Method for Manufacturing Aerosol Generating Articles

Abstract

A method for continuously manufacturing aerosol generating articles includes: (i) providing a continuous web of an aerosol generating substrate; (ii) applying at least one susceptor patch to a surface of the continuous web of aerosol generating substrate; (iii) cutting the continuous web of aerosol generating substrate and the at least one susceptor patch applied to the surface thereof to form a plurality of aerosol generating strips and a plurality of susceptor strips; and (iv) forming the plurality of aerosol generating strips and the plurality of susceptor strips into a continuous rod.

Claims

1. A method for continuously manufacturing aerosol generating articles, the method comprising: (i) providing a continuous web of an aerosol generating substrate; (ii) applying at least one susceptor patch to a surface of the continuous web of aerosol generating substrate; (iii) cutting the continuous web of aerosol generating substrate and the at least one susceptor patch applied to the surface thereof to form a plurality of aerosol generating strips and a plurality of susceptor strips; and (iv) forming the plurality of aerosol generating strips and the plurality of susceptor strips into a continuous rod.

2. The A-method according to claim 1, wherein step (iii) comprises simultaneously cutting the continuous web of the aerosol generating substrate and the at least one susceptor patch applied to the surface thereof.

3. The A-method according to claim 1, wherein step (iii) is performed using a rotary cutter unit.

4. The method according to claim 3, wherein the rotary cutter unit includes a first cutting drum having circumferentially extending first cutting formations and a second cutting drum having circumferentially extending second cutting formations, and wherein the first and second cutting formations cooperate to cut the continuous web of aerosol generating substrate and the at least one susceptor patch applied to the surface thereof to form the plurality of aerosol generating strips and the plurality of susceptor strips.

5. The method according to claim 1, wherein each of the plurality of aerosol generating strips and each of the plurality of susceptor strips has a width of between approximately 0.5 mm and 2.0 mm.

6. The method according to claim 1, wherein step (ii) comprises adhering the at least one susceptor patch to the surface of the continuous web of the aerosol generating substrate using an adhesive.

7. The method according to claim 6, wherein the method further comprises, after step (ii) and prior to step (iii), heating the adhesive to cure or set the adhesive.

8. The method according to claim 1, wherein the continuous web of the aerosol generating substrate provided in step (i) includes a substantially flat surface with a centre line, and step (ii) comprises applying the at least one susceptor patch to the substantially flat surface substantially along the centre line.

9. The method according to claim 1, wherein: step (ii) comprises consecutively applying a plurality of susceptor patches to the surface of the continuous web of aerosol generating substrate with a predefined and constant spacing between each successive susceptor patch; and step (iii) comprises cutting the continuous web of the aerosol generating substrate and the plurality of susceptor patches applied to the surface thereof to form a plurality of aerosol generating strips and a plurality of susceptor strips.

10. The method according to claim 1, wherein the at least one susceptor patch has a length of between 5 mm and 50 mm.

11. The method according to claim 1, wherein the method further comprises: (v) cutting the continuous rod to form a plurality of individual aerosol generating articles.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG. 1a is a diagrammatic cross-sectional side view of an aerosol generating article;

[0033] FIG. 1b is a diagrammatic cross-sectional view along the line A-A in FIG. 1a;

[0034] FIG. 2a is a diagrammatic illustration of an apparatus and method according to the present disclosure for manufacturing the aerosol generating article illustrated in FIGS. 1a and 1b;

[0035] FIG. 2b is a plan view of an aerosol generating substrate and susceptor patches as the aerosol generating substrate and susceptor patches move in the direction shown by the arrow through the apparatus illustrated in FIG. 2a;

[0036] FIG. 3 is a plan view of a section of a continuous web of susceptor material showing adhesive areas and non-adhesive areas;

[0037] FIG. 4 is a functional illustration of part of the apparatus and method of FIG. 2a schematically illustrating the formation of susceptor patches from a continuous web of susceptor material and the application of the susceptor patches to a surface of a continuous web of aerosol generating substrate;

[0038] FIG. 5 is a diagrammatic perspective view of a susceptor cutting unit; and

[0039] FIG. 6 is a diagrammatic illustration of a strip cutting unit.

DETAILED DESCRIPTION OF EMBODIMENTS

[0040] Embodiments of the present disclosure will now be described by way of example only and with reference to the accompanying drawings.

[0041] Referring initially to FIGS. 1a and 1b, there is shown an aerosol generating article 1 for use with an aerosol generating device that comprises an induction heating system to inductively heat the aerosol generating article 1 and thereby generate an aerosol for inhalation by a user of the device. Such devices are known in the art and will not be described in further detail in this specification. The aerosol generating article 1 is elongate, having a distal end 11a and a proximal end (or mouth end) 11b, and is substantially cylindrical. The circular cross-section facilitates handling of the article 1 by a user and insertion of the article 1 into a cavity or heating compartment of an aerosol generating device.

[0042] The aerosol generating article 1 comprises an aerosol generating substrate 10 having first and second ends 10a, 10b and an inductively heatable susceptor 12. The aerosol generating substrate 10 and the inductively heatable susceptor 12 are positioned in, and enclosed by, a wrapper 14. The wrapper 14 comprises a material which is substantially non-electrically conductive and non-magnetically permeable. In the illustrated example, the wrapper 14 is a paper wrapper and may comprise cigarette paper.

[0043] The aerosol generating article 1 may have a total length, measured between the distal end 11a and the proximal (mouth) end 11b, between 30 mm and 100 mm, preferably between 50 mm and 70 mm, possibly approximately 55 mm. The aerosol generating substrate 10 may have a total length, measured between the first and second ends 10a, 10b, between 5 mm and 50 mm, preferably between 10 mm and 30 mm, possibly approximately 20 mm. The aerosol generating article 1 may have a diameter between 5 mm and 10 mm, preferably between 6 mm and 8 mm, possibly approximately 7 mm.

[0044] The aerosol generating substrate 10 comprises a plurality of elongate first strips 15 comprising an aerosol generating material. The plurality of elongate first strips 15 constitute aerosol generating strips 16 and are substantially oriented in a longitudinal direction of the aerosol generating article 1. The elongate first strips 15 are typically foldless in the longitudinal direction to ensure that the air flow route is not interrupted and that a uniform air flow through the article 1 can be achieved.

[0045] The inductively heatable susceptor 12 comprises a plurality of elongate second strips 13 comprising an inductively heatable susceptor material. The plurality of elongate second strips 13 constitute susceptor strips 18 and are also substantially oriented in the longitudinal direction of the aerosol generating article 1. The elongate second strips 13 are foldless in the longitudinal direction to prevent hot spots in the aerosol generating substrate 10.

[0046] The aerosol generating article 1 comprises a plurality of elongate third strips 17 (see FIG. 1b) comprising an aerosol generating material. The elongate third strips 17 also constitute aerosol generating strips 16 and are substantially oriented in the longitudinal direction of the aerosol generating article 1. The elongate third strips 17 have the same length as the elongate first strips 15, and thus the aerosol generating strips 16 within the aerosol generating article 1 all have the same length. The elongate second strips 13 are adhered to the elongate third strips 17, and the elongate second strips 13 and the elongate third strips 17 have the same width. In preferred embodiments, the elongate first strips 15 also have the same width as the elongate second strips 13 and the elongate third strips 17.

[0047] The elongate first strips 15, the elongate second strips 13 and the elongate third strips 17 are arranged to form a substantially rod-shaped aerosol generating article 1 and can be randomly distributed throughout the cross-section of the rod-shaped aerosol generating article 1 such that they have a plurality of different orientations within the cross-section of the aerosol generating article 1. Although not apparent from FIG. 1b, a sufficient number of elongate first strips 15 are provided to substantially fill the cross-section of the aerosol generating substrate 10, and it will be understood that a smaller number of elongate first strips 15 are shown merely for illustration purposes. It should also be noted that any suitable number of elongate second strips 13 can be positioned in the aerosol generating substrate 10, depending on the heating requirements. Each of the elongate second strips 13 is advantageously surrounded by elongate first strips 15 thereby ensuring that heat transfer to the elongate first strips 15 is maximised and that the likelihood of contact between the elongate second strips 13 is minimised.

[0048] As best seen in FIG. 1a, each of the plurality of elongate first strips 15 has a distal end 15a and each of the plurality of elongate second strips 13 has a distal end 13a. The distal ends 15a of the elongate first strips 15 form the first end 10a of the aerosol generating substrate 10 and, correspondingly, the distal end 11a of the aerosol generating article 1. The elongate second strips 13 are shorter than the elongate first strips 15 and the elongate third strips 17. The distal ends 13a of the elongate second strips 13 are positioned inwardly from the distal ends 15a of the elongate first strips 15. The distal ends 13a of the elongate second strips 13 are, therefore, not visible at the distal end 11a of the aerosol generating article 1.

[0049] The aerosol generating article 1 comprises a mouthpiece segment 20 positioned downstream of the aerosol generating substrate 10. The aerosol generating substrate 10 and the mouthpiece segment 20 are arranged in coaxial alignment inside the wrapper 14 to hold the components in position to form the rod-shaped aerosol generating article 1.

[0050] In the illustrated embodiment, the mouthpiece segment 20 comprises the following components arranged sequentially and in co-axial alignment in a downstream direction, in other words from the distal end 11a to the proximal (mouth) end 11b of the aerosol generating article 1: a cooling segment 22, a center hole segment 23 and a filter segment 24. The cooling segment 22 comprises a hollow paper tube 22a having a thickness which is greater than the thickness of the paper wrapper 14. The center hole segment 23 may comprise a cured mixture containing cellulose acetate fibres and a plasticizer, and functions to increase the strength of the mouthpiece segment 20. The filter segment 24 typically comprises cellulose acetate fibres and acts as a mouthpiece filter. As heated vapour flows from the aerosol generating substrate 10 towards the proximal (mouth) end 11b of the aerosol generating article 1, the vapour cools and condenses as it passes through the cooling segment 22 and the center hole segment 23 to form an aerosol with suitable characteristics for inhalation by a user through the filter segment 24.

[0051] The elongate first strips 15 and elongate third strips 17 typically comprise plant derived material, such as tobacco. The elongate first strips 15 and elongate third strips 17 can advantageously comprise reconstituted tobacco including tobacco and any one or more of cellulose fibres, tobacco stalk fibres and inorganic fillers such as CaCO3.

[0052] The elongate first strips 15 and elongate third strips 17 typically comprise an aerosol-former such as glycerine or propylene glycol. Typically, the elongate first strips 15 and elongate third strips 17 comprise an aerosol-former content of between approximately 5% and approximately 50% on a dry weight basis. Upon heating, the elongate first strips and elongate third strips 17 release volatile compounds possibly including nicotine or flavour compounds such as tobacco flavouring.

[0053] When a time varying electromagnetic field is applied in the vicinity of the elongate second strips 13 during use of the article 1 in an aerosol generating device, heat is generated in the elongate second strips 13 due to eddy currents and magnetic hysteresis losses. The heat is transferred from the elongate second strips 13 to the elongate first strips 15 and elongate third strips 17 to heat the elongate first strips 15 and elongate third strips 17 without burning them to release one or more volatile compounds and thereby generate a vapour. As a user inhales through the filter segment 24, the heated vapour is drawn in a downstream direction through the article 1 from the first end 10a of the aerosol generating substrate 10 towards the second end 10b of the aerosol generating substrate 10, and towards the filter segment 24. As noted above, as the heated vapour flows through the cooling segment 22 and the center hole segment 23 towards the filter segment 24, the heated vapour cools and condenses to form an aerosol with suitable characteristics for inhalation by a user through the filter segment 24.

[0054] Manufacture of Aerosol Generating Articles Apparatus 30 and methods suitable for manufacturing aerosol generating articles according to the present disclosure, such as the aerosol generating article 1 described above with reference to FIGS. 1a and 1b, will now be described.

[0055] Referring to FIG. 2a, there is shown a diagrammatic illustration of an apparatus 30 and method for manufacturing the aerosol generating article 1 described above with reference to FIGS. 1a and 1b. FIG. 2b is a plan view of an aerosol generating substrate 10 and susceptor patches 28 as they move through the apparatus 30, in the direction of the arrow in FIG. 2b.

[0056] The apparatus 30 comprises a substrate supply reel 32 (e.g. a first bobbin) which carries a continuous web 34 of an aerosol generating substrate 10 having a substantially flat surface and first feed rollers 36 for controlling the feed of the continuous web 34 of aerosol generating substrate 10. The apparatus 30 may also include a web tension regulator and a web edge control system as will be understood by one of ordinary skill in the art, but these additional components are not essential in the context of the present disclosure and have, therefore, been omitted for the sake of simplicity.

[0057] The apparatus 30 comprises a susceptor supply reel 38 (e.g. a second bobbin) which carries a continuous web 40 of susceptor material, feed rollers 42, 44 for controlling the feed of the continuous web 40 of susceptor material, an adhesive applicator unit 46, and a susceptor cutting unit 48.

[0058] The apparatus 30 further comprises an optional heater 50, a strip cutting unit 52, feed rollers 54, a rod forming unit 56, and a rod cutting unit 58.

[0059] Susceptor Patch Preparation

[0060] In operation, a continuous web 34 of aerosol generating substrate 10 is continuously supplied from the substrate supply reel 32. At the same time, a continuous web 40 of susceptor material is continuously supplied from the susceptor supply reel 38, via the feed rollers 42, 44, to the adhesive applicator unit 46. The adhesive applicator unit 46 applies an adhesive 47 to a surface of the continuous web 40 of susceptor material. In the illustrated example, the adhesive applicator unit 46 applies the adhesive 47 to the surface of the continuous web 40 of susceptor material intermittently, and across the full width of the web 40. In this way, discrete adhesive areas 60 (see FIGS. 3 and 4) are formed on the surface of the continuous web 40 of susceptor material, with adhesive-free areas 62 being formed between adjacent adhesive areas 60 in the direction of travel of the continuous web 40 of susceptor material.

[0061] The continuous web 40 of susceptor material is supplied from the adhesive applicator unit 46 to the susceptor cutting unit 48 which continuously cuts the continuous web 40 of susceptor material to form a plurality of susceptor patches 28. As best seen in FIG. 2b, the continuous web 40 of susceptor material, and hence the susceptor patches 28, have a width which is substantially less than a width of the continuous web 34 of aerosol generating substrate 10. For example, the continuous web 34 of aerosol generating substrate 10 can have a width of approximately 140 mm whereas the continuous web of susceptor material, and hence the susceptor patches 28, can have a width of between approximately 0.1 mm and 5 mm. In some embodiments, the susceptor patches 28 can have a length of between approximately 5 mm and 50 mm in the direction of travel of the continuous web 40 of susceptor material and can have a thickness of between approximately 1 μm and 500 μm.

[0062] In order to minimise soiling of the susceptor cutting unit 48 by the adhesive 47 applied to the continuous web 40 of susceptor material by the adhesive applicator unit 46, the susceptor cutting unit 48 cuts the continuous web 40 of susceptor material in the adhesive-free areas 62, that is at positions between the adhesive areas 60 on the surface of the continuous web 40 of susceptor material. This can be achieved by synchronising the operation of the susceptor cutting unit 48 with the movement of the continuous web of susceptor material.

[0063] Referring to FIG. 5, the susceptor cutting unit 48 comprises a rotary cutting unit 64 comprising a support drum 66 and a cutting drum 68. The support drum 66 supports the continuous web 40 of susceptor material around its periphery and includes a plurality of circumferentially spaced recesses 70 around its periphery. The support drum 66 is typically a suction drum and the continuous web 40 of susceptor material and susceptor patches 28 are supported around the periphery of the suction drum by a suction force applied through suction ports 67. The cutting drum 68 includes a plurality of circumferentially spaced cutting elements 72, for example projecting cutting blades, around its periphery and the cutting elements 72 cooperate with (e.g., extend into) the circumferentially spaced recesses 70 during synchronised rotation of both the support drum 66 and the cutting drum 68 in opposite directions as shown by the arrows in FIG. 5. This results in continuous shear cutting of the continuous web 40 of susceptor material to form a plurality of susceptor patches 28.

[0064] Susceptor Patch Application

[0065] The susceptor patches 28 provided by the susceptor cutting unit 48 can be applied to the surface of the continuous web 34 of aerosol generating substrate 10 so that there is a constant and predetermined spacing 74 between the edges of each successive susceptor patch 28, for example as shown in FIGS. 2b and 4. The constant and predetermined spacing 74 may, for example, be between 1 mm and 20 mm. In order to generate the constant and predetermined spacing 74 between the edges of adjacent susceptor patches 28, the susceptor cutting unit 48 permits relative movement between the continuous web 40 of susceptor material and the support drum 66 for a predetermined period of time immediately after the continuous web 40 of susceptor material carried by the support drum 66 has been cut by the cutting drum 68 to form a susceptor patch 28. This relative movement allows the continuous web 40 of susceptor material to remain stationary or to travel at a reduced speed for a short period of time after a susceptor patch 28 has been cut from the continuous web 40 of susceptor material. The relative movement between the continuous web 40 of susceptor material and the support drum 66 can be achieved by, for example, reducing the suction force applied to the continuous web 40 of susceptor material by the support drum 66, whilst at the same time maintaining an adequate suction force between the already cut susceptor patches 28 and the support drum 66 to ensure that there is no relative movement between the susceptor patches 28 and the support drum 66. In this way, a susceptor patch 28 that has been cut from the continuous web 40 of susceptor material by the susceptor cutting unit 48 is conveyed for a short period of time at a greater speed than the continuous web 40 of susceptor material from which the susceptor patch 28 has been cut, thereby generating the desired constant and predetermined spacing 74 between the edges of adjacent susceptor patches 28.

[0066] The susceptor patches 28 with the adhesive 47 applied thereto are continuously and consecutively adhered to the surface of the continuous web 34 of aerosol generating substrate 10 substantially along a centre line of the continuous web 34. Adjacent susceptor patches 28 are spaced apart in the direction of travel of the continuous web 34 of aerosol generating substrate by the constant and predetermined spacing 74 between the edges of the susceptor patches 28 that is generated when the susceptor patches 28 are formed in the susceptor cutting unit 48. In order to ensure that there is adequate adhesion between the susceptor patches 28 and the substantially flat surface of the continuous web 34 of aerosol generating substrate 10, the susceptor patches 28 can be pressed onto the substantially flat surface by a cam roller 76, shown diagrammatically in FIG. 2a. The rotation of the cam roller 76 is synchronized with the movement of the continuous web 34 of aerosol generating substrate 10 so that a pressing force is applied to consecutive susceptor patches 28, but not to the spaced regions between consecutive susceptor patches 28.

[0067] Depending on the properties of the adhesive 47 applied to the continuous web 40 of susceptor material (and hence to the susceptor patches 28) by the adhesive applicator unit 46, the continuous web 34 of aerosol generating substrate 10 and the susceptor patches 28 adhered to the surface thereof can be heated by the optional heater 50. This may help to cure or set the adhesive 47, and thereby ensure a good bond between each susceptor patch 28 and the surface of the continuous web 34 of aerosol generating substrate 10. The heating temperature must be carefully selected based on the characteristics of both the aerosol generating substrate 10 and the adhesive 47, to ensure that sufficient heating is achieved to cure or set the adhesive 47, whilst at the same time avoiding or at least minimising the release of volatile components from the aerosol generating substrate 10.

[0068] Strip Cutting

[0069] The continuous web 34 of aerosol generating substrate 10 with the spaced susceptor patches 28 adhered to its surface is fed to the strip cutting unit 52 (best seen in FIG. 6) which simultaneously cuts the continuous web 34 of aerosol generating substrate 10 and the susceptor patches 28 to form a plurality of continuous aerosol generating strips 16 and a plurality of susceptor strips 18. In an embodiment, the strip cutting unit 52 cuts the continuous web 34 of aerosol generating substrate 10 and the susceptor patches 28 to form aerosol generating strips 16 and susceptor strips 18 having a strip width of approximately 1 mm. Thus, if the susceptor patches 28 have a width of 5 mm as discussed above, it will be understood that five susceptor strips 18 are formed by cutting each susceptor patch 28.

[0070] The ends of the susceptor strips 18 formed by cutting the susceptor patches 28 are longitudinally spaced by the same predetermined and constant spacing 74 that was present between the edges of adjacent susceptor patches 28. As shown in FIGS. 2a and 6, the strip cutting unit 52 is a rotary cutter unit 78 and comprises first and second cutting drums 80, 82. The first cutting drum 80 includes circumferentially extending first cutting formations 84 and the second cutting drum 82 includes circumferentially extending second cutting formations 86. The first and second cutting formations 84, 86 cooperate (e.g., intermesh) to shear cut the continuous web 34 of aerosol generating substrate 10 and the susceptor patches 28 in the direction of travel of the continuous web 34 to form the plurality of aerosol generating strips 16 and the plurality of susceptor strips 18. As will be appreciated from FIGS. 2b and 6, the aerosol generating strips 16 formed by cutting the central region of the continuous web 34 of aerosol generating substrate 10 with susceptor patches 28 adhered to its surface have susceptor strips 18 (i.e., elongate second strips 13) adhered to them, and it is the aerosol generating strips 16 formed by cutting this central region that constitute the elongate third strips 17. On the other hand, the aerosol generating strips 16 formed by cutting the side regions of the continuous web 34 of aerosol generating substrate 10, on opposite sides of the susceptor patches 28, do not have susceptor strips 18 adhered to them and it is the aerosol generating strips 16 formed by cutting these side regions that constitute the elongate first strips 15.

[0071] Rod Formation

[0072] The aerosol generating strips 16 and the susceptor strips 18 are conveyed to the rod forming unit 56 where they are formed into a continuous rod 88. If desired, a continuous sheet of wrapping paper (not shown) can be supplied to the rod forming unit 56 from a supply reel (not shown) or can be supplied to a separate wrapping unit (again from a supply reel) which can be positioned downstream of the rod forming unit 56. As the sheet of wrapping paper is transported and guided through the rod forming unit 56 or the separate wrapping unit, it can be wrapped around the aerosol generating strips 16 and the susceptor strips 18 so that the continuous rod 88 is circumscribed by a wrapper 14.

[0073] Rod Cutting

[0074] The continuous rod 88 (optionally circumscribed by a wrapper 14) is then transported to the rod cutting unit 58 where it is cut at appropriate positions into predetermined lengths to form multiple aerosol generating articles 1. The aerosol generating articles 1 formed by the rod cutting unit 58 may have a length between 5 mm and 50 mm, preferably between 10 mm and 30 mm. It will be understood that this length corresponds to the length of the aerosol generating substrate 10 described above with reference to FIGS. 1a and 1b. The continuous rod 88 is preferably cut repeatedly by the rod cutting unit 58 substantially at a midpoint between the ends of the susceptor strips 18 formed by cutting consecutive susceptor patches 28. In this way, the susceptor strips 18 are not cut by the rod cutting unit 58, thereby reducing wear on the cutting elements. Further, because the susceptor strips 18 are shorter than the aerosol generating strips 16, the ends of the susceptor strips 18 are not visible at either end of the aerosol generating articles 1 formed by the rod cutting unit 58. It will be understood that this type of method is particularly suitable for the mass production of aerosol generating articles 1.

[0075] Final Assembly

[0076] Further units (not shown) may be arranged downstream of the rod cutting unit 58 and may be configured to provide one or more additional components such as the mouthpiece segment 20 described above and to assemble these with the individual aerosol generating articles 1 formed by the rod cutting unit 56 to form finished aerosol generating articles 1, for example of the type illustrated in FIG. 1. In this case, a separate wrapping unit may be provided downstream of the rod cutting unit 58 so that the assembled components can be simultaneously wrapped to form the finished aerosol generating articles 1. The further units may form part of the apparatus 30 or may be separate, stand-alone, units forming part of a final assembly line.

[0077] Although exemplary embodiments have been described in the preceding paragraphs, it should be understood that various modifications may be made to those embodiments without departing from the scope of the appended claims. Thus, the breadth and scope of the claims should not be limited to the above-described exemplary embodiments.

[0078] Any combination of the above-described features in all possible variations thereof is encompassed by the present disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.

[0079] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like, are to be construed in an inclusive as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.