Patent Publication Number: US-2023144614-A1

Title: Electronic smoking article

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation under 35 U.S.C. § 120 of U.S. application Ser. No. 16/985,398, filed Aug. 5, 2020, which is a continuation under 35 U.S.C. § 120 of U.S. application Ser. No. 15/898,751, filed Feb. 19, 2018, which is a continuation under 35 U.S.C. § 120 of U.S. application Ser. No. 14/333,999, filed Jul. 17, 2014, which claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 61/857,835, filed Jul. 24, 2013, the entire contents of each of which are incorporated herein by reference. 
    
    
     WORKING ENVIRONMENT 
     Many of the embodiments disclosed herein include electronic smoking articles or electronic vaping articles operable to deliver liquid from a liquid supply reservoir to a heater. The heater volatilizes a liquid to form an aerosol. 
     SUMMARY 
     An electronic smoking article or electronic vaping article may include a reservoir containing a liquid material and having an outlet, a capillary, a heater operable to heat the capillary to a temperature sufficient to volatilize liquid in the capillary, and a shuttle valve between the outlet of the reservoir and the capillary inlet. The shuttle valve includes a housing with a cavity, a plunger movable between a retracted position and an open position, and at least two spaced apart seals. The shuttle valve is operable to prevent release of liquid material from the reservoir when the shuttle valve is in a retracted position and to release liquid material from the reservoir to the capillary inlet when the shuttle valve is in an open position. 
     A method of delivering a liquid to an electronic smoking article or electronic vaping article may include controlling a flow of the liquid with a valve. The controlling step may include establishing communication of a reservoir with an aerosolizer while operating the aerosolizer and closing the communication. The closing includes communicating the aerosolizer with a flow-back cavity separate of the reservoir. At least some residual liquid is drawn back from the aerosolizer upon the closing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a side view of an electronic smoking article. 
         FIG.  2    is a side view of an electronic smoking article including a shuttle valve. 
         FIG.  3    is a side view of a second embodiment of an electronic smoking article including a shuttle valve. 
         FIG.  4    is a side view of a third embodiment of an electronic smoking article including a shuttle valve. 
         FIG.  5    is a perspective view of a shuttle valve in a closed position. 
         FIG.  6    is a perspective view of the shuttle valve of  FIG.  4    in an open position. 
         FIG.  7    is a side view of another embodiment of an electronic smoking article including a shuttle valve and a sheath flow and aerosol promoter (SFAP) insert. 
         FIG.  8    is a side view of another embodiment of an electronic smoking article including a shuttle valve and a sheath flow and aerosol promoter (SFAP) insert. 
         FIG.  9    is a perspective view of a sheath flow and aerosol promoter (SFAP) insert for use in an electronic smoking article. 
         FIG.  10    is a cross-sectional view of the SFAP insert along line A-A of  FIG.  9   . 
     
    
    
     DETAILED DESCRIPTION 
     An electronic smoking article such as an electronic smoking article includes a manually operated shuttle valve operable to control flow of a liquid material from a pressurized liquid supply (reservoir) to a capillary, prevent leaks, and avoid excessive drawback of liquid from the capillary and introduction of air bubbles to the reservoir. As used herein, the term “electronic smoking article” is inclusive of all types of electronic smoking articles, regardless of form, size, or shape, including electronic cigarettes, electronic cigars, electronic pipes, electronic hookahs, and the like. The liquid aerosol formulation can include nicotine or be nicotine free. Moreover, the liquid aerosol formulation can include tobacco flavors or instead, or in combination include other suitable flavors. 
     Optionally, the electronic smoking article such as an electronic smoking article can also include a sheath flow and aerosol promoter (SFAP) insert operable to produce and deliver a more fully developed aerosol. Once an aerosol is generated, the aerosol flows into the SFAP insert and is cooled by air which enters the electronic smoking article downstream of a heater. Because the air enters downstream of the heater and upstream of the SFAP insert, the aerosol is quickly cooled to produce smaller particles. The SFAP insert includes a constriction which can enhance cooling of the aerosol by reducing the cross-section of the aerosol flow so as to increase the rate of heat transfer from the center of the aerosol flow to walls of the SFAP insert. The increased cooling rate increases the rate of particle formation resulting in smaller particle sizes. Channels provided on an exterior of the SFAP allow aerosol-free (sheath) air to be drawn into a mixing chamber downstream of the constriction where the sheath air produces a boundary layer that is operable to minimize condensation of the aerosol on walls of the SFAP insert so as to increase the delivery rate (efficiency) of the aerosol. 
     As shown in  FIGS.  1  and  2   , an electronic smoking article  60  comprises a replaceable cartridge (or first section)  70  and a reusable fixture (or second section)  72 , which are coupled together at a threaded joint  74  or by other convenience such as a snug-fit, snap-fit, detent, clamp and/or clasp. 
     As shown in  FIG.  2   , the first section  70  can house a mouth-end insert  20 , optionally a SFAP insert  220  (shown in  FIGS.  7  and  8   ), a capillary aerosol generator including a capillary  18 , a heater  19  to heat at least a portion of the capillary (or capillary tube)  18 , a reservoir  14 , and a shuttle valve  40 . The second section  72  can house a power supply  12  and control circuitry  11 . The threaded portion  74  of the second section  72  can be connected to a battery charger when not connected to the first section  70  for use so as to charge the battery. 
     As shown in  FIGS.  3  and  4   , the electronic smoking article  60  can also include a middle section (third section)  73 . The middle section  73 , shown in  FIG.  3   , can house the reservoir  14  and the valve  40 , while the first section  70  can house a capillary aerosol generator including a capillary  18 , a heater  19  to heat at least a portion of the capillary  18  and a mouth-end insert  20 . As shown in  FIG.  4   , the middle section  73  can house the reservoir  14  and the first section  70  can house the valve  40  and a capillary aerosol generator including a capillary  18 , a heater  19 , and a mouth-end insert  20 . 
     The middle section  73  of  FIGS.  3  and  4    can be adapted to be fitted with a threaded joint  74 ′ at an upstream end of the first section  70  and a threaded joint  74  at a downstream end of the second section  72 . 
     Preferably, the first section  70 , the second section  72  and the optional third section  73  include an outer cylindrical housing (casing)  22  extending in a longitudinal direction along the length of the electronic smoking article  60 . Moreover, in one embodiment, the middle section  73  is disposable and the first section  70  and/or second section  72  are reusable. In another embodiment, the first section  70  is also disposable so as to avoid the need for cleaning the capillary  18  and/or heater  19 . The sections  70 ,  72 ,  73  can be attached by threaded connections whereby the middle section  73  can be replaced when the reservoir  14  is used up. 
     In another embodiment, the housing  22  may comprise a single, unitary tube, without any threaded connections. 
     In the preferred embodiment, as shown in  FIGS.  2 - 8   , the reservoir  14  is a pressurized reservoir. For example, the reservoir  14  can be pressurized using a pressurization arrangement  405  (shown in  FIGS.  2 - 4  and  7 - 8   ) which applies constant pressure to the reservoir  14 . For example, the pressurization arrangement  405  can include an internal or external spring and plate (or piston) arrangement which constantly applies pressure to the reservoir  14 . Alternatively, the reservoir  14  can be compressible and positioned between a pressurization arrangement  405  including two plates that are connected by springs or the reservoir  14  could be compressible and positioned between the outer casing and a plate that are connected by a spring so that the plate applies pressure to the reservoir  14 . 
     Preferably, the pressurized reservoir  14  has an outlet  16  which in effect, is an inlet  16  to the shuttle valve  40  that controls fluid communication with the capillary  18 . The shuttle valve  40  is positioned between the outlet  16  of the reservoir  14  and an outlet passage  105 , which in turn communicates with the capillary  18  so as to control delivery of liquid material from the reservoir  14 . 
     Preferably, the pressurized reservoir  14  extends longitudinally within the outer cylindrical casing  22  of the first section  70  (shown in  FIG.  2   ) or the middle section  73  (shown in  FIGS.  3  and  4   ). The pressurized reservoir  14  comprises a liquid material which is volatilized when heated and forms an aerosol when discharged from the capillary  18 . 
     Preferably, the liquid material includes a tobacco-containing material including volatile tobacco flavor compounds which are released from the liquid upon heating. The liquid may also be a tobacco flavor containing material and/or a nicotine-containing material. Alternatively, or in addition, the liquid may include a non-tobacco material and/or may be nicotine-free. For example, the liquid may include water, solvents, ethanol, plant extracts and natural or artificial flavors. Preferably, the liquid further includes an aerosol former. Examples of suitable aerosol formers are glycerine and propylene glycol. 
     Referring now to  FIG.  5   , in an embodiment, the shuttle valve  40  includes a plunger  13  integrally formed with a “push-button” actuator  100 . The plunger  13  is movable along a cavity  57  of a valve housing  101  from a first, retracted position which is shown in  FIG.  5   , and a second open position as shown in  FIG.  6   . The plunger  13  includes a pair of spaced-apart seals (o-rings)  300 ,  302 , which sealingly slide along the walls of the valve housing  101  which define the cavity  57 . The plunger  13  and the cavity  57  extend transversely to the longitudinal axis of the electronic smoking article  60 . The outlet  16  of the reservoir is in fluid communication with the cavity  57  at a first location  103  and the outlet passage  105  of the valve  40  with cavity  57  at a second location  107 , which is spaced from the first location  103 . The spacing between the first location  103  and the second location  107  and the spacing between the first and second seals  300 ,  302  are such that, when the plunger  13  is in its retracted position, the inlet passage  16  of the valve  40  is disposed between seals  300 ,  302 , and the outlet passage  105  of the valve  40  is disposed below (on the other side) of the second, lower seal  302 . Accordingly, the inlet passage  16  is closed and out of communication with the outlet passage  105  of the valve  40 . 
     Still referring to  FIG.  5   , when the plunger  13  is in its retracted position, the lowest-most portion of the plunger  13  is spaced from a lowest-most portion of the cavity  57  adjacent a bottom portion  109  of the valve housing  101  so as to define a draw-back cavity  89 . The outlet passage  105  is at least partially disposed below the lowest-most portion of the retracted plunger  13  such that communication is established between the outlet passage  105  and the draw-back cavity  89  as the plunger  13  returns to its retracted position as shown in  FIG.  5   . Thereupon, liquid that may have remained in the valve outlet passage  105  and/or in portions of the capillary  18  upon conclusion of an operation of the device is drawn back into the draw-back cavity  89 . The draw-back of residual liquid avoids sputtering and other inconsistencies when the capillary  18  undergoes its next operation (aerosolization). It also avoids air being drawn back into the reservoir  14 , which might otherwise frustrate precise operation of the liquid-feed. 
     The plunger  13  is sized such that the cavity  57  is slightly bigger than the diameter and/or dimensions of the plunger  13  such that liquid can flow in the space between the plunger  13  and the walls of the cavity  57 . 
     When the shuttle valve  40  is closed, the actuator  100  extends through the outer casing  22  of the electronic smoking article  60 . A spring  88  biases the plunger  13  toward its retracted position and provides resistance when pressing the actuator  100 . When the spring  88  is at rest, the shuttle valve  40  remains closed. 
     In one embodiment, a bottom portion  109  of the valve housing  101  adjacent the draw-back cavity  89  portion of the cavity  57  can be formed of, or provided with, a deformable material, such as rubber. Use of such a deformable material may aid in relieving pressure within the bottom portion  109  as the shuttle valve  40  is activated (or opened). 
     Preferably, the first seal  300  and a second seal  302  are  0 -rings, each of which encircles a periphery of the plunger  13  along the length thereof. Also preferably, the first seal  300  and the second seal  302  are arranged such that when the shuttle valve  40  is in the open position, as shown in  FIG.  6   , both the inlet  16  and the outlet  105  of the valve  40  are positioned between the location of the first seal  300  and the second seal  302  along the plunger  13 , such that liquid may flow from the reservoir, through the valve  40  and into the capillary  18 . 
     When the shuttle valve  40  is in the closed position, as shown in  FIG.  5   , the first seal  300  and the second seal  302  are positioned so that only the valve inlet  16  is between the first seal  300  and the second seal  302 . The liquid from the reservoir is trapped in the annular space around the periphery of the plunger  13  between the first seal  300  and the second seal  302 . Liquid is blocked from flowing into the outlet  105  of the valve when the shuttle valve  40  is in the closed position. In addition, when the shuttle valve  40  is in the closed position, the plunger  13  does not extend to the bottom  109  of the valve housing  101  so as to define the draw-back cavity  89  below the plunger  13 . Preferably, the outlet passage  105  of the valve  40  is in fluid communication with the draw-back cavity  89  so that a minute amount of liquid remaining in the inlet end  62  of the capillary  18  can flow back into the draw-back cavity  89 . 
     Referring now to  FIG.  6   , in use, a smoker (vaporer) presses the actuator  100  to open the shuttle valve  40  to release liquid from the reservoir via the valve inlet  16  and the outlet passage  105  to the inlet end  62  of the capillary  18 . Once the actuator  100  is pressed, the control circuitry  11  communicates with the power supply  12  to activate the heater  19  so that the heater  19  is heated for so long as liquid is being released from the reservoir  14  to volatilize the liquid. Upon discharge from the heated capillary  18 , the volatilized material expands, mixes with air and forms an aerosol. The control circuitry further includes a heater activation light  27  at an upstream end of the electronic smoking article  60 . The heater activation light  27  is operable to light up when the heater  19  is activated. 
     Once the actuator  100  is released, the shuttle valve  40  closes and liquid can no longer flow from the reservoir  14  to the capillary  18 . Advantageously, the smoker can tailor the smoking (vaping) experience by pressing the actuator  100  for a longer period of time to produce a larger amount of aerosol or for a shorter period of time to produce a smaller amount of aerosol. 
     In the preferred embodiment, when the shuttle valve  40  is opened, the inlet end  62  of the capillary  18  is in fluid communication with the outlet  16  of the reservoir  14 , and an outlet end  63  of the capillary (shown in  FIGS.  2 ,  3 ,  4 ,  7  and  8   ) is operable to expel volatilized liquid material from the capillary  18 . 
     Preferably, the capillary  18  has an internal diameter of 0.01 to 10 mm, preferably 0.05 to 1 mm, and more preferably 0.05 to 0.4 mm. For example, the capillary can have an internal diameter of about 0.05 mm. Capillaries of smaller internal diameter provide more efficient heat transfer to the fluid because, with the shorter distance to the center of the fluid, less energy and time is required to vaporize the liquid. 
     Also preferably, the capillary  18  may have a length of about 5 mm to about 72 mm, more preferably about 10 mm to about 60 mm or about 20 mm to about 50 mm. For example, the capillary  18  can be about 50 mm in length and arranged such that a downstream, about 40 mm long, coiled portion of the capillary  18  forms a heated section  202  and an upstream, about 10 mm long, portion of the capillary  18  remains relatively unheated when the heater  19  is activated (shown in  FIG.  2   ). 
     In one embodiment, the capillary  18  is substantially straight. In other embodiments, the capillary  18  is coiled and/or includes one or more bends therein to conserve space. 
     In the preferred embodiment, the capillary  18  is formed of a conductive material, and thus acts as its own heater  19  by passing current through the capillary. The capillary  18  may be any electrically conductive material capable of being resistively heated, while retaining the necessary structural integrity at the operating temperatures experienced by the capillary  18 , and which is non-reactive with the liquid material. Suitable materials for forming the capillary  18  are selected from the group consisting of stainless steel, copper, copper alloys, porous ceramic materials coated with film resistive material, Inconel® available from Special Metals Corporation, which is a nickel-chromium alloy, nichrome, which is also a nickel-chromium alloy, and combinations thereof. 
     In one embodiment, the capillary  18  is a stainless steel capillary  18 , which serves as a heater  19  via electrical leads  26  attached thereto for passage of direct or alternating current along a length of the capillary  18 . Thus, the stainless steel capillary  18  is heated by resistance heating. The stainless steel capillary  18  is preferably circular in cross section. The capillary  18  may be of tubing suitable for use as a hypodermic needle of various gauges. For example, the capillary  18  may comprise a 32 gauge needle having an internal diameter of 0.11 mm or a 26 gauge needle having an internal diameter of 0.26 mm. 
     In another embodiment, the capillary  18  may be a non-metallic tube such as, for example, a glass tube. In such an embodiment, the heater  19  is formed of a conductive material capable of being resistively heated, such as, for example, stainless steel, nichrome or platinum wire, arranged along the glass tube. When the heater arranged along the glass tube is heated, liquid material in the capillary  18  is heated to a temperature sufficient to at least partially volatilize liquid material in the capillary  18 . 
     Preferably, at least two electrical leads  26  are bonded to a metallic capillary  18 . In the preferred embodiment, the electrical leads  26  are brazed to the capillary  18 . Preferably, one electrical lead  26  is brazed to a first, upstream portion  104  of the capillary  18  and a second electrical lead  26  is brazed to a downstream, end portion  102  of the capillary  18 , as shown in  FIG.  2   . 
     In use, once the capillary  18  is heated, the liquid material contained within a heated portion of the capillary  18  is volatilized and ejected out of the outlet  63  (shown in  FIGS.  2 ,  7  and  8   ) where it expands and mixes with air and forms an aerosol in a mixing chamber  46 . The mixing chamber  46  can be positioned upstream of a sheath flow and aerosol promoter (SFAP) insert  220 , as shown in  FIG.  7   , or in the SFAP insert  220  as shown in  FIG.  8   . 
     Preferably, the electronic smoking article  60  also includes at least one air inlet  44  operable to deliver at least some air to the mixing chamber  46  and to a growth cavity  240 , downstream of the mixing chamber  46 . Preferably, air inlets  44  are arranged downstream of the capillary  18  so as to minimize drawing air along the capillary and thereby avoid cooling of the capillary  18  during heating cycles. 
     In one embodiment, the air inlets  44  can be upstream of a downstream end  281  of the SFAP insert  220 , as shown in  FIGS.  7 - 9   . In other embodiments, the air inlets  44  can be superposed with the SFAP insert  220 . Optionally, air holes  225  in a wall  227  of the SFAP insert  220  (shown in  FIG.  9   ), can allow some air to enter the mixing chamber  46  of the SFAP insert  220 . In addition to the air holes  225 , as shown in  FIG.  9   , the SFAP insert  220  can include a lip portion  237  (shown in  FIG.  8   ) at an upstream end thereof, which prevents passage of air. Alternatively, the lip portion  237  can be arranged such that air can travel through a gap  216  (shown in  FIG.  7   ) between the lip  237  of the SFAP insert  220  and an inner surface  231  of the outer casing  22  prior to entering the mixing chamber  46  within the SFAP insert  220 . 
     Air that enters via the air inlets  44  (“sheath air”) can flow along an external surface of the SFAP insert  220  via channels  229  extending longitudinally along the external surface of the SFAP insert  220  between vanes  245  as shown in  FIGS.  9  and  10   . The vanes  245  extend longitudinally along an outer surface  221  of the SFAP insert  220  and in spaced apart relation so as to form the channels  229  therebetween. Once the aerosol passes through a constriction  230  in the SFAP insert  220 , as shown in  FIGS.  7  and  8   , the aerosol enters the downstream growth cavity  240  where the aerosol can mix with sheath air and the sheath air can act as a barrier between an inner surface of the growth cavity  240  and the aerosol so as to minimize condensation of the aerosol on walls of the growth cavity  240 . 
     In the embodiment shown in  FIG.  7   , in which the SFAP insert  220  includes the lip portion  237  spaced from the inner surface  231  of the outer casing  22 , and air that enters the air inlets  44  is split into two air streams. The first air stream travels through the channels  229  on the outside of the insert  220 . The remaining air flows upstream through the gap  235 , around the lip portion  237 , which in this embodiment does not extend to the inner surface of the outer casing  22 , and through the constriction  230  along with the volatilized liquid material. While not wishing to be bound by theory, it is believed that about 5% to about 20% of the air passing through the constriction  230  is sheath air. 
     In the preferred embodiment, the at least one air inlet  44  includes one or two air inlets. Alternatively, there may be three, four, five or more air inlets. Altering the size and number of air inlets  44  can also aid in establishing the resistance to draw of the electronic smoking article  60 . Preferably, the air inlets  44  communicate with the channels  229  arranged between the SFAP insert  220  and the inner surface  231  of the outer casing  22 . 
     In the preferred embodiment, the SFAP insert  220  is operable to provide an aerosol that is similar to cigarette smoke, has a mass median particle diameter of less than 1 micron and aerosol delivery rates of at least about 0.01 mg/cm 3 . Once the aerosol is formed at the heater, the aerosol passes to the mixing chamber  46  where the aerosol mixes with sheath air and is cooled. The sheath air causes the aerosol to supersaturate and nucleate to form new particles. The faster the aerosol is cooled the smaller the final diameter of the aerosol particles. When air is limited, the aerosol will not cool as fast and the particles will be larger. Moreover, the aerosol may condense on surfaces of the electronic smoking article resulting in lower delivery rates. The SFAP insert  220  prevents or at least abates the tendency of the aerosol to condense on surfaces of the electronic smoking article and quickly cools the aerosol so as to produce a small particle size and high delivery rates as compared to electronic smoking articles not including the SFAP insert as described herein. 
     Accordingly, the SFAP insert  220  can include a mixing chamber  46  adjacent to an upstream end of the SFAP insert  220  (as shown in  FIG.  7   ) or inside the SFAP insert  220  (as shown in  FIG.  8   ). The mixing chamber  46  leads to the constriction  230  having a reduced diameter as compared to the mixing chamber  46 . Preferably, the diameter of the constriction  230  is about 0.125 inch to about 0.1875 inch and is about 0.25 inch to about 0.5 inch long. The constriction  230  leads to the growth cavity  240  which is preferably about 2 inches in length and has a diameter of about 0.3125 inch. Preferably, the SFAP insert  220  is spaced about 0.2 to about 0.4 inch from the outlet  63  of the capillary  18 . Moreover, the channels  229  formed on the outer surface  221  of the SFAP insert  220  form about 10% of the total cross-sectional area of the SFAP insert  220  and allow sheath air to pass between the outer surface  221  of the SFAP insert  220  and the inner surface  231  of the outer cylindrical casing  22 . 
     In the embodiments described herein, the valve  40  and its plunger  13  operate in a transverse orientation. Alternatively, the valve  40  may be oriented in a longitudinal orientation. In either orientation, a servo or cam or other suitable arrangement may be used instead or in combination with the “push-button” actuator  100 . In addition, the valve  40  is adaptable to operation in electronic smoking articles which include a heater coil and wick to volatilize (aerosolize) liquid, such that the valve  40  delivers liquid to the heater coil and wick. 
     In the preferred embodiment, the power supply  12  includes a battery arranged in the electronic smoking article  60 . The power supply  12  is operable to apply voltage across the heater  19  associated with the capillary  18 . Thus, the heater  19  is heated to a temperature sufficient to volatilize liquid material according to a power cycle of either a predetermined time period, such as a 2 to 10 second period, or for so long as pressure is applied to the actuator  100  which opens the shuttle valve  40 . 
     Preferably, the electrical contacts or connection between the heater  19  and the electrical leads  26  are highly conductive and temperature resistant while the heater  19  is highly resistive so that heat generation occurs primarily along the heater  19  and not at the contacts. 
     The battery can be a Lithium-ion battery or one of its variants, for example a Lithium-ion polymer battery. Alternatively, the battery may be a Nickel-metal hydride battery, a Nickel cadmium battery, a Lithium-manganese battery, a Lithium-cobalt battery or a fuel cell. In that case, preferably, the electronic smoking article  60  is usable by a smoker until the energy in the power supply is depleted. Alternatively, the power supply  12  may be rechargeable and include circuitry allowing the battery to be chargeable by an external charging device. In that case, preferably the circuitry, when charged, provides power for a pre-determined number of puffs, after which the circuitry must be re-connected to an external charging device. 
     In the preferred embodiment, the reservoir  14  includes a liquid material which has a boiling point suitable for use in the electronic smoking article  60 . If the boiling point is too high, the heater  19  will not be able to vaporize liquid in the capillary  18 . However, if the boiling point is too low, the liquid may vaporize without the heater  19  being activated. 
     In use, liquid material is transferred from the reservoir  14  to the heated capillary  18  by manually operating the shuttle valve  40 . 
     As shown in  FIGS.  2 ,  3 ,  7  and  8    the electronic smoking article  60  further includes a mouth-end insert  20  having at least two off-axis, preferably diverging outlets  21 . Preferably, the mouth-end insert  20  is in fluid communication with the mixing chamber  46  and includes at least two diverging outlets  21 . (e.g. 3, 4, 5, or preferably 6 to 8 outlets or more). Preferably, the outlets  21  of the mouth-end insert  20  are located at ends of off-axis passages and are angled outwardly in relation to the longitudinal direction of the electronic smoking article  60  (i.e., divergently). As used herein, the term “off-axis” denotes at an angle to the longitudinal direction of the electronic smoking article. Also preferably, the mouth-end   insert (or flow guide)  20  includes outlets uniformly distributed around the mouth-end insert  20  so as to substantially uniformly distribute aerosol in a smoker&#39;s mouth during use. Thus, as the aerosol passes into a smoker&#39;s mouth, the aerosol enters the mouth and moves in different directions so as to provide a full mouth feel as compared to electronic smoking articles having an on-axis single orifice which directs the aerosol to a single location in a smoker&#39;s mouth. 
     In addition, the outlets  21  and off-axis passages are arranged such that droplets of unaerosolized liquid material carried in the aerosol impact interior surfaces of the mouth-end insert  20  and/or interior surfaces of the off-axis passages such that the droplets are removed or broken apart. In the preferred embodiment, the outlets  21  of the mouth-end insert  20  are located at the ends of the off-axis passages and are angled at about 5° to about 60° with respect to the central longitudinal axis of the electronic smoking article  60  so as to more completely distribute aerosol throughout a mouth of a smoker during use and to remove droplets. 
     Preferably, each outlet  21  has a diameter of about 0.015 inch to about 0.090 inch (e.g., about 0.020 inch to about 0.040 inch or about 0.028 inch to about 0.038 inch). The size of the outlets  21  and off-axis passages along with the number of outlets  21  can be selected to adjust the resistance to draw (RTD) of the electronic smoking article  60 , if desired. 
     In a preferred embodiment, the electronic smoking article  60  is about the same size as a conventional smoking article. In some embodiments, the electronic smoking article  60  can be about 80 mm to about 110 mm long, preferably about 80 mm to about 100 mm long and about 7 mm to about 8 mm in diameter. For example, in an embodiment, the electronic smoking article is about 84 mm long and has a diameter of about 7.8 mm. 
     The outer cylindrical casing  22  of the electronic smoking article  60  may be formed of any suitable material or combination of materials. Preferably, the outer cylindrical casing  22  is formed of metal and is part of the electrical circuit. Examples of other suitable materials include metals, alloys, plastics or composite materials containing one or more of those materials, or thermoplastics that are suitable for food or pharmaceutical applications, for example polypropylene, polyetheretherketone (PEEK), ceramic, low density polyethylene (LDPE) and high density polyethylene (HDPE). Preferably, the material is light and non-brittle. The outer cylindrical casing  22  can be any suitable color and/or can include graphics or other indicia printed thereon. 
     In an embodiment, the volatilized material formed as described herein can at least partially condense to form an aerosol including particles. Preferably, the particles contained in the vapor and/or aerosol range in size from about 0.5 micron to about 1 micron or about 1 micron to about 4 microns. In the preferred embodiment, the vapor and/or aerosol has particles of about 3.3 microns or less, more preferably about 2 microns or less. Also preferably, the particles are substantially uniform throughout the vapor and/or aerosol. 
     When the word “about” is used in this specification in connection with a numerical value, it is intended that the associated numerical value include a tolerance of ±10% around the stated numerical value. Moreover, when reference is made to percentages in this specification, it is intended that those percentages are based on weight, i.e., weight percentages. 
     Moreover, when the words “generally” and “substantially” are used in connection with geometric shapes, it is intended that precision of the geometric shape is not required but that latitude for the shape is within the scope of the disclosure. When used with geometric terms, the words “generally” and “substantially” are intended to encompass not only features which meet the strict definitions but also features which fairly approximate the strict definitions. 
     It will now be apparent that a new, improved, and nonobvious electronic smoking article has been described in this specification with sufficient particularity as to be understood by one of ordinary skill in the art. Moreover, it will be apparent to those skilled in the art that numerous modifications, variations, substitutions, and equivalents exist for features of the electronic smoking article which do not materially depart from the spirit and scope of the invention. Accordingly, it is expressly intended that all such modifications, variations, substitutions, and equivalents which fall within the spirit and scope of the invention as defined by the appended claims shall be embraced by the appended claims.