FILTER ELEMENT, MOUTHPIECE AND COOLING ELEMENT

Abstract

There is disclosed a mouth piece, filter element or cooling element 100 comprising: a longitudinally extending core of filtering material 102; one or more channels 104 extending longitudinally from an end of the core 102; wherein the or each channel 104 has a non-circular transverse cross section which varies in the longitudinal direction by rotating about a longitudinal axis I of the mouth piece, filter element or cooling element 100.

Claims

1. A mouth piece or filter element comprising: a longitudinally extending core of filtering material; one or more channels extending longitudinally from an end of the core; wherein the or each channel has a non-circular transverse cross section which varies in the longitudinal direction by rotating about a longitudinal axis of the mouth piece or filter element.

2. The mouthpiece or filter element according to claim 1, wherein the or each channel has a transverse cross section which is a modified circle having one or more protuberant portions extending towards the centre of the circle.

3. The mouthpiece or filter element according to claim 1, wherein the or each channel has a cross shaped or rectangular transverse cross section.

4. The mouth piece or filter element according to claim 1, wherein the inner surface of the or each channel comprises one or more ridges which extend helically about a longitudinal axis of the mouth piece or filter element.

5. A mouth piece or filter element comprising: a longitudinally extending core of filtering material; and one or more channels extending longitudinally from an end of the core, wherein the or each channel has an inner surface; wherein the inner surface of the or each channel comprises one or more ridges which extend helically about a longitudinal axis of the mouth piece or filter element.

6. The mouth piece or filter element according to claim 1, wherein the or each channel is defined by the filtering material.

7. The mouth piece or filter element according to claim 1, wherein the or each channel extends along the entire length of the core.

8. The mouth piece or filter element according to claim 4, wherein the one or more ridges extend along the entire length of the inner surface of the channel.

9. The mouth piece or filter element according to claim 4, wherein the one or more ridges are integrally formed with the inner surface of the channel.

10. The mouth piece or filter element according to claim 4, wherein the inner surface of the or each channel comprises two ridges.

11. The mouth piece or filter element according to claim 1, comprising two, three or four channels.

12. The mouth piece or filter element according to claim 1, wherein the circumference of the longitudinally extending core of filtering material is from 14 mm to 25 mm.

13. The mouth piece or filter element according to claim 1, wherein the longitudinally extending core of filtering material has a total denier from 20000 to 100000 g per 9000 m.

14. The mouth piece or filter element according to claim 1, wherein the filtering material comprises cellulose acetate.

15. The mouth piece or filter element according to claim 1, wherein the filtering material comprises a plasticiser.

16. A filter, comprising a filter element according to claim 1.

17. A filter according to claim 16, comprising a further filter element joined to the first filter element.

18. A filter according to claim 17, wherein the further filter element comprises an additive.

19. A filter according to claim 16, further comprising second filter element joined to the first filter element, wherein the second filter element comprises a longitudinally extending core of smoke filtering material and a capsule fully enclosed within the core of smoke filtering material, wherein the capsule comprises a smoke modifying agent.

20. A filter according to claim 16, wherein the or each channel has a cross shaped transverse cross section.

21. A multiple rod, comprising a plurality of mouthpieces or filter elements according to claim 1 joined end-to-end in a mirror image relationship.

22. A smoking article, comprising a mouthpiece or filter element according to claim 1, the mouthpiece or filter element being joined to a rod of smokable material.

23. A cooling element, comprising a longitudinally extending core of filtering material; and one or more channels extending longitudinally from an end of the core; wherein the or each channel has a non-circular transverse cross section which varies in the longitudinal direction by rotating about a longitudinal axis of the cooling element.

24. A cooling element comprising: a longitudinally extending core of filtering material; and one or more channels extending longitudinally from an end of the core, the or each channel having an inner surface; wherein the inner surface of the or each channel comprises one or more ridges which extend helically about a longitudinal axis of the cooling element.

25. A heated aerosol generating system comprising the cooling element according to claim 23.

26. A method of making a mouthpiece, filter element or cooling element comprising: drawing filtering material through a shaping element to form a longitudinally extending core of filtering material, wherein the shaping element comprises one or more rotating rods having a non-circular transverse cross section, the or each rotating rod forming one or more channels within the core of filtering material, wherein the or each channel has a transverse cross section that varies in the longitudinal direction by rotating about a longitudinal axis of the mouth piece, filter element or cooling element.

27. The method according to claim 26, wherein the or each rod comprises one or more grooves which form one or more ridges on the inner surface of the or each channel, the one or more ridges extending helically about a longitudinal axis of the mouth piece, filter element or cooling element.

28. A method according to claim 26, wherein the filtering material comprises a plasticiser.

29. A method according to claim 26, wherein heat is applied to the filtering material as it passes through the shaping element.

30. The mouth piece or filter element according to claim 5, wherein the or each channel is defined by the filtering material.

31. The mouth piece or filter element according to claim 5, wherein the or each channel extends along the entire length of the core.

32. The mouth piece or filter element according to claim 5, wherein the one or more ridges extend along the entire length of the inner surface of the channel.

33. The mouth piece or filter element according to claim 5, wherein the one or more ridges are integrally formed with the inner surface of the channel.

34. The mouth piece or filter element according to claim 5, wherein the inner surface of the or each channel comprises two ridges.

35. The mouth piece or filter element according to claim 5, comprising two, three or four channels.

36. The mouth piece or filter element according to claim 5, wherein the circumference of the longitudinally extending core of filtering material is from 14 mm to 25 mm.

37. The mouth piece or filter element according to claim 5, wherein the longitudinally extending core of filtering material has a total denier from 20000 to 100000 g per 9000 m.

38. The mouth piece or filter element according to claim 5, wherein the filtering material comprises cellulose acetate.

39. The mouth piece or filter element according to claim 5, wherein the filtering material comprises a plasticiser.

40. A filter, comprising a filter element according to claim 5.

41. A filter according to claim 40, comprising a further filter element joined to the first filter element.

42. A filter according to claim 41, wherein the further filter element comprises an additive.

43. A filter according to claim 40, comprising a first filter element according to claim 5 and a second filter element joined to the first filter element, wherein the second filter element comprises a longitudinally extending core of smoke filtering material and a capsule fully enclosed within the core of smoke filtering material, wherein the capsule comprises a smoke modifying agent.

44. A filter according to claim 40, wherein the or each channel has a cross shaped transverse cross section.

45. A multiple rod, comprising a plurality of mouthpieces or filter elements according to claim 5 joined end-to-end in a mirror image relationship.

46. A smoking article, comprising a filter according to claim 16, the filter being joined to a rod of smokable material.

47. A smoking article, comprising a mouthpiece or filter element according to claim 5, the mouthpiece or filter element being joined to a rod of smokable material.

48. A smoking article, comprising a filter according to claim 40, the filter being joined to a rod of smokable material.

Description

[0109] Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0110] FIG. 1 is an end view of a mouthpiece, filter element or cooling element according to the present invention.

[0111] FIG. 2 is a perspective view of a mouthpiece, filter element or cooling element according to the present invention.

[0112] FIG. 3 is a side view of a mouthpiece, filter element or cooling element according to the present invention.

[0113] FIG. 4 is a sectional view of the mouthpiece, filter element or cooling element shown in FIG. 3.

[0114] FIG. 5 is a sectional view of a mouthpiece, filter element or cooling element shown in FIG. 3.

[0115] FIG. 6 is sectional end view of a mouthpiece, filter element or cooling element according to the invention.

[0116] FIG. 7 is an end view of a mouthpiece, filter element or cooling element according to the invention.

[0117] FIG. 8 is a sectional view of a mouthpiece, filter element or cooling element according to the invention.

[0118] FIG. 9 is an end view of a mouthpiece, filter element or cooling element according to the invention.

[0119] FIG. 10 is a sectional view of a mouthpiece, filter element or cooling element according to the invention.

[0120] FIG. 11 is a sectional view of a mouthpiece, filter element or cooling element according to the invention.

[0121] FIG. 12 is a sectional view of a mouthpiece, filter element or cooling element according to the invention.

[0122] FIG. 13 is a perspective view of a multi-segment filter according to the invention.

[0123] FIG. 1 shows an end view of the mouthpiece, filter element or cooling element according to an embodiment of the present invention. The mouthpiece, filter element or cooling element 100 comprises a longitudinally extending core of filtering material 102. The core of filtering material is substantially cylindrical (as illustrated in FIG. 2). The core of filtering material comprises cellulose acetate tow comprising triacetin as a plasticiser in an amount of 18% by weight of the filtering material and plasticiser. The cellulose acetate tow has a filament denier of 7.3 g per 1000 m and a total denier of 36000 g per 1000 m (7.3Y36). The mouthpiece, filter element or cooling element 100 also includes a channel 104 which extends from an end of the core 102 longitudinally through the core 102. The channel 104 is defined by the filtering material which forms the core 102. The channel is surrounded by filtering material. As illustrated in FIGS. 1 and 2, the channel 104 is positioned centrally with respect to the core 102 and is substantially cylindrical. The mouth piece or filter element has a circumference of 23.4 mm.

[0124] As shown in FIG. 2, the mouth piece, filter element or cooling element includes an outer surface 106 which defines the longitudinally extending core 102. As shown in FIG. 2, the core 102 extends along the longitudinal axis (I). The longitudinally extending core 102 includes an inner surface 108 which defines the channel 104. The channel 104 extends along the longitudinal axis I of the core 102. The distance between the outer surface 106 and the inner surface 108 is known as the wall thickness and is 1.2 mm. As shown in FIG. 1, the inner surface 108 includes two ridges 110 which extend helically about the longitudinal axis (I) of the mouth piece, filter element or cooling element. The ridges 110 extend along the inner surface 108 of the channel 104, and the ridges 110 protrude from the inner surface 108 of the channel 104. The two ridges 110 are integral with the inner surface 108 and are defined by the filtering material that makes up the core 102.

[0125] FIG. 3 shows a side view of the filter element, mouthpiece or cooling element along the plane defined by the y and I axis shown in FIG. 2.

[0126] FIG. 4 shows a sectional view of the mouthpiece, filter element or cooling element along line A-A, as shown in FIG. 2. The channel transverse cross section shown in FIG. 4 includes a modified circle having two diametrically opposed protuberant parts which extend from the edge of the circle towards the centre of the circle. The diametrically opposed protuberant parts correspond to the ridges 110 which extend helically about the longitudinal axis of the mouth piece, filter element or cooling element. It will be appreciated that the irregular transverse cross section of the mouth piece and filter elements of the present invention may be useful in combatting counterfeiting. As shown in FIG. 4, the transverse cross section of the channel 104 is rotated with respect to the channel cross section shown at the end of the filter element 100 as shown in FIG. 2.

[0127] The ridges 110 extend helically with respect to the longitudinal axis (I) of the mouth piece, filter element or cooling element, so the position of the ridge with respect to the circumference of the channel varies along the length of the filter element, mouthpiece or cooling element. Such a non-uniform transverse cross section along the length of the filter element or mouth piece provides further anti-counterfeiting properties.

[0128] FIG. 5 shows a further sectional view of the mouthpiece, filter element or cooling element along line B-B as shown in FIG. 3. As is shown in FIG. 5, the transverse cross section of the channel 104 is rotated with respect to both the transverse cross section shown in FIG. 4 and the end cross section shown in FIG. 2.

[0129] FIG. 6 shows a sectional view of a further filter element or mouth piece 200 according to the present invention. The filter element or mouthpiece 200 shown in FIG. 6 is similar to that shown in FIGS. 4 and 5, but includes four ridges 210 extending along the inner surface of the channel 204 helically about the longitudinal axis of the mouth piece, filter element or cooling element.

[0130] FIG. 7 shows an end view and FIG. 8 shows a sectional view of a further filter element, mouthpiece or cooling element 300 according to the present invention. The filter element, mouthpiece or cooling element 300 shown in FIGS. 7 and 8 is similar to that shown in FIGS. 1 to 6, but the filter element, mouthpiece or cooling element 300 shown in FIGS. 7 and 8 has a channel 304 having a rectangular transverse cross section. The transverse cross section of the channel varies in the longitudinal direction of the core by rotating about a longitudinal axis of the mouth piece, filter element or cooling element.

[0131] FIG. 9 shows an end view and FIG. 10 shows a sectional view of a further filter element, mouth piece or cooling element 400 according to the present invention. The filter element, mouthpiece or cooling element 400 shown in FIG. 10 is similar to that shown in FIGS. 1 to 8, but the filter element, mouthpiece or cooling element 400 shown in FIGS. 9 and 10 has a channel 404 having a cross shaped transverse cross section. The transverse cross section of the channel varies in the longitudinal direction of the core by rotating about a longitudinal axis of the mouth piece, filter element or cooling element.

[0132] FIG. 11 shows a sectional view of a further filter element, mouth piece or cooling element 500 according to the present invention. The filter element, mouth piece or cooling element 500 shown in FIG. 11 is similar to those shown in FIGS. 1 to 5, but includes two channels 504a and 504b. Each channel 504a, 504b includes ridges 510a and 510b which extend helically about a longitudinal axis of the mouth piece, filter element or cooling element.

[0133] FIG. 12 shows a sectional view of a further filter element, mouth piece or cooling element 600 according to the present invention. The filter element, mouth piece or cooling element 600 shown in FIG. 12 is similar to those shown in FIGS. 1 to 5, but includes three channels 604a, 604b and 604c. Each channel 604a, 604b, 604c includes ridges 610a, 610b and 610c which extend helically about a longitudinal axis of the mouth piece, filter element or cooling element.

[0134] Any of the mouthpieces or filter elements illustrated in FIGS. 1 to 12 may form part of a multi segment filter which is included in a smoking article such as a cigarette. Some smoking articles, such as those containing marijuana, include a mouthpiece as described herein and do not include further filter elements such as those included in a multi-segment filter.

[0135] During use, smoke travels through the mouthpiece or filter element, and the smoke takes a helical path within the channel which means that smoke emerging from the mouthpiece or filter element will continues to follow a helical path, for example in the mouth of the user. The helical path taken by the smoke affects the mouthfeel of the smoke, as described in further detail in the examples that are set out below.

[0136] The cooling element may form part of a heated aerosol generating system which may form part of a non-combustible product, such a heated tobacco product. A heated aerosol generating system typically includes a heating element, a power source, a rod of tobacco, one or more cooling elements and a mouthpiece. The cooling element described herein may be incorporated into the heated aerosol generating system between the mouthpiece and the tobacco rod. During use, the heating element heats the rod of tobacco to form an aerosol. The aerosol then passes into the cooling element and is cooled by the cooling element. Due to the configuration of the channel, the aerosol takes a helically path through the cooling element which reduces the temperature of the aerosol.

[0137] The filter elements, mouthpieces and cooling elements shown in FIGS. 1 to 12 may be made by the following process.

[0138] Continuously advancing plasticised tow is drawn into a shaping element. The shaping element includes a substantially cylindrical chamber in which a rod (mandrel) protrudes.

[0139] The shape of the rod determines the cross sectional shape of the channel. For example, the rod used to make the mouthpiece, filter element or cooling element shown in FIGS. 1 to 5 is a cylinder which includes two diametrically opposed grooves which extend along the length of the cylindrical rod. The rod used to make the mouthpiece, filter element or cooling element shown in FIG. 6 is a cylinder having two pairs of diametrically opposed grooves. The rod used to make the mouth piece, filter element or cooling element shown in FIGS. 7 and 8 has a rectangular cross section, and the rod used to form the mouthpiece, filter element or cooling element shown in FIGS. 9 and 10 has a cross shaped cross section.

[0140] In the case of a mouthpiece, filter element or cooling element as shown in FIG. 11, the shaping element includes two protruding mandrels. In the case of a mouthpiece, filter element or cooling element as shown in FIG. 12, the shaping element includes three protruding mandrels.

[0141] The chamber also includes steam inlets for enabling superheated steam to pass into the chamber. The rod is connected to an external motor which causes the rod to rotate.

[0142] As the plasticised tow advances into the chamber, the tow is shaped into a longitudinally extending cylindrical core by the internal walls of the chamber. The chamber acts as a die. While the tow is being shaped by the internal walls of the chamber, the tow is forced around the rod, such that a channel is formed within the core, the channel being defined by the filtering material. The channel shape is defined by the rod as explained above. Rotation of the rod, as the filtering material passes through the chamber, forms a longitudinally extending channel in which the channel cross section varies in the longitudinal direction by rotating about the central longitudinal axis of the channel. In the case of a rod which includes grooves, such as used to make the mouthpiece, filter element or cooling element shown in FIGS. 1 to 6, the grooves in the rod define ridges on the inner surface of the channel. The rotation of the rod and consequently the rotation of the grooves causes ridges to form on the inner surface of the channel, the ridges extend along the inner surface of the channel and follow a helical path about the longitudinal axis of the channel. It is possible to vary the helical pitch of the ridges by controlling the rotational speed of the rod and the speed at which the tow is drawn through the chamber. The depth and width of each ridge may be modified by varying the depth and width of each groove in the rod. If additional ridges are desired, then the rod may include additional grooves. For example, the mouth piece, filter element or cooling element shown in FIG. 6 makes use of a rod having four grooves.

[0143] In the case of a cross shaped rod, the rod forms a channel having a cross shaped cross section. As the rod rotates, a substantially cylindrical channel is formed within the core and the triangular gap between adjacent prongs of the cross shaped rod form ridges on the inner surface of the channel.

[0144] In the case of a rod having a rectangular cross section, rotation of the rod means that the cross section of the channel will vary in the longitudinal direction by rotation along the longitudinal length of the core.

[0145] The diameter of the channel at its widest point may be varied by changing the diameter of the rod at its widest point. Similarly, the diameter of the core of filtering material may be varied by modifying the diameter of the cylindrical chamber. If a channel is desired which does not include ridges extending along its entire length, then the rod can be modified to include grooves which do not extend along the entire length of the rod.

[0146] Superheated steam enters the chamber via the inlet and heats the plasticised tow. The action of heat acts to cure the plasticised tow and thereby hardens the filtering material, such that it retains its shape after leaving the shaping element.

[0147] The filtering material exits the shaping element in the form of a substantially cylindrical longitudinally extending core, which includes a longitudinally extending channel within the core. In the case of a rod which includes two grooves, the channel includes two ridges which extend helically along the inner surface of channel about the longitudinal axis of the channel.

[0148] The tow may be plasticised as part of the above process before the tow enters the shaping element, for example the continually advancing tow may be sprayed with plasticiser at a plasticising station positioned before the shaping element. Alternatively, the plasticiser may be pre-applied to the tow in a separate process.

[0149] The substantially cylindrical longitudinally extending core may be further treated with steam and then cooled by a series of air jets and the substantially cylindrical longitudinally extending core is cut to form a series of individual filter elements, mouth pieces or cooling elements.

[0150] FIG. 13 shows a multi-segment filter 700 which includes a filter element 400 which is similar to that shown in FIGS. 9 and 10. The filter element 400 includes a longitudinally extending core of filtering material 402. The core is substantially cylindrical as shown in FIG. 13. The filter element 400 also includes a channel 404 which extends from an end of the core 402 longitudinally along the entire length of the core 402. The channel 404 is defined by the filtering material which forms the core 402, and the channel is surrounded by filtering material. The channel 404 is positioned centrally with respect to the core 402. The channel 404 has a substantially cross shaped transverse cross section. As is shown in the cutaway view portion of FIG. 13, the transverse cross section of the channel 404 varies in the longitudinal direction by rotating about a longitudinal axis of the filter element 400.

[0151] As is shown in the cutaway portion of FIG. 13, the channel includes four ridges 410 which extend helically about the longitudinal axis of the filter element 400.

[0152] The multi-segment filter 700 also includes a second filter element 710. The second filter element 710 includes a longitudinally extending core of filtering material 720. As is shown in the second cutaway portion of FIG. 13, the second filter element 710 includes a capsule 740 which is fully enclosed within the core of filtering material 720. The capsule may be a frangible capsule containing a smoke modifying agent such as a flavourant. It will be appreciated that other additives may be included in the core. The second filter element 710 is wrapped with a first plug wrap 750 and the first filter element 400 and second filter element 710 are together wrapped with a second plug wrap 760 which functions to hold the first filter element and the wrapped second filter element together.

[0153] The second filter element may be made according to standard methods known in the art. The first filter element and second filter element may be joined and wrapped using standard manufacturing methods known in the art.

EXAMPLES

Example 1

[0154] Four filtered cigarettes including a filter element according to the present invention were prepared along with four control filtered cigarettes. The filtered cigarettes according to the present invention were prepared based on a standard commercially available Kretec (clove flavoured) tobacco cigarette. The standard 27 mm mono cellulose acetate filter was removed from the cigarette and replaced with a multi-segment filter according to the present invention. The multi-segment filter of the present invention included a 20 mm section of the removed standard mono cellulose acetate filter joined to a filter element of the present invention which was 7 mm in length.

[0155] The control cigarettes included a multi-segment filter including a 20 mm mono cellulose acetate filter joined to a 7 mm standard tube filter.

[0156] The filtered cigarettes were smoked by four users. The users reported that compared to the control cigarette, the filtered cigarettes which included filter elements of the present invention produced tobacco smoke which had a spicier taste, and was more evenly dispersed in the mouth. The users reported that the control cigarettes, which included a standard tube filter element, produced smoke which was concentrated on the tongue.

Example 2

[0157] Filtered cigarettes were assembled which included a single filter element as shown in FIG. 1. Further filtered cigarettes were assembled which included a single filter element as shown in FIGS. 7 and 8.

[0158] Filtered cigarettes were assembled which included a single standard tube filter element which included a channel having a continuous transverse cross section.

[0159] Each type of filtered cigarette were tested by smoking under standard conditions and the total nicotine free dry particulate matter (NFDPM) yield was measured (according to standards ISOIS017025, IS03308, IS04387).

[0160] The applicant found that the cigarettes which included the filter elements of the invention had a lower NFDPM yield than the cigarettes that included a single standard tube filter element.

Example 3

[0161] Filtered cigarettes were assembled. The filtered cigarettes included a multi-segment filter including a single 7 mm standard tube filter element joined to a 20 mm mono-acetate filter. The standard tube filter included a channel having a continuous transverse cross section. The multi-segment filter was joined to a tobacco rod. Further filtered cigarettes were assembled and included a multi-segment filter including either filter element A, B or C. Each of filter element A, B or C was 7 mm in length.

[0162] Filter element A is a single filter element as shown in FIGS. 1-5.

[0163] Filter element B is a single filter element as shown in FIGS. 7 and 8.

[0164] Filter element C is a single filter element as shown in FIGS. 9 and 10.

[0165] Total particulate matter (TPM) was measured for each of the tested filter elements. Total particulate matter in the mainstream smoke exiting the filter was measured by performing a smoking test under standard conditions using the method according to ISO 4387. Total particulate matter collected by the filter is measured using gravimetric analysis. The filter is also extracted using isopropanol and the extracted mixture analysed using gas chromatography coupled to a flame ionization detector (GC-FID) to determine the amount of nicotine. This analysis was carried out according to standard ISO10315. The extracted mixture was also analysed using gas chromatography coupled to a thermal conductivity detector (GC-TCD) to determine the amount of water. This analysis was carried out according to standard ISO10362.

[0166] The amount of Nicotine free dry particulate matter NFDPM (tar) is calculated by the following formula:

NFDPM=TPM−Nicotine−Water (mg/cig)

[0167] Tar and nicotine retention were calculated according to the following equations:

[00003]$\mathrm{Nicotine}\mathrm{Retention}\left(\%\right)=\frac{\mathrm{Nicotine}\mathrm{in}\mathrm{filter}\left(\mathrm{mg}\right)}{\mathrm{Nicotine}\mathrm{in}\mathrm{mainstream}\mathrm{smoke}+\mathrm{Nicotine}\mathrm{in}\mathrm{filter}\left(\mathrm{mg}\right)}\times 100\%$$\mathrm{NFDPM}\mathrm{Retention}\left(\%\right)=\frac{\mathrm{NFDPM}\mathrm{in}\mathrm{filter}\left(\mathrm{mg}\right)}{\mathrm{NFDPM}\mathrm{in}\mathrm{mainstream}\mathrm{smoke}+\mathrm{NFDPM}\mathrm{in}\mathrm{filter}\left(\mathrm{mg}\right)}\times 100\%$

[0168] The amount of nicotine in the filter following smoking was measured according to the methods set out above. The amount of NFDPM in the filter following smoking was calculated as set out above.

[0169] The results of the NFDPM retention and Nicotine retention are summarised in table 1 below.

TABLE-US-00001 TABLE 2 NFDPM Nicotine retention retention Filter % % Standard tube filter element 32 34 Filter element A 36.5 32.5 Filter element B 39.5 36 Filter element C 36 34

[0170] As shown in table 1 above, the filters of the present invention (including Filter elements A, B and C) exhibited much higher NFDPM retention as compared to the standard tube filter. Additionally with the exception of filer element A, the filter elements of the invention demonstrated similar or higher nicotine retention compared to the standard tube filter.

Example 4

[0171] A cooling element according to the invention was prepared. The cooling element had a configuration as illustrated in FIGS. 1-5 and as described above. The cooling element had a length of 18 mm and a circumference of 22.53 mm.

[0172] A comparative cooling element having a length of 18 mm was also formed from crimped polylactic acid (PLA) filter material.

[0173] The cooling element according to the invention and the comparative cooling element were each assembled into separate tobacco heated product devices and the devices were smoked using a linear smoking machine under conditions according to standard ISO20778.

[0174] The amount of hydroquinone, resorcinol and catechol in the vapour exiting the device was measured using high performance liquid chromatography (HPLC) with fluorescence detection (FLD).

[0175] The results from these tests are set out in table 2 below.

TABLE-US-00002 TABLE 2 Comparative Cooling cooling Parameter element A element Puffs 12 12 Hydroquinone/μg 2.53 4.03 Resorcinol/μg 0.77 0.90 Catechol/μg 4.67 11.09

[0176] As illustrated in table 2, the cooling element of the invention significantly reduced the quantities of hydroquinone, resorcinol and catechol present in the vapour exiting the device.