Aerosol-generating article having a cover layer

Abstract

An aerosol-generating article may include a base layer, at least one aerosol-forming substrate positioned on the base layer, and a cover layer overlying the at least one aerosol-forming substrate and secured to the base layer so that the at least one aerosol-forming substrate is sealed between the base layer and the cover layer. The cover layer includes a polymeric film comprising at least one of a plurality of micropores and a plurality of microperforations.

Claims

1. An aerosol-generating article comprising: a base layer; at least one aerosol-forming substrate positioned on the base layer; and a cover layer overlying the at least one aerosol-forming substrate and secured to the base layer such that the at least one aerosol-forming substrate is sealed between the base layer and the cover layer, the cover layer including a polymeric film defining at least one of a plurality of micropores and a plurality of microperforations.

2. The aerosol-generating article according to claim 1, wherein the plurality of micropores have a number average diameter of less than 2 nanometres at a temperature of 25 degree Celsius.

3. The aerosol-generating article according to claim 1, wherein the plurality of microperforations have a number average diameter of less than 100 micrometres at a temperature of 25 degrees Celsius.

4. The aerosol-generating article according to claim 1, wherein the polymeric film includes at least one of polypropylene, polyethylene, polytetrafluoroethylene, and combinations thereof.

5. The aerosol-generating article according to claim 1, wherein the base layer and the at least one aerosol-forming substrate are in contact with each other at a substantially planar contact surface.

6. The aerosol-generating article according to claim 1, wherein the base layer defines at least one cavity, and the at least one aerosol-forming substrate is positioned within the at least one cavity.

7. The aerosol-generating article according to claim 1, wherein the at least one aerosol-forming substrate is in a form of a plurality of aerosol-forming substrates arranged separately on the base layer.

8. The aerosol-generating article according claim 7, wherein the base layer defines a plurality of cavities, and each of the plurality of aerosol-forming substrates is positioned in one of the plurality of cavities.

9. The aerosol-generating article according to claim 1, wherein the at least one aerosol-forming substrate includes a first porous carrier material and a nicotine source sorbed onto the first porous carrier material.

10. The aerosol-generating article according to claim 9, wherein the at least one aerosol-forming substrate includes a first aerosol-forming substrate and a second aerosol-forming substrate, the first aerosol-forming substrate including the first porous carrier material and the nicotine source sorbed onto the first porous carrier material, the second aerosol-forming substrate including a second porous carrier material and an acid source sorbed onto the second porous carrier material.

11. The aerosol-generating article according to claim 1, wherein the at least one aerosol-forming substrate includes a tobacco-containing material provided on the base layer.

12. The aerosol-generating article according to claim 1, further comprising: at least one electric heater.

13. An aerosol-generating system comprising: an aerosol-generating device; at least one electric heater; and the aerosol-generating article according to claim 1, the aerosol-generating device including an electrical power supply and a controller configured to control a supply of electrical power from the electrical power supply to the at least one electric heater.

14. The aerosol-generating system according to claim 13, wherein the at least one electric heater and the aerosol-generating device is configured as an integral structure.

15. The aerosol-generating system according to claim 13, wherein the at least one electric heater and the aerosol-generating article is configured as an integral structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The various features and advantages of the non-limiting embodiments herein may become more apparent upon review of the detailed description in conjunction with the accompanying drawings. The accompanying drawings are merely provided for illustrative purposes and should not be interpreted to limit the scope of the claims. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. For purposes of clarity, various dimensions of the drawings may have been exaggerated.

(2) FIG. 1 shows a perspective view of an aerosol-generating article according to an example embodiment.

(3) FIG. 2 shows a perspective view of an aerosol-generating article according to another example embodiment.

(4) FIG. 3 shows a cross-sectional view of an aerosol-generating device for use with aerosol-generating articles according to an example embodiment.

(5) FIG. 4 shows a cross-sectional view of the aerosol-generating article of FIG. 2 combined with the aerosol-generating device of FIG. 3 to form an aerosol-generating system.

DETAILED DESCRIPTION

(6) It should be understood that when an element or layer is referred to as being “on,” “connected to,” “coupled to,” or “covering” another element or layer, it may be directly on, connected to, coupled to, or covering the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element or layer, there are no intervening elements or layers present. Like numbers refer to like elements throughout the specification. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

(7) It should be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or section from another region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of example embodiments.

(8) Spatially relative terms (e.g., “beneath,” “below,” “lower,” “above,” “upper,” and the like) may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It should be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” may encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

(9) The terminology used herein is for the purpose of describing various embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes,” “including,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

(10) Example embodiments are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of example embodiments. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, example embodiments should not be construed as limited to the shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing.

(11) Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, including those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

(12) FIG. 1 shows an aerosol-generating article 10 according to an example embodiment. The aerosol-generating article 10 comprises a base layer 12 and an aerosol-forming substrate 14 provided on the base layer 12. The aerosol-forming substrate 14 comprises a substantially continuous layer of a solid tobacco-containing material. A cover layer 16 is secured to the base layer 12 to seal the aerosol-forming substrate 14 between the base layer 12 and the cover layer 16. The cover layer 16 is formed from a microperforated polymeric film.

(13) Prior to use, the microperforated polymeric film forming the cover layer 16 is substantially impermeable to one or more volatile compounds in the aerosol-forming substrate 14. Therefore, prior to use, the one or more volatile compounds are sealed between the base layer 12 and the cover layer 16.

(14) During use, the aerosol-generating article 10 is heated so that the size of the microperforations in the polymeric film increases. The increased size of the microperforations when the aerosol-generating article is heated results in the cover layer 16 becoming permeable to one or more volatile compounds in the aerosol-forming substrate 14. Therefore, when the aerosol-generating article 10 is heated, one or more volatile compounds are released from the aerosol-forming substrate 14 through the cover layer 16.

(15) Instead of a microperforated cover layer 16, the cover layer may be formed from a microporous polymeric film, wherein the micropores provide the same temperature dependent permeability as the micrperforations. Alternatively, the cover layer 16 may be formed from a polymeric material comprising both micropores and microperforations.

(16) FIG. 2 shows an aerosol-generating article 20 according to an example embodiment. The aerosol-generating article 20 comprises a base layer 12 and a cover layer 16 identical to the base layer 12 and the cover layer 16 of the aerosol-generating article 10 shown in FIG. 1. In particular, the function of the cover layer 16 when at room temperature and when heated is the same as the cover layer 16 described with reference to FIG. 1.

(17) The aerosol-generating article 20 comprises a plurality of discrete aerosol-forming substrates 24 positioned on the base layer 12 and sealed between the base layer 12 and the cover layer 16. Each of the aerosol-forming substrates 24 comprises a porous carrier material and a liquid aerosol-forming substrate sorbed onto the porous carrier material.

(18) The plurality of aerosol-forming substrates 24 is divided into three groups: a plurality of first aerosol-forming substrates 28 each comprising a liquid nicotine solution; a plurality of second aerosol-forming substrates 30 each comprising a volatile acid; and a plurality of third aerosol-forming substrates 32 each comprising a flavourant.

(19) FIG. 3 shows a cross-sectional view of an aerosol-generating device 100 for use with the aerosol-generating articles according to an example embodiment. The aerosol-generating device 100 comprises a housing 112 defining a cavity 114 for receiving an aerosol-generating article. An air inlet 116 is provided at an upstream end of the cavity 114 and a mouthpiece 118 is provided at a downstream end of the housing 112. An air outlet 120 is provided in the mouthpiece 118 in fluidic communication with the cavity 114 so that an airflow path is defined through the cavity 114 between the air inlet 116 and the air outlet 120. During use, a negative pressure may be applied to the mouthpiece 118 to draw air into the cavity 114 through the air inlet 116 and out of the cavity 114 through the air outlet 120.

(20) The aerosol-generating device 100 further comprises a plurality of electric heaters 122 provided on a planar wall 124 of the cavity 114. Each of the electric heaters 122 comprises a heater element 126 provided on a common support layer 128.

(21) The aerosol-generating device 100 further comprises an electrical power supply 140 and a controller 142 positioned within the housing 112. During operation of the aerosol-generating device 100, the controller 142 controls a supply of electrical current from the electrical power supply 140 to each electric heater 122 to activate the each electric heater 122. The controller 142 may be configured to activate the plurality of electric heaters 122 in groups, with each group being activated and deactivated sequentially.

(22) FIG. 4 shows the aerosol-generating article 20 of FIG. 2 combined with the aerosol-generating device 100 of FIG. 3 to form an aerosol-generating system 200. During use, the aerosol-generating article 20 is inserted into the cavity 114 of the aerosol-generating device 100. The arrangement of the aerosol-forming substrates 24 is such that each aerosol-forming substrate 24 overlies an electric heater 122 when the aerosol-generating article 20 is received within the cavity 114.

(23) The controller 142 then sequentially activates and deactivates groups of the electric heaters 122 to sequentially heat the discrete aerosol-forming substrates 24. The heat from each activated electric heater 122 also heats the overlying portion of the cover layer 16 so that the microperforations in the heated portion of the cover layer 16 enlarge and become permeable to one or more volatile compounds in the heated aerosol-forming substrate 24.

(24) At each stage of the sequential activation, the controller 142 activates the appropriate electric heaters 122 to simultaneously heat one of the first aerosol-forming substrates 28, one of the second aerosol-forming substrates 30 and one of the third aerosol-forming substrates 32. The nicotine vapour released from the heated first aerosol-forming substrate 28 and the acid vapour released from the heated second aerosol-forming substrate 30 react in the gas phase to form an aerosol comprising nicotine salt particles for delivery through the air outlet 120. The flavourant released from the heated third aerosol-forming substrate 32 imparts a flavour to the aerosol.

(25) While a number of example embodiments have been disclosed herein, it should be understood that other variations may be possible. Such variations are not to be regarded as a departure from the spirit and scope of the present disclosure, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.