Electronic smoking article

• US 10,136,678 B2
• Filed: 08/16/2017
• Issued: 11/27/2018
• Est. Priority Date: 02/22/2013
• Status: Active Grant

• Current Assignee: Altria Client Services LLC (Altria Group, Inc.)
• Original Assignee: Altria Client Services LLC (Altria Group, Inc.)
• Inventors: Plunkett, Susan E., Kane, David B.
• Primary Examiner(s): Yaary, Eric
• Application Number:
  US15/678,402
• Publication Number:
  US 20170340019A1
• Time in Patent Office: 468 Days
• CPC Class Codes: A24F 40/10 Devices using liquid inhalable precursors
• CPC Class Codes: A24F 40/40 Constructional details, e.g. connection of cartridges and battery parts
• CPC Class Codes: A24F 40/44 Wicks
• CPC Class Codes: A24F 40/46 Shape or structure of electric heating means
• CPC Class Codes: A24F 40/50 Control or monitoring

Abstract

An electronic smoking article includes a liquid supply region including liquid material and a heater-wick element operable to wick liquid material and heat the liquid material to a temperature sufficient to vaporize the liquid material and form an aerosol. The heater-wick element is formed of a carbon or graphite foam.

Claims

1. An electronic vaping device comprising:

an integral heater-wick element configured to draw a pre-vapor formulation from a supply region and to heat the pre-vapor formulation to produce a vapor, the integral heater-wick element formed of a foamed carbon, the foamed carbon having impurities of less than about 100 ppm and a heat capacity of about 0.5 to 1.0 J/g-K.

2. The electronic vaping device of claim 1, wherein the foamed carbon has an electrical resistance ranging from about 0.3 to 10 ohms.

3. The electronic vaping device of claim 1, wherein the foamed carbon has an electrical resistance ranging from about 0.8 to 5 ohms.

4. The electronic vaping device of claim 1, wherein the foamed carbon has impurities of less than about 10 ppm.

5. The electronic vaping device of claim 1, wherein the foamed carbon is resistant to oxidation up to at least about 400°

C. in an oxygen atmosphere.

6. The electronic vaping device of claim 1, wherein the foamed carbon has a density of about 0.1 to 1.0 g/cc.

7. The electronic vaping device of claim 1, wherein the foamed carbon has an open porosity of at least about 90%.

8. The electronic vaping device of claim 1, wherein the foamed carbon has an open porosity of at least about 95%.

9. The electronic vaping device of claim 1, wherein the foamed carbon has a total porosity of at least about 70%.

10. The electronic vaping device of claim 1, wherein the foamed carbon has a total porosity of at least about 75%.

11. The electronic vaping device of claim 1, wherein the foamed carbon is a non-ceramic.

12. The electronic vaping device of claim 1, wherein the foamed carbon is a graphite foam or a carbon foam.

13. The electronic vaping device of claim 1, wherein the integral heater-wick element is structured to protect the pre-vapor formulation in the supply region from degradation by inhibiting an ingress of ambient oxygen into the supply region.

14. The electronic vaping device of claim 1, wherein the integral heater-wick element has a length ranging from about 10 to 15 mm and a width ranging from about 0.5 to 2.0 mm.

15. The electronic vaping device of claim 1, wherein the integral heater-wick element has a length of about 12 mm or less and a width of about 1.5 mm or less.

16. The electronic vaping device of claim 1, further comprising:

an electrical lead that is directly inserted into the integral heater-wick element to establish an electrical connection without soldering or brazing.

17. The electronic vaping device of claim 1, further comprising:

control circuitry electrically connected to the integral heater-wick element, the control circuitry configured to apply a voltage to the integral heater-wick element in response to a pressure drop or in response to a manually-operable switch.

18. A method of producing a vapor in an electronic vaping device, comprising:

drawing a pre-vapor formulation from a supply region with an integral heater-wick element, the integral heater-wick element formed of a foamed carbon, the foamed carbon having impurities of less than about 100 ppm and a heat capacity of about 0.5 to 1.0 J/g-K; and

heating the pre-vapor formulation from the supply region with the integral heater-wick element to produce a vapor.

19. The method of claim 18, wherein the heating includes applying a voltage to the integral heater-wick element in response to a pressure drop or in response to a manually-operable switch.