Abstract
The invention relates to a mouthpiece (10) for an aerosol-generating device. The mouthpiece (10) comprises an inlet portion (12) configured for receiving an aerosol and an outlet portion (14) configured for outflow of the aerosol. An airflow path (16) connects the inlet portion (12) and the outlet portion (14). The airflow path (16) comprises an inner wall (18). The inner wall (18) of the airflow path (16) is at least partially lined with a capillary material (20). The capillarity of the capillary material (20) increases towards the inlet portion (12).
Claims
1. A mouthpiece for an aerosol-generating device, wherein the mouthpiece comprises: an inlet portion configured for receiving an aerosol, an outlet portion configured for outflow of the aerosol, and an airflow path connecting the inlet portion and the outlet portion, wherein the airflow path comprises an inner wall, wherein the inner wall of the airflow path is at least partially lined with a capillary material, wherein the capillarity of the capillary material increases towards the inlet portion and wherein the capillary material is a woven fiber tube.
2. (canceled)
3. The mouthpiece according to claim 1, wherein the fiber density of the woven fiber tube increases towards the inlet portion.
4. The mouthpiece according to claim 1, wherein the capillary material lines the full circumference of the inner wall of the airflow path.
5. The mouthpiece according to claim 1, wherein the diameter of the airflow path at the outlet portion is greater than the diameter of the airflow path at the inlet portion.
6. The mouthpiece according to claim 1, wherein the airflow path has a conical shape, and wherein the diameter of the airflow path at the outlet portion is greater than the diameter of the airflow path at the inlet portion.
7. The mouthpiece according to claim 1, wherein the capillary material is configured as a coating coated onto the inner wall of the airflow path.
8. The mouthpiece according to claim 1, wherein a surface energy increasing coating is provided on the inner wall of the airflow path or the capillary material or the inner wall of the airflow path and the capillary material.
9. The mouthpiece according to claim 1, wherein the capillary material is made of one or more of ceramic, carbon, fabric or plastic.
10. An aerosol-generating device, wherein the aerosol-generating device comprises: a main body comprising: an air inlet configured to allow ambient air to be drawn into the device, a liquid storage portion for holding liquid aerosol-forming substrate, and a heating chamber with an atomizer for generating an inhalable aerosol, a mouthpiece according to claim 1, wherein the mouthpiece is configured attached or attachable to the main body.
11. A method for manufacturing a mouthpiece for an aerosol-generating device, wherein the method comprises the following steps: i. providing a mouthpiece comprising an inlet portion configured for receiving an aerosol, an outlet portion configured for outflow of the, and an airflow path connecting the inlet portion and the outlet portion, wherein the airflow path comprises an inner wall, ii. at least partially lining the inner wall of the airflow path with a capillary material, wherein the capillarity of the capillary material increases towards the inlet portion and wherein the capillary material is a woven fiber tube.
Description
[0044] The invention will be further described, by way of example only, with reference to the accompanying drawings in which:
[0045] FIG. 1 shows an illustrative cross-sectional view of an embodiment of a mouthpiece according to the present invention,
[0046] FIG. 2 shows an illustrative cross-sectional view of a further embodiment of the mouthpiece according to the present invention,
[0047] FIG. 3 shows an illustrative view of a woven fiber tube used as capillary material in the mouthpiece according to the present invention, and
[0048] FIG. 4 shows an illustrative cross-sectional view of an embodiment of an aerosol-generating device according to the present invention,
[0049] FIG. 1 shows a mouthpiece 10 according to the present invention for an aerosol-generating device. The mouthpiece 10 comprises an inlet portion 12. The inlet portion 12 is configured to allow an aerosol to enter the mouthpiece 10. The inlet portion 12 is preferably configured as an opening for this purpose. The inlet portion 12 is arranged at an upstream or distal end of the mouthpiece 10. An outlet portion 14 is provided opposite the inlet portionl2. The outlet portion 14 may be a mouth-end of the mouthpiece 10, which may be in contact with the lips of a user for aerosol inhalation. The outlet portion 14 is configured to enable outflow of aerosol out of the mouthpiece 10. The outlet portion 14 is arranged at the downstream end of the mouthpiece 10. The outlet portion 14 is preferably arranged at the proximal end of the mouthpiece 10.
[0050] FIG. 1 further shows an airflow channel 16 arranged between the inlet portion 12 and the outlet portion 14. The airflow channel 16 allows airflow, particularly flow of aerosol, between the inlet portion 12 and the outlet portion 14. The airflow channel 16 in the embodiment shown in FIG. 1 has a hollow tubular shape. The cross-section of the airflow channel 16 is preferably circular. The airflow channel 16 thus preferably has a cylindrical shape. The airflow channel 16 has an inner wall 18 facing the inside of the airflow channel 16. The inner wall 18 is arranged around the longitudinal axis of the mouthpiece 10. The longitudinal axis of the mouthpiece 10 may be identical to the longitudinal axis of the airflow channel 16. The airflow channel 16 may also be offset with respect to the longitudinal axis of the mouthpiece 10.
[0051] The inner wall 18 of the airflow channel 16 is lined with capillary material 20. The capillary material 20 shown in FIG. 1 lines the complete circumference of the airflow channel 16. In other words, the whole inner wall 18 of the airflow channel is lined with the capillary material 20 in the embodiment shown in FIG. 1. However, only parts of the inner wall 18 of the airflow channel 16 may be lined with the capillary material 20, if desirable. For example, it may not be necessary to line the whole inner wall 18 with capillary material 20 to achieve a desired degree of condensation entrainment. The capillary material 20 is configured to entrain liquid droplets formed in the aerosol passing through the airflow channel 16, which come into contact with the capillary material 20. The droplets may be soaked by the capillary material 20. In addition, the entrained liquid may be transported through the capillary material 20 by capillary action. The capillary material 20 is preferably provided as a woven fiber tube, which can be optimally inserted into the airflow channel 16 for lining the inner wall 18 of the airflow channel 16.
[0052] The capillarity of the capillary material 20 increases in the direction of the inlet portion 12. Thus, condensed liquid droplets of aerosol-forming substrate may be wicked by the capillary material 20 in the direction of the inlet portion 12. The increased capillarity of the capillary material 20 in the area of the inlet portion 12 may create a suction effect for liquid aerosol-forming substrate farther away from the inlet portion 12 so that the liquid is drawn towards the inlet portion 12.
[0053] FIG. 2 shows a further embodiment, in which the airflow channel 16 has a conical shape, with the airflow channel 16 tapering in the direction of the inlet portion 12. The conical shape of the airflow channel 16 may aid wicking of entrained liquid away from the outlet portion 14 to prevent leakage of the liquid. In this regard, the capillary material 20 lining the inner wall 18 of the airflow channel 16 adjacent to the inlet portion 12 may be compressed in radical direction more than that adjacent to the outlet portion 14 thereby increasing the density of the capillary material 20 towards the inlet portion 12. Increased density of the capillary material 20 may increase capillarity of the capillary material 20.
[0054] FIG. 3 shows an example of the capillary material 20 in the form of a woven fibre tube. The capillary material 20 is preferably inserted into the airflow channel 16 and may be treated to line the inner wall 18 of the airflow channel 16. Treatments such as heating the woven fiber tube after insertion into the airflow channel 16 may be employed to bond the woven fiber tube to the inner wall 18 of the airflow channel 16. The woven fiber tube may be flexible such that the woven fiber tube may adapt to the shape of the airflow channel 16. If the woven fiber tube is inserted into a conical airflow channel 16 as shown in FIG. 2, the woven fiber tube comprising the capillary material 20 will also have a conical shape. In this this case, the fiber density of the capillary material 20 will increase towards the inlet portion 12 thereby increasing capillarity towards the inlet portion 12.
[0055] FIG. 4 shows an aerosol-generating device with a mouthpiece 10 as described above and a main body 22. The mouthpiece 10 is attached or attachable to the main body 22. The main body 22 preferably comprises a heating chamber 24, wherein a vaporiser is arranged in or around the heating chamber 24 for generation of an inhalable aerosol. The liquid aerosol-forming substrate which is used in the heating chamber 24 for aerosol generation may be stored in a liquid storage portion 26. The liquid storage portion 26 may be fixed to the main body 22 permanently or provided as a replaceable cartridge.
[0056] FIG. 4 also shows a power supply 28 such as a battery for powering the vaporiser. Electric circuitry 30 may control supply of electrical energy from the power supply 28 towards the vaporiser. An air inlet which is not shown in FIG. 4 allows ambient air to enter the device. The air flows from the air inlet towards the heating chamber 24 for aerosol generation. After the aerosol has been generated, the aerosol flows into the mouthpiece 10 by means of the inlet portion 12 of the mouthpiece 10. The aerosol continues to pass through the airflow channel 16 of the mouthpiece 10 and towards the outlet portion 14 of the mouthpiece for inhalation by a user. As described above, leakage of condensed aerosol-forming substrate is prevented by lining the inner wall 18 of the airflow channel 16 with capillary material 20. In addition, the capillary material 20 has a higher capillarity in the direction of the inlet portion 12 so that condensed liquid entrained by the capillary material 20 is predominantly wicked towards the inlet portion 12 by capillary action. This configuration of the capillary material 20 not only enhances leakage prevention of the condensed aerosol. This configuration of the capillary material 20 also enables channeling of the liquid aerosol-forming substrate back towards the heating chamber 24 of the aerosol-generating device. The condensed substrate may then be vaporized again in the heating chamber 24 so that usage of the aerosol-generating substrate is optimized.
