Patent Publication Number: US-2018042301-A1

Title: Vaporizer of an electronic vaping device and method of forming a vaporizer

Description:
BACKGROUND 
     Field 
     The present disclosure relates to an electronic vaping or e-vaping device. 
     Description of Related Art 
     An e-vaping device includes a heater element which vaporizes a pre-vapor formulation to produce a “vapor.” 
     The e-vaping device includes a power supply, such as a rechargeable battery, arranged in the device. The battery is electrically connected to the heater, such that the heater heats to a temperature sufficient to convert a pre-vapor formulation to a vapor. The vapor exits the e-vaping device through a mouthpiece including at least one outlet. 
     SUMMARY 
     At least one example embodiment relates to a method of forming a vaporizer of an electronic vaping device. 
     In at least one example embodiment, a method of forming a vaporizer of an electronic vaping device includes applying a porous material to at least one surface of a heating element to form a coating thereon, the heating element formed of a conductive material. 
     In at least one example embodiment, the porous material has a porosity ranging from about 50% to about 80%. The porous material is flexible when dry. The porous material is a hydrophilic material. The porous material includes at least one of ceramic and cellulose. 
     In at least one example embodiment, the coating has a thickness ranging from about 0.5 mm to about 1.0 mm. 
     In at least one example embodiment, the applying step includes dipping the heating element in a slurry including the porous material. In at least one example embodiment, the method includes drying the heating element at a temperature of about 100° F. to about 500° F. The slurry comprises about 50% to about 99% of the porous material. 
     In at least one example embodiment, the applying step includes spraying the heating element with a composition including the porous material. The method may include drying the heating element. 
     In at least one example embodiment, the applying step includes adhering the porous material to at least one surface of the heating element. 
     In at least one example embodiment, the method includes shaping the heating element before the applying step. 
     In at least one example embodiment, the method includes shaping the heating element after the applying step. 
     At least one example embodiment relates to a cartridge of an electronic vaping device. 
     In at least one example embodiment, a cartridge of an electronic vaping device includes a housing extending in a longitudinal direction, a reservoir in the housing, the reservoir configured to store a pre-vapor formulation, a vaporizer in the housing, and an absorbent material between the reservoir and vaporizer. The vaporizer includes a heating element formed of a conductive material and a coating of a porous material on at least one surface of the heater heating element. The absorbent material is configured to convey the pre-vapor formulation from the reservoir to the coating of the vaporizer. 
     In at least on example embodiment, the porous material has a porosity ranging from about 50% to about 80%. The porous material is flexible when dry. The porous material is a hydrophilic material and includes at least one of ceramic and cellulose. 
     In at least on example embodiment, the heating element is in the form of one or more of a coil, a wire, a plate, a stamped plate, a spiral, a tube, a curled heater, a bar, and a disc. 
     In at least one example embodiment, the coating has a thickness ranging from about 0.5 mm to about 1.0 mm. 
     At least one example embodiment relates to an electronic vaping device. 
     In at least one example embodiment, an electronic vaping device includes a housing extending in a longitudinal direction, a reservoir in the housing, the reservoir configured to store a pre-vapor formulation, a vaporizer in the housing, an absorbent material between the reservoir and the vaporizer, and a power supply in the housing, the power supply electrically connectable to the heating element. The vaporizer includes a heating element formed of a conductive material and a coating of a porous material on at least one surface of the heating element. The absorbent material is configured to convey the pre-vapor formulation from the reservoir to the coating of the vaporizer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The various features and advantages of the non-limiting embodiments herein may become more apparent upon review of the detailed description in conjunction with the accompanying drawings. The accompanying drawings are merely provided for illustrative purposes and should not be interpreted to limit the scope of the claims. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. For purposes of clarity, various dimensions of the drawings may have been exaggerated. 
         FIG. 1  is a side view of an e-vaping device according to at least one example embodiment. 
         FIG. 2  is a cross-sectional view along line II-II of the e-vaping device of  FIG. 1  according to at least one example embodiment. 
         FIG. 3  is an enlarged cross-sectional view of a vaporizer of the e-vaping device of  FIG. 2  according to at least one example embodiment. 
         FIG. 4  is an illustration of a vaporizer according to at least one example embodiment. 
         FIG. 5  is an illustration of a vaporizer and an absorbent material according to at least one example embodiment. 
         FIG. 6  is an illustration of a vaporizer and an absorbent material according to at least one example embodiment. 
         FIG. 7  is an illustration of a vaporizer and an absorbent material according to at least one example embodiment. 
         FIG. 8  is an illustration of a vaporizer and an absorbent material according to at least on example embodiment. 
         FIG. 9  is a diagram of a method of forming a vaporizer according to at least one example embodiment. 
         FIG. 10  is a diagram of a method of forming a vaporizer according to at least one example embodiment. 
         FIG. 11  is a diagram of a method of forming a vaporizer according to at least one example embodiment. 
         FIG. 12  is a diagram of a method of forming a vaporizer according to at least one example embodiment. 
         FIG. 13  is a diagram of a method of forming a vaporizer according to at least one example embodiment. 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Some detailed example embodiments are disclosed herein. However, specific structural and functional details disclosed herein are merely representative for purposes of describing example embodiments. Example embodiments may, however, be embodied in many alternate forms and should not be construed as limited to only the example embodiments set forth herein. 
     Accordingly, while example embodiments are capable of various modifications and alternative forms, example embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit example embodiments to the particular forms disclosed, but to the contrary, example embodiments are to cover all modifications, equivalents, and alternatives falling within the scope of example embodiments. Like numbers refer to like elements throughout the description of the figures. 
     It should be understood that when an element or layer is referred to as being “on,” “connected to,” “coupled to,” or “covering” another element or layer, it may be directly on, connected to, coupled to, or covering the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element or layer, there are no intervening elements or layers present. Like numbers refer to like elements throughout the specification. As used herein, the term “and/of” includes any and all combinations of one or more of the associated listed items. 
     It should be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or section from another region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of example embodiments. 
     Spatially relative terms (e.g., “beneath,” “below,” “lower,” “above,” “upper,” and the like) may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It should be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” may encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     The terminology used herein is for the purpose of describing various example embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes,” “including,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Example embodiments are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of example embodiments. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, example embodiments should riot be construed as limited to the shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, including those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
       FIG. 1  is a side view of an e-vaping device according to at least one example embodiment. 
     In at least one example embodiment, as shown in  FIG. 1 , an electronic vaping device (e-vaping device)  10  may include a replaceable cartridge (or first section)  15  and a reusable battery section (or second section)  20 , which may be coupled together at a threaded connector  25 . It should be appreciated that the connector  25  may be any type of connector, such as a snug-fit, detent, clamp, bayonet, and/or clasp. An air inlet  55  extends through a portion of the connector  25 . 
     In at least one example embodiment, the connector  25  may be the connector described in U.S. application Ser. No. 15/154,439, filed May 13, 2016, the entire contents of which is incorporated herein by reference thereto. As described in U.S. application Ser. No. 15/154,439, the connector  25  may be formed by a deep drawn process. 
     In at least one example embodiment, the first section  15  may include a first housing  30  and the second section  20  may include a second housing  30 ′. The e-vaping device  10  includes a mouth-end insert  35  at a first end. 
     In at least one example embodiment, the first housing  30  and the second housing  30 ′ may have a generally cylindrical cross-section. In other example embodiments, the housings  30  and  30 ′ may have a generally triangular cross-section along one or more of the first section  15  and the second section  20 . Furthermore, the housings  30  and  30 ′ may have the same or different cross-section shape, or the same or different size. As discussed herein, the housings  30 ,  30 ′ may also be referred to as outer or main housings. 
     In at least one example embodiment, the e-vaping device  10  may include an end cap  40  at a second end  50  of the e-vaping device  10 . The e-vaping device  10  also includes a light  60  between the end cap  40  and the first end  45  of the e-vaping device  10 . 
       FIG. 2  is a cross-sectional view along line II-II of the e-vaping device of  FIG. 1   
     In at least one example embodiment, as shown in  FIG. 2 , the first section  15  may include a reservoir  95  configured to store a pre-vapor formulation and a vaporizer  80  that may vaporize the pre-vapor formulation. The vaporizer  80  incudes a heating element  85  and at least one coating of a porous material  90  on at least one surface of the heating element  85 . The porous material  90  may draw the pre-vapor formulation from the reservoir  95 . The e-vaping device  10  may include the features set forth in U.S. Patent Application Publication No. 2013/0192623 to Tucker et al. filed Jan. 31, 2013 and/or features set forth in U.S. patent application Ser. No. 15/135,930 to Holtz et al. filed Apr. 22, 2016, the entire contents of each of which are incorporated herein by reference thereto. In other example embodiments, the e-vaping device may include the features set forth in U.S. patent application Ser. No. 15/135,923 filed Apr. 22, 2016, and/or U.S. Pat. No. 9,289,014 issued Mar. 22, 2016, the entire contents of each of which is incorporated herein by this reference thereto. 
     In at least one example embodiment, the pre-vapor formulation is a material or combination of materials that may be transformed into a vapor. For example, the pre-vapor formulation may be a liquid, solid and/or gel formulation including, but not limited to, water, beads, solvents, active ingredients, ethanol, plant extracts, natural or artificial flavors, and/or vapor formers such as glycerin and propylene glycol. 
     In at least one example embodiment, the first section  15  may include the housing  30  extending in a longitudinal direction and an inner tube (or chimney)  70  coaxially positioned within the housing  30 . 
     In at least one example embodiment, a first connector piece  155  may include a male threaded section for effecting the connection between the first section  15  and the second section  20 . 
     In at least one example embodiment, at least two air inlets  55  may be included in the housing  30 . Alternatively, a single air inlet  55  may be included in the housing  30 . Such arrangement allows for placement of the air inlet  55  close to the connector  25  without occlusion by the presence of the first connector piece  155 . This arrangement may also reinforce the area of air inlets  55  to facilitate precise drilling of the air inlets  55 . 
     In at least one example embodiments, the air inlets  55  may be provided in the connector  25  instead of in the housing  30 . In other example embodiments, the connector  25  may not include threaded portions. 
     In at least one example embodiment, the at least one air inlet  55  may be formed in the housing  30 , adjacent the connector  25  to minimize the chance of an adult vaper&#39;s fingers occluding one of the ports and to control the resistance-to-draw (RTD) during vaping. In at least one example embodiment, the air inlet  55  may be machined into the housing  30  with precision tooling such that their diameters are closely controlled and replicated from one e-vaping device  010  to the next during manufacture. 
     In at least one example embodiment, the air inlets  55  may be sized and configured such that the e-vaping device  10  has a resistance-to-draw (RTD) in the range of from about 60 mm H 2 O to about 150 mm H 2 O. 
     In at least one example embodiment, a nose portion  110  of a gasket  65  may be fitted into a first end portion  105  of the inner tube  70 . An outer perimeter of the gasket  65  may provide a substantially tight seal with an interior surface  125  of the housing  30 . The gasket  65  may include a central channel  115  disposed between the inner passage  120  of the inner tube  70  and the interior of the mouth-end insert  35 , which may transport the vapor from the inner passage  120  to the mouth-end insert  35 . The mouth-end insert  35  includes at least two outlets  100 , which may be located off-axis from the longitudinal axis of the e-vaping device  10 . The outlets  100  may be angled outwardly in relation to the longitudinal axis of the e-vaping device  10 . The outlets  100  may be substantially uniformly distributed about the perimeter of the mouth-end insert  35  so as to substantially uniformly distribute vapor. 
     An absorbent material  205  surrounds a second end of the inner tube  70 . The absorbent material  205  is in the form of a disc having a central channel  210  therethrough. The central channel  210  is in communication with the inner passage  120  of the inner tube  70 . The absorbent material  205  is sized and configured to fit snugly between the inner tube and the inner surface  125  of the housing  30 . 
     In at least one example embodiment, the space defined between the gasket  65 , the absorbent material  205 , the housing  30 , and the inner tube  70  may establish the confines of the reservoir  95 . The reservoir  95  may contain a pre-vapor formulation, and optionally a storage medium (not shown) configured to store the pre-vapor formulation therein. The storage medium may include a winding of cotton gauze or other fibrous material about the inner tube  70 . 
     In at least one example embodiment, the reservoir  95  may at least partially surround the inner passage  120 . 
     In at least one example embodiment, the reservoir  95  may be sized and configured to hold enough pre-vapor formulation such that the e-vaping device  10  may be configured for vaping for at least about 200 seconds. Moreover, the e-vaping device  10  may be configured to allow each puff to last a maximum of about 5 seconds. 
     In at least one example embodiment, the storage medium may be a fibrous material including at least one of cotton, polyethylene, polyester, rayon and combinations thereof. The fibers may have a diameter ranging in size from about 6 microns to about 15 microns (e.g., about 8 microns to about 12 microns or about 9 microns to about 11 microns). The storage medium may be a sintered, porous or foamed material. Also, the fibers may be sized to be irrespirable and may have a cross-section which has a Y-shape, cross shape, clover shape or any other suitable shape. In at least one example embodiment, the reservoir  95  may include a filled tank lacking any storage medium and containing only pre-vapor formulation. 
     During vaping, pre-vapor formulation may be transferred from the reservoir  95  and/or storage medium to the proximity of the heating element  85  via capillary action of the absorbent material  205  and the porous material  90  coated on the heating element  85 . 
     In at least one example embodiment, the absorbent material  205  and the porous material  90  may include any suitable material or combination of materials. Examples of suitable materials may be, but not limited to, paper-, cellulosic-, glass-, ceramic- or graphite-based materials. The absorbent material  205  and/or the porous material  90  may have any suitable capillarity drawing action to accommodate pre-vapor formulations having different physical properties such as density, viscosity, surface tension and vapor pressure. The glass-based materials may be in the form of fibers and/or beads. The absorbent material  205  and/or the porous material  90  may be non-conductive. 
     In at least one example embodiment, the porous material  90  may include aluminum oxide, zirconium oxide, silicon dioxide, quartz, and combinations thereof. 
     In at least one example embodiment, the absorbent material  205  and/or the porous material  90  is chosen so that the porous material  90  does not loose structural integrity when saturated with the pre-vapor formulation. The absorbent material  205  and/or the porous material  90  may be hydrophilic. 
     In at least one example embodiment, the porous material  90  has a porosity of at least about 50% (e.g., at least about 60%, at least about 70%, at least about 80%, at least about 90%, or at least about 95%). Lower porosity requires more solid mass on the wire that increases the thermal latency and energy efficiency. The porous material  90  is substantially heat-resistant up to about 500° C. (e.g., up to about 450° C., up to about 400° C., up to about 350° C., or up to about 300° C.). 
     In at least one example embodiment, the porous material  90  is coated onto the heating element  85  by spraying, dipping, and/or adhering the porous material  90  to at least one surface of the heating element  85  as further discussed below. The coating of the porous material  90  may have a thickness of about 0.5 mm to about 1.0 mm (e.g., about 0.6 mm to about 0.9 mm or about 0.7 mm to about 0.8 mm). The thickness of the coating of the porous material  90  may be chosen to hold a sufficient amount of the pre-vapor formulation to form a desired amount of vapor per puff. The vaporizer  80  may include two or more different coatings. The coatings may each include the same or different porous materials and/or may have the same and/or different thicknesses, densities, and/or porosities. 
     In at least one example embodiment, the porous material  90  remains flexible after the porous material  90  is dried on the heating element  85  to form the vaporizer  80 . 
     For example, the vaporizer  80  may include the heating element  85  and a layer of paper coated on the heating element  85  with an adhesive. 
     In at least one example embodiment, the heating element  85  of the vaporizer  80  may include a wire, a wire coil, a spiral, a plate, a disc, a mesh, and/or any other suitable form. The wire may be a metal wire. At least one surface of the heating element  85  is coated with the porous material  90 . The porous material  90  is at least partially in direct physical contact with the absorbent material  205 . 
     In at least one example embodiment, the heating element  85  may be formed of any suitable electrically resistive materials. Examples of suitable electrically resistive materials may include, but not limited to, copper, titanium, zirconium, tantalum and metals from the platinum group. Examples of suitable metal alloys include, but not limited to, stainless steel, nickel, cobalt, chromium, aluminum-titanium-zirconium, hafnium, niobium, molybdenum, tantalum, tungsten, tin, gallium, manganese and iron-containing alloys, and super-alloys based on nickel, iron, cobalt, stainless steel. For example, the heating element  85  may be formed of nickel aluminide, a material with a layer of alumina on the surface, iron aluminide and other composite materials, the electrically resistive material may optionally be embedded in, encapsulated or coated with an insulating material or vice-versa, depending on the kinetics of energy transfer and the external physicochemical properties required. The heating element  85  may include at least one material selected from the group consisting of stainless steel, copper, copper alloys, nickel-chromium alloys, super alloys and combinations thereof. In an example embodiment, the heating element  85  may be formed of nickel-chromium alloys or iron-chromium alloys. 
     In at least one example embodiment, a first lead  75  is physically and electrically connected to the male threaded connector piece  155 . As shown, the male threaded first connector piece  155  is a hollow cylinder with male threads on a portion of the outer lateral surface. The connector piece is conductive, and may be formed or coated with a conductive material. A second lead  75 ′ is physically and electrically connected to a first conductive post  130 . The first conductive post  130  may be formed of a conductive material (e.g., stainless steel, copper, etc.), and may have a T-shaped cross-section as shown in  FIG. 2 . The first conductive post  130  nests within the hollow portion of the first connector piece  155 , and is electrically insulated from the first connecter piece  155  by an insulating shell  135 . The first conductive post  130  may be hollow as shown, and the hollow portion may be in fluid communication with the air passage  120 . Accordingly, the first connector piece  155  and the first conductive post  130  form respective external electrical connection to the heating element  85 . 
     In at least one example embodiment, the heating element  85  may heat pre-vapor formulation in the porous material  90  by thermal conduction. 
     As shown in  FIG. 2 , the second section  20  includes a power supply  145 , a control circuit  185 , and a sensor  190 . As shown, the control circuit  185  and the sensor  190  are disposed in the housing  30 ′. A female threaded second connector piece  160  forms a second end. As shown, the second connector piece  160  has a hollow cylinder shape with threading on an inner lateral surface. The inner diameter of the second connector piece  160  matches that of the outer diameter of the first connector piece  155  such that the two connector pieces  155 ,  160  may be threaded together to form the connection  25 . Furthermore, the second connector piece  160 , or at least the other lateral surface is conductive, for example, formed of or including a conductive material. As such, an electrical and physical connection occurs between the first and second connector pieces  155 ,  160  when connected. 
     As shown, a first lead  165  electrically connects the second connector piece  160  to the control circuit  185 . A second lead  170  electrically connects the control circuit  185  to a first terminal  180  of the power supply  145 . A third lead  175  electrically connects a second terminal  140  of the power supply  145  to the power terminal of the control circuit  185  to provide power to the control circuit  185 . The second terminal  140  of the power supply  145  is also physically and electrically connected to a second conductive post  150 . The second conductive post  150  may be formed of a conductive material (e.g., stainless steel, copper, etc.), and may have a T-shaped cross-section as shown in  FIG. 2 . The second conductive post  150  nests within the hollow portion of the second connector piece  160 , and is electrically insulated from the second connector piece  160  by a second insulating shell  215 . The second conductive post  150  may also be hollow as shown. When the first and second connector pieces  155 ,  160  are mated, the second conductive post  150  physically and electrically connects to the first conductive post  130 . Also, the hollow portion of the second conductive post  150  may be in fluid communication with the hollow portion of the first conductive post  130 . 
     While the first section  15  has been shown and described as having the male connector piece and the second section  20  has been shown and described as having the female connector piece, an alternative embodiment includes the opposite where the first section  15  has the female connector piece and the second section  20  has the male connector piece. 
     In at least one example embodiment, the power supply  145  includes a battery arranged in the e-vaping device  10 . The power supply  145  may be a Lithium-ion battery or one of its variants, for example a Lithium-ion polymer battery. Alternatively, the power supply  145  may be a nickel-metal hydride battery, a nickel cadmium battery, a lithium-manganese battery, a lithium-cobalt battery or a fuel cell. The e-vaping device  10  may be vapable by an adult vapor until the energy in the power supply  145  is depleted or in the case of lithium polymer battery, a minimum voltage cut-off level is achieved. 
     In at least one example embodiment, the power supply  145  is rechargeable. The second section  20  may include circuitry configured to allow the battery to be chargeable by an external charging device. To recharge the e-vaping device  10 , an USB charger or other suitable charger assembly may be used as described below. 
     In at least one example embodiment, the sensor  190  is configured to generate an output indicative of a magnitude and direction of airflow in the e-vaping device  10 . The control circuit  185  receives the output of the sensor  190 , and determines if (1) the direction of the airflow indicates a draw on the mouth-end insert  8  (versus blowing) and (2) the magnitude of the draw exceeds a threshold level. If these vaping conditions are met, the control circuit  185  electrically connects the power supply  145  to the heating element  85 ; thus, activating the heating element  85 . Namely, the control circuit  185  electrically connects the first and second leads  165 ,  170  (e.g., by activating a heater power control transistor forming part of the control circuit  185 ) such that the heating element  85  becomes electrically connected to the power supply  145 . In an alternative embodiment, the sensor  190  may indicate a pressure drop, and the control circuit  185  activates the heating element  85  in response thereto. 
     In at least one example embodiment, the control circuit  185  may also include a light  60 , which the control circuit  185  activates to glow when the heating element  85  is activated and/or the battery  145  is recharged. The light  60  may include one or more light-emitting diodes (LEDs). The LEDs may include one or more colors (e.g., white, yellow, red, green, blue, etc.). Moreover, the light  60  may be arranged to be visible to an adult vaper during vaping, and may be positioned between the first end  45  and the second end  50  of the e-vaping device  10 . In addition, the light  60  may be utilized for e-vaping system diagnostics or to indicate that recharging is in progress. The light  60  may also be configured such that the adult vaper may activate and/or deactivate the heater activation light  60  for privacy. 
     In at least one example embodiment, the control circuit  185  may include a time-period limiter. In another example embodiment, the control circuit  185  may include a manually operable switch for an adult vaper to initiate heating. The time-period of the electric current supply to the heating element  85  may be set or pre-set depending on the amount of pre-vapor formulation desired to be vaporized. 
     Next, operation of the e-vaping device to create a vapor will be described. For example, air is drawn primarily into the first section  15  through the at least one air inlet  55  in response to a draw on the mouth-end insert  35 . The air passes through the air inlet  55 , into the central channel  210  of the absorbent material  205 , into the inner passage  120 , and through the outlet  100  of the mouth-end insert  35 . If the control circuit  185  detects the vaping conditions discussed above, the control circuit  185  initiates power supply to the heating element  85 , such that the heating element  85  heats pre-vapor formulation in the porous material  90 . The vapor and air flowing through the inner passage  120  combine and exit the e-vaping device  10  via the outlet  100  of the mouth-end insert  35 . 
     When activated, the heating element  85  may heat a portion of the porous material  90  for less than about 10 seconds. 
     In at least one example embodiment, the first section  15  may be replaceable. In other words, once the pre-vapor formulation of the cartridge is depleted, only the first section  15  may be replaced. An alternate arrangement may include an example embodiment where the entire e-vaping device  10  may be disposed once the reservoir  95  is depleted. In at least one example embodiment, the e-vaping device  10  may be a one-piece e-vaping device. 
     In at least one example embodiment, the e-vaping device  10  may be about 80 mm to about 110 mm long and about 7 mm to about 8 mm in diameter. For example, in one example embodiment, the e-vaping device  10  may be about 84 mm long and may have a diameter of about 7.8 mm. 
     In at least one example embodiment, as shown in  FIG. 2 , the e-vaping device  10  the control circuit  200  is disposed on a rigid printed circuit board  410 . 
       FIG. 3  is an enlarged cross-sectional view of a vaporizer of the e-vaping device of  FIG. 2  according to at least one example embodiment. 
     In at least one example embodiment, as shown in  FIG. 3 , the vaporizer  80  includes the heating element  85  and the porous material  90 . As shown, the heating element  85  is in the form of a substantially straight wire formed of an electrically conductive material. The porous material  90  is coated on all sides of the heating element  85 . The electrical leads  75 ,  75 ′ are connected to the heating element  85  at ends of the wire. The leads  75 ,  75 ′ may be connected to the ends of the wire by crimping and/or spot welding. 
       FIG. 4  is an illustration of a vaporizer according to at least one example embodiment. 
     In at least one example embodiment, as shown in  FIG. 4 , the vaporizer  80  includes the heating element  85  and the porous material  90  as in  FIGS. 2-3 . As shown in  FIG. 4 , the heating element  85  is in the form of a spiral, formed of an electrically conductive wire. The porous material  90  is coated on sides of the wire between adjacent windings of the spiral. The electrical leads  75 ,  75 ′ are connected to the heating element  85  at ends of the wire. 
       FIG. 5  is an illustration of a vaporizer and an absorbent material according to at least one example embodiment. 
     In at least one example embodiment, as shown in  FIG. 5 , the vaporizer  80  includes the heating element and the porous material as in  FIGS. 2-4 . As shown in  FIG. 5 , the vaporizer has a generally sinuous shape. As shown, a side portion of the vaporizer  80  directly contacts the absorbent material  205 . The porous material  90  of the vaporizer  80  conveys the pre-vapor formulation in the absorbent material  205  to the heating element  85 . 
       FIG. 6  is an illustration of a vaporizer and an absorbent material according to at least one example embodiment. 
     In at least one example embodiment, as shown in  FIG. 6 , the vaporizer  80  includes the heating element  85  and the porous material  90  as in  FIGS. 2-5 . As shown in  FIG. 6 , the vaporizer  80  has a generally sinuous shape. As shown, an end portion of the vaporizer  80  directly contacts the absorbent material  205 . 
       FIG. 7  is an illustration of a vaporizer and an absorbent material according to at least one example embodiment. 
     In at least one example embodiment, as shown in  FIG. 7 , the vaporizer  80  includes the heating element and the porous material as in  FIGS. 2-5 . As shown in  FIG. 6 , the vaporizer  80  has a bell shape, and end portions of the vaporizer  80  directly contact the absorbent material  205 . 
       FIG. 8  is an illustration of a vaporizer and an absorbent material according to at least one example embodiment. 
     In at least one example embodiment, as shown in  FIG. 8 , the vaporizer  80  includes the heating element and the porous material as in  FIGS. 2-5 . As shown in  FIG. 8 , the vaporizer  80  is U-shaped, and a central portion of the vaporizer  80  directly contacts the absorbent material  205 . 
       FIG. 9  is a diagram of a method of forming a vaporizer according to at least one example embodiment. 
     In at least on example embodiment, a method of making the vaporizer of  FIGS. 1-8  includes combining S 295  the porous material  90  and at least one solvent to form a slurry. The method also includes applying S 300  the slurry to the heating element  85  to form the vaporizer  80  and drying S 305  the vaporizer  80 . Once the vaporizer  80  is dried, the method may also include forming S 310  the vaporizer  80  into a desired shape and/or configuration. 
     In at least one example embodiment, the slurry includes about 50% to about 99% (e.g., about 55% to about 95%, about 60% to about 90%, about 65% to about 85%, or about s 0% to about 80%) of the porous material 90 and about 1% to about 50% of the solvent (e.g. about 2% to about 45%, about 5% to about 40%, about 10% to about 35%, about 15% to about 30% or about 20% to about 25%). 
     In at least one example embodiment, as set forth above, the porous material  90  includes any suitable material or combination of materials. Examples of suitable materials may be, but riot limited to, paper-, cellulosic-, glass-, ceramic- or graphite-based materials. The porous material  90  may have any suitable capillarity drawing action to accommodate pre-vapor formulations having different physical properties such as density, viscosity, surface tension and vapor pressure. The glass-based materials may be in the form of fibers and/or beads. For example, the porous material  90  may include aluminum oxide, zirconium oxide, silicon dioxide, quartz, and combinations thereof. The porous material  90  is substantially heat resistant. 
     In at least one example embodiment, the solvent may include at least one of water, ethanol, and combinations thereof. In at least one example embodiment, the slurry may further include one or more of a dispersant and a binder, such as a polymeric binder. 
     In at least one example embodiment, the drying S 305  step may include drying the vaporizer  80  at ambient temperature for about 1 hour to about 36 hours (e.g., about 12 hours to about 24 hours or about 15 hours to about 20 hours). In at least one example embodiment, the drying S 305  step may include heating the vaporizer  80  at a temperature of at least about 100° F. (e.g., at least about 150° F. or about least about 200° F.) for about 10 minutes to about 36 hours (e.g., about 12 hours to about 24 hours or about 15 hours to about 20 hours). During the drying S 305  step, the solvent is evaporated leaving the coating of the porous material  90  on the heating element  85 . 
     For example, the combining S 295  step may include combining a cellulosic based material with water and applying S 300  the cellulosic material to the heating element  85  to form the vaporizer  80 . The vaporizer  80  including a coating of cellulosic material may be used in e-vaping devices  10  in which the heating temperature is controlled so as to be less than about 400° C. 
     In at least one example embodiment, once the coating is formed, the porous material  90  remains flexible so that the vaporizer  80  may be formed into a desired shaped and configuration. 
       FIG. 10  is a diagram of a method of forming a vaporizer according to at least one example embodiment. 
     In at least one example embodiment, the method is the same as in  FIG. 9  except that the forming S 310  step occurs before the porous material  90  is applied S 300  to the heating element  85 . In this method, the heating element  85  may be bent, curled, rolled, stamped, or otherwise shaped before the porous material  90  is applied. 
       FIG. 11  is a diagram of a method of forming a vaporizer according to at least one example embodiment. 
     In at least one example embodiment, as shown in  FIG. 11 , the applying step S 300  of  FIGS. 9 and 10  includes dipping S 315  the heating element  85  in the slurry to form the coating of the porous material  90  on the heating element  85 . The dipping S 315  step may include fully or partially submerging the heating element  85  in the slurry for about 1 second to about 10 minutes (e.g., about 30 seconds to about 5 minutes or about 1 minute to about 2 minutes). In at least one example embodiment, only a selected portion of the heating element  85  is dipped in the slurry. In other example embodiments, the entire heating element  85  is dipped in the slurry. 
     In at least one example embodiment, the heating element  85  may be dipped multiple times in one or more different slurries to form one or more different coatings on the heating element  85 . The different slurries may include the same or different porous materials, such that the different layers of the coatings may have the same or different densities and/or porosities. 
       FIG. 12  is a diagram of a method of forming a vaporizer according to at least one example embodiment. 
     In at least one example embodiment, as shown in  FIG. 12 , the applying step S 300  of  FIGS. 9 and 10  includes spraying S 320  the porous material  90  or slurry including the porous material  90  onto the heating element  85  to form the coating. The heating element  85  may be sprayed so that the coating is substantially uniform along the surface of the heating element  85  or so that the coating varies in thickness along the surface of the heating element  85 . For example, the heating element  85  may be sprayed such that the coating is thicker in a central portion of the heating element  85  than at side portions of the heating element  85  or vice versa. The coating may be patterned on the heating element  85  so that selected portions of the heating element  85  are coated with the porous material  90 . 
     In at least one example embodiment, the heating element  85  may be sprayed multiple times in one or more different slurries to form one or more. different coatings on the heating element  85 . The different slurries may include the same or different porous materials, such that the different layers of the coatings may have the same or different densities and/or porosities. 
       FIG. 13  is a diagram of a method of forming a vaporizer according to at least one example embodiment. 
     In at least one example embodiment, the applying step S 300  may include adhering S 325  the porous material  90  to the heating element  85  to form the vaporizer  80 . The adhering S 325  may include gluing or otherwise adhering the porous material  90  to the heating element  85 . For example, beads and fibers of a desired material may be glued to at least one surface of the heating element  85 . 
     In at least one example embodiment, the adhesive is a food grade adhesive that is generally recognized as safe (GRAS). The adhesive is also substantially heat resistant and/or substantially water and/or liquid resistant, such that the structural integrity of the coating is not affected by application or heat or liquids. 
     Example embodiments have been disclosed herein, it should be understood that other variations may be possible. Such variations are not to be regarded as a departure from the spirit and scope of the present disclosure, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.