a, 2b, 2c, 2d etc. is/are formed of a sheet of homogenised tobacco e.g. a sheet of paper recon or slurry recon tobacco which is slit by passing it longitudinally between a pair of interdigitated transverse stacks of rotary cutting blades with the blades equally spaced apart by 1 mm. The blades cut a plurality of longitudinally-extending slits 3a, 3b, 3c, 3d etc. in the sheet thus forming the web 1.

A plurality of blades within the interdigitated transverse stacks each comprise a respective notch having a circumferential extension of 4mm and the notches are circumferentially staggered relative to one another i.e. angularly spaced in a circumferential direction relative to one another. The notches are completely unaligned in the circumferential direction meaning that there is no overlap of the notches in the circumferential direction.

As the sheet of tobacco passes longitudinally through the interdigitated stacks of rotating blades, each notch will result in a longitudinal discontinuity 4a, 4b, 4c, 4d etc. of 4mm in the slits 3a, 3b, 3c, 3d etc.. These discontinuities in the slits 3a, 3b, 3c, 3d create transverse bridge portions 5a, 5b, 5c, 5d of un-slit tobacco sheet which span two adjacent shreds. Thus each bridge portion 5a, 5b, 5c, 5d has a transverse width of 2mm and a longitudinal length of 4mm.

The discontinuities 4a, 4b, 4c, 4d transverse bridge portions 5a, 5b, 5c, 5d are off-set from one another by a longitudinal spacing which will equal the circumferential spacing of the adjacent notches on the adjacent rotary cutting blades. Thus it can be seen that there is no bridge portion extending across the entire transverse width of the web 1. Each bridge portion 5a, 5b, 5c, 5d spans only two adjacent shreds and adjacent bridge portions are completely unaligned in the transverse direction.

In the embodiments shown in Figure 1 , the discontinuous slits 3a, 3b, 3c, 3d are immediately adjacent one another and form a first group A of discontinuous slits 3a, 3b, 3c, 3d etc... The web 1 further comprises a second group A’ of discontinuous slits 3a’, 3b’, 3c’, 3d’ etc. which are transversely spaced from the first group A of discontinuous slits 3a, 3b, 3c, 3d etc. by a group B of continuous slits 6a, 6b, 6c, 6d, etc. (i.e. slit(s) without any discontinuities/transverse bridge portions). The continuous slits 6a, 6b, 6c, 6d are formed by including adjacent un-notched blades within the interdigitated transverse stack of blades.

As can be seen in Figure 1 , the longitudinal spacing between adjacent discontinuities 4a, 4b, 4c, 4d and bridge portions 5a, 5b, 5c, 5d, etc. is equal (arising from an equal angular spacing of the notches on the blades) such that the discontinuities 4a, 4b, 4c, 4d and bridge portions 5a, 5b, 5c, 5d, are diagonally off-set on the web.

The web T shown in Figure 2 is substantially the same as that shown in Figure 1 except that there are continuous slits 7a, 7b, 7c, 7d etc. interposed between adjacent discontinuous slits 3a, 3b, 3c, 3d in the first group A of discontinuous slits.

The group B of continuous slits 6a, 6b shown in Figure 2 has a smaller transverse dimension (i.e. there are fewer continuous slits) but this group B of continuous slits may be increased in size (i.e. may contain a greater number of continuous slits).

Figure 3 shows a third embodiment of a web 1” which is the same as the first embodiment except that the discontinuous slits 3a, 3b, 3c, 3d are formed by feeding the sheet longitudinally through a pair of interdigitated transverse stacks of notched blades which are arranged such that the angular spacing from a notch in a first blade within the interdigitated transverse stack alternately increases and decreases in a transverse direction along the stack (i.e. in the stacking direction of the blades). This results in a plurality of discontinuities 4a, 4b, 4c, 4d transverse bridge portions 5a, 5b, 5c, 5d arranged so as to form two longitudinally staggered diagonal arrangements within the group of group of discontinuous slits 3a, 3b, 3c, 3d.

Figure 4 shows a fourth embodiment of a web T”, which includes additional continuous slits 7a, 7b, 7c, 7d interposed between the discontinuous slits 3a, 3b, 3c, 3d. Like the embodiment shown in Figure 3, the web T” is formed by feeding the sheet longitudinally through a pair of interdigitated transverse stacks of notched blades which are arranged such that the angular spacing from a notch in a first blade within the interdigitated transverse stack alternately increases and decreases in a transverse direction along the stack (i.e. in the stacking direction of the blades). However, in this embodiment of the web T” the resulting bridge portions are randomly arranged within the group of discontinuous slits 3a, 3b, 3c, 3d.

Any of the webs shown in the Figures may be being gathered in a transverse direction to form a cylindrical rod of tobacco shreds haying a diameter of around 7mm. The tobacco rod may be cut to the desired length (e.g. 12mm) and at least partially circumscribed by a wrapping layer to form a heat-not-burn (HNB) consumable.

As shown in Figure 5, the HNB consumable 1 comprises an aerosol-forming substrate 2 at the upstream end of the consumable 1.

The aerosol-forming substrate 2 comprises 65 wt% tobacco which is provided in the form of gathered shreds produced from a web of slurry/paper recon tobacco as described above. The tobacco is dosed with 20wt% of a humectant such as propylene glycol (PG) or vegetable glycerine (VG) and has a moisture content of between 7-9 wt%. The aerosol-forming substrate further comprises cellulose pulp filler and guar gum binder.

The aerosol-forming substrate 2 is formed in a substantially cylindrical shape such that the consumable resembles a conventional cigarette. It has diameter of around 7mm and an axial length of around 12 mm.

The aerosol-forming substrate 2 is circumscribed by a paper wrapping layer 3.

The consumable 1 comprises an upstream filter element 4 and a downstream (terminal) filter element 5. The two filter elements 4, 5 and spaced by a cardboard tube spacer 6. Both filter elements 4, 5 are formed of cellulose acetate tow and wrapped with a respective paper plug layer (not shown).

Both filter elements have a substantially cylindrical shape. The diameter of the upstream filter 4 matches the diameter of the aerosol-forming substrate 2. The diameter of the terminal filter element 5 is slightly larger and matches the combined diameter of the aerosol-forming substrate 2 and the wrapping layer 3. The upstream filter element is slightly shorter in axial length than the terminal filter element at an axial length of 10mm compared to 12mm for the terminal filter element.

The cardboard tube spacer is longer than each of the two filter portions having an axial length of around 14mm.

Each filter element 4, 5 is a hollow bore filter element with a hollow, longitudinally extending bore. The diameter of the bore in the upstream filter is slightly larger than the diameter of the bore in the terminal filter having a diameter of 3mm compared to 2 mm for the terminal filter element.

The cardboard tube spacer 6 and the upstream filter portion 4 are circumscribed by the wrapping layer 3.

The terminal filter element 5 is joined to the upstream elements forming the consumable by a circumscribing paper tipping layer 7. The tipping layer 7 encircles the terminal filter portion and has an axial length of around 20mm such that it overlays a portion of the cardboard tube spacer 6. Figure 6 shows a second embodiment of a consumable T which is the same as that shown in Figure 1 except that the terminal filter element 5 is a solid filter element and comprises a crushable capsule 8 (crush- ball) having a shell wall containing a liquid menthol or cherry or vanilla flavourant. The capsule 8 is spherical and has a diameter of 3.5mm. It is positioned within the axial centre of the terminal filter portion 5.

Figure 7 shows a third embodiment of a consumable 1” which is the same as the first embodiment except that the wrapping layer 3 does not completely circumscribe the cardboard tube spacer 6 such that there is an annular gap 9 between the tipping layer 7 and the cardboard tube spacer 6 downstream of the end of the wrapping layer 3.

Figure 8 shows the first embodiment inserted into an HNB device 10 comprising a rod-shaped heating element 20. The heating element 20 projects into a cavity 1 1 within the main body 12 of the device.

The consumable 1 is inserted into the cavity 1 1 of the main body 12 of the device 10 such that the heating rod 20 penetrates the aerosol-forming substrate 2. Heating of the reconstituted tobacco in the aerosolforming substrate 2 is effected by powering the heating element (e.g. with a rechargeable battery (not shown)). As the tobacco is heated, moisture and volatile compound (e.g. nicotine) within the tobacco and the humectant are released as a vapour and entrained within an airflow generated by inhalation by the user at the terminal filter portion 5.

As the vapour cools within the upstream filter element 4 and the cardboard tube spacer 6, it condenses to form an aerosol containing the volatile compounds for inhalation by the user.

The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the scope of the invention.

For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader. The inventors do not wish to be bound by any of these theoretical explanations. Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

Throughout this specification, including the claims which follow, unless the context requires otherwise, the words“have”,“comprise”, and“include”, and variations such as“having”,“comprises”,“comprising”, and “including” will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

It must be noted that, as used in the specification and the appended claims, the singular forms“a,”“an,” and“the” include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from“about” one particular value, and/or to“about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent“about,” it will be understood that the particular value forms another embodiment. The term“about” in relation to a numerical value is optional and means, for example, +/- 10%.

The words "preferred" and "preferably" are used herein refer to embodiments of the invention that may provide certain benefits under some circumstances. It is to be appreciated, however, that other embodiments may also be preferred under the same or different circumstances. The recitation of one or more preferred embodiments therefore does not mean or imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the disclosure, or from the scope of the claims.