Heater assembly with microporous insulation foam

Abstract

The present invention relates to a heater assembly 10 for an aerosol generator. The heater assembly comprises a heating chamber 12 for heating an aerosol-forming substrate. The heater assembly comprises a heater casing 16 disposed around the heating chamber. The heater casing is disposed radially away from the heating chamber. The heater casing includes an airtight space 22. The airtight space includes a microporous insulating foam. The present invention further relates to an aerosol generator. The present invention further relates to an aerosol generation system.

Description

Technical Field

[0001] The present disclosure relates to a heater assembly for an aerosol generating device. The present disclosure further relates to an aerosol generating device. The present disclosure further relates to an aerosol generating system comprising an aerosol generating device and an aerosol forming substrate.

Background Art

[0002] It is known to provide an aerosol generating device for generating an inhalable vapor. Such a device may heat an aerosol forming substrate contained in an aerosol generating article without burning the aerosol forming substrate. The aerosol generating article may have a rod shape for insertion of the aerosol generating article into a heating chamber of the aerosol generating device. The heating element is typically disposed in or around the heating chamber to heat the aerosol forming substrate after the aerosol generating article is inserted into the heating chamber of the aerosol generating device.

[0003] The heat generated by the heating element may be inadvertently dissipated from the heating chamber. The heat may be dissipated to the environment or to other components of the aerosol generating system. The heat may be inadvertently dissipated from the heating chamber by free air convection. The heat may be inadvertently dissipated from the heating chamber by radiation. The heat may be inadvertently dissipated from the heating chamber by heat conduction through components of the aerosol generating device. The heat may be inadvertently dissipated from the heating chamber by heat conduction through components of the aerosol generating article, for example via the aerosol forming substrate. Heat dissipation from the heating chamber may cause heating of components of the device that are not intended to be heated. For example, the housing of the device that the user grasps may become uncomfortably hot. Heat dissipation from the heating chamber may cause heat loss within the heating chamber. Heat loss within the heating chamber may result in less efficient heating. An excessive amount of energy may be required to heat the heating chamber to the desired temperature.

[0004] It would be desirable to have an aerosol generator that can reduce heat loss from the heating chamber. It would be desirable to insulate the heating chamber from other components of the aerosol generator. It would be desirable to have an aerosol generator that can reduce heating of the outer housing of the device held by the user. It would be desirable to have an aerosol generator that can provide effective insulation. It would be desirable to have an aerosol generator that can provide insulation at a low manufacturing cost. It would be desirable to have an aerosol generator that can provide lightweight insulation. It would be desirable to have an aerosol generator that can have improved insulation. It would be desirable to have an aerosol generator that has heat-resistant insulation. It would be desirable to have an aerosol generator that has insulation that reduces or avoids the release of potentially harmful substances when heated. It would be desirable to have an aerosol generator that has insulation with good flame retardancy. It would be desirable to have an aerosol generator with a long lifespan. It would be desirable to have an aerosol generator that has insulation that can withstand multiple heating-cooling cycles. It would be desirable to have an aerosol generator that can have a reduced heater casing outer diameter. It would be desirable to have an aerosol generator that can have more compact device dimensions. [Overview of the project]

[0005] According to one embodiment of the present invention, a heater assembly for an aerosol generator is provided. The heater assembly may comprise a heating chamber for heating an aerosol-forming substrate. The heater assembly may further comprise a heater casing disposed around the heating chamber. The heater casing may be disposed radially away from the heating chamber. The heater casing may include an airtight space. The airtight space may include a microporous insulating foam.

[0006] According to one embodiment of the present invention, a heater assembly for an aerosol generator is provided. The heater assembly comprises a heating chamber for heating an aerosol-forming substrate. The heater assembly comprises a heater casing disposed around the heating chamber. The heater casing is disposed radially away from the heating chamber. The heater casing includes an airtight space. The airtight space includes a microporous insulating foam.

[0007] By providing an airtight space containing microporous insulating foam around the heating chamber, heat loss due to air circulation between the inside and outside air of the heater casing can be reduced or avoided. Furthermore, by providing an airtight space containing microporous insulating foam around the heating chamber, heat loss due to air convection within the airtight space can also be reduced or avoided. Providing an airtight space containing microporous insulating foam around the heating chamber can reduce radiant heat transfer. Advantageously, by providing an airtight space containing microporous insulating foam around the heating chamber, the insulation of the heating chamber to the outer surface of the heater casing can be improved. A heater assembly for an aerosol generator is provided that can reduce heat loss from the heating chamber by providing an airtight space containing microporous insulating foam around the heating chamber. A heater assembly for an aerosol generator is provided that can reduce heating of the outer housing of the user-grabbed device by providing an airtight space containing microporous insulating foam around the heating chamber. A heater assembly for an aerosol generator is provided that can provide effective insulation by providing an airtight space containing microporous insulating foam around the heating chamber. By providing an airtight space containing microporous insulating foam, improved insulation can be provided at the operating temperature of the aerosol generator compared to an airtight hollow space.

[0008] A heater assembly containing microporous insulating foam may provide an aerosol generator with heat-resistant insulation. A heater assembly containing microporous insulating foam may provide an aerosol generator with insulation that reduces or avoids the release of potentially harmful substances during heating. A heater assembly containing microporous insulating foam may provide an aerosol generator with good flame retardancy and insulation. A heater assembly containing microporous insulating foam may provide an aerosol generator with a long service life. A heater assembly containing microporous insulating foam may provide an aerosol generator with insulation that can withstand multiple heating-cooling cycles.

[0009] Microporous insulation foam can be polymer microporous insulation foam.

[0010] Microporous thermal insulation foam may include one or more of the following: polyaryletherketone (PAEK) foam, polyamide 46 (PA46) foam, polyamide 4T (PA4T) foam, polyphenylsulfone (PPSU) foam, polyethersulfone (PES) foam, and polyetherimide (PEI) foam.

[0011] Microporous thermal insulation foam includes or may consist of polyaryletherketone (PAEK) foam. Polyaryletherketone (PAEK) foam includes or may consist of one or more of polyetherketone (PEK) foam, polyetheretherketone (PEEK) foam, polyetherketoneketone (PEKK) foam, polyetheretherketoneketone (PEEKK) foam, and polyetherketoneetherketoneketone (PEKEKK) foam.

[0012] Polyaryl ether ketone (PAEK) forms may contain ether-to-ketone ratios of approximately 2:1, 1:1, 2:3, or 1:2.

[0013] The average pore size of microporous thermal insulation foam may be greater than 1 micrometer, preferably greater than 10 micrometers. The average pore size of microporous thermal insulation foam may be less than 500 micrometers, preferably less than 300 micrometers, more preferably less than 100 micrometers. The average pore size of microporous thermal insulation foam may be between 1 micrometer and 500 micrometers, preferably between 1 micrometer and 300 micrometers, more preferably between 1 micrometer and 100 micrometers, and more preferably between 1 micrometer and 50 micrometers. The average pore size can be determined using a scanning electron microscope (SEM). Measuring the pore size distribution of porous materials by processing SEM images is generally known and can be performed, for example, using the computer program ImageJ.

[0014] Microporous thermal insulation foam may include open porous structures. Microporous thermal insulation foam may include closed porous structures. Microporous thermal insulation foam may include partially open and partially closed porous structures.

[0015] Microporous thermal insulation foam can be made from a material that can withstand temperatures of at least 100 degrees Celsius, preferably at least 200 degrees Celsius, more preferably 100 to 500 degrees Celsius, more preferably 150 to 400 degrees Celsius, and more preferably 200 to 300 degrees Celsius without substantial degradation.

[0016] Microporous insulation foam may have a thermal conductivity of less than 0.05 W / m·K at room temperature, preferably less than 0.04 W / m·K, more preferably less than 0.03 W / m·K, more preferably less than 0.02 W / m·K, more preferably less than 0.01 W / m·K, more preferably less than 0.005 W / m·K, and more preferably less than 0.002 W / m·K. Microporous insulation foam may have a thermal conductivity of about 0.001 W / m·K at room temperature.

[0017] Microporous thermal insulation foam may have a thermal conductivity of less than 0.05 W / m·K, preferably less than 0.04 W / m·K, and more preferably less than 0.03 W / m·K, at a temperature of 280 degrees Celsius.

[0018] Microporous insulating foam may have a thermal conductivity of less than 0.05 W / m·K at 150 degrees Celsius, for example, about 0.025 W / m·K at temperatures.

[0019] The thermal conductivity can be determined according to ASTM C177.

[0020] Microporous thermal insulation foams may have a glass transition temperature of 100°C to 250°C, preferably 105°C to 235°C, and more preferably 110°C to 230°C. The glass transition temperature can be measured by DSC (Differential Scanning Calorimetry).

[0021] Microporous thermal insulation foam may have a melting point of 250°C to 450°C, preferably 280°C to 400°C, and more preferably 280°C to 350°C.

[0022] Microporous thermal insulation foams containing PEEK may have a glass transition temperature of 100°C to 200°C, preferably 120°C to 180°C, and more preferably 130°C to 170°C.

[0023] Microporous thermal insulation foams containing PEEK may have a melting point of 250 to 450 degrees Celsius, more preferably 280 degrees Celsius, and more preferably 300 to 350 degrees Celsius.

[0024] Microporous thermal insulation foam may have a density of less than 700 kilograms / cubic meter, preferably less than 600 kilograms / cubic meter, and more preferably less than 500 kilograms / cubic meter. Microporous thermal insulation foam may have a density of 400 kilograms / cubic meter to 700 kilograms / cubic meter. Microporous thermal insulation foam may have a density of 400 kilograms / cubic meter to less than 700 kilograms / cubic meter.

[0025] The micro-porous heat insulation foam can form one or more heat insulation layers. The one or more heat insulation layers can together have a thickness of 0.005 millimeters to 10 millimeters, preferably 0.01 millimeters to 5 millimeters, more preferably 0.1 millimeters to 4 millimeters, and even more preferably 0.2 millimeters to 2 millimeters.

[0026] The micro-porous heat insulation foam can form one heat insulation layer. The heat insulation layer can have a thickness of 0.005 millimeters to 10 millimeters, preferably 0.01 millimeters to 5 millimeters, more preferably 0.1 millimeters to 4 millimeters, and even more preferably 0.2 millimeters to 2 millimeters.

[0027] [[ID=z7]] The heater assembly can include a wrapping material disposed around the micro-porous heat insulation foam.

[0028] The wrapping material can be provided in the form of a film layer or a film. The film can be a multi-layer film.

[0029] The wrapping material can include or consist of one or more of polyether ether ketone (PEEK), polyaryl ether ketone (PAEK), polyimide (PI), polyphenyl sulfone (PPSU), polyether sulfone (PES), or polyether imide (PEI).

[0030] The heater assembly can include an aerogel. The aerogel can be added to the micro-porous heat insulation foam. The aerogel and the micro-porous heat insulation foam can form a mixture, such as a homogeneous mixture.

[0031] The aerogel can be a nano-porous aerogel.

[0032] The "operating temperature" depends on the type of aerosol generator and the aerosol-forming substrate used. The operating temperature of an aerosol generator may be in the range of 150 to 300 degrees Celsius. The operating temperature of an aerosol generator may be in the range of 200 to 230 degrees Celsius. The operating temperature of an aerosol generator may not exceed 280 degrees Celsius.

[0033] Airtight hollow spaces can contain air as an insulating material. However, the thermal conductivity of air increases as the temperature rises. Microporous insulating foam contains small cavities or pores. Because air or other gaseous compositions are sealed within these cavities, the thermal conductivity of microporous insulating foam as the temperature rises is lower compared to air. Microporous insulating foam can maintain its thermal conductivity at the operating temperature of an aerosol generator, compared to its thermal conductivity at room temperature. The low thermal conductivity of microporous insulating foam results in better insulation.

[0034] Due to better insulation, heater casings containing microporous insulating foam may have a reduced outer diameter. Providing heater casings with airtight spaces containing microporous insulating foam may result in aerosol generators with more compact device dimensions.

[0035] As used herein, the terms “upstream” and “downstream” are used to describe the relative position of a component or part of a component of an aerosol generator with respect to the direction through which air flows during its use. The aerosol generator according to the present invention has a proximal end through which aerosols exit the device during use. The proximal end of an aerosol generator 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 an aerosol generating article may also be referred to as the upstream end. Components or parts of a component of an aerosol generator may be described as being upstream or downstream of each other based on their relative positions with respect to the airflow path of the aerosol generator.

[0036] The proximal end of the heater assembly according to the present invention is configured to be positioned in a direction toward the mouth end or downstream end of the aerosol generator. The distal end of the heater assembly according to the present invention is configured to be positioned in a direction toward the distal end or upstream end of the aerosol generator. The longitudinal axis of the heating chamber may extend between the proximal end and the distal end of the heating chamber. The longitudinal axis of the heating chamber may extend between the proximal end and the distal end of the heater assembly.

[0037] The heating chamber may be configured to receive at least partially the aerosol-forming substrate. The heating chamber may include a cavity into which the aerosol-forming substrate can be inserted. The aerosol-forming substrate may be part of the aerosol-generating article. The cavity may have a shape corresponding to the shape of the aerosol-generating article received within the cavity. The cavity may have a circular cross-section. The cavity may have an elliptical or rectangular cross-section. The cavity may have an inner diameter corresponding to the outer diameter of the aerosol-generating article.

[0038] The heating chamber may have an opening at its proximal end to receive the aerosol-forming substrate. The opening may also serve as an air outlet. The heating chamber may have an air intake at its distal end.

[0039] The heating chamber may have an elongated shape. The heating chamber may be a hollow tube. The hollow tube may be formed from the wall of the heating chamber. The wall of the heating chamber may contain or be made of a metal or alloy. The wall of the heating chamber may contain or be made of stainless steel.

[0040] The heater casing may be disposed radially at a distance d from the heating chamber. The distance d may be measured perpendicular to the longitudinal axis of the heating chamber. The heating chamber may have walls. The heater casing may have walls. The distance d may be measured radially between the walls of the heating chamber and the walls of the heater casing. The distance d may be measured radially between the outside of the walls of the heating chamber and the inside of the walls of the heater casing.

[0041] The distance d between the heating chamber and the heater casing may be 1.5 mm to 7 mm. The distance d between the heating chamber and the heater casing may be 2 mm to 4 mm, preferably about 3.1 mm.

[0042] The heater casing may be coaxially aligned around the heating chamber. The heating chamber and heater casing may have matching shapes. The matching shapes may allow a constant radial distance d to be provided between the heater casing and the heating chamber.

[0043] The heater casing walls may match the shape of the heating chamber walls along the longitudinal axis of the heating chamber, such that the distance d can be approximately constant. For example, the heating chamber may be a hollow tube, and the heater casing walls may be cylindrical walls coaxially aligned around the heating chamber. The distance d may be measured radially between the outer diameter of the hollow tube of the heating chamber and the inner diameter of the cylindrical walls of the heater casing. For example, the heating chamber may be a hollow, cut cone, and the heater casing walls may be coaxially aligned conical walls. Those skilled in the art will understand that other types of matching shapes are possible. For example, the matching shape may be curved or wavy, or may include a combination of different shapes along the longitudinal axis of the heating chamber.

[0044] The heating chamber and heater casing may have deviant shapes. The shape of the heater casing walls may deviate to some extent from the shape of the heating chamber walls along the longitudinal axis of the heating chamber. The shape of the heater casing walls may deviate from the shape of the heating chamber walls along the longitudinal axis of the heating chamber such that the distance d does not vary by more than 1 millimeter along the longitudinal axis of the heating chamber. For example, the heating chamber may be a right-circular hollow cylinder, and the heater casing walls may be slightly conical hollow cylinders coaxially aligned around the heating chamber. Due to the conical shape of the heater casing walls, the distance d may vary by less than 1 millimeter along the longitudinal axis of the heating chamber.

[0045] The outer diameter of the heater casing may be measured in a direction perpendicular to the long axis of the heating chamber. The outer diameter of the heater casing may be 8 mm to 20 mm, preferably 14 mm to 18 mm, preferably about 16 mm.

[0046] The outer diameter of the heating chamber may be measured in a direction perpendicular to the longitudinal axis of the heating chamber. The ratio of the outer diameter of the heater casing to the outer diameter of the heating chamber may be 1.3 to 3.5, preferably 1.5 to 2.5, and more preferably about 2.0. In particular, in one embodiment, the outer diameter of the heating chamber may be about 5.6 mm and the outer diameter of the heater casing may be about 17 mm, resulting in a ratio of about 3.0. In one embodiment, the outer diameter of the heating chamber may be about 5.6 mm and the outer diameter of the heater casing may be about 16.5 mm, resulting in a ratio of about 2.95. In one embodiment, the outer diameter of the heating chamber may be about 7.6 mm and the outer diameter of the heater casing may be about 16.5 mm, resulting in a ratio of about 2.17.

[0047] The airtight space is airtightly sealed from the outside air. In other words, the inside of the airtight space is not fluidly connected to the outside air. This prevents heat loss caused by gas circulation between the airtight space and the air outside the heater assembly.

[0048] An airtight space may be at atmospheric pressure. The gas pressure within the airtight space may be 0.9 bar to 1.1 bar, preferably about 1.0 bar. The airtight space may be filled with a gaseous composition at approximately atmospheric pressure at about 20 degrees Celsius. As is known to those skilled in the art, temperature-dependent variations in the gas pressure within the airtight space may occur. Providing an airtight space at atmospheric pressure may be less expensive than manufacturing a vacuum-sealed space under vacuum. Vacuum-based insulation materials may be more expensive to manufacture.

[0049] It has been found that an airtight hollow space with a distance d of 1.5 to 7 millimeters significantly reduces heat loss. When such a distance d is provided, the air or other gaseous composition enclosed within the airtight space can be considered still air. Still air, or non-moving air, further reduces air convection within the airtight space. Heat loss due to air convection within the airtight space can be reduced.

[0050] The thermal conductivity of air increases with increasing temperature. At 25 degrees Celsius, the thermal conductivity of air is approximately 0.0262 W / m·K. At an operating temperature of 280 degrees Celsius, the thermal conductivity of air is already approximately 0.043 W / m·K. Therefore, to use air alone as an insulating material in an airtight hollow space, a relatively large gap thickness is required to provide sufficient insulation.

[0051] Microporous insulation foam may have a lower thermal conductivity than air at room temperature. At high temperatures, the difference between the thermal conductivity of air and microporous insulation foam can become even larger. The thermal conductivity of microporous insulation foam may not increase as rapidly as that of air. Microporous insulation foam can maintain its thermal conductivity almost even at high temperatures. For example, microporous insulation foam may have a thermal conductivity of 0.018 W / m·K at 20 degrees Celsius. At 200 degrees Celsius, the thermal conductivity is 0.022 W / m·K. At a temperature of 400 degrees Celsius, the thermal conductivity increases to 0.028 W / m·K according to ASTM C177. The thermal conductivity of this exemplary microporous insulation foam is approximately the same as that of air at room temperature, and is even higher than the maximum operating temperature of an aerosol generator. Lower thermal conductivity results in better insulation.

[0052] An airtight space containing insulating foam with low thermal conductivity can have a smaller thickness while still providing sufficient insulation. Instead of an airtight hollow space containing only air, an airtight space containing microporous insulating foam can have a smaller distance d. A smaller distance d can result in a smaller outer diameter for aerosol generators.

[0053] The microporous thermal insulation foam disclosed herein has a density of 500 kg / m². 3 Less than 400 kg / m 3 Less than, more preferably 300 kg / m 3 It may have a nominal density of less than [a certain value].

[0054] The microporous thermal insulation foam of the present invention may have a thermal conductivity of less than 0.05 W / m·K, preferably less than 0.04 W / m·K, more preferably less than 0.03 W / m·K, and more preferably less than 0.02 W / m·K, at 20 degrees Celsius, according to ASTM C177. The microporous thermal insulation foam may have a thermal conductivity of less than 0.05 W / m·K, preferably less than 0.04 W / m·K, and more preferably less than 0.03 W / m·K, at a temperature of 280 degrees Celsius, according to ASTM C177. The thermal conductivity of the microporous thermal insulation foam may increase by up to 40 percent, preferably up to 30 percent, and more preferably up to 20 percent, at a temperature of 280 degrees Celsius compared to the thermal conductivity of the microporous thermal insulation foam at 20 degrees Celsius.

[0055] At the operating temperature of an aerosol generator, an airtight space containing microporous insulating foam may have a lower thermal conductivity than the same airtight hollow space containing ambient air.

[0056] The airtight space can be completely filled with microporous insulating foam.

[0057] Alternatively, the airtight space does not have to be completely filled with microporous insulating foam. Not completely filling the airtight space with microporous insulating foam can reduce the weight of the aerosol generator. However, the airtight space may be at least partially filled with microporous insulating foam. The airtight space may be further at least partially filled with a gaseous composition. The gaseous composition may be at atmospheric pressure. The gaseous composition may be air. The gaseous composition may contain one or more of nitrogen, argon, carbon dioxide, oxygen, krypton, sulfur hexafluoride or a mixture thereof, or other suitable gaseous compositions.

[0058] The weight of the aerosol generator can be reduced by providing an additional gaseous composition in an airtight space. Manufacturing costs can also be reduced by providing a gaseous composition in an airtight space.

[0059] The volume of the airtight space filled with microporous insulating foam may be 30, 40, 50, 60, 70, 80, or 90 volume percent. The ratio of microporous insulating foam to the gaseous composition may depend on the operating temperature of the aerosol generator. Aerosol generators with higher operating temperatures may require more microporous insulating foam.

[0060] The airtight space may contain at least one void. The gaseous composition may be provided within the void.

[0061] An airtight space may contain one void. An airtight space may contain two voids. An airtight space may contain three voids. Microporous insulating foam may be sandwiched radially between two voids.

[0062] The void may have a thickness measured in a direction perpendicular to the longitudinal axis of the heating chamber. The thickness of the void may be 0.5 mm to 4 mm, preferably 1 mm to 3 mm, and more preferably about 2 mm.

[0063] One or more voids may be present within the microporous insulation foam. One or more voids may extend in a direction parallel to the longitudinal axis of the aerosol generator. One or more voids may have a longitudinal extension that is the same length as, or shorter than, the longitudinal extension of the microporous insulation foam. One or more voids may have a circular cross-section. Alternatively, one or more voids do not have to extend around the entire circumference of the microporous insulation foam. One or more voids may be completely enclosed by the microporous insulation foam. One or more voids may be in direct contact with the first and second connecting walls, as will be described in more detail below. One or more voids may be in direct contact with the heating chamber. One or more voids may be in direct contact with the heater casing.

[0064] By providing voids within an airtight space, the weight of the aerosol generator can be reduced. By providing voids within an airtight space, manufacturing costs can be reduced.

[0065] Microporous insulating foam may be in direct contact with the heating chamber. Microporous insulating foam may be surrounded by voids. The temperature around the heating chamber may decrease radially as the distance from the long axis of the heating chamber increases. Microporous insulating foam may provide better insulation than air, for example, at higher temperatures. An assembly in which microporous insulating foam is in direct contact with a heating chamber surrounded by voids may have improved insulation than an assembly in which it is arranged in the opposite direction.

[0066] The heater assembly may further include a first connecting wall connecting the heating chamber and the heater casing, and a second connecting wall connecting the heating chamber and the heater casing. An airtight space may be defined between the heating chamber, the heater casing, and the first and second connecting walls. The airtight space may be limited by the walls of the heating chamber and heater casing, and the first and second connecting walls. The first and second connecting walls may provide easy assembly of the airtight space. The first and second connecting walls may provide easy manufacture of the airtight space. By providing the first and second connecting walls, a defined distance d of the heater casing from the heating chamber can be ensured. By providing the first and second connecting walls, the precise placement of the microporous insulation foam can be ensured. The first and second connecting walls may be in contact with the microporous insulation foam, thereby preventing heat loss due to air convection over the proximal and distal ends of the microporous insulation foam.

[0067] Each of the first and second connecting walls may extend between the wall of the heating chamber and the wall of the heater casing. The first and second connecting walls may seal and connect the heater casing to the outer wall of the heating chamber. The connecting walls may be oriented perpendicular to the longitudinal axis of the heating chamber. The first connecting wall may be a proximal connecting wall. The second connecting wall may be a distal connecting wall.

[0068] The microporous insulation foam may be in direct contact with the heating chamber. The microporous insulation foam may be in direct contact with the heater casing. The microporous insulation foam may be in direct contact with the first and second connecting walls. The microporous insulation foam may be in direct contact with the heating chamber and the heater casing. The microporous insulation foam may be in direct contact with the heating chamber, the heater casing, and the first and second connecting walls. The microporous insulation foam may be installed between the first and second connecting walls. The microporous insulation foam may be installed between the first and second connecting walls, but may not be in contact with one or both of the heater casing and the heating chamber.

[0069] Microporous insulation foam may have elongated extensions. Microporous insulation foam may extend parallel to the long axis of the heating chamber. Microporous insulation foam may be a hollow tube extending around the heating chamber.

[0070] The microporous insulation foam may have a thickness measured in a direction perpendicular to the longitudinal axis of the heating chamber. The thickness of the microporous insulation foam may be the same as the distance d. The thickness of the microporous insulation foam may be 1 mm to 7 mm, preferably 2 mm to 6 mm, and more preferably 3 mm to 5 mm.

[0071] Microporous insulation foam can be formed from a single element. Alternatively, microporous insulation foam can be formed from at least two insulation elements. Microporous insulation foam can be formed from two insulation elements. Microporous insulation foam can be formed from at least a first insulation element including at least a first connecting element and a second insulation element including at least a second connecting element. The first and second connecting elements may be configured as matching connecting elements. When connected, the matching connecting elements may enable the connection of the first and second microporous insulation elements. The connected first and second connecting elements may result in an overall insulation foam that forms a hollow tube. The hollow tube may have an inner diameter corresponding to the outer diameter of the heating chamber. By providing microporous insulation foam from two insulation elements, a simple assembly of microporous insulation foam can be provided around the heating chamber. By forming microporous insulation foam from two insulation elements, a perfect morphological fit between the microporous insulation foam and the heating chamber can be provided. Better insulation can be ensured by providing a perfect morphological fit between the microporous insulation foam and the heating chamber.

[0072] The first and second connecting elements may be configured as male and female connecting elements, shape-fitting connecting elements, snap-fitting connecting elements, bayonet-type connecting elements or combinations thereof, or other commonly used connecting elements known to those skilled in the art. The first connecting element may include a male connecting element, and the second connecting element may include a female connecting element. The first and second connecting elements may include shape-fitting connecting elements. The first and second connecting elements may include snap-fitting connecting elements. The first and second connecting elements may include bayonet-type connecting elements.

[0073] Microporous insulation foam can be constructed as a two-part assembly. The two-part assembly may include a first insulation element and a second insulation element. The first and second insulation elements may be, for example, in the form of hollow semi-cylindrical elements. The hollow semi-cylindrical elements may include matching first and second connecting elements. When connected, the hollow semi-cylindrical elements may form a single hollow tube. The inner diameter of the hollow tube may be the same size as the outer diameter of the heating chamber. This ensures easy assembly. On the other hand, microporous insulation foam formed as a single element with the same inner diameter as the outer diameter of the heating chamber may be more difficult to assemble around the heating chamber due to friction. Proximity or direct contact between the microporous insulation foam and the heating chamber can improve the insulation of the heating chamber.

[0074] The heating chamber may include a temperature sensor. The temperature sensor may be located on top of the heating chamber. The microporous insulating foam may have a shape that matches the temperature sensor. The microporous insulating foam may have a cavity facing the temperature sensor. The microporous insulating foam may completely enclose the heating chamber. The temperature sensor may be surrounded by the microporous insulating foam. The temperature sensor may be sandwiched between the heating chamber and the microporous insulating foam.

[0075] The heater assembly may further include a heating element. The heating chamber may include a heating element.

[0076] The heating element may be arranged at least partially around the heating chamber. The heating element may be arranged at least partially around the wall of the heating chamber. Preferably, the heating element is arranged so as to completely coaxially surround the outer peripheral portion of the wall of the heating chamber. The heating element may be arranged along at least a portion of the longitudinal axis of the heating chamber.

[0077] The heating element may comprise one or more conductive tracks on an electrically insulated substrate. The one or more conductive tracks may be resistance heating tracks. The one or more conductive tracks may be configured as inductively heated susceptors. The electrically insulated substrate may be a flexible substrate.

[0078] The heating element may be flexible and can be wrapped around the heating chamber. The heating element may be positioned between the heating chamber and the heater casing.

[0079] Microporous insulation foam may have a longitudinal extension that is the same as or larger than the longitudinal extension of the heat-generating element. This ensures adequate insulation of the heat generated by the heat-generating element.

[0080] Microporous insulation foam can extend around a heat source. Microporous insulation foam can come into direct contact with a heat source.

[0081] In all aspects of this disclosure, the heating element may include an electrically resistive material. Suitable electrically resistive materials include, but are not limited to, semiconductors such as doped ceramics, conductive ceramics (e.g., molybdenum disilide), carbon, graphite, metals, alloys, and composite materials made of ceramic and metallic materials. Such composite materials may include doped or undoped ceramics.

[0082] As described, in any aspect of this disclosure, the heating element may be part of the heating chamber of a heater assembly for an aerosol generator. The heater assembly may comprise an internal heating element, an external heating element, or both internal and external heating elements, where “internal” and “external” refer to the aerosol-forming substrate. The internal heating element may take any preferred form. For example, the internal heating element may take the form of a heating blade. Alternatively, the internal heater may take the form of a casing or substrate having different conductive or electrically resistive metal tubes. Alternatively, the internal heating element may be one or more heating needles or rods passing through the center of the aerosol-forming substrate. Other alternatives include heating wires or filaments, such as Ni-Cr (nickel-chromium), platinum, tungsten, or alloy wires or heating plates. Optionally, the internal heating element may be placed in or on a rigid carrier material. In one such embodiment, the electrically resistive heating element may be formed using a metal having a clear relationship between temperature and resistivity. In such an exemplary device, the metal may be formed as a track on a suitable insulating material such as ceramic, and then sandwiched between other insulating materials such as glass. The heater thus formed can be used during operation to both heat a heating element and to monitor its temperature.

[0083] The external heating element can take any preferred form. For example, the external heating element may take the form of one or more flexible heating foils on a dielectric substrate such as polyimide. The flexible heating foils may be shaped to fit around a substrate receiving cavity. Alternatively, the external heating element may take the form of a metal grid, a flexible printed circuit board, a molded interconnect (MID), a ceramic heater, a flexible carbon fiber heater, or may be formed on a substrate of a preferred shape using coating techniques such as plasma deposition. The external heating element may also be formed using a metal having a clear relationship between temperature and resistivity. In such exemplary devices, the metal may be formed as a track between two layers of a preferred insulating material. The external heating element formed in this manner may be used both to heat the external heating element and to monitor its temperature during operation.

[0084] The heating element advantageously heats the aerosol-forming substrate by thermal conduction. The heating element may be in at least partial contact with the substrate or the support on which the substrate is deposited. Alternatively, heat from either an internal or external heating element may be conducted to the substrate by a thermally conductive element.

[0085] During operation, the aerosol-forming substrate may be completely contained within the aerosol generator. In this case, the user may inhale through the mouthpiece of the aerosol generator. Alternatively, during operation, a smoking article containing the aerosol-forming substrate may be partially contained within the aerosol generator. In this case, the user may inhale directly from the smoking article.

[0086] The heating element may be configured as an induction heating element. The induction heating element may comprise an induction coil and a susceptor. Generally, a susceptor is a material that has the ability to generate heat when penetrated by an alternating magnetic field. According to the present invention, the susceptor may be conductive, magnetic, or both conductive and magnetic. An alternating magnetic field generated by one or more induction coils heats the susceptor, which then transfers heat to the aerosol-forming substrate, thereby forming an aerosol. Heat conduction may be primarily by conduction. Such heat transfer is best when the susceptor is in close thermal contact with the aerosol-forming substrate. When an induction heating element is employed, it may be configured as an internal heating element as described herein, or as an external heater as described herein. When the induction heating element is configured as an internal heating element, the susceptor element is preferably configured as a pin or blade for penetrating the aerosol-generating article. When the induction heating element is configured as an external heating element, the susceptor element is preferably configured as a cylindrical susceptor that at least partially surrounds the cavity or forms the side wall of the cavity.

[0087] The heating chamber may include a central region containing a heating element. The term "central region" refers to the longitudinal axis. The heating chamber may further include a proximal region and a distal region. The proximal and distal regions may be spaced apart from the heating element in the longitudinal axis direction. During use, the proximal and distal regions may be colder than the central region of the heating chamber. A first connecting wall may be in contact with the heating chamber in the proximal region, and a second connecting wall may be in contact with the heating chamber in the distal region. Thus, the first and second connecting walls may be in contact with the heating chamber at its coldest point during use. This can further reduce heat loss from the heating chamber to the connecting walls and heater casing. Insulation can be further improved.

[0088] The walls of the heating chamber may be made of stainless steel. This can advantageously improve the effect that the proximal and distal regions can become cooler than the central region of the heating chamber during use.

[0089] The thickness of the heater casing walls may be less than about 2 millimeters. The thickness of the heater casing walls may be less than 1.2 millimeters, preferably about 0.8 millimeters. The thickness of one or both of the first and second connecting walls may be less than 1.2 millimeters, preferably about 0.8 millimeters. Having such thin walls can minimize the thermal mass of the heater casing. This can further reduce heat loss from the heating chamber.

[0090] The heater casing walls and one or more of the first and second connecting walls may be made of a low thermal conductivity material. This can further reduce heat loss from the heating chamber. The heater casing walls may contain or be made of a plastic material. The first and second connecting walls may contain or be made of a plastic material. The plastic material may contain one or both of polyarylether ketone (PAEK), polyetherether ketone (PEEK), and polyphenylene sulfone (PPSU). The plastic material preferably contains polyphenylene sulfone (PPSU).

[0091] The interior walls of the heater casing may include a metal cladding. The interior of one or both of the first and second connecting walls may include a metal cladding. The metal cladding may reduce the emissivity on the interior of the wall. For example, the emissivity of a PEEK wall may be reduced from about 0.95 to about 0.4. The metal cladding may reflect the heat radiation emitted from the heating chamber. The metal cladding may provide additional insulation of the heating chamber to the outside of the heater casing. The metal cladding may be a low-emissivity metal cladding. The metal cladding may include one or more of aluminum, gold, and silver.

[0092] The present invention further relates to an aerosol generator comprising the heater assembly described herein.

[0093] The aerosol generator preferably includes a power source configured to supply power to the heating element. The power source preferably includes a power supply. The power supply 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 supply may require recharging. For example, the power supply may have sufficient capacity to enable continuous aerosol generation for about six minutes, or for a time period that is a multiple of six minutes. In another embodiment, the power supply may have sufficient capacity to enable a predetermined number of fume extractions or discontinuous operation of the heater assembly.

[0094] The power source may include control electronics. The control electronics may include a microcontroller. Preferably, the microcontroller is a programmable microcontroller. The electrical circuit may include further electronic components. The electrical circuit may be configured to regulate the power supply to the heater assembly. Power may be supplied to the heater assembly continuously after the system has been activated, or intermittently (e.g., with each smoke extraction). Power may be supplied to the heater assembly in the form of current pulses.

[0095] The present invention further relates to an aerosol generating system comprising an aerosol generator and an aerosol-forming substrate as described herein. The aerosol-forming substrate may be configured to be at least partially received within a heating chamber. The aerosol-forming substrate may be a solid aerosol-forming substrate. The aerosol-forming substrate may form part of an aerosol-generating article. The aerosol-generating article may be configured to be at least partially inserted into a heating chamber.

[0096] As used herein, the term “aerosol-forming substrate” refers to a substrate having the ability to release volatile compounds that can form aerosols. Volatile compounds may be released by heating or burning the aerosol-forming substrate. As an alternative to heating or burning, in some cases, volatile compounds may be released by chemical reactions or by mechanical stimuli such as ultrasound. The aerosol-forming substrate may be solid or liquid, or may contain both solid and liquid components. The aerosol-forming substrate may be part of an aerosol-generating article.

[0097] The aerosol-forming substrate may be a solid aerosol-forming substrate. The aerosol-forming substrate may contain both solid and liquid components. The aerosol-forming substrate may contain tobacco-containing materials that include volatile tobacco-flavored compounds released from the substrate upon heating. The aerosol-forming substrate may contain non-tobacco materials. The aerosol-forming substrate may contain aerosol-forming bodies that facilitate the formation of high-density and stable aerosols. Examples of suitable aerosol-forming bodies include glycerin and propylene glycol.

[0098] As used herein, the term "aerosol-generating article" refers to an article comprising an aerosol-forming substrate having the ability to release volatile compounds capable of forming aerosols. Aerosol-generating articles may be disposable.

[0099] As used herein, the term “aerosol generator” refers to a device that interacts with an aerosol-forming substrate to generate an aerosol. An aerosol generator may interact with either or both an aerosol-generating article containing an aerosol-forming substrate and / or a cartridge containing an aerosol-forming substrate. In some examples, an aerosol generator may heat the aerosol-forming substrate to facilitate the release of volatile compounds from the substrate. An electrically operated aerosol generator may include an atomizer, such as an electric heater, for heating the aerosol-forming substrate to form an aerosol.

[0100] As used herein, the term "aerosol generating system" refers to a combination of an aerosol-forming substrate and an aerosol generating device. When the aerosol-forming substrate forms part of an aerosol-generating article, the aerosol generating system refers to a combination of the aerosol generating device and the aerosol-generating article. In an aerosol generating system, the aerosol-forming substrate and the aerosol generating device work together to generate an aerosol. [Brief explanation of the drawing]

[0101] [Figure 1]Figure 1 shows one embodiment of a heater assembly for an aerosol generator. [Figure 2] Figure 2 shows one embodiment of the heating chamber of the heater assembly. [Figure 3] Figure 3 shows one embodiment of a heater assembly for an aerosol generator. [Figure 4] Figure 4 shows one embodiment of a heater assembly for an aerosol generator. [Figure 5] Figure 5 shows one embodiment of a heater assembly for an aerosol generator. [Figure 6] Figure 6 shows one embodiment of a heater assembly for an aerosol generator. [Figure 7] Figure 7 shows one embodiment of the microporous thermal insulation foam used in a heater assembly for an aerosol generator. [Figure 8] Figure 8 shows one embodiment of an aerosol generator. [Figure 9] Figure 9 shows one embodiment of an aerosol generator. [Figure 10] Figure 10 shows one embodiment of an aerosol generator. [Modes for carrying out the invention]

[0102] [Examples] A non-exclusive list of non-limiting embodiments is provided below. One or more features of these embodiments may be combined with one or more features of any of the features described above, for example, one or more features of other embodiments, forms, or aspects described herein.

[0103] Example 1: A heater assembly for an aerosol generator, A heating chamber for heating the aerosol-forming substrate, A heater assembly comprising: a heater casing disposed around a heating chamber, disposed radially away from the heating chamber, the heater casing including an airtight space, and the airtight space including a microporous insulating foam. Example 2: The heater assembly described in Example 1, wherein the microporous insulation foam is a polymer microporous insulation foam. Example 3: The heater assembly according to Example 2, wherein the microporous insulating foam comprises one or more of the following: polyaryletherketone (PAEK) foam, polyamide 46 (PA46) foam, polyamide 4T (PA4T) foam, polyphenylsulfone (PPSU) foam, polyethersulfone (PES) foam, and polyetherimide (PEI) foam. Example 4: The heater assembly according to Example 3, wherein the microporous insulating foam includes polyaryletherketone (PAEK) foam. Example 5: The heater assembly according to Example 4, wherein the polyaryletherketone (PAEK) foam comprises one or more of the following: polyetherketone (PEK) foam, polyetheretherketone (PEEK) foam, polyetherketoneketone (PEKK) foam, polyetheretherketoneketone (PEEKK) foam, and polyetherketoneetherketoneketone (PEKEKK) foam. Example 6: A heater assembly according to Example 4 or 5, wherein the polyaryletherketone (PAEK) foam contains an ether-to-ketone ratio of approximately 2:1, approximately 1:1, approximately 2:3, or approximately 1:2. Example 7: A heater assembly according to any one of Examples 1 to 6, wherein the average pore size of the microporous thermal insulation foam is 1 micrometer to 500 micrometers, preferably 1 micrometer to 300 micrometers, more preferably 1 micrometer to 100 micrometers, and more preferably 1 micrometer to 50 micrometers. Example 8: A heater assembly according to any of Examples 1 to 7, wherein the microporous thermal insulation foam includes an open porous structure, a closed porous structure, or a partially open porous structure and a partially closed porous structure. Example 9: A heater assembly according to any one of Examples 1 to 8, wherein the microporous thermal insulation foam is made of a material capable of withstanding temperatures of at least 100 degrees Celsius, preferably at least 200 degrees Celsius, more preferably 100 to 500 degrees Celsius, more preferably 150 to 400 degrees Celsius, and more preferably 200 to 300 degrees Celsius without substantial degradation. Example 10: The microporous insulating foam has a thermal conductivity of less than 0.05 W / m·K, preferably less than 0.04 W / m·K, and more preferably less than 0.03 W / m·K at room temperature, and / or A heater assembly according to any one of Examples 1 to 9, wherein the microporous insulating foam has a thermal conductivity of less than 0.05 W / m·K, preferably less than 0.04 W / m·K, and more preferably less than 0.03 W / m·K at a temperature of 280 degrees Celsius. Example 11: A heater assembly according to any one of Examples 1 to 10, wherein the thermal conductivity of the microporous insulation foam is increased by up to 40 percent, preferably up to 30 percent, and more preferably up to 20 percent at a temperature of 280 degrees Celsius compared to the thermal conductivity of the microporous insulation foam at room temperature. Example 12: A heater assembly according to any one of Examples 1 to 11, wherein the microporous thermal insulation foam has a glass transition temperature of 100 to 250 degrees Celsius, preferably 105 to 235 degrees Celsius, and more preferably 110 to 230 degrees Celsius. Example 13: A heater assembly according to any one of Examples 1 to 12, wherein the microporous thermal insulation foam has a melting point of 250 to 450 degrees Celsius, preferably 280 to 400 degrees Celsius, and more preferably 280 to 350 degrees Celsius. Example 14: A heater assembly according to any of Examples 1 to 13, wherein the microporous thermal insulation foam has a density of less than 700 kilograms / cubic meter, preferably less than 600 kilograms / cubic meter, and more preferably less than 500 kilograms / cubic meter. Example 15: A heater assembly according to any one of Examples 1 to 14, wherein the microporous insulation foam forms one or more insulation layers, preferably the microporous insulation foam forms one insulation layer. Example 16: The heater assembly according to Example 15, wherein the heat insulating layer has a thickness of 0.005 mm to 10 mm, preferably 0.01 mm to 5 mm, more preferably 0.1 mm to 4 mm, and even more preferably 0.2 mm to 2 mm. Example 17: A heater assembly according to any of Examples 1 to 16, comprising wrapping material arranged around a microporous insulating foam. Example 18: The heater assembly according to Example 17, wherein the wrapping material is provided in the form of a film layer or film. Example 19: A heater assembly according to Example 17 or 18, wherein the wrapping material comprises one or more of the following: polyetheretherketone (PEEK), polyaryletherketone (PAEK), polyimide (PI), polyphenylsulfone (PPSU), polyethersulfone (PES), or polyetherimide (PEI). Example 20: A heater assembly according to any of Examples 1 to 19, further comprising aerogel. Example 21: The heater assembly described in Example 20, wherein the aerogel is a nanoporous aerogel. Example 22: A heater assembly according to any one of Examples 1 to 21, further comprising a first connecting wall connecting a heating chamber and a heater casing, and a second connecting wall connecting a heating chamber and a heater casing, wherein an airtight space is defined between the heating chamber, the heater casing, and the first and second connecting walls. Example 23: The heater assembly according to Example 22, wherein the connecting wall is oriented perpendicular to the longitudinal axis of the heating chamber. Example 24: A heater assembly as described in any of Examples 1 to 23, wherein the airtight space is at normal pressure. Example 25: A heater assembly according to any of Examples 1 to 24, wherein the airtight space is at least partially filled with microporous insulating foam. Example 26: A heater assembly according to any one of Examples 1 to 25, wherein the airtight space is at least partially filled with a gaseous composition at atmospheric pressure. Example 27: A heater assembly according to any of Examples 1 to 26, wherein the airtight space includes at least one void. Example 28: A heater assembly according to Example 27, wherein a microporous insulating foam is sandwiched radially between two voids. Example 29: A heater assembly according to any of Examples 1 to 28, wherein the microporous insulating foam is in direct contact with the heating chamber. Example 30: A heater assembly according to any of Examples 1 to 29, wherein the microporous insulation foam is in direct contact with the heater casing. Example 31: A heater assembly according to any one of Examples 1 to 30, wherein the microporous thermal insulation foam is in direct contact with the first and second connecting walls of claim 22. Example 32: A heater assembly according to any one of Examples 1 to 31, wherein the microporous insulating foam is in direct contact with the heating chamber, the heater casing, and the first and second connecting walls of claim 22. Example 33: A heater assembly according to any one of Examples 1 to 32, wherein the microporous thermal insulation foam is formed from at least one first thermal insulation element including at least one first connecting element and a second thermal insulation element including at least one second connecting element, and the first and second connecting elements are configured as matching connecting elements. Example 34: The heater assembly according to Example 33, wherein the first connecting element includes a male connecting element and the second connecting element includes a female connecting element. Example 35: The heater assembly according to Example 33 or 34, wherein the first and second connecting elements include morph-fitting connecting elements. Example 36: A heater assembly according to any one of Examples 33 to 35, wherein the first connecting element and the second connecting element include snap-fitting connecting elements. Example 37: A heater assembly according to any one of Examples 33 to 36, wherein the first and second connecting elements include bayonet connecting elements. Example 38: A heater assembly according to any of Examples 1 to 37, wherein the microporous thermal insulation foam has an elongated extension. Example 39: A heater assembly according to any of Examples 1 to 38, wherein the microporous insulating foam extends parallel to the longitudinal axis of the heating chamber. Example 40: A heater assembly according to any of Examples 1 to 39, wherein the distance between the heating chamber and the heater casing is 1.5 mm to 7 mm, preferably 2 mm to 4 mm, preferably about 3.1 mm. Example 41: A heater assembly according to any of Examples 1 to 40, further comprising a heating element. Example 42: The heater assembly according to Example 41, wherein the heating element is at least partially arranged around the heating chamber. Example 43: The heater assembly according to Example 41 or 42, wherein the microporous insulating foam has an extension in the longitudinal direction that is the same as or larger than the longitudinal extension of the heating element. Example 44: A heater assembly according to any one of Examples 41 to 43, wherein the heating element is flexible and is wrapped around the heating chamber. Example 45: A heater assembly according to any one of Examples 41 to 44, wherein the heating element is disposed between the heating chamber and the heater casing. Example 46: A heater assembly according to any one of Examples 41 to 45, wherein the heating element includes one or more conductive tracks on an electrically insulated substrate. Example 47: A heater assembly according to any one of Examples 1 to 46, wherein the ratio of the outer diameter of the heater casing to the outer diameter of the heating chamber is 1.3 to 3.5, preferably 1.5 to 2.5, and more preferably about 2.0. Example 48: A heater assembly according to any one of Examples 1 to 47, wherein the heating chamber has an elongated shape, and preferably the heating chamber is a hollow tube. Example 49: The heating chamber comprises a central region equipped with the heating element described in Example 41, Proximal region and, The distal region and, The proximal and distal regions are spaced apart from the heating element in the longitudinal direction. A heater assembly according to any of Examples 1 to 48, wherein the first connecting wall of Example 22 contacts the heating chamber in the proximal region, and the second connecting wall of Example 22 contacts the heating chamber in the distal region. Example 50: A heater assembly according to any of Examples 1 to 49, wherein the inside of the heater casing wall includes a metal coating, and optionally the wall of the heating chamber includes stainless steel. Example 51: A heater assembly according to any of Examples 1 to 50, wherein the thickness of the heater casing wall and one or more of the first and second connecting walls of claim 2 is less than 2 millimeters, preferably less than 1.2 millimeters, and more preferably about 0.8 millimeters. Example 52: A heater assembly according to any of Examples 1 to 51, wherein the airtight space includes a polyimide layer. Example 53: The heater assembly according to Example 52, wherein a polyimide layer is disposed around a microporous thermal insulation foam, preferably in direct contact with the microporous thermal insulation foam. Example 54: A heater assembly according to Example 53, wherein a gap is provided between the polyimide layer and the heater casing. Example 55: A heater assembly according to any of Examples 1 to 54, wherein a microporous insulating foam is disposed in direct contact with the heating chamber. Example 56: The heater assembly according to any one of Examples 1 to 55, further comprising a heat dissipation element disposed to at least partially surround a heating chamber, preferably the heat dissipation element being provided as a graphene layer, and more preferably the graphene layer being provided as a coating. Example 57: The heater assembly according to Example 56, wherein the heat dissipation element is disposed between the microporous insulating foam and the heating chamber, and on the outer periphery of the heating chamber. Example 58: An aerosol generator comprising a heater assembly described in any of Examples 1 to 57. Example 59: An aerosol generating system comprising the aerosol generating apparatus described in Example 58 and an aerosol-forming substrate configured to be at least partially received in a heating chamber, wherein the aerosol-forming substrate is a solid aerosol-forming substrate.

[0104] Features described in relation to one embodiment may be equally applicable to other embodiments of the present invention.

[0105] The present invention will be further explained with reference to the following attached drawings, which are for illustrative purposes only.

[0106] Figure 1 schematically shows a heater assembly 10. The heater assembly 10 comprises a heating chamber 12 for heating an aerosol-forming substrate. The heating chamber 12 has an elongated shape. The heating chamber 12 comprises heating chamber walls 14 surrounding a cavity for inserting the aerosol-forming substrate. The heating chamber walls 14 form a hollow tube. The heater assembly 10 further comprises a heater casing. The heater casing is arranged coaxially around the heating chamber 12. The heater casing comprises a cylindrical wall of heater casing 16. The heater casing is further arranged at a radial distance d from the heating chamber 12. The distance d is measured radially between the outer diameter of the hollow tube formed by the heating chamber walls 14 and the inner diameter of the cylindrical wall of heater casing 16. The heating chamber walls 14 and the walls of heater casing 16 have a matching shape. Thereafter, the distance d is constant along the longitudinal axis of the heating chamber 12.

[0107] The heater assembly 10 further comprises a first connecting wall 18 at its proximal end. The heater assembly 10 further comprises a second connecting wall 20 at its distal end. The first and second connecting walls 18 and 20 are oriented perpendicular to the longitudinal axis of the heating chamber 12. The heater assembly 10 further comprises an airtight space 22. The airtight space 22 is defined between the heating chamber wall 14, the heater casing wall 16, and the first and second connecting walls 18 and 20. The airtight space 22 contains microporous thermal insulation foam.

[0108] Figure 2 shows one embodiment of the heating chamber 12. The heating chamber 12 comprises a central region containing a heating element. The heating element is partially arranged around the heating chamber 12. The walls of the heating chamber 14 are metal tubing, preferably stainless steel tubing. The heating element is flexible and wound around the metal tubing. The heating element comprises a conductive heating track 24 on an electrically insulated flexible substrate 26. In the shown embodiment, the proximal and distal edges of the flexible substrate 26 are not covered by the heating track 24. In other embodiments, different regions of the flexible substrate 26, or even the entire surface, may be covered by the heating track 24. The proximal region 28 and distal region 30 of the heating chamber 12 are spaced apart from the heating element in the longitudinal direction.

[0109] Figure 3 shows one embodiment of the heater assembly 10, which includes the heating chamber 12 shown in Figure 2. The heating element is disposed between the heating chamber 12 and the heater casing.

[0110] The first and second connecting walls 18 and 20 seally connect the heater casing wall 16 to the heating chamber wall 14, thereby sealing the airtight space 22.

[0111] The first and second connecting walls 18 and 20 contact the heating chamber 12 in the proximal region 28 and the distal region 30, respectively. The first and second connecting walls 18 and 20 contact the heating chamber 12 at a distance from the heating element. Therefore, when heated during use, the first and second connecting walls 18 and 20 contact the heating chamber at its coldest point 12. This further reduces heat loss due to heat transfer from the heating chamber 12 to the connecting walls 18 and 20 and the heater casing by heat conduction. Insulation can be further improved.

[0112] The airtight space 22 includes a microporous insulating foam 32.

[0113] The microporous thermal insulation foam 32 may be, for example, a polymer microporous thermal insulation foam. The microporous thermal insulation foam 32 may include one or more of the following: polyaryletherketone (PAEK) foam, polyamide 46 (PA46) foam, polyamide 4T (PA4T) foam, polyphenylsulfone (PPSU) foam, polyethersulfone (PES) foam, and polyetherimide (PEI) foam. The microporous thermal insulation foam 32 may include or consist of polyaryletherketone (PAEK) foam. The polyaryletherketone (PAEK) foam may include or consist of one or more of the following: polyetherketone (PEK) foam, polyetheretherketone (PEEK) foam, polyetherketoneketone (PEKK) foam, polyetheretherketoneketone (PEEKK) foam, and polyetherketoneetherketoneketone (PEKEKK) foam. Polyaryl ether ketone (PAEK) forms may contain ether-to-ketone ratios of approximately 2:1, 1:1, 2:3, or 1:2.

[0114] In the embodiment shown in Figure 3, the entire airtight space 22 is filled with microporous thermal insulation foam 32. The microporous thermal insulation foam 32 is in contact with the heating chamber wall 14, the heating track 24, the first and second connecting walls 18 and 20, and the heater casing wall 16. Although not shown, the microporous thermal insulation foam 32 shown in Figure 3 may also include one or more voids extending in a direction parallel to the longitudinal axis of the aerosol generator. These voids may be in direct contact with the heating chamber wall 14, the heater casing wall 16, or the first and second connecting walls 18, 20. These voids may have longitudinal extensions shorter than the microporous thermal insulation foam 32.

[0115] Figures 4, 5, and 6 show alternative embodiments in which the airtight space 22 is only partially filled with microporous insulation foam 32. The main elements are similar to those of the heater assembly in Figure 3. In the embodiments shown in Figures 4, 5, and 6, the airtight space 22 includes at least one additional void 34. In all of these embodiments, the microporous insulation foam 32 is in contact with the first connecting wall 18 and the second connecting wall 20. However, the microporous insulation foam 32 may alternatively be in contact with only one of the first and second connecting walls 18, 20. Preferably, the microporous insulation foam 32 is in contact with only the first (proximal) connecting wall 18. The microporous insulation foam 32 can be mounted on the first connecting wall 18 and the second connecting wall 20.

[0116] Figure 4 shows a heater assembly in which a void 34 extends around the heating chamber 12. The microporous insulating foam 32 extends around the void 34, which is radially spaced away from the heating chamber 12. The microporous insulating foam 32 is in direct contact with the wall 16 of the heater casing.

[0117] Figure 5 shows an alternative embodiment in which the microporous insulating foam 32 is in direct contact with the heating chamber 12. The voids 34 extend around the microporous insulating foam 32, radially spaced away from the heating chamber 12. The voids 34 are in direct contact with the wall 16 of the heater casing.

[0118] Figure 6 shows an alternative embodiment in which the airtight space 22 includes two voids 34. One void 34 extends around the heating chamber 12 and is directly connected to the heating chamber 12. Microporous insulation foam 32 extends radially away from this void 34. Subsequently, an additional void 34 extends around the microporous insulation foam 32, radially spaced away from it. The microporous insulation foam 32 is radially sandwiched between the two voids 34.

[0119] The airtight spaces 22 shown in Figures 3, 4, 5, and 6 can be filled with microporous thermal insulation foam 32 in different proportions. For example, half the volume of the airtight space 22 can be filled with microporous thermal insulation foam 32. However, other proportions are also possible. For example, 20, 30, 40, 50, 60, 70, 80, or 90 volume percent of the airtight space 22 can be filled with microporous thermal insulation foam 32.

[0120] Figure 7 shows a two-part assembly of the microporous thermal insulation foam 32. All heater assemblies 10 illustrated in Figures 3, 4, 5, and 6 can also comprise the two-part assembly of Figure 7. However, the two-part assembly is particularly suitable for the embodiments of Figures 3 and 5. As can be seen in Figure 7, the microporous thermal insulation foam 32 is formed from a first thermal insulation element 36 having a first connecting element 40, and a second thermal insulation element 38 having a second connecting element 42. The first connecting element 40 and the second connecting element 42 are configured as matching connecting elements. When the two first thermal insulation elements 36 and the second thermal insulation element 38 are connected, the first connecting element 40 and the second connecting element 42 are connected to each other. The connection of the first connecting element 40 and the second connecting element 42 provides direct contact between the first thermal insulation element 36 and the second thermal insulation element 38. The first thermal insulation element 36 and the second thermal insulation element 38 can have a hollow semi-cylindrical design, as shown in Figure 7. However, other shapes and configurations are also possible. When connected, the hollow semi-cylindrical design provides a hollow tube. The hollow tube may have an inner diameter substantially identical to the outer diameter of the heating chamber 12. The hollow tube may have an inner diameter identical to the combined outer diameter of the heating chamber 12 and the heating track 24. This two-part assembly allows the microporous insulation foam 32 to have a complete fit with the heating chamber 12 and the heating track 24 surrounding the heating chamber. Furthermore, if the heating chamber includes a temperature sensor (not shown), the inner shape of the microporous insulation foam 32 can be configured to fit the temperature sensor. The microporous insulation foam 32 may include a cavity facing the sensor. The cavity may have the same volume and inverse shape as the temperature sensor. The microporous insulation foam 32 can completely enclose the heating chamber 12 and the heating track 24. Using a hollow tube consisting of only a single element of the microporous insulation foam 32 may not provide such a complete fit with the heating chamber 12.

[0121] Figure 8 shows one embodiment of an aerosol generator comprising the heater assembly 10 of Figure 3. The aerosol generator further comprises a power source. The power source includes a power supply 44 and control electronic equipment 46. The power supply 44 may be a rechargeable battery. In the embodiment of Figure 8, the wall 16 of the heater casing forms part of the outer housing 48 of the aerosol generator.

[0122] At the opening 50, the aerosol-forming substrate can be at least partially inserted into the heating chamber 12. The aerosol-forming substrate may also be part of the aerosol-generating article.

[0123] Figure 9 shows one embodiment of an aerosol generator equipped with the heater assembly 10 shown in Figure 3. Unlike the embodiment in Figure 8, in the embodiment of Figure 9, the heater assembly 10 is housed in a separate outer housing 48 of the aerosol generator.

[0124] Figure 10 shows one embodiment of an aerosol generator, including a heater assembly 10 positioned adjacent to the proximal end of the aerosol generator. The flexible substrate 26 and heating track 24 of the heating assembly 10 are arranged around the heating chamber 12. Microporous thermal insulation foam 32 is arranged around and in contact with the flexible substrate 26 and heating track 24. The microporous thermal insulation foam 32 may contain 1% to 99% aerogel and up to 30% polymer resin. The microporous thermal insulation foam 32 is provided as a flexible layer by providing the polymer resin so that the microporous thermal insulation foam 32 can be wound around the flexible substrate 26 on the heating track 24. A polyimide layer 52 is arranged to surround the microporous thermal insulation foam 32 in order to hold the microporous thermal insulation foam 32 in place. The polyimide layer 52a is a flexible layer. The polyimide layer 52 may partially cover the microporous thermal insulation foam 32, as shown in Figure 10. In the embodiment shown in Figure 10, a proximal overlap is provided between the polyimide layer 52 and the microporous thermal insulation foam 32. In other words, the microporous thermal insulation foam 32 extends proximal beyond the polyimide layer 52. Similarly, a distal overlap is provided between the polyimide layer 52 and the microporous thermal insulation foam 32 so that the microporous thermal insulation foam 32 extends distally beyond the polyimide layer 52. Alternatively, the polyimide layer 52 may completely cover the microporous thermal insulation foam 32.

[0125] A void 54 is provided surrounding the polyimide layer 52. The polyimide layer 52 and the void 54 are located within an airtight space 22. The wall of the heater casing 16 is provided radially outward of the void 54.

[0126] The microporous insulation foam 32 is in direct contact with the first connecting wall 18 located proximal to the microporous insulation foam 32. The microporous insulation foam 32 is at a distance from the second connecting wall 20 located distal to the microporous insulation foam 32. Alternatively, the microporous insulation foam 32 may be at a distance from the first connecting wall 18 as well. As a further alternative, the microporous insulation foam 32 may be in direct contact with both the first connecting wall 18 and the second connecting wall 20.

[0127] In the embodiment shown in Figure 10, the walls of the heater casing, more specifically the heater casing 16, are attached to an inner frame 56 within the housing 48 of the aerosol generator. The inner frame 56 may hold further components of the aerosol generator, such as the heating chamber 12.

Claims

1. A heater assembly for an aerosol generator, A heating chamber for heating the aerosol-forming substrate, A heater assembly comprising: a heater casing disposed around the heating chamber, disposed radially apart from the heating chamber, the heater casing including an airtight space, and the airtight space including a microporous insulating foam.

2. The heater assembly according to claim 1, wherein the microporous insulating foam is a polymer microporous insulating foam.

3. The heater assembly according to claim 2, wherein the microporous insulating foam comprises one or more of the following: polyaryletherketone (PAEK) foam, polyamide 46 (PA46) foam, polyamide 4T (PA4T) foam, polyphenylsulfone (PPSU) foam, polyethersulfone (PES) foam, and polyetherimide (PEI) foam.

4. The heater assembly according to claim 3, wherein the microporous insulating foam includes polyaryletherketone (PAEK) foam.

5. The heater assembly according to claim 4, wherein the polyaryletherketone (PAEK) foam comprises one or more of the following: polyetherketone (PEK) foam, polyetheretherketone (PEEK) foam, polyetherketoneketone (PEKK) foam, polyetheretherketoneketone (PEEKK) foam, and polyetherketoneetherketoneketone (PEKEKK) foam.

6. The heater assembly according to claim 4 or 5, wherein the polyaryletherketone (PAEK) foam comprises an ether-to-ketone ratio of about 2:1, about 1:1, about 2:3, or about 1:

2.

7. The heater assembly according to any one of claims 1 to 6, wherein the average pore size of the microporous heat insulating foam is 1 micrometer to 500 micrometers, preferably 1 micrometer to 300 micrometers, more preferably 1 micrometer to 100 micrometers, and more preferably 1 micrometer to 50 micrometers.

8. The heater assembly according to any one of claims 1 to 7, wherein the microporous thermal insulation foam is made of a material that can withstand temperatures of at least 100 degrees Celsius, preferably at least 200 degrees Celsius, more preferably 100 to 500 degrees Celsius, more preferably 150 to 400 degrees Celsius, and more preferably 200 to 300 degrees Celsius without substantial degradation.

9. The microporous insulating foam has a thermal conductivity of less than 0.05 W / m·K, preferably less than 0.04 W / m·K, more preferably less than 0.03 W / m·K, at room temperature, and / or The heater assembly according to any one of claims 1 to 8, wherein the microporous insulating foam has a thermal conductivity of less than 0.05 W / m·K, preferably less than 0.04 W / m·K, and more preferably less than 0.03 W / m·K at a temperature of 280 degrees Celsius.

10. The heater assembly according to any one of claims 1 to 9, wherein the microporous thermal insulation foam has a glass transition temperature of 100 degrees Celsius to 250 degrees Celsius, preferably 105 degrees Celsius to 235 degrees Celsius, more preferably 110 degrees Celsius to 230 degrees Celsius.

11. The heater assembly according to any one of claims 1 to 10, wherein the microporous heat insulating foam has a melting point of 250 degrees Celsius to 450 degrees Celsius, preferably 280 degrees Celsius to 400 degrees Celsius, and more preferably 280 degrees Celsius to 350 degrees Celsius.

12. The heater assembly according to any one of claims 1 to 11, wherein the microporous thermal insulation foam has a density of less than 700 kilograms / cubic meter, preferably less than 600 kilograms / cubic meter, and more preferably less than 500 kilograms / cubic meter.

13. The heater assembly according to any one of claims 1 to 12, wherein the microporous insulating foam forms a single insulating layer, and the insulating layer has a thickness of 0.005 mm to 10 mm, preferably 0.01 mm to 5 mm, more preferably 0.1 mm to 4 mm, and even more preferably 0.2 mm to 2 mm.

14. An aerosol generator comprising a heater assembly according to any one of claims 1 to 13.

15. An aerosol generating system comprising an aerosol generating device according to claim 14 and an aerosol-forming substrate configured to be at least partially received in the heating chamber, wherein the aerosol-forming substrate is a solid aerosol-forming substrate.

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