Aerosol generating device and method for controlling aerosol generation

Abstract

A method of controlling aerosol generation in an aerosol generating device, the method comprising: increasing the temperature of a heating element from an initial temperature to a first temperature, the first temperature being maintained constant for a first predetermined time period, the first temperature being between 180 and 230 degrees Celsius; adjusting the temperature of the heating element to a second temperature for a second predetermined time period, the second predetermined time period being immediately following the first predetermined time period, the second predetermined time period being longer than the first predetermined time period, and controlling power during heating of the aerosol-forming substrate to form an aerosol for inhalation by a user.

Description

[Technical field]

[0001] The present disclosure relates to a method of controlling aerosol generation in an aerosol generating device configured to heat an aerosol-generating article comprising a solid or gel aerosol-forming substrate, and also to an aerosol generating device and a system comprising the aerosol generating device and the aerosol-generating article. [Background technology]

[0002] The aerosol generating device may comprise an electrically operated heat source configured to heat an aerosol-generating article including an aerosol-forming substrate to generate an aerosol. Typically, in a heated aerosol-generating article, the aerosol is generated by the transfer of heat from the heat source to a physically separate aerosol-forming substrate. In use, volatile compounds are released from the aerosol-forming substrate by the transfer of heat from the heat source to the aerosol-forming substrate and are entrained in air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol that is inhaled by the user.

[0003] A number of handheld aerosol generating devices configured to heat an aerosol-forming substrate of a heated aerosol-generating article are known in the art. Such devices include electrically operated aerosol generating devices in which an aerosol is generated by heat transfer from one or more electric heating elements of the aerosol generating device to the aerosol-forming substrate of the heated aerosol-generating article. Known handheld electrically operated aerosol generating devices typically comprise a battery, control electronics, and one or more electric heating elements for heating the aerosol-forming substrate of the heated aerosol-generating article.

[0004] It would be desirable to provide an aerosol generating device and method for controlling aerosol production in an aerosol generating device, where a large amount of volatile compounds is delivered to the user from the first puff, and where good delivery of volatile compounds is maintained throughout the user experience. Summary of the Invention

[0005] According to one embodiment, there is provided a method for controlling aerosol generation in an aerosol generating device. The device comprises a heating chamber configured to at least partially receive an aerosol-generating article including an aerosol-forming substrate, a heating system comprising a heating element configured to externally heat the aerosol-forming substrate, and a power source for providing power to the heating system. The method comprises increasing the temperature of the heating element from an initial temperature to a first temperature, the first temperature being maintained constant for a first predetermined period of time, the first temperature being between 180 and 230 degrees Celsius, adjusting the temperature of the heating element to a second temperature for a second predetermined period of time, the second predetermined period of time being immediately following the first predetermined period of time, the second predetermined period of time being longer than the first predetermined period of time, and controlling the power during heating of the aerosol-forming substrate to form an aerosol for inhalation by a user.

[0006] By heating the heating element to a temperature within this range for a first predetermined period of time, the thermal inertia of the aerosol-forming substrate is overcome and the amount of desired volatile compounds vaporized in the aerosol inhaled by the user is improved from the first puff.

[0007] As used herein in connection with the present invention, the term "aerosol-generating device" is used to describe a device that interacts with an aerosol-forming substrate of an aerosol-generating article to generate an aerosol. The aerosol-generating device may be a hand-held, electrically operated device.

[0008] As used herein in connection with the present invention, the term "aerosol-generating article" is used to describe an article that includes an aerosol-forming substrate that is heated to generate and deliver an inhalable aerosol to a user. The aerosol-generating article may be disposable.

[0009] As used herein in connection with the invention, the term "aerosol" is used to describe a dispersion of solid particles, or liquid droplets, or a combination of solid particles and liquid droplets, in a gas. Aerosols can be visible or invisible. Aerosols may include not only vapors of substances that are normally liquids or solids at room temperature, but also solid particles or liquid droplets, or a combination of solid particles and liquid droplets.

[0010] As used herein in connection with the present invention, the term "aerosol-forming substrate" is used to describe a substrate that includes an aerosol-generating material that is capable of releasing, upon heating, a volatile compound capable of generating an aerosol.

[0011] The power source is preferably a battery, such as a lithium ion battery. Alternatively, the power source may be another form of charge storage device, such as a capacitor. The power source may require recharging. For example, the power source may have a capacity sufficient to allow continuous generation of aerosol for approximately six minutes, or a multiple of six minutes. In another example, the power source may have a capacity sufficient to allow a predetermined number of puffs, or discontinuous activation of the heating system.

[0012] The heating element may be a resistive heater.

[0013] The heating element may be a tubular heating element arranged to surround the aerosol-forming substrate in use.

[0014] The first predetermined period may have a duration between 40 seconds and 150 seconds.

[0015] The period for increasing the temperature of the heating element from the initial temperature to the first temperature may have a duration of 3 to 5 seconds.

[0016] The second temperature may be different from the first temperature.

[0017] Adjusting the temperature of the heating element to the second temperature during the second predetermined period of time may include decreasing the temperature of the heating element from the first temperature.

[0018] By reducing the temperature of the heating element during the second predetermined period of time, the amount of desired volatile compound vaporized in the aerosol inhaled by the user can match the amount vaporized during the first predetermined time, thereby providing the same sensory experience to the user.

[0019] Adjusting the temperature of the heating element to a second temperature during a second predetermined period of time can include decreasing the temperature of the heating element from the first temperature to the second temperature and then increasing the temperature of the heating element in a stepwise manner.

[0020] Reducing the heater temperature from the first temperature may include two successive temperature steps.

[0021] The temperature of the first temperature step may be lower than the temperature of the second temperature step.

[0022] Having two temperature steps in the second predetermined time period allows for improved control of the amount of vaporized desired volatile compound in the aerosol inhaled by the user, thereby providing the same sensory experience to the user. Furthermore, if the temperature of the second heating step is higher than the temperature of the first heating step, the amount of vaporized desired volatile compound will be consistent even as the amount of desired volatile compound depletes over time with heating.

[0023] The second temperature may be between 145 and 185 degrees Celsius.

[0024] Adjusting the heater temperature to the second temperature during the second predetermined period of time may include increasing the heater temperature from the first temperature.

[0025] The temperature of the heating element during the second predetermined period may be between 200 and 240 degrees Celsius.

[0026] The second predetermined period may have a duration of 100 to 280 seconds.

[0027] Controlling the power during heating of the aerosol-forming substrate to form an aerosol for inhalation by the user may further comprise adjusting the temperature of the heating element to be constant and equal to a third temperature during a third predetermined period of time, the third temperature corresponding approximately to the first temperature, the third predetermined period following the second predetermined period of time. The third predetermined period may immediately follow the second predetermined period of time.

[0028] The third predetermined period may have a duration between 30 seconds and 120 seconds.

[0029] Carrying out the heating of the aerosol-forming substrate to form an aerosol for inhalation by the user during three predetermined periods during which the temperature of the heating element is adjusted to each temperature allows for improved control of aerosol delivery. In particular, toward the end of the user session in the third predetermined period, the amount of desired volatile compound vaporized for inhalation by the user will be depleted. Raising the temperature of the heating element to about the first temperature allows the amount of desired volatile compound vaporized in the aerosol inhaled by the user to remain consistent with the amount during the first and second predetermined periods.

[0030] The power may be controlled during heating of the aerosol-forming substrate to form an aerosol for inhalation by a user based on a heating profile of a plurality of heating profiles, each heating profile defining how to regulate the temperature of the heating element during each of the predetermined periods of time.

[0031] The method may further include selecting a heating profile based on an identity of the aerosol-generating article.

[0032] The power may be controlled during heating of the aerosol-forming substrate to form an aerosol for inhalation by a user based on a heating profile of a plurality of heating profiles, each heating profile defining how to regulate the temperature of the heating element during a second predetermined period of time.

[0033] The method may further include selecting a heating profile based on an identity of the aerosol-generating article.

[0034] Controlling the power may further include, in a pre-heat mode, increasing the temperature of the heating element from an ambient temperature to an initial temperature.

[0035] The pre-heat mode ensures that the duration of the pre-heat mode is sufficient for the aerosol-forming substrate to reach a minimum operating temperature, so as to provide continuous power and be ready to reach the first operating temperature as quickly as possible to generate sufficient aerosol to be inhaled by the user, regardless of the physical state of the aerosol-forming substrate (e.g., dry or wet). This is particularly advantageous for aerosol-forming substrates with high aerosol former content (greater than 30 weight percent), because such substrates typically have a high water content after reaching thermal equilibrium.

[0036] The initial temperature may be between 140 and 170 degrees Celsius.

[0037] According to a further embodiment there is provided an aerosol generating device comprising: a heating chamber configured to at least partially receive an aerosol-generating article comprising an aerosol-forming substrate; a heating system comprising a heating element configured to externally heat the aerosol-forming substrate; a power source for providing power to the heating system; and a controller configured to control the power during heating of the aerosol-forming substrate to form an aerosol for inhalation by a user, the aerosol generating device increasing the temperature of the heating element from an initial temperature to a first temperature, the first temperature being maintained constant for a first predetermined period of time, the first temperature being between 180 and 230 degrees Celsius; and adjusting the temperature of the heating element to the second temperature for a second predetermined period of time, the second predetermined period of time being immediately following the first predetermined period of time and the second predetermined period of time being longer than the first predetermined period of time.

[0038] The heating element may be a resistive heater.

[0039] The heating element may be a tubular heating element arranged to surround the aerosol-forming substrate in use.

[0040] The first predetermined period may have a duration between 40 seconds and 150 seconds.

[0041] The period for increasing the temperature of the heating element from the initial temperature to the first temperature may be 3 to 5 seconds.

[0042] The second temperature may be different from the first temperature.

[0043] Adjusting the temperature of the heating element to the second temperature during the second predetermined period of time may include decreasing the temperature of the heating element from the first temperature.

[0044] Adjusting the temperature of the heating element to a second temperature during a second predetermined period of time can include decreasing the temperature of the heating element from the first temperature to the second temperature and then increasing the temperature of the heating element in a stepwise manner.

[0045] Reducing the heater temperature from the first temperature may include two successive temperature steps.

[0046] The temperature of the first temperature step may be lower than the temperature of the second temperature step.

[0047] The second temperature may be between 145 and 185 degrees Celsius.

[0048] Adjusting the heater temperature to the second temperature during the second predetermined period of time may include increasing the heater temperature from the first temperature.

[0049] The temperature of the heating element during the second predetermined period may be between 200 and 240 degrees Celsius.

[0050] The second predetermined period may have a duration of 100 to 280 seconds.

[0051] The controller may be further configured to control the power during heating of the aerosol-forming substrate to form an aerosol for inhalation by the user to regulate the temperature of the heating element to be constant and equal to a third temperature for a third predetermined period of time, the third temperature corresponding approximately to the first temperature, the third predetermined period following the second predetermined period of time. The third predetermined period may directly follow the first predetermined period of time.

[0052] The third predetermined period may have a duration between 30 seconds and 120 seconds.

[0053] The aerosol generating device may further comprise a memory configured to store a plurality of heating profiles, each heating profile defining a manner of adjusting the temperature of the heating element during each of the time periods, and the controller is further configured to control power during heating of the aerosol-forming substrate based on a heating profile of the plurality of heating profiles to form an aerosol for inhalation by a user.

[0054] The controller may be further configured to select the heating profile based on an identity of the aerosol-generating article.

[0055] The aerosol generating device may further comprise a memory configured to store a plurality of heating profiles, each heating profile defining a manner of adjusting the temperature of the heating element during a second predetermined period of time, and the controller is further configured to control power during heating of the aerosol-forming substrate based on a heating profile of the plurality of heating profiles to form an aerosol for inhalation by a user.

[0056] The controller may be further configured to select the heating profile based on an identity of the aerosol-generating article.

[0057] The controller may be further configured to control the power to raise the temperature of the heating element from an ambient temperature to an initial temperature in the pre-heat mode.

[0058] The initial temperature may be between 140 and 170 degrees Celsius.

[0059] According to a further embodiment, there is provided a system comprising an aerosol generating device as described above and an aerosol-generating article comprising an aerosol-forming substrate.

[0060] The aerosol-forming substrate may comprise one or more aerosol formers, the aerosol-forming substrate comprising a total aerosol former content of 30 weight percent or more.

[0061] As used herein in connection with the present invention, the term "aerosol former" is used to describe a compound that facilitates the formation of an aerosol during use and that is preferably substantially resistant to thermal decomposition at the operating temperatures of an aerosol-generating article or an aerosol-generating system that includes the aerosol-forming substrate.

[0062] As used herein with respect to the present invention, the term "total aerosol former content" is used to describe the combined content of all aerosol formers in an aerosol-forming substrate.

[0063] Unless otherwise stated, the weight percentages of the components of the aerosol-forming substrate listed herein are based on the dry weight of the aerosol-forming substrate.

[0064] The one or more aerosol formers may include at least one of 1,3-butanediol, glycerin, 1,3-propanediol, propylene glycol, triethylene glycol, glycerol monoacetate, glycerol diacetate, glycerol triacetate, dimethyl dodecanedioate, and dimethyl tetradecanedioate.

[0065] The aerosol-forming substrate may be a non-tobacco substrate.

[0066] The aerosol-forming substrate may be a solid or a gel.

[0067] As used herein in connection with the present invention, the term "solid" is used to describe an aerosol-forming substrate that has a stable size and shape and does not flow at 23°C.

[0068] As used herein in connection with the present invention, the term "gel" is used to describe an aerosol-forming substrate that contains two or more components, one of which is a liquid. Gels are primarily liquids by weight. Gels are substantially dilute crosslinked systems that do not exhibit flow when at steady state, although the liquid phase may still diffuse throughout the system.

[0069] The aerosol-forming substrate may further comprise nicotine.

[0070] As used herein in connection with the present invention, the term "nicotine" is used to describe nicotine, nicotine base, or nicotine salts. In embodiments in which the aerosol-forming substrate comprises nicotine base or nicotine salts, the amount of nicotine recited herein is the amount of free base nicotine or the amount of protonated nicotine, respectively.

[0071] The aerosol-forming substrate may comprise natural nicotine, or synthetic nicotine, or a combination of natural and synthetic nicotine.

[0072] The aerosol-forming substrate may further comprise one or more cellulosic agents and one or more carboxylic acids selected from fumaric acid, maleic acid, and malic acid.

[0073] The aerosol-forming substrate may have a total cellulosic agent content of at least 35 weight percent, and a total carboxylic acid content of at least 0.5 weight percent.

[0074] The aerosol-forming substrate may comprise water.

[0075] The aerosol-forming substrate may have a water content of from 5 percent to 35 percent by weight.

[0076] The aerosol-forming substrate may be a solid film.

[0077] As used herein in connection with the present invention, the term "film" is used to describe a solid aerosol-forming substrate having a thickness that is substantially less than its width or length.

[0078] As used herein in connection with the present invention, the term "thickness" is used to describe the smallest dimension between substantially parallel opposing surfaces of a solid aerosol-generating film.

[0079] As used herein, the terms "puff" and "inhalation" are used interchangeably and are intended to mean the action of a user drawing an aerosol into their body through their mouth or nose. Inhalation includes situations in which the aerosol is drawn into the user's lungs, as well as situations in which the aerosol is drawn only into the user's mouth or nasal passages before being expelled from the user's body.

[0080] As used herein, a "use session" refers to a period of use of a device beginning with activation of the device by a user. A use session may include a pre-heating phase in which the aerosol generating device is configured to supply power to a heating system to heat the aerosol-forming substrate to generate an aerosol. A use session may include a calibration phase for calibrating the heating system to more precisely control the temperature of the heating element. A use session may include a main phase in which a user may inhale the generated aerosol. The main phase may be sufficiently long for multiple puffs. The main phase may be sufficiently long for three, four, five, or six puffs. The main phase may be sufficiently long for seven or more puffs. At the end of the use phase, the aerosol generating device may be configured to stop supplying power to the heating system. The aerosol-forming substrate may be removed from the aerosol generating device at the end of the use session. The aerosol-forming substrate may be replaced in a subsequent use session. The duration of the use session between the start of the use session and the end of the use session may be at least one, two, three, four, five, or six minutes. Preferably, a usage session may have a duration of about a quarter of a minute.

[0081] As used herein in referring to an aerosol generating device, the terms "upstream" and "forward," as well as "downstream" and "rearward," are used to describe the relative locations of components, or portions of components, of the aerosol generating device in relation to the direction in which air flows through the aerosol generating device during use. An aerosol generating device according to the invention comprises a proximal end through which aerosol exits the device during use. The proximal end of the aerosol generating device may also be referred to as the mouth end or downstream end. The mouth end is downstream of the distal end. The distal end of the aerosol-generating article may also be referred to as the upstream end. Components or portions of components of an aerosol generating device may be described as being upstream or downstream of one another based on their relative location with respect to the airflow path of the aerosol generating device.

[0082] As used herein in referring to an aerosol-generating article, the terms "upstream" and "forward," as well as "downstream" and "rearward" are used to describe the relative positions of components or parts of components of the aerosol-generating article in relation to the direction in which air flows through the aerosol-generating article during use of the aerosol-generating article. The aerosol-generating article according to the present invention comprises a proximal end through which the aerosol exits the article during use. The proximal end of the aerosol-generating article may also be referred to as the mouth end or the downstream end. The mouth end is downstream of the distal end. The distal end of the aerosol-generating article may also be referred to as the upstream end. Components or parts of components of the aerosol-generating article may be described as being upstream or downstream of each other based on their relative positions between the proximal end of the aerosol-generating article and the distal end of the aerosol-generating article. The forward of a component or part of a component of the aerosol-generating article is the part that is at the end closest to the upstream end of the aerosol-generating article. The rearward of a component or part of a component of the aerosol-generating article is the part that is at the end closest to the downstream end of the aerosol-generating article.

[0083] As used herein, "aerosol cooling element" refers to a component of an aerosol-generating article that is located downstream of an aerosol-forming substrate such that, during use, the aerosol formed by the volatile compounds emitted from the aerosol-forming substrate passes through and is cooled by the aerosol cooling element before being inhaled by the user. Aerosol cooling elements have a large surface area but generate a low pressure drop. Filters and other mouthpieces that generate a high pressure drop (e.g., filters formed of fiber bundles) are not considered aerosol cooling elements. Chambers and cavities within an aerosol-generating article are not considered aerosol cooling elements.

[0084] As used herein, the term "mouthpiece" means that portion of an aerosol-generating article, device, or system that is placed into the mouth of a user for direct inhalation of the aerosol.

[0085] As used herein with reference to the present invention, the term "mode" refers to an operating mode that the controller is programmed to execute. For example, in a pre-heat mode, the controller is configured to execute a pre-programmed pre-heat process. In a heating mode, the controller is configured to execute a heating process. The term "stage" may be used interchangeably herein with the term "mode". The controller may be a microcontroller. The controller may comprise a microprocessor, such as a programmable microprocessor. The controller may comprise a non-volatile memory. The aerosol generating device may comprise an interface configured to allow transfer of data to and from the controller from an external device. The interface may allow uploading of software to the controller that runs on the programmable microprocessor. The interface may be a wired interface, such as a micro USB port, or a wireless interface. EXAMPLES

[0086] The present invention is defined in the claims. However, below is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of the other examples, embodiments, or aspects described herein.

[0087] Example 1: 1. A method of controlling aerosol generation in an aerosol generating device, the device comprising: a heating chamber configured to at least partially receive an aerosol-generating article comprising an aerosol-forming substrate; a heating system comprising a heating element configured to externally heat the aerosol-forming substrate; and a power source for providing power to the heating system, the method comprising: raising a temperature of the heating element from an initial temperature to a first temperature, the first temperature being maintained constant for a first predetermined period of time, the first temperature being between 180 and 230 degrees Celsius; adjusting the temperature of the heating element to the second temperature for a second predetermined period of time, the second predetermined period of time being immediately following the first predetermined period of time, the second predetermined period of time being longer than the first predetermined period of time, to form an aerosol for inhalation by a user, and controlling the power during heating of the aerosol-forming substrate. Example 2: The method of example 1, wherein the heating element is a resistive heater. Example 3: The method according to example 1 or 2, wherein the heating element is a tubular heating element configured to surround the aerosol-forming substrate in use. Example 4: The method according to any one of embodiments 1 to 3, wherein the first predetermined period of time has a duration between 40 seconds and 150 seconds. Example 5: The method according to any one of the preceding embodiments, wherein the period for increasing the temperature of the heating element from the initial temperature to the first temperature has a duration of 3 to 5 seconds. Example 6: The method according to any one of embodiments 1 to 5, wherein the second temperature is different from the first temperature. Example 7: The method of any one of Examples 1-6, wherein adjusting the temperature of the heating element to the second temperature during the second predetermined period of time comprises decreasing the temperature of the heating element from the first temperature. Example 8: The method of any one of Examples 1-7, wherein adjusting the temperature of the heating element to the second temperature during the second predetermined period of time comprises decreasing the temperature of the heating element from the first temperature to the second temperature, and then increasing the temperature of the heating element in a stepwise manner. Example 9: 9. The method of any one of claims 7 to 8, wherein decreasing the heater temperature from the first temperature comprises two successive temperature steps. Example 10: The method of example 9, wherein the temperature of the first temperature step is lower than the temperature of the second temperature step. Example 11: The method according to any one of the preceding claims, wherein the second temperature is between 145 and 185 degrees Celsius. Example 12: The method of any one of the preceding claims, wherein adjusting the heater temperature to the second temperature during the second predetermined period of time comprises increasing the heater temperature from the first temperature. Example 13: 13. The method of claim 12, wherein the temperature of the heating element during the second predetermined period is between 200 and 240 degrees Celsius. Example 14: The method according to any one of the preceding embodiments, wherein the second predetermined period of time is between 100 and 280 seconds. Example 15: The method of any one of Examples 1 to 14, wherein controlling the power during heating of the aerosol-forming substrate to form an aerosol for inhalation by the user further comprises adjusting the temperature of the heating element to be constant and equal to a third temperature during a third predetermined period of time, the third temperature corresponding approximately to the first temperature, and the third predetermined period of time following the second predetermined period of time. Example 16: The method of example 15, wherein the third predetermined period of time is between 30 seconds and 120 seconds. Example 17: A method according to one of Examples 1 to 16, wherein power is controlled during heating of the aerosol-forming substrate based on a heating profile of a plurality of heating profiles to form an aerosol for inhalation by a user, each heating profile defining a manner in which the temperature of the heating element is adjusted during each of the predetermined periods of time. Example 18: 20. The method of example 17, further comprising selecting a heating profile based on the identity of the aerosol-generating article. Example 19: The method of any one of Examples 1 to 16, wherein the power is controlled during heating of the aerosol-forming substrate based on a heating profile of a plurality of heating profiles to form an aerosol for inhalation by a user, each heating profile defining a manner in which the temperature of the heating element is adjusted during a second predetermined period of time. Example 20: 20. The method of example 19, further comprising selecting a heating profile based on the identity of the aerosol-generating article. Example 21: 21. The method of one of embodiments 1-20, wherein controlling the power further comprises increasing the temperature of the heating element from an ambient temperature to an initial temperature in a pre-heat mode. Example 22: 22. The method of claim 21, wherein the initial temperature is 140 to 170 degrees Celsius. Example 23: 1. An aerosol generating device comprising: a heating chamber configured to at least partially receive an aerosol-generating article comprising an aerosol-forming substrate; a heating system comprising a heating element configured to externally heat the aerosol-forming substrate; a power source for providing power to the heating system; and a controller configured to control the power during heating of the aerosol-forming substrate to form an aerosol for inhalation by a user, the aerosol generating device increasing a temperature of the heating element from an initial temperature to a first temperature, the first temperature being maintained constant for a first predetermined period of time, the first temperature being between 180 and 230 degrees Celsius; and adjusting the temperature of the heating element to a second temperature for a second predetermined period of time, the second predetermined period of time being immediately following the first predetermined period of time, the second predetermined period of time being longer than the first predetermined period of time. Example 24: 24. The aerosol generating device of Example 23, wherein the heating element is a resistive heater. Example 25: 25. An aerosol generating device as described in Example 23 or 24, wherein the heating element is a tubular heating element configured to surround the aerosol-forming substrate in use. Example 26: 26. The aerosol generating apparatus according to any one of Examples 23 to 25, wherein the first predetermined period has a duration of 40 seconds to 150 seconds. Example 27: 27. The aerosol generating apparatus according to any one of Examples 23 to 26, wherein the period for increasing the temperature of the heating element from the initial temperature to the first temperature is 3 to 5 seconds. Example 28: 28. The aerosol generating apparatus according to any one of Examples 23 to 27, wherein the second temperature is different from the first temperature. Example 29: An aerosol generating device described in one of Examples 23 to 28, wherein adjusting the temperature of the heating element to the second temperature during the second predetermined period includes lowering the temperature of the heating element from the first temperature. Example 30: An aerosol generating device described in one of Examples 23 to 29, wherein adjusting the temperature of the heating element to the second temperature during a second predetermined period of time includes lowering the temperature of the heating element from the first temperature to the second temperature and then increasing the temperature of the heating element in a stepwise manner. Example 31: 31. The aerosol generating device of embodiment 29 or 30, wherein decreasing the heater temperature from the first temperature comprises two successive temperature steps. Example 32: 32. The aerosol generating device of embodiment 31, wherein the temperature of the first temperature step is lower than the temperature of the second temperature step. Example 33: 33. The aerosol generating apparatus according to any one of Examples 23 to 32, wherein the second temperature is between 145 and 185 degrees Celsius. Example 34: An aerosol generating apparatus as described in one of Examples 23 to 28, wherein adjusting the heater temperature to the second temperature during the second predetermined period includes increasing the heater temperature from the first temperature. Example 35: 35. The aerosol generating apparatus of Example 34, wherein the temperature of the heating element during the second predetermined period is 200 to 240 degrees Celsius. Example 36: 36. The aerosol generating apparatus according to any one of Examples 23 to 35, wherein the duration of the second predetermined period is 100 to 280 seconds. Example 37: An aerosol generating device described in one of Examples 23 to 36, wherein the controller is further configured to control the power during heating of the aerosol-forming substrate to form an aerosol for inhalation by the user, and to adjust the temperature of the heating element to be constant and equal to a third temperature during a third predetermined period of time, the third temperature corresponding approximately to the first temperature, and the third predetermined period following the second predetermined period. Example 38: 38. The aerosol generating apparatus of Example 37, wherein the duration of the third predetermined period is 30 seconds to 120 seconds. Example 39: An aerosol generating device described in one of Examples 23 to 38, further comprising a memory configured to store a plurality of heating profiles, each heating profile defining a manner of adjusting the temperature of the heating element during each of the time periods, and the controller further configured to control power during heating of the aerosol-forming substrate based on a heating profile of the plurality of heating profiles to form an aerosol for inhalation by a user. Example 40: An aerosol generating device as described in Example 39, wherein the controller is further configured to select a heating profile based on the identity of the aerosol-generating article. Example 41: An aerosol generating device described in one of Examples 23 to 38, wherein the aerosol generating device further comprises a memory configured to store a plurality of heating profiles, each heating profile defining a manner of adjusting the temperature of the heating element during a second predetermined period of time, and the controller is further configured to control power during heating of the aerosol-forming substrate based on a heating profile of the plurality of heating profiles to form an aerosol for inhalation by a user. Example 42: An aerosol generating device as described in Example 41, wherein the controller is further configured to select a heating profile based on the identity of the aerosol-generating article. Example 43: An aerosol generating device described in one of Examples 23 to 42, wherein the controller is further configured to control power in the preheating mode to raise the temperature of the heating element from ambient temperature to an initial temperature. Example 44: 44. The aerosol generating apparatus according to claim 43, wherein the initial temperature is 140 to 170 degrees Celsius. Example 45: A system comprising the aerosol-generating device according to any one of Examples 23 to 44, and an aerosol-generating article comprising an aerosol-forming substrate. Example 46: The system of example 45, wherein the aerosol-forming substrate comprises one or more aerosol formers, and the aerosol-forming substrate comprises a total aerosol former content of 30 weight percent or more. Example 47: The system of Example 46, wherein the one or more aerosol formers include at least one of 1,3-butanediol, glycerin, 1,3-propanediol, propylene glycol, triethylene glycol, glycerol monoacetate, glycerol diacetate, glycerol triacetate, dimethyl dodecanedioate, and dimethyl tetradecanedioate. Example 48: The system of any one of Examples 45 to 47, wherein the aerosol-forming substrate is a non-tobacco substrate. Example 49: The system according to any one of Examples 45 to 48, wherein the aerosol-forming substrate is a solid or a gel. Example 50: The system of one of Examples 45-49, wherein the aerosol-forming substrate further comprises nicotine. Example 51: The system according to any one of Examples 45 to 50, wherein the aerosol-forming substrate further comprises one or more cellulosic agents and one or more carboxylic acids selected from fumaric acid, maleic acid, and malic acid. Example 52: The system of Example 51, wherein the aerosol-forming substrate has a total cellulosic agent content of at least 35 weight percent and a total carboxylic acid content of at least 0.5 weight percent. Example 53: The system of any one of Examples 55-62, wherein the aerosol-forming substrate comprises water. Example 54: The system of example 53, wherein the aerosol-forming substrate has a water content of 5 weight percent to 35 weight percent.

[0088] The embodiments will now be further described with reference to the figures. [Brief description of the drawings]

[0089] [Figure 1] FIG. 1 shows a schematic cross-sectional view of an aerosol-generating article that includes an aerosol-forming substrate. [Diagram 2] FIG. 2 shows a schematic cross-sectional view of an aerosol generating system comprising the aerosol-generating article shown in FIG. 1 and an electrically operated aerosol generating device comprising a resistive heater for externally heating the aerosol-forming substrate. [Diagram 3] FIG. 3 is a graph of temperature versus time showing a portion of a heating profile during user operation of an aerosol generating device. [Figure 4] FIG. 4 is a graph of temperature versus time showing a portion of a heating profile during user operation of an aerosol generating device. [Diagram 5]FIG. 5 is a graph of temperature versus time showing a portion of a heating profile during user operation of an aerosol generating device. [Figure 6] FIG. 6 is a graph of temperature versus time showing a portion of a heating profile during user operation of an aerosol generating device. [Figure 7] FIG. 7 is a graph of temperature versus time showing a portion of a heating profile during user operation of an aerosol generating device. [Figure 8] FIG. 8 is a graph of temperature versus time showing a portion of a heating profile during user operation of an aerosol generating device. [Figure 9] FIG. 9 is a flow diagram of a method for controlling aerosol generation in an aerosol generating device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0090] FIG. 1 is a schematic cross-sectional view of an aerosol-generating article 10 that includes an aerosol-forming substrate.

[0091] The aerosol-generating article 10 shown in Figure 1 comprises an aerosol-generating rod 12 and a proximal section 14 located downstream of the aerosol-generating rod 12. As shown in Figure 1, the aerosol-generating article 10 has an upstream or distal end 18 and a downstream or proximal end 20.

[0092] The proximal section 14 of the aerosol-generating article 10 includes a support element 22 located immediately downstream of the aerosol-generating rod 12, an aerosol cooling element 24 located immediately downstream of the support element 22, and a mouthpiece element 42 located immediately downstream of the aerosol cooling element 24.

[0093] The support element 22 may include a first hollow tubular segment 26. The first hollow tubular segment 26 is in the form of a hollow cylindrical tube made of cellulose acetate. The first hollow tubular segment 26 defines an interior cavity 28 that extends from an upstream end 30 of the first hollow tubular segment to a downstream end 32 of the first hollow tubular segment 20.

[0094] The aerosol cooling element 24 includes a second hollow tubular segment 34. The second hollow tubular segment 34 is in the form of a hollow cylindrical tube made of cellulose acetate. The second hollow tubular segment 34 defines an interior cavity 36 that extends from an upstream end 38 of the second hollow tubular segment to a downstream end 40 of the second hollow tubular segment 34.

[0095] As shown by the vertical lines in FIG. 1, the aerosol-generating article 10 includes a ventilation zone 60 provided at a location along the second hollow tubular segment 34 .

[0096] Mouthpiece element 42 is in the form of a cylindrical plug of low density cellulose acetate.

[0097] The aerosol-generating rod 12 comprises an aerosol-forming substrate. The aerosol-forming substrate may be a solid or a gel. The aerosol-forming substrate comprises one or more aerosol formers, such as glycerin or propylene glycol. The total aerosol former content of the aerosol-forming substrate may be 30 percent by weight or more. The total aerosol former content of the aerosol-forming substrate may be 40 percent by weight or more. The total aerosol former content of the aerosol-forming substrate may be 45 percent by weight or more. The aerosol-forming substrate may be a non-tobacco substrate that does not contain tobacco-containing material. Alternatively, the aerosol-forming substrate may comprise tobacco-containing material. In addition, the aerosol-forming substrate may comprise water. The aerosol-forming substrate may have a water content of 5 percent by weight to 35 percent by weight.

[0098] The aerosol-forming substrate may comprise nicotine. The aerosol-forming substrate may comprise one or more cellulosic agents. The aerosol-forming substrate may comprise one or more carboxylic acids. The one or more carboxylic acids may be selected from fumaric acid, maleic acid, and malic acid.

[0099] The aerosol-forming substrate may be a solid aerosol-generating film and the aerosol-generating rod 12 may comprise an assembly of crimped paper sheets coated with a solid aerosol-generating film.

[0100] The aerosol-generating article 10 comprises a heating element, such as a susceptor 44, located within the aerosol-generating rod 12. As shown in Figure 2, the susceptor 44 is surrounded by the aerosol-forming substrate and extends along the longitudinal axis of the aerosol-generating rod 12 from the upstream end of the aerosol-generating rod 12 to the downstream end of the aerosol-generating rod 12. The susceptor 44 is in direct contact with the aerosol-generating substrate.

[0101] The susceptor 44 may be in the form of a strip having a length of 12 millimeters, a width of 5 millimeters, and a thickness of 60 micrometers. The susceptor 44 includes at least two different materials. The susceptor 44 includes at least two layers, a first layer of a first susceptor material disposed in physical contact with a second layer of a second susceptor material. The first susceptor material and the second susceptor material may each have a Curie temperature. In this case, the Curie temperature of the second susceptor material is lower than the Curie temperature of the first susceptor material. The first material may not have a Curie temperature. The first susceptor material may be aluminum, iron, or stainless steel. The second susceptor material may be nickel or a nickel alloy.

[0102] Optionally, the aerosol-generating article 10 may include an upstream element (not shown) located immediately upstream from the aerosol-generating rod 12.

[0103] The upstream element may be in the form of a cylindrical plug of cellulose acetate surrounded by a rigid wrapper.

[0104] 2 is a schematic cross-sectional view of an aerosol-generating system comprising an aerosol-generating device 200 and an aerosol-generating article 10, the aerosol-forming substrate of which is externally heated. The aerosol-generating article 10 is the aerosol-generating article described above with respect to FIG.

[0105] The aerosol generating device 200 includes a heating chamber 210 for receiving the aerosol-generating article 10. The heating chamber 210 is formed by a stainless steel tube 230 and has a base 250 at its upstream end.

[0106] The aerosol-generating article 10 is at least partially received within the heating chamber 210. As shown in Figure 2, the aerosol-generating article 10 and the stainless steel tube 230 are configured such that a proximal end 20 of the aerosol-generating article 10, from which a user of the aerosol-generating article 10 can take a puff during use, protrudes outside the heating chamber 210 and outside the aerosol generating device 200 when the aerosol-generating article 10 is received within the heating chamber 210.

[0107] The aerosol generating device 200 further comprises a heating system including a heating element 245. The heating element 245 is bent around and surrounds the upstream end of the stainless steel tube 230. The portion of the stainless steel tube 230 surrounded by the heating element 245 corresponds to the portion of the heating chamber 210 in which the aerosol-forming substrate 225 of the aerosol-generating article 10 is received when the aerosol-generating article 10 is received within the heating chamber 210.

[0108] The heating system further comprises a temperature sensor 240. The temperature sensor 240 may be a Pt1000 type temperature sensor. The temperature sensor 240 is in thermal contact with the heater track of the heating element 245 and is configured to measure the temperature of the heater track of the heating element 245.

[0109] The heating element 245 comprises a first adhesive layer, a first polyimide substrate layer, a heating track, a second adhesive layer, a second polyimide layer, and a heat shrink layer. The temperature sensor 240 is positioned between the second polyimide layer and the heat shrink layer. The temperature sensor 240 comprises connecting wires for connecting the temperature sensor 240 to a controller 255.

[0110] A first adhesive layer is used to adhere the heating element 245 to the stainless steel tube 230. Sandwiching the heater track between the first and second polyimide layers provides a means to support the heater track in place and provides electrical insulation between the heater track and other components of the aerosol generating device 200, particularly the stainless steel tube 230. Polyimide is advantageously flexible, electrically insulating and able to withstand the normal operating temperatures of the aerosol generating device, particularly the heater track, during use. The heater track is a continuous conductive track of stainless steel that is deposited on one of the first or second polyimide layers during manufacture. The heater track is configured to heat up when an electrical current is passed through the heater track.

[0111] In other words, the heating element 245 is a resistive heating element 245. The heater track has a resistance of 1.1 ohms at room temperature. A second adhesive layer holds the first polyimide layer and the second polyimide layer together which keeps the heater track in place.

[0112] The heat shrink layer comprises a material capable of withstanding the normal operating temperatures of the aerosol generating device, particularly the heater track, during use.

[0113] The aerosol generating device 200 further comprises a power source 275, such as a battery. The power source 275 and the temperature sensor 240 are connected to the controller 255 via electrical wires and connections not fully shown in FIG. 2. The power source 275 is configured to power the heating element 245 and is connected to a connector on the heater track. The application of heat to the heating element 245 by the power source 275 is controlled by the controller 255.

[0114] The airflow channel 265 extends from the air inlet 260 of the aerosol generating device 200. Upstream of the heating chamber 210, the airflow channel 265 is defined primarily by airflow channel walls 270. Downstream of the airflow channel walls 270, the airflow channel 265 passes through an air inlet defined in the base 250 of the heating chamber 210. The airflow channel 265 then extends through the heating chamber 210. When the aerosol-generating article 10 is received within the heating chamber 210, the airflow channel 265 passes through the aerosol-generating article 10 and extends through the mouthpiece 42.

[0115] During use of the aerosol-generating system, the aerosol-generating article 10 is inserted into the heating chamber 210 by a user of the system. The user then activates the device. This may be done, for example, by pressing a button or by inhaling through the mouthpiece 42 of the aerosol-generating article 10, which is detected by a puff sensor, not shown in FIG.

[0116] After activation, the controller 255 is configured to control the supply of power from the power supply 275 to the heating element 245 to cause the heating track to heat up.

[0117] Heat from the heating track is conducted through the stainless steel tube 230 to the aerosol-forming substrate of the aerosol-generating article 10. This heating of the aerosol-forming substrate generates vapor that is released into the air that is drawn into the aerosol-forming article 10 via the airflow channels 265. The vapor cools and condenses into an aerosol. Thus, when the user inhales through the mouthpiece 42, the generated aerosol is drawn through the aerosol-forming article 10 and inhaled by the user.

[0118] Controlling the heating by the controller 255 is based on the temperature signal received from the temperature sensor 240. The controller 255 is configured to control the power provided to the heating element 245 to adjust the temperature of the heating element 245 based on the temperature measured by the temperature sensor.

[0119] Alternatively, the controller 255 may measure the value of the electrical resistance of the heating element 245 to obtain an indication of the temperature of the heating element 245. In such a scenario, the temperature sensor 240 is an optional component of the aerosol generation device 200.

[0120] The controller 255 obtains an indication of the temperature of the heating element 245 (e.g., the electrical resistance of the heating element) by measuring the electrical resistance of the heating element 245. The temperature indication is used to adjust the current supplied to the heating element 245 to maintain the heating element 245 near a target temperature. In other words, the controller adjusts the temperature of the heating element by adjusting the current supplied to the heating element 245.

[0121] This approach relies on three or more temperature calibration points at which the resistance of the heating element 245 is measured. For temperatures intermediate the calibration points, the resistance values ​​are extrapolated from the values ​​at the calibration points. The calibration point temperatures are selected to cover the expected temperature range of the heating element 245 during operation. Calibration of the heating element 245 to obtain the calibration points is performed at the time of manufacture, and the calibration points may be stored in the memory of the controller.

[0122] The controller 255 then adjusts the temperature of the heating element 245 by adjusting the current supplied to the heating element 245 based on the measured resistance.

[0123] 3-8 are graphs of heating element temperature versus time illustrating exemplary heating profiles of a heating element. The illustrated heating profiles define temperature values ​​for various heating modes (stages) and corresponding durations of each heating mode (stage). Although four heating modes are shown, it should be understood that the heating profile may comprise five or more heating modes.

[0124] The one or more heating profiles may be stored in a memory of the controller 255 or a memory associated with the controller 255. The controller 255 may be configured to select a heating profile during user operation of the device for generating an aerosol. For example, the aerosol generating device may include means for identifying an aerosol-generating article or an aerosol-forming substrate and may select a heating profile based on the identification. The heating profile may define the temperature and duration of all heating modes. Alternatively, the heating profile may define the temperature and duration of one or more of a subset of the heating modes, for example the heating modes following the pre-heat modes 310, 410, 510, 610, 710, 810.

[0125] The heating element is at an initial temperature in stages 310, 410, 510, 610, 710, 810. Stages 310, 410, 510, 610, 710, 810 are preheat stages in which the controller 255 is programmed to preheat the heating element 245 to a predetermined initial temperature for a predetermined duration.

[0126] The pre-heating stage ensures that the duration of the pre-heating stage is sufficient for the aerosol-forming substrate to reach a minimum operating temperature, whatever the physical state of the aerosol-forming substrate (e.g. dry or wet), in order to provide continuous power and to be prepared to reach the first operating temperature as quickly as possible in order to generate sufficient aerosol to be inhaled by a user.

[0127] In particular, aerosol-forming substrates comprising non-tobacco materials will have a higher thermal inertia than tobacco-based aerosol-forming substrates because non-tobacco aerosol-forming substrates contain a higher aerosol former content (e.g., greater than 30 weight percent) and a higher moisture content (e.g., greater than 5 weight percent). Thus, for non-tobacco aerosol-forming substrates with a higher moisture content, the pre-heating process ensures that the minimum operating temperature is reached before the main stage. The duration of the pre-heating mode is 10-20 seconds, preferably 11 seconds.

[0128] Following the pre-heat phase, the controller is configured to enter a first heating mode 320, 420, 520, 620, 720, 820. The first heating mode 320, 420, 520, 620, 720, 820 may be entered following detection of a timer, user actuation of the aerosol generating device, or a user puff indicating that a predetermined period of time has elapsed during the pre-heat phase 310, 410, 510, 610, 710, 810. Upon entering the first heating mode 320, 420, 520, 620, 720, 820, the controller rapidly increases the temperature of the heating element from an initial temperature to a first temperature.

[0129] The first temperature is selected so that the desired volatile compounds are evaporated from the substrate, but undesirable compounds that are evaporated or produced at higher temperatures are not released. Additionally, rapidly heating the heating element to the first temperature of the heating element improves the amount of desired volatile compounds vaporized, thereby improving delivery from the first puff to the user. The first temperature may be the maximum operating temperature of the heating element.

[0130] During the first heating mode 320, 420, 520, 620, 720, 820, the temperature remains constant at a first temperature for a first period of time. The initial temperature is above ambient temperature and is between 140 and 170 degrees Celsius. The first temperature may be between 180 and 230 degrees Celsius. As described above, by heating the heating element to a first temperature of the heating element in the first heating mode 320, 420, 520, 620, 720, 820, the thermal inertia of the aerosol-forming substrate is overcome and the amount of vaporized desired volatile compounds in the aerosol inhaled by the user, such as nicotine and aerosol former, is improved from the first puff.

[0131] After the first predetermined period of time, the controller enters a second heating mode 330, 430, 530, 630, 730, 830. In the second heating mode 330, 430, 530, 630, 730, 830, the controller adjusts the temperature of the heating element to one or more second temperatures during the second predetermined period of time. The one or more second temperatures may be between 180 and 230 degrees Celsius.

[0132] In the second heating mode 330, 430, 530, 630, 730, 830, the controller may adjust the temperature of the heating element to approximately correspond to the first temperature, as shown in FIG.

[0133] In the second heating mode 330, 430, 530, 630, 730, 830, the controller may adjust the temperature of the heating element to be lower than the first temperature, as shown in Figures 4, 5, 6 and 7. At the end of the first heating mode 320, 420, 520, 620, 720, 820, the heat will be diffused throughout the aerosol-forming substrate. Thus, by lowering the temperature of the heating element in the second heating mode, the amount of vaporized desired volatile compounds in the aerosol inhaled by the user remains consistent with that in the first heating mode 320, 420, 520, 620, 720, 820, thereby providing the same sensory experience to the user.

[0134] In the second heating mode 330, 430, 530, 630, 730, 830, the controller may adjust the temperature of the heating element to be higher than the first temperature, as shown in FIG.

[0135] In the second heating mode 330, 430, 530, 630, 730, 830, the controller may adjust the temperature of the heating element to a second temperature for a second period of time, as shown in Figures 3, 4 and 8. Alternatively, in the second heating mode, the controller may adjust the temperature of the heating element in multiple successive temperature steps. For example, Figure 5 shows two temperature steps having the same duration, where the temperature of the heating element is lower during the first temperature step than during the second temperature step. Figure 6 shows two temperature steps, where the temperature of the heating element is lower during the first temperature step than during the second temperature step, and the duration of the first temperature step is shorter than the duration of the second temperature step.

[0136] In the third heating mode 340, 440, 540, 640, 740, 840, the controller is configured to adjust the temperature of the heating element to a third temperature. The temperature of the heating element remains constant at the third temperature for a predetermined duration of a third period. As shown in Figures 3-8, the third temperature corresponds approximately to the first temperature. At this stage of the use session, the aerosol-forming substrate will be depleted of the desired volatile compound. Thus, increasing the temperature of the heating element to approximately the first temperature allows the amount of vaporized desired volatile compound in the aerosol inhaled by the user to remain consistent with the amount in the first and second heating modes.

[0137] Each of the predetermined periods may be the same length or may be different lengths. For example, a first predetermined period may be shorter than a subsequent second predetermined period, for example, as shown in Figures 4, 5, and 7. Additionally or alternatively, the first predetermined period may be shorter than a third predetermined period, for example, as shown in Figures 4 and 5. The second predetermined period may be longer than at least one of the first and third predetermined periods, for example, as shown in Figures 3-8. The first and third predetermined periods may have the same duration, for example, as shown in Figure 7.

[0138] The length of the first predetermined period may be between 40 seconds and 150 seconds, the length of the second predetermined period may be between 100 seconds and 280 seconds, and the length of the third predetermined period may be between 30 seconds and 120 seconds.

[0139] The length of the first predetermined period is selected such that the aerosol-forming substrate can provide good delivery of the volatilized desired compound in an aerosol, the first predetermined period being at least shorter than the second predetermined period ensuring good aerosol delivery to the user while ensuring consistency of the user experience throughout an entire use session.

[0140] A length of the second predetermined period that is at least longer than the first predetermined period provides improved control of the amount of desired volatile compound vaporized in the aerosol inhaled by the user, particularly when the second temperature is lower than the first temperature, thereby providing a consistent user experience for as long as possible throughout an entire use session.

[0141] FIG. 9 is a flow diagram illustrating a method of controlling aerosol generation in one of the aerosol generating devices by heating a heating item inserted into the heating chamber of the aerosol generating device, as described above.

[0142] The method begins at step 910 when a user activates heating of the heating element, as described above. For example, the user may press one or more buttons on the aerosol generating device to initiate heating of the heating element. Additionally or alternatively, the user may insert an aerosol-generating article into a heating chamber of the aerosol generating device to initiate heating of the heating element.

[0143] The method then proceeds to step 920 where the controller controls the power provided to the heating system to raise the temperature of the heating element from the ambient temperature to the initial temperature. During step 920, the controller is in a pre-heat mode and maintains the temperature of the heating element at the initial temperature for a predetermined period of time.

[0144] At step 930, the controller enters a first heating mode. In the first heating mode, the controller adjusts the temperature of the heating element to increase the temperature from an initial temperature to a first temperature. The first temperature is maintained for a first predetermined period of time.

[0145] At the end of the first predetermined period, the controller enters a second heating mode at step 940. In the second heating mode, the controller adjusts the temperature of the heating element to a second temperature. The second temperature may be maintained for a second predetermined period. Alternatively, the second temperature may be a first step of multiple temperature steps, each having a predetermined duration, the sum of the predetermined durations of each temperature step being the duration of the second predetermined period of the second heating mode. The second temperature may be lower than the first temperature, approximately equal to the first temperature, or higher than the first temperature.

[0146] At the end of the second predetermined time period, the controller enters a third heating mode at step 950. In the third heating mode, the controller adjusts the temperature of the heating element to a third temperature. The third temperature is maintained for a third predetermined time period. The third temperature is approximately equal to the first temperature and is maintained constant for the third time period.

[0147] It should be understood that the figures are for illustrative purposes and are not drawn to scale. Moreover, it will be understood that the aerosol-generating articles and aerosol-generating devices shown in the figures and described in detail above may have elements in addition to those discussed. Similarly, aerosol-generating articles or aerosol-generating devices according to the embodiments discussed herein may have fewer elements. Moreover, it will be apparent to one skilled in the art that the various dimensions of the elements discussed in connection with the various embodiments discussed herein are merely exemplary, and suitable alternative dimensions of the various elements may be selected.

[0148] For purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like are understood to be modified in all instances by the term "about." Also, all ranges include the maximum and minimum points disclosed, and include any intermediate ranges therein, which may or may not be specifically recited herein. Thus, in this context, the number A is understood as A±10%. Within this context, the number A may be considered to include a numerical value that is within the general standard error for the measurement of the property that the number A modifies. The number A may deviate by the percentages recited above, in some instances used in the appended claims, provided that the amount by which A deviates does not materially affect the basic and novel properties of the claimed invention. Also, all ranges include the maximum and minimum points disclosed, and include any intermediate ranges therein, which may or may not be specifically recited herein. Furthermore, in the context of the present invention, the expression that a number A "approximately corresponds to" should be understood as being equal to B ±10%.

Claims

1. A method for controlling aerosol generation in an aerosol generating device, wherein the device comprises a heating chamber configured to at least partially receive an aerosol generating article containing an aerosol forming substrate, a heating system comprising a heating element configured to heat the aerosol forming substrate from the outside, and a power supply for providing power to the heating system, wherein the method, during heating of the aerosol forming substrate, The temperature of the heating element is raised from an initial temperature to a first temperature, the first temperature is maintained constant for a first predetermined period, the first temperature is between 180 degrees Celsius and 230 degrees Celsius, and the first predetermined period has a duration of 40 seconds to 150 seconds. A method comprising adjusting the temperature of the heating element to a second temperature over a second predetermined period, controlling the power such that the second predetermined period is immediately after the first predetermined period, the second predetermined period is longer than the first predetermined period, and the duration of the second predetermined period is 100 to 280 seconds, thereby forming an aerosol for inhalation by a user.

2. The method according to claim 1, wherein adjusting the temperature of the heating element to the second temperature during the second predetermined period includes lowering the temperature of the heating element from the first temperature.

3. The method according to claim 2, wherein lowering the heater temperature from the first temperature includes two consecutive temperature steps.

4. The method according to claim 3, wherein the temperature in the first temperature step is lower than the temperature in the second temperature step.

5. The method according to one of claims 1 to 4, wherein controlling the power during heating of the aerosol-forming substrate to form an aerosol for inhalation by the user further includes adjusting the temperature of the heating element to a constant and equal third temperature during a third predetermined period, wherein the third temperature substantially corresponds to the first temperature, and the third predetermined period follows the second predetermined period.

6. The method according to one of claims 1 to 4, wherein the power is controlled during heating of the aerosol-forming substrate based on the heating profiles of a plurality of heating profiles to form an aerosol for inhalation by the user, and each heating profile defines a method for adjusting the temperature of the heating element during each of the predetermined periods.

7. The method according to claim 6, further comprising selecting the heating profile based on the identification of the aerosol-generating article.

8. Controlling the aforementioned power The method according to one of claims 1 to 4, further comprising raising the temperature of the heating element from the ambient temperature to the initial temperature in the preheating mode.

9. The method according to claim 8, wherein the initial temperature is 140 to 170 degrees Celsius.

10. A heating chamber configured to at least partially receive an aerosol-generating article containing an aerosol-forming substrate, A heating system comprising a heating element configured to heat the aerosol-forming substrate from the outside, and a power supply for providing power to the heating system, A controller, wherein during heating of the aerosol-forming substrate, The temperature of the heating element is raised from an initial temperature to a first temperature, the first temperature is maintained constant for a first predetermined period, the first temperature is between 180 degrees Celsius and 230 degrees Celsius, and the first predetermined period has a duration of 40 seconds to 150 seconds. Aerosol generator comprising: a controller configured to adjust the temperature of the heating element to a second temperature over a second predetermined period, and to control the power such that the second predetermined period is immediately after the first predetermined period, the second predetermined period is longer than the first predetermined period, and the duration of the second predetermined period is 100 to 280 seconds, thereby forming an aerosol for inhalation by the user.

11. The aerosol generating apparatus according to claim 10, wherein the heating element is a resistance heater.

12. It is a system, an aerosol generator according to one of claims 10 or 11, A system comprising an aerosol generating article containing the aerosol forming substrate.

13. The system according to claim 12, wherein the aerosol-forming substrate comprises one or more aerosol-forming bodies, and the aerosol-forming substrate contains a total aerosol-forming body content of 30% by weight or more.

14. The system according to claim 12, wherein the aerosol-forming substrate is a non-tobacco substrate.

15. The system according to claim 12, wherein the aerosol-forming substrate is a solid or a gel.

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