DESC:Field of the invention
The present invention relates to aerosol generating substrate, more particularly the present invention relates to heat not burn tobacco product which has similar nicotine delivery, flavour and draw effect as that of conventional cigarettes. Further the present invention provides a method of preparing the same.

Background and prior art
Alternate devices for delivery nicotine such as electronic vaping devices and e-cigarettes have not been able to meet consumer satisfaction. One possible reason can be their inability to deliver the required tobacco taste/flavour to consumer as that by a conventional cigarette. Some of the existing electronic and/or carbon heat not burn products heat tobacco substrate to generate aerosol for meeting consumer requirements.
Unlike combustion in a conventional cigarette, heat not burn products only releases nicotine and flavour without burning/consuming the tobacco rod. Heating a conventional cigarette rod at temperatures of around 350 to 450°C will not provide the same deliveries as that by a conventional process of combustion. Thus, it would be highly desirable to come up with alternate material that can release required nicotine by heating.
There are few prior arts which address few of the stated problems however with significant shortcomings.
EP 3075266 by Gudang Garam Tbk. relates to a method of producing aerosol generating article using reconstituted tobacco material, wherein the recon sheet is cut into shreds and continuous rods with density between 100 to 400 mg/cc are produced. However, to deliver nicotine similar to that of a conventional cigarette from this material, obtained using conventional cutting process, the length of the tobacco rod has to be more than 20 mm which creates problems of disposal post consumption. Also making rods at densities higher than 400 mg/cc poses huge challenges in filling, end quality, draw effort, etc.
WO 2013178766 discloses a rod for an aerosol-generating article comprises at least two sheets (2, 3) of tobacco material gathered together and circumscribed by a wrapper (12). The rod includes a first sheet (2) of a first tobacco material and a second sheet (3) of a second tobacco material. The second sheet of the second tobacco material is physically or chemically different to the first sheet of the first tobacco material.
WO 2013178768 discloses a rod is formed from a first sheet comprising an aerosol-forming material (2) and a second sheet comprising a thermally-conductive material (3), the first and second sheets being gathered together and circumscribed by a wrapper (12). The rod may be used as a component part of an aerosol-generating article.
WO ‘766 and WO ‘768 talk about a sheet which is not cut into strands and directly fed to maker for rod formation.
To achieve the overall consumer acceptable sensory, that too in a HNB device, the rod formation at higher densities (say more than 300 mg/cc) is not possible using the tobacco flakes that goes in to conventional cigarettes. However, the inventors of the present invention provide heat not burn (HNB) aerosol generating smoking substrates which provide similar attributes as that of conventional cigarettes.

Object of the invention
An object of the present invention is to overcome the drawbacks of the prior art.
Another object of the present invention is to provide a heat not burn smoking substrate with same attributes of a conventional cigarette.
Yet another object of the present invention is to provide desired nicotine delivery in the shortest length possible with the less draw effort.
Still another object of the present invention is to provide a process of generating a heat not burn smoking substrate with same attributes of a conventional cigarette.

Summary of the invention
The following 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.
According to one aspect there is provided a process for preparation of an aerosol generating substrate for an aerosol generating article, wherein the process comprising the steps of:
(i) 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.

In another aspect there is an aerosol generating substrate produced by the process as described herein above.
In yet another aspect there is provided a substrate for an aerosol generating article, said substrate characterized by, having a lower cut per inch, preferably between 15 to 30, having a length ranging between 15-45 mm; higher pack 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 foregoing and additional features and advantages of the invention will be more readily apparent from the following detailed description, which precedes with reference to the accompanying drawings.

Brief Description of Accompanying Drawings
The features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are therefore not to be considered limiting of its scope the disclosure will be described with additional specificity and detail through use of the accompanying drawings.
Figure 1 shows the device with peripheral heating source.
Figure 2 shows the device with a core heating source.

Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not 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 to 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.

Description of the invention
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary.
Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the scope of the invention as defined by the appended claims and their equivalents.
It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.
Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.
It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, steps or components but does not preclude the presence or addition of one or more other features, steps, components or groups thereof.
As used herein, the term 'rod' is used to denote a generally cylindrical element of substantially circular, oval or elliptical cross-section.
As used herein, the term 'sheet' denotes a laminar element having a width and length substantially greater than the thickness thereof.
As used herein, the term 'strip' denotes a longitudinal element having a length substantially greater than the width and thickness thereof. The term ‘strand’ and ‘strips’ can be used interchangeably unless otherwise described.
As used herein, the term 'length' denotes the dimension in the direction of the cylindrical axis of strips according to the invention.
As used herein, the term 'width' denotes a dimension in a direction substantially perpendicular to the cylindrical axis of strips according to the invention.
As used herein, the term 'reconstituted tobacco material' denotes a pliant, homogeneous, paper-like sheet, which is produced in a process known from paper production of finely ground and rebundled raw tobacco or from clean fabrication waste also treated in this manner.
As used herein, the terms 'upstream' and 'downstream' are used to describe the relative positions of components, or portions of components, of smoking articles comprising rods according to the invention in relation to the direction of air drawn through the smoking articles during use thereof.
The present invention relates to a process for preparation of an aerosol generating substrate involving online creasing the reconstituted tobacco sheet to form cut strips and collating strips to form tobacco rod at extremely high densities.
The inventors of the present invention provide heat not burn (HNB) aerosol generating smoking substrates which provide similar attributes as that of conventional cigarettes.
Conventional tobacco: used in manufacturing of cigarettes (blended grades of leaf conditioned, cut and dried)
Cuts per inch (CPI): number of times leaf/tobacco sheet is cut in an inch (eg. 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)
The cuts per inch (CPI) for conventional tobacco and recon tobacco are different. Choosing the right substrate for heat-not-burn product always remains challenging. Because, the chosen substrate impacts the draw effort, fill value, density, nicotine delivery and so the end quality as well- sensorial. To achieve the overall consumer acceptable sensory, that too in a HNB device, the rod formation at higher densities (say more than 300 mg/cc) is not possible using the tobacco flakes that goes in to conventional cigarettes. If the density exceeds beyond 280 mg/cc, it becomes very difficult to pack, because of its springy nature and hence occupies more volume within the given space (measured in cc/10g i.e. more volume occupied with a given mass of material). Higher the packing and/or strands when, randomly oriented, leads to higher draw effort which is yet undesirable.
The present inventors have found that cutting the reconstituted (Recon) tobacco at lower cuts per inch and packing that cut Recon at extremely high densities without increasing the draw effort of the final rod when heated can deliver similar levels of nicotine as that of a conventional cigarette but with a shorter length. The present inventors have also found that cutting reconstituted tobacco substrate at lower cuts per inch than conventional tobacco, preferably between 15 to 30, so as to align more than 80% of the strands longitudinally while running online on maker at a circumference of around 20.0 - 25.0 mm and thereby achieve extremely high filling densities, ranging from about 450 mg/cc to 750 mg/cc, without an adverse impact on draw effort, below 1.5 mm Wg per mm of tobacco substrate.
The present process or preparation of the tobacco rods comprising aerosol generating substrate, the process comprising the steps of:
i) cutting reconstituted tobacco sheets into strips, specifically lower cuts per inch preferably between 15 to 30 and each strip having length of 15 mm to 45 mm,
wherein said substrate for an aerosol generating article further comprises 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 process involves by cutting the reconstituted tobacco sheets into strips, specifically having 15-30 cuts per inch and each strip having a length of 15 mm to 45 mm. Unlike conventional cut tobacco in cigarettes, this recon tobacco is heavier (filling value of recon tobacco made using band cast or dough process is around 18 cc/10g compared to 48 cc/10g of conventional tobacco). Cutting the sheet at lesser CPI than conventional tobacco makes it even heavier. As a result, these strips align themselves longitudinally in the maker.
An embodiment of the present invention provides an aerosol generating smoking substrate comprising reconstituted (Recon) tobacco at lower cuts per inch preferably between 15 to 30and each strip having a length of 15 mm to 45 mm.
Another embodiment is to provide an aerosol generating article formed at extremely high 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, using the above substrate.
Another embodiment is to use either a dough based process or band cast process for manufacturing Recon tobacco.
The present inventors found that the cutting the reconstituted tobacco sheet into lower cuts per inch strips, preferably 15 to 30 CPI during the preparation process ensures more than 80% longitudinal alignment of strands in the final rod, enabling packing at very high densities without impacting draw effort and thus making it useful for heat not burn products is unique to the invention. It also ensures that the resultant rods on heating can deliver similar levels of nicotine as that of a conventional cigarette but with a shorter length.
The tobacco rods prepared by the present process have a circumference of around 20.0 - 25.0 mm and thus achieve extremely high filling densities or packing density, ranging from about 450 mg/cc to 700 mg/cc.
In an embodiment of the present invention provides an aerosol generating devices comprising aerosol generating substrate prepared by the present process. Aerosol-generating device typically interacts with an aerosol-forming substrate to generate an aerosol. The aerosol-forming substrate forms a part of an aerosol-generating article, for example part of a smoking article. An aerosol-generating device may be a smoking device that interacts with an aerosol-forming substrate of an aerosol-generating article to generate an aerosol that is directly inhalable. It comprises an electric heating source (can be a core heater / peripheral or a combination thereof), which is typically located upstream to the aerosol-generating substrate.
Advantage of present invention:
1. packing at very high densities without impacting draw effort and thus making it useful for heat not burn products.
2. Is compatible with any kind of conventional aerosol generating device such as, but not limiting to, the device with peripheral heating source or the device with core heating source or combinations thereof (Refer figure 2 and 3).
,CLAIMS:1. A process for preparation of an aerosol generating substrate for an aerosol generating article, wherein the process comprising the steps of:
(ii) 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.
2. The process as claimed in claim 1, wherein the aerosol generating substrate is cut at lower cuts per inch than conventional tobacco, preferably between 15 to 30, and each strip having the length of preferably 15 mm to 45 mm, so as to align more than 80% of the strands longitudinally.
3. The process as claimed in any of the preceding claims wherein the aerosol generating substrate is cut at lower cuts per inch than conventional tobacco, preferably between 15 to 30, and each strip having the length of preferably 15 mm to 45 mm running online on maker at a circumference around 20.0 to 25.0 mm to achieve extremely high filling densities, ranging from about 450 mg/cc to 750 mg/cc.
4. An aerosol generating substrate produced by the process as claimed in claims 1 to 3.
5. A substrate for an aerosol generating article, said substrate characterized by,
having a lower cut per inch, preferably between 15 to 30,
having a length ranging between 15-45 mm;
higher pack 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.