An aerosol generating substrate, method and aerosol generating article thereof

Abstract

The invention relates to an aerosol generating substrate comprising cut tobacco with 15-50 cuts per inch tobacco and a filling density in the range of 200-600 mg / cc; and at least one aerosol former in an amount not less than 15 % w / w. The invention also relates to an aerosol generating article for electronically heated aerosol delivery system comprising aforesaid aerosol generating substrate.

Description

[0001]AN AEROSOL GENERATING SUBSTRATE, METHOD AND AEROSOL GENERATING ARTICLE THEREOF TECHNICAL FIELD OF THE INVENTION The present invention relates to an aerosol generating article, more particularly the present invention relates to an aerosol generating article comprising an aerosol generating substrate which has better sensorial characteristics. BACKGROUND OF THE INVENTION Electrically heated aerosol generating products are well known in the prior art. These products are commonly referred to as aerosol generating devices. Typically, such aerosol generating devices comprise an aerosol generating article made of reconstituted tobacco, a cooling segment and a mouth piece. WO2022123276A1 describes an aerosol generating material comprising cut tobacco material and cut plant material, the cut plant material having an average particle size of at least about 0.25 mm. This patent talks about aerosol generating material comprising cut tobacco and plant material wherein the cut tobacco is described as reconstituted tobacco. US20220287357A1 describes a process for the preparation of cigarette-shaped smoking products of the type to be heated and not burnt, the process comprising: adding propylene glycol to an already cut material, based on tobacco and / or cannabis in percent not less than 6% by weight on anhydrous basis of the cut material. IN 201731045712 relates to a process for preparation of an aerosol generating substrate for an aerosol generating article, wherein the process comprises the steps of: cutting reconstituted tobacco sheets into strips, specifically lower cuts per inch preferably between 15 to 30 and each strip having a length of preferably 15 mm to 45 mm, wherein said substrate for an aerosol generating article having higher densities, ranging from about 450 mg / cc to 750 mg / cc, with a draw effort below 1.5 mm W g per mm of rod. The currently available aerosol generating articles have length between 10 mm to 45 mm and circumference between 16 mm to 25 mm. Normally, 200 to 350 mg of reconstituted tobacco sheet can be filled in an aerosol generating substrate segment to achieve overall 25-30 mm water gauge pressure drop. The close association of the reconstituted tobacco particle can transfer the heat quickly. However, the same amount of cut tobacco, cannot be filled in the similar aerosol generating substrate segment without significantly increasing the pressure drop. It is found that not more than 120 mg of regular cut tobacco can be filled in 12 mm aerosol generating substrate segment to achieve the same pressure drop. The present inventors found that a tobacco column with such kind of filling inadequately transfers heat and results in subpar volume of aerosol. Hence, reconstituted cut tobacco substrate cannot be simply substituted with cut tobacco. A further disadvantage of reconstituted cut tobacco stick is its off-note smell in the side stream smoke which leads to an unpleasant sensory feel to the consumer. Another key disadvantage of conventional reconstituted cut tobacco stick is that the overall mouthful (quantity of aerosol released) per inhalation is lesser than conventional smoking articles. Accordingly, there is a need for an aerosol generating article which has better sensory attributes compared to the existing aerosol generating articles made of reconstituted tobacco. OBJECT OF THE INVENTION The primary object of the present invention is to provide an aerosol generating substrate made of cut tobacco wherein the tobacco has specific cut per inch (CPI), fill weight in the substrate and density. Another object of the present invention is to provide cut tobacco-based aerosol generating article wherein the tobacco has higher amount of aerosol former. A further object of the present invention is to provide an improved method for processing of cut tobacco, composition of cut tobacco, which results in good sensory feel. SUMMARY OF THE INVENTION The following disclosure presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key / critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later. In one aspect, the present invention provides an aerosol generating substrate comprising 150-600 mg of cut tobacco with 15-50 cuts per inch (CPI) of tobacco and having a density in the range of 200-600 mg / cc and at least one aerosol former with weight not less than 15 % w / w. In another aspect, the present invention provides a process of preparing an aerosol generating substrate to be used in an aerosol generating article, comprising steps of: a. cutting tobacco into strips of 15-50 cuts per inch (CPI); b. mixing the cut tobacco with not less than 15 % w / w of at least one aerosol former; and c. filling 150-600 mg of said cut tobacco having a density in the range of 200-600 mg / cc to form said aerosol generating substrate. In a further aspect, the present invention provides an aerosol generating article for electronically heated aerosol delivery system comprising: a. an aerosol generating substrate comprising 150-600 mg of cut tobacco with 15-50 CPI (cuts per inch of tobacco) and having a density in the range of 200-600 mg / cc and at least one aerosol former with weight not less than 15 % w / w; b. a cooling segment made of hollow cylindrical object; c. a mouth end; and d. an optional front plug. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS The above and other aspects, features and advantages of the embodiments of the present disclosure will be more apparent in the following description taken in conjunction with the accompanying drawings, in which: Figure 1 illustrates the configuration of the aerosol generating article as disclosed in the present invention. While Figure 1(a) is preferred for periphery heating, Figure 1(b) is preferred for core heating. Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may not have been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures. DETAILED DESCRIPTION OF THE PRESENT INVENTION The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding, but these are to be regarded as merely exemplary. Accordingly, those having skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for brevity. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising" used herein specify the presence of stated features, integers, steps, operations, members, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, members, components, and / or groups thereof. Also, expressions such as "at least one of," when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. The following terms defined below are within the meaning of the present invention. Cuts per inch (CPI): number of times leaf / tobacco sheet is cut in an inch (e.g. in case the sheet is 10 inches long, then 20 CPI will result in 200 strands with each strand width of around 1.2 mm). Cut tobacco or processed tobacco refers to tobacco which has been cut into fine pieces or strips. Density or Filling density refers to the amount of tobacco compacted within the substrate section of aerosol generating article. It is the mass per unit volume of substrate section. Reconstituted tobacco sheet refers to tobacco sheet made of ground tobacco particles with aerosol generating chemicals (aerosol former content), binders and natural fibers. Aerosol generating substrate is made with this sheet by pleating the sheet and gathering it to form cylindrical shape. As disclosed in the aforementioned paragraphs, aerosol generating substrates comprising reconstituted tobacco sheet transfer heat quickly owing to close association of the tobacco particles. When said substrates are heated, they give off a cellulosic off-note along with the tobacco taste, thus significantly affecting sensorial experience of the user. Described herein is an aerosol generating substrate composition comprising tobacco having in an amount greater than 120 mg in a 12 mm tobacco column that is able to maintain the desired pressure drop, adequately transfer heat and generate the desired volume of aerosol. The inventors of the present invention surprisingly found that an aerosol generating substrate comprising 15-50 cuts per inch of cut tobacco mixed with at least one aerosol former with weight not less than 15 % w / w delivers better sensory experience than conventional aerosol generating substrates made of reconstituted tobacco. Therefore, in one embodiment, the present invention relates to an aerosol generating substrate comprising 150-600 mg of cut tobacco with 15-50 cuts per inch (CPI) of tobacco and having a density in the range of 200-600 mg / cc along with at least one aerosol former with weight not less than 15 % w / w. Preferably, said substrate has a density of about 420 mg / cc. A higher volume of aerosol former acts in both increasing pliability of the cut tobacco and generating higher aerosol density. Preferably, the amount of at least one aerosol former is about 23% w / w. Aerosol former is selected from vegetable glycerin (VG), glycerine, propylene glycol (PG), ethylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, oleyl alcohol and / or a combination thereof. Cut tobacco sticks of the present invention can have a length of about 45 to about 90 mm. Preferably the length is about 54 mm. The length of cut tobacco ranges from 3.2mm to 11.5mm and width ranges from 0.051 mm to 0.17 mm. Preferably, it has a length of 6.6mm and has 30 cuts per inch (CPI). In another embodiment, the present invention relates to a process of preparing an aerosol generating substrate to be used in an aerosol generating article, comprising steps of: a. cutting tobacco into strips of 15-50 cuts per inch (CPI); b. mixing the cut tobacco with not less than 15 % w / w of at least one aerosol former; and c. filling 150-600 mg of said cut tobacco having a density in the range of 200- 600 mg / cc to form said aerosol generating substrate. In a further embodiment, the present invention relates to an aerosol generating article for electronically heated aerosol delivery system comprising: a. a segment comprising an aerosol generating substrate comprising 150- 600 mg of cut tobacco with 15-50 CPI (cuts per inch of tobacco) and having a density in the range of 200-600 mg / cc and at least one aerosol former with weight not less than 15 % w / w; b. a cooling segment made of hollow cylindrical object located downstream of the aerosol generating substrate; c. a mouth end located downstream to the cooling segment; d. an optional front plug located upstream of the aerosol generating substrate. In an exemplary embodiment, Figure 1 illustrates the aerosol generating article. While Figure 1 (a) design is preferred for periphery heating, Figure 1(b) is preferred for core heating. Both types of heating can also be incorporated in an aerosol generating article. List of Reference numerals: 1: Front plug, 2: tubular filter, 3: ventilation; 4: aerosol generating substrate; 5: acetate filter. The aerosol generating substrate of the present invention delivers better sensory experience than substrate made of reconstituted tobacco. By virtue of the present invention, more than 120 mg of cut tobacco can be filled in a 12 mm column and surprisingly said aerosol generating substrate is able to generate the desired volume of aerosol. Moreover, addition of higher aerosol former content in the cut tobacco enhances mouthful of aerosol and also improves heat transfer among the particles of cut tobacco by inducing pliability. The sensory feel of said aerosol generating substrate comprising cut tobacco stick is closest to cigarette smoke particularly in terms of taste as the property of tobacco in the cut tobacco stick is similar to the property of tobacco used in the cigarette. The aerosol generating article can be prepared with cut tobacco in the same manner as that of a combustible cigarette wherein the cut tobacco is gathered on the transfer belt of the making machine, travels through a garniture section which allows the formation of a cut tobacco-based rod and then the rod is wrapped with cigarette paper. A person skilled in the art who is capable of making combustible cigarettes can make cut tobacco-based aerosol generating substrate employing routine methods and techniques. The preparation typically involves adding aerosol former to already cut tobacco. Cutting is performed by methods known to a person skilled in the art. Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention. Examples Working example 1: Aerosol generating substrate composition (cut tobacco) Cuts per inch: 22CPI Weight: 220 mg Density : 384 mg / cc. The cut tobacco has –25-30 % vegetable glycerin Aerosol generating substrate circumference is 24.5 mm with tobacco segment length being 12 mm. Observation: Pressure drop (PD) of aerosol generating substrate was okay and the smoke mouthful (MF) was also in the desirable range of 3-4 on the scale of 5. Working example 2: Aerosol generating substrate composition (cut tobacco) Cuts per inch: 25CPI Weight: 230mg Density: 401 mg / cc and 10-15 % ventilation was made. The cut tobacco has 30 -35 % vegetable glycerin Aerosol generating substrate circumference is 24.5 mm with tobacco segment length being 12 mm. Observation: Mouthful (MF) was good and consistent for 14 inhalations and pressure drop (PD) of aerosol generating substrate was also acceptable. Non-working Example 1: Aerosol generating substrate composition: (cut tobacco). Weight: 310 mg Cuts per inch : 10CPI Density: 540 mg / cc The cut tobacco has 20 % vegetable glycerin Circumference: 24.5 mm with tobacco segment length of 12 mm. Observation: Mouthful (MF) was not consistent and pressure drop (PD) of aerosol generating substrate was unacceptable. Non-working example 2: Aerosol generating substrate composition: (cut tobacco). Weight: 260 mg Cuts per inch : 55CPI Density: 454 mg / cc Circumference : 24.5 mm with tobacco segment length of 12 mm. The cut tobacco has 20 % vegetable glycerin Observation: The pressure drop (PD) of aerosol generating substrate was unacceptable. Table 1: Sensory data Example 3 A conventional aerosol generating substrate made of reconstituted tobacco was prepared using methods such as feeding the reconstituted tobacco in the form of bobbins and then feeding the sheet obtained to a set of crimping rollers. The crimped sheets are then collated through a converging cone and formed into the rod. Alternatively, the reconstituted sheets are cut longitudinally into strips, the strips are then collated into a rod. The following sensory analysis was carried out using said conventional aerosol generating substrate and substrate as prepared according to Working Example 1. Table 2 Product generating substrates made generating substrates made of cut tobacco of reconstituted tobacco From the above table 2, it is evident that the aerosol generating substrates made of cut tobacco with more than 15% aerosol generator provides better mouthful experience with more likability for the user. It has better mouthful experience and also addresses the problem of off-note.

Claims

CLAIMS:

1. An aerosol generating substrate comprising: 150-600 mg of cut tobacco with 15-50 cuts per inch (CPI) of tobacco and a filling density in the range of 200-600 mg / cc; and at least one aerosol former in an amount not less than 15 % w / w.

2. An aerosol generating substrate as claimed in claim 1 wherein the aerosol former is selected from vegetable glycerin (VG), glycerine, propylene glycol (PG), ethylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, oleyl alcohol or a combination thereof.

3. An aerosol generating substrate as claimed in claims 1 and 2, wherein the amount of the aerosol former is about 23% w / w.

4. An aerosol generating substrate as claimed in claims 1 to 3, wherein the filling density is about 420 mg / cc.

5. A process of preparing an aerosol generating substrate to be used in an aerosol generating article, comprising steps of: cutting tobacco into strips of 15-50 cuts per inch (CPI); mixing the cut tobacco with not less than 15 % w / w of at least one aerosol former; and filling 150-600 mg of said cut tobacco having a density in the range of 200- 600 mg / cc to form said aerosol generating substrate.

6. An aerosol generating article for electronically heated aerosol delivery system comprising: a. an aerosol generating substrate comprising 150-600 mg of cut tobacco with 15-50 CPI (cuts per inch of tobacco) and having a density in the range of 200-600 mg / cc and at least one aerosol former in an amount of not less than 15 % w / w; b. a cooling segment made of hollow cylindrical object; c. a mouth end; d. an optional front plug.

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