Aerosol generating article having a spiral airflow path

Abstract

The present invention relates to an aerosol-generating article (10) including a mouthpiece portion (12). The mouthpiece portion (12) includes an extruded material (22). The extruded material (22) is airtight. The extruded material (22) has a cylindrical shape. A helical airflow path (24) is disposed within the extruded material, which fluidly connects the upstream end face of the extruded material (22) to the downstream end face of the extruded material. The present invention further relates to a method for extruding an extruded material of an aerosol-generating article, and an extrusion die (48).

Description

Technical Field

[0001] The present invention relates to aerosol generating articles, a method for extruding an extrudate of an aerosol generating article, and an extrusion die.

Background Art

[0002] It is known to provide aerosol generating articles for generating inhalable vapors. Such articles may include an aerosol forming substrate heated to a temperature at which one or more components of the aerosol forming substrate volatilize without burning the aerosol forming substrate. The aerosol forming substrate may be provided as part of the substrate portion of the aerosol generating article. The aerosol generating article may have a rod shape for insertion of the aerosol generating article into a cavity of an aerosol generating device, such as a heating chamber. Since the temperature utilized for vaporization of the aerosol forming substrate is relatively low, it may not be necessary to provide a filter downstream of the substrate portion. However, having a hollow portion downstream of the substrate portion may be unpleasant for the user. Furthermore, the possibility that the aerosol forming substrate may fall off from the open end downstream of the aerosol forming article is not desirable for the user.

[0003] Aerosol generating articles that do not require a downstream filter are desirable. It is desirable to have an aerosol generating article that prevents the aerosol forming substrate from falling off the aerosol generating article downstream of the substrate portion of the aerosol generating article. It is desirable to have an aerosol generating article that makes the substrate portion of the aerosol generating article invisible.

Summary of the Invention

[0004] According to one embodiment of the present invention, an aerosol generating article that may include a mouthpiece portion is provided. The mouthpiece portion may include an extrudate. The extrudate may be airtight. The extrudate may have a cylindrical shape. A helical air flow path that fluidly connects the upstream end face of the extrudate to the downstream end face of the extrudate can be disposed within the extrudate.

[0005] According to one embodiment of the present invention, an aerosol generating article including a mouthpiece portion is provided. The mouthpiece portion includes an extruded material. The extruded material is airtight. The extruded material has a cylindrical shape. A helical airflow path is provided within the extruded material, which fluidly connects the upstream end face of the extruded material to the downstream end face of the extruded material.

[0006] Extruded materials can eliminate the need for downstream filters. In particular, extruded materials can prevent fine residues of the aerosol-forming substrate of aerosol-generating articles from detaching from the mouthpiece portion. Extruded materials may have sufficient filtration effect to replace downstream filters. This may be because heated, non-combustible aerosol-generating articles generate only small amounts of unwanted components that are sufficiently filtered by the extruded material.

[0007] Additionally, or alternatively, the extruded material may prevent the substrate portion of the aerosol-generating article from being fully exposed. This may be desirable because users may prefer a cleaner appearance of the aerosol-generating article than having the aerosol-forming substrate directly visible when looking into the hollow mouthpiece portion.

[0008] The extruded material may have an outer diameter that corresponds to the outer diameter of the aerosol-generating article, or an outer diameter that is slightly smaller than the outer diameter of the aerosol-generating article.

[0009] The extruded material may be disposed inside the mouthpiece portion. The mouthpiece portion may be hollow. The mouthpiece portion may be tubular. The mouthpiece portion may have a hollow cylindrical shape. The side walls of the mouthpiece portion may be made of cardboard. In addition to the extruded material, the mouthpiece portion may have only cardboard side walls. The extruded material may be disposed inside the hollow cylindrical interior of the mouthpiece portion, and preferably may fill the hollow cylindrical interior of the mouthpiece portion.

[0010] The extruded material may have an outer diameter that corresponds to the inner diameter of the mouthpiece portion of the aerosol-generating article, or an outer diameter that is slightly smaller.

[0011] The extruded material can form the mouthpiece portion. In this embodiment, the mouthpiece portion does not need to have cardboard side walls. In this embodiment, preferably, the mouthpiece portion consists only of the extruded material.

[0012] The extruded material can prevent lateral airflow into the mouthpiece area.

[0013] The helical airflow path can be arranged inside the extruded material, radially spaced apart from the periphery of the extruded material.

[0014] The extruded material can enable axial airflow through the mouthpiece portion via a helical airflow path.

[0015] The extruded material may be at least partially surrounded by wrapping paper. The wrapping paper may be arranged in addition to, or alternative to, the cardboard sidewalls. Preferably, the wrapping paper is arranged to wrap at least partially around the cardboard sidewalls of the mouthpiece portion in order to connect the mouthpiece portion to at least further portions of the aerosol generating article. Particularly preferably, the mouthpiece portion consists of the extruded material thus forming the interior of the mouthpiece portion and surrounded by the cardboard sidewalls. Particularly preferably, the cardboard sidewalls are at least partially wrapped by wrapping paper in order to connect the mouthpiece portion to at least one other portion of the aerosol generating article.

[0016] The extruded material may include at least two helical airflow paths. Preferably, the at least two helical airflow paths may be arranged within the extruded material so as to be fluidically separated from each other. In other words, the helical airflow paths may be fluidically separated within the extruded material.

[0017] The extruded material may include 2 to 16, preferably 4 to 8, preferably 6, helical airflow paths arranged within the extruded material that can fluidly connect the upstream end face of the extruded material to the downstream end face of the extruded material.

[0018] The spiral airflow paths can be arranged parallel to each other within the extruded material.

[0019] A spiral airflow path may have a triangular cross-section.

[0020] Alternatively, the helical airflow path may have a drop-shaped, circular, rectangular, or elliptical cross-section.

[0021] The aerosol-generating article may further include a substrate portion. The substrate portion may include an aerosol-forming substrate. The substrate portion may be disposed upstream of the mouthpiece portion.

[0022] The base portion may be in direct contact with the mouthpiece portion. Alternatively, further portions, such as a cooling portion, may be disposed between the base portion and the mouthpiece portion. The wrapping paper described herein may be partially wrapped around the upstream portion of the mouthpiece portion to connect the mouthpiece portion and this upstream portion. Thus, the wrapping paper may connect the mouthpiece portion to the base portion or further portions.

[0023] The extruded material may be opaque. Opaque extruded materials may, if desired, allow the aerosol-forming substrate of the substrate portion to be visible through the extruded material.

[0024] The radius of the helical airflow path may be at least 50% of the radius of the mouthpiece portion, preferably at least 60%, more preferably at least 70%, and most preferably at least 80%.

[0025] The pitch of the helical airflow path may be 0.3 to 3 times the length of the extruded material. The pitch of the helical airflow path may be 0.6 to 2 times the length of the extruded material. The pitch of the helical airflow path may be approximately the length of the extruded material.

[0026] The length of the extruded material can be measured along or parallel to the central axis in the long axis direction of the aerosol-generating article. The length of the mouthpiece portion can be measured along or parallel to the central axis in the long axis direction of the aerosol-generating article. The length of the extruded material can correspond to the length of the mouthpiece portion. In other words, the extruded material can have the same length as the mouthpiece portion. The central axis in the long axis direction of the aerosol-generating article can be the same as the central axis in the long axis direction of the extruded material. The central axis in the long axis direction of the aerosol-generating article can be the same as the central axis in the long axis direction of the mouthpiece portion.

[0027] The side wall of the mouthpiece portion can be coaxially aligned with the extruded material. The wrapping paper can be coaxially aligned with one or both of the side wall of the mouthpiece portion and the extruded material.

[0028] The helical airflow path can be disposed at the peripheral portion of the extruded material. The term "peripheral portion" can describe the disposition of the helical airflow path near the peripheral portion of the extruded material, in other words, below and in the vicinity of the peripheral surface of the extruded material. A disposition is preferred such that the lateral airflow to the extruded material is blocked so that only the axial airflow through the extruded material is enabled by the helical airflow path. The helical airflow path can be disposed closer to the peripheral portion of the extruded material than towards the central axis in the long axis direction of the extruded material.

[0029] This can be advantageous when the aerosol-forming substrate particles experience a greater centrifugal force when moving through the helical airflow path. This can enable these particles to be more reliably captured or decelerated while moving through the extruded material.

[0030] By disposing the helical airflow path at the peripheral portion of the extruded material, there may be a further advantage that the helical airflow path approaches the peripheral portion of the mouthpiece portion. In other words, by disposing the helical airflow path at the peripheral portion of the extruded material, the distance between the helical airflow path and the surrounding air can be shortened. This can result in more effective cooling of the air moving through the helical airflow path. Cooling of the air flowing through the helical airflow path can cause the volatilized aerosol-forming matrix to condense, resulting in the formation of an inhalable aerosol. This may eliminate the need to provide a separate cooling portion for the aerosol-generating article or at least synergistically improve aerosol formation together with a separate cooling portion.

[0031] The helical airflow path may have a cross-sectional area of 5% to 50% of the cross-sectional area of the extruded material.

[0032] The extruded material includes, preferably consists of, cellulose acetate, foamed acetate, foamed PLA polymer compound or cellulose compound.

[0033] The extruded material can be made from one or both of biodegradable materials and recyclable materials.

[0034] The extruded material can be non-porous. The extruded material can be liquid-tight. The extruded material can be airtight.

[0035] The helical airflow path passing through the extruded material can be the only way for air to flow through the extruded material.

[0036] The helical airflow path can be configured as a groove in the extruded material.

[0037] The helical airflow path may be narrower towards the peripheral portion of the helical airflow path. In other words, the cross-section of the helical airflow path may be narrower in the radially outward direction.

[0038] This may have the advantage that aerosol-forming substrate particles from the upstream substrate portion of the aerosol-generating article can be more effectively captured in the helical airflow path. More specifically, aerosol-forming substrate particles drawn in through the helical airflow path may experience centrifugal force and therefore may be pressed against the radially outer portion of the helical airflow path while moving through it. Configuring the helical airflow path with a narrow radially outer portion allows for more effective capture of these substrate particles as they are drawn out through the extruder.

[0039] The helical airflow path may widen towards the central axis of the long axis of the extruded material. In other words, the cross-section of the helical airflow path may widen in the radially inward direction.

[0040] The draw resistance of the mouthpiece portion containing the extruded material can be ignored because a helical airflow path is provided through the extruded material. At the same time, as described herein, the extruded material can prevent undesirable free particles of the aerosol-forming substrate from being drawn through the mouthpiece portion. Furthermore, as described herein, the extruded material can prevent the aerosol-forming substrate from being exposed through the undesirable, hollow mouthpiece portion.

[0041] The present invention further relates to a method for extruding an extruded material of an aerosol-generating article described herein. The method is:

[0042] This involves extruding a continuous rod of extruded material while rotating the extrusion die described herein in order to form a helical airflow path.

[0043] The rotation of the extrusion die can create a helical airflow path within the extruded material.

[0044] The method may include a cooling step for the extruded material.

[0045] The method may include a step of drawing out the extruded material.

[0046] The method may include a step of cutting the extruded material.

[0047] The present invention further relates to an extrusion die, and more preferably to the method described herein. The extrusion die may comprise an extrusion opening and at least one solid triangular prism disposed within the extrusion opening.

[0048] A solid triangular prism can also be called a mandrel.

[0049] When an extrusion die is used in the method herein, which includes rotation of the extrusion die, the rotation of the extrusion die forms a helical airflow path, so the solid triangular prism can be linear.

[0050] A solid triangular prism may have a helical shape. This is particularly preferable when the extrusion molding is performed in a fixed extrusion die, in which case the helical airflow path is formed by the helical shape of the solid triangular prism.

[0051] Particularly preferably, the solid triangular prism has a helical shape and is used in the method herein, in which the extrusion die is rotated. In this case, the helical airflow path is formed by a synergistic combination of rotating the extrusion die and giving the solid triangular prism a helical shape. The combination of rotation of the extrusion die and the helical shape of the solid triangular prism creates a helical airflow path within the extruded material.

[0052] In general, if different cross-sectional shapes of the triangular helical airflow path described herein are desired, a solid triangular prism may instead be provided as a solid cylinder having a different cross-sectional shape. For example, instead of a solid triangular prism, a solid cylinder having a teardrop, circular, rectangular, or elliptical cross-section may be used.

[0053] For each individual helical airflow path, the extrusion die may include a solid cylinder of a corresponding shape.

[0054] Aerosol-generating articles can be used in aerosol generators. Aerosol-generating articles can be inserted into the cavities of aerosol generators. Aerosol generators can heat the aerosol-forming substrate of the aerosol-generating article, thereby generating an inhalable aerosol.

[0055] As used herein, the terms “proximal,” “distal,” “downstream,” and “upstream” are used to describe the relative position of a component or part of a component of an aerosol generator with respect to the direction in which the user inhales the aerosol generator during use.

[0056] An aerosol generator may have a mouth end through which, during use, aerosols exit the aerosol generator and are delivered to the user. The mouth end may also be called the proximal end. During use, the user inhales the proximal or mouth end of the aerosol generator to inhale the aerosol generated by the aerosol generator. Alternatively, the user may inhale directly an aerosol-generating article inserted into an opening at the proximal end of the aerosol generator. The opening at the proximal end may be a cavity opening. The cavity may be configured to receive an aerosol-generating article. The aerosol generator has a distal end opposite to the proximal or mouth end. The proximal or mouth end of the aerosol generator may also be called the downstream end, and the distal end of the aerosol generator may also be called the upstream end. Components of the aerosol generator, or parts of components, may be described as being upstream or downstream of each other based on their relative positions between the proximal, downstream, or mouth end of the aerosol generator and the distal or upstream end of the aerosol generator.

[0057] As used herein, “aerosol generator” refers to a device that generates an aerosol by interacting with an aerosol-forming substrate. The aerosol-forming substrate may be part of an aerosol-generating article, for example, part of a smoking article. The aerosol generator may be a smoking device that interacts with the aerosol-forming substrate of an aerosol-generating article to generate an aerosol that can be directly inhaled into the user's lungs through the user's mouth. The aerosol generator may be a holder. The device may be an electrically heated smoking device. The aerosol generator may comprise a housing, an electrical circuit, a power supply, a heating chamber, and a heating element.

[0058] As used herein in relation to the present invention, the term “smoking” in relation to apparatus, articles, systems, substrates, or otherwise does not refer to conventional smoking in which the aerosol-forming substrate is completely or at least partially burned. The aerosol-generating apparatus of the present invention is configured to heat the aerosol-forming substrate to a temperature below the combustion temperature of the aerosol-forming substrate, but above the temperature at which one or more volatile compounds of the aerosol-forming substrate are released, in order to form an inhalable aerosol.

[0059] The aerosol generator may include an electrical circuit. The electrical circuit may include a microprocessor, which may be a programmable microprocessor. The microprocessor may be part of a controller. The electrical circuit may include further electronic components. The electrical circuit may be configured to regulate the supply of power to a heating element. Power may be supplied to the heating element continuously following the startup of the aerosol generator, or intermittently, such as with each smoke extraction. Power may be supplied to the heating element in the form of current pulses. The electrical circuit may be configured to monitor the electrical resistance of the heating element and, preferably, control the supply of power to the heating element in accordance with the electrical resistance of the heating element.

[0060] An aerosol generator may have a power source, typically a battery, within its main body. In one embodiment, the power source is a lithium-ion battery. Alternatively, the power source may be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery (e.g., a lithium-cobalt battery, lithium iron phosphate, lithium titanate, or lithium polymer battery). Alternatively, the power source may be another form of charge storage device, such as a capacitor. The power source may require recharging and may have a capacity that allows for the storage of sufficient energy for one or more use experiences. For example, the power source may have a capacity sufficient to continuously generate aerosols for a period of about six minutes, or for periods of multiples of six minutes. In another embodiment, the power source may have a capacity sufficient to provide a predetermined number of fume extractions or discontinuous activation of a heating element.

[0061] The cavity of the aerosol generator may have an open end into which an aerosol generating article is inserted. The open end may be the proximal end. The cavity may have a closed end opposite the open end. The closed end may be the base of the cavity. The closed end may be closed except for providing an air opening located within the base. The base of the cavity may be flat. The base of the cavity may be circular. The base of the cavity may be located upstream of the cavity. The open end may be located downstream of the cavity. The cavity may have an elongated extension. The cavity may have a longitudinal axis. The longitudinal axis may be a direction extending between the open end and the closed end along the longitudinal axis. The longitudinal axis of the cavity may be parallel to the longitudinal axis of the aerosol generator.

[0062] The cavity may be configured as a heating chamber. The cavity may have a cylindrical shape. The cavity may have a hollow cylindrical shape. The cavity may have a shape corresponding to the shape of the aerosol-generating article received inside the cavity. The cavity may have a circular cross-section. The cavity may have an elliptical or rectangular cross-section. The cavity may have an inner diameter corresponding to the outer diameter of the aerosol-generating article.

[0063] The airflow channel may extend through the cavity. Ambient air may be drawn through the airflow channel into the aerosol generator, into the cavity, and toward the user. Downstream of the cavity, a mouthpiece may be provided, or the user may inhale the aerosol generating article directly. The airflow channel may extend through the mouthpiece.

[0064] In any aspect of this disclosure, the heating element may include an electrically resistive material. Suitable electrically resistive materials include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilide), carbon, graphite, metals, alloys, and composite materials made of ceramic and metallic materials. Such composite materials may include doped ceramics or undoped ceramics. An example of a suitable doped ceramic is doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum platinum, gold, and silver. Examples of suitable metallic alloys include stainless steel, nickel-containing, cobalt-containing, chromium-containing, aluminum-containing, titanium-containing, zirconium-containing, hafnium-containing, niobium-containing, molybdenum-containing, tantalum-containing, tungsten-containing, tin-containing, gallium-containing, manganese-containing, gold-containing, and iron-containing alloys, as well as nickel, iron, cobalt, stainless steel-based superalloys, Timetal®, and iron-manganese-aluminum alloys. In composite materials, the electrical resistive material may be embedded in, sealed in, or coated with an insulating material, depending on the required energy transfer dynamics and external physicochemical properties, or vice versa.

[0065] As described, in any aspect of the present disclosure, a heating element may be part of an aerosol generator. The aerosol generator may comprise an internal heating element, an external heating element, or both an internal and an external heating element, where “internal” and “external” refer to the aerosol-forming substrate. The internal heating element may take any suitable form. For example, the internal heating element may take the form of a heating blade. Alternatively, the internal heater may take the form of a casing or substrate having different conductive or electrically resistive metal tubes. Alternatively, the internal heating element may be one or more heating needles or rods passing through the center of the aerosol-forming substrate. Other alternatives include heating wires or filaments, e.g., Ni-Cr (nickel-chromium), platinum, tungsten, or alloy wires or heating plates. Optionally, the internal heating element may be placed in or on a rigid carrier material. In one such embodiment, the electrically resistive heating element may be formed using a metal having a clear relationship between temperature and resistivity. In such an exemplary device, the metal may be formed as a track on a suitable insulating material such as ceramic, and then sandwiched between other insulating materials such as glass. The heater thus formed can be used during operation to both heat a heating element and to monitor its temperature.

[0066] The external heating element can take any suitable form. For example, the external heating element may take the form of one or more flexible heating foils on a dielectric substrate such as polyimide. The flexible heating foils may be shaped to fit around a substrate receiving cavity. Alternatively, the external heating element may take the form of a metal grid, a flexible printed circuit board, a molded interconnect (MID), a ceramic heater, a flexible carbon fiber heater, or may be formed on a substrate of a suitable shape using a coating technique such as plasma deposition. The external heating element may also be formed using a metal that has a clear relationship between temperature and resistivity. In such an exemplary device, the metal may be formed as a track between two layers of a suitable insulating material. The external heating element thus formed may be used both for heating the external heating element and for monitoring its temperature during operation.

[0067] As an alternative to electrically resistive heating elements, heating elements can be configured as inductive heating elements. Inductive heating elements may comprise an induction coil and a susceptor. Generally, a susceptor is a material that has the ability to generate heat when penetrated by an alternating magnetic field. When located within an alternating magnetic field, if the susceptor is conductive, typically, eddy currents are induced by the alternating magnetic field. If the susceptor is magnetic, typically, another effect contributing to heating is generally called hysteresis loss. Hysteresis loss arises primarily from the movement of magnetic domain blocks within the susceptor. This is because the magnetic orientations of these domains align with the alternating inductive magnetic fields. Another effect contributing to hysteresis loss is when magnetic domains expand or contract within the susceptor. Generally, all these changes occurring at or below the nanoscale within the susceptor are called "hysteresis loss" because they generate heat within the susceptor. Therefore, if the susceptor is both magnetic and conductive, both hysteresis loss and eddy current generation will contribute to the heating of the susceptor. If the susceptor is magnetic but not conductive, hysteresis loss will be the only means by which the susceptor will be heated when penetrated by an alternating magnetic field. According to the present invention, the susceptor may be conductive or magnetic, or both conductive and magnetic. An alternating magnetic field generated by one or more induction coils heats the susceptor, which then transfers heat to the aerosol-forming substrate, thereby forming an aerosol. Heat transfer may be mainly by conduction. Such heat transfer is best when the susceptor is in close thermal contact with the aerosol-forming substrate.

[0068] As used herein, the term “aerosol-generating article” refers to an article comprising an aerosol-forming substrate having the ability to release volatile compounds capable of forming aerosols. For example, an aerosol-generating article may be a smoking article that generates an aerosol that can be directly inhaled into the user's lungs through the user’s mouth. An aerosol-generating article may be disposable.

[0069] As used herein, the term “aerosol-forming substrate” refers to a substrate having the ability to release one or more volatile compounds that can form aerosols. Such volatile compounds may be released by heating the aerosol-forming substrate. Conveniently, the aerosol-forming substrate may be part of an aerosol-generating article or a smoking article.

[0070] The aerosol-forming substrate may be a solid aerosol-forming substrate. The aerosol-forming substrate may be disposed on a portion of the substrate. The aerosol-forming substrate may contain both solid and liquid components. The aerosol-forming substrate may contain a tobacco-containing material that contains volatile tobacco-flavored compounds released from the substrate upon heating. The aerosol-forming substrate may contain non-tobacco materials. The aerosol-forming substrate may contain an aerosol-forming body that facilitates the formation of a high-density and stable aerosol. Examples of suitable aerosol-forming bodies include glycerin and propylene glycol.

[0071] The aerosol generating substrate preferably comprises homogenized tobacco material, an aerosol forming body, and water. Providing homogenized tobacco material may improve aerosol generation and the nicotine content and flavor profile of the aerosol generated during heating of the aerosol generating article. Specifically, the process of producing homogenized tobacco involves a process of crushing tobacco leaves, which allows for more effective release of nicotine and flavor during heating. [Brief explanation of the drawing]

[0072] [Figure 1] Figure 1 shows a side view of an aerosol generating article including a mouthpiece portion according to the present invention. [Figure 2] Figure 2 shows a side view of the extruded material of the mouthpiece portion of the aerosol generating article. [Figure 3] Figure 3 shows a side view of aerosol-forming substrate particles being drawn in through the extruder. [Figure 4]Figure 4 shows a top view of the aerosol-forming substrate particles being drawn in through the extruder. [Figure 5] Figures 5A and 5B show different cross-sectional shapes of the extruded material for the mouthpiece portion. [Figure 6] Figure 6 shows a side view of the extrusion method of the present invention. [Figure 7] Figure 7 shows an exploded view of the extrusion die of the present invention. [Figure 8] Figure 8 shows a front view of the extrusion die. [Figure 9] Figure 9 shows a cross-sectional side view of the extrusion die. [Figure 10] Figure 10 shows a further embodiment of the extrusion die. [Modes for carrying out the invention]

[0073] A non-exclusive list of non-limiting embodiments is provided below. One or more features of these embodiments may be combined with one or more features of any of the features described above, for example, one or more features of other embodiments, forms, or aspects described herein.

[0074] Example 1. An aerosol generating article including a mouthpiece portion, wherein the mouthpiece portion includes an extruded material, the extruded material is airtight, the extruded material has a cylindrical shape, and a helical airflow path is disposed within the extruded material, which fluidly connects the upstream end face of the extruded material to the downstream end face of the extruded material. Example 2. The aerosol generating article according to Example 1, wherein the extruded material has an outer diameter corresponding to or slightly smaller than the outer diameter of the aerosol generating article. Example 3. An aerosol generating article according to either Example 1 or 2, wherein the extruded material is disposed inside the mouthpiece portion. Example 4. An aerosol generating article according to any one of Examples 1 to 3, wherein the extruded material forms the mouthpiece portion. Example 5. An aerosol-generating article according to any one of Examples 1 to 4, wherein the extruded material is at least partially surrounded by wrapping paper. Example 6. An aerosol generating article according to any one of Examples 1 to 5, comprising 2 to 16, preferably 4 to 8, preferably 6, helical airflow paths, wherein the extruded material is disposed within the extruded material and the upstream end face of the extruded material is fluidly connected to the downstream end face of the extruded material. Example 7. The aerosol-generating article according to Example 6, wherein the helical airflow path is fluidically separated within the extruded material. Example 8. The aerosol generating article according to Example 6 or 7, wherein the spiral airflow path is arranged parallel to the extruded material. Example 9. An aerosol generating article according to any one of Examples 1 to 8, wherein the helical airflow path has a triangular cross-section. Example 10. The aerosol generating article according to any one of Examples 1 to 9, further comprising a base portion, the base portion comprising an aerosol-forming base, and the base portion being disposed upstream of the mouthpiece portion. Example 11. An aerosol-generating article according to any one of Examples 1 to 10, wherein the extruded material is opaque. Example 12. An aerosol generating article according to any one of Examples 1 to 11, wherein the radius of the helical airflow path is at least 50%, preferably at least 60%, more preferably at least 70%, and most preferably at least 80% of the radius of the mouthpiece portion. Example 13. An aerosol generating article according to any one of Examples 1 to 12, wherein a spiral airflow path is arranged around the periphery of the extruded material. Example 14. An aerosol generating article according to any one of Examples 1 to 13, wherein the helical airflow path has a cross-sectional area of ​​5% to 50% of the cross-sectional area of ​​the extruded material. Example 15. An aerosol-generating article according to any one of Examples 1 to 14, wherein the extruded material comprises, preferably, cellulose acetate, foamed acetate, foamed PLA polymer compound, or cellulose compound. Example 16. An aerosol-generating article according to any one of Examples 1 to 15, wherein the extruded material is non-porous. Example 17. An aerosol generating article according to any one of Examples 1 to 16, wherein the helical airflow path narrows toward the periphery of the helical airflow path. Example 18. A method for extruding an extruded material of an aerosol-generating article described in any of Examples 1 to 17, - A method comprising extruding a continuous rod of extruded material while rotating an extrusion die to form a helical airflow path. Example 19. Preferably, an extrusion die for the method of Example 18, comprising an extrusion opening and at least one solid triangular prism disposed in the extrusion opening. Example 20. An extrusion die according to Example 19, wherein a solid triangular prism has a helical shape.

[0075] Features described in relation to one embodiment may be equally applicable to other embodiments of the present invention.

[0076] The present invention will be further described with reference to the attached drawings, for illustrative purposes only.

[0077] Figure 1 shows an aerosol generating article 10. The aerosol generating article 10 includes a mouthpiece portion 12 according to the present invention. The aerosol generating article 10 further comprises an optional portion 14 such as a cooling portion, a base portion 16 including an aerosol forming substrate, and a front plug.

[0078] The mouthpiece portion 12 includes or is made from an extruded material 22, as described with reference to Figures 2-5 below.

[0079] The optional portion 14 is preferably configured as a cooling portion. The optional portion 14 may be tubular. The optional portion 14 may have cardboard side walls. The optional portion 14 may include perforations in its side walls to allow ambient air to be drawn into the optional portion 14.

[0080] The base portion 16 comprises an aerosol-forming base.

[0081] The forward plug is a solid plug made of acetate tow to prevent the aerosol-forming substrate from falling off the upstream end of the aerosol-generating article 10.

[0082] The arrows in Figure 1 indicate the direction in which air is drawn through the aerosol generating article 10. Downstream 20, the user can inhale the generated aerosol. The user can inhale the generated aerosol by placing their lips directly around the outer circumference of the mouthpiece portion 12.

[0083] Figure 2 shows the extruded material 22 of the mouthpiece portion 12. The mouthpiece portion 12 may consist of the extruded material 22. Alternatively, the extruded material 22 may be disposed on the inside of the side wall of the mouthpiece portion 12. Such side wall of the mouthpiece portion 12 may be made of cardboard. Furthermore, wrapping paper may be provided (not shown) to connect the mouthpiece portion 12 to the optional portion 14 or the base portion 16. The wrapping paper may wrap around at least a portion of the mouthpiece portion 12. The wrapping paper may wrap around at least a portion of the optional portion 14 or the base portion 16. In addition to, or alternatively to, the wrapping paper may be provided to wrap one or more of the portions of the aerosol generating article 10 for attachment of these portions.

[0084] As shown in Figure 2, the extruded material 22 has a cylindrical shape. The extruded material 22 is airtight. The extruded material 22 includes a helical airflow path 24. The helical airflow path 24 allows air to be drawn through the extruded material 22 along or parallel to the longitudinal central axis 26 of the extruded material 22. The longitudinal central axis 26 of the extruded material 22 is the same as the longitudinal central axis 26 of the mouthpiece portion 12 and the longitudinal central axis 26 of the aerosol generating article 10.

[0085] The helical airflow path 24 has a triangular cross-section. The helical airflow path 24 narrows near its periphery. The helical airflow path 24 widens toward the central axis of the long axis of the extruded material 22. This results in an increase in the centrifugal force 28 acting on the free particles of the aerosol-forming substrate drawn through the helical airflow path 24, as will be explained in more detail with reference to Figures 3 and 4 below, and as a result the aerosol-forming substrate also becomes trapped of such specific particles.

[0086] As shown in Figure 2, the pitch of the helical airflow path 24 is similar to or the same as the length of the extruded material 22. The length of the extruded material 22 is measured along the central axis 26 of the extruded material 22 in the longitudinal direction. The helical airflow path 24 has an air intake at the upstream end face 30 of the extruded material 22. The helical airflow path 24 has an air outlet 32 ​​at the downstream end face of the extruded material 22.

[0087] Figure 2 shows four exemplary individual helical airflow paths 24. However, this number is illustrative only. The helical airflow paths 24 may include a single helical airflow path 24, or up to 16 helical airflow paths 24, particularly preferably six helical airflow paths 24.

[0088] Figure 3 shows an exemplary single free air outlet 34 of the aerosol-forming substrate drawn in through the helical airflow path 24 of the extruded material 22. Due to the helical shape of the helical airflow path 24, a centrifugal force 28 acts on the single air outlet 34, pushing it toward the periphery of the helical airflow path 24. Due to the radially outward narrowing shape of the helical airflow path 24 (corresponding to the periphery of the helical airflow path 24), the free air outlet 34 fits into the narrow portion of the helical airflow path 24. As a result, the air outlet 34 is filtered by the extruded material 22 and does not reach the air outlet 32.

[0089] Figure 4 shows a top view of the filtration action in Figure 3. Figure 4 shows in more detail the centrifugal force 28 acting on the free air outlet 34 of the aerosol-forming substrate. Furthermore, Figure 4 shows how the air outlet 34 is further pushed toward the narrow peripheral portion of the helical airflow path 24 as it moves through it. Finally, the air outlet 34 becomes trapped between the walls of the airflow path at its peripheral portion. The triangular shape of the helical airflow path 24 helps to trap the air outlet 34 by trapping it between the narrowed walls of the helical airflow path 24.

[0090] Figures 5A and 5B show examples of different cross-sectional shapes of the helical airflow path 24. Figure 5A shows a pentagonal cross-sectional shape of the helical airflow path 24. Figure 5B shows a drop-shaped cross-sectional shape of the helical airflow path 24. The different cross-sectional shapes of the helical airflow path 24 have in common that the helical airflow path 24 narrows towards its periphery, allowing particles of the aerosol-forming substrate to be trapped within it.

[0091] Figure 6 shows an extruder 36 for extruding the extruded material 22. The extruder 36 includes an area into which the raw material 38 is inserted. The material is then processed by an extruder 40, and the extrusion rod 42 of the material is pulled out through a cooling unit 44 by a traction system 46. The extruded material 22 can then be cut into suitable portions for placement within or forming the mouthpiece portion 12.

[0092] Figure 7 shows a more detailed view of the extrusion die 48 used in the downstream region of the extruder 40. The processing direction of the extruded material 22 is indicated by the arrows in Figure 7. The material exits through an outlet hole 50 located in the extruder outlet plate 52 of the extruder 40. The material then enters the mandrel plate 54 through an opening 56. The mandrel plate 54 contains a solid triangular prism 58 (also referred to as the “mandrel”). The solid triangular prism 58 is straight. The mandrel plate 54 is configured to be movable together with the solid triangular prism 58. More specifically, the mandrel plate 54 can be rotated together with the solid triangular prism. The mandrel plate 54, together with the solid triangular prism, is configured to be rotatable during the extrusion process so that the helical airflow path 24 described herein is formed within the extruded material 22.

[0093] A spacer 60 is provided downstream of the mandrel plate 54. A mold cap 62, including a mold outlet 64, is provided downstream of the spacer 60. The extruded material 22 is then cooled, pulled out by a traction system 46, and cut into pieces of the appropriate shape.

[0094] Figure 8 shows a front view of the extrusion die 48. In particular, Figure 8 depicts the arrangement of a solid triangular prism 58 such that a helical airflow path 24 is formed inside the extruded material 22, close to the outer circumference of the extruded material 22, as illustrated in Figures 2 to 5.

[0095] Figure 9 is a cross-sectional side view along the line A-A' in Figure 8. In particular, Figure 9 shows the assembled configuration of the extrusion die 48 shown in the exploded view of Figure 7.

[0096] Figure 10 shows an alternative configuration of the mandrel. In the configuration of Figure 10, the mandrel is configured as a solid helical column 66 instead of a solid triangular prism 58. The solid helical column 66 has a helical shape. The helical shape of the solid helical column 66, together with the solid cylinder, forms a helical airflow path 24 during the extrusion process without requiring rotation of the mandrel plate 54. If beneficial, the mandrel plate 54 can still be rotated together with the solid helical column 66. However, the helical shape of the helical airflow path 24 may be essentially formed within the rotational motion of the mandrel plate 54 together with the solid helical column 66, due to the helical shape of the solid helical column 66.

Claims

1. An aerosol generating article including a mouthpiece portion, wherein the mouthpiece portion includes an extruded material, the extruded material is airtight, the extruded material has a cylindrical shape, a helical airflow path is disposed within the extruded material that fluidly connects the upstream end face of the extruded material to the downstream end face of the extruded material, and the helical airflow path is disposed on the periphery of the extruded material.

2. The aerosol generating article according to claim 1, wherein the extruded material has an outer diameter corresponding to or slightly smaller than the outer diameter of the aerosol generating article.

3. The aerosol generating article according to claim 1 or 2, wherein the extruded material is disposed inside the mouthpiece portion.

4. The aerosol generating article according to any one of claims 1 to 3, wherein the extruded material forms the mouthpiece portion.

5. The aerosol generating article according to any one of claims 1 to 4, wherein the helical airflow path has a triangular cross-section.

6. The aerosol generating article according to any one of claims 1 to 5, wherein the aerosol generating article further comprises a base portion, the base portion comprises an aerosol forming base, and the base portion is disposed upstream of the mouthpiece portion.

7. The aerosol generating article according to any one of claims 1 to 6, wherein the radius of the helical airflow path is at least 50% of the radius of the mouthpiece portion, preferably at least 60% of the radius of the mouthpiece portion, more preferably at least 70% of the radius of the mouthpiece portion, and most preferably at least 80% of the radius of the mouthpiece portion.

8. The aerosol generating article according to any one of claims 1 to 7, wherein the helical airflow path has a cross-sectional area of ​​5% to 50% of the cross-sectional area of ​​the extruded material.

9. The aerosol generating article according to any one of claims 1 to 8, wherein the extruded material comprises, preferably, cellulose acetate, foamed acetate, foamed PLA polymer compound, or cellulose compound.

10. The aerosol generating article according to any one of claims 1 to 9, wherein the extruded material is non-porous.

11. The aerosol generating article according to any one of claims 1 to 10, wherein the helical airflow path narrows toward the periphery of the helical airflow path.

12. A method for extruding an extruded material of an aerosol-generating article according to any one of claims 1 to 11, A method comprising rotating an extrusion die having a solid triangular prism having a helical shape, thereby extruding a continuous rod of extruded material to form a helical airflow path.

13. Preferably, an extrusion die for the method according to claim 12, comprising an extrusion opening and at least one solid triangular prism disposed in the extrusion opening.

14. The extrusion die according to claim 13, wherein the solid triangular prism has a helical shape.

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