Abstract
A smoking article is provided, including a carbonaceous combustible heat source, an aerosol-forming substrate, and a wrapper circumscribing at least the heat source and the aerosol-forming substrate. One or more heat conducting elements overlie a rear portion of the heat source and an adjacent front portion of the aerosol-forming substrate. At least one heat conducting element includes a patch of thermally conductive printable medium printed onto the wrapper. Also provided is a method for applying heat conducting patches onto a web of smoking article wrapper material, wherein at least some of the patches include an area of thermally conductive printable medium.
Claims
1.-14. (canceled)
15. A smoking article, comprising: a carbonaceous combustible heat source; an aerosol-forming substrate; a wrapper circumscribing at least the carbonaceous combustible heat source and the aerosol-forming substrate; and one or more heat conducting elements overlying a rear portion of the carbonaceous combustible heat source and an adjacent front portion of the aerosol-forming substrate, wherein at least one heat conducting element of said one or more heat conducting elements comprises a patch of thermally conductive printable medium printed onto the wrapper.
16. The smoking article of claim 15, wherein the one or more heat conducting elements comprises a first heat conducting element disposed on an inner surface of the wrapper such that the first heat conducting element is in direct contact with the rear portion of the carbonaceous combustible heat source and the adjacent front portion of the aerosol-forming substrate.
17. The smoking article of claim 16, wherein the one or more heat conducting elements further comprises a second heat conducting element around at least a portion of the first heat conducting element and disposed on an outer surface of the wrapper.
18. The smoking article of claim 15, wherein the patch of thermally conductive printable medium is printed onto an outer surface of the wrapper.
19. A method for applying heat conducting patches onto a web of smoking article wrapper material, each heat conducting patch being arranged to form a heat-conducting element of a smoking article during the manufacture of smoking articles, the method comprising: printing longitudinally spaced apart patches of a thermally conductive printable medium onto the web of smoking article wrapper material, wherein at least some of said patches comprise an area of thermally conductive printable medium extending continuously in a longitudinal direction for at least 2 mm.
20. The method of claim 19, wherein the printing is performed by conveying the web of smoking article wrapper material to a printing cylinder and transferring the thermally conductive printable medium onto the web of smoking article wrapper material using the printing cylinder.
21. The method of claim 20, wherein the printing cylinder comprises a plurality of grooves configured to hold the thermally conductive printable medium, the grooves being arranged in a pattern corresponding to a desired pattern of patches.
22. The method of claim 19, wherein the printing comprises printing a first set of longitudinally spaced apart patches of thermally conductive printable medium onto a first side of the web of smoking article wrapper material, and printing a second set of longitudinally spaced apart patches of thermally conductive printable medium onto a second side of the web of smoking article wrapper material, the second side being opposite the first side.
23. The method of claim 22, wherein the first and second sets of longitudinally spaced apart patches are substantially aligned.
24. The method of claim 19, wherein longitudinal spacing between adjacent heat conducting patches is at least 8 mm.
25. The method of claim 19, wherein each of the heat conducting patches has a width of at least about 10 mm
26. The method of claim 19, wherein each of the heat conducting patches has a width of from about 20 mm to about 25 mm.
27. A method for manufacturing a multi-segment component for a smoking article, the method comprising: applying longitudinally spaced apart heat conducting patches onto a web of smoking article wrapper material in accordance with the method of claim 19; feeding a stream of segments of the multi-segment component along a moving delivery path; compacting the stream of segments into groups of two or more different segments, each group corresponding to a discrete multi-segment component; wrapping the segments in the web of smoking article wrapper material such that one or more heat conducting patches are provided around at least one segment of each group; and cutting the web of smoking article wrapper material between adjacent groups to separate the discrete multi-segment components.
28. The method of claim 27, wherein the two or more different segments in each group comprise a combustible carbonaceous heat source and one or more aerosol-forming substrate segments.
29. The method of claim 28, wherein the wrapping the segments in the web of smoking article wrapper material is performed such that the one or more of the heat conducting patches overlies at least part of the combustible carbonaceous heat source and at least part of the one or more aerosol-forming substrates of each group.
Description
[0130] The invention will be further described, by way of example only, with reference to the accompanying drawings in which:
[0131] FIG. 1 shows a schematic longitudinal cross-section of a smoking article according to a first example, the smoking article having a first heat-conducting element;
[0132] FIG. 2 shows a schematic longitudinal cross-section of a smoking article according to a second example, the smoking article having first and second heat-conducting elements;
[0133] FIG. 3 shows a schematic representation of a first apparatus 301 for applying heat conducting patches to a web of wrapper material according to the invention;
[0134] FIG. 4 shows a schematic representation of a second apparatus 401 for applying heat conducting patches to a web of wrapper material according to the invention;
[0135] FIG. 5 shows a schematic representation of a paper web with a first example of heat-conducting patches applied according to the invention; and
[0136] FIG. 6 shows a schematic representation of a paper web with a second example of heat-conducting patches applied according to the invention.
[0137] FIG. 1 shows a first example of a smoking article comprising a heat-conducting element manufactured according to the present invention. The smoking article 101 comprises a combustible carbonaceous heat source 103, an aerosol-forming substrate 105, an elongate expansion chamber 107 and a mouthpiece 109 in abutting coaxial alignment. The combustible heat source 103, aerosol-forming substrate 105, elongate expansion chamber 107 and mouthpiece 109 are overwrapped in an outer paper wrapper 111 of cigarette paper of low air permeability. As shown in FIG. 1, a non-combustible, gas-resistant, first barrier coating 113 is provided on substantially the entire rear face of the combustible carbonaceous heat source 103. In an alternative embodiment, a non-combustible, substantially air impermeable first barrier is provided in the form of a disc that abuts the rear face of the combustible carbonaceous heat source 103 and the front face of the aerosol-forming substrate 105. The combustible carbonaceous heat source 103 comprises a central airflow channel 115 that extends longitudinally through the combustible carbonaceous heat source 103 and the non-combustible, gas-resistant, first barrier coating 113. A gas-resistant, heat resistant, second barrier coating (not shown) is provided on the inner surface of the central airflow channel 115.
[0138] The aerosol-forming substrate 105 is located immediately downstream of the combustible heat source 103 and comprises a cylindrical plug of homogenised tobacco material 117 comprising glycerine as aerosol former and circumscribed by filter plug wrap 118. A heat-conducting element 119 surrounds and is in contact with a rear portion of the combustible heat source 103 and an abutting front portion of the aerosol-forming substrate 105. The heat-conducting element 119 conducts heat from the heat source 103 to the aerosol-forming substrate 105. As shown in FIG. 1, a rear portion of the aerosol-forming substrate 105 is not surrounded by the heat-conducting element 119.
[0139] The elongate expansion chamber 107 is located downstream of the aerosol-forming substrate 105 and comprises a cylindrical open-ended tube of cardboard 121. The mouthpiece 109 is located downstream of the expansion chamber 107 and comprises a cylindrical plug of cellulose acetate tow 123 of very low filtration efficiency circumscribed by filter plug wrap 125. The mouthpiece 109 may be circumscribed by tipping paper (not shown).
[0140] In alternative embodiments (not shown), a heat insulating element is positioned around the wrapper 111 and the heat-conducting element 119 to retain heat within the smoking article.
[0141] FIG. 2 shows a second example of a smoking article comprising a heat-conducting element manufactured according to the present invention. The smoking article 201 is substantially the same as the smoking article 101 described above in relation to FIG. 1. However, rather than having a single heat-conducting element, smoking article 201 comprises a first heat-conducting element 219 that surrounds and is in contact with a rear portion of the combustible heat source 203 and an abutting front portion of the aerosol-forming substrate 205, and a second heat-conducting element 220 that surrounds and is in contact with the wrapper 211. The second heat-conducting element 220 is positioned over the first heat-conducting element 219 and is of the same length as the first heat-conducting element 219. The second heat-conducting element 220 therefore directly overlies the first heat-conducting element 219 with the wrapper 211 between them. The first heat-conducting element 219 conducts heat from the heat source 203 to the aerosol-forming substrate 205. The second heat-conducting element 220 retains heat within the smoking article 201 to help maintain the temperature of the first heat-conducting element 219 during smoking. This in turn helps maintain the temperature of the aerosol-forming substrate 205 to facilitate continued and enhanced aerosol delivery.
[0142] In alternative embodiments (not shown), a heat insulating element is positioned around the first and the second heat-conducting elements to retain heat within the smoking article.
[0143] The method of the present invention may be used during the manufacture of the smoking articles of FIGS. 1 and 2 to form the heat-conducting elements 119, 219 and 220 on the wrapper 111, 211 by printing heat conducting patches onto a paper web.
[0144] FIG. 3 shows a schematic representation of a first apparatus 301 for the spaced application of heat conducting patches 303 to a paper web 305 according to the invention. The apparatus 301 comprises a printing unit 307, means for introducing the paper web in the form of paper input 309 and paper input drum 311, and paper output 313. The printing unit 307 comprises a printing cylinder 315, a counter roller 317, and a chamber 319. The chamber 319 has an inlet and an outlet (not shown) that connect the chamber 319 to a pressurised supply of heat-conductive printing ink and has an opening (not shown) that is sealed against the printing cylinder 315 by which the printing ink is transferred to the printing cylinder 315. The printing cylinder 315 comprises a series of grooves on its outer surface into which the ink is transferred.
[0145] Operation of the apparatus of FIG. 3 is as follows. The paper web 305 is fed to paper input drum 311 from a paper feed bobbin (not shown) and on to the printing unit 307, where it is fed between the printing cylinder 315 and the counter roller 317. As the paper travels between the printing cylinder 315 and the counter roller 317, the heat conductive ink is printed from the cylinder 315 onto the paper web 305 to form a number of spaced apart heat conducting patches 303 on one side of the paper web 305. The spacing and pattern of the patches 303 correspond to the spacing and pattern of the grooves on the printing cylinder 315. The paper web 305 then leaves the apparatus 301 at paper output 313.
[0146] FIG. 4 shows a schematic representation of a first apparatus 401 for the spaced application of heat conducting patches 403 to a paper web 405 according to the invention. The apparatus 401 comprises a printing unit 407, means for introducing the paper web in the form of paper input 409 and paper input drum 411, and paper output 413. The printing unit 407 comprises a printing cylinder 415, a counter roller 417, transfer rollers 419, pump 421, and nozzle 423. The pump 421 is connected to a supply of heat-conductive printing ink and to the nozzle 423 from which the ink is sprayed by the pump 421. The printing cylinder 415 comprises a series of grooves on its outer surface, the pattern of which corresponds to the desired pattern of patches 403 on the paper web 405. The diameter of the printing cylinder 415 may correspond to the interval between adjacent patches 403. For example, where the paper web 405 is used to make smoking articles having one printed patch 403, the diameter of the printing cylinder 415 may correspond to the length of the wrapper of each smoking article manufactured using the paper web 405.
[0147] Operation of the apparatus of FIG. 4 is as follows. The pump 421 sprays a jet of heat conductive printing ink from the nozzle 423 between a first pair of transfer rollers 419. The ink is entrained between the first pair of transfer rollers 419 and is transferred via further transfer rollers 419, creating a homogenous layer of ink. The ink is transferred by the transfer rollers 419 to the printing cylinder 415. The paper web 405 is fed to paper input drum 411 from a paper feed bobbin (not shown) and on to the printing unit 407, where it is fed between the printing cylinder 415 and the counter roller 417. As the paper travels between the printing cylinder 415 and the counter roller 417, the heat conductive ink is transferred from the cylinder 415 onto the paper web 405 to form a number of spaced apart, printed heat conducting patches 403 on one side of the paper web 405. The arrangement of the patches 403 (that is, the spacing and pattern of the patches 403) is defined by the pattern of grooves on the surface of the printing cylinder 415. The number of grooves, their surface area and depth, as well as the pressure between the printing cylinder 415 and the counter roller 417 determines the quantity of ink applied to the paper web 405 and therefore the thickness of the resulting patches 403. The paper web 405 then leaves the apparatus 401 at paper output 413.
[0148] FIG. 5 shows a schematic representation of a paper web 505 with a first example arrangement of heat-conducting patches 503 applied in accordance with the invention to form heat conducting elements 119 on smoking articles such as the smoking article shown in FIG. 1. The patches 503 form heat conducting elements in the finished smoking articles. The length 507 of each patch 503 corresponds to the desired length of each heat conducting element. The width 509 of each patch 503 corresponds to the circumference of the finished smoking article. The width 511 of the web 505 corresponds to the circumference of the finished smoking article plus a margin 513 for gluing. In alternative embodiments (not shown), the width 509′ of each patch 503′ may be equal to the width 511′ of the web 505′, whereby the width 509′ of each patch and the width 511′ of the web 505′ correspond to the circumference of the finished smoking article. The patches 503 are periodically printed on the web 505 with an even spacing 515. In smoking article manufacture, it is common to form a single length rod from one of more smoking article components wrapped in a paper web, before securing a filter mouthpiece at one end of the rod using tipping paper. The spacing 515 of the patches 503 corresponds to the spacing between heat conducting patches on adjacent rods.
[0149] FIG. 6 shows a schematic representation of a paper web 605 with a second example arrangement of heat-conducting patches 603 applied in accordance with the invention to form heat conducting elements 119 on smoking articles such as the smoking article shown in FIG. 1. The paper web 605 is substantially the same as that shown in FIG. 5. However, in FIG. 6, the patches 603 are not equally spaced on the paper web 605. In fact, there are two different spacings 615A and 615B between the patches 603. This arrangement is particularly advantageous, as will now be described. It is common in smoking article manufacture to form double length rods of components for smoking articles wrapped in a paper web. Those double length rods are then cut in two, a double length filter mouthpiece is inserted in the centre and secured with tipping paper, and then the entire double length smoking article is cut to form two smoking articles. In this arrangement, each double length rod must have the segments in one half arranged in reverse order from the segments in the other half. This is so that, when the filter mouthpiece is inserted in the centre, two correct smoking articles are produced. Thus, the patches 603 on the paper web 605 will need to have two different spacings, as shown in FIG. 6. The first spacing 615A corresponds to the spacing between patches in one double length rod. The second spacing 615B corresponds to the spacing between heat conducting patches on adjacent rods. The first and second spacings 615A and 615B are defined by the arrangement of grooves on the printing cylinder used to apply the patches 603.
[0150] Where spaced apart heat-conducting patches are required on both sides of the paper web, for example to provide a smoking article with first and second heat conducting elements as shown in FIG. 2, the paper web is conveyed to a first apparatus for the application of a first set of heat conducting patches on a first side of the paper web before being conveyed to a second apparatus for the application of a second set of patches on a second, opposite, side of the paper web. The first and second apparatuses may both be arranged to print heat-conducting patches. The first and second apparatuses for applying heat conducting patches may be substantially identical. Alternatively, one of the apparatuses may be arranged to print the heat conducting patches (see, for example, FIGS. 3 and 4), while the other apparatus is arranged to cut and glue patches of heat conductive foil onto the web, for example as described in WO-A-2009/112257.
[0151] The embodiments shown in FIGS. 1 to 6 and described above illustrate but do not limit the invention. Other embodiments of the invention may be made without departing from the scope thereof, and it is to be understood that the specific embodiments described herein are not intended to be limiting.
