Steam supply system

Abstract

A novel vaporizer assembly for use in a vapor delivery system is provided. The present invention relates to a vaporizer assembly for use in a vapor delivery system, comprising a liquid transfer element formed from cotton and a heating element including a coil of resistance wire surrounding a portion of the liquid transfer element, the heating element having an electrical resistance between 1.3 and 1.5 ohms. Preferably, the heating element has an electrical resistance selected from the group consisting of greater than 1.32 ohms, greater than 1.34 ohms, greater than 1.36 ohms, and greater than 1.38 ohms.

Description

[Technical Field]

[0001] This disclosure relates to vapor supply systems such as nicotine delivery systems (e.g., e-cigarettes and similar devices). [Background technology]

[0002] Electronic vapor supply systems, such as e-cigarettes, generally contain a vapor precursor material, such as a reservoir of a source liquid typically containing a nicotine-containing formulation, from which vapor is produced for inhalation by the user, for example, through thermal vaporization. Therefore, a vapor supply system typically comprises a vaporization chamber containing a vaporizer assembly positioned to vaporize a portion of the precursor material and generate vapor within the vaporization chamber. The vaporizer assembly often comprises a heater coil positioned around a liquid transfer element (capillary wick) that is configured to transfer the source liquid from the reservoir to the heater coil for vaporization. When the user inhales the device and power is supplied to the vaporizer assembly, air is drawn into the device through an inlet hole and enters the vaporization chamber, where the air mixes with the vaporized precursor material to form a condensed aerosol. An air channel connects the vapor generation chamber to the opening in the mouthpiece. As a result, air inhaled through the vapor generation chamber travels along the channel to the mouthpiece opening when the user inhales into the mouthpiece, carrying vapor for the user's inhalation along with the air.

[0003] The design of aspects related to the vaporizer assembly of a steam supply system can play a crucial role in the overall operation of the system, for example, by helping to reduce leakage, by helping to achieve a desired level of steam generation, and by helping to reduce the possibility of overheating, which can result in undesirable flavoring due to insufficient replenishment of the vaporized liquid. Various methods that seek to help address some of these challenges are described below in this document. [Overview of the Initiative]

[0004] According to a first aspect of a particular embodiment, a vaporizer assembly is provided for use in a steam supply system, the vaporizer assembly comprising a liquid transfer element formed from cotton and a heating element comprising a coil of resistance wire surrounding a portion of the liquid transfer element, the heating element having an electrical resistance between 1.3 and 1.5 ohms.

[0005] According to a second aspect of a particular embodiment, a device is provided comprising the vaporizer assembly of the first aspect of a particular embodiment and a reservoir for a raw material liquid, wherein a liquid transfer element is arranged to draw the raw material liquid from the reservoir to a heating element for heating to generate vapor for inhalation by the user.

[0006] According to a third aspect of a particular embodiment, a vaporizer assembly means for use in a steam supply means is provided, which comprises a liquid transfer means formed from cotton and a heating element including a coil made of resistance wire surrounding a portion of the liquid transfer means, the heating element having an electrical resistance between 1.3 and 1.5 ohms.

[0007] According to a fourth aspect of a particular embodiment, a method is provided for manufacturing a vaporizer assembly for use in a steam supply system, the method comprising the steps of supplying a liquid transfer element and forming a heating element including a coil of resistance wires surrounding a portion of the liquid transfer element, the heating element having an electrical resistance between 1.3 and 1.5 ohms.

[0008] In relation to the various aspects of this disclosure, it should be understood that the features and aspects of the present invention described herein are equally applicable to, and may be combined with, other embodiments of the disclosure as needed, as well as the specific combinations described herein.

[0009] Next, embodiments of the present invention will be described only as examples with reference to the attached drawings. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic perspective view showing a steam supply system comprising a cartridge and a control unit (shown separately) according to a particular embodiment of the present disclosure. [Figure 2] Figure 1 is a schematic disassembled perspective view showing the components of the cartridge in the steam supply system. [Figure 3A] Figure 1 is a schematic cross-sectional view showing the housing portion of the cartridge of the steam supply system. [Figure 3B] This is another schematic cross-sectional view showing the housing portion of the cartridge of the steam supply system shown in Figure 1. [Figure 3C] This is yet another cross-sectional view schematically showing the housing portion of the cartridge of the steam supply system in Figure 1. [Figure 4] This flowchart schematically illustrates the steps of a method for forming a material for use as a liquid transfer element in a steam supply system according to one embodiment of the present disclosure. [Figure 5] This is a schematic flowchart illustrating the steps of a method for forming a vaporizer assembly for use in a steam supply system according to one embodiment of the present disclosure. [Figure 6] This figure schematically shows a vaporizer assembly according to one embodiment of the present disclosure. [Figure 7] Figures 1 and 2 are graphs that schematically show the amount of steam generated by the types of steam supply systems shown, for different wick materials and various different coil resistances. [Modes for carrying out the invention]

[0011] This document discusses and explains the aspects and features of specific examples and embodiments. Some aspects and features of these specific examples and embodiments can be implemented conventionally, and for the sake of brevity, they are not discussed or explained in detail. Therefore, please understand that aspects and features of apparatus and methods mentioned in this document but not described in detail can be implemented by any conventional method for carrying out such aspects and features.

[0012] The present disclosure relates to a vapor supply system, sometimes also referred to as an aerosol supply system, such as an e-cigarette. Throughout the following description, the term "e-cigarette" or "electronic cigarette" may be used, but it should be understood that this term can be used interchangeably with vapor supply systems / devices and electronic vapor supply systems / devices. Further, as is common in the art, the terms "vapor" and "aerosol", as well as related terms such as "vaporization", "volatilization" and "aerosolization", can generally be used interchangeably.

[0013] A vapor supply system (e-cigarette) often, though not always, comprises a modular assembly that includes both a reusable part (control unit part) and a replaceable (disposable) cartridge part. Often, the replaceable cartridge part comprises the vapor precursor material and vaporizer assembly, while the reusable part comprises the power supply (e.g., a rechargeable battery) and control circuitry. It will be understood that these different parts may have additional elements depending on their functionality. For example, the reusable device part may have a user interface for receiving user input and displaying operating status characteristics, and the replaceable cartridge part may have a temperature sensor to assist in temperature control. The cartridge is electrically and mechanically coupled to the control unit for use, for example, using screw, latch, or bayonet fasteners with appropriately engaging electrical contacts. If the vapor precursor material in the cartridge is depleted, or if the user wishes to replace it with a different cartridge having a different vapor precursor material, the cartridge may be removed from the control unit and a replacement cartridge installed in its place. Devices that conform to this type of two-part modular configuration may generally be referred to as two-part devices. Electronic cigarettes generally have an elongated shape. To provide concrete examples, the specific embodiments of the disclosure described herein should be understood to include this type of generally elongated two-part device utilizing a disposable cartridge. However, it should be understood that the basic principles described herein can be equally applied to different electronic cigarette configurations, such as single-part devices, modular devices having two or more parts, refillable devices and single-use disposable devices, and devices that conform to other overall shapes, such as so-called box-mod high-performance devices, which typically have a more box-like shape.More generally, certain embodiments of the present disclosure are based on techniques intended to assist in the optimal operation of the vaporizer assembly of a vapor supply system according to the principles described herein, and other structural and functional aspects of an electronic cigarette that implement the techniques according to certain embodiments of the present disclosure are not of primary importance and can be realized, for example, by any established technique.

[0014] FIG. 1 is a schematic perspective view of an exemplary vapor supply system / device (e-cigarette) 1 according to certain embodiments of the present disclosure. Positional terms (e.g., terms such as above, below, upper, lower, top, bottom, etc.) regarding the relative positions of various aspects of the electronic cigarette can be used herein based on the orientation of the electronic cigarette shown in FIG. 1 (unless otherwise specified). However, it should be understood that this is merely for ease of explanation and does not indicate that any particular orientation is required for use of the electronic cigarette.

[0015] The e-cigarette 1 includes two main components, namely a cartridge 2 and a control unit 4. The control unit 4 and the cartridge 2 are shown separately in FIG. 1 but are coupled during use.

[0016] The cartridge 2 and the control unit 4 are coupled by establishing mechanical and electrical connections between them. The specific method by which the mechanical and electrical connections are established is not of primary importance to the principles described herein and can be established by conventional techniques, for example, based on screw-type, bayonet-type, latch-type, or friction-fit mechanical fastening means having appropriately positioned electrical contacts / electrodes for establishing electrical connections between the two parts as needed. In the exemplary e-cigarette 1 shown in Figure 1, the cartridge comprises a mouthpiece end 52 and an interface end 54 and is coupled to the control unit by inserting the interface end portion 6 of the cartridge into the corresponding receptacle 8 / receptacle of the control unit. The interface end portion 6 of the cartridge is a press-fit portion for the receptacle 8 and includes a projection 56, which engages with a corresponding stopper portion on the inner surface of the receptacle wall 12 that defines the receptacle 8 to form a releasable mechanical engagement portion between the cartridge and the control unit. An electrical connection is established between the control unit and the cartridge via a pair of electrical contacts at the bottom of the cartridge (not shown in Figure 1) and corresponding spring-loaded contact pins at the base of the receptacle 8 (not shown in Figure 1). As described above, the specific manner in which the electrical connection is established is not important to the principles described herein, and in fact, in some embodiments, there may be no electrical connection at all between the cartridge and the control unit, for example, since the power can be transmitted wirelessly from the reusable part to the cartridge (for example, based on electromagnetic induction techniques).

[0017] The e-cigarette 1 has a substantially elongated shape extending along its longitudinal axis L. When the cartridge is coupled to the control unit, the total length of the e-cigarette (along the longitudinal axis) in this example is approximately 12.5 cm. The total length of the control unit is approximately 9 cm, and the total length of the cartridge is approximately 5 cm (i.e., when they are coupled, there is an overlap of approximately 1.5 cm between the interface end portion 6 of the cartridge and the receptacle 8 of the control unit). The e-cigarette has a substantially elliptical cross-section, which is widest near the middle of the e-cigarette and tapers towards the end in a curved manner. The cross-section near the middle of the e-cigarette has a width of approximately 2.5 cm and a thickness of approximately 1.7 cm. The end of the cartridge has a width of approximately 2 cm and a thickness of approximately 0.6 cm, while the other end of the e-cigarette has a width of approximately 2 cm and a thickness of approximately 1.2 cm. The outer housing of the e-cigarette is formed from plastic in this example. Please understand that the specific size and shape of the e-cigarette, and the materials used to make it, are not primarily important to the principles described in this book and may differ in other embodiments. In other words, the principles described in this book can be similarly applied to e-cigarettes of different sizes, shapes, and / or materials.

[0018] The control unit 4 according to certain embodiments of this disclosure may be generally conventional in terms of its function and general construction techniques. In the example of Figure 1, the control unit 4 comprises a plastic outer housing 10 including a receptacle wall 12, the receptacle wall defining a receptacle 8 for receiving the end of the cartridge as described above. The outer housing 10 of the control unit 4 in this example has a substantially elliptical cross-section at its interface portion that matches the shape and size of the cartridge 2, with a smooth transition between these two portions. Since the receptacle 8 and the end 6 of the cartridge 2 are symmetrical when rotated 180°, the cartridge can be inserted into the control unit in two different orientations. It should be noted that in some embodiments, there can be no degree of rotational symmetry such that the cartridge can only be connected to the control unit in one orientation, while in other embodiments, there can be a high degree of rotational symmetry such that the cartridge can be connected to the control unit in more orientations. The receptacle wall 12 includes two control unit air inlet openings 14 (i.e., holes in the wall). When the user inhales the device during use, air is drawn through these holes and along the gaps between the cartridge portion 2 and the receptacle wall 12 located next to the flat portion 7 of the cartridge portion, towards the interface end of the cartridge portion 54, where the air enters the cartridge through the opening at the base end of the cartridge (the air inlet to the cartridge is not visible in Figure 1). It should be understood that, even away from the flat portion 7, some of the drawn-in air may also be drawn into the cartridge through the gap between the cartridge and the control unit 4, since the interface end portion 6 of the cartridge 2 does not form an hermetically sealed airtight seal with the receptacle wall 12.

[0019] The control unit further includes a battery 16 that supplies power to the e-cigarette, a control circuit 18 for controlling and monitoring the operation of the e-cigarette, a user input button 20, an indicator light 22, and a charging port 24.

[0020] In this example, the battery 16 is rechargeable and can be a conventional type, such as those commonly used in e-cigarettes and other applications requiring a relatively high current supply over a relatively short period. The battery 16 can be recharged via a charging port 24, which may include, for example, a USB connector.

[0021] In this example, the input button 20 is a conventional mechanical button having a spring-loaded component that can be pressed by a user, for example, to make electrical contact with a lower circuit. In this regard, the input button may also be considered an input device that detects input from a user to initiate steam generation, for example, and the specific way in which the button is implemented is not important. For example, other forms of mechanical buttons or touch-sensitive buttons (e.g., based on capacitive or optical sensing techniques) may be used in other embodiments, or there may be no button at all, and the device may also rely on a puff detector to initiate steam generation.

[0022] The indicator light 22 is provided to give the user a visual indication of various characteristics related to the e-cigarette, such as the operating status (e.g., on / off / standby), and other characteristics such as battery life or fault status. Various characteristics may be indicated, for example, by various colors and / or various flashing sequences using common conventional techniques.

[0023] The control circuit 18 is appropriately configured / programmed to control the operation of the e-cigarette to realize conventional operating functions in accordance with established techniques for controlling e-cigarettes. The control circuit (processor circuit) 18 can be thought of as logically comprising various subunits / circuit elements related to various aspects of the operation of the e-cigarette. For example, depending on the functions provided in different embodiments, the control circuit 18 may include a power control circuit for controlling the power supply from the battery to the cartridge in response to user input, a user programming circuit for establishing configuration settings (e.g., user-defined power settings) in response to user input, as well as other functional units / circuits related to the functions according to the principles described herein, and conventional operating aspects of the e-cigarette such as an indicator light display drive circuit and a user input detection circuit. It should be understood that the functions of the control circuit 18 can be provided in various different ways, for example, using one or more appropriately programmed programmable computers and / or one or more appropriately configured application-specific integrated circuits / circuits / one or more chips / one or more chipsets configured to provide the desired functions.

[0024] Figure 2 is an exploded perspective view of cartridge 2 (disassembled along the longitudinal axis L). Cartridge 2 comprises a housing portion 32, an air channel sealing portion 34, an outlet pipe 38, a vaporizer assembly 36 including a heater 40 and a liquid transfer element 42, an elastic plug 44, and an end cap 48 having a contact electrode 46.

[0025] Figure 3A is a schematic cross-sectional view of the housing portion 32 along the longitudinal axis L at the thinnest point of the housing portion 32. Figure 3B is a schematic cross-sectional view of the housing portion 32 along the longitudinal axis L at the widest point of the housing portion 32. Figure 3C is a schematic view of the housing portion along the longitudinal axis L, from the interface end 54 (i.e., viewed from below in the orientation of Figures 3A and 3B).

[0026] The housing portion 32 in this example comprises a housing outer wall 64 and a housing inner tube 62, which in this example are formed from a single molded polypropylene piece. The housing outer wall 64 defines the appearance of the cartridge 2, and the housing inner tube 62 defines the portion through which the air channel penetrates the cartridge. The housing portion is open at the interface end 54 of the cartridge and closed at the mouthpiece end 52 of the cartridge, except for a mouthpiece opening / vapor outlet 60 which is in fluid communication with the housing inner tube 62. The outer wall 64 of the housing portion 32 has a hole which becomes a latch recess 68 positioned to receive the corresponding latch projection 70 of the end cap 48 when the cartridge is assembled, and to secure the end cap to the housing portion.

[0027] The air channel seal 34 is a substantially tubular silicone molded part having a through hole 80. The outer wall of the air channel seal 34 includes an annular ridge 84 and an upper collar 82. The inner wall of the air channel seal 34 also includes an annular ridge, but these are not visible in Figure 2. When the cartridge is assembled, the air channel seal 34 is attached to the inner housing tube 62 with one end of the inner housing tube 62 extending partially into the through hole 80 of the air channel seal 34. The through hole 80 of the air channel seal has a diameter of approximately 5.8 mm in its relaxed state, while the end of the inner housing tube 62 has a diameter of approximately 6.2 mm, thereby forming a seal when the air channel seal 34 is stretched to receive the inner housing tube 62. This seal is facilitated by the ridge on the inner surface of the air channel seal 34.

[0028] The outlet tube 38 comprises a tubular section of ANSI 304 stainless steel with an inner diameter of approximately 8.6 mm and a wall thickness of approximately 0.2 mm. The lower end of the outlet tube 38 includes a pair of diametrically opposed slots 88, the ends of which have semicircular recesses 90. When the cartridge is assembled, the outlet tube 38 fits onto the outer surface of the air channel seal 34. The outer diameter of the air channel seal is approximately 9.0 mm in its relaxed state, so that when the air channel seal 34 is compressed and fitted into the interior of the outlet tube 38, a seal is formed. This seal is enhanced by a ridge 84 on the outer surface of the air channel seal 34. A collar 80 of the air channel seal 34 acts as a stopper for the outlet tube 38.

[0029] The liquid transfer element 42 includes a capillary wick, and the heater 40 includes a resistance wire wound around the capillary wick.

[0030] In addition to the portion of resistance wire wound around the capillary wick 42 that becomes the heater 40, the vaporizer assembly 36 further comprises electrical lead wires 41, which pass through a through-hole in the elastic plug 44 to a contact electrode 46 attached to the end cap 54, allowing power to be supplied to the heater 40 via an electrical interface established when the cartridge is connected to the control unit. The heater lead wires 41 may contain the same material as the resistance wire wound around the capillary wick to form the heater 40, but in this example the heater lead wires 41 contain a different material (low-resistance material) connected to the heater resistance wire wound around the capillary wick. In this example the heater 40 contains nickel-chromium (nichrome) alloy wire, the wick 42 contains organic cotton, and the heater lead wires 41 contain N6 nickel wire soldered to each end of the heater coil 40 at a solder joint 43. Some further aspects and features of vaporizer assemblies according to other embodiments of the present disclosure are described below.

[0031] When the cartridge is assembled, the wick 42 is received in the semicircular recess 90 of the outlet tube 38, so that the center of the wick around which the heating coil is wound is inside the outlet tube and the ends of the wick are outside the outlet tube 38.

[0032] The elastic plug 44 in this example comprises a single molded part of silicone. The elastic plug comprises a base portion 100 having an outer wall 102 and an inner wall 104 extending upward from the base portion 100 and surrounding a central through-hole (not visible in Figure 2) passing through the base portion 100. When the cartridge is assembled and in use, air entering the cartridge through the opening of the end cap 54 passes through the central through-hole of the elastic plug 44 and is drawn near the heater 40 of the vaporizer assembly 36.

[0033] The outer wall 102 of the elastic plug 44 matches the inner surface of the housing portion 32, thereby forming a seal between the elastic plug 44 and the housing portion 32 when the cartridge is assembled. The inner wall 104 of the elastic plug 44 matches the inner surface of the outlet tube 38, thereby forming a seal between the elastic plug 44 and the outlet tube 38 when the cartridge is assembled. The inner wall 104 includes a pair of diametrically opposed slots 108, the ends of which have semicircular recesses 110. A cradle section 112, shaped to receive a section of the liquid transfer element 42 when the cartridge is assembled, extends outward from the bottom of each slot in the inner wall 104 (i.e., away from the longitudinal axis of the cartridge). The slot 108 and semicircular recess 110 on the inner wall of the elastic plug 44 are aligned with the slot 88 and semicircular recess 90 of the outlet pipe 38, so that the slot 88 of the outlet pipe 38 cooperates to define a hole through which the liquid transfer element 42 passes, corresponding each of the cradles 112 to the respective semicircular recesses of the outlet pipe and the elastic plug. The size of the hole formed by the semicircular recess through which the liquid transfer element passes closely corresponds to the size and shape of the liquid transfer element, but is slightly smaller and is compressed to some extent by the elasticity of the elastic plug 44. This allows the liquid to be transferred along the liquid transfer element by capillary action, while limiting the extent to which liquid not transferred by capillary action can pass through the opening. As described above, the elastic plug 44 further includes an opening in the base portion 100 through which the contact lead wires 41 of the heater coil 40 pass when the cartridge is assembled. In this example, the lower part of the base portion of the elastic plug includes spacers 116 that maintain an offset between the remaining surface of the lower part of the base portion and the end cap 48. These spacers 116 include openings through which the electrical contact leads 41 of the heater coil pass.

[0034] The end cap 48 includes a polypropylene molded part to which a pair of gold-plated copper electrode posts 46 are attached.

[0035] The ends of the electrode posts 46 on the lower side of the end cap are substantially flush with the interface end 54 of the cartridge formed by the end cap 48. These ends become the portion of the electrodes to which the correspondingly aligned spring contacts of the control unit connect when the cartridge is assembled and connected to the control unit. The ends of the electrode posts on the inside of the cartridge extend from the end cap 48 into the holes of the elastic plug 44 through which the contact leads 41 pass. The electrode posts are slightly larger than the holes and include a chamfer at their upper ends to facilitate insertion into the holes of the elastic plug 44, where the electrode posts are maintained in pressurized contact with the contact leads 41 of the heater 40 by the elasticity of the elastic plug.

[0036] The end cap has a base section 124 and an upright wall 120 that matches the inner surface of the housing portion 32. The upright wall 120 of the end cap 48 is inserted into the housing portion 32 so that when the cartridge is assembled, the latch projection 70 engages with the latch recess 68 of the housing portion 32 and the end cap 48 snaps into place in the housing portion. The upper part of the upright wall 120 of the end cap 48 abuts against the peripheral portion of the elastic plug 44, and the lower surface of the spacer 116 of the elastic plug also abuts against the base section 124 of the elastic plug, so that when the end cap 48 is attached to the housing portion, it pressurizes the elastic plug 44 and maintains it in a slightly compressed state.

[0037] The base portion 124 of the end cap 48 includes a peripheral lip that extends beyond the base of the upright wall 112, which has a thickness that matches the thickness of the outer wall portion of the housing at the interface end of the cartridge.

[0038] When the cartridge is assembled, an air channel is formed that extends from the air inlet of the end cap 54 through the cartridge to the steam outlet 60. The first portion of the air channel from the air inlet of the end cap is formed by a central hole that penetrates the elastic plug 44. The second portion of the air channel is formed by the internal region of the inner wall 104 of the elastic plug 44 and the outlet pipe 38 around the heater 40. This second portion of the air channel is also sometimes called the steam generation region and is the main region where steam is generated during use. The air channel from the air inlet at the base of the end cap 54 to the steam generation region is sometimes called the air inlet section of the air channel. The third portion of the air channel is formed by the remainder of the outlet pipe 38. The fourth portion of the air channel is formed by the inner pipe 62 of the outer housing that connects the air channel to the steam outlet 60. The air channel from the steam generation region to the steam outlet is sometimes called the steam outlet section of the air channel.

[0039] When the cartridge is assembled, a liquid reservoir is formed by the space outside the air channel and inside the housing portion 32. This reservoir can be filled during manufacturing, for example, through a filling hole that is later sealed, or by other means. The specific properties of the liquid, for example, its composition, are not of primary importance to the principles described herein, and generally any conventional liquid of the type commonly used in e-cigarettes may be used. The reservoir is closed by an elastic plug 44 at the interface end of the cartridge. The liquid transfer element (capillary wick) 42 of the vaporizer assembly 36 penetrates the opening in the wall of the air channel, which is formed by the elastic plug 44 and the semicircular recesses 110, 90 of the outlet tube 38 and the cradle section 112 of the elastic plug 44, which engage with each other as discussed above. Thus, the end of the liquid transfer element 42 extends into the reservoir, from which the liquid transfer element draws the liquid through the opening in the air channel to the heater 40 for subsequent vaporization.

[0040] During normal use, cartridge 2 is connected to control unit 4, which is activated and power is supplied to the cartridge via the contact electrodes 46 of the end cap 48. The power then reaches heater 40 via connecting lead wires 41. The heater is thus electrically heated, vaporizing a portion of the liquid from the liquid transfer element near the heater. This vaporization generates vapor in the vapor generation region of the air path. The liquid vaporized from the liquid transfer element is followed by additional liquid drawn in from the reservoir by capillary action. While the heater is activated and the user is inhaling from the mouthpiece end 52 of the cartridge, air is drawn into the cartridge through the air inlet of the end cap 54 and through the holes in the base portion 100 of the elastic plug 44 into the vapor generation region surrounding heater 40. The incoming air mixes with the vapor generated by the heater to form a condensed aerosol, which is then drawn in along the outlet tube 38 and the inner portion 62 of the housing before exiting through the mouthpiece outlet / vapor outlet 60 for the user's inhalation. In some exemplary embodiments, the air channel from the air inlet to the vapor outlet may have its smallest cross-sectional area where it passes through the holes in the elastic plug. That is, the holes in the elastic plug may be the primary factor in determining the total resistance to inhaling the e-cigarette.

[0041] As described above, according to certain embodiments of this disclosure, the liquid transfer element 42 may include cotton, for example, Japanese cotton. While cotton is known to be used as wicking material in vapor supply systems, the inventors have found that performance can be improved in some scenarios by novel methods of doing so. For example, a known method for obtaining cotton wicks for e-cigarettes involves cutting strips from a flat sheet of cotton and winding these cotton strips to form a wick element that is inserted along the axis of a pre-made heater coil. However, the inventors have found that improved performance can be achieved in various ways, for example, by forming a wick containing two or more twisted cotton threads, as opposed to a wound cotton strip, and / or by winding heater wire around the wick to form a heater coil that compresses the wick, as opposed to inserting the wick into a pre-made coil, and / or by selecting an appropriate heater coil resistance to complement the cotton wick. The various aspects and features of these novel methods are described further below.

[0042] Figure 4 is a schematic flow diagram illustrating a method for forming a material for use as a liquid transfer element (i.e., wick material) in a vaporizer assembly of a steam supply system according to a particular embodiment of the present disclosure, such as the vaporizer assembly 36 discussed above.

[0043] In step S1, the raw materials for the wick material are supplied. In this example, the raw materials include combed cotton, for example, medical organic cotton, which may be, for example, Japanese cotton. The cotton may have a relatively long fiber length, for example, an average fiber length of about 31 mm. It should be understood that this is just one exemplary specific material and average fiber length for one particular embodiment, and in another example, the raw materials may include a different form of cotton and / or have a different average fiber length, for example, more than about 15 mm, for example more than about 20 mm, for example more than about 25 mm, for example more than about 30 mm.

[0044] In step S2, the raw materials are formed into bundles having a mass of approximately 250 kg. This is merely one exemplary bundle size for one particular embodiment, and it should be understood that in another example, the raw materials can be bundled to a different mass, e.g., a bundle mass exceeding approximately 100 kg, e.g., a bundle mass exceeding approximately 150 kg, e.g., a bundle mass exceeding approximately 200 kg, and / or a bundle mass less than approximately 400 kg, e.g., less than approximately 350 kg, e.g., less than 300 kg. More generally, it should be understood that a particular bundle size can be selected depending on the capacity of the processing line used and the desired amount of wick material.

[0045] In step S3, the bundles of raw materials are refined (degreased and bleached). This is done by placing four bundles of raw materials (i.e., about 1 ton) in a washing container containing water (refining solution), about 0.5% (by weight) of medical-grade NaOH, about 1.8% (by weight) of medical-grade H2O2, and about 3.0% (by weight) of food-grade citric acid monohydrate for about 2.5 hours. It should be understood that these parameters are merely examples for one particular embodiment, and different parameters may be used in other embodiments. For example, in some cases, this refining process can be applied to batches of larger or smaller bundles, taking into consideration, for example, the capacity of the refining container and the amount of wick material desired.

[0046] Furthermore, the time the raw materials are in the smelting solution can vary in other cases. For example, more generally, the time the raw materials are in the smelting solution may exceed about 1 hour, for example, exceed about 1.5 hours, for example, exceed about 2 hours, and / or the time the raw materials are in the smelting solution may be less than about 4 hours, for example, less than about 3.5 hours, for example, less than 3 hours.

[0047] Furthermore, the specific composition of the smelting fluid may differ in other embodiments.

[0048] For example, depending on the circumstances, the smelting solution may contain NaOH in different proportions, for example, more than about 0.1% by weight, for example more than about 0.2%, for example more than about 0.3%, for example more than about 0.4%, and / or less than about 1% by weight, for example less than about 0.9%, for example less than about 0.8%, for example less than about 0.7%, for example less than 0.6%. Furthermore, the smelting solution may contain, instead or in addition, chemically appropriate NaOH substitutes, such as another base / alkali hydroxide.

[0049] Similarly, the smelting fluid may, depending on the circumstances, contain H2O2 in different proportions, for example, more than about 0.5% by weight, for example more than about 0.7%, for example more than about 0.9%, for example more than about 1.1%, for example more than about 1.3%, for example more than about 1.5%, and / or less than about 3% by weight, for example less than about 2.8%, for example less than about 2.6%, for example less than about 2.4%, for example less than about 2.2%, for example less than 2.0%. Furthermore, the smelting fluid may contain, instead of or in addition to, chemically appropriate substitutes such as other oxidizing agents / bleaching agents.

[0050] Furthermore, the smelting fluid may, in some cases, contain citric acid monohydrate in different proportions, for example, more than about 1% by weight, for example more than about 1.5%, for example more than about 2.0%, for example more than about 2.5%, and / or less than about 5% by weight, for example less than about 4.5%, for example less than about 4%, for example less than 3.5%. Furthermore, the smelting fluid may contain, instead of or in addition to, chemically appropriate substitutes.

[0051] In step S4, the bundle of refined raw materials is removed from the refining vessel and left to rest (drain) for approximately 30 minutes. It should be understood that this is merely one exemplary resting period for one particular embodiment, and in another embodiment, the refined bundle may be left for a longer or shorter resting period. For example, more generally, the resting period may be longer than approximately 10 minutes, e.g., longer than approximately 15 minutes, e.g., longer than approximately 20 minutes, e.g., longer than approximately 25 minutes, and / or the resting period may be less than approximately 60 minutes, e.g., less than approximately 50 minutes, e.g., less than approximately 45 minutes, e.g., less than approximately 40 minutes, e.g., less than approximately 35 minutes.

[0052] In step S5, the bundle of refined raw materials is heated to approximately 120 degrees Celsius for approximately 5 minutes for drying. It should be understood that these parameters are merely examples for one particular embodiment, and different parameters may be used in other embodiments. For example, more generally, the drying time in step S5 may be more than approximately 1 minute, e.g., more than approximately 2 minutes, e.g., more than approximately 3 minutes, e.g., more than approximately 4 minutes, and / or the drying time in step S5 may be less than approximately 20 minutes, e.g., less than approximately 15 minutes, e.g., less than approximately 10 minutes, e.g., less than approximately 9 minutes, e.g., less than approximately 8 minutes, e.g., less than approximately 7 minutes, e.g., less than approximately 6 minutes. Furthermore, more generally, the drying temperature in step S5 may exceed approximately 90 degrees Celsius, for example, exceeding approximately 95 degrees Celsius, for example, exceeding approximately 100 degrees Celsius, for example, exceeding approximately 105 degrees Celsius, for example, exceeding approximately 110 degrees Celsius, for example, exceeding approximately 115 degrees Celsius, and / or the drying temperature in step S5 may be less than approximately 150 degrees Celsius, for example, less than approximately 145 degrees Celsius, for example, less than approximately 140 degrees Celsius, for example, less than approximately 135 degrees Celsius, for example, less than approximately 130 degrees Celsius, for example, less than approximately 125 degrees Celsius.

[0053] In step S6, the dry cotton has a linear mass of approximately 0.7 g / m (mass per unit length) and approximately 5 mm 2It is spun into cotton yarn having a cross-sectional area. This can be done using conventional cotton spinning techniques, for example, using a properly configured drawing frame. It should be understood that this is merely one exemplary yarn mass and cross-sectional area for one particular embodiment. In another example, the cotton may be spun to form yarns having different yarn masses and / or different cross-sectional areas. For example, in some cases the yarn may have a yarn mass greater than about 0.3 g / m, such as greater than about 0.4 g / m, such as greater than about 0.5 g / m, such as greater than about 0.6 g / m, and / or a yarn mass less than about 1.2 g / m, such as less than about 1.1 g / m, such as less than about 1.0 g / m, such as less than about 0.9 g / m, such as less than about 0.8 g / m. Further, in some cases the yarn may have a cross-sectional area greater than about 1 mm 2 such as greater than about 2 mm 2 such as greater than about 3 mm 2 such as greater than about 4 mm 2 such as greater than about 9 mm 2 and / or a cross-sectional area less than about 9 mm, such as less than about 8 mm 2 such as less than about 7 mm 2 such as less than about 6 mm 2 such as less than about 6 mm.

[0054] In step S7, two cotton threads are twisted together to form the wick material. In this example, the two threads are twisted relatively loosely, i.e., the twist length is relatively long, for example, about 22 twists per meter (i.e., an average pitch of about 4.5 cm per twist). In another example, the threads may be twisted to form a wick material with a different number of windings / twists per meter. For example, the number of twists per meter may be more than about 10, e.g., more than about 12, e.g., more than about 14, e.g., more than about 16, e.g., more than about 18, e.g., more than about 20, and / or the number of twists per meter may be less than about 34, e.g., less than about 32, e.g., less than about 30, e.g., less than about 28, e.g., less than about 26, e.g., less than about 24. Furthermore, in this example the wick material consists of two twisted cotton threads, but in another example there may be more than two twisted cotton threads, e.g., three twisted cotton threads, four twisted cotton threads, five twisted cotton threads, or even more twisted cotton threads. In any case, step S7 can be carried out using conventional cotton twisting techniques, for example, using a appropriately configured twisting machine. In this example, two cotton yarns are twisted together such that the resulting wick material has a wire mass of approximately 1.4 (±10%) g / m and a characteristic diameter of approximately 3.5 (+1.0 / -0.5) mm.

[0055] It should be understood that wick materials generally do not have a strictly circular cross-section, and in this regard, the characteristic diameter of the wick material can be interpreted as corresponding to the diameter of a circle having the same cross-sectional area as the wick in a plane perpendicular to its length (i.e., characteristic diameter = 2 × the square root of (cross-sectional area / π)). It should also be understood that the characteristic diameter of the wick material is most likely to vary to some extent along the length of the wick material, and in this regard, the characteristic diameter can be considered to be the length-averaged characteristic diameter (for example, the length being averaged is longer than the expected scale of typical diameter variation, e.g., over 2 or 3 centimeters). Therefore, for simplicity, the term diameter may be used in this document, but it should be interpreted as referring to the length-averaged characteristic diameter (both for the wick material and for the yarns that make up the wick material). For example, the diameter corresponding to the diameter of a circle having the same wick material length-averaged cross-sectional area, averaged over a typical length of the wick in a vaporizer assembly containing wick material, is averaged over, for example, about 1 cm, 2 cm, 3 cm, or more. In that sense, the diameter of the cross-section of uncompressed wick material can, at a certain point, be characterized as the diameter of a cylinder having the same length and volume as the uncompressed wick material, and the same is true for the cross-section of compressed wick material.

[0056] It should be understood that the values ​​of wire mass and characteristic diameter of the wick material are examples of one particular embodiment. In another example, cotton yarns can be twisted together to form wick materials having different wire masses and characteristic diameters. For example, the wick material may have a ray mass exceeding approximately 0.5 g / m, for example, exceeding approximately 0.6 g / m, for example, exceeding approximately 0.7 g / m, for example, exceeding approximately 0.8 g / m, for example, exceeding approximately 0.9 g / m, for example, exceeding approximately 1.0 g / m, for example, exceeding approximately 1.1 g / m, for example, exceeding approximately 1.2 g / m, for example, exceeding approximately 1.3 g / m, and / or the wick material may have a ray mass of less than approximately 2.5 g / m, for example, less than approximately 2.4 g / m, for example, less than approximately 2.3 g / m, for example, less than approximately 2.2 g / m, for example, less than approximately 2.1 g / m, for example, less than approximately 2.0 g / m, for example, less than approximately 1.9 g / m, for example, less than approximately 1.8 g / m, for example, less than approximately 1.7 g / m, for example, less than approximately 1.6 g / m, for example, less than approximately 1.5 g / m. Furthermore, in some cases the wick material may have a characteristic diameter greater than approximately 2.7 mm, for example, greater than approximately 2.8 mm, for example, greater than approximately 2.9 mm, for example, greater than approximately 3.0 mm, for example, greater than approximately 3.1 mm, for example, greater than approximately 3.2 mm, for example, greater than approximately 3.3 mm, for example, greater than approximately 3.4 mm, and / or the wick material may have a characteristic diameter less than approximately 4.5 mm, for example, less than approximately 4.4 mm, for example, less than approximately 4.3 mm, for example, less than approximately 4.2 mm, for example, less than approximately 4.1 mm, for example, less than approximately 4.0 mm, for example, less than approximately 3.9 mm, for example, less than approximately 3.8 mm, for example, less than approximately 3.7 mm, for example, less than approximately 3.6 mm. The tolerances of the parameters of the wick material are determined by the embodiment at hand. In this example, it is assumed that the tolerance of the wire mass of the wick material is about ±10%, and the tolerance of the characteristic diameter of the wick material is about +1 mm / -0.5 mm. More generally, the manufacturing method of wick material involves controlling the wick material diameter to fit a target diameter within a tolerance of +5% / -2.5% of the target diameter.

[0057] With respect to the cross-sectional area in a plane perpendicular to the axis of the wick material range (i.e., the plane of the minimum cross-section), the diameter of the wick material in these exemplary ranges corresponds to the wick material, which is 5.7 m. 2 A cross-sectional area exceeding, for example, approximately 6.2 mm² 2 For example, approximately 6.6 mm 2 For example, approximately 7.1 mm 2 For example, approximately 7.5 mm 2 For example, approximately 8.0 mm 2 For example, approximately 8.6 mm 2 For example, approximately 9.1 mm 2 It may have a cross-sectional area exceeding 15.9 mm, and / or the wick material may be 15.9 mm 2 Cross-sectional area less than, for example, about 15.2 mm² 2 Less than, for example, about 14.5 mm 2 Less than, for example, about 13.9 mm 2 Less than, for example, about 13.2 mm 2 Less than, for example, about 12.6 mm 2 Less than, for example, about 11.9 mm 2 Less than, for example, about 11.3 mm 2 Less than, for example, about 10.8 mm 2 Less than, for example, about 10.2 mm 2 It may have a cross-sectional area of ​​less than [a certain value].

[0058] As discussed above with respect to step S7, after the wick material is formed by twisting a pair of cotton threads, in some examples it may be subjected to quality control monitoring / testing, as schematically shown in step S8. There are various different tests that can be employed for quality control purposes, and these tests may be applied to all wick material (e.g., tests related to appearance) or to selected material samples (e.g., destructive testing), in accordance with the established principles of batch testing in the production process. For example, as also shown in step S8, in some examples there may be requirements for one or more of the following: namely, (i) the wick material must be white and free of foreign particles (e.g., for contamination testing), (ii) a sample of wick material, for example 5g, must sink in water within a given time, for example 10 seconds (e.g., for absorbency testing), (iii) the sample must have a breaking tension of approximately 0.3 (±0.1) kgf (e.g., for strength testing), and (iv) the average fiber length must be approximately 31 mm (this can be tested, for example, using a capacitive length tester).

[0059] In step S9, assuming that the current batch of wick material passes the quality control test in step S8, the wick material is formed into rolls for storage and / or further processing. In this example, it is assumed that each roll of wick material contains 1 (±10%) kg of wick material. However, it should be understood that the roll size may differ in other embodiments, for example, considering the scale to which the wick material is processed to form a vaporizer assembly.

[0060] In the exemplary process shown in Figure 4, it is assumed that the wick material is stored before any further processing (i.e., before being incorporated into the vaporizer assembly), and as shown in step S10, according to the method proposed herein, the wick material is stored in a food bag at a humidity of 40% to 70%.

[0061] Thus, Figure 4 schematically illustrates a method for forming wick material for use in an e-cigarette vaporizer assembly according to a particular embodiment of the present disclosure, for example, for use in e-cigarette 1 shown in Figures 1 and 2. It should be understood that the method shown in Figure 4 is merely one specific example, and modifications to this method may be adopted depending on other embodiments of the present disclosure. For example, some of the steps shown in Figure 4 may be omitted in some exemplary embodiments. For example, the quality control testing step along the line shown as step S8 in Figure 4 may not be performed in some examples. Furthermore, as already noted above, the specific exemplary parameters shown in Figure 4 represent values ​​suitable for one embodiment presented as a specific example, and it should be understood that different specific values ​​may be used in other embodiments. It should be understood that the various steps of the method shown above in relation to Figure 4 can be formed manually or automatically using a appropriately configured machine.

[0062] Figure 5 is a schematic flowchart illustrating a method for forming a vaporizer assembly of a steam supply system according to a particular embodiment of this disclosure, such as the vaporizer assembly 36 discussed above, using materials manufactured according to the principle shown in Figure 4. However, it should be understood that in another example, the principle shown in Figure 5 may be applied to form a vaporizer using a liquid transfer element that is not manufactured according to the principle shown in Figure 4.

[0063] The process begins in step T1 using a roll of wick material obtained by the process shown in Figure 4 (the wick material has been removed from any storage bag / container).

[0064] In step T2, the roll of wick material is subjected to quality control testing. There are various different tests that can be employed for quality control purposes, some of which may correspond to the quality control testing methods discussed above with reference to step S8 in Figure 4. The tests may be applied to the roll of wick material as a whole (e.g., tests related to appearance) or to a sample of the material (e.g., destructive testing), according to the established principles of product batch testing. For example, as also shown in step S8, in some cases there may be requirements for one or more of the following: Specifically, (i) the wick material must be white and free of foreign particles (e.g., for contamination testing), (ii) a roll of wick material must have a mass of 1 (±10%) kg, (iii) a sample of wick material, for example, 5 g, must sink in water within a given time, for example, within 10 seconds (e.g., for absorbency testing), (iv) the sample must have a breaking tension of approximately 0.3 (±0.1) kgf (e.g., for strength testing), (v) the average fiber length must be approximately 31 mm (this can be tested, for example, using a capacitive length tester), and (vi) the diameter of the wick material must be approximately 3.5 (+1.0 / -0.5) mm. It will be understood that these specific quality control parameters are based on these desired properties of the wick material, as discussed above in relation to the manufacturing process in Figure 4. In another exemplary embodiment, the wick material may have different target values ​​for these parameters, as discussed above, in which case the quality control tests will be modified accordingly.

[0065] In step T3, a section of heater wire is wound around the wick material to form a heater coil. As described above, in this example, the heater wire includes a nickel-chromium (nichrome) alloy, for example, an 80:20 Ni:Cr alloy. However, it should be understood that in other examples, different materials may be used, for example, a different type of electrical resistance wire previously used in e-cigarettes. In other examples, the heater may not have a coil, but may have, for example, a tubular collar having a similar overall size to the coil in this example.

[0066] In this example, the wire is formed into a coil around a wick material, having a diameter of approximately 0.188 (±0.020) mm, an outer diameter of approximately 2.5 (±0.2) mm, and an average pitch of approximately 0.60 (±0.2) mm. The coil in this example has a full 8 turns (i.e., a total of 8.5 turns of wire around the wick material), and the total length of the coil around the wick material is approximately 5.0 (±0.5) mm. The total length of the wire forming the coil is approximately 70 (±2.5) mm. The wire constituting the coil in this example has an electrical resistance of 1.4 (±0.1) ohms. In the examples discussed in this book, the resistance of the heater coil should be interpreted as the resistance measured when the coil is cold (i.e., not when heated and producing steam, when its resistance is slightly higher than when it is cold). It should be understood that these various characteristics of a coil example of one particular embodiment, and that different values ​​of these characteristics may be adopted in other examples, are important considerations.

[0067] In some cases, the diameter of the heating element may exceed approximately 0.15 mm, for example, exceeding approximately 0.16 mm, for example, exceeding approximately 0.17 mm, for example, exceeding approximately 0.18 mm, and / or the diameter of the heating element may be less than approximately 0.23 mm, for example, less than approximately 0.22 mm, for example, less than approximately 0.21 mm, for example, less than approximately 0.19 mm.

[0068] Depending on the circumstances, the coil formed from the heating wire may have an outer diameter greater than approximately 2.0 mm, for example greater than approximately 2.1 mm, for example greater than approximately 2.2 mm, for example greater than approximately 2.3 mm, for example greater than approximately 2.4 mm, and / or the coil formed from the heating wire may have an outer diameter of less than approximately 3.0 mm, for example less than approximately 2.9 mm, for example less than approximately 2.8 mm, for example less than approximately 2.7 mm, for example less than approximately 2.6 mm.

[0069] With respect to the inner diameter of the coil (which matches the outer diameter of the portion of the wick compressed by the heating element), in some cases the coil formed from the heating wire may have an inner diameter greater than approximately 1.6 mm, e.g., greater than approximately 1.7 mm, e.g., greater than approximately 1.8 mm, e.g., greater than approximately 1.9 mm, e.g., greater than approximately 2.0 mm, and / or the coil formed from the heating wire may have an inner diameter less than approximately 2.6 mm, e.g., less than approximately 2.5 mm, e.g., less than approximately 2.4 mm, e.g., less than approximately 2.3 mm, e.g., less than approximately 2.1 mm.

[0070] In some cases, the coil formed from the heating wire may have a pitch greater than approximately 0.4 mm, for example greater than approximately 0.45 mm, for example greater than approximately 0.5 mm, for example greater than approximately 0.55 mm, and / or the coil formed from the heating wire may have a pitch less than approximately 0.85 mm, for example less than approximately 0.8 mm, for example less than approximately 0.75 mm, for example less than approximately 0.7 mm, for example less than approximately 0.65 mm.

[0071] In some cases, the coil may include wires with more than five full turns around the wick material, for example, wires with more than six full turns around the wick material, or for example, wires with more than seven full turns around the wick material, and / or wires with fewer than ten full turns around the wick material, for example, wires with fewer than eleven full turns around the wick material, or for example, wires with fewer than twelve full turns around the wick material. In some examples, the coil may include wires with eight or nine full turns around the wick material.

[0072] In some cases, the coil formed from the heating wire may stretch along the wick material by more than approximately 3 mm, for example, more than approximately 3.5 mm, for example, more than approximately 4 mm, for example, more than approximately 4.5 mm, and / or the coil formed from the heating wire may stretch along the wick material by less than approximately 8 mm, for example, less than approximately 7.5 mm, for example, less than approximately 7 mm, for example, less than approximately 6 mm, for example, less than approximately 5.5 mm.

[0073] In some examples, a coil including a heating element may have an electrical resistance greater than approximately 1.3 ohms, e.g., greater than approximately 1.32 ohms, e.g., greater than approximately 1.34 ohms, e.g., greater than approximately 1.36 ohms, e.g., greater than approximately 1.38 ohms, and / or the heating element constituting the coil may have an electrical resistance less than approximately 1.5 ohms, e.g., less than approximately 1.48 ohms, e.g., less than approximately 1.46 ohms, e.g., less than approximately 1.44 ohms, e.g., less than approximately 1.42 ohms. In this regard, it should be understood that, in practice, the exemplary resistances discussed in this book can be measured directly between the ends of the resistance wire itself, or between points on the connecting lead wires that connect the heater coil to its power supply. This is because the additional resistance of the connecting lead wires themselves is negligible compared to the resistance of the heater coil. For example, one convenient way to measure the heater resistance of an assembled steam supply system of the type shown in Figures 1 and 2 is to measure the resistance between the electrical connectors 46 that form the electrical interface of the cartridge section, whereas during assembly, the resistance can be measured, for example, between points on each connecting lead wire 41. It should be understood that since coil resistance is determined by the wire material and geometric shape (i.e., length and thickness), it should not be necessary to measure the resistance of individual vaporizer assemblies to establish their resistance. That is, if the specific coil material and geometry required to obtain the desired resistance are known, then a coil made to this design can be considered to have the desired resistance, and there is no need to actually measure the resistance.

[0074] For the example parameters shown above, it should be understood that the wick material is compressed by the heater wire wound around the wick to form a coil. In particular, in this example, the diameter of the wick material in the coil is compressed from its initially manufactured diameter of approximately 3.5 mm (static diameter) to a diameter of approximately 2.1 mm (because the coil is formed of wire with an outer diameter of approximately 2.5 mm and a thickness of slightly less than 0.2 mm). In other words, in this example, the diameter of the wick material is compressed by the coil to approximately 60% of its static diameter. That is, the diameter of the wick material is compressed by approximately 40% by the coil wound around the wick material. This compression reduces the cross-sectional area of ​​the wick in the coil to approximately 64% (i.e., approximately 9.6 mm before compression). 2 Approximately 3.5 mm after compression by the coil 2 This corresponds to a reduction. The inventors have shown that this type of wick compression by a coil can result in a vaporizer assembly with improved overall performance compared to existing methods, for example, with respect to the amount of vapor produced and the reduction of the possibility of undesirable flavor due to overheating. It should be understood that different amounts of compression may be employed in other exemplary embodiments. For example, the diameter of the wick material may be compressed by the heating coil by only about 20%, e.g., more than about 25%, e.g., more than about 30%, e.g., more than 35%, and / or the diameter of the wick material may be compressed by the heating coil by only about 60%, e.g., less than about 55%, e.g., less than 50%, e.g., less than 45%.

[0075] As described above, the characteristic diameter of a liquid transfer element having a non-circular cross-section may be defined based on the diameter of a circle having the same area as the cross-sectional area of ​​the liquid transfer element. In this regard, the amount by which the wick material is compressed by the heater may be defined based on the reduction in the cross-sectional area of ​​the wick material (in a plane perpendicular to its longest axis) caused by the heater coil. That is, in some examples, the cross-section of the wick material may be compressed by the coil by about 65% (for example, from a diameter of about 3.5 mm to a diameter of about 2.1 mm, as in the specific example discussed above). More generally, according to some embodiments, the cross-sectional area of ​​the wick material may be compressed by the heating coil by more than about 25%, e.g., more than about 30%, e.g., more than 35%, e.g., more than 40%, e.g., more than 45%, e.g., more than 50%, e.g., more than 55%, e.g., more than 60%, and / or the cross-sectional area of ​​the wick material may be compressed by the heating coil by less than about 90%, e.g., less than 85%, e.g., less than 80%, e.g., less than 75%, e.g., less than 70%. In this document, X% compression of the wick material area should be understood as indicating that the cross-sectional area of ​​the wick material after compression is X% of the cross-sectional area of ​​the wick material before compression / uncompressed.

[0076] In step T4, a section of wick material having a length of approximately 20 (±2) mm and placed in the center of the coil is cut from the wick material, for example, using a mechanical cutter. This cut length of the wick material yields the liquid transfer element (wick) of the vapor supply system according to a particular embodiment of the present disclosure. In this regard, the specific length of the wick material cut in step T4 can be selected considering the desired length of the liquid transfer element of the e-cigarette configuration at hand. That is, in this example a length of approximately 20 mm is cut from the wick material, while in another example the wick material may be cut to a different length. For example, the cut length of the wick material may be greater than approximately 10 mm, e.g., greater than approximately 12 mm, e.g., greater than approximately 14 mm, e.g., greater than approximately 16 mm, e.g., greater than approximately 18 mm, and / or the cut length of the wick material may be less than approximately 30 mm, e.g., less than approximately 28 mm, e.g., less than approximately 26 mm, e.g., less than approximately 24 mm, e.g., less than approximately 22 mm.

[0077] In step T5, connecting leads are soldered to each end of the wires that make up the coil. In this example, each connecting lead includes an N6 nickel wire with a diameter of approximately 0.25 (±0.2) mm and a length of approximately 30 (±2) mm. These connecting leads are soldered to the coil by conventional soldering techniques to obtain a solder joint tension of, for example, more than 0.8 kgf. In other examples, it should be understood that different connection means may be employed, such as some soldering, e.g., welding or mechanical clamping. Furthermore, in other examples, it should be understood that the choice of wire material, length, and diameter may vary.

[0078] In some embodiments, the diameter of the connecting lead wire may be greater than approximately 0.15 mm, for example, greater than 0.17 mm, for example, greater than 0.19 mm, for example, greater than 0.21 mm, for example, greater than 0.23 mm, and / or the diameter of the connecting lead wire may be less than approximately 0.35 mm, for example, less than approximately 0.31 mm, for example, less than approximately 0.29 mm, for example, less than approximately 0.27 mm.

[0079] In some embodiments, the length of the connecting lead wire may exceed approximately 15 mm, for example, exceed 20 mm, for example, exceed 25 mm, and / or the length of the connecting lead wire may be less than approximately 50 mm, for example, less than approximately 45 mm, for example less than approximately 40 mm, for example less than approximately 35 mm.

[0080] Thus, Figure 5 schematically illustrates a method for forming a vaporizer assembly for use in an e-cigarette according to a particular embodiment of the present disclosure, for example, for use in e-cigarette 1 shown in Figures 1 and 2. It should be understood that the method shown in Figure 5 is merely one specific example, and modifications to this method may be adopted depending on other embodiments of the present disclosure. For example, some of the steps shown in Figure 5 may be omitted or performed in a different order in some exemplary embodiments. For example, the quality control testing step along the line shown as step T2 in Figure 5 may not be performed in some examples. Furthermore, the wick material may be cut to a certain length (step T4) before the coil is wound around the wick material (step T3), the connecting lead wires may be soldered to the coil (step T5) before the wick material is cut to a certain length (step T4), and / or the coil is wound around the wick material (step T6). Furthermore, as already noted above, the specific exemplary parameters shown in Figure 5 represent values ​​suitable for one embodiment presented as a concrete example, and it should be understood that different specific values ​​may be used in other embodiments. It should also be understood that the various steps of the method shown above in relation to Figure 5 can be formed manually or automatically using a appropriately configured machine.

[0081] Figure 6 shows a side view (not to scale) of the vaporizer assembly 36 of the e-cigarette shown in Figures 1 and 2, manufactured according to the principle shown in Figure 5.

[0082] Figure 7 is a graph illustrating the amount of steam generated by a steam supply system having the overall configuration shown in Figures 1 and 2, but for separate vaporizer assemblies with different combinations of wick material and heater coil resistance. The amount of steam generated by the steam supply system is characterized by the mass loss (ML) per puff (one suction) in milligrams. This characteristic is consistent with the measured mass loss of the steam supply system, which is obtained from a machine with fixed characteristics (e.g., with respect to suction force and duration) and a fixed voltage applied to the heater coil. From the standpoint of user satisfaction, a mass loss of 8 mg per puff is considered a suitable target.

[0083] Figure 7 shows the results for two types of wick materials: silica glass fiber wicks (data points clustered around the solid approximation line) and cotton wicks of the type discussed above, manufactured according to the principles shown in Figures 4 and 5 (data points clustered around the dashed approximation line). Aside from differences in composition, these different wicks are identical in their geometry. The results for each wick material are shown for different heater coil resistances. In particular, Figure 7 shows the results for eight different combinations of wick material and coil resistance: coil resistances of 1.2 ohms, 1.3 ohms, 1.4 ohms, and 1.6 ohms for silica wicks, and coil resistances of 1.2 ohms, 1.4 ohms, 1.6 ohms, and 1.8 ohms for cotton wicks. Multiple measurements of mass loss per puff, measured for each combination of wick material and resistance, are shown in Figure 7. Since the same voltage is applied to each heater coil, resulting in different measurements, higher coil resistance means less power (and therefore less energy) is associated with each puff. This is evident from the fact that both types of wicks exhibit a roughly linear relationship between coil resistance and mass loss, with a generally downward trend in mass loss for increasing resistance.

[0084] Figure 7 shows that using a cotton wick results in consistently higher mass loss per puff for the different resistances shown in Figure 7, compared to using a silica wick. In particular, this result shows that using a cotton wick delivers approximately 2 mg more vapor per puff (i.e., the device loses approximately 2 mg more per puff) compared to using an equivalent silica wick. This indicates that cotton is a more efficient wicking material than silica. For example, to achieve a target mass loss of 8 mg per puff, a coil resistance of approximately 1.4 ohms can be used with a cotton wick, while a coil resistance of approximately 1.2 ohms is required with a silica wick. This suggests that using a cotton wick and a coil resistance of approximately 1.4 ohms can help achieve the desired target mass loss per puff with less power / energy than would be required for the corresponding operation using a silica wick (because using a silica wick requires a low-resistance heater coil with a larger current draw).

[0085] The following table (Table 1) shows the average mass loss (standardized per puff in milligrams) and coil resistance for different wick material combinations shown in Figure 7. For the silica wick and 1.6 ohm heater combination, two values ​​are presented in the table, corresponding to two different configurations of the steam supply system used with this combination. [Table 1]

[0086] In other words, the combination of a cotton wick and a 1.4-ohm heater coil resistor allows for the desired operation of vapor generation (as in the specific exemplary embodiments discussed above with respect to Figures 5 and 6) to be achieved with less power consumption than silica wick-based methods. The resistor does not need to be exactly 1.4 ohms in any particular embodiment, and different heater resistors may be used in other embodiments. It should be understood that, in cases where there is a demand for slightly higher or lower operation in terms of mass loss per puff, all coil resistors in the range of 1.3 to 1.5 ohms, for example, will provide acceptable performance when used with a cotton wick.

[0087] Another important operating characteristic of a vapor supply system is how far the raw liquid material is heated to an undesirable temperature that can produce a burning taste. One way to characterize this is to measure the amount of carbonyl from the e-cigarette, for example, by measuring the amount of formaldehyde produced during use.

[0088] The following table (Table 2) shows the average formaldehyde emissions (per day in micrograms) for several examples (usually five or six) of different combinations of wick materials discussed above. For the combination of silica wick and 1.6 ohm heater, two values ​​are presented in the table, corresponding to two different configurations of the steam supply system. [Table 2]

[0089] This table shows that using cotton wicks results in lower associated formaldehyde emissions across the entire range of coil resistances considered here, compared to using silica wicks.

[0090] Another operating characteristic of e-cigarettes is the potential for leakage during storage and use. Tests of different combinations of wick material and heater coil resistance discussed above, used in the vapor supply system configurations shown in Figures 1 and 2, showed that none of these combinations suffered measurable leakage during storage, normal use, or light tapping. However, all silica wick combinations were found to suffer some degree of leakage during transport; for example, about 2% of the silica wick samples suffered noticeable leakage during transport. The operation of the cotton wick combinations was mostly good, with only about 0.3% of the cotton wick samples suffering noticeable leakage during transport. This appears to indicate that the cotton wick material is superior to the silica wick material in forming a seal where the wick passes through the air channel wall.

[0091] Therefore, considering the operating characteristics observed with different combinations of wick material and coil resistance, it is clear that using a cotton wick with a coil resistance in the range of 1.3 to 1.5 ohms is, in some respects, the optimal combination of wick material and heater resistance for use in e-cigarettes (e.g., the types of e-cigarettes shown in Figures 1 and 2).

[0092] While the above description has focused on several different embodiments of liquid transfer elements and / or heaters having several different characteristics, it should be understood that components according to other embodiments of this disclosure may have only some of these characteristics, separate from some of the others. For example, in some embodiments, a wick made according to the principle discussed herein with respect to Figure 5 may be implemented in a vaporizer assembly that does not include a coil wound around the wick to compress the wick, as shown in Figure 6. Similarly, in a vaporizer assembly comprising a cotton wick and a heater coil having a resistance selected according to the principle discussed herein, the wick does not necessarily have to be made according to the method discussed above with respect to Figure 4, Figure 5, or Figure 6, or have a shape thereof. Furthermore, in a vaporizer assembly comprising a heating coil wound around the wick to compress the wick according to the principle discussed herein, as shown in Figure 6, for example, the wick may not necessarily comprise a cotton wick manufactured as disclosed herein in relation to Figure 4, but may comprise a cotton wick manufactured using a different process and / or a different material, such as a different fibrous material such as glass fiber.

[0093] Thus, a method for producing wick material for use as a liquid transfer element in a steam supply system has been described, which includes providing at least two cotton threads and twisting these cotton threads together to form a wick material such that the wick material consists of two or more cotton threads.

[0094] A vaporizer assembly for use in a steam supply system is also described, comprising a liquid transfer element having a heater-wrapped portion and a non-heater-wrapped portion, and a heating element wrapped around the heater-wrapped portion, wherein the heater-wrapped portion of the liquid transfer element is compressed by the heating element, so that its cross-sectional area is reduced by more than 25% compared to the non-heater-wrapped portion.

[0095] A vaporizer assembly for use in a steam supply system is also described, comprising a liquid transfer element formed from cotton and a heating coil positioned around a portion of the liquid transfer element, the heating coil having an electrical resistance between 1.3 and 1.5 ohms.

[0096] While the embodiments described above focus in some respects on certain specific exemplary steam supply systems, it should be understood that the same principles can be applied to steam supply systems using other technologies. That is, the specific ways in which various embodiments of steam supply systems function, for example, how the system is started for use and the functionality achieved by the system, are not directly related to the fundamental principles of the examples described herein.

[0097] To address various issues and advance technology, this disclosure illustrates various embodiments that can put the claimed(one or more) invention into practice. The advantages and features of this disclosure are merely representative examples of the embodiments and are not exhaustive and / or exclusive. These advantages and features are presented solely to help and teach the claimed(one or more) invention. It should be understood that the advantages, embodiments, examples, functions, features, structures, and / or other aspects of this disclosure should not be construed as limitations to the disclosure as defined by the claims, or to equivalents of the claims, and that other embodiments may be utilized and modified without departing from the claims. Various embodiments may appropriately include, consist of, or essentially consist of various combinations of disclosed elements, components, features, members, steps, means, etc., other than those specifically described herein, and therefore, it should be understood that dependent features may be combined with independent features other than those expressly stated in the claims. This disclosure may include other inventions that are not currently claimed but may be claimed in the future. [Explanation of Symbols]

[0098] 36...Vaporizer assembly, 40...Heater coil, 41...Heater lead wire, 42...Liquid transfer element, 43...Solder joint.

Claims

1. A liquid transport element made from cotton, A heating element including a coil made of resistance wires around a portion of the liquid transfer element A vaporizer assembly for use in a steam supply system, comprising: The heating element has an electrical resistance between 1.3 and 1.5 ohms. A vaporizer assembly in which a portion of the liquid transfer element within the coil is compressed by the coil, so that its cross-sectional area is reduced by more than 25% compared to an incompressible liquid transfer element.

2. The vaporizer assembly according to claim 1, wherein the heating element has an electrical resistance selected from the group consisting of greater than 1.32 ohms, greater than 1.34 ohms, greater than 1.36 ohms, and greater than 1.38 ohms, and the heating element has an electrical resistance selected from the group consisting of less than 1.5 ohms, less than 1.48 ohms, less than 1.46 ohms, less than 1.44 ohms, and less than 1.42 ohms.

3. The vaporizer assembly according to claim 1 or 2, wherein the coil has an outer diameter selected from the group consisting of greater than 2.0 mm, greater than 2.1 mm, greater than 2.2 mm, greater than 2.3 mm, and greater than 2.4 mm, and the coil has an outer diameter selected from the group consisting of less than 3.0 mm, less than 2.9 mm, less than 2.8 mm, less than 2.7 mm, and less than 2.6 mm.

4. The vaporizer assembly according to any one of claims 1 to 3, wherein the heating element extends along the liquid transfer element by a distance selected from the group consisting of more than 3 mm, more than 3.5 mm, more than 4 mm, and more than 4.5 mm, and the heating element extends along the liquid transfer element by a distance selected from the group consisting of less than 8 mm, less than 7.5 mm, less than 7 mm, less than 6.5 mm, less than 6 mm, and less than 5.5 mm.

5. The vaporizer assembly according to any one of claims 1 to 4, wherein the liquid transfer element has a length selected from the group consisting of more than 10 mm, more than 12 mm, more than 14 mm, more than 16 mm, and more than 18 mm, and the liquid transfer element has a length selected from the group consisting of less than 30 mm, less than 28 mm, less than 26 mm, less than 24 mm, and less than 22 mm.

6. The vaporizer assembly according to any one of claims 1 to 5, wherein the resistance wire constituting the coil has a diameter selected from the group consisting of greater than 0.15 mm, greater than 0.16 mm, greater than 0.17 mm, and greater than 0.18 mm, and the resistance wire constituting the coil has a diameter selected from the group consisting of less than 0.23 mm, less than 0.22 mm, less than 0.21 mm, and less than 0.19 mm.

7. The vaporizer assembly according to any one of claims 1 to 6, wherein the coil includes 6 to 12 complete turns around the liquid transfer element.

8. The vaporizer assembly according to any one of claims 1 to 7, wherein the coil has a pitch selected from the group consisting of greater than 0.45 mm, greater than 0.5 mm, and greater than 0.55 mm, and / or the coil has a pitch selected from the group consisting of less than 0.85 mm, less than 0.8 mm, less than 0.75 mm, less than 0.7 mm, and less than 0.65 mm.

9. The vaporizer assembly according to any one of claims 1 to 8, further comprising a first connecting lead wire and a second connecting lead wire electrically connected to the coil.

10. The vaporizer assembly according to any one of claims 1 to 9, wherein the liquid transfer element includes cotton yarn.

11. The vaporizer assembly according to claim 10, wherein the liquid transfer element includes two or more twisted cotton threads.

12. The vaporizer assembly according to any one of claims 1 to 11, wherein the liquid transfer element has an incompressible diameter selected from the group consisting of greater than 2.7 mm, greater than 2.8 mm, greater than 2.9 mm, greater than 3.0 mm, greater than 3.1 mm, greater than 3.2 mm, greater than 3.3 mm, and greater than 3.4 mm, and the liquid transfer element has an incompressible diameter selected from the group consisting of less than 4.5 mm, less than 4.4 mm, less than 4.3 mm, less than 4.2 mm, less than 4.1 mm, less than 4.0 mm, less than 3.9 mm, less than 3.8 mm, less than 3.7 mm, and less than 3.6 mm.

13. The vaporizer assembly according to any one of claims 1 to 12, wherein the liquid transfer element has a linear mass selected from the group consisting of greater than 0.5 g / m, greater than 0.6 g / m, greater than 0.7 g / m, greater than 0.8 g / m, greater than 0.9 g / m, greater than 1.0 g / m, greater than 1.1 g / m, greater than 1.2 g / m, and greater than 1.3 g / m, and the liquid transfer element has a linear mass selected from the group consisting of less than 2.5 g / m, less than 2.4 g / m, less than 2.3 g / m, less than 2.2 g / m, less than 2.1 g / m, less than 2.0 g / m, less than 1.9 g / m, less than 1.8 g / m, less than 1.7 g / m, less than 1.6 g / m, and less than 1.5 g / m.

14. An apparatus comprising a vaporizer assembly according to any one of claims 1 to 13 and a reservoir for a raw material liquid, wherein the liquid transfer element is arranged to draw the raw material liquid from the reservoir to a heating element for heating to generate vapor for inhalation by the user.

15. The apparatus according to claim 14, wherein the apparatus is a cartridge for use in a steam supply system.

16. The apparatus according to claim 14, wherein the apparatus is a steam supply system, further comprising a controller and a battery, wherein the controller is configured to selectively control the supply of power from the battery to the vaporizer assembly.

17. A liquid transfer means made from cotton, A heating element including a coil made of resistance wires surrounding a portion of the liquid transfer means A vaporizer assembly means for use in a steam supply means, comprising: A vaporizer assembly means wherein the heating element has an electrical resistance between 1.3 and 1.5 ohms, and a portion of the liquid transfer means within the coil is compressed by the coil, so that its cross-sectional area is reduced by more than 25% compared to an incompressible liquid transfer means.

18. A step of supplying a liquid transfer element made from cotton, The step of forming a heating element which includes a coil made of resistance wires surrounding a portion of the liquid transfer element. A method for manufacturing a vaporizer assembly for use in a steam supply system, including, A method for manufacturing a vaporizer assembly, wherein the heating element has an electrical resistance between 1.3 and 1.5 ohms, and the portion of the liquid transfer element within the coil is compressed by the coil so that its cross-sectional area is reduced by more than 25% compared to an incompressible liquid transfer element.

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