Heating unit for an aerosol generating device

Abstract

A heating unit (100) for an aerosol-generating device is disclosed. The heating unit includes heaters (102, 103) defining a heating chamber (104) capable of receiving an aerosol-generating substrate (101). The heating unit also includes a frame (106) configured to at least partially surround the heater, the frame being in thermal contact with the heater so as to be sealed to the heater.

Description

[Technical Field]

[0001] The present invention relates to a heating unit for an aerosol generating device. [Background technology]

[0002] A need exists for an aerosol-generating device that heats, but does not combust, a solid or semi-solid aerosol-forming substrate, including tobacco. The aerosol-generating substrate is typically heated by a heater in a heating chamber, and the generated aerosol is inhaled by the user through a mouthpiece.

[0003] A problem that exists with these devices is that the aerosol generated can leak from the heating chamber into areas of the device other than the mouthpiece. This type of leakage is important to prevent, especially since it can cause damage to other components of the device.

[0004] Furthermore, commercially available sealants suitable for food-grade use are typically ineffective at preventing this aerosol leakage. This is due to the fact that these particular sealants are susceptible to damage from repeated heating and cooling over extended use of the aerosol generating device. Sealant that are effective at preventing this aerosol leakage are typically not suitable for food-grade use. Summary of the Invention [Problem to be solved by the invention]

[0005] It is an object of the present invention to provide a heating unit for an aerosol generating device that can prevent or reduce problems associated with unwanted aerosol leakage. [Means for solving the problem]

[0006] Described herein is a heating unit for an aerosol generating device comprising a heater defining a heating chamber capable of receiving an aerosol-generating substrate, and a frame configured to at least partially surround the heater, the frame being in thermal contact with the heater such that the frame is sealed to the heater.

[0007] In one aspect of the present invention, there is provided a heating unit for an aerosol generating device, comprising: a heater defining a heating chamber capable of receiving an aerosol-generating substrate, the heater being configured to be in direct contact with the aerosol-generating substrate when the aerosol-generating substrate is received in the heating chamber; and a frame configured to only partially surround the heater, the frame being in thermally sealed contact with the heater such that the frame is sealed to the heater.

[0008] In this way, the frame can be tightly bonded to the heater, thereby forming a single component and thus preventing unwanted aerosol leakage from areas of the heating chamber not surrounded by the frame. The frame typically includes an opening fluidly connected to a mouthpiece of the device through which a user can inhale the generated aerosol. To form the heating unit, the heater can be placed in a mold with the frame material injected into the mold. Alternatively, the frame can be attached to the heater and then heated to seal the frame to the heater, forming a bonded heating unit. In a further alternative, the frame can be crimped to the heater after being heated to achieve a seal.

[0009] Preferably, the heater includes one or more mating features configured to engage with the frame. In this way, the strength of the seal between the heater and the frame can be improved as the heater and frame are more tightly bonded together.

[0010] Preferably, at least one of the one or more bonding features comprises one or more holes provided through the heater. Preferably, the frame comprises a securing portion extending through the one or more holes, thereby securing the frame to the heater. In this manner, the frame penetrates and penetrates the heater, thus further securing the seal between the frame and the heater.

[0011] Preferably, the fixing portion comprises a lug. In this way, the frame is riveted to the heater, thereby improving the bond between the frame and the heater. The strength and durability of the heating unit can also be improved.

[0012] Preferably, the frame comprises a thermoplastic material. For example, the frame may comprise PEEK. In this manner, the frame can be thermally sealed to the heater and then cooled to form a seal. The frame should preferably comprise a material that has a melting point temperature higher than the operating temperature of the heater of the heating unit.

[0013] Described herein is a method of forming a heating unit for an aerosol generating device, comprising heating a frame material, sealing the frame material to a heater to at least partially surround the heater, and cooling the frame material to form a seal with the heater.

[0014] In another aspect of the invention, there is provided a method of forming a heating unit for an aerosol generating device, comprising heating a frame material, sealing the frame material to a heater to only partially surround the heater, the heater defining a heating chamber capable of receiving an aerosol-generating substrate, the heater being configured to be in direct contact with the aerosol-generating substrate when the aerosol-generating substrate is received in the heating chamber, and cooling the frame material to form a seal with the heater.

[0015] Preferably, the method further includes adhering a frame material to at least one of the one or more bonding features of the heater. The frame material may be adhered to at least one of the one or more bonding features of the heater by injecting heated frame material into a mold in which the heater is provided. The heated frame material then surrounds the heater and penetrates into the one or more bonding features as more heated frame material is injected into the mold.

[0016] Preferably, the method further includes extending a fixed portion of the frame material through one or more holes in the heater before the heating step. In this way, the frame material may penetrate and penetrate the heater, thus further tightening the seal between the frame material and the heater when the heating unit is formed. The frame material may already be manufactured and shaped to fit the heater. In this example, the frame material and the heater are then interlocked so that the fixed portion of the frame material extends through one or more holes in the heater. Alternatively, this step may be achieved by injecting the heated frame material through one or more holes in the heater.

[0017] Preferably, sealing the frame material to the heater includes sealing the fixed portion of the frame material to the heater. In this manner, the frame material is riveted to the heater, thereby improving the bond between the frame material and the heater. The strength and durability of the formed heating unit can also be improved. When the fixed portion of the frame material extends through one or more holes in the heater, the fixed portion of the frame material can be sealed to the heater. Sealing the fixed portion to the frame can be achieved by heating the fixed portion and applying pressure to the fixed portion.

[0018] In another configuration, the frame material may be in the form of pellets prior to the heating step. This is an example of overmolding, where the frame material is positioned around the heater and then heated to a fluid state so that it thermally conforms to the shape of the heater. The frame material can then be cooled and solidify around the heater, forming a seal that prevents or at least reduces unwanted steam leakage.

[0019] Embodiments of the present invention will now be described, by way of example, with reference to the drawings, in which: [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a perspective view of an aerosol generating device including a heating unit in an embodiment of the present invention. [Figure 2] FIG. 1 is a perspective view of a heating unit for an aerosol generating device in accordance with an embodiment of the present invention. [Figure 3] 1 is a schematic cross-sectional view of a heating unit for an aerosol generating device in accordance with an embodiment of the present invention. [Figure 4] FIG. 10 is a schematic cross-sectional view of a heating unit for an aerosol generating device in another embodiment of the present invention. [Figure 5] FIG. 10 is a schematic cross-sectional view of a heating unit for an aerosol generating device in another embodiment of the present invention. [Figure 6] FIG. 10 is a schematic cross-sectional view of a heating unit for an aerosol generating device in another embodiment of the present invention. [Figure 7] FIG. 1 is a flow diagram of a method for forming a heating unit for an aerosol generating device in accordance with an embodiment of the present invention. [Figure 8] 1 is a schematic cross-sectional view of a method for forming lugs on a heating unit for an aerosol generating device in an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] 1 is a perspective view of an aerosol-generating device 1 including a heating unit according to one embodiment of the present invention. The heating unit is provided internally within the aerosol-generating device 1. An aerosol-generating substrate 101 is provided within the aerosol-generating device 1 and within the heating unit. The aerosol-generating device 1 includes a mouthpiece 2 that allows a user to inhale the aerosol that is generated when the aerosol-generating substrate 101 is heated by the heating unit.

[0022] The heating unit is connected to a power source, such as a battery, provided within the aerosol generating device 1 .

[0023] The aerosol-generating substrate 101 extends from within the heating unit into the mouthpiece 2. The mouthpiece 2 includes an aperture 3 that is fluidly connected to the heating unit. The mouthpiece 2 is shaped to allow a user to place their lips around the exterior and inhale the aerosol through the aperture 3.

[0024] Figure 2 is a schematic diagram of a heating unit 100 for an aerosol-generating device according to one embodiment of the present invention. In the example of Figure 2, an aerosol-generating substrate 101 is partially disposed within and partially extends from the heating unit 100. The aerosol-generating substrate 101 is removable from the heating unit 100 so that it can be replaced when it is depleted. Figure 3 is a schematic cross-sectional view of the heating unit 100 according to one embodiment of the present invention. In the embodiment of Figure 3, the aerosol-generating substrate is not disposed within the heating unit 100.

[0025] The heating unit 100 has a generally elongated rectangular shape. The heating unit 100 includes a first heating element 102 and a second heating element 103, which may be collectively referred to as heaters. The first heating element 102 and the second heating element 103 are separated from each other and define a heating chamber 104 between them, into which an aerosol-generating substrate 101 can be inserted. The heating unit 100 also includes a frame 106 that supports and partially surrounds the first heating element 102 and the second heating element 103, and thus also partially surrounds the heating chamber 104. The frame is in thermal contact with the first heating element 102 and the second heating element 103. The frame 106 includes an opening 107 that defines the opening of the heating chamber 104. The frame 106 surrounds the first heating element 102 and the second heating element 103 around all surfaces except for the opening 107.

[0026] The heating unit 100 is electrically and mechanically connected to the body of the aerosol generation device. Thus, the first heating element 102 and the second heating element 103 may be electrically connected to a power source, such as a battery, within the body of the aerosol generation device. The frame 106 may be molded around such electrical connections so that power can be supplied to the first heating element 102 and the second heating element 103.

[0027] The first heating element 102 and the second heating element 103 are spaced apart to allow the aerosol-generating substrate to be snugly received within the heating chamber 104 .

[0028] The first heating element 102 and the second heating element 103 are configured on the produce for heating during operation of the aerosol-generating device, in order to heat the aerosol-generating substrate 101 when received within the heating chamber 104. The first heating element 102 and the second heating element 103 typically directly contact opposite major surfaces of the aerosol-generating substrate 101 when such substrate 101 is received within the heating chamber 104.

[0029] In this embodiment, the first heating element 102 and the second heating element 103 are substantially planar ceramic heating elements. Other types of heaters, such as trace heaters, may also be used.

[0030] The frame 106 is sealed to the first heating element 102 and the second heating element 103 to prevent leakage of aerosol from the heating chamber 104 except through the opening 107. This is achieved by providing the frame material 106 around five of the six surfaces that form the substantially rectangular parallelepiped that forms the heating unit 100. The frame material is absent only on the front surface where the opening 107 is located.

[0031] In this example, the frame 106 comprises a thermoplastic material (e.g., PEEK) that is heated to become malleable, allowing the frame 106 to be tightly fitted to the first and second heating elements 102, 103. This forms a seal between the frame 106 and the first and second heating elements 102, 103 upon cooling of the thermoplastic material.

[0032] 4 is a schematic cross-sectional view of a heating unit 100 for an aerosol generating device in another embodiment of the present invention. In this configuration, the first heating element 102 and the second heating element 103 each include a channel 108 in their respective major planar surfaces that contact the frame 106. Additionally, a channel 109 is provided on the side of the first heater 102 and the second heater 103. The channels 108 and 109 collectively form a joining feature.

[0033] The channels 108 of the first heating element 102 and the second heating element 103 have a triangular cross-section, and the channels 109 have a rectangular cross-section (although one skilled in the art will understand that these are merely examples). The channels 108, 109 are provided along the length of each of the first heating element 102 and the second heating element 103. When the frame 106 is thermally sealed to the first heating element 102 and the second heating element 103, the softened or malleable frame tends to flow into the channels 108, 109, thereby sealing the frame 106 to the first heating element 102 and the second heating element 103 and improving the strength of the bond.

[0034] 5 is a schematic cross-sectional view of a heating unit for an aerosol generating device according to another embodiment of the present invention. In this configuration, holes 110 are provided through the first heating element 102 and the second heating element 103. The holes 110 collectively form joining features for the first heating element 102 and the second heating element 103. The frame 106 includes protrusions 111 extending through the holes 110. In this example, the protrusions 111 are fastening parts. The holes 110 and the protrusions 111 interlock with each other to seal the frame 106 to the first heating element 102 and the second heating element 103. The protrusions 111 of the frame 106 are also thermally sealed to the holes 110 of the first heating element 102 and the second heating element 103.

[0035] 5, protrusions 111 from frame 106 are provided at least partially within heating chamber 104. In other words, the length of protrusions 111 is slightly longer than the length of the corresponding holes 110. In various embodiments, protrusions 111 may instead be provided entirely within holes 110.

[0036] 6 is a schematic cross-sectional view of a heating unit 100 for an aerosol generating device according to another embodiment of the present invention. In this configuration, the protrusions 111 of the frame 106 are provided with lugs 112.

[0037] In this embodiment of the invention, the protrusions 111 of the frame 106 extend at least partially into the heating chamber 104. More specifically, the end of each protrusion 111 of the frame 106 extends from the hole 110 into the heating chamber 104. The end of the protrusion 111 that extends into the heating chamber 104 forms a lug 112. The lug 112 has a radial cross-section that is larger than the radial cross-section of the corresponding hole 110.

[0038] 7 is a flow diagram of a method 700 for forming a heating unit 100 for an aerosol generating device according to one embodiment of the present invention. The method includes step 702 of heating a frame material, step 704 of sealing the frame material to the heater to at least partially surround the heater, step 706 of sealing the frame material to at least one of the one or more bonding features of the heater, and step 708 of cooling the frame material to form a seal with the heater.

[0039] In step 702, the frame material is heated. The frame material is heated to a molten state or to become malleable. The frame material may be heated by heating in an oven, furnace, or the like. The frame material must be heated to a temperature suitable for injection molding so that the heated frame material will surround the heater in the subsequent sealing step. In an embodiment of the invention in which the frame material comprises PEEK, the frame material must be heated to a temperature above the glass transition temperature of PEEK, which is approximately 143 degrees Celsius.

[0040] In step 704, the frame material is sealed to the heater to at least partially surround the heater. This is accomplished by placing the heater in a mold and injecting heated or molten frame material into the mold. This step may be performed, for example, by an overmolding process. If the method includes overmolding, the frame material may first be provided as a plurality of pellets that can be melted so that the frame material flows around the heater.

[0041] In step 706, the frame material is bonded to at least one of the heater's one or more bonding features. This can also be accomplished by injecting heated molten frame material into a mold in which the heater is located. This step can also be performed by an overmolding process. The heater's bonding features can be formed in a further forming step prior to the bonding step described herein.

[0042] In step 708, the frame material is cooled to form a seal with the heater. Upon cooling, the frame material solidifies to form the heating unit. Once the frame material and heater are removed from the mold, the frame material may be actively cooled by quenching or passively cooled by allowing the frame material to reach ambient temperature.

[0043] In embodiments of the present invention in which the heater's interface features comprise holes, the above method may further include extending a fixed portion of the frame through one or more holes in the heater. This may be performed if the method starts with a solid frame material that already comprises protrusions, which are then heated to allow it to conform to the shape of the heater. In this example, the solid frame material and heater are brought together, and instead of the heated frame material being injected into the holes, the protrusions 111 of the solid frame material are inserted through the holes 110 in the heater. This step may be performed before the step of heating the frame material.

[0044] 8 is a schematic cross-sectional view of a method for forming lugs on a heating unit for an aerosol generating device in accordance with an embodiment of the present invention. In this example, a die 114 is provided to create lugs 112 by applying pressure to the ends of protrusions 111 protruding from holes 110 in either of the heating elements 102, 103.

Claims

1. a heater defining a heating chamber capable of receiving an aerosol-forming substrate, the heater being configured to be in direct contact with the aerosol-forming substrate when the aerosol-forming substrate is received within the heating chamber; a frame configured to only partially surround the heater, the frame being in thermal contact with the heater such that the frame is sealed to the heater; and A heating unit for an aerosol generating device comprising:

2. The heating unit of claim 1 , wherein the heater comprises one or more interface features configured to engage the frame.

3. The heating unit of claim 2 , wherein at least one of the one or more interface features comprises one or more holes disposed through the heater.

4. The heating unit of claim 3 , wherein the frame includes a fastening portion that extends through the one or more holes, thereby fastening the frame to the heater.

5. The heating unit of claim 4 , wherein the fixed portion comprises a lug.

6. The heating unit of any one of claims 1 to 5, wherein the frame comprises a thermoplastic material.

7. The heating unit of any preceding claim, wherein the heater comprises a ceramic.

8. 1. A method of forming a heating unit for an aerosol generating device, comprising: heating the frame material; sealing the frame material to the heater so as to only partially surround the heater, the heater defining a heating chamber capable of receiving an aerosol-generating substrate, the heater being configured to be in direct contact with the aerosol-generating substrate when the aerosol-generating substrate is received within the heating chamber; cooling the frame material to form a seal with the heater; A method comprising:

9. The method of claim 8 further comprising sealing the frame material to at least one of one or more bonding features of the heater.

10. 10. The method of claim 8 or claim 9, further comprising extending a fixed portion of the frame material through one or more holes in the heater prior to the heating step.

11. The method of claim 10 , wherein sealing the frame material to the heater comprises sealing the fixed portion of the frame material to the heater.

12. 10. A method of forming a heating unit according to claim 8 or 9, wherein the frame material is in the form of pellets prior to the heating step.

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