Heater assembly with shielded microporous insulation

Abstract

The present invention relates to a heater assembly (12) for an aerosol generating device. The aerosol generating device includes a heating chamber (18) for heating an aerosol-forming substrate. The aerosol generating device includes a heater casing (22) disposed around the heating chamber (18). The heater casing (22) is disposed radially spaced from the heating chamber (18). The heater casing (22) includes an airtight space. The airtight space includes a microporous insulating material (38). The airtight space includes a shielding element. The shielding element is configured to cover at least a portion of the microporous insulating material (38).

Description

[Technical Field]

[0001] The present invention relates to a heater assembly.The present invention relates to an aerosol generating device.The present invention relates to an aerosol generating system.The present invention relates to a method for manufacturing a heater assembly. [Background technology]

[0002] It is known to provide an aerosol-generating device for generating an inhalable vapor. Such a device can heat an aerosol-forming substrate to a temperature at which one or more components of the aerosol-forming substrate volatilize without burning the aerosol-forming substrate. The aerosol-forming substrate may be provided as part of an aerosol-generating article. The aerosol-generating article may have a rod shape for insertion of the aerosol-generating article into a cavity (such as a heating chamber) of the aerosol-generating device. A heating element may be disposed in or around the heating chamber for heating the aerosol-forming substrate once the aerosol-generating article is inserted into the heating chamber of the aerosol-generating device.

[0003] It would be desirable to provide an aerosol generating device that can reduce heat loss from the heating chamber. It would be desirable to insulate the heating chamber from other components of the aerosol generating device. It would be desirable to have an aerosol generating device that can reduce heating of the outer housing of the device held by the user. It would be desirable to have an aerosol generating device that can provide effective insulation. It would be desirable to have an aerosol generating device that can provide insulation at low manufacturing costs. It would be desirable to have an aerosol generating device that can have improved insulation. It would be desirable to have an aerosol generating device that can have more compact device dimensions. It would be desirable to provide an aerosol generating device that consumes reduced power. It would be desirable to provide an aerosol generating device that reduces the risk of contamination of the heating chamber and other components of the aerosol generating device. It would be desirable to provide a simplified method of manufacturing a heater assembly. Summary of the Invention

[0004] According to one embodiment of the present invention, there is provided a heater assembly for an aerosol-generating device. The heater assembly may include a heating chamber for heating an aerosol-forming substrate. The heater assembly may further include a heater casing disposed around the heating chamber. The heater casing may be disposed radially spaced from the heating chamber. The heater casing may include an airtight space. The airtight space may include a microporous insulating material. The airtight space may include a shielding element. The shielding element may be configured to cover at least a portion of the microporous insulating material. [Brief explanation of the drawings]

[0005] [Figure 1] 1 shows an aerosol generating device comprising a heater assembly of the present invention. [Figure 2] 1 illustrates the production of a shielded microporous insulating material using a shielding element comprising a film. [Figure 3] 3 shows the resulting shielded microporous insulating material using the film of FIG. 2 in a heater assembly. [Figure 4] 10 illustrates the production of a shielded microporous insulating material using a shielding element comprising a further embodiment of a film. [Figure 5] 5 shows the resulting shielded microporous insulating material using the film of FIG. 4 in a heater assembly. DETAILED DESCRIPTION OF THE INVENTION

[0006] The invention will now be further described, by way of example only, with reference to the accompanying drawings in which:

[0007] 1 shows one embodiment of an aerosol generating device 10 (shielding element not shown) comprising a heater assembly 12 of the present invention. The aerosol generating device 10 comprises a power source. The power supply comprises a power source 14 and control electronics 16. The power source 14 may be a rechargeable battery.

[0008] The heater assembly 12 includes a heating chamber 18 for heating an aerosol-forming substrate. The heating chamber 18 has an elongated shape. The heating chamber 18 includes a heating chamber wall 20 that encloses a cavity for insertion of the aerosol-forming substrate. The heating chamber wall 20 forms a hollow tube. The heater assembly 12 further includes a heater casing 22. The heater casing 22 is disposed coaxially around the heating chamber 18. The heater casing 22 includes a cylindrical wall 24 of the heater casing 22. The heater casing 22 is further disposed radially spaced a distance d from the heating chamber 18. The distance d is measured radially between the outer diameter of the hollow tube formed by the wall 20 of the heating chamber 18 and the inner diameter of the cylindrical wall 24 of the heater casing 22. The wall 20 of the heating chamber 18 and the wall 24 of the heater casing 22 have matching shapes. Thereby, the distance d is constant along the longitudinal axis of the heating chamber 18.

[0009] The heater assembly 12 further comprises a first connecting wall 26 at a proximal end of the heater assembly 12. The heater assembly 12 further comprises a second connecting wall 28 at a distal end of the heater assembly 12. The first connecting wall 26 and the second connecting wall 28 are oriented perpendicular to the longitudinal axis of the heating chamber 18. The heater assembly 12 further comprises an airtight space. The airtight space is defined between the wall 20 of the heating chamber 18, the wall 24 of the heater casing 22, and the first connecting wall 26 and the second connecting wall 28.

[0010] The heating chamber 18 includes a central region that includes a heating element. The heating element is disposed partially around the heating chamber 18. The wall 20 of the heating chamber 18 is a metal tube. The heating element is flexible and wrapped around the metal tube. The heating element includes an electrically conductive heating track 30 on an electrically insulated flexible substrate 32. In the illustrated embodiment, the proximal and distal edge portions of the flexible substrate 32 are not covered by the heating track 30. In other embodiments, different regions of the flexible substrate 32, or even the entire surface, may be covered by the heating track 30. The proximal and distal regions 34 and 36 of the heating chamber 18 are longitudinally spaced from the heating element. The heating element is disposed between the heating chamber 18 and the heater casing 22.

[0011] First and second connecting walls 26, 28 sealingly connect the wall 24 of the heater casing 22 with the wall 20 of the heating chamber 18, thereby airtightly enclosing an airtight space.

[0012] The airtight space contains a microporous insulating material 38 (shielding element not shown), which may be, for example, MICROSIL microporous insulation from ZIRCAR Ceramics, Inc., Excelfrax® from Unifrax I LLC, Microtherm 1000 grade from Promat Inc, or other commercially available microporous insulating material. The microporous insulating material 38 is covered with a shielding element (not shown).

[0013] In the embodiment shown in Figure 1, the entire airtight space is filled with microporous insulating material 38. A shielding element covering the microporous insulating material 38 is in contact with the wall 20 of the heating chamber 18, the heating track 30, the first and second connecting walls 26 and 28, and the wall 24 of the heater casing 22. Although not shown, the microporous insulating material 38 shown in Figure 1 may also include one or more voids extending in a direction parallel to the longitudinal axis of the aerosol generating device. These voids may be in direct contact with the wall 20 of the heating chamber 18, the wall 24 of the heater casing 22, or the first and second connecting walls 26, 28. These voids may have a shorter longitudinal extension than the microporous insulating material 38.

[0014] 2 illustrates the manufacture of a shielded microporous insulating material 38. The shielding element comprises a film 40. The film 40 is wrapped around the microporous insulating material 38 to form the shielding element.

[0015] The film 40 has a cross shape. The film 40 has four arms 42, 44, 46, and 48. The arms 42, 44, 46, and 48 are arranged around a central portion 50 of the film 40. The central portion 50 of the film 40 is indicated by a dashed line. The central portion 50 of the film 40 is rectangular. Each arm 42, 44, 46, and 48 is arranged along an edge of the central portion 50 of the film 40.

[0016] Arms 42 and 46 are disposed opposite each other. Arms 42 and 46 are disposed along opposite edges of central portion 50. Arms 42 and 46 are configured to be identical. Arms 42 and 46 have the same shape. Arms 42 and 46 have the same length. Arms 42 and 46 have the same width. Arms 42 and 46 have the same thickness. Arm 42 has a rectangular shape. Arm 46 has a rectangular shape. The length of arms 42 and 46 corresponds to the length of central portion 50.

[0017] Arms 44 and 48 are disposed opposite each other. Arms 44 and 48 are disposed along opposite edges of central portion 50. Arms 44 and 48 are configured differently from each other. Arm 48 is shorter than arm 44. Arm 44 is elongated compared to arm 48. Arm 44 has a rectangular shape. Arm 48 has a rectangular shape. The widths of arms 44 and 48 correspond to the width of the central portion.

[0018] The central portion 50 of the film 40 has a rectangular shape. The length of the central portion 50 corresponds to the length of the arms 42 and 46. The width of the central portion 50 corresponds to the width of the arms 44 and 48. The central portion 50 is configured to match the shape of the microporous insulating material 38.

[0019] The microporous insulation material 38 may be attached to the film 40 with an adhesive. The film 40 may at least partially cover the microporous insulation material 38 to form a shielded microporous insulation material 38. The adhesive may be applied to at least a portion of the central portion 50. The microporous insulation material 38 may be attached to the film 40 via adhesive applied to the central portion 50. The adhesive may be applied to at least a portion of one or more of the arms 42, 44, 46, and 48. The arms 42, 46, and 48 may be folded over at least a portion of the microporous insulation material 38 attached to the film 40 to at least partially enclose the microporous insulation material 38. The arms 42, 46, and 48 may be attached to the microporous insulation material 38 via adhesive applied to the arms 42, 46, and 48. The at least partially enclosed microporous insulation material 38 may be wrapped around the heating chamber 18 of the heater assembly 12. The elongated arms 44 may be wrapped around the at least partially enclosed microporous insulation material 38 to attach the microporous insulation material to the exterior surface of the heating chamber 18. The shielded microporous insulation material 38 is configured to conform to the shape of the heating chamber 18. The film 40 covers the entire microporous insulation material 38. The shielded microporous insulation material 38 with the film shielding element of FIG. 2 can be easy and cost-effective to manufacture.

[0020] 3A shows a shielded microporous insulating material 38 having the film of FIG. 2 secured around a heating chamber 18. The heating chamber 18 is configured as a metal tube. The heating chamber 18 includes a central cavity 52. ​​The cavity 52 is configured to receive an aerosol-forming substrate. The heating chamber 18 has a circular cross-section.

[0021] FIG. 3B shows a schematic cross-sectional view of the heater assembly 12 including the heating chamber 18 and shielded microporous insulation material 38 of FIG. 3A. The heating chamber 18 is centrally disposed. The shielded microporous insulation material 38 is disposed radially outward of the heating chamber 18. The shielded microporous insulation material 38 is coaxially aligned around the heating chamber 18. The shielded microporous insulation material 38 surrounds the heating chamber 18. A film 40 of the shielded microporous insulation material 38 is in contact with the heating chamber 18. A void 54 is disposed radially outward of the shielded microporous insulation material 38. The void 54 is coaxially aligned around the shielded microporous insulation material 38. The void 54 surrounds the shielded microporous insulation material 38. The heater casing 22 is disposed radially outward of the void 54. The heater casing 22 is coaxially aligned around the cavity 54. The heater casing 22 surrounds the cavity 54. A heating element (not shown) may be disposed around the heating chamber 18. The heating element may be disposed between the heating chamber 18 and the shielded microporous insulation material 38. If a heating element is present, the film 40 of the shielded microporous insulation material 38 may contact the heating element.

[0022] FIG. 4 illustrates the fabrication of a shielded microporous insulation material 38 using another embodiment of film 40. The notes regarding FIG. 2 equally apply to film 40 in FIG. 4. However, in contrast to film 40 in FIG. 2, arms 44 and 48 of film 40 in FIG. 4 are configured identically. Film 40 in FIG. 4 has a symmetrical cross shape. Adhesive may be applied to at least a portion of central portion 50 of film 40. Microporous insulation material 38 may be attached to film 40 via adhesive. Adhesive may be applied to at least a portion of one or more of arms 42, 44, 46, and 48. Arms 42, 44, 46, and 48 may be folded over microporous insulation material 38 attached to film 40 to completely enclose microporous insulation material 38. Arms 42, 44, 46, and 48 may be attached to microporous insulation material 38 via adhesive applied to arms 42, 44, 46, and 48. The film 40 completely covers the microporous insulation material 38 to form the shielded microporous insulation material 38. The shielded microporous insulation material 38 may be inserted into the heater casing 22.

[0023] Figure 5A shows the shielded microporous insulation material 38 with the film of Figure 4 inserted into heater casing 22. The film 40 of shielded microporous insulation material 38 contacts the interior surface of heater casing 22. Heating chamber 18 (not shown in Figure 5A) can be inserted into shielded microporous insulation material 38.

[0024] 5B shows a schematic cross-sectional view of a heater assembly 12 including a shielded microporous insulation material 38 with the film shielding element of FIG. 4. The heating chamber 18 is centrally disposed around a cavity 52. ​​The cavity 52 is configured to receive an aerosol-forming substrate. A gap 54 is disposed radially outward of the heating chamber 18. The gap 54 is coaxially aligned around the heating chamber 18. The shielded microporous insulation material 38 is disposed radially outward of the gap 54. The shielded microporous insulation material 38 is coaxially aligned around the gap 54. The heater casing 22 is disposed radially outward of the shielded microporous insulation material 38. The heater casing 22 is coaxially aligned around the shielded microporous insulation material 38. The shielded microporous insulation material 38 is disposed against the heater casing 22. Shielded microporous insulating material 38 is disposed in contact with heater casing 22. A heating element (not shown) may be disposed around heating chamber 18. The heating element may be disposed between heating chamber 18 and air gap 54.

[0025] According to one embodiment of the present invention, there is provided a heater assembly for an aerosol-generating device. The heater assembly includes a heating chamber for heating an aerosol-forming substrate. The heater assembly includes a heater casing disposed around the heating chamber. The heater casing is disposed radially spaced from the heating chamber. The heater casing includes an airtight space. The airtight space includes a microporous insulating material. The airtight space includes a shielding element. The shielding element is configured to cover at least a portion of the microporous insulating material.

[0026] The aerosol generating device may have reduced heat loss from the heating chamber. The heating chamber may be insulated from other components of the aerosol generating device. The aerosol generating device may provide reduced heating of an outer housing of the device held by a user. The aerosol generating device may provide effective thermal insulation. The aerosol generating device may provide thermal insulation at a low manufacturing cost. The aerosol generating device may have improved thermal insulation. The aerosol generating device may have more compact device dimensions. The aerosol generating device may have reduced power consumption. The aerosol generating device may provide a reduced risk of contamination of the heating chamber and other components of the aerosol generating device. The manufacturing method of the heater assembly may be easier. The shielded microporous insulating material may reduce heat loss from the aerosol generating device. The shielded microporous insulating material may reduce heating of an outer housing of the device held by a user. The shielded microporous insulating material may provide effective thermal insulation. The shielded microporous insulating material may provide thermal insulation at a low cost. The shielded microporous insulating material may reduce the risk of contamination of the heating chamber and other components of the aerosol generating device.

[0027] The shielding element may be configured to completely cover the microporous insulating material. The shielding element may be disposed within the airtight space. The shielding element may be completely disposed within the airtight space.

[0028] The shielding element may be configured to separate the microporous insulating material from other components of the heater assembly. The shielding element may be configured to separate the microporous insulating material from other components of the aerosol generating device. The shielding element may be configured to separate the microporous insulating material from the heater casing. The shielding element may be configured to separate the microporous insulating material from the heating chamber. The shielding element may be configured to separate the microporous insulating material from the heating element. The shielding element may be configured to contain a loose portion of the microporous insulating material in a space separated from other components of the heater assembly.

[0029] The shielding element may be disposed between the microporous insulating material and the heater casing. The shielding element may be disposed between the microporous insulating material and the heating chamber. The shielding element may be disposed between the microporous insulating material and the heating element.

[0030] The shielding element may reduce the risk of contamination of one or more of the heater casing, heating chamber, and heating element by loose portions of the microporous insulation material. The shielding element may prevent portions of the microporous insulation material from contacting other components of the heater assembly. The shielding element may be configured as a barrier between the microporous insulation material and other components of the heater assembly. The shielding element may be configured to trap unwanted debris within the shielding element.

[0031] The shielding element may be made of a non-porous material. The shielding element may be made of a solid material. The shielding element may be configured to be impermeable to loose portions of the microporous insulating material. The shielding element may be configured to be impermeable to dust particles of the microporous insulating material.

[0032] The heater casing may include a compartment configured to hold the microporous insulating material. The compartment may be at least partially formed from a shielding element. The shielding element may include at least one partition wall. The shielding element may include two partition walls. The partition wall may be disposed between the microporous insulating material and the heating chamber. The partition wall may be disposed between the microporous insulating material and at least a portion of the heater casing. The partition wall may be disposed between the microporous insulating material and the heating element. The compartment may be disposed within the airtight space. The partition wall may be disposed within the airtight space. The partition wall may be configured to divide the airtight space into at least two separate regions. Fluid communication between the at least two separate regions may be blocked by the partition wall. The two partition walls may be configured to divide the airtight base into three separate regions. Fluid communication between the three separate regions may be blocked by the two partition walls. The compartment configured to hold the microporous insulating material can be one of the regions. The compartment configured to hold the microporous insulating material can be a centrally disposed region. The divider wall can be configured to be impermeable to loose particles of the microporous insulating material.

[0033] The shielding element may have a circular cross-section. The shielding element may have an elliptical or oval cross-section. The shielding element may have a rectangular cross-section. The shape of the shielding element may match the shape of the microporous insulating material. The shielding element may be cylindrical. The shielding element may have a hollow tubular shape. The shielding element may have an elongated ring shape.

[0034] A microporous insulating material covered by a shielding element may be referred to as a "shielded microporous insulating material." A microporous insulating material at least partially covered by a shielding element may be referred to as a "shielded microporous insulating material." The term "shielded microporous insulating material" may refer to a microporous insulating material that is at least partially surrounded by a film. The term "shielded microporous insulating material" may refer to a microporous insulating material that is completely surrounded by a film. The term "shielded microporous insulating material" may refer to a microporous insulating material that is at least partially surrounded by a covering. The term "shielded microporous insulating material" may refer to a microporous insulating material that is completely surrounded by a covering.

[0035] The shielding element may extend in a direction parallel to the longitudinal axis of the aerosol generating device.

[0036] The shielding element may include a cavity. The shielding element may enclose the cavity. The cavity of the shielding element may be configured to hold the microporous insulating material. The shape of the microporous insulating material may match the shape of the cavity. The shape of the microporous insulating material may closely match the shape of the cavity. The cavity may be separated from the heating element. The cavity may be separated from the heating chamber. The shielding element may be a hollow ring. The shielding element may be an elongated hollow ring. The cavity may be sealed from other components of the heater assembly.

[0037] The shielding element may include an outer wall. The shielding element may include an inner wall. The outer wall of the shielding element may surround the inner wall of the shielding element. The shielding element may include a first intermediate wall. The first intermediate wall of the shielding element may be a proximal intermediate wall. The first intermediate wall may connect the inner and outer walls of the shielding element. The shielding element may include a second intermediate wall. The second intermediate wall of the shielding element may be a distal intermediate wall. The second intermediate wall may connect the inner and outer walls of the shielding element. The first intermediate wall and the second intermediate wall may be disposed at opposite ends of the shielding element.

[0038] The outer wall, inner wall, first intermediate wall, and second intermediate wall of the shielding element may enclose a cavity of the shielding element. The outer wall, inner wall, first intermediate wall, and second intermediate wall of the shielding element may enclose a microporous insulating material. The outer wall of the shielding element may be disposed adjacent to the heater casing. The inner wall of the shielding element may be disposed adjacent to the heating chamber. The inner wall of the shielding element may be disposed adjacent to the heating element. The outer wall of the shielding element may abut the heater casing. The inner wall of the shielding element may abut the heating chamber. The inner wall of the shielding element may abut the heating element. The cavity of the shielding element may be separated from other components of the heater assembly by one or more of the outer wall, inner wall, first intermediate wall, and second intermediate wall of the shielding element.

[0039] The shape of the shielding element may match the shape of the heater casing. The shape of the shielding element may match the shape of the heating chamber. The shielding element may be coaxially aligned around the heating chamber. The heater casing may be coaxially aligned around the shielding element. The heater casing may be coaxially aligned around the microporous insulating material. The microporous insulating material may be coaxially aligned around the heating chamber. The shielding element may be coaxially aligned around the heating element.

[0040] The interruption may be disposed along at least a portion of the longitudinal axis of the heating chamber.

[0041] The shielding element may be made of a low thermal conductivity material. The microporous insulating material may be a low thermal conductivity material. Heat loss from the heating chamber may be reduced.

[0042] The "operating temperature" may depend on the type of aerosol-generating device and the aerosol-forming substrate used. The operating temperature of the aerosol-generating device may range from 150 to 300 degrees Celsius. The operating temperature of the aerosol-generating device may range from 200 to 230 degrees Celsius. The operating temperature of the aerosol-generating device may not exceed 280 degrees Celsius.

[0043] The airtight hollow space may contain air as an insulating material. However, the thermal conductivity of air may increase as the temperature increases. The microporous insulating material may contain small cavities or pores. Because air or other gaseous compositions are trapped within these cavities, the thermal conductivity of the microporous insulating material decreases as the temperature increases, compared to air. The microporous insulating material may maintain its thermal conductivity at approximately the operating temperature of the aerosol generating device, compared to its thermal conductivity at room temperature. The low thermal conductivity of the microporous insulating material may result in better insulation.

[0044] Due to better insulation, a heater casing including a microporous insulating material can have a reduced outer diameter. By providing a heater casing with an airtight space including a microporous insulating material, an aerosol generating device can be obtained that can have more compact device dimensions.

[0045] As used herein, the terms "upstream" and "downstream" are used to indicate the relative location of components or portions of components of an aerosol-generating device with respect to the direction of airflow through the aerosol-generating device during use. An aerosol-generating device according to the present invention has a proximal end through which aerosol exits the device during use. The proximal end of an 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 an 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.

[0046] The proximal end of the heater assembly of the present invention may be configured to be disposed within the aerosol generating device in a direction toward the mouth or downstream end of the device. The distal end of the heater assembly of the present invention may be configured to be disposed within the aerosol generating device in a direction toward the distal or upstream end of the device. The longitudinal axis of the heating chamber may extend between the proximal end of the heating chamber and the distal end of the heating chamber. The longitudinal axis of the heating chamber may extend between the proximal end of the heater assembly and the distal end of the heater assembly.

[0047] The heating chamber may be configured to at least partially receive the aerosol-forming substrate. The heating chamber may comprise a cavity into which the aerosol-forming substrate may be inserted. The aerosol-forming substrate may be part of an aerosol-generating article. The cavity may have a shape corresponding to the shape of the aerosol-generating article to be received therein. 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.

[0048] The heating chamber may comprise an opening at the proximal end thereof for receiving the aerosol-forming substrate. The opening may also serve as an air outlet. The heating chamber may comprise an air inlet at the distal end thereof.

[0049] The heating chamber may have an elongated shape. The heating chamber may be a hollow tube. The hollow tube may be formed from the walls of the heating chamber. The walls of the heating chamber may include or be made of a metal or alloy. The walls of the heating chamber may include or be made of stainless steel.

[0050] The heater casing may be radially spaced a distance d from the heating chamber. The distance d may be measured perpendicular to a longitudinal axis of the heating chamber. The heating chamber may comprise a heating chamber wall. The heater casing may comprise a heater casing wall. The distance d may be measured radially between the heating chamber wall and the heater casing wall. The distance d may be measured radially between an outer side of the heating chamber wall and an inner side of the heater casing wall. The shielding element may have a radial extension corresponding to the distance d. An outer wall of the shielding element may abut the heater casing wall. An inner wall of the shielding element may abut the heating chamber wall.

[0051] 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.

[0052] The heater casing may be coaxially aligned around the heating chamber. The heating chamber and the heater casing may have matching shapes. The matching shapes may enable a constant radial distance d to be provided between the heater casing and the heating chamber.

[0053] The heater casing wall can match the shape of the heater chamber wall along the longitudinal axis of the heater chamber so that the distance d can be approximately constant. For example, the heater chamber can be a hollow tube, and the heater casing wall can be a cylindrical wall coaxially aligned around the heater chamber. The distance d can be measured radially between the outer diameter of the heater chamber hollow tube and the inner diameter of the heater casing cylindrical wall. For example, the heater chamber can be a hollow truncated cone, and the heater casing wall can be a conical wall coaxially aligned. Those skilled in the art will understand that other types of matching shapes are possible. For example, the matching shape can be curved or wavy, or can include a combination of different shapes along the longitudinal axis of the heater chamber.

[0054] The outer wall of the shielding element may conform to the shape of the wall of the heater casing, and the inner wall of the shielding element may conform to the shape of the wall of the heating chamber.

[0055] The heating chamber and heater casing may have deviating shapes. The shape of the heater casing wall may deviate to some extent from the shape of the heating chamber wall along the longitudinal axis of the heating chamber. The shape of the heater casing wall may deviate from the shape of the heating chamber wall 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-frustoconical hollow cylinder, and the heater casing wall may be a slightly conical hollow cylinder coaxially aligned around the heating chamber. Due to the conical shape of the heater casing wall, the distance d may vary by 1 millimeter or less along the longitudinal axis of the heating chamber.

[0056] The outer diameter of the heater casing, measured perpendicular to the longitudinal axis of the heating chamber, may be between 8 millimeters and 20 millimeters, preferably between 14 millimeters and 18 millimeters, and preferably about 16 millimeters.

[0057] The outer diameter of the heating chamber may be measured 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. Specifically, in one embodiment, the outer diameter of the heating chamber may be about 5.6 millimeters and the outer diameter of the heater casing may be about 17 millimeters, resulting in a ratio of about 3.0. In one embodiment, the outer diameter of the heating chamber may be about 5.6 millimeters and the outer diameter of the heater casing may be about 16.5 millimeters, resulting in a ratio of about 2.95. In one embodiment, the outer diameter of the heating chamber may be about 7.6 millimeters and the outer diameter of the heater casing may be about 16.5 millimeters, resulting in a ratio of about 2.17.

[0058] The airtight space may be hermetically sealed from the outside air, in other words, the interior of the airtight space may not be in fluid communication with the outside air, thereby avoiding heat loss due to gas circulation between the airtight space and the air outside the heater assembly.

[0059] The airtight space may be at ambient pressure. The gas pressure in the airtight space may be between 0.9 bar and 1.1 bar, preferably about 1.0 bar. The airtight space may be filled with the gaseous composition at about ambient pressure at about 20 degrees Celsius. As known to those skilled in the art, temperature-dependent variations in gas pressure in the airtight space may occur. Providing an airtight space at ambient pressure may be less expensive than producing a vacuum airtight space under vacuum. Vacuum-based insulation may be more expensive to manufacture.

[0060] It has been found that a hermetic hollow space having a distance d between 1.5 and 7 millimeters sufficiently reduces heat loss. When providing such a distance d, the air or other gaseous composition enclosed within the hermetic space can be considered still air. Still air, or non-moving air, further reduces air convection within the hermetic space. Heat loss due to air convection within the hermetic space can be reduced.

[0061] 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, using air alone as an insulating material in an airtight hollow space may require a relatively large air gap thickness to provide sufficient insulation.

[0062] The microporous insulating material may have a lower thermal conductivity than air at room temperature. At higher temperatures, the difference between the thermal conductivity of air and the thermal conductivity of the microporous insulating material may become even greater. The thermal conductivity of the microporous insulating material may not increase as rapidly as that of air. The microporous insulating material may substantially maintain its thermal conductivity even at high temperatures. For example, the microporous insulating material may have a thermal conductivity of 0.018 W / m·K at 20°C. At 200°C, the thermal conductivity is 0.022 W / m·K. At a temperature of 400°C, the thermal conductivity increases to 0.028 W / m·K according to ASTM C177. The thermal conductivity of this exemplary microporous insulating material is approximately the same as that of air at room temperature, even above the maximum operating temperature of the aerosol generating device. Lower thermal conductivity provides better insulation.

[0063] An airtight space containing an insulating material 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 a microporous insulating material can have a smaller distance d. A smaller distance d can result in a smaller outer diameter of the aerosol generating device.

[0064] Microporous insulating materials suitable for the present invention may have pore diameters of less than 100 nanometers, preferably less than 70 nanometers, more preferably less than 50 nanometers, more preferably less than 20 nanometers, more preferably less than 2 nanometers.

[0065] The microporous insulating material may be inorganic. The microporous insulating material may be ceramic. The microporous insulating material may include silica (SiO2). The microporous insulating material may include pyrogenic silica. The microporous insulating material may include opacifiers and other components such as fibers. The opacifiers may scatter infrared radiation, thereby reducing its transmission.

[0066] The microporous insulating material of the present disclosure has a porosity of 500 kg / m 3 less than, preferably 400 kg / m 3less than 300 kg / m 3 It may have a nominal density of less than

[0067] The microporous insulating material of the present invention may have a thermal conductivity at 20 degrees Celsius 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 according to ASTM C177. The microporous insulating material may have a thermal conductivity at 280 degrees Celsius 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 according to ASTM C177. The thermal conductivity of the microporous insulating material may increase by up to 40 percent, preferably up to 30 percent, and more preferably up to 20 percent at 280 degrees Celsius compared to the thermal conductivity of the microporous insulating material at 20 degrees Celsius.

[0068] At the operating temperature of the aerosol generating device, an airtight space containing a microporous insulating material may alternatively have a lower thermal conductivity than the same airtight hollow space containing ambient air.

[0069] The airtight space may be completely filled with a microporous insulating material.

[0070] Alternatively, the airtight space may not be completely filled with the microporous insulating material. By not completely filling the airtight space with the microporous insulating material, the weight of the aerosol generating device may be reduced. However, the airtight space may be at least partially filled with the microporous insulating material. The airtight space may also be at least partially filled with a gaseous composition. The gaseous composition may be at ambient pressure. The gaseous composition may be air. The gaseous composition may include one or more of nitrogen, argon, carbon dioxide, oxygen, krypton, sulfur hexafluoride, or mixtures thereof, or other suitable gaseous compositions.

[0071] By additionally providing the gaseous composition in the airtight space, the weight of the aerosol generating device can be reduced. By providing the gaseous composition in the airtight space, the manufacturing costs can be reduced.

[0072] The volume of the airtight space filled with the microporous insulating material may be 30 volume percent, 40 volume percent, 50 volume percent, 60 volume percent, 70 volume percent, 80 volume percent, or 90 volume percent. The ratio of the microporous insulating material to the gaseous composition may depend on the operating temperature of the aerosol-generating device. Aerosol-generating devices with higher operating temperatures may require more microporous insulating material.

[0073] The airtight space may include at least one void. The gaseous composition may be provided within the void.

[0074] The airtight space may include one void. The airtight space may include two voids. The airtight space may include three voids. The shielded microporous insulating material may be radially sandwiched between two voids.

[0075] The gap may have a thickness measured perpendicular to the longitudinal axis of the heating chamber, which may be between 0.5 millimeters and 4 millimeters, preferably between 1 millimeter and 3 millimeters, and more preferably about 2 millimeters.

[0076] One or more voids may be within the microporous insulating material. The voids may be between shielded portions of the microporous insulating material. The one or more voids may extend in a direction parallel to the longitudinal axis of the aerosol generating device. The one or more voids may have a longitudinal extension that is the same as or shorter than the longitudinal extension of the microporous insulating material. The one or more voids may have a circular cross-section. Alternatively, the one or more voids may not extend around the entire circumference of the microporous insulating material. The one or more voids may be completely surrounded by the microporous insulating material. The one or more voids may be in direct contact with the first and second connecting walls, as described in more detail below. The one or more voids may be in direct contact with the heating chamber. The one or more voids may be in direct contact with the heater casing.

[0077] By providing an air gap within the airtight space, the weight of the aerosol generating device can be reduced. By providing an air gap within the airtight space, the manufacturing costs can be reduced.

[0078] The microporous insulating material may be in direct contact with the heating chamber. The microporous insulating material may be surrounded by an air gap. The temperature around the heating chamber may decrease radially with increasing distance from the longitudinal axis of the heating chamber. The microporous insulating material may provide better insulation at higher temperatures than air, for example.

[0079] The heater assembly may include a first microporous insulating material and a second microporous insulating material. At least a portion of the first microporous insulating material may be covered by a first shielding element. At least a portion of the second microporous insulating material may be covered by a second shielding element. The first and second shielded microporous insulating materials may be disposed within an airtight space. The first and second microporous insulating materials may be spaced apart by an air gap in a radial direction perpendicular to the longitudinal axis of the heating chamber.

[0080] The shielding element may be configured to at least partially surround the periphery of the microporous insulating material. The shielding element may be configured to completely surround the periphery of the microporous insulating material.

[0081] The shielding element may be configured to at least partially surround the microporous insulating material. The shielding element may be configured to completely surround the microporous insulating material.

[0082] The shielding element may be configured to abut at least a portion of the microporous insulating material.

[0083] The shielding element may be configured to abut the microporous insulating material. The shielding element may be configured to contact at least a portion of the microporous insulating material. The shielding element may be configured to contact the microporous insulating material. The shielding element may be configured to contact a surface of the microporous insulating material. The shielding element may be configured to contact an outer surface of the microporous insulating material. The shielding element may be configured to cover a surface of the microporous insulating material. The shielding element may be configured to completely cover a surface of the microporous insulating material. The shielding element may be configured to completely cover an outer surface of the microporous insulating material. The shielding element may be configured to encase the microporous insulating material. The shielding element may be configured as a shell of the microporous insulating material.

[0084] The heater assembly may include a heating element, which may be disposed at least partially around the heating chamber.

[0085] The heating chamber may include a heating element. The heating element may be disposed at least partially around the wall of the heating chamber. Preferably, the heating element may be disposed completely coaxially around the periphery of the wall of the heating chamber. The heating element may be disposed along at least a portion of the longitudinal axis of the heating chamber.

[0086] The heating element may comprise one or more conductive tracks on an electrically insulating substrate. The one or more conductive tracks may be resistive heating tracks. The one or more conductive tracks may be configured as an inductively heated susceptor. The electrically insulating substrate may be a flexible substrate.

[0087] The heating element may be flexible and may be wrapped around the heating chamber. The heating element may be disposed between the heating chamber and the heater casing.

[0088] The microporous insulating material may have a longitudinal extension that is the same as or greater than the longitudinal extension of the heating element, thereby ensuring adequate insulation of the heat generated by the heating element.

[0089] The microporous insulating material may extend around the heating element. The shielding element may extend around the heating element.

[0090] In all aspects of the present disclosure, the heating element may comprise an electrically resistive material. Suitable electrically resistive materials include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide), carbon, graphite, metals, alloys, and composites made of ceramic and metallic materials. Such composites may comprise doped or undoped ceramics.

[0091] As noted, in any of the aspects of the present disclosure, the heating element may be part of a heating chamber of a heater assembly for an aerosol-generating device. The heater assembly may include an internal heating element, an external heating element, or both an internal and external heating element, with "internal" and "external" referring to the aerosol-forming substrate. The internal heating element may take any suitable 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 portions or an electrically resistive metal tube. Alternatively, the internal heating element may be one or more heated needles or rods that pass through the center of the aerosol-forming substrate. Other alternatives include a heating wire or filament, such as Ni-Cr (nickel-chromium), platinum, tungsten, or alloy wire or heating plate. Optionally, the internal heating element may be disposed within or on a rigid carrier material. In one such embodiment, the electrically resistive heating element may be formed using a metal with a well-defined 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 a ceramic material, and then sandwiched in another insulating material, such as glass. The heater thus formed may be used to both heat the heating element and monitor its temperature during operation.

[0092] The external heating element may take any suitable 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 foil may be shaped to fit around the substrate-receiving cavity. Alternatively, the external heating element may take the form of a metal grid, a flexible printed circuit board, a molded interconnect device (MID), a ceramic heater, a flexible carbon fiber heater, or may be formed using a coating technique such as plasma deposition on a suitably shaped substrate. The external heating element may also be formed using a metal that has a well-defined relationship between temperature and resistivity. In such an exemplary device, the metal may be formed as a track between two layers of suitable insulating material. An external heating element formed in this manner may be used both to heat the external heating element and to monitor its temperature during operation.

[0093] 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 carrier onto 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.

[0094] In operation, the aerosol-forming substrate may be completely contained within the aerosol-generating device, in which case the user may puff on the mouthpiece of the aerosol-generating device. Alternatively, in operation, the smoking article containing the aerosol-forming substrate may be partially contained within the aerosol-generating device, in which case the user may puff directly on the smoking article.

[0095] The heating element may be configured as an induction heating element. The induction heating element may include an induction coil and a susceptor. Generally, the susceptor is a material capable of generating heat when penetrated by an alternating magnetic field. According to the present invention, the susceptor may be conductive, magnetic, or both conductive and magnetic. The alternating magnetic field generated by one or several induction coils can heat the susceptor, which then transfers heat to the aerosol-forming substrate, resulting in the formation of an aerosol. Heat transfer may be primarily by conduction. Such heat transfer may be best when the susceptor is in intimate thermal contact with the aerosol-forming substrate. When an induction heating element is employed, the induction heating element 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 or forms the sidewall of the cavity.

[0096] The heating chamber may include a central region comprising the heating element. The term central region refers to the longitudinal direction. The heating chamber may further include a proximal region and a distal region. The proximal region and the distal region may be spaced apart from the heating element in the longitudinal direction. During use, the proximal region and the distal region may be cooler than the central region of the heating chamber. The first connecting wall may contact the heating chamber in the proximal region, and the second connecting wall may contact the heating chamber in the distal region. Thus, the first connecting wall and the second connecting wall may contact the heating chamber at the coldest point of the heating chamber during use. Thereby, heat loss from the heating chamber to the connecting walls and the heater casing may be further reduced. Thermal insulation may be further improved.

[0097] The shielding elements may be arranged radially outward of the heating element.

[0098] The shielding element may include a film.

[0099] The shielding element may be configured as a film.The shielding element may consist of a film.

[0100] The microporous insulating material may be configured to be wrapped by a film.

[0101] The film may be made of a material having low thermal conductivity. The film may be made of a polymeric material. The film may be a plastic film. The film may be flexible. The film may be non-porous.

[0102] The film may completely cover the microporous insulating material. The film may completely cover the surface of the microporous insulating material. The film may completely cover the outer surface of the microporous insulating material. The film may encase the microporous insulating material. The microporous insulating material may be completely enclosed within the film. The film may completely surround the microporous insulating material. The film may encase the microporous insulating material. The film may enclose a cavity in the shielding element. The film may be disposed against the microporous insulating material. The film may cover the microporous insulating material. The film may be configured to conform to the shape of the microporous insulating material.

[0103] The film may prevent loose portions of the microporous insulating material from contaminating one or more of the heater casing, the heating element, and the heating chamber.

[0104] The film may be stable at the operating temperature of the heater assembly. The film may be stable at the operating temperature of the aerosol generating device. The film may be configured to withstand temperatures of 200 degrees Celsius to 260 degrees Celsius.

[0105] The film may be selected from one of a polyimide film, a polyetheretherketone film, and a polyurethane film.

[0106] The film may be made from a thermoplastic polyurethane.

[0107] The shielding element may include an adhesive, which may be configured to bond the film to the microporous insulating material.

[0108] The adhesive may be disposed between the microporous insulating material and the film. The adhesive may be disposed on at least a portion of an outer surface of the microporous insulating material. The adhesive may be disposed on at least a portion of the film. The adhesive may be configured to attach the film to the microporous insulating material. The adhesive may cover at least a portion of the film.

[0109] The adhesive may be a silicone adhesive.

[0110] The film and adhesive together may have a thickness of less than 70 micrometers, preferably less than 65 micrometers, and more preferably about 60 micrometers.

[0111] A film and adhesive having a thickness of less than 70 micrometers can both provide sufficient flexibility to the shielding element disposed around the microporous insulation material.A film and adhesive having a thickness of less than 70 micrometers can both provide sufficient flexibility to the shielding element to conform to the shape of the microporous insulation material.

[0112] The shielding element may be configured as a coating on the microporous insulating material. The coating may be paint.

[0113] The shielding element may comprise a coating. The coating may be disposed on an outer surface of the microporous insulation material. The coating may be disposed on at least a portion of the outer surface of the microporous insulation material. The coating may be disposed on the outer surface of the microporous insulation material. The coating may completely cover the microporous insulation material. The coating may completely cover the surface of the microporous insulation material. The coating may completely cover the outer surface of the microporous insulation material. The coating may completely surround the microporous insulation material. The coating may encase the microporous insulation material. The coating may be applied to the outer surface of the microporous insulation material. The coating may adhere to the outer surface of the microporous insulation material.

[0114] The coating may prevent the microporous insulating material from contaminating one or more of the heater casing, the heating element, and the heating chamber. The coating may prevent the microporous insulating material from contacting one or more of the heater casing, the heating element, and the heating chamber.

[0115] The coating may be non-porous. The coating may be formed of a thermally conductive material. The coating may include an elastomer.

[0116] The coating may be an anti-fouling coating. The coating may be configured to be anti-fouling. The coating may be a non-stick coating. The coating may be stable at the operating temperature of the heater assembly. The coating may be stable at the operating temperature of the aerosol generating device. The coating may be configured to withstand temperatures between 200°C and 260°C.

[0117] The coating may be a silicone coating.

[0118] The microporous insulating material may include silicon dioxide.

[0119] One or more of the heating chamber, heater casing, microporous insulating material, and heating element may be configured to be hollow tubular.

[0120] The heater assembly may include a first connecting wall connecting the heating chamber and the heater casing. The heater assembly may include 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.

[0121] The airtight space may be defined by the walls of the heating chamber and the heater casing and the first and second connecting walls. The first and second connecting walls may provide for easy assembly of the airtight space. The first and second connecting walls may provide for 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 may be ensured. By providing the first and second connecting walls, accurate placement of the shielded microporous insulating material may be ensured. The first and second connecting walls may contact the shielded microporous insulating material, thereby preventing heat loss due to air convection over the proximal and distal ends of the shielded microporous insulating material.

[0122] The first and second connecting walls may each extend between a wall of the heating chamber and a wall of the heater casing. The first and second connecting walls may sealingly connect the heater casing to an 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.

[0123] The first connecting wall may be configured to abut the first intermediate wall, and the second connecting wall may be configured to abut the second intermediate wall.

[0124] The shielding element may be in direct contact with the heating chamber. The shielding element may be in direct contact with the heater casing. The shielding element may be in direct contact with the first and second connecting walls. The shielding element may be in direct contact with the heating chamber and the heater casing. The shielding element may be in direct contact with the heating chamber, the heater casing, and the first and second connecting walls. The shielded microporous insulating material may be attached between the first and second connecting walls. The shielded microporous insulating material may be disposed across the distance between the first and second connecting walls. The shielded microporous insulating material may be attached between the first and second connecting walls, while not in contact with one or both of the heater casing and the heating chamber.

[0125] The shielded microporous insulating material may have elongated extensions. The shielded microporous insulating material may extend parallel to the longitudinal axis of the heat chamber. The shielded microporous insulating material may be a hollow tube extending around the heat chamber.

[0126] The shielded microporous insulating material may have a thickness measured perpendicular to the longitudinal axis of the heating chamber. The shielded microporous insulating material may have a thickness equal to the distance d. The thickness of the shielded microporous insulating material may be 1 millimeter to 7 millimeters, preferably 2 millimeters to 6 millimeters, and more preferably 3 millimeters to 5 millimeters.

[0127] The microporous insulating material may be formed from one single element. Alternatively, the microporous insulating material may be formed from at least two insulating elements. The heater assembly may include two or more shielding elements as described herein. One or more of the insulating elements may be covered by a shielding element as described herein. Each of the insulating elements may be at least partially covered by a separate shielding element as described herein. Each of the insulating elements may be covered by a shielding element as described herein. A single shielding element as described herein may cover at least two insulating elements. The microporous insulating material may be formed from two insulating elements. Each of the two insulating elements may be covered by a shielding element as described herein. Two insulating elements may be covered by a single shielding element as described herein.

[0128] The microporous insulating material may be formed from at least a first insulating element including at least a first connecting element and a second insulating element including at least a second connecting element. The first microporous insulating element may be at least partially covered by a shielding element described herein. The second microporous insulating element may be at least partially covered by a shielding element described herein. The shielding element described herein may surround the first microporous insulating element. The shielding element described herein may surround the second microporous insulating element. The shielding element described herein may surround both the first microporous insulating element and the second microporous insulating element. The first and second connecting elements may be configured as mating connecting elements. When connected, the mating connecting elements may enable connection of the first and second microporous insulating elements. The connected first and second connecting elements may result in the overall insulating material forming a hollow tube. The hollow tube may have an inner diameter corresponding to the outer diameter of the heating chamber. By providing the microporous insulating material from two insulating elements, simple assembly of the microporous insulating material can be provided around the heating chamber. By forming the microporous insulating material from two insulating elements, a perfect form fit between the shielded microporous insulating material and the heating chamber can be provided. By providing a perfect form fit between the shielded microporous insulating material and the heating chamber, better insulation can be ensured.

[0129] The first and second connection elements may be configured as male and female connection elements, form-fit connection elements, snap-fit ​​connection elements, bayonet-type connection elements, or combinations thereof, or other commonly used connection elements known to those skilled in the art. The first connection element may include a male connection element and the second connection element may include a female connection element. The first and second connection elements may include form-fit connection elements. The first and second connection elements may include snap-fit ​​connection elements. The first and second connection elements may include bayonet-type connection elements.

[0130] The microporous insulating material may be configured as a two-piece assembly. The two-piece assembly may include a first microporous insulating element and a second microporous insulating element. The first microporous insulating element and the second microporous insulating element may be in the form of, for example, a hollow semi-cylindrical element. The hollow semi-cylindrical element may include mating 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. Each of the first and second microporous insulating elements may be at least partially covered by a shielding element as described herein. Proximity or direct contact of the microporous insulating material with the heating chamber may improve insulation of the heating chamber.

[0131] The heating chamber may include a temperature sensor. The temperature sensor may be on the top of the heating chamber. The shielded microporous insulating material may have a shape that matches the temperature sensor. The shielded microporous insulating material may have a cavity facing the temperature sensor. The shielded microporous insulating material may be completely enclosed around the heating chamber. The temperature sensor may be surrounded by the shielded microporous insulating material. The temperature sensor may be sandwiched between the heating chamber and the shielded microporous insulating material.

[0132] The walls of the heating chamber may be made of stainless steel, which may advantageously enhance the effect that the proximal and distal regions may be cooler than the central region of the heating chamber during use.

[0133] The heater casing wall thickness may be less than about 2 millimeters. The heater casing wall thickness may be less than 1.2 millimeters, preferably about 0.8 millimeters. One or both of the first connecting wall and the second connecting wall may have a thickness less than 1.2 millimeters, preferably about 0.8 millimeters. With such thin walls, the thermal mass of the heater casing may be minimized, which may further reduce heat loss from the heating chamber.

[0134] One or more of the heater casing wall and the first and second connecting walls may be made of a low thermal conductivity material. This may further reduce heat loss from the heating chamber. The heater casing wall may include or be made of a plastic material. The first and second connecting walls may include or be made of a plastic material. The plastic material may include one or both of polyaryletherketone (PAEK), polyetheretherketone (PEEK), and polyphenylenesulfone (PPSU). Preferably, the plastic material includes polyphenylenesulfone (PPSU).

[0135] The inside of the heater casing wall may include a metal coating. The inside of one or both of the first connecting wall and the second connecting wall may include a metal coating. The metal coating may reduce the emissivity of the inside of the wall. For example, the emissivity of a PEEK wall may be reduced from about 0.95 to about 0.4. The metal coating may reflect thermal radiation radiated from the heating chamber. The metal coating may provide additional insulation of the heating chamber from the outside of the heater casing. The metal coating may be a low-emissivity metal coating. The metal coating may include one or more of aluminum, gold, and silver.

[0136] The airtight space may be at least partially filled with the microporous insulating material. The airtight space may be only partially filled with the microporous insulating material.

[0137] The airtight space may be only partially filled with the blocked microporous insulating material.The airtight space may be only partially filled with the blocked microporous insulating material.

[0138] The airtight space may include at least one gap.

[0139] The microporous insulating material may be radially sandwiched between the two voids.

[0140] The shielded microporous insulating material may be radially sandwiched between two voids.

[0141] The microporous insulating material may have elongated extensions. The microporous insulating material may extend parallel to the longitudinal axis of the heating chamber.

[0142] The shielded microporous insulating material may have elongated extensions. The shielded microporous insulating material may extend parallel to the longitudinal axis of the heating chamber.

[0143] Preferably, the shielding element is configured as a film, the film being configured to completely surround the microporous insulating material.

[0144] Preferably, the shielding element is configured as a covering, the covering being configured to completely surround the microporous insulating material.

[0145] The present invention further relates to an aerosol generating device comprising the heater assembly described above.

[0146] The aerosol generating device may include a power source configured to power the heating element. The power supply may include a power source. The power source may be a battery. The power source may be 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 operation of the heater assembly.

[0147] The power supply may comprise control electronics. The control electronics may comprise a microcontroller. The microcontroller may be a programmable microcontroller. The electrical circuit may comprise 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 activation of the system, or may be supplied intermittently (e.g., between puffs). Power may be supplied to the heater assembly in the form of current pulses.

[0148] The present invention further relates to an aerosol generation system comprising an aerosol generation device as described herein and an aerosol-forming substrate that may be configured to be at least partially received within a heating chamber.

[0149] The present invention further relates to an aerosol generation system comprising an aerosol generation device as described herein and an aerosol-forming substrate configured to be at least partially received within the heating chamber.

[0150] The term "aerosol-forming substrate" as used herein may refer to a substrate capable of releasing a volatile compound capable of forming an aerosol. The volatile compound may be released by heating or burning the aerosol-forming substrate. As an alternative to heating or burning, in some cases the volatile compound may be released by a chemical reaction or by mechanical stimulation such as ultrasound. The aerosol-forming substrate may be solid or liquid, or may include both solid and liquid components. The aerosol-forming substrate may be part of an aerosol-generating article.

[0151] The aerosol-forming substrate may be a solid aerosol-forming substrate. The aerosol-forming substrate may include both solid and liquid components. The aerosol-forming substrate may include a tobacco-containing material containing volatile tobacco flavor compounds that are released from the substrate upon heating. The aerosol-forming substrate may include a non-tobacco material. The aerosol-forming substrate may include an aerosol former that facilitates the formation of a high-density and stable aerosol. Examples of suitable aerosol formers are glycerin and propylene glycol.

[0152] As used herein, the term "aerosol-generating article" may refer to an article that includes an aerosol-forming substrate capable of emitting a volatile compound that can form an aerosol. The aerosol-generating article may be disposable.

[0153] As used herein, the term "aerosol-generating device" may refer to a device that interacts with an aerosol-forming substrate to generate an aerosol. The aerosol-generating device may interact with one or both of an aerosol-generating article including the aerosol-forming substrate and a cartridge including the aerosol-forming substrate. In some examples, the aerosol-generating device may heat the aerosol-forming substrate to facilitate release of the volatile compound from the substrate. An electrically operated aerosol-generating device may include an atomizer, such as an electric heater, to heat the aerosol-forming substrate to form an aerosol.

[0154] As used herein, the term "aerosol-generating system" can refer to the combination of an aerosol-generating device with an aerosol-forming substrate. Where the aerosol-forming substrate forms part of an aerosol-generating article, the aerosol-generating system refers to the combination of the aerosol-generating device with the aerosol-generating article. In an aerosol-generating system, the aerosol-forming substrate and the aerosol-generating device work together to generate the aerosol.

[0155] The present invention provides a method for manufacturing the heater assembly described above, comprising the steps of: a) providing a shielding element configured as a film; b) applying an adhesive to at least a portion of the film; c) bonding the microporous insulating material to at least a portion of the film via an adhesive; d) folding at least a portion of the film over at least a portion of the microporous insulating material to at least partially enclose the microporous insulating material; e) disposing the at least partially enclosed microporous insulating material within the airtight space.

[0156] The present invention provides a method for manufacturing the heater assembly described above, comprising the steps of: a) providing a shielding element configured as a film; b) applying an adhesive to at least a portion of the film; c) bonding the microporous insulating material to at least a portion of the film via an adhesive; d) folding at least a portion of the film over at least a portion of the microporous insulating material to at least partially enclose the microporous insulating material; e) disposing the at least partially enclosed microporous insulating material within the airtight space.

[0157] The film may include a protective layer. An adhesive may be applied to the film. The protective layer may be removably attached to the adhesive applied to the film. The protective layer may be removed prior to bonding the microporous insulating material to at least a portion of the film via the adhesive. The protective layer may reduce the risk of contamination of the adhesive prior to application to the film. Use of the protective layer may improve the fit between the microporous insulating material and the adhesive.

[0158] In step a), the provided film can be a cruciform film having at least four arms connected by a central portion. In step b), adhesive can be applied to at least a portion of the central portion of the film. In step c), a microporous insulating material can be bonded to at least a portion of the central portion of the cruciform film via the adhesive. In step d), at least three arms of the cruciform film can be folded over at least a portion of the microporous insulating material to at least partially enclose the microporous insulating material.

[0159] The film may be cross-shaped. The film may have a symmetrical cross shape. The film may have a central portion. The central portion may be rectangular. The film may have four arms. The four arms may be disposed around the central portion of the film. One or more of the four arms may be rectangular. Each arm may be disposed along an edge of the central portion of the film. The arms at opposite edges of the central portion may be configured to be identical. The arms at opposite edges of the central portion may be configured to be different. Two arms disposed at a first pair of opposite edges of the central portion may be configured to be identical. Two arms disposed at a second pair of opposite edges of the central portion may be configured differently. The arm disposed at a first edge of the central portion may be elongated compared to the arm disposed at a second edge of the central portion opposite the first edge. The elongated arms may be wrapped around the microporous insulation material to secure the microporous insulation material to the heating chamber. The four arms and the central portion may form a continuous film.

[0160] In step a), the provided cruciform film may have a first arm that is elongated relative to the arm disposed opposite the first arm. In step d), the second arm, the third arm, and the fourth arm may be folded over at least a portion of the central portion of the film to at least partially surround the microporous insulating material. In step e), the at least partially surrounded microporous insulating material may be wrapped around a heating chamber and fitted to the heating chamber by wrapping the first arm at least partially around the microporous insulating material.

[0161] In step a), the provided cross-shaped film can have opposing arms configured to be identical. In step d), all four arms can be folded toward a central portion of the film to completely enclose the microporous insulation material. In step e), the enclosed microporous insulation material can be disposed against a heater casing. [Example]

[0162] The present invention is defined in the claims. However, the following provides 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 any other example, embodiment, or aspect described herein.

[0163] Example 1: 1. A heater assembly for an aerosol generating device, comprising: a heating chamber for heating the aerosol-forming substrate; a heater casing disposed around the heating chamber and radially spaced from the heating chamber, the heater casing including an airtight space, the airtight space including a microporous insulating material; The heater assembly, wherein the airtight space comprises a shielding element, the shielding element configured to cover at least a portion of the microporous insulating material. Example 2: 2. The heater assembly of example 1, wherein the shielding element is configured to at least partially, and preferably completely, surround the microporous insulating material. Example 3: 3. The heater assembly of example 2, wherein the shielding element is configured to at least partially, and preferably completely, surround the microporous insulating material. Example 4: 4. The heater assembly of any one of Examples 1-3, wherein the shielding element is configured to abut at least a portion of the microporous insulating material. Example 5: 5. The heater assembly of any of Examples 1-4, wherein the heater assembly comprises a heating element, the heating element preferably being disposed at least partially around the heating chamber. Example 6: 6. The heater assembly of example 5, wherein the shielding element is disposed radially outward of the heating element. Example 7: The heater assembly of any one of Examples 1 to 6, wherein one or more of the heating chamber, heater casing, microporous insulating material, and heating element of Example 5 or Example 6 are configured to be hollow tubular. Example 8: The heater assembly of any one of Examples 1 to 7, further comprising 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, wherein the airtight space is defined between the heating chamber, the heater casing, and the first and second connecting walls. Example 9: 9. The heater assembly of any of Examples 1-8, wherein the airtight space is at least partially filled with the microporous insulating material, preferably the airtight space is only partially filled with the microporous insulating material. Example 10: 10. The heater assembly of any one of Examples 1 to 9, wherein the airtight space includes at least one void. Example 11: 11. The heater assembly of example example 10, wherein the microporous insulating material is radially sandwiched between two voids. Example 12: 12. The heater assembly of any of Examples 1-11, wherein the microporous insulating material has elongated extensions, the microporous insulating material preferably extending parallel to the longitudinal axis of the heating chamber. Example 13: The heater assembly of any of Examples 1-12, wherein the shielding element comprises a film. Example 14: 14. The heater assembly of example embodiment 13, wherein the microporous insulating material is configured to be wrapped by a film. Example 15: The heater assembly of example 13 or example 14, wherein the film is selected from one of a polyimide film, a polyetheretherketone film, and a polyurethane film. Example 16: 16. The heater assembly of any of Examples 13-15, wherein the shielding element comprises an adhesive, the adhesive configured to bond the film to the microporous insulating material. Example 17: The heater assembly of example 16, wherein the adhesive is a silicone adhesive. Example 18: The heater assembly of Example 16 or Example 17, wherein the film and adhesive together have a thickness of less than 70 micrometers, preferably less than 65 micrometers, and more preferably about 60 micrometers. Example 19: 13. The heater assembly of any of Examples 1-12, wherein the shielding element is configured as a coating on the microporous insulating material, preferably the coating is paint. Example 20: The heater assembly of example 19, wherein the coating is a silicone coating. Example 21: 21. The heater assembly of any of Examples 1-20, wherein the microporous insulating material comprises silicon dioxide. Example 22: An aerosol generating device comprising the heater assembly according to any one of Examples 1 to 21. Example 23: An aerosol-generating system comprising the aerosol-generating device of Example 22 and an aerosol-forming substrate configured to be at least partially received within a heating chamber. Example 24: A method for manufacturing the heater assembly of any of Examples 13-18, comprising: a) providing a shielding element configured as a film; b) applying an adhesive to at least a portion of the film; c) bonding the microporous insulating material to at least a portion of the film via an adhesive; d) folding at least a portion of the film over at least a portion of the microporous insulating material to at least partially enclose the microporous insulating material; e) disposing an at least partially enclosed microporous insulating material within the airtight space. Example 25: In step a), the film provided is a cross-shaped film having at least four arms connected by a central portion; In step b), adhesive is applied to at least a portion of the central portion of the film; In step c), the microporous insulating material is bonded to at least a portion of the central portion of the cross-shaped film via an adhesive; 25. The method of example 24, wherein in step d), at least three arms of the cross-shaped film are folded over at least a portion of the microporous insulating material to at least partially surround the microporous insulating material. Example 26: In step a), the provided cross-shaped film has a first arm that is elongated compared to an arm disposed opposite the first arm, In step d), the second arm, the third arm, and the fourth arm are folded over at least a portion of the central portion of the film to at least partially enclose the microporous insulating material; 26. The method of example 25, wherein in step e), the at least partially enclosed microporous insulating material is wrapped around the heating chamber and engaged with the heating chamber by wrapping the first arm at least partially around the microporous insulating material. Example 27: In step a), a cruciform film is provided having opposing arms configured to be identical, In step d), all four arms are folded toward the central portion of the film to completely enclose the microporous insulating material; 26. The method of example 25, wherein in step e), the enclosed microporous insulating material is preferably disposed against the heater casing.

[0164] The following provides 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 any other example, embodiment, or aspect described herein.

[0165] Features described with respect to one embodiment may be equally applied to other embodiments of the invention.

Claims

1. 1. A heater assembly for an aerosol generating device, comprising: a heating chamber for heating the aerosol-forming substrate; a heater casing disposed around the heating chamber and radially spaced from the heating chamber, the heater casing including an airtight space, the airtight space including a microporous insulating material; The heater assembly, wherein the airtight space comprises a shielding element, the shielding element configured to cover at least a portion of the microporous insulating material.

2. The heater assembly of claim 1 , wherein the shielding element is configured to at least partially, preferably completely, surround the microporous insulating material.

3. The heater assembly of any one of claims 1 to 2, wherein the shielding element is configured to abut at least a portion of the microporous insulating material.

4. A heater assembly according to any preceding claim, wherein the heater assembly comprises a heating element, the heating element preferably being disposed at least partially around the heating chamber.

5. The heater assembly of claim 4 , wherein the shielding element is disposed radially outward of the heating element.

6. A heater assembly as described in any one of claims 1 to 5, wherein one or more of the heating chamber, the heater casing, the microporous insulating material, and the heating element as described in claim 4 or claim 5 are configured to be hollow tubular.

7. The heater assembly of any preceding claim, wherein the shielding element comprises a film.

8. The heater assembly of claim 7 , wherein the microporous insulating material is configured to be wrapped by the film.

9. A heater assembly according to any preceding claim, wherein the shielding element is configured as a coating on the microporous insulating material, preferably the coating being paint.

10. An aerosol generating device comprising the heater assembly according to any one of claims 1 to 9.

11. 11. An aerosol generation system comprising the aerosol generating device of claim 10 and an aerosol-forming substrate configured to be at least partially received within the heating chamber.

12. 9. A method for manufacturing a heater assembly according to claim 7 or claim 8, comprising the steps of: a) providing a shielding element configured as a film; b) applying an adhesive to at least a portion of said film; c) bonding the microporous insulating material to at least a portion of the film via the adhesive; d) folding at least a portion of the film over at least a portion of the microporous insulating material to at least partially enclose the microporous insulating material; e) disposing the at least partially enclosed microporous insulating material within the airtight space.

13. In step a), the provided film is a cruciform film having at least four arms connected by a central portion; In step b), the adhesive is applied to at least a portion of the central portion of the film; In step c), the microporous insulating material is bonded to at least a portion of the central portion of the cruciform film via the adhesive; 13. The method of claim 12, wherein in step d), at least three arms of the cruciform film are folded over at least a portion of the microporous insulating material to at least partially surround the microporous insulating material.

14. In step a), the provided cruciform film has a first arm that is elongated compared to the arm disposed on the opposite side of the first arm; In step d), second, third, and fourth arms are folded over at least a portion of the central portion of the film to at least partially enclose the microporous insulating material; 14. The method of claim 13, wherein in step e), the at least partially enclosed microporous insulating material is wrapped around the heating chamber and fitted to the heating chamber by wrapping the first arm at least partially around the microporous insulating material.

15. In step a), the provided cruciform film has opposing arms configured to be identical; In step d), all four arms are folded toward the central portion of the film to completely enclose the microporous insulating material; 14. The method of claim 13, wherein in step e), the surrounded microporous insulating material is preferably disposed against the heater casing.

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