Patent Description:
From, for example <CIT>, it is known to provide aerosol-forming gel in a sealed capsule, which capsule is inserted into a heating chamber of an aerosol-forming system.

Also aerosol-generating articles comprising several segments arranged in an end-to-end position are known. One of the segments may be a segment comprising an aerosol-forming substrate and a susceptor for heating the aerosol-forming substrate.

It is desirable to provide an aerosol-generating rod segment to be used in an aerosol-generating article that is inductively heatable and wherein the rod segment comprises an aerosol-forming substrate in the form of a gel.

According to the invention there is provided an aerosol-generating rod segment comprising a rod-shaped susceptor casing and an aerosol-forming gel contained in the rod-shaped susceptor casing. The susceptor casing comprises a bottom, a side wall and an opening arranged opposite the bottom. The aerosol-forming gel is retained inside the susceptor casing in axial direction of the aerosol-generating rod segment by at least one positive locking means.

Aerosol-forming substrate in the form of gel has the advantage that a substrate may be provided basically having any shape. However, as gel as such is air-tight, any vaporized gel may cause pressure on the remaining gel that is not or not yet vaporized. If, for example, a gel plug is heated at one end of the plug, the entire plug may be forced out of its position. However, the provision of aerosol-forming substrate in the form of gel in a casing has several advantages. The gel may be filled into the casing, for example in a liquid form and may thus come in intimate contact with the casing. By this, heat transfer from the casing to the aerosol-forming gel is very direct and optimized. Casings additionally made of a susceptor material may directly be heated via induction heating in a power saving manner and such that no extra material or space is needed for electrical wires or resistive heaters.

A casing is generally as open as possible in order to use as little material as possible, in particular since aerosol-generating articles comprising rod-shaped aerosol-generating segments are articles that are typically disposed of after use. Yet further, a casing needs to be open for filling the casing or at least for vaporized gel to leave the casing. Positive locking means provided in or at the casing acting in axial direction on the aerosol-forming gel allow to retain the aerosol-forming gel in the casing. For example, when a casing is heated at the bottom of the casing gel is vaporized at the bottom end of the casing. The generated vapour now tends to push the remaining non-vaporized gel in axial direction out of the casing through the opening of the casing arranged opposite the bottom. Positive locking means provided in the casing may hold this non-vaporized gel in the casing.

The positive locking means may be arranged at various positions on or in the casing and may also be designed in various shapes in order to fulfil the retaining action in axial direction of the aerosol-generating rod segment.

At least one of said at least one positive locking means is designed as an inwardly directed seam of the susceptor casing. In particular, the at least one positive locking means may form an inwardly arranged flange of the casing. The seam is arranged adjacent to an end section of the susceptor casing, which end section is arranged opposite the bottom of the susceptor casing.

A positive locking means in the form of a seam is formed by an inwardly bent end portion of the side wall of the susceptor casing. Inwardly bent end portions of the side wall are advantageous from a manufacturing point of view as no extra seam or flange needs to be attached to the casing. In addition, no unintentional leak may be present between a casing and a separately attached seam. Yet further, the casing may, for example, be formed, filled with gel and then partly closed by simply bending end portions of the casing walls radially inwardly.

Preferably, at least one of said at least one positive locking means is designed as a radially inwardly directing protrusion. The radially inwardly directing protrusion has a radial extension in circumferential direction of the susceptor casing, which radial extension is larger than a longitudinal extension of the protrusion in longitudinal direction of the susceptor casing. A radially inwardly directing protrusion preferably forms one or several ribs arranged circumferentially along the interior of the sidewall of the casing.

A radially inwardly directing protrusion may be formed, for example, by a thicker side wall at the position of the protrusion. The radially inwardly directing protrusion may be formed, for example, by a locally deformed casing.

Preferably, a radially inwardly directing protrusion is a radially inwardly directing deformation of the side wall of the susceptor casing. Deformations of the side wall may be present in the casing before filling the casing or may be created after the casing has been filled, for example together with an inwardly directing seam at the opening end of the casing.

A protrusion may be arranged at any position along the length of the casing. Preferably, the protrusion is arranged between half of the height of the casing and the opening of the casing. Preferably, a radially inwardly directing protrusion is arranged in an intermediate section of the side wall of the susceptor casing.

An intermediate section may basically extend between the two extreme ends of the casing, thus between the bottom and the opening end of the casing. The intermediate section preferably extends over about <NUM> percent and about <NUM> percent of the length of the casing, more preferably between about <NUM> percent and about <NUM> percent, for example between about <NUM> percent and about <NUM> percent of the length of the casing.

The positive locking means preferably comprise several protrusions. The several protrusions may, for example, be arranged at a distance to each other along the length of the casing. The several protrusions may, for example, be arranged at different circumferential positions. In addition or alternatively, the several protrusions may, for example, be arranged opposite each other at a same longitudinal length position of the casing.

The at least one positive locking means may be provided in one, two, three, four or in a plurality of sectors of the susceptor casing. The at least one positive locking means may, for example, be a continuous protrusion such as a continuous rib arranged along the circumference of the susceptor casing. The at least one positive locking means may, for example, be a discontinuous protrusion such as a discontinuous rib arranged along the circumference of the susceptor casing.

The at least one positive locking means is preferably provided in a circumferential range of each sector of at least <NUM> degree, <NUM> degree, <NUM> degree, <NUM> degree, <NUM> degree, <NUM> degree, <NUM> degree or up to <NUM> degree, <NUM> degree, <NUM> degree, <NUM> degree, <NUM> degree, <NUM> degree, <NUM> degree, <NUM> degree, <NUM> degree or <NUM> degree.

Preferably, at least one of the at least one positive locking means is arranged along an entire circumference of the susceptor casing, in particular along an entire circumference of the side wall of the susceptor casing.

At least one positive locking means may be provided along an entire length of the casing, for example sequentially or continuously. For example, the at least one positive locking means may be formed by parts of the side walls or by entire side walls that are continuously converging radially inward from a bottom of the casing to the opening of the casing. The casing may, for example, form a truncated hollow cone. The casing may, for example, have a folded side wall structure, where some of the folds or corrugations continuously converge radially inward. The converging side walls form a positive locking means constructed to act along the entire length of the casing as a retention for the aerosol-forming gel in longitudinal direction of the casing. Preferably, corrugations converge radially inwardly toward the opening of the susceptor casing. Preferably, some corrugations, for example a third, half or all corrugations, converge radially inwardly toward the opening of the susceptor casing.

The aerosol-forming gel may be retained in the cartridge by the at least one positive locking means with clearance in the longitudinal direction of the susceptor casing. Clearance may, for example, be present when the casing is not entirely filled with aerosol-forming gel. A clearance then extends between a filling level of the gel and the positive locking means. A filling level may, for example, be at about half or three-quarter of the length of the casing, while the positive locking means is provided at the opening end of the casing.

The aerosol-forming gel may be fixed in its position in the susceptor casing by the at least one positive locking means. Thus, the aerosol-forming gel may be fixed in its position without clearance. For example, a casing may entirely be filled with aerosol-forming gel. Alternatively, the aerosol-forming gel may be fixed in its position by positive locking means arranged along the length of the casing. Thus, positive locking means may be provided in an intermediate section of the casing between the bottom of the casing and a filling level of the gel. For example, the gel may be filled to a filling level corresponding to about three-quarter of the casing, while positive locking means may be arranged between the bottom of the casing and three-quarter of the casing, preferably at about half of the length of the casing.

The side wall of the susceptor casing may be made of susceptor material. The bottom of the susceptor casing may be made of susceptor material. Preferably, at least part of the bottom and part of the side wall of the casing are made of susceptor material. More preferably, the entire bottom and the entire side wall of the casing are made of susceptor material.

The bottom of the susceptor casing may be open or may be closed. For example, the bottom may comprise one or several openings, for example, for an airflow to pass through the bottom opening into the casing.

Preferably, the bottom of the susceptor casing is closed.

The side wall of the susceptor casing is corrugated. Preferably, corrugations are aligned in a longitudinal direction of the susceptor casing. Corrugations enlarge the overall size of the surface of the susceptor and by this a contact surface between the aerosol-forming gel and the susceptor material.

Preferably, the side wall of the susceptor casing has the form of a cylinder. The cylinder may have a circular or non-circular cross section.

The bottom and the side wall of the susceptor casing may comprise a same thickness or a same material. The bottom and the side wall of the susceptor casing may comprise a same thickness and a same material. Preferably, the bottom and side wall of the susceptor casing are made of a same susceptor material.

Preferably, the bottom of the susceptor casing and the side wall of the susceptor casing are made as a single piece. For example, bottom and side wall are folded from the same sheet of susceptor material.

The bottom may have a circular cross-section or may, for example, be a polygon.

The bottom and the side wall of the susceptor casing may comprise a different thickness or a different material. The bottom and the side wall of the susceptor casing may comprise a different thickness and a different material.

The susceptor casing or parts of the casing may be made of any susceptor material suitable for forming a rod-shaped casing containing aerosol-forming gel, wherein the casing containing the gel is part of or forms an aerosol-generating rod segment. Preferably, the susceptor casing comprises or is made of aluminium or stainless steel.

Preferably, the susceptor casing is formed from a sheet of susceptor material having a thickness between <NUM> micrometer and <NUM> micrometer, preferably between <NUM> micrometer and <NUM> micrometer.

Preferably, the aerosol-forming gel is a gel plug. The gel plug may be formed before being inserted into the casing. The gel plug may be formed in the casing, for example, by filling liquid aerosol-forming gel into the casing and subsequently solidifying the gel. The gel plug may be inserted into the casing before forming the at least one positive locking means.

The aerosol-forming gel may have a filling height of at least <NUM> percent, <NUM> percent, <NUM> percent, <NUM> percent, <NUM> percent, <NUM> percent or at most <NUM> percent, <NUM> percent, <NUM> percent, <NUM> percent, <NUM> percent, <NUM> percent, <NUM> percent, <NUM> percent, <NUM> percent, <NUM> percent, <NUM> percent, <NUM> percent of the susceptor casing.

Preferably, the aerosol-forming gel is entirely contained inside the susceptor casing.

Preferably, the aerosol-forming gel comprises a solidifiable material.

Preferably, the aerosol-forming gel comprises a thermoreversible material.

The aerosol-forming gel may comprise a gelling agent. Preferably, the aerosol-forming gel comprises between <NUM> percent and <NUM> percent by weight of a gelling agent, for example between <NUM> percent and <NUM> percent by weight or between <NUM> percent and <NUM> percent by weight of a gelling agent.

The aerosol-generating rod segment may be substantially cylindrical in shape. The aerosol-forming rod segment is substantially elongate. The aerosol-forming rod segment also has a length and a circumference substantially perpendicular to the length.

The aerosol-generating rod segment has a diameter that is approximately equal to a diameter of the aerosol-generating article. Preferably, the aerosol-generating rod segment has a diameter between <NUM> millimeter and <NUM> millimeter. It is preferable that the diameter of the aerosol-generating rod segment is greater than <NUM>, for example between <NUM> and <NUM>. The aerosol-generating rod segment has a length that may be defined as the dimension along the longitudinal axis of the aerosol-generating article. The length of the aerosol-generating rod segment may be between <NUM> millimeter and <NUM> millimeter, for example between <NUM> and <NUM> or between <NUM> and <NUM>, for example <NUM> millimeter. It is preferred that the aerosol-generating rod segment is substantially cylindrical.

The invention also refers to an aerosol-generating article, in particular an inductively heatable aerosol-generating article, comprising a plurality of segments arranged in an end-to-end position and wrapped in a wrapper to form a rod. The plurality of segments comprises an aerosol-generating rod segment as described in the present application.

The plurality of segments may comprise one or more hollow tubes, a spacer element, an airflow directing element, an empty cavity, a second susceptor containing element, an aerosol-cooling element and a filter segment.

Preferably, the plurality of segments comprises at least one of a hollow tube, a filter segment, an airflow directing element and an empty cavity.

The aerosol-generating article may comprise a mouthpiece element. The mouthpiece element may be located at the mouth end or downstream end of the aerosol-generating article.

The mouthpiece element may comprise at least one filter segment. The filter segment may be a cellulose acetate filter plug made of cellulose acetate tow. The filter segment is <NUM> millimeter in length in one embodiment, but may have a length of between <NUM> millimeter and <NUM> millimeter.

The aerosol-generating article may comprise a support element that may be located immediately downstream of the aerosol-generating rod segment and may abut the aerosol-generating rod segment.

The support element may be formed from any suitable material or combination of materials. For example, the support element may be formed from one or more materials selected from the group consisting of: cellulose acetate; cardboard; crimped paper, such as crimped heat resistant paper or crimped parchment paper; and polymeric materials, such as low density polyethylene (LDPE). In a preferred embodiment, the support element is formed from cellulose acetate.

The support element may comprise a hollow tubular element. In a preferred embodiment, the support element comprises a hollow cellulose acetate tube.

The support element preferably has an external diameter that is approximately equal to the external diameter of the aerosol-generating article.

The support element may have an external diameter of between <NUM> millimeter and <NUM> millimeter, for example of between <NUM> and <NUM> or of between <NUM> and <NUM>. In a preferred embodiment, the support element has an external diameter of <NUM> plus or minus <NUM> percent. The support element may have a length of between <NUM> millimeter and <NUM> millimeter. In a preferred embodiment, the support element has a length of <NUM>. The support element may have a wall thickness between <NUM> and <NUM>, preferably between <NUM> and <NUM>.

The aerosol-generating article may comprise a thin support element. The thin support element may have an external diameter of between <NUM> millimeter and <NUM> millimeter, for example of between <NUM> and <NUM> or of between <NUM> and <NUM>. In a preferred embodiment, the thin support element has an external diameter of <NUM> plus or minus <NUM> percent. The thin support element may have a length of between <NUM> millimeter and <NUM> millimeter. In a preferred embodiment, the thin support element has a length of <NUM>. The thin support element may have a wall thickness between <NUM> and <NUM>, preferably between <NUM> and <NUM>.

The aerosol-generating article may comprise an aerosol-cooling element. The aerosol-cooling element may be located downstream of the aerosol-generating rod segment, for example an aerosol-cooling element may be located immediately downstream of a support element, and may abut the support element.

The aerosol-cooling element may be located between the support element and a mouthpiece element located at the extreme downstream end of the aerosol-generating article.

As used herein, the term 'aerosol-cooling element' is used to describe an element having a large surface area and a low resistance to draw. In use, an aerosol formed by volatile compounds released from the aerosol-forming substrate is drawn through the aerosol-cooling element before being transported to the mouth end of the aerosol-generating article. In contrast to high resistance-to-draw filters, for example filters formed from bundles of fibers, aerosol-cooling elements have a low resistance to draw. Chambers and cavities within an aerosol-generating article such as expansion chambers and support elements are also not considered to be aerosol cooling elements.

An aerosol-cooling element preferably has a porosity in a longitudinal direction of greater than <NUM> percent. The airflow path through the aerosol-cooling element is preferably relatively uninhibited. An aerosol-cooling element may be a gathered sheet or a crimped and gathered sheet. An aerosol-cooling element may comprise a sheet material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polyethylene terephthalate (PET), polylactic acid (PLA), cellulose acetate (CA), and aluminium foil or any combination thereof.

In a preferred embodiment, the aerosol-cooling element comprises a gathered sheet of biodegradable material. For example, a gathered sheet of non-porous paper or a gathered sheet of biodegradable polymeric material, such as polylactic acid or a grade of Mater-Bi<®> (a commercially available family of starch based copolyesters).

An aerosol-cooling element preferably comprises a sheet of PLA, more preferably a crimped, gathered sheet of PLA. An aerosol-cooling element may be formed from a sheet having a thickness of between <NUM> micrometer and <NUM> micrometer, for example <NUM> micrometer. An aerosol-cooling element may be formed from a gathered sheet having a width of between <NUM> millimeter and <NUM> millimeter. An aerosol-cooling element may have a specific surface area of between <NUM> millimeter<NUM> per millimeter length and <NUM> millimeter<NUM> per millimeter length between <NUM> millimeter<NUM> per mg weight and <NUM> millimeter<NUM> per mg weight. In some embodiments, the aerosol-cooling element may be formed from a gathered sheet of material having a specific surface area of about <NUM> millimeter<NUM> per mg weight. An aerosol-cooling element may have an external diameter of between <NUM> millimeter and <NUM> millimeter, for example <NUM>.

In some preferred embodiments, the length of the aerosol-cooling element is between <NUM> millimeter and <NUM> millimeter. Preferably, the length of the aerosol-cooling element is between <NUM> millimeter and <NUM> millimeter, for example <NUM> millimeter.

In alternative embodiments, the length of the aerosol-cooling element is between <NUM> millimeter and <NUM> millimeter. Preferably, the length of the aerosol-cooling element is between <NUM> millimeter and <NUM> millimeter, for example <NUM> millimeter.

Preferably, the aerosol-generating rod segment is arranged between a hollow acetate tube and a filter segment.

The aerosol-generating article may be substantially cylindrical in shape. The aerosol-generating article may be substantially elongate. The aerosol-generating article may have a length and a circumference substantially perpendicular to the length.

The aerosol-generating article may have a total length between <NUM> millimeter and <NUM> millimeter. In preferred embodiments, the aerosol-generating article has a total length of between <NUM> and <NUM>, for example <NUM>-<NUM>.

The aerosol-generating article may have an external diameter between <NUM> millimeter and <NUM> millimeter, for example of between <NUM> and <NUM>. In a preferred embodiment, the aerosol-generating article has an external diameter of <NUM> plus or minus <NUM> percent.

Also disclosed is a method of manufacturing an aerosol-generating rod segment. The method comprises:
providing a rod-shaped susceptor casing comprising a bottom, a side wall and an opening opposite the bottom, filling aerosol-forming gel into the susceptor casing, providing at least one form locking means in the aerosol-generating rod segment, the at least one form locking means retaining the aerosol-forming gel inside the susceptor casing.

The at least one form locking means may be provided before or after the aerosol-forming gel has been filled into the susceptor casing. Preferably, the method comprises providing the at least one form locking means in the aerosol-generating rod segment after filling the susceptor casing with the aerosol-forming gel.

The form locking means may have different forms and positions as has been described with reference to the aerosol-generating rod segment. Preferably, the method comprises forming at least one form locking means by radially inwardly bending at least parts of the side wall of the susceptor casing. These parts may be end parts of the side wall or intermediate parts. Accordingly, the form locking means may be arranged at the opening of the casing or at one or several positions along the length of the casing.

Inwardly bending parts of the side walls are very simple means to manufacture positive form locking means for retaining the aerosol-forming gel in axial direction in the casing.

Depending on a filling method and consistency of the aerosol-forming gel, the forming of the positive locking may be chosen to be performed before or after filling the casing.

Preferably, the aerosol-forming gel is solidified after filling the aerosol-forming gel into the susceptor casing.

Preferably, the method comprises inwardly bending an end portion of the side wall, thereby defining a size of the opening of the susceptor casing. Such positive locking means are particularly advantageous as the locking means directly partially close the casing. Such positive locking means are advantageous as they are independent on a filling height of the gel in the casing. In addition, a size of the positive locking means may be varied by varying the length of the end portion that is bent inwardly.

The method may comprise providing corrugations in the side wall of the susceptor casing. By the provision of corrugations a surface of the susceptor casing and also a contact surface between susceptor and aerosol-forming gel may be enhanced by a same circumferential size of the casing and of the aerosol-generating rod segment.

Preferably, the corrugations extend from the bottom to the opening of the susceptor casing, thus along an entire length of the side wall of the susceptor casing.

The method may comprise forming at least one form locking means by forming radially inwardly directing protrusions in the side wall of the susceptor casing.

Preferably, the aerosol-generating rod segment manufactured according to the method is an aerosol-generating rod segment according to the invention and as described herein.

As used herein, the term 'susceptor' refers to a material that can convert electromagnetic energy into heat. When located within a fluctuating electromagnetic field, typically eddy currents are induced and hysteresis losses occur in the susceptor causing heating of the susceptor. As the susceptor material is in direct physical and thermal contact with the aerosol-forming gel and the aerosol-forming gel is heated by the susceptor material.

The susceptor may be formed from any material that can be inductively heated to a temperature sufficient to generate an aerosol from the solid aerosol-forming substrate and the aerosol-forming liquid. Preferred susceptors comprise a metal or carbon. A preferred susceptor may comprise or consist of a ferromagnetic material, for example a ferromagnetic alloy, ferritic iron, or a ferromagnetic steel or stainless steel. A suitable susceptor may be, or comprise, aluminium. Preferred susceptors may be formed from <NUM> or <NUM> series stainless steels, for example grade <NUM>, or grade <NUM>, or grade <NUM> stainless steel. Different materials will dissipate different amounts of energy when positioned within electromagnetic fields having similar values of frequency and field strength. Thus, parameters of the susceptor such as material type, length, and thickness may all be altered to provide a desired power dissipation within a known electromagnetic field.

Preferred susceptors may be heated to a temperature in excess of <NUM> degrees Celsius.

The 'aerosol-forming gel' is herein understood to be a material or mixture of materials capable of releasing volatile compounds into an air stream passing through an article the susceptor is arranged in, preferably when the gel is heated. The provision of a gel may be advantageous for storage and transport, or during use, as the risk of leakage from the susceptor, aerosol generating article or aerosol generating device, may be reduced.

Advantageously the gel is solid at room temperature. 'Solid' in this context means that the gel has a stable size and shape and does not flow. Room temperature in this context means <NUM> degrees Celsius.

The gel may comprise an aerosol-former. Ideally the aerosol-former is substantially resistant to thermal degradation at the operating temperature of the susceptor. Suitable aerosol-formers are well known in the art and include, but are not limited to: polyhydric alcohols, such as triethylene glycol, <NUM>, <NUM>-butanediol and glycerine; esters of polyhydric alcohols, such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids, such as dimethyl dodecanedioate and dimethyl tetradecanedioate. Polyhydric alcohols or mixtures thereof, may be one or more of triethylene glycol, <NUM>, <NUM>-butanediol and, glycerine or polyethylene glycol.

Advantageously, the gel, for example, comprises a thermoreversible gel. This means that the gel will become fluid when heated to a melting temperature and will set into a gel again at a gelation temperature. The gelation temperature may be at or above room temperature and atmospheric pressure. Atmospheric pressure means a pressure of <NUM> atmosphere. The melting temperature may be higher than the gelation temperature. The melting temperature of the gel may be above <NUM> degrees Celsius, or <NUM> degrees Celsius or <NUM> degrees Celsius and may be above <NUM> degrees Celsius. The melting temperature in this context means the temperature at which the gel is no longer solid and begins to flow.

Alternatively, in specific embodiments, the gel is a non-melting gel that does not melt during use of the susceptor. In these embodiments, the gel may release the active agent at least partially at a temperature that is at or above the operation temperature of the susceptor in use, but below the melting temperature of the gel.

Preferably, the gel has a viscosity of <NUM>,<NUM> to <NUM> Pascal per second, preferably <NUM>,<NUM> to <NUM>,<NUM> Pascal per second to give the desired viscosity.

In combination with specific embodiments the gel comprises a gelling agent. In specific embodiments the gel comprises agar or agarose or sodium alginate or Gellan gum, or a mixture thereof.

In specific embodiments the gel comprises water, for example, the gel is a hydrogel. Alternatively, in specific embodiments the gel is non-aqueous.

Preferably the gel comprises an active agent. In combination with specific embodiments the active agent comprises nicotine (for example, in a powdered form or in a liquid form) or a tobacco product or another target compound for, for example, release in an aerosol. In specific embodiments the nicotine is included in the gel with an aerosol-former. Locking the nicotine into a gel at room temperature is desirable to prevent leakage of the nicotine from an aerosol-generating article.

In specific embodiments the gel comprises a solid tobacco material that releases flavour compounds when heated. Depending on the specific embodiments the solid tobacco material is, for example, one or more of: powder, granules, pellets, shreds, spaghettis, strips or sheets containing one or more of: plant material, such as herb leaf, tobacco leaf, fragments of tobacco ribs, reconstituted tobacco, homogenised tobacco, extruded tobacco and expanded tobacco.

There are embodiments where the gel comprises other flavours, for example menthol. Menthol can be added either in water or in the aerosol former prior to the formation of the gel.

In embodiments where agar is used as the gelling agent, the gel may comprise between <NUM> and <NUM> percent by weight, preferably between <NUM> and <NUM> percent by weight, agar. Preferably the gel further comprises between <NUM> and <NUM> percent by weight nicotine. Preferably, the gel further comprises between <NUM> percent and <NUM> percent by weight (or between <NUM> and <NUM> percent by weight) glycerine. In specific embodiments a remainder of the gel comprises water and flavourings.

Preferably the gelling agent is agar, which has the property of melting at temperatures above <NUM> degrees Celsius and turning back to gel at around <NUM> degrees Celsius. This property makes it suitable for hot environments. The gel will not melt at <NUM> degrees Celsius, which is useful if the system is left in a hot automobile in the sun, for example. A phase transition to liquid at around <NUM> degrees Celsius means that the gel only needs to be heated to a relatively low-temperature to induce aerosolization, allowing low energy consumption. It may be beneficial to use only agarose, which is one of the components of agar, instead of agar.

When Gellan gum is used as the gelling agent, typically the gel comprises between <NUM> and <NUM> percent by weight Gellan gum. Preferably the gel further comprises between <NUM> and <NUM> percent by weight nicotine. Preferably, the gel comprises between <NUM> percent and <NUM> percent by weight glycerin. In specific embodiments a remainder of the gel comprises water and flavourings.

In one example, the gel comprises <NUM> percent by weight nicotine, <NUM> percent by weight glycerol, <NUM> percent by weight water and <NUM> percent by weight agar.

In another example, the gel comprises <NUM> percent by weight glycerol, <NUM> percent by weight water, <NUM> percent by weight tobacco and <NUM> percent by weight agar.

There is also provided a method for assembling a rod-shaped aerosol-generating article comprising a cup-shaped susceptor. The cup-shaped susceptor may be a cup-shaped susceptor casing according to the invention and as described in the application.

The method comprises positioning a hollow tube in a vertical manner, providing a cup-shaped susceptor in the hollow tube, filling an aerosol-forming gel into the cup-shaped susceptor, and inserting an endpiece into the hollow tube.

A hollow tube may be positioned around a susceptor or a cup-shaped susceptor may be inserted into a hollow tube. Preferably, the cup-shaped susceptor is inserted in the hollow tube.

Preferably, the method comprises inserting the susceptor through a top end of the hollow tube and positioning the susceptor at a bottom end of the hollow tube. The cup-shaped susceptor may be arranged substantially flush with the bottom end of the hollow tube.

A cup-shaped susceptor may be filled with aerosol-forming gel before the susceptor is positioned in the hollow tube. The susceptor may be filled with gel after the susceptor has been positioned in the hollow tube. Preferably, the method comprises filling the cup-shaped susceptor with aerosol-forming gel after positioning the susceptor in the hollow tube.

The method may comprise inserting a gel dosing device in the hollow tube, dosing a desired amount of aerosol-forming gel into the susceptor and retreating the gel dosing device from the hollow tube. The gel may be in a liquid or paste form when being filled into the susceptor.

The endpiece may be inserted into the hollow tube through the top end of the hollow tube and close the hollow tube. The endpiece may be arranged flush with the top end of the hollow tube. The endpiece may form a recessed end of the hollow tube to form an aerosol-generating article with recessed filter end. The endpiece may extend from the hollow tube forming an extended filter portion of the article.

Preferably, a length of an aerosol-generating article is defined by the length of the hollow tube.

Preferably, the endpiece is a preassembled combination of segments. The endpiece may comprise, for example, one or more filter elements, one or more hollow tubes such as cellulose acetate tubes or a diffuser segment.

Preferably, the endpiece comprises at least one of a filter, a hollow tube and a diffuser element.

The hollow tube may be a cardboard tube or a plastics tube. Preferably, the hollow tube is a cardboard tube. Preferably, the hollow tube is a spirally-wound cardboard tube.

The hollow tube may have a diameter between <NUM> millimeter and <NUM> millimeter. Preferably, the diameter of the hollow tube is greater than <NUM>, for example between <NUM> and <NUM>.

The hollow tube may have a total length between <NUM> millimeter and <NUM> millimeter. In preferred embodiments, the hollow tube has a total length of between <NUM> and <NUM>, for example <NUM> to <NUM>. It is preferred that the hollow tube is substantially cylindrical.

A wall thickness of the hollow tube may be between <NUM> millimeter and <NUM> millimeter, preferably between <NUM> and <NUM>.

The method may further comprise pre-forming the cup-shaped susceptor from a piece of susceptor sheet material. Preferably, the cup-shaped susceptor is formed from a disc-shaped piece of susceptor sheet material. The disc may, for example, be cut-out from a sheet of aluminum foil or stainless steel foil.

The cup-shaped susceptor may have side walls that are even. The side walls of the cup-shaped susceptor may be corrugated. Preferably, corrugations are aligned in a longitudinal direction of the cup-shaped susceptor. The corrugations may be fluted or have a zig-zag pattern when seen along a cross section of the side wall, such as to form a cupcake-shaped susceptor.

Preferably, the side walls of the cup-shaped susceptor exert a retaining force onto the hollow tube when the cup-shaped susceptor is inserted and positioned in the hollow tube.

The side walls of a cup-shaped susceptor extend radially outward before being pushed radially inward to achieve a substantially cylindrical form, preferably corresponding to the internal diameter of the hollow tube. The corrugations allow a well-defined folding of the side walls of the susceptor when the susceptor is inserted in the hollow tube. In addition, the side walls may exert a retaining force between the susceptor and the hollow tube. This retaining force may support a positioning of the cup-shaped susceptor in the hollow tube and may prevent a cup-shaped susceptor from being displaced in the hollow tube once the cup-shaped susceptor has been positioned in the hollow tube.

To generate a retaining force, the diameter of the cup-shaped susceptor is larger than the inner diameter of the hollow tube, before the susceptor is positioned in the hollow tube. Preferably, the diameter of the cup-shaped susceptor is larger than the inner diameter of the hollow tube by at least <NUM> percent. Preferably, the diameter of the cup-shaped susceptor is larger than the inner diameter of the hollow tube by at least <NUM> millimeter. Upon positioning the cup-shaped susceptor, the side walls are compressed radially inwardly.

The cup-shaped susceptor may have a larger diameter over an entire length of the susceptor. The cup-shaped susceptor may have a larger diameter over a part of the length of the susceptor. Preferably, the cup-shaped susceptor has a larger diameter in an opening portion of the cup-shaped susceptor.

Preferably, the side walls of the cup-shaped susceptor have a certain elasticity and flexibility. The elasticity and flexibility allows to press the susceptor side walls radially inwardly without damaging or breaking the susceptor material. The elasticity and flexibility also causes the side walls to push radially outward and generate a retaining force when positioned in the hollow tube.

The cup-shaped susceptor may comprise an opening having a same diameter or a larger diameter than the bottom of the cup-shaped susceptor. The cup-shaped susceptor may have an opening having a diameter smaller than the diameter of the bottom. The cup-shaped susceptor may comprise positive locking means, for example arranged at the opening portion of the cup-shaped susceptor. For example, the cup-shaped susceptor may comprise an inwardly directing rim arranged around the opening of the cup-shaped susceptor.

Manufacturing of inductively heatable susceptor casings provided with an inwardly directing rim to retain an aerosol-forming gel inside the casing may, for example, be realized by embossing or folding. However, the small dimensions of the susceptor casing and its use in disposable aerosol-generating articles are demanding aspects in the manufacture of such casings. It is therefore desirable to have a manufacturing process for such casings, which is inexpensive, which uses little material and which allows mass production.

There is provided a method for forming a top-rim bended rod-shaped susceptor casing. The method may in particular be used for forming a rod-shaped susceptor casing to be filled with aerosol-forming gel to form an aerosol-generating rod segment according to the invention and as described herein.

The method comprises loading a forming tool with a disc of a susceptor sheet material such as an aluminium disc, deep drawing the disc to form a semi-finished casing, widen the side walls of the semi-finished casing, and inwardly bending a rim at the opening of the casing. Thereby, a rod-shaped susceptor casing is formed, which may be removed and further processed, such as being filled with an aerosol-forming gel and subsequently being introduced into an aerosol-generating article.

The deep drawing of the disc of susceptor sheet material is preferably performed by insertion of a plunger into a mold. Thereby the disc is deep drawn in the mold.

Preferably, the widening of the side walls of the semi-finished casing are performed by rotating the plunger along the sides of the mold, thereby pressing the side walls of the semi-finished casing against the walls of the mold.

The rim forming may generally be achieved by pressing the casing from below against an upper forming tool to bend the uppermost end portion of the side walls of the casing radially inwards.

In <FIG> examples of susceptor casings are shown that are not yet provided with positive locking means.

In <FIG> a perspective side view of a cup-shaped casing <NUM> is shown. The casing has a bottom <NUM> and a side wall <NUM> extending from the bottom <NUM>. The casing <NUM> has an opening <NUM> arranged opposite the bottom <NUM>. The casing has the form of an open cylinder with a circular cross section, which cross section is substantially constant over the entire length of the casing. The casing <NUM> is partly or preferably entirely made of a susceptor material, for example stainless steel. The casing <NUM> is filled partly or entirely with an aerosol-forming gel (not shown).

An exemplary eddy current flow in the susceptor casing <NUM> induced by an inductor, in particular an induction coil arranged around the casing, is indicated with arrows.

In <FIG> a perspective side view of a cup-shaped casing <NUM> with a corrugated side wall <NUM> is shown. The corrugations <NUM> extend from the bottom <NUM> to the opposite end of the casing <NUM>. The corrugations <NUM> get continuously more expressed from the bottom <NUM> into the direction of the opposite opening end. An exemplary eddy current flow in the susceptor casing <NUM> induced by an inductor, in particular an induction coil arranged around the casing, is indicated with arrows.

Positive locking means are not shown in <FIG>.

Exemplary data for casings as shown in <FIG> are: <NUM> to <NUM> susceptor material; <NUM> aerosol-forming gel; intended temperature for the aerosol-forming gel: about <NUM> degree Celsius to about <NUM> degree Celsius. Aerosol-generating rod segments with the mentioned parameters may achieve a vaping experience of a duration of about <NUM> seconds.

In <FIG> an example of a step-by-step manufacturing of a casing as shown in <FIG> is illustrated. A susceptor sheet material may be preformed into a cup-cake shape as shown in the left drawing of <FIG>. The radially outwardly directing side wall <NUM> of the cup-cake shaped casing is pressed radially inwardly until the casing <NUM> has a substantially same diameter over the entire length of the casing <NUM>.

The positive locking means for retaining the gel in the casing may subsequently be provided in the casing <NUM>, for example in one of more further manufacturing steps. Preferably, one or more positive locking means are provided in the casing in one further manufacturing step.

In <FIG> examples of positive locking means are shown. In <FIG> the ends of the side wall <NUM> of the susceptor casing <NUM> opposite the bottom <NUM> of the casing direct inwardly. Preferably, this is achieved by bending the end portion <NUM> of the side wall <NUM> of the casing radially inwardly. The end portion <NUM> then forms a rim diminishing the opening <NUM> of the casing. The plug of aerosol-forming gel <NUM> inside the casing <NUM> may not fall out or be forced out of the opening <NUM> of the casing <NUM> as a diameter of the gel plug is larger than the diameter of the opening <NUM>. The inwardly bent end portion <NUM> of the side wall <NUM> forms a positive lock for the gel <NUM> and has a retaining action for the gel in axial direction <NUM> of the casing <NUM>. In <FIG> the susceptor casing <NUM> is entirely filled with aerosol-forming gel.

In <FIG> next to the inwardly bent end portion <NUM> of the side wall <NUM>, the casing comprises radially inwardly directing protrusions <NUM>. The protrusions <NUM> are formed by deformation of the side wall <NUM>. The protrusions <NUM> are arranged in an intermediate section <NUM> of the casing <NUM>, in about <NUM> percent to <NUM> percent of the length or height of the casing. In <FIG> the protrusion is arranged at about <NUM> percent of the length of the casing <NUM>. Preferably, the protrusion <NUM> forms a rib that extends partially or entirely around the circumference of the casing. In <FIG> about half of the susceptor casing <NUM> is filled with aerosol-forming gel to about half the height of the casing <NUM>. The protrusion <NUM> forms a positive lock for the gel <NUM> without clearance. The inwardly bent end portions <NUM> form a positive lock with clearance due to the distance between the filling height of the aerosol-forming gel and the inwardly bent end portions <NUM>.

In <FIG> positive locking means are formed in the susceptor casing <NUM> by radially inwardly directing protrusions <NUM> arranged at different length positions of the casing <NUM>. A first protrusion <NUM> is arranged at about <NUM> percent of the length of the casing <NUM>, while a second protrusion <NUM> is arranged at about <NUM> percent of the length of the casing <NUM> counting from the bottom <NUM> of the casing <NUM>. The protrusions <NUM> are formed by deformation of the side wall <NUM> and form ribs that extend partially or entirely around the circumference of the casing <NUM>. The opening <NUM> of the casing <NUM> shown in <FIG> has as same diameter as the bottom <NUM> of the casing <NUM>.

In the shown examples of <FIG>, protrusions <NUM> are arranged opposite each other in the casing <NUM>. However, protrusions may also be arranged, for example, in a staggered manner over the height of the casing <NUM>. Several protrusions, for example <NUM> to <NUM> protrusions, may be arranged in the casing <NUM>. The sum of protrusions and further positive locking means retain the gel <NUM> in the casing <NUM> in axial direction.

<FIG> schematically shows an aerosol-forming article <NUM> comprising an aerosol-generating rod segment <NUM>. The aerosol-generating rod segment <NUM> is a rod element having a corrugated side wall <NUM>. The positive locking means are not shown in <FIG>.

The aerosol-forming article <NUM> is rod-shaped and comprises six segments that are arranged in an end-to-end position. The aerosol-forming article <NUM> has a mouth end comprising a filter segment <NUM> at its most proximal end or most downstream end. An aerosol-cooling segment <NUM> is arranged adjacent to and upstream of the filter segment <NUM>. An empty cavity <NUM> is arranged between the aerosol-cooling element <NUM> and the aerosol-forming rod segment <NUM>. At the distal end of the aerosol-generating article <NUM> two hollow acetate tube segments (HAT) <NUM>, <NUM> are arranged. The hollow acetate tube <NUM> arranged at the most distal end of the article <NUM> is a thin hollow acetate tube <NUM> and has a wall thickness smaller than the wall thickness of the hollow acetate tube <NUM> arranged adjacent the aerosol-generating rod segment <NUM>. The hollow acetate tube <NUM> has a wall thickness of about <NUM>. The thin hollow acetate tube <NUM> has a wall thickness of about <NUM>.

The plurality of segments is wrapped in a wrapper <NUM>, for example a paper or plastics wrapper. The individual segments may be individually wrapped before being assembled and wrapped with the wrapper <NUM> to form the rod-shaped aerosol-generating article <NUM>.

The wrapper <NUM> comprises a row of perforations <NUM> for an airflow to pass and enter the wrapper <NUM> through the perforations <NUM>. The perforations are arranged at an upstream end of the aerosol-generating rod segment <NUM>. The airflow having entered the wrapper <NUM> passes outside and along the susceptor casing into the direction of the proximal end of the article <NUM>. The airflow picks up vaporized substances from the heated aerosol-forming gel and forms an aerosol in the cavity <NUM>, is cooled down in the aerosol-cooling element <NUM> and filtered in the filter element <NUM>.

Exemplary values for the length of the individual segments of the article of <FIG> are: length for the thin HAT segment <NUM>: <NUM>, length of the HAT <NUM>: <NUM>, length of the aerosol-generating rod segment <NUM>: <NUM>, length of the cavity <NUM>: <NUM>, length of the aerosol-cooling element <NUM>: <NUM>, length of the mouthpiece filter element <NUM>: <NUM>. Total length of the article <NUM>: <NUM>.

In <FIG> an example of an aerosol-generating article <NUM> is schematically shown. The article comprises a plurality of segments wrapped in a wrapper <NUM>. The aerosol-generating rod segment <NUM> is arranged between a most distally arranged front segment <NUM> and an airflow directing element <NUM>.

The aerosol-generating rod segment <NUM> comprises a cup-shaped susceptor casing <NUM>. The cup-shaped susceptor casing <NUM> has a constant circular cross section and comprises an inwardly directing flange <NUM>, diminishing the size of the opening <NUM> of the casing <NUM>. The material of the casing <NUM> is, for example, aluminium or stainless steel, for example Sxx or S4xx, such as SS430.

The aerosol-forming gel <NUM> is arranged inside the casing <NUM> as well as outside the casing <NUM>. In the example shown in <FIG> the aerosol-generating rod segment <NUM> is a gel plug comprising the susceptor casing, which gel plug defines the size of the aerosol-generating rod segment <NUM>.

The front segment <NUM> comprises a ferrite bead <NUM>. The ferrite bead <NUM> may, for example, be ferrite K1 and may have a size of about <NUM> and a weight between <NUM> to <NUM>.

The ferrite bead <NUM> is arranged at a proximal end of the front segment <NUM>. By this, the ferrite bead <NUM> is arranged adjacent the aerosol-generating rod segment <NUM> and close to the bottom <NUM> of the casing <NUM> in the aerosol-generating rod segment <NUM>. By this, a heating of the casing <NUM> may be enhanced in a bottom region of the casing <NUM> opposite the opening <NUM> of the casing.

The airflow-directing element <NUM> comprises a truncated hollow cone <NUM>. The truncated end of the hollow cone <NUM> is directing versus the aerosol-generating rod segment <NUM>. Vaporized gel enters the cone through the truncated end and expands in the cone <NUM> to be distributed over the entire cross section of the article.

The wrapper <NUM> wrapping the article <NUM> and keeping the individual segments in place comprises perforations <NUM> at a length position of the article corresponding to a distal region of the airflow-directing element <NUM>. Air may enter the article <NUM> through the perforations <NUM> and gets into the airflow-directing element <NUM>. The air is first led in an upstream direction as the cone entry is arranged at a position more upstream in the article <NUM> than the perforations <NUM>. The air picks up vaporized gel and passes the cone in a downward direction. The aerosol comprising airflow <NUM> is then led further downstream to the mouth end of the article <NUM> (not shown).

In some examples the thickness of the susceptor material of the casing is <NUM> micrometer. In further rexamples the thickness of the susceptor material of the casing is <NUM> micrometer.

A casing <NUM> may, for example, have a weight of about <NUM> when empty and a weight of about <NUM> when filled with <NUM> gel.

In <FIG> the aerosol-generating article <NUM> comprises five segments. The aerosol-generating rod segment <NUM> is sandwiched between two hollow rod segments <NUM>, for example two hollow acetate tubes. The one hollow tube is arranged at the most distal end of the article <NUM>. Adjacent the more downstream arranged acetate tube <NUM> is an aerosol-cooling element <NUM> and a filter segment <NUM> at the most proximal end of the article <NUM>.

The two hollow tubes <NUM> may be of a same construction. In <FIG>, the hollow tube arranged at the most distal end of the article is shorter, for example by <NUM>-<NUM> shorter, than the more upstream arranged hollow tube. For example, the shorter hollow tube <NUM> may have a length of <NUM>. The longer hollow tube <NUM> may have a length of <NUM>. The hollow tubes have wall thicknesses of about <NUM>.

The article <NUM> shown in <FIG> comprises five segments: a front plug <NUM> followed by the aerosol-generating rod segment <NUM>, followed by a hollow tube segment <NUM> and a thin hollow tube segment <NUM>, followed by a filter segment <NUM> arranged at the most proximal end of the article <NUM>.

The article has a diameter <NUM> of <NUM> and a total length <NUM> of <NUM>. The total length <NUM> is made up by the length of the individual segments: filter segment <NUM>: <NUM>, hollow tubes each: <NUM>, aerosol-generating rod segment <NUM>: <NUM>, front plug <NUM>: <NUM>.

Perforations <NUM> in the wrapper <NUM> are arranged at a distance <NUM> of <NUM> from the most proximal end of the article <NUM>. The perforations <NUM> and the airflow entering the article through the perforations <NUM> just upstream of the filter element <NUM> may cause a turbulent flow in the thin hollow tube <NUM>. This may improve the filtering action of the aerosol containing airflow in the filter element <NUM>.

In <FIG> a manufacturing process of an aerosol-generating article <NUM> is shown in a simplified manner. In <FIG> a circular disc <NUM> of susceptor material has been cut-out from a susceptor sheet material, for example an aluminium foil or a stainless steel foil. The disc <NUM> is formed, preferably folded, into a cup-shaped susceptor <NUM> as shown in <FIG>. The bottom <NUM> of the susceptor is circular and flat and the side walls <NUM> of the cup-shaped susceptor <NUM> are corrugated. The corrugations are arranged along the length of the cup-shaped susceptor <NUM>.

As may be seen in <FIG>, the cup-shaped susceptor <NUM> is positioned within a hollow tube <NUM>, for example a cardboard tube such as a spiral-wound cardboard tube. The hollow tube <NUM> is positioned in a vertical manner. The cup-shaped susceptor is inserted with its bottom <NUM> first in the hollow tube through the top end <NUM> of the hollow tube <NUM>. The cup-shaped susceptor <NUM> is guided through the hollow tube <NUM> and positioned at the bottom end <NUM> of the hollow tube. The bottom <NUM> of the susceptor <NUM> may be flush with the bottom end <NUM> of the hollow tube <NUM>.

The cup-shaped form of the susceptor <NUM> simplifies insertion of the cup-shaped susceptor as the bottom <NUM> preferably has a smaller diameter than the diameter of the side walls <NUM> at the opening of the cup-shaped susceptor.

Preferably, the cup-shaped susceptor <NUM> is slightly clamped in the hollow tube <NUM> by spring force of the side walls <NUM>.

In <FIG>, the dosing tip <NUM> of a dosing device <NUM> is inserted through the top end <NUM> into the hollow tube <NUM> for dosing a defined amount of aerosol-forming gel <NUM> into the cup-shaped susceptor <NUM>. The gel <NUM>, for example containing nicotine, may be supplied in a liquid or pasty form and may subsequently dry and harden in the cup-shaped susceptor. The liquid or pasty gel <NUM> flows into the corrugations of the side walls <NUM> and provides a close contact of the gel with the susceptor material.

In a final step as shown in <FIG>, an endpiece <NUM> is inserted into the hollow tube <NUM>, also through the top end <NUM>. The endpiece <NUM> typically comprises one or several filter segments. Preferably, the endpiece <NUM> is a preassembled composition of segments arranged in an end-to-end position. The endpiece <NUM> may comprise segments influencing aerosol-formation or having a filtering effect. For example, the endpiece <NUM> may comprise, a filter, a diffuser, an aerosol-cooling element or an aerosol-directing element.

The endpiece <NUM> is positioned at the top end <NUM> of the hollow tube <NUM>. The endpiece <NUM> may be arranged flush with the top end of the hollow tube <NUM> or may be arranged in a slightly recessed manner forming an aerosol-generating article <NUM>.

The cup-shaped susceptor <NUM> shown in <FIG> may also be provided with positive locking means such as to retain the aerosol-forming gel in axial direction in the cup-shaped susceptor <NUM>.

<FIG> show an enlarged example of a folded, cup-shaped susceptor casing <NUM> having a flat bottom <NUM> in the form of a polygon. The side walls <NUM> are corrugated in a way such that some folds <NUM> of the side wall <NUM> extend from the circumference of the bottom <NUM> of the cup-shaped susceptor <NUM> to the center of the opposite end of the cup-shaped susceptor, thus closing the opening <NUM> of the cup-shaped susceptor to a more or less degree depending on the extent that the side walls <NUM> are folded. Some other folds <NUM> of the side walls <NUM> extend from the circumference of the bottom <NUM> of the cup-shaped susceptor <NUM> basically in a straight manner to the opposite end of the cup-shaped susceptor, thus defining the outer diameter of the cup-shaped susceptor <NUM>. Depending on the degree of folding the cup-shaped susceptor, the folds <NUM> of the side wall <NUM> direct radially outwards with respect to the bottom <NUM> to a more or less degree depending on the extent the side walls <NUM> are folded.

The folds <NUM> that continuously converge versus the opening of the cup-shaped susceptor <NUM> form positive locking means having a retaining action onto gel in the susceptor acting in the axial direction of the cup-shaped susceptor.

The side walls <NUM> of the cup-shaped susceptor <NUM> are also constructed to have a radial retaining force onto the cup-shaped susceptor itself, when the cup-shaped susceptor is used in an article as shown in <FIG>.

<FIG> are further examples of folded cup-shaped susceptors <NUM> having a bottom <NUM> in the form of a polygon. In <FIG>, the bottom <NUM> is folded and corrugated. The bottom <NUM> directs inwardly diminishing the volume of the cup-shaped susceptor and concentrating the susceptor material to a smaller area. In <FIG>, the bottom <NUM> is folded and corrugated and directs outwardly enlarging the volume of the cup-shaped susceptor <NUM>.

The folds of the side walls <NUM> may be folded in a similar manner as described in the example of <FIG>. The cup-shaped susceptors <NUM> may used as cup-shaped susceptor casings with positive locking means as well as cup-shaped susceptors having a retaining force on the casing itself to be fixed in its position when inserted and arranged in an aerosol-forming article as described in <FIG>.

<FIG> shows a bottom view, a side view and a top view of an aluminium casing <NUM>. The aluminium casing has a circular diameter with a small bottom <NUM>, side walls <NUM> having a larger diameter than the diameter of the bottom <NUM> and an inwardly bent rim <NUM> at the opposite opening <NUM> side of the casing. The size of the opening <NUM> of the casing <NUM> is defined by the extent of the rim <NUM> being bent inwardly. The rim <NUM> has the function to retain a gel in longitudinal axial direction in the casing <NUM>. The rim <NUM> also forms a surface for sealing a closing seal to the capsule <NUM>. Casings may be filled with aerosol-forming gel and sealed such that the so formed aerosol-generating rod segment may be stored for later incorporation into an inductively heatable aerosol-generating article <NUM>.

The casing <NUM> has been formed by deep drawing an aluminium disc, widening the side walls <NUM> of the casing and bending the rim <NUM>. The thickness of the aluminium used for the casing may, for example, be <NUM> micrometer or may be <NUM> micrometer for embossed aluminium. Other materials suitable for being inductively heated, deep drawn and bent may be used for forming the casing.

In <FIG> three sequentially arranged stations <NUM>,<NUM>,<NUM> in an aerosol-generating article manufacturing process are shown. In the first station <NUM>, a forming unit, the cup-shaped casing is formed. In the second station, an insertion unit, the cup-shaped casing is inserted into a coated cardboard tube, for example as described in <FIG> above. In the third station <NUM>, the filling unit, an aerosol-forming gel is filled into the susceptor casing with a dosing device <NUM>. The so manufactured semi-finished article may be further processed, for example as described with reference to <FIG>.

In <FIG> a first step of the casing forming in the forming unit <NUM> is shown. A cavity <NUM> in the lower part of the forming tool forms a mold.

The lower part of the forming tool comprises a vertically movable lower forming tool <NUM>, its function will be described in more detail below. The top surface of the lower forming tool <NUM> forms the bottom of the mold.

A blank of sheet material, such as an aluminium disc, is loaded into the forming unit <NUM> above the cavity <NUM>.

A plunger <NUM> is lowered, while the head <NUM> of the plunger is inserted into the cavity <NUM> from above. The plunger head <NUM> presses the aluminium disc into the cavity <NUM>.

The diameter of the plunger <NUM> is smaller than the diameter of the cavity <NUM>.

In order to widen the side walls of the semi-finishes casing <NUM>, the plunger head <NUM> is moved along the side wall of the mold. The movement of the plunger <NUM> and the position of the plunger head <NUM> during the side wall extension of the casing is shown in <FIG> and <FIG>.

<FIG> shows the movement path of the plunger head <NUM> in the cavity <NUM> for widening the side walls of the semi-finishes casing <NUM>. The plunger <NUM> moves from the center of the cavity <NUM> to one side of the cavity. It then rotates along the sides of the mold defining the cavity. The plunger <NUM> simultaneously circles and rotates in the cavity <NUM>. The position of the plunger <NUM> at a side of the cavity is shown in <FIG>. The rotation of the plunger <NUM> is indicated by arrow <NUM>.

For forming the rim and bending the upper portion of the side wall of the semi-finished casing <NUM>, the plunger <NUM> and the lower forming tool <NUM> are lifted in the direction of arrows <NUM> as shown in <FIG>.

The transfer plate <NUM> being part of the upper forming tool comprises a mold surface <NUM> with an inwardly directing edge mold <NUM>.

Upon lifting the lower forming tool <NUM> and plunger <NUM> the semi-finished capsule <NUM> is guided through the cavity <NUM> while the plunger head <NUM> remains in the centre of the semi-finished casing <NUM>. Upon pressing the semi-finished casing <NUM> against the edge mold <NUM> of the transfer plate <NUM>, the rim <NUM> of the casing <NUM> is formed.

A vacuum applied to the casing may ensure the correct placement of the casing during transfer.

In yet a further step as shown in <FIG>, the upper forming tool is lifter further and the lower forming tool <NUM> is lowered as indicated by arrows <NUM>, <NUM> for releasing the finished casing <NUM>.

Through the transfer plate <NUM>, the casing <NUM> is removed from the forming tool <NUM>.

The transfer plate <NUM> may then transfer the cup-shaped casing <NUM> to the next station <NUM> for insertion into a cardboard tube.

Claim 1:
Aerosol-generating rod segment (<NUM>) comprising a rod-shaped susceptor casing (<NUM>) and an aerosol-forming gel (<NUM>) contained in the rod-shaped susceptor casing, wherein the susceptor casing comprises a bottom (<NUM>), a side wall (<NUM>) and an opening (<NUM>) arranged opposite the bottom, and wherein the aerosol-forming gel is retained inside the susceptor casing in axial direction of the aerosol-generating rod segment by at least one positive locking means, wherein at least one of said at least one positive locking means is designed as an inwardly directed seam of the susceptor casing arranged adjacent to an end section of the susceptor casing, which end section is arranged opposite the bottom of the susceptor casing, characterized in that the side wall (<NUM>) of the susceptor casing (<NUM>) is corrugated, and in that the seam is formed by an inwardly bent end portion (<NUM>,<NUM>) of the side wall of the susceptor casing.