Abstract
A method of applying a coating to an aerosol generating assembly (1). The method comprises the steps of: providing an aerosol generating assembly (1) comprising a combustible heat source (2), an aerosol forming substrate (3), and a wrapper (4) joining the combustible heat source (2) and the aerosol forming substrate (3), the combustible heat source (2) having a downstream portion (22) circumscribed by the wrapper, and an upstream portion (21) not circumscribed by the wrapper; and applying, in a first application step, a coating formulation (6) from at least one applicator head (10, 14) onto the upstream portion (21) while rotating the aerosol generating assembly (1) about its longitudinal axis (9).
Claims
1-14. (canceled)
15. A method of applying a coating to an aerosol generating assembly, the method comprising the steps of: providing an aerosol generating assembly, the aerosol generating assembly comprising a combustible heat source, an aerosol forming substrate and a wrapper joining the combustible heat source and the aerosol forming substrate, the combustible heat source having a downstream portion circumscribed by the wrapper and an upstream portion not circumscribed by the wrapper; and applying, in a first application step, a coating formulation from at least one applicator head onto the upstream portion of the combustible heat source while rotating the aerosol generating assembly about its longitudinal axis.
16. A method according to claim 15, wherein the at least one applicator head comprises at least one rolling hand which, in the first application step, applies the coating formulation onto the upstream portion of the combustible heat source by coming into contact with the upstream portion of the combustible heat source.
17. A method according to claim 15, wherein the at least one applicator head comprises at least one spray nozzle which, in the first application step, sprays the coating formulation onto the upstream portion of the combustible heat source.
18. A method according to claim 15, further comprising providing a front face mask between the at least one applicator head and a front face of the combustible heat source such that the coating formulation is not applied onto the front face during the first application step.
19. A method according to claim 15, further comprising providing a wrapper mask between the at least one applicator head and the wrapper such that the coating formulation is not applied onto the wrapper during the first application step.
20. A method according to claim 19, wherein the wrapper mask is arranged at between about 30 degrees and about 90 degrees from the longitudinal axis of the aerosol generating assembly.
21. A method according to claim 19, wherein the wrapper mask comprises at least one channel to direct coating formulation which collects on it to a specific location.
22. A method according to claim 15, wherein during the first application step, the aerosol generating assembly is rotated between a transport drum and an external roller.
23. A method according to claim 15, further comprising a first drying step performed after the first application step.
24. A method according to claim 15, further comprising a second application step after the first application step in which a coating formulation is applied from at least one applicator head onto the upstream portion of the combustible heat source while rotating the aerosol generating assembly about its longitudinal axis.
25. A method according to claims 23, wherein the first drying step occurs between the first application step and the second application step.
26. An apparatus for applying a coating to an aerosol generating assembly, the apparatus comprising a rotator for holding and rotating an aerosol generating assembly, at least one applicator head arranged to apply a coating formulation onto an upstream portion of the aerosol generating assembly while the rotator rotates the aerosol generating assembly around its longitudinal axis, a wrapper mask and a front face mask configured in such a way that the coating formulation is only applied onto the upstream portion of the aerosol generating assembly, and at least one drying drum configured to dry the coating formulation once applied onto the upstream portion of the aerosol generating assembly.
27. The apparatus according to claim 26, wherein the rotator further comprises a transport drum and an external roller to rotate the aerosol generating assembly around its longitudinal axis.
Description
[0142] These and other features and advantages of the invention will become more evident in the light of the following detailed description of preferred embodiments, given only by way of illustrative and non-limiting example, in reference to the attached figures:
[0143] FIG. 1 shows an aerosol generating assembly.
[0144] FIG. 2 illustrates an application step to apply a coating formulation to an upstream portion of a combustible heat source of the aerosol generating assembly using a spray nozzle.
[0145] FIG. 3 depicts an external roller and a transport drum to rotate the aerosol generating assembly around its longitudinal axis during the application step of FIG. 2.
[0146] FIG. 4 represents a drying step performed after the application step in which drying drums are used.
[0147] FIG. 5 illustrates an application step to apply a coating formulation to an upstream portion of a combustible heat source of the aerosol generating assembly using a rolling hand.
[0148] FIG. 6 depicts the rolling hand and a transport drum to rotate the aerosol generating assembly around its longitudinal axis during the application step of FIG. 5.
[0149] The aerosol generating assembly 1 of the embodiment of FIG. 1 comprises two combustible heat sources 2 and an aerosol forming substrate 3 between the combustible heat sources 2, located downstream of both combustible heat sources 2. Each combustible heat source 2 comprises a front face 5 on its upstream end and a rear face 7 on its downstream end. The front faces 5 constitute the upstream end of the aerosol generating assembly 1, whereas the middle cross section of the aerosol forming substrate 3 corresponds to the downstream end of the aerosol generating assembly 1. The aerosol forming substrate 3 and the combustible heat sources 2 are joined by a wrapper 4 disposed around the aerosol generating assembly 1 in such a way that it circumscribes aerosol forming substrate 3 and it partially circumscribes the heat sources 2. Hence, the heat sources 2 comprise an upstream portion 21 not circumscribed by the wrapper 4 and a downstream portion 22 circumscribed by the wrapper 4.
[0150] The aerosol generating assembly of FIG. 1 can give rise to two aerosol generating articles. In an embodiment, the aerosol generating assembly can be cut into two symmetrical subassemblies. The resulting subassemblies extend longitudinally from a downstream end which corresponds to the middle cross section along which the aerosol generating assembly 1 is cut and an upstream end corresponding to the front face 5.
[0151] Although not represented in FIG. 1, the aerosol generating assembly of this embodiment may also comprise other components, such as a spacer element, an aerosol cooling element, a filter or a mouthpiece. Likewise, the subassemblies generated from the aerosol generating assembly may also be provided with these components when generating the aerosol generating articles.
[0152] FIG. 2 represents a method of applying a coating to the aerosol generating assembly 1 of FIG. 1, by means of a spray nozzle 10.
[0153] An apparatus for applying the coating is provided, the apparatus comprising the spray nozzle 10 and a rotator (not represented in FIG. 2) for rotating the aerosol generating assembly 1 around its longitudinal axis 9, as indicated by arrow 8.
[0154] The spray nozzle 10 sprays a coating formulation 6 onto the upstream portion 21 of the combustible heat source 2.
[0155] In the embodiment of FIG. 2, the spray nozzle 10 is directed about 90 degrees towards the longitudinal axis 9 of the aerosol generating assembly 1, in order to provide a consistent coating.
[0156] The apparatus of FIG. 1 also comprises a wrapper mask 11, arranged between the spray nozzle 10 and the wrapper 4 such that the coating formulation 6 is not applied onto the wrapper 4 during the application step. The wrapper mask 11 is arranged at about 75 degrees from the longitudinal axis 9 of the aerosol generating assembly 1. This angle permits to recuperate and reuse the coating formulation 6 received on the wrapper mask 11, by means of a channel 13.
[0157] The apparatus of FIG. 1 also comprises a front face mask 12, arranged between the spray nozzle 10 and the front face 5 of the combustible heat source 5 such that the coating formulation 6 is not applied onto the front face 5 during the application step. In addition or alternatively to the provision of the front face mask 12, the spray nozzle 10 may be directed towards the longitudinal axis 9 with an angle between about 45 degrees and about 90 degrees.
[0158] FIG. 3 represents the rotator 30 of the apparatus of FIG. 2. The rotator 30 comprises a transport drum 31 and an external roller 32. The transport drum 31 and an the external roller 32 can rotate in clockwise direction to provide the aerosol generating assembly 1 disposed between the transport drum 31 and the external roller 32 with a rotational movement around its longitudinal axis 9. The transport drum 31 of FIG. 3 comprises a first groove 310 and a second groove 311, which are configured to hold the aerosol generating assembly 1. In an example, suction air is provided to hold the aerosol generating assembly 1 in the first groove 310 or in the second groove 311. When the external roller 32 comes into contact with the aerosol generating assembly 1 held in a groove, such as the first groove 310, the assembly 1 is lifted out of the first groove 310 and forced to rotate around its longitudinal axis 9—during such rotation, the spray nozzle 10 (not represented in FIG. 3) applies the coating formulation 6 to the upstream portion 21 of the combustible heat source 2. The aerosol generating assembly 1 rolls between the transport drum 31 and the external roller 32 until it falls into the second groove 311. Then, the aerosol generating assembly 1 is moved away from the external roller 32.
[0159] The distance along the perimeter of the transport drum 31 between the first groove 310 and the second groove 311 determines how many rotations the aerosol generating assembly 1 will do between the first groove 310 and the second groove 311. For example, the distance may be adjusted so the aerosol generating assembly 1 rotates 2, 3, 4, 5, or more times, applying at least one layer of coating formulation 6 each time. The number of layers applied may depend on the desired thickens of the coating and various properties of the coating formulation 6, for example, the viscosity of the coating formulation 6.
[0160] Once the aerosol generating assembly 1 moves away from the external roller 32, the method of this embodiment comprises a drying step performed after the application step shown in FIGS. 2 and 3. The drying step is represented in FIG. 4. FIG. 4 shows the path followed by a plurality of aerosol generating assemblies 1 after moving past the external roller 32. The aerosol generating assemblies 1 held in the second groove 311, third groove 312 and subsequent grooves 313, 314 of the transport drum 31 will be sequentially transferred to a 20.09 40 adjacent the transport drum 31 and rotating in an opposite direction to that of the transport drum 31. In this embodiment, the drying 40 drum may also comprise drying grooves 401, 402, 403, etc. to hold the aerosol generating assemblies 1 during their rotation on the drying drum 40. In this embodiment, a plurality of drying drums 40 is provided, adjacent to each other in such a way that adjacent drying drums 40 rotate in opposite directions to facilitate the transfers of the aerosol generating assemblies 1 as explained for the transfer between the transport drum 31 and the first drying drum 40. The duration of the drying step therefore depends on the number, size, and speed of the drying drums 40 and may be adapted depending on the characteristics of the coating formulation 6. The drying step of FIG. 4 is enhanced by the provision of hot air 41 and infrared radiation 42 in the area through which the aerosol generating assemblies 1 are transported by the drying drums 40.
[0161] FIG. 5 represents an embodiment of the method of applying the coating to the aerosol generating assembly 1 of FIG. 1.
[0162] Differently to the embodiment of FIG. 2, the apparatus comprises, instead of the spray nozzle 10, a rolling hand 14 which, in this embodiment, comprises a sponge-like material. The sponge-like material 14 is impregnated with coating formulation 6 such that the sponge-like material 14 oozes out the coating formulation 6 onto the upstream portion 21 of the combustible heat source 2 when the rolling hand 14 comes into contact with the upstream portion 21, as represented in FIG. 5.
[0163] FIG. 6 represents the rotator 30 of the apparatus of FIG. 5. The rotator 30 comprises a transport drum 31 similar to that of FIG. 3 and the rolling hand 14. The relative movement between the transport drum 31 and the rolling hand 14 provides the aerosol generating assembly 1 disposed between the transport drum 31 and the rolling hand 14 with a rotational movement around its longitudinal axis 9. When the rolling hand 14 comes into contact with the aerosol generating assembly 1 held in a groove, such as the first groove 310, the assembly 1 is lifted out of the first groove 310 and forced to rotate around its longitudinal axis 9—during such rotation, the sponge-like material of the rolling hand 14 applies the coating formulation 6 to the upstream portion 21 of the combustible heat source 2 by oozing out the coating formulation 6 onto the upstream portion 21. The aerosol generating assembly 1 rolls between the transport drum 31 and the rolling hand 14 until it falls into the second groove 311. Then, the aerosol generating assembly 1 is moved away from the rolling hand 14.
[0164] Except in the features set out above, the embodiment of FIGS. 5 and 6 is similar to that of FIGS. 2 and 3. The common features are not described again here for the sake of conciseness. Likewise, in the embodiment of FIGS. 5 and 6, once the aerosol generating assembly 1 moves away from the rolling hand 14, the method of this embodiment comprises a drying step performed as illustrated in FIG. 4 and described above.
