AEROSOL-GENERATING ARTICLE HAVING WRAPPER COMPRISING AN EMBOSSED PORTION

Abstract

An aerosol-generating article is provided, including: a rod of aerosol-generating substrate; and a paper wrapper wrapped around at least a portion of the aerosol-generating article, the paper wrapper including an embossed portion circumscribing the rod of aerosol-generating substrate along at least 80 percent of the length of the rod and having a basis weight of from 50 grams per square meter to 100 grams per square meter. A method of producing an aerosol-generating article is also provided.

Claims

1.-15. (canceled)

16. An aerosol-generating article, comprising: a rod of aerosol-generating substrate; and a paper wrapper wrapped around at least a portion of the aerosol-generating article, the paper wrapper comprising an embossed portion circumscribing the rod of aerosol-generating substrate along at least 80 percent of the length of the rod and having a basis weight of from 50 grams per square meter to 100 grams per square meter.

17. The aerosol-generating article according to claim 16, wherein the paper wrapper has a basis weight of from 60 grams per square meter to 70 grams per square meter.

18. The aerosol-generating article according to claim 16, wherein the paper wrapper has a basis weight of from 75 grams per square meter to 80 grams per square meter.

19. The aerosol-generating article according to claim 16, wherein at least the embossed portion of the paper wrapper is a water-resistant wrapper.

20. The aerosol-generating article according to claim 16, further comprising: a plurality of segments assembled together longitudinally, the plurality of segments including the rod of aerosol-generating substrate, wherein the paper wrapper is wrapped around the rod of aerosol-forming substrate and at least one other of the plurality of segments; and a layer of adhesive on an inner surface of the paper wrapper, the layer of adhesive circumscribing at least two of the plurality of segments to thereby keep the at least two segments in place relative to each other.

21. The aerosol-generating article according to claim 20, wherein the layer of adhesive covers at least 50 percent of an area of the inner surface of the paper wrapper.

22. The aerosol-generating article according to claim 21, wherein the layer of adhesive on the inner surface of the paper wrapper has a mass of from 15 milligrams to 45 milligrams.

23. The aerosol-generating article according to claim 21, wherein the layer of adhesive on the inner surface of the paper wrapper has a mass of from 25 milligrams to 35 milligrams.

24. The aerosol-generating article according to claim 16, wherein the rod of aerosol-generating substrate comprises an aerosol former having a glycerine content of at least about 10 percent by weight.

25. The aerosol-generating article according to claim 16, wherein the embossed portion of the paper wrapper directly circumscribes the rod of aerosol-generating substrate.

26. The aerosol-generating article according to claim 16, wherein the embossed portion of the paper wrapper circumscribes the rod of aerosol-generating substrate along at least 90 percent of a length of the rod.

27. The aerosol-generating article according to claim 16, wherein the embossed portion of the paper wrapper circumscribes the rod of aerosol-generating substrate along 100 percent of a length of the rod.

28. The aerosol-generating article according to claim 16, wherein the embossed portion of the paper wrapper has a bending moment of from 3 centinewton centimeters to 8 centinewton centimeters at 90 degrees.

29. The aerosol-generating article according to claim 16, wherein the embossed portion of the paper wrapper has a bending moment of from 4 centinewton centimeters to 7 centinewton centimeters at 90 degrees.

30. The aerosol-generating article according to claim 16, wherein the embossed portion of the paper wrapper has a bending moment of from 5 centinewton centimeters to 6 centinewton centimeters at 90 degrees.

31. The aerosol-generating article according to claim 16, wherein the rod of aerosol-generating substrate comprises a gel composition.

32. The aerosol-generating article according to claim 16, further comprising an elongate susceptor element extending in a longitudinal direction through the rod of aerosol-generating substrate.

33. The aerosol-generating article according to claim 16, further comprising an upstream element provided upstream of the rod of aerosol-generating substrate and abutting an upstream end of the rod of aerosol-generating substrate.

34. The aerosol-generating article according to claim 16, further comprising a downstream section arranged downstream of the rod of aerosol-generating substrate and in axial alignment with the rod of aerosol-generating substrate, the downstream section comprising one or more downstream elements.

35. A method of producing an aerosol-generating article, the method comprising: providing a rod of aerosol-generating substrate; providing a paper wrapper having a basis weight of from 50 grams per square meter to 100 grams per square meter; embossing a portion of the paper wrapper; and wrapping the paper wrapper around the aerosol-generating article, such that the embossed portion circumscribes at least the rod of aerosol-generating substrate along at least percent of a length of the rod.

Description

[0272] FIG. 1 shows a schematic side sectional view of an aerosol-generating article in accordance with a first embodiment of the invention;

[0273] FIG. 2 shows a schematic side sectional view of an aerosol-generating article in accordance with a second embodiment of the invention;

[0274] FIG. 3 shows a schematic side sectional view of an aerosol-generating article in accordance with a third embodiment of the invention;

[0275] FIG. 4 shows an aerial view of a pattern of embossments on an embossed portion of a wrapper to be used with an aerosol-generating article of an embodiment of the invention;

[0276] FIG. 5 shows a schematic side sectional view of a pattern of embossments on an embossed portion of a wrapper to be used with an aerosol-generating article of an embodiment of the invention;

[0277] FIG. 6 shows a schematic side sectional view of a double stick for forming an aerosol-generating article of an embodiment of the invention;

[0278] FIG. 7 shows a plan view of a first exemplary wrapper;

[0279] FIG. 8 shows a plan view of a second exemplary wrapper; and

[0280] FIG. 9 shows a schematic side sectional view of an aerosol-generating article in accordance with a fourth embodiment of the invention.

[0281] Embodiments of the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which:

[0282] FIG. 1 shows an aerosol-generating article 1 in accordance with a first embodiment of the invention. The aerosol-generating article 1 comprises a rod 111 of aerosol-generating substrate 112 and a downstream section 114 at a location downstream of the rod 111 of aerosol-generating substrate 112. Further, the aerosol-generating article 1 comprises an upstream section 16 at a location upstream of the rod 111 of aerosol-generating substrate 112. Thus, the aerosol-generating article 1 extends from an upstream or distal end 18 to a downstream or mouth end 20.

[0283] The aerosol-generating article has an overall length of about 45 millimetres.

[0284] The downstream section 114 comprises a tubular element 100 located immediately downstream of the rod 111 of aerosol-generating substrate 112, the tubular element 100 being in longitudinal alignment with the rod 111 of aerosol-generating substrate 112. In the embodiment of FIG. 1, the upstream end of the tubular element 100 abuts the downstream end of the rod 111 of aerosol-generating substrate 12 and in particular the downstream end of the rod 111.

[0285] The rod 111 comprises an aerosol-generating substrate 112 comprising a porous medium loaded with a gel composition as defined above. An example of a suitable gel composition is shown below in Table 1:

TABLE-US-00001 TABLE 1 Gel composition Component Amount (% by weight) Water 20 Glycerol 73.5 Nicotine 1.5 Gelling agent 3 Lactic acid 1 Divalent cations 1

[0286] In addition, the downstream section 114 comprises a mouthpiece element 42 at a location downstream of the tubular element 100. In more detail, the mouthpiece element 42 is positioned immediately downstream of the tubular element 100. As shown in FIG. 1, an upstream end of the mouthpiece element 42 abuts the downstream end 40 of the tubular element 100.

[0287] The mouthpiece element 42 is provided in the form of a cylindrical plug of low-density cellulose acetate. The mouthpiece element 42 has a length of about 12 millimetres and an external diameter of about 7.25 millimetres. The RTD of the mouthpiece element 42 is about 12 millimetres H2O.

[0288] The aerosol-generating article 1 comprises a ventilation zone 60 provided at a location along the tubular element 100. In more detail, the ventilation zone is provided at about 4 millimetres from the downstream end of the tubular element 100. A ventilation level of the aerosol-generating article 1 is about 40 percent.

[0289] The rod 111 comprises an aerosol-generating substrate 112 of one of the types described above. The aerosol-generating substrate 112 may substantially define the structure and dimensions of the rod 111. The rod 111 comprising the aerosol-generating substrate has an external diameter of about 7.25 millimetres and a length of about 12 millimetres.

[0290] The aerosol-generating article 1 further comprises a high basis weight wrapper 10 with an embossed portion 113 circumscribing the rod 111 of aerosol-generating substrate 112. In the embodiment of FIG. 1, the embossed portion 113 of the high basis weight wrapper 10 fully circumscribes the rod 111 of aerosol-generating substrate around the circumference of the rod 111. In this embodiment, the embossed portion 113 of the high basis weight wrapper circumscribes the rod 111 of aerosol-generating substrate along the full length of the rod 111.

[0291] In this embodiment, the high basis weight wrapper 10 extends along the full length of the aerosol-generating article 1, from an upstream end 18 to a downstream end 20. The high basis weight wrapper 10 fully circumscribes the upstream element 46, the rod 111 of aerosol-generating substrate 112, the tubular element 100 and the mouthpiece 42 around their circumferences. The high basis weight wrapper 10 defines an outer surface of the aerosol-generating article 1.

[0292] The high basis weight wrapper 10 further comprises a layer of adhesive 115 on the inner surface of the wrapper 10. The representation of the layer of adhesive 115 in FIG. 1 is for schematic purposes only and therefore does not show the layer of adhesive itself or its arrangement on the wrapper. The layer of adhesive 115 will be described in more detail below with respect to FIGS. 7 and 8. In the embodiment of FIG. 1, the high basis weight wrapper with the layer of adhesive 115 fully circumscribes the aerosol-generating article, and the adhesive is in direct contact with the aerosol-generating article.

[0293] The representation of the embossed portion 113 in FIG. 1 is for schematic purposes only and therefore does not show the embossments themselves or their arrangement on the embossed portion 113. The embossed portion 113 will be described in more detail below with respect to FIGS. 4 and 5.

[0294] The rod 111 of aerosol-generating substrate 112 also comprises an elongate susceptor element 44 within the aerosol-generating substrate 112. In more detail, the susceptor element 44 is arranged substantially longitudinally within the aerosol-generating substrate 112, such as to be approximately parallel to the longitudinal direction of the rod 111. As shown in the drawing of FIG. 1, the susceptor element 44 is positioned in a radially central position within the rod and extends effectively along the longitudinal axis of the rod 111.

[0295] The susceptor element 44 extends all the way from an upstream end to a downstream end of the rod 111. In effect, the susceptor element 44 has substantially the same length as the rod 111 comprising the aerosol-generating substrate 112.

[0296] In the embodiment of FIG. 1, the susceptor element 44 is provided in the form of a strip and has a length of about 12 millimetres, a thickness of about 60 micrometres, and a width of about 4 millimetres.

[0297] The upstream section 16 comprises an upstream element 46 located immediately upstream of the rod 111 of aerosol-generating substrate 112, the upstream element 46 being in longitudinal alignment with the rod 111 of aerosol-generating substrate 112. In the embodiment of FIG. 1, the downstream end of the upstream element 46 abuts the upstream end of the rod 111 and in particular the upstream end of the aerosol-generating substrate 112. This advantageously prevents the susceptor element 44 from being dislodged. Further, this ensures that the consumer cannot accidentally contact the heated susceptor element 44 after use.

[0298] The upstream element 46 is provided in the form of a cylindrical plug of cellulose acetate circumscribed by a stiff wrapper 10. The upstream element 46 has a length of about 5 millimetres. The RTD of the upstream element 46 is about 30 millimetres H2O.

[0299] The tubular element 100 comprises a tubular body 103 defining a cavity 106 extending from a first end 101 of the tubular body 103 to a second end 102 of the tubular body 103. The tubular element 100 also comprises a folded end portion forming a first end wall 104 at the first end 101 of the tubular body 103. The first end wall 104 delimits and opening 105, which permits airflow between the cavity 106 and the exterior of the tubular element 100. In particular, the embodiment of FIG. 1 is configured so that aerosol may flow from the rod 111 of aerosol-generating substrate 112 through the opening 105 into the cavity 106.

[0300] The cavity 106 of the tubular body 103 is substantially empty, and so substantially unrestricted airflow is enabled along the cavity 106. Consequently, the RTD of the tubular element 100 can be localised at a specific longitudinal position of the tubular element 100namely, at the first end wall 104and can be controlled through the chosen configuration of the first end wall 104 and its corresponding opening 105. In the embodiment of FIG. 1, the RTD of the tubular element 100 (which is essentially the RTD of the first end wall 104) is substantially 10 millimetres H2O. In the embodiment of FIG. 1, the tubular element 100 has a length of about 16 millimetres, an external diameter of about 7.25 millimetres, and an internal diameter (D.sub.FTS) of about 6.5 millimetres. Thus, a thickness of a peripheral wall of the tubular body 103 is about 0.75 millimetres.

[0301] As shown in FIG. 1, the first end wall 104 extends substantially transverse to the longitudinal direction of the aerosol generating article 1 and the longitudinal direction of the tubular element 100. The opening 105 is the only opening in the first end wall 104 and the opening 105 is positioned in a generally radially central position of the tubular element 100. Consequently, the first end wall 104 is generally annular shaped.

[0302] The combination of the first end wall 104 and its corresponding opening 105 provide an effective barrier arrangement which may restrict movement of the aerosol-generating substrate, whilst also enabling one or both of air and aerosol to flow from the rod 111 of aerosol-generating substrate 112 and through the opening 105 into the cavity 106. The opening 105 is generally aligned with the radially central position of the susceptor element 44 of the rod 111 of aerosol-generating substrate 112. This may be advantageous as it helps to keep a distance between the first end wall 105 and the susceptor, and thus mitigate undesirable heating of the first end wall 105. This may also be advantageous as it can provide direct unimpeded downstream flow of aerosol produced by the portion of the aerosol-generating substrate in close proximity to the susceptor element 44.

[0303] The first end wall 104 is formed by folding an end portion of the tubular element 100 about a fold point. The fold point generally corresponds to the first end of the tubular body 103 of the tubular element 100.

[0304] FIG. 2 shows an aerosol-generating article 2 in accordance with a second embodiment of the invention. The aerosol-generating article 2 has similarities with the aerosol-generating article 1 of the first embodiment of the invention in FIG. 1, and like-for-like reference numerals are used where appropriate. However, the aerosol-generating article 2 of FIG. 2 does not comprise a tubular element. In particular, in contrast to the aerosol-generating article 1 of FIG. 1, the aerosol-generating article 2 of FIG. 2 does not comprise a tubular element 100 between the rod 211 of aerosol-generating substrate 212 and the mouthpiece element 42. Instead, the aerosol-generating article 2 of FIG. 2 comprises two hollow acetate tubes between the rod 211 of aerosol-generating substrate 212 and the mouthpiece element 42. These are a first hollow acetate tube 280 located immediately downstream of, and in longitudinal alignment with a rod 211 of aerosol-generating substrate 212 and a second hollow acetate tube 290 located immediately downstream of the first hollow acetate tube 280.

[0305] The first hollow acetate tube 280 and the second hollow acetate tube 290 define a tubular body 203 with a cavity 206 extending from a first upstream end 201 of the tubular body 203 to a second downstream end 202 of the tubular body 203.

[0306] The first hollow acetate tube 280 defines a support element. The first upstream end of the first hollow acetate tube abuts the downstream end of the rod 211 of aerosol-generating substrate 212.

[0307] The second hollow acetate tube 290 defines an aerosol-cooling element which abuts the downstream end of the first hollow acetate tube 280.

[0308] The internal cavity 206 of the tubular body 203 defined by the first hollow acetate tube 280 and the second hollow acetate tube 290 is substantially empty, and so substantially unrestricted airflow is enabled along the cavity 206.

[0309] As a whole, the tubular body 203 does not substantially contribute to the overall RTD of the aerosol-generating article. An RTD of the tubular body 203 as a whole is substantially 0 millimetres H2O.

[0310] The first hollow acetate tube 280 has a length of about 8 millimetres, an external diameter of about 7.25 millimetres, and an internal diameter (D.sub.FTS) of about 1.9 millimetres. Thus, a thickness of a peripheral wall of the first hollow acetate tube 280 is about 2.67 millimetres.

[0311] The second hollow acetate tube 290 has a length of about 8 millimetres, an external diameter of about 7.25 millimetres, and an internal diameter (D.sub.STS) of about 3.25 millimetres. Thus, a thickness of a peripheral wall of the second hollow acetate tube 290 is about 2 millimetres. Thus, a ratio between the internal diameter (D.sub.FTS) of the first hollow acetate tube 280 and the internal diameter (D.sub.STS) of the second hollow acetate tube 290 is about 0.75.

[0312] The aerosol-generating article 2 comprises a ventilation zone 60 provided at a location along the second hollow acetate tube 290. In more detail, the ventilation zone is provided at about 2 millimetres from the upstream end of the second hollow acetate tube 290. A ventilation level of the aerosol-generating article 2 is about 25 percent.

[0313] The aerosol-generating article 2 may further comprise a high basis weight wrapper 10 with an embossed portion 13 circumscribing the rod 211 of aerosol-generating substrate 212. In this embodiment of FIG. 1, the embossed portion 213 of the high basis weight wrapper 10 fully circumscribes the rod 211 of aerosol-generating substrate 212 around the circumference of the rod 211. In this embodiment, the embossed portion 213 of the high basis weight wrapper 10 circumscribes the rod 211 of aerosol-generating substrate 212 along only a portion of the length of the rod 211.

[0314] In this embodiment, the high basis weight wrapper 10 extends along the full length of the aerosol-generating article 2, from an upstream end 18 to a downstream end 20. The high basis weight wrapper 10 fully circumscribes the upstream element 46, the rod 211 of aerosol-generating substrate 212, the first hollow acetate tube 280, the second hollow acetate tube 290 and the mouthpiece 42 around their circumferences. The high basis weight wrapper 10 defines an outer surface of the aerosol-generating article 2.

[0315] The representation of the embossed portion 213 in FIG. 2 is for schematic purposes only and therefore does not show the embossments themselves or their arrangement on the embossed portion 213. The embossed portion 213 will be described in more detail below with respect to FIGS. 4 and 5.

[0316] FIG. 3 shows an aerosol-generating article 3 in accordance with a third embodiment of the invention. Unlike the embodiments of FIGS. 1 and 2, the aerosol-generating article 3 of the third embodiment does not comprise any form of upstream element 46 upstream of a rod 311 of aerosol-generating substrate 312. Consequently, the upstream or distal end 318 of the aerosol-generating article 3 is defined by the rod 311 of aerosol-generating substrate 312. Furthermore, in the third embodiment of the invention the rod 311 of aerosol-generating substrate 312 does not comprise a susceptor element 44 located within the aerosol-generating substrate 312. Such an aerosol-generating article 3 may therefore be one which is configured to receive a heater blade of an aerosol-generating device. The heater blade may be inserted into the aerosol-generating substrate 312 through the upstream end 318 of the aerosol-generating article 3.

[0317] The aerosol-generating article 3 of the third embodiment has a hollow acetate tube 380 substantially the same as the first hollow acetate tube 280 of the aerosol-generating article 2 of the second embodiment. This hollow acetate tube 380 defines a support element and has a cavity 306 extending from an upstream end of the of the hollow acetate tube 380 to a downstream end of the hollow acetate tube 380.

[0318] The cavity 306 of the hollow acetate tube 380 is substantially empty, and so substantially unrestricted airflow is enabled along the cavity 306.

[0319] The hollow acetate tube 380 does not substantially contribute to the overall RTD of the aerosol-generating article. An RTD of the intermediate hollow section 250 as a whole is substantially 0 millimetres H2O.

[0320] The aerosol-generating article 3 of the third embodiment comprises an aerosol-cooling element 370 located immediately downstream of the hollow acetate tube 380, the aerosol-cooling element 370 being in longitudinal alignment with the rod 311 of aerosol-generating substrate 312 and the hollow acetate tube 380. In more detail, the upstream end of the aerosol-cooling element 370 abuts the downstream end of the hollow acetate tube 380.

[0321] In contrast to the aerosol cooling element (hollow acetate tube 290) of the aerosol-generating device 2 of the second embodiment, the aerosol-cooling element 370 comprises a plurality of longitudinally extending channels which offer a low or substantially null resistance to the passage of air through the rod. In more detail, the aerosol-cooling element 370 is formed from a preferably non-porous sheet material selected from the group comprising a metallic foil, a polymeric sheet, and a substantially non-porous paper or cardboard. In particular, in the embodiment illustrated in FIG. 3, the aerosol-cooling element 370 is provided in the form of a crimped and gathered sheet of polylactic acid (PLA). The aerosol-cooling element 370 has a length of about 8 millimetres, and an external diameter of about 7.25 millimetres.

[0322] The aerosol-generating article 3 may further comprise a high basis weight wrapper 10 with an embossed portion 313 circumscribing the rod 311 of aerosol-generating substrate 312. In this embodiment of FIG. 3, the embossed portion 313 of the high basis weight wrapper circumscribes the rod 311 of aerosol-generating substrate around only a portion of the circumference of the rod 311. In this embodiment, the embossed portion 313 of the high basis weight wrapper 10 circumscribes the rod 311 of aerosol-generating substrate along the full length of the aerosol-generating article 3.

[0323] In this embodiment, the high basis weight paper wrapper 10 extends along the full length of the aerosol-generating article 3, from an upstream end 18 to a downstream end 20. The paper wrapper 10 fully circumscribes the rod 311 of aerosol-generating substrate 312, the hollow acetate tube 380, the aerosol-cooling element 370 and the mouthpiece 42 around their circumferences. The high basis weight paper wrapper 10 defines an outer surface of the aerosol-generating article 3.

[0324] The representation of the embossed portion 313 in FIG. 3 is for schematic purposes only and therefore does not show the embossments themselves or their arrangement on the embossed portion 313. The embossed portion 313 will be described in more detail below with respect to FIGS. 4 and 5.

[0325] FIGS. 4 and 5 respectively show an aerial view and a side sectional view of a pattern of embossments on an embossed portion of a wrapper 410 to be used with an aerosol-generating article of an embodiment of the invention. The embossed portion 13 shown in both FIGS. 4 and 5 is in an unwrapped state. The embossed portion 13 has a plurality of embossments 4 spaced apart in a repeating pattern. Debossments 5 are defined by the space between each embossment where the high basis weight wrapper 10 has not been embossed. Each embossment is a spherical dome. The embossed portion 13 is further defined by the pitch 6 of the embossments 4. This pitch 6 is defined by the distance between the centres of two adjacent embossments 4. An embossment 4 is also defined by its depth 7. The depth 7 of an embossment is equal to the thickness of the unembossed high basis weight wrapper 10 plus the height of the protrusion of an embossment 4. Each embossment has substantially the same depth, pitch and profile. The embossed portion 13 has an inner surface 401 which when assembled is in direct or indirect contact with an aerosol-generating article. It is the debossments 5 that are in direct or indirect contact with the aerosol-generating article. The inner surface of the embossments 4 are spaced away from the aerosol-generating article. The embossed portion also has an outer surface 402. The embossed portion of the wrapper 410 comprises a layer of adhesive 415 on the inner surface 401 of the wrapper 410.

[0326] Experimental tests were carried out by the inventors to test the manufacturing capabilities of different aerosol-generating article wrappers, including aerosol-generating article wrappers in accordance with the present invention. These tests were aimed at determining the aerosol-generating article manufacturing speeds that could be achieved with wrappers having different properties. The tests focused primarily on comparing conventional wrappers for aerosol-generating articles known in the art with higher basis weight wrappers. However, other parameters of the wrappers were assessed throughout the tests.

[0327] The wrappers tested were paper wrappers in the form of rectangular sheets of paper with an inner surface and an outer surface. The wrappers tested had two transverse edges in the direction of rolling of the wrapper and two longitudinal edges in a direction perpendicular to the direction of rolling of the wrapper. The wrapper was wrapped around the entire circumference of the aerosol-generating article. The width of the wrappers tested was greater than the circumference of the aerosol-generating articles such that the two longitudinal edges of the wrappers overlapped when the wrappers were wrapped around the articles.

[0328] During the manufacturing process tested, each wrapper was wrapped around two identical portions of two separate aerosol-generating articles which were joined together. The two portions of aerosol-generating article remained joined together for the tested manufacturing process. The two portions of aerosol-generating article, once wrapped in the wrapper, are known as a double stick. As illustrated by FIG. 6, the exemplary double stick 6 under test comprises: two identical aerosol cooling elements 670 (each one at a respective extremity of the stick); two identical intermediate hollow tubular sections 603, each one adjacent to, and abutting each aerosol cooling element 670; and, one rod of aerosol-generating substrate 611 in a central portion of the stick abutted by the two intermediate hollow sections 603. All of these segments are wrapped in a wrapper 610, which extends along the entire length of the double stick 600. For the purposes of the experimental tests, properties of the wrapper 610 were varied, as discussed in more detail below. As seen illustrated by FIG. 6, each intermediate hollow tubular section 603 is formed by a first hollow acetate tube and a second hollow acetate tube of the type described above in respect of FIG. 2.

[0329] The two joined portions of the double stick can be separated from one another in a further manufacturing process in which the double stick is cut in half along cut line 675, through the rod of aerosol-generating substrate. Each resulting portion of aerosol-generating article has a mouthpiece element, an intermediate hollow section and a shorter rod of aerosol-generating substrate. The experimental tests described herein focus the production speed of double sticks achieved for each wrapper tested. All parameters from the experimental data relate to a double stick. In other words, the mass of glue and the manufacturing speeds refer respectively to the mass of glue used for a double stick and the number of double sticks produced per minute.

[0330] A number of other parameters for the wrapper were varied to assess their effects on manufacturing speeds. These other parameters included the embossment or not of the wrapper along its entire surface and the amount of glue applied to the inner surface of the wrapper. The wrappers tested had either 5, 15 or 30 milligrams of glue per wrapper.

[0331] As illustrated by FIG. 7, in the test samples with 5 milligrams of glue per wrapper 710, the 5 milligrams of glue is applied as a single longitudinal strip 795. The strip of glue occupies a very small percentage of the inner surface of the wrapper 710, and extends along substantially the entire length of the wrapper 710. When the wrapper 710 is wrapped around the segments of the article, the strip 795 resides between with overlapping edges of the wrapper 710 to form a longitudinal seam. The rest of the inner surface of the wrapper in FIG. 7 is substantially free of glue.

[0332] As illustrated by FIG. 8, in the test samples with 15 or 30 milligrams of glue per wrapper, the glue was applied in an even layer across substantially the entire inner surface of the wrapper 810. In particular, the glue was provided in two discrete portions 891, 892 occupying substantially the entire inner surface of the wrapper 810. The only adhesive-free portions of the wrapper 810 were a peripheral border extending around all edges of the wrapper 893 and a strip of adhesive-free region 894, separating the two discrete portions 891, 892 of adhesive.

[0333] During the testing of the double sticks, minor defects, such as partial opening of the wrapper at the overlap, were classified as acceptable as they do not appreciably affect the manufacturing process. Defects classified as not acceptable were ones found to appreciably affect manufacturing of the double sticks. For example, if the opening at the overlap of the wrapper is too large, the machine can become jammed or glue can escape the wrapper and contaminate machinery.

[0334] The manufacturing speed shown in Tables 2 and 3 refer to the number of double sticks produced to a good quality with little to no defects. The tests also included an assessment of the defects present on the double sticks when the production speeds were 500 double sticks per minute higher than the highest acceptable production speed that yielded good quality double sticks. It should be noted that the manufacturing apparatus used to conduct the tests had an inherent maximum manufacturing speed of 5000 double sticks per minute.

TABLE-US-00002 TABLE 2 Comparison of the manufacturing speeds of wrappers having different parameters Basis weight Glue Manufacturing Test of the paper (milligrams speed achieved sample (grams per Embossed per double (double sticks No. square meter) (Y/N) stick) per minute) 1 45 N 5 4500 2 78 N 5 0 3 78 N 15 1500 4 78 Y 15 2500 5 78 Y 30 4000

[0335] In a first experiment, for which the results are summarised in Table 2, a double stick with a conventional wrapper for an aerosol-generating article was compared with double sticks having higher grammage wrappers with a basis weight of 78 grams per square meter.

[0336] Test sample 1 had a conventional wrapper with a basis weight of 45 grams per square meter with no embossing and 5 milligrams of glue per article. Test sample 1 achieved a manufacturing speed of 4500 double sticks per minute although there was not a significant increase in the number of defects observed when the speed was increased to 5000 double sticks per minute.

[0337] Test sample 2 had a high grammage wrapper, with a high basis weight of 78 grams per square meter with no embossing and 5 milligrams of glue per article. Test sample 2 did not achieve any good quality double sticks at any speed of manufacturing. With the higher basis weight paper used for this test, the wrapper did not adhere to itself at its overlapping portion resulting in an unusable product. This was due to high bending moment required to roll the wrapper and the high spring back effect of the wrapper once rolled. This test sample highlighted the need to modify the higher basis weight wrapper in some way to overcome the high bending moment required to roll the wrapper and the high spring back effect of the wrapper once rolled.

[0338] Test sample 3 had an identical wrapper to Test sample 2 with the exception of 15 milligrams of glue being applied instead of 5 milligrams, and the glue being applied evenly across substantially the entire inner surface of the wrapper, as illustrated by FIG. 8. In this configuration, the machine speed achieved manufacturing speeds of 1500 good quality double sticks per minute. This test sample clearly shows that the increased quantity of glue and the increased area of application has a positive effect on the manufacturing speeds achieved. When the manufacturing speed was increased by 500 double sticks per minute, the double sticks of Test Sample 3 exhibited defects that would be sufficient to have a discernible effect on finished aerosol-generating articles.

[0339] Test sample 4 had an identical wrapper to that of Test sample 3 with the exception of the wrapper of Test sample 4 being an embossed wrapper. This test sample achieved manufacturing speeds of 2500 good quality double sticks per minute. This test sample clearly shows that the embossment of the wrapper has a positive effect on the manufacturing speeds that can be achieved. Even when manufacturing speeds were increased by 500 double sticks per minute, only minor defects were observed, with such minor defects not being considered sufficient to have a discernible effect on the finished aerosol-generating articles.

[0340] Test sample 5 had an identical wrapper to that of Test sample 4 with the exception that: for the wrapper of Test sample 5, the amount of glue applied to the inner surface of the wrapper was further increased to 30 milligrams per wrapper. A further increase in the manufacturing speeds achieved was observed, up to 4000 good quality double sticks per minute. Even when manufacturing speeds were increased by 500 double sticks per minute, only minor defects were observed, with such minor defects not being considered sufficient to have a discernible effect on the finished aerosol-generating articles.

[0341] Four further test samples, not shown in Table 2 were tested. These four further samples all had paper wrappers with a basis weight of 45 grams per square meter. Two of these four further test samples had an embossed wrapper, one with 15 milligrams of glue per double stick, the other with 30 milligrams of glue per double stick. The paper wrappers of the remaining two further test samples were not embossed, and one had 15 milligrams of glue per double stick, whilst the other had 30 milligrams of glue per double stick. All of the four further test samples achieved the maximum manufacturing speed of the machine of 5000 double sticks per minute with little to no defects.

[0342] The data collected in Table 2 clearly shows the positive effect on the manufacturing speed and quality of the double sticks resulting from both: a) the increase in glue applied to the inner surface of a higher basis weight wrapper; and b) the embossing of the wrapper. It was noted that the most common double stick defect observed was the unsticking of the wrapper around the central rod of aerosol-generating substrate. This could be explained by the fact that the aerosol-generating substrate is a softer material than the mouthpiece sections and the intermediate hollow sections of the double sticks. More specifically, the aerosol-generating substrate provides a lower resistance than the other components to the rolling pressure applied during the rolling of the wrapper around these components. As a result, the wrapper requires a higher force to be applied to assemble the wrapper around the substrate. Consequently, the embossing of the wrapper and increased amount of glue are particularly effective when these circumscribe the rod of aerosol-generating substrate.

TABLE-US-00003 TABLE 3 Comparison of the manufacturing speeds of 65 grams per square meter wrappers having different parameters Basis weight Glue Manufacturing Test of the paper (milligrams speed achieved sample (grams per Embossed per double (double sticks No. square meter) (Y/N) stick) per minute) 1 45 N 5 4500 6 65 N 15 1500 7 65 Y 15 2500 8 65 N 30 3000 9 65 Y 30 4000

[0343] In a second experiment, Test Sample 1 was compared with further test samples 6 to 9, each of which had a paper wrapper with a basis weight of 65 grams per square meter. The results of the second experiment are shown in Table 3.

[0344] Test sample 6 had an unembossed high grammage wrapper with a basis weight of 65 grams per square meter and 15 milligrams of glue applied to an inner surface. Test samples with this configuration achieved manufacturing speeds of 1500 good quality double sticks per minute. With a slight increase in speed of 500 double sticks per minute, significant defects were observed in the double sticks, rendering them unusable.

[0345] Test sample 7 had an identical wrapper to that of Test sample 6 with the exception of the wrapper of Test sample 7 being an embossed wrapper. This resulted in an increase in the manufacturing speeds up to 2500 good quality double sticks per minute. With this configuration, when the manufacturing speeds were increased by 500 double sticks per minute, only minor defects were observed that did not affect the manufacturing process. Once again, this highlights the advantageous manufacturing effect resulting from embossing the high basis weight wrapper.

[0346] The wrapper of Test sample 8 was the same as that of Test sample 6 with the exception of the amount of glue being applied to the inner surface of the wrapper being increased to 30 milligrams per square meter. Test sample 8 achieved manufacturing speeds of 3000 good quality double sticks per minute. When the manufacturing speeds were increased by 500 double sticks per minute, only minor defects were observed that did not affect the manufacturing process. This further shows the advantageous effects of the increasing the amount of glue applied to the inner surface of the wrapper and how this can have a beneficial effect on the manufacturing of high basis weight wrappers.

[0347] The wrapper of Test sample 9 was the same as that of Test sample 8 with the exception of the wrapper of Test sample 9 being an embossed wrapper. In this configuration manufacturing speeds of 4000 good quality double sticks per minute were achieved. When the manufacturing speeds were increased by 500 double sticks per minute, only very minor defects were observed in the double sticks and these did not negatively impact manufacturing.

[0348] It is clear from the data shown in Tables 2 and 3 that both the embossment of a wrapper and the application of a high amount of glue to substantially the entire inner surface of the wrapper have advantageous effects on the manufacturing speeds that can be achieved for a high basis weight wrapper.

[0349] The combination of an embossed wrapper and a high amount of glue achieved the best results for both grammages of wrapper tested. This combination of parameters most closely match the manufacturing speeds seen with a conventional wrapper with the added benefits of the higher basis weight wrapper as discussed in more detail above.

[0350] FIG. 9 shows a schematic side sectional view of an aerosol-generating article 9 in accordance with a fourth embodiment of the invention. The aerosol-generating article 9 has similarities with the aerosol-generating article 2 of the second embodiment of the invention in FIG. 2. For brevity, duplicated features from the embodiment of FIG. 2 will not be repeated.

[0351] In this embodiment, the wrapper 910 circumscribes the upstream element 46, the rod 911 of aerosol-generating substrate 912, and the tubular body 903 defined by a first hollow acetate tube 980 and a second hollow acetate tube 990. The wrapper 910 does not circumscribe the mouthpiece element 42.

[0352] In the embodiment of FIG. 9, the aerosol-generating article comprises a high basis weight wrapper 910 with an embossed portion 913 circumscribing the rod 911 of aerosol-generating substrate 912. In this embodiment, the embossed portion 913 of the high basis weight wrapper 910 fully circumscribes the rod 911 of aerosol-generating substrate 912 around the circumference of the rod 911. In this embodiment, the embossed portion 913 of the high basis weight wrapper 910 circumscribes the rod 911 of aerosol-generating substrate 912 along the full length of the rod.

[0353] The aerosol-generating article 9 further comprises a tipping wrapper 919 circumscribing the mouthpiece element 42 and the second hollow acetate tube 990. The tipping wrapper 919 is wrapped around the mouthpiece element 42 and an outer surface of a portion of the wrapper 910 circumscribing the second hollow acetate tube.