CN115886343A

CN115886343A - Heater for gas mist generating device, gas mist generating device and preparation method

Info

Publication number: CN115886343A
Application number: CN202110991880.3A
Authority: CN
Inventors: 武建; 徐中立; 李永海
Original assignee: Shenzhen FirstUnion Technology Co Ltd
Current assignee: Shenzhen FirstUnion Technology Co Ltd
Priority date: 2021-08-27
Filing date: 2021-08-27
Publication date: 2023-04-04

Abstract

The application provides a heater for an aerosol-generating device, an aerosol-generating device and a preparation method; wherein the aerosol-generating device comprises: a chamber for receiving an aerosol-generating article; a heater extending at least partially within the chamber and configured to heat the aerosol-generating article; the heater includes: a housing having a hollow extending in an axial direction; the hollow has a first opening and a second opening forming a housing surface; a resistive heating element located within the hollow; a thermal conductor formed by a precursor material that solidifies or cures after being injected into the void through the first opening for providing thermal conduction between the resistive heating element and the housing; the second opening is configured for air within the void to exit when the precursor material is injected through the first opening. Above aerial fog generating device, the heat conductor is solidified or is solidified after injecting the cavity by first opening and forms, and the second opening is used for keeping inside atmospheric pressure balanced with outside atmospheric pressure when the injection, can promote uniformity and yields in the preparation of mass production.

Description

Heater for gas mist generating device, gas mist generating device and preparation method

Technical Field

The embodiment of the application relates to the technical field of heating non-combustion smoking set, in particular to a heater for an aerosol generating device, the aerosol generating device and a preparation method.

Background

Smoking articles (e.g., cigarettes, cigars, etc.) burn tobacco during use to produce tobacco smoke. Attempts have been made to replace these tobacco-burning products by making products that release compounds without burning.

An example of such a product is a heating device that releases a compound by heating rather than burning the material. For example, the material may be tobacco or other non-tobacco products, which may or may not contain nicotine. In the known art, the 202010054217.6 patent proposes heating tobacco products with a heater enclosing a spiral heating wire within a metal outer sleeve to generate an aerosol. For the heater, the heat conduction and the insulation between the spiral heating wire and the metal outer sleeve are generally realized by adopting inorganic insulating glue or inorganic powder filled in the metal outer sleeve, so that the heat conduction and the insulation are realized, and the heat transfer between the heating wire and the outer sleeve is influenced by a large amount of pores in addition to the inevitable problems of powder falling and the like.

Disclosure of Invention

One embodiment of the present application proposes a heater for an aerosol-generating device, the heater comprising:

a housing configured as a pin or a needle or a cylinder or a rod and having a hollow extending in an axial direction; the hollow has a first opening and a second opening forming the housing surface;

a resistive heating element located within the void;

a thermal conductor formed from a precursor material that solidifies or cures after being injected into the void through the first opening for providing thermal conduction between the resistive heating element and the housing;

the second opening is configured to allow air within the void to exit when the precursor material is injected through the first opening.

In a more preferred embodiment, the first opening has an inner diameter of 0.5 to 3mm.

In a more preferred implementation, the housing has a free front end for insertion of an aerosol-generating article, and a terminal end opposite the free front end; wherein, the first and the second end of the pipe are connected with each other,

one of the first and second openings is near or at the free front end and the other is near or at the tip end.

In a more preferred implementation, the second opening is located at the end; the resistive heating element is received within the hollow through the second opening.

In a more preferred implementation, the resistive heating element is configured in the form of a helical coil extending along the hollow axis;

the cross-sectional area of the first opening is smaller than the cross-sectional area of the helical coil.

In a more preferred implementation, the resistive heating element comprises a hollow, axially extending resistive heating coil;

the first opening is formed on a side wall of the housing and avoids the resistive heating coil in the axial direction of the hollow.

In a more preferred embodiment, the thermal conductor includes at least one of silica or a precursor thereof, alumina or a precursor thereof, aluminate, aluminosilicate, aluminum nitride, aluminum carbide, zirconia, silicon carbide, silicon boride, silicon nitride, titanium dioxide, titanium carbide, boron oxide, borosilicate, silicate, rare earth oxide, soda lime, barium titanate, lead zirconate titanate, aluminum titanate, barium ferrite, strontium ferrite.

the cross section of the wire material of the helical coil is configured to extend a length in an axial direction of the helical coil greater than a length in a radial direction.

Yet another embodiment of the present application also provides an aerosol-generating device configured to heat an aerosol-generating article to generate an aerosol; the method comprises the following steps:

a chamber for receiving an aerosol-generating article;

a heater extending at least partially within the chamber and configured to heat an aerosol-generating article; characterized in that the heater comprises:

a housing having a hollow extending in an axial direction; the hollow has a first opening and a second opening forming the housing surface;

a resistive heating element located within the hollow;

Yet another embodiment of the present application also proposes a method of manufacturing a heater for an aerosol-generating device, comprising the steps of:

obtaining a housing and a resistive heating element; the housing having a hollow extending in an axial direction, the hollow having a first opening and a second opening forming a surface of the housing;

injecting a precursor material into the void through the first opening and solidifying or curing to form a thermally conductive body for providing thermal conduction between the resistive heating element and the housing; and allowing air within the void to exit the second opening when the precursor material is injected through the first opening.

Above aerial fog generating device, the heat conductor is solidified or is solidified after injecting the cavity by first opening and forms, and the second opening is used for keeping inside atmospheric pressure balanced when the injection, can promote uniformity and yields in the preparation of mass production.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.

Figure 1 is a schematic view of an aerosol-generating device provided by an embodiment of the present application;

FIG. 2 is a schematic cross-sectional view of a heater provided in one embodiment;

FIG. 3 is a schematic view of the heater housing of FIG. 2 from one perspective;

FIG. 4 is a schematic view of the electrical resistance heating element of FIG. 2 from one perspective;

FIG. 5 is a schematic cross-sectional view of the resistive heating coil of FIG. 4 from one perspective;

FIG. 6 is a schematic view of the structure of a resistive heating element according to yet another embodiment;

FIG. 7 is a schematic view of a method of making a heater according to one embodiment;

FIG. 8 is a schematic view of an embodiment of a resistive heating element embedded in a heater housing;

FIG. 9 is a schematic illustration of a heater housing of an embodiment with precursor feedstock injection;

FIG. 10 is a schematic illustration of the heater housing of FIG. 9 after injection of the precursor feedstock;

FIG. 11 is a cross-sectional electron micrograph of a heater made according to an example;

FIG. 12 is an enlarged view of a portion of FIG. 11;

FIG. 13 is an enlarged view of yet another portion of FIG. 11;

FIG. 14 is a sectional electron microscope image of a heater prepared in a comparative example;

FIG. 15 is an enlarged fragmentary view of FIG. 14;

FIG. 16 is an enlarged view of yet another portion of FIG. 14;

FIG. 17 shows a temperature profile of a heater of an embodiment in use;

FIG. 18 is a graph showing a temperature change curve of a heater in one comparative example in use;

FIG. 19 shows a schematic view of heater preparation in yet another embodiment;

FIG. 20 shows a schematic view of heater preparation in yet another embodiment;

FIG. 21 shows a schematic of heater preparation in yet another embodiment.

Detailed Description

To facilitate an understanding of the present application, the present application is described in more detail below with reference to the accompanying drawings and detailed description.

An embodiment of the present application provides an aerosol-generating device, the configuration of which can be seen in fig. 1, including:

a chamber within which an aerosol-generating article a is removably received;

a heater 30 extending at least partially within the chamber, the heater being inserted into the aerosol-generating article a to heat when the aerosol-generating article a is received within the chamber, such that the aerosol-generating article a releases a plurality of volatile compounds, and the volatile compounds are formed only by the heating process;

the battery cell 10 is used for supplying power;

a circuit 20 for conducting current between the cell 10 and the heater 30.

As further shown in figure 1, the chamber has an opening 40, through which opening 40, in use, an aerosol-generating article a can be removably received within the chamber.

In a preferred embodiment, the heater 30 is generally in the shape of a pin or needle, which in turn is advantageous for insertion into the aerosol-generating article a; meanwhile, the heater 30 may have a length of about 12 to 19 mm and an outer diameter of about 2 to 4 mm.

Further in alternative implementations, the aerosol-generating article a preferably employs a tobacco-containing material that releases volatile compounds from the substrate upon heating; or may be a non-tobacco material suitable for electrically heated smoking. The aerosol-generating article a preferably employs a solid substrate, which may comprise one or more of a powder, granules, shreds of pieces, strips or flakes of one or more of vanilla leaves, tobacco leaves, homogenised tobacco, expanded tobacco; alternatively, the solid substrate may contain additional tobacco or non-tobacco volatile flavour compounds to be released when the substrate is heated.

In practice, the heater 30 may generally include a resistive heating element, and an auxiliary substrate to assist in the securing or preparation of the resistive heating element, etc. For example, in some implementations, the resistive heating element is in the shape or form of a helical coil. Or in yet other implementations, the resistive heating elements are in the form of electrically conductive traces bonded to the substrate. Or in yet other implementations, the resistive heating element is in the shape of a substrate of a sheet.

Further figures 2-4 show a cross-sectional and partial component schematic view of a heater 30 in one embodiment, comprising:

a heater housing 31 configured in a pin or needle or rod or column shape of a hollow 311, and having a tapered tip at a front end for easy insertion into the aerosol-generating article a and an opening at a rear end for easy assembly of various functional components therein;

a resistance heating element 32 for generating heat after being energized; specifically, the resistance heating coil 320 configured in a spiral shape extending along a part of the axial direction of the heater housing 31, and a first conductive pin 321 connected to an upper end of the resistance heating coil 320, and a second conductive pin 322 connected to a lower end of the resistance heating coil 320, respectively, are structurally included. In use, first conductive pin 321 and second conductive pin 322 are used to deliver current to resistive heating coil 320.

Specifically, as shown in fig. 4, the first conductive pin 321 penetrates through the resistive heating coil 320 from the upper end of the resistive heating coil 320 and extends to the lower end of the resistive heating coil 320, so as to be connected to a circuit.

In the implementation shown in fig. 2, the resistive heating coil 320 is completely assembled and held within the hollow 311 of the heater housing 31, and the resistive heating coil 320 and the heater housing 31 are thermally conductive to each other after assembly.

In an alternative embodiment, the resistive heating coil 320 is made of a metal material, a metal alloy, graphite, carbon, a conductive ceramic or other ceramic material and metal material with appropriate impedance. Wherein suitable metal or alloy materials include at least one of nickel, cobalt, zirconium, titanium, nickel alloys, cobalt alloys, zirconium alloys, titanium alloys, nickel-chromium alloys, nickel-iron alloys, iron-chromium-aluminum alloys, iron-manganese-aluminum based alloys, or stainless steel, and the like.

The heater housing 31 is made of a heat conductive metal or alloy material, such as stainless steel. Of course, after assembly, the resistance heating coil 320 and the inner wall of the hollow 311 of the heater housing 31 are further thermally conductive to each other, while the heater housing 31 and the resistance heating coil 320 are insulated from each other.

Fig. 5 is a schematic cross-sectional view of the resistance heating coil 320 of fig. 4 from a perspective that the cross-sectional shape of the wire material of the resistance heating coil 320 is a wide or flat shape different from a conventional circular shape, i.e., the cross-sectional shape of the wire material has a greater length dimension latitudinally in one direction than another dimension latitudinally perpendicular thereto. For example, the cross-sectional shape of the wire material may be generally rectangular, diamond-shaped, polygonal, oval, kidney-shaped, or other irregular shape. In the preferred embodiment shown in fig. 3, the cross-section of the wire material of the resistance heating coil 320 has a dimension extending in the longitudinal direction larger than a dimension extending in a radial direction perpendicular to the longitudinal direction, so that the resistance heating coil 320 has a flat rectangular shape.

In brief, the resistive heating coil 320 constructed above is completely or at least flattened in the form of wire material, as compared to a conventional helical heating coil formed of a circular cross-section wire. Thus, the wire material extends to a lesser extent in the radial direction. By this measure, the energy loss in the resistive heating coil 320 can be reduced. In particular, the heat generated by the resistive heating coil 320 may be facilitated to be transferred radially toward the heater housing 31.

In an alternative implementation, the first conductive lead 321 and the second conductive lead 322 are made of a material with a low temperature coefficient of resistance. Meanwhile, the resistance heating coil 320 is made of a material having a relatively large positive or negative resistance temperature coefficient, so that the circuit 20 can obtain the temperature of the resistance heating coil 320 by detecting the resistance temperature coefficient of the resistance heating coil 320 in use.

In another preferred embodiment, the first conductive pin 321 and the second conductive pin 322 are made of two different materials selected from nickel, nichrome, nickel-silicon alloy, nickel-chromium-copper alloy, constantan, iron-chromium alloy, and other galvanic couple materials. A thermocouple for detecting the temperature of the resistive heating coil 320 is formed between the first and second conductive leads 321 and 322, and thus the temperature of the resistive heating coil 320 is obtained.

In other alternate implementations, the resistive heating coil 320 may also be formed from a conventional wire material having a circular cross-section. A resistance heating coil 320a such as a spiral coil made or constructed using a circular wire material in the resistance heating element 32a shown in fig. 6; and a first conductive pin 321a and a second conductive pin 322a are respectively connected to both ends of the resistive heating coil 320a for power supply or temperature measurement.

In yet another alternative implementation, such as shown in FIG. 2, the hollow 311 of the heater housing 31 is filled or encapsulated with a thermal conductor 33; on one hand, the heat conductor 33 fills the gap between the heater case 31 and the resistance heating coil 320/320a to improve the heat transfer efficiency between the resistance heating coil 320/320a and the heater case 31; in yet another aspect, the thermal conductor 33 provides insulation between the resistive heating coil 320/320a and the heater housing 31. At the same time, the thermal conductor 33 also provides retention for the resistive heating coil 320/320 a.

In practice, the resistive heating coil 320/320a is substantially completely encased or embedded within the thermal conductor 33.

In some preferred implementations, the material of the heat conductor 33 is preferably an inorganic oxide, carbide, nitride, or inorganic salt; for example, the material of the heat conductor 33 is at least one of glass glaze, alumina or its precursor, silica or its precursor, aluminate, aluminosilicate, aluminum nitride, aluminum carbide, zirconia, silicon carbide, silicon boride, silicon nitride, titanium dioxide, titanium carbide, boron oxide, borosilicate, silicate, rare earth oxide, soda lime, barium titanate, lead zirconate titanate, aluminum titanate, barium ferrite, strontium ferrite, or the like, which is relatively easy to obtain and manufacture. In yet another embodiment, the material of the thermal conductor 33 is further doped with a material with higher thermal conductivity, such as silicon carbide; so that the heat of the resistive heating coil 320/320a can be more rapidly transferred to the heater housing 31.

In yet another embodiment, the thermal conductor 33 has a melting point above 400 ℃ to avoid melting of the thermal conductor 33 when the heater 30 heats the aerosol-generating article a above a temperature of substantially 400 ℃. In a more preferred implementation, the thermal conductor 33 has a melting point of about 600-1500 ℃; preferably also 600 to 800 ℃.

As can be seen from the above, since the thermal conductor 33 is tightly combined with the heater housing 31 and/or the resistive heating coil 320/320a, no additional supporting or fixing structure is required to be added in the heater 30 to support or hold the resistive heating coil 320/320a and/or the thermal conductor 33.

As further shown in fig. 2 and 3, the free front end of the pin or needle or rod or cylinder shaped heater housing 31 is configured as a tapered tip, thereby being advantageous for insertion into the aerosol-generating article a. And the heater housing 31 is provided with an opening 313 at the free front end, which opening 313 serves, in use, as a passage for injecting a precursor material of the thermal conductor 33 into the hollow 311 of the heater housing 31; or the opening 313 may allow the injection end of the injection device to enter the heater housing 31.

In a further more preferred embodiment, the inner diameter of opening 313 is controlled to be about 0.5 to 3mm; preferably, the inner diameter of the opening 313 is about 1 to 2mm. It is advantageous for preventing the precursor raw material from leaking out from the opening 313 in the case where injection is performed.

In practice, the inner diameter of the opening 313 is smaller than the outer diameter of the resistance heating coil 320/320a, and the resistance heating coil 320/320a can be placed in the heater case 31 only through the opening 312 at the end, but not in the heater case 31 through the opening 313.

The opening 313 is formed by penetrating the outer surface of the heater case 31 to the inner wall surface of the hollow 311. In the preferred embodiment shown in fig. 2, the opening 313 is penetrated to the inner wall surface of the hollow 311 in the axial direction of the heater housing 31, or the opening 313 is penetrated to the inner wall surface of the hollow 311 in the radial direction of the heater housing 31. In other implementations, the opening 313 is located proximate to the tip of the heater housing 31.

In some implementations, the opening 313 is formed by perforating the heater housing 31; or in yet other variations, opening 313 is formed by cutting or chipping off the tapered tip portion of heater housing 31.

Still another embodiment of the present application also proposes a method of manufacturing the above heater 30, as shown in fig. 7, including the steps of:

s10, obtaining a heater shell 31 and a resistance heating coil 320/320a made of resistive metal or alloy material; of course, as described above, the heater housing 31 is a pin or needle or cylinder or rod with an axial hollow 311, preferably made of metal or alloy such as grade 430 stainless steel (SS 430); at the same time, the resistive heating coil 320/320a is placed into the hollow 311 of the heater case 31 from the opening 312 of the end of the heater case 31, as shown in fig. 8.

S20, injecting a precursor raw material 33a forming a heat conductor 33 into the hollow 311 from an opening 313 at the free front end of the heater shell 31;

in practice, the precursor material 33A is prepared by mixing the above-mentioned material materials for forming the thermal conductor 33 with a high-temperature resistant organic or inorganic paste (e.g., a commercially available epoxy ceramic paste, an inorganic paste disclosed in CN113121193A, a commercially available inorganic ceramic paste, etc.) to form a paste or paste-like feedstock having a suitable fluidity, and injecting the mixture into the hollow 311 of the heater housing 31 by injection. In some implementations, the injection may be performed using a syringe C or the like commonly used in injection molding processes, as shown in fig. 9 and 10.

Compared with the conventional way of injecting directly from the opening 312 at the end of the heater housing 31, in this implementation, the precursor raw material 33a is injected through the opening 313 at the free front end of the heater housing 31, on one hand, the precursor raw material 33a occupies the space of the hollow 311 from bottom to top in fig. 9 step by step, effectively suppressing bubbles or voids generated by the injection operation; on the other hand, the air in the hollow 311 can be discharged from the opening 312 at the end, so that the air pressure in the hollow 311 is always the same as the external air pressure, and the generation of air holes or voids due to the change in air pressure is reduced.

And S30, finally, solidifying or solidifying the injected precursor raw material 33a in the figure 10 to form a heat conductor 33 by means of natural cooling or cooling, namely obtaining the heater 30 shown in the figure 2.

In still other variations, the precursor material 33a in step S20 is a slurry, paste or paste feed material with appropriate fluidity formed by mixing raw material powder of the thermal conductor 33 in combination with organic liquid auxiliaries (e.g., common carrier solvents, dispersants, leveling agents, etc.); and then can be injected into the hollow 311 of the heater housing 31 through the opening 313 at the free front end. Alternatively, in still another modified implementation, the above precursor raw material 33a is a raw material in a powder state, such as glaze powder, alumina powder, or the like, directly filled into the hollow 311 of the heater housing 31 by a powder filling apparatus.

In a more preferred embodiment, the precursor material 33a may be preheated in advance to be softened or melted to improve the fluidity during the process of injecting the precursor material 33a into the heater housing 31 through the opening 313 in step S20. In general practice, the precursor feedstock 33a is heated to a softening temperature of about 150 ℃ to about 300 ℃. Heating the precursor material 33a to a molten state is performed in correspondence with the melting point of the material selected for the precursor material 33a, so that it is completely converted to a molten state; of course, in the case where the precursor raw material 33a is heated to a molten state at a high temperature, it is necessary to ensure that the high-temperature-resistant organic glue used for the above feeding can withstand the temperature to be carried out without causing pyrolysis or aging failure.

In some implementations, the precursor feedstock 33a is typically preheated to 150 ℃ to 300 ℃ and injected as an injection temperature.

In a further more preferred implementation, the injection pressure in the injection molding process in step S20 is 30 to 150MPa, and the injection speed is 5 to 80g/S, so that the precursor raw material 33a is injected substantially uniformly, which is advantageous in reducing as much as possible the generation of bubbles or voids during the injection process.

In a preferred embodiment, an insulating layer or a protective layer is formed by spraying, depositing, or the like on the surface of the resistance heating coil 320/320a before dipping the resistance heating coil 320/320a into the heater housing 31 having the precursor raw material 33a; such as a glaze layer, etc. Or in yet another preferred embodiment, before dipping the resistance heating coil 320/320a into the heater housing 31 having the precursor raw material 33a, it is advantageous to further improve the insulation effect by supplying power to the resistance heating coil 320/320a to heat the resistance heating coil 320/320a in air or an oxygen-containing atmosphere, thereby thermally oxidizing the surface of the resistance heating coil 320/320a to form a metal oxide layer on the surface.

In a further preferred embodiment, the heat conductor 33 is made of a material having a lower melting point, based on the fact that the heater housing 31 is made of stainless steel. In the most preferred implementation, the thermal conductor 33 is glass or silica or glaze or alumina ceramic or the like. Their raw material powders are mixed with an organic auxiliary agent to prepare precursor raw material 33a during the preparation.

Further in the above embodiment, the heat conductor 33 formed by solidification or solidification after injection through the opening 313 can substantially completely penetrate into the gap or clearance between the inner wall of the heater case 31 and the resistance heating coil 320/320a, and the heat conductor 33 can substantially safely bring the inner wall of the heater case 31 and the resistance heating coil 320/320a into a non-contact state, thereby substantially completely insulating them from each other; the adoption of the preparation steps can improve the insulation consistency and the yield in mass production and preparation.

In the above preparation, it is also possible to make the heat conductor 33 have a small gap with the resistance heating coil 320/320a and to eliminate bubbles generated in the heat conductor 33 due to injection or expansion of organic/inorganic paste, which is advantageous for improving the heat capacity and heat conduction of the heater 30 and reducing temperature fluctuation during heating.

A schematic view of a heater 30 is prepared, for example, in yet another alternate implementation shown in fig. 19; in this embodiment, an opening 313b is formed in a side wall of a pin-shaped or needle-shaped or rod-shaped or columnar heater case 31b, and the opening 313b is near the front end of the heater case 31b and serves as an injection passage for an injection device such as a syringe C to inject a precursor raw material 33a; and the opening 312b of the heater housing 31b at the distal end serves as a passage for air within the hollow 311b to be discharged during injection; thereby balancing the pressure difference between the hollow 311b and the outside during injection, preventing air from entering the precursor material 33a due to the pressure difference, and eliminating the generation of bubbles and the like. The precursor raw material 33a is injected into the hollow 311b through the opening 313b, and is cooled and solidified or solidified inside the heater case 31b to form a heat conductor, thereby obtaining the heater prepared in this example.

Or a schematic of a heater in yet another alternative implementation is shown, for example, in fig. 20; in this embodiment, an opening 313c is formed on a side wall of the heater case 31c near the distal end, which is in the shape of a pin or a needle or a rod or a column; an opening 314c is formed at a position of the free front end of the heater case 31c by punching, cutting, or the like. Then in use, the resistive heating coil 320c is placed into the hollow 311c of the heater housing 31c through the opening 312c of the tip; the opening 313C serves as an injection passage through which an injection device such as a syringe C injects the precursor raw material 33a; the opening 314c serves as a passage for air within the hollow 311c to escape during injection. The precursor raw material 33a is injected into the hollow 311c from the opening 313c, and then cooled, solidified or solidified to form the heat conductor 33, i.e., the heater prepared in this example is obtained. Of course in this embodiment, the distal opening 312c is sealed by a flexible sealing plug D to prevent leakage of the precursor source 33a from the opening 312c during injection; while the sealing plug D is removed after the precursor material 33a has cured to form the thermal conductor 33.

Or a schematic of the heater in yet another alternative implementation is shown, for example, in fig. 21; the heater case 31d in this embodiment has a tubular shape, and a tubular hollow 311d thereof forms an opening 312d and an opening 313d at the distal end and the free front end, respectively. In use, the resistive heating coil 320d is placed into the hollow 311d of the heater housing 31d through the opening 312d of the distal end; the opening 313d serves as an injection passage port through which the precursor raw material 33a is injected by an injection device such as a syringe C, while the opening 312d serves as a passage through which air in the hollow 311d is discharged during injection. Of course in this embodiment, the gap between the opening 313D and the needle of the syringe C is sealed by a flexible sealing plug D to prevent leakage therebetween during injection; while the sealing plug D is removed after the precursor material 33a has cured to form the thermal conductor 33.

Further as can be seen from the sectional views of the respective embodiments, the openings 313/313b/313c/313d for performing the injection of the precursor raw material 33a are located outside the extension area of the resistance heating coil 320/320b/320c/320d in the axial direction of the heater 30; it is advantageous to avoid bubbling of the precursor feedstock 33a by direct jet impingement onto the resistive heating coils 320/320b/320c/320 d.

It can further be seen from the above embodiments that the openings for injection and the openings for air escape are located substantially at the free front and end of the heater 30, respectively; it is convenient in practice for the heater casing 31/31b/31c/31d to be held vertically by jigs or clamps. During the injection operation, the heater housings 31/31b/31c/31d are held in such a way that the injection opening is below the opening for air to escape, and it is advantageous that the precursor feedstock 33a gradually fills up under gravity during the injection.

Further in a typical implementation, the gap or clearance between the opening for injection and the needle of the syringe C may be sealed by a jig or sealing material to prevent leakage from the gap or clearance of their holder during injection.

Further shown in fig. 11-13 are cross-sectional electron micrographs of precursor raw materials 33a prepared in one embodiment as a mixture of glass frit and epoxy organic glue, heater 30 with resistive heating coils 320/320a prepared by the steps of the above fig. 9 embodiment. As can be seen, the resistive heating coil 320/320a is substantially completely encased within the thermal conductor 33; and there is no contact between the resistive heating coil 320/320a and the metallic heater case 31.

In order to highlight the microscopic quality of the heater 30 prepared above, fig. 14 to 16 show cross-sectional electron micrographs of a heater 30 prepared in a comparative example by injecting a precursor raw material 33a mixed with glass frit and an organic glue of epoxy resin through an opening 312 of a heater case 31 having only a distal end.

As is apparent from the sectional electron microscope images of the heater 30 prepared in the embodiment of fig. 12 and 13, the resistive heating coil 320/320a has a very small interfacial gap with the heat conductor 33; of course, the scattered pores or bubbles in the thermal conductor 33 are caused by the expansion of the organic glue in the feed. In contrast, in the sectional electron microscope images of the heater 30 prepared by gluing in fig. 15 and 16, the interface gap between the resistance heating coil 320/320a and the heat conductor 33 is larger, and has a larger black shadow under the electron microscope. Meanwhile, it is conspicuously seen in fig. 15 and 16 that the heat conductor 33 has more interface cracks inside.

FIG. 17 shows the temperature profile of a heater during use, the heater being prepared according to the embodiment shown in FIG. 9; i.e., a precursor raw material 33a prepared by mixing glass frit and epoxy resin organic paste, the precursor raw material 33a is injected into the gap between the heater case 31 and the resistance heating coil 320/320a through the opening 313. FIG. 18 shows the temperature profile of a heater in a comparative example, which is prepared by injecting precursor raw materials from the heater case having only an opening at the end and then directly curing by blowing air using a heat gun, during use. The curves in use are all power supplied by high-precision PID software control, and fluctuation of actual working temperature is further sampled.

As can be seen from the graph, the temperature jump of the heater 30 prepared in the embodiment shown in fig. 17 is relatively small during the heating process, the temperature jump amplitude during the heating process is about 20 to 35 ℃, and the curve during the constant temperature heating process is relatively flat; the heater of the comparative example shown in fig. 18 has a relatively large temperature feedback during operation and a relatively large temperature jump during heating, approximately 30 to 50 ℃.

It should be noted that the preferred embodiments of the present application are shown in the specification and the drawings, but the present application is not limited to the embodiments described in the specification, and further, it will be apparent to those skilled in the art that modifications and variations can be made in the above description, and all such modifications and variations should be within the scope of the appended claims of the present application.

Claims

1. A heater for an aerosol-generating device, the heater comprising:

a housing configured in a pin or needle shape or a column or rod shape and having a hollow extending in an axial direction; the hollow has a first opening and a second opening forming the housing surface;

a resistive heating element located within the hollow;

a thermal conductor formed from a precursor material that solidifies or cures after injection into the void through the first opening for providing thermal conduction between the resistive heating element and the housing;

2. A heater for an aerosol-generating device according to claim 1, wherein the first opening has an internal diameter of 0.5 to 3mm.

3. A heater for an aerosol-generating device according to claim 1 or 2, wherein the housing has a free front end for insertion of an aerosol-generating article and a terminal end opposite the free front end; wherein the content of the first and second substances,

one of the first and second openings is located near or at the free front end and the other is located near or at the tip end.

4. A heater for an aerosol-generating device according to claim 3, wherein the second opening is located at the tip; the resistive heating element is received within the hollow through the second opening.

5. A heater for an aerosol-generating device according to claim 1 or 2, wherein the resistive heating element is configured in the form of a helical coil extending along the hollow axis;

6. A heater for an aerosol-generating device according to claim 1 or 2, wherein the resistive heating element comprises a hollow, axially extending resistive heating coil;

the first opening is formed on a side wall of the housing and avoids the resistance heating coil in an axial direction of the hollow.

7. A heater for an aerosol-generating device according to claim 1 or 2, wherein the thermal conductor comprises at least one of silica or a precursor thereof, alumina or a precursor thereof, an aluminate, an aluminosilicate, aluminum nitride, aluminum carbide, zirconia, silicon carbide, silicon boride, silicon nitride, titanium dioxide, titanium carbide, boron oxide, a borosilicate, a silicate, a rare earth oxide, soda lime, barium titanate, lead zirconate titanate, aluminum titanate, barium ferrite, strontium ferrite.

8. A heater for an aerosol-generating device according to claim 1 or 2, wherein the resistive heating element is configured in the form of a helical coil extending along the hollow axis;

9. An aerosol-generating device configured to heat an aerosol-generating article to generate an aerosol; the method comprises the following steps:

a chamber for receiving an aerosol-generating article;

a heater extending at least partially within the chamber and configured to heat an aerosol-generating article;

characterized in that the heater comprises:

a resistive heating element located within the hollow;

10. A method of making a heater for an aerosol-generating device, comprising the steps of:

injecting a precursor material into the void through the first opening and solidifying or curing to form a thermal conductor for providing thermal conduction between the resistive heating element and the housing; and allowing air within the void to exit from the second opening upon injection of the precursor material through the first opening.