AEROSOL-FORMING SUBSTRATE IN THE FORM OF SOLID UNITARY BODY FORM TWO PARTICULATE MATERIALS

Abstract

An aerosol-forming substrate is provided for an aerosol generating system, the aerosol-forming substrate including: a first particulate material; and a second particulate material, the first particulate material being formed from particles having a D50 size of between 2 micrometres and 20 micrometres, and the second particulate material being formed from particles having a D50 size of between 50 micrometres and 80 micrometres, the aerosol-forming substrate being a solid unitary body. An aerosol generating article including the aerosol-forming substrate, and a process for manufacturing the aerosol-forming substrate, are also provided.

Claims

1.-15. (canceled)

16. An aerosol-forming substrate for an aerosol generating system, the aerosol-forming substrate comprising: a first particulate material; and a second particulate material, the first particulate material being formed from particles having a D50 size of between 2 micrometres and 20 micrometres, and the second particulate material being formed from particles having a D50 size of between 50 micrometres and 80 micrometres, wherein the aerosol-forming substrate is a solid unitary body.

17. The aerosol-forming substrate according to claim 16, wherein a ratio of a mass of the first particulate material to a mass of the second particulate material in the aerosol-forming substrate is no more than 1:2.

18. The aerosol-forming substrate according to claim 16, wherein the first particulate material is formed from particles having a D50 size of 10 micrometres, and the second particulate material is formed from particles having a D50 size of 59 micrometres.

19. The aerosol-forming substrate according to claim 16, wherein the first particulate material is formed from particles having a D95 size of between 10 micrometres and 60 micrometres, and the second particulate material is formed from particles having a D95 size of between 80 micrometres and 130 micrometres.

20. The aerosol-forming substrate according to claim 19, wherein the first particulate material is formed from particles having a D95 size of 33 micrometres, and the second particulate material is formed from particles having a D95 size of 116 micrometres.

21. The aerosol-forming substrate according to claim 16, wherein the first particulate material is formed from particles having a diameter of between 5 micrometres and 40 micrometres, and the second particulate material is formed from particles having a diameter of between 50 micrometres and 250 micrometres.

22. The aerosol-forming substrate according to claim 16, wherein the first particulate material and the second particulate material are formed from the same material.

23. The aerosol-forming substrate according to claim 16, wherein at least one of the first particulate material and the second particulate material comprise one or more of cellulose and microcrystalline cellulose (MCC).

24. The aerosol-forming substrate according to claim 16, further comprising a binder.

25. The aerosol-forming substrate according to claim 16, further comprising one or more of nicotine, lactic acid, and sucrose.

26. The aerosol-forming substrate according to claim 16, further comprising cellulose strengthening fibres, wherein the cellulose strengthening fibres have a D50 size of between 0.8 millimetres and 1.5 millimetres.

27. The aerosol-forming substrate according to claim 16, wherein a ratio of a mass of the first particulate material to a mass of the second particulate material in the aerosol-forming substrate is at least 1:5.

28. The aerosol-forming substrate according to claim 16, wherein the aerosol-forming substrate does not comprise tobacco.

29. An aerosol generating article comprising an aerosol-forming substrate according to claim 16.

30. A process for manufacturing an aerosol-forming substrate, the process comprising: providing a first particulate material, the first particulate material being formed from particles having a D50 size of between 2 micrometres and 20 micrometres; providing a second particulate material, the second particulate material being formed from particles having a D50 size of between 50 micrometres and 80 micrometres; mixing the first particulate material and the second particulate in an aqueous solution to form a slurry; casting the slurry; and drying the cast slurry to form a solid substrate.

Description

[0219] Examples will now be further described with reference to the figure in which:

[0220] FIG. 1 illustrates an example of an aerosol generating article containing the aerosol-forming substrate as described herein;

[0221] FIG. 2 is a plot of glycerol delivery per puff as a function of puff number for a three of aerosol generating articles each containing a different aerosol-forming substrate;

[0222] FIG. 3 is a plot of nicotine delivery per puff as a function of puff number for a three of aerosol generating articles each containing a different aerosol-forming substrate; and

[0223] FIG. 4 is an illustrative plot of the particle size distribution of an aerosol-forming substrate according to the present invention.

[0224] FIG. 1 illustrates an example of an aerosol generating article 1000 containing an aerosol-forming substrate as described herein.

[0225] In the example of FIG. 1, the aerosol generating article 1000 includes four elements: the aerosol-forming substrate 1020, a hollow cellulose acetate tube 1030, a spacer element 1040, and a mouthpiece filter 1050. The four elements 1020, 1030, 1040, 1050 are arranged sequentially and in a coaxial alignment. The four elements 1020, 1030, 1040, 1050 are assembled by a cigarette paper 1060 to form the aerosol generating article 1000.

[0226] In the example of FIG. 1, the aerosol generating article 1000 has a mouth-end 1012 and a distal end 1013. A user may insert the mouth-end 1012 into their mouth during use. The distal end 1013 is located at the opposite end of the aerosol generating article 1000 to the mouth end 1012. The example of an aerosol generating article 1000 illustrated in FIG. 1 is particularly suitable for use with an electrically-operated aerosol generating device comprising a heater for heating the aerosol-forming substrate.

[0227] In one example, when assembled, the aerosol generating article 1000 is about 45 millimetres in length and has an outer diameter of about 7.2 millimetres and an inner diameter of about 6.9 millimetres.

[0228] In the example of FIG. 1, the aerosol-forming substrate 1020 is provided in the form of a plug made by crimping a sheet of aerosol-forming substrate. The sheet is gathered, crimped and wrapped in a filter paper (not shown) to form the plug.

[0229] The aerosol-forming substrate 1020 comprises a first particulate material and a second particulate material. The first particulate material is formed from particles having a D50 size of about 10 micrometres and a D95 size of about 33 micrometres. The second particulate material is formed from particles having a D50 size of about 59 micrometres and a D95 size of about 116 micrometres.

[0230] The first particulate material is formed from particles having a diameter of between 5 micrometres and 40 micrometres, and the second particulate material is formed from particles having a diameter of between 50 micrometres and 250 micrometres.

[0231] The ratio of the mass of the first particulate material to the mass of the second particulate material in the aerosol-forming substrate is about 1:2.

[0232] The first and second particulate materials are formed from microcrystalline cellulose (MCC).

[0233] The first particulate material has a density greater than 1.0 grams per centimetre cubed. The second particulate material has a density of between 0.5 grams per centimetre cubed and 1.0 grams per centimetre cubed.

[0234] The aerosol-forming substrate 1020 comprises about 15 weight percent of the first particulate material.

[0235] The aerosol-forming substrate 1020 comprises about 30 weight percent of the second particulate material.

[0236] The aerosol-forming substrate 1020 further comprises about 30 weight percent glycerine as an aerosol former.

[0237] The aerosol-forming substrate 1020 further comprises about 5 weight percent carboxymethyl cellulose as a binder.

[0238] The aerosol-forming substrate 1020 further comprises about 6 weight percent cellulose strengthening fibres.

[0239] The aerosol-forming substrate 1020 further comprises about 1.5 weight percent nicotine.

[0240] The aerosol-forming substrate 1020 further comprises about 2.5 weight percent lactic acid.

[0241] The aerosol-forming substrate 1020 further comprises about 2.5 weight percent sucrose.

[0242] An aerosol generating article 1000 as illustrated in FIG. 1 is designed to engage with an aerosol generating device in order to be consumed. Such an aerosol generating device includes means for heating the aerosol-forming substrate 1020 to a sufficient temperature to form an aerosol. Typically, the aerosol generating device may comprise a heating element that surrounds the aerosol generating article 1000 adjacent to the aerosol-forming substrate 1020, or a heating element that is inserted into the aerosol-forming substrate 1020.

[0243] Once engaged with an aerosol generating device, a user draws on the mouth-end 1012 of the smoking article 1000 and the aerosol-forming substrate 1020 is heated to a temperature of about 260 degrees Celsius. At this temperature, volatile compounds are evolved from the aerosol-forming substrate 1020. These compounds condense to form an aerosol. The aerosol is drawn through the filter 1050 and into the user's mouth.

[0244] FIG. 2 shows the result of a study to determine the delivery of glycerol per puff as a function of the puff number for three aerosol generating articles each containing a different aerosol-forming substrate.

[0245] The first aerosol-forming substrate is a reference substrate which was a heat stick for use with an IQOS heating device manufactured by Philip Morris Products. The reference substrate comprises cast leaf tobacco. The line corresponding to the first aerosol-forming substrate is identified as 2003.

[0246] The second aerosol-forming substrate comprises about 13.3 weight percent of the first particulate material and about 26.7 weight percent of the second particulate material. Accordingly, in the second aerosol-forming substrate, the ratio of the mass of the first (smaller) particulate material to the mass of the second (larger) particulate material in the aerosol-forming substrate is about 1:2. The line corresponding to the second aerosol-forming substrate is identified as 2004. The second aerosol-forming substrate is in accordance with the present invention.

[0247] The third aerosol-forming substrate comprises about 40 weight percent of the second (larger) particulate material. The third aerosol-forming substrate does not comprise any amount of the first (smaller) particulate material. The line corresponding to the third aerosol-forming substrate is identified as 2005.

[0248] The glycerol yield in micrograms per puff is plotted on the vertical axis, identified as 2001. The puff number is plotted on the horizontal axis, identified as 2002.

[0249] As can be seen from the graph shown in FIG. 2, it was found that the delivery of glycerol was advantageously sustained over the full 12 puffs in the second aerosol-forming substrate 2004 according to the present invention. Indeed, it was advantageously demonstrated that the second aerosol-forming substrate 2004 according to the present invention exhibited greater glycerol yield even than the first reference aerosol-forming substrate 2003.

[0250] By contrast, the third aerosol-forming substrate 2005 which does not contain a mixture of the first and second particulate material exhibits significantly lower delivery of glycerol over the 12 puffs.

[0251] The test also demonstrated that providing a ratio of the mass of the first (smaller) particulate material to the mass of the second (larger) particulate material in the aerosol-forming substrate of about 1:2 results is favourable glycerol delivery.

[0252] FIG. 3 shows the result of a study to determine the delivery of nicotine per puff as a function of the puff number for the same three aerosol generating articles each containing the same aerosol-forming substrates described above in reference to FIG. 2.

[0253] The first aerosol-forming substrate, which is a reference substrate, is identified as 3003.

[0254] The second aerosol-forming substrate, which is according to the present invention, is identified as 3004.

[0255] The third aerosol-forming substrate, which does not contain a mixture of the first and second particulate material, is identified as 3005.

[0256] The nicotine yield in micrograms per puff is plotted on the vertical axis, identified as 3001. The puff number is plotted on the horizontal axis, identified as 3002.

[0257] As can be seen from the graph shown in FIG. 3, it was found that the delivery of nicotine was advantageously sustained over the full 12 puffs in the second aerosol-forming substrate 3004 according to the present invention when compared to the third aerosol-forming substrate 3005, which does not contain a mixture of the first and second particulate material.

[0258] FIG. 4 is an illustrative plot of the particle size distribution of an aerosol-forming substrate according to the present invention. The graph shown in FIG. 4 is for illustrative purposes only and is not based on actual data. Particle size is plotted on the horizontal axis, identified as 4001. The frequency of a given particle size is plotted on the vertical axis, identified as 4002.

[0259] As can be seen from FIG. 4, the particle size distribution of an aerosol-forming substrate according to the present invention exhibits a bimodal distribution pattern. The lower peak corresponds to the first (smaller) particulate material. From the lower peak, the D50.sub.1 figure for the first particulate material may be determined and is identified on the graph. The D95.sub.1 figure for the first particulate material is also identified on the graph. From the higher peak, the D50.sub.2 figure for the second particulate material may be determined and is identified on the graph. The D95.sub.2 figure for the second particulate material is also identified on the graph.

[0260] The ratio of the mass of the first (smaller) particulate material to the mass of the second (larger) particulate material in the aerosol-forming substrate is about 1:2. This is demonstrated in the distribution on FIG. 4 since the peak corresponding to the second particulate material is approximately twice as high as the first peak corresponding to the first particulate material.