SHEET OF A MATERIAL CONTAINING ALKALOIDS

Abstract

The present invention relates to a multi-layered sheet of a material containing alkaloids comprising:—a first layer comprising a substrate sheet including fibres having a mean fibre length comprised between about 1 millimetres and about 5 millimetres, the first layer defining a first surface and a second surface;—a second layer comprising a mixture of: # a powder of the material containing alkaloids, the powder having a size comprised between about 8 micrometers and about 200 micrometers; # water; # a binder; # an aerosol former; the second layer being applied to the first surface of the substrate sheet, and wherein the binder is comprised in an amount comprised between about 0 percent and about 1 percent of the total weight of the multi-layered sheet of material containing alkaloids.

Claims

1-14. (canceled)

15. A multi-layered sheet of a material containing alkaloids comprising: a first layer comprising a substrate sheet including fibres having a mean fibre length comprised between about 1 millimetres and about 5 millimetres, the first layer defining a first surface and a second surface; a second layer being applied to the first surface of the substrate sheet, the second layer comprising a mixture of: a powder of the material containing alkaloids, the powder having a size comprised between about 8 micrometers and about 200 micrometers; water; a binder in an amount comprised between about 0 percent and about 1 percent of the total weight of the multi-layered sheet of material containing alkaloids; and an aerosol former in an amount comprised between about 2.9 percent and about 8.5 percent of the total weight of the multi-layered sheet of material containing alkaloids or of the sheet of a composite material containing alkaloids.

16. The multi-layered sheet of a material containing alkaloids according to claim 15, wherein the first layer is partly impregnated with the second layer.

17. The multi-layered sheet of material containing alkaloids according to claim 15, comprising a third layer, the third layer comprising a mixture of: a powder of the material containing alkaloids, the powder having a size comprised between about 8 micrometers and about 200 micrometers; water; a binder; an aerosol former; the third layer being applied to the second surface of the substrate sheet.

18. A sheet of a composite material containing alkaloids comprising: a substrate sheet including fibres having a nominal average fibre length comprised between about 1 millimetres and about 5 millimetres and defining a first surface and a second surface; the substrate sheet being impregnated with a mixture of: a powder of the material containing alkaloids, the powder having a size comprised between about 8 micrometers and about 200 micrometers; water; a binder in an amount comprised between about 0 percent and about 1 percent of the total weight of the sheet of a composite material containing alkaloids; and an aerosol former in an amount comprised between about 2.9 percent and about 8.5 percent of the total weight of the multi-layered sheet of material containing alkaloids or of the sheet of a composite material containing alkaloids.

19. The multi-layered sheet of material containing alkaloids or the sheet of a composite material containing alkaloids according to claim 15, comprising the powder of the material containing alkaloids in an amount comprised between about 40 percent and about 80 percent of the total weight of the multi-layered sheet of material containing alkaloids or of the sheet of a composite material containing alkaloids.

20. The multi-layered sheet of material containing alkaloids or the sheet of a composite material containing alkaloids according to claim 15, comprising water in an amount comprised between about 7 percent and about 15 percent of the total weight of the multi-layered sheet of material containing alkaloids or of the sheet of a composite material containing alkaloids.

21. The multi-layered sheet of material containing alkaloids or the sheet of a composite material containing alkaloids according to claim 15, comprising fibres other than the fibres of the material containing alkaloids in an amount comprised between about 2 percent and about 5 percent of the total weight of the multi-layered sheet of material containing alkaloids or of the sheet of a composite material containing alkaloids.

22. The multi-layered sheet of material containing alkaloids or the sheet of a composite material containing alkaloids according to claim 15, wherein the multi-layered sheet of material containing alkaloids or the sheet of a composite material containing alkaloids has a thickness comprised between about 150 micrometers and about 400 micrometers.

23. The multi-layered sheet of material containing alkaloids or the sheet of a composite material containing alkaloids according to claim 15, wherein the multi-layered sheet of material containing alkaloids or the sheet of a composite material containing alkaloids has a width comprised between about 0.1 meters and about 2.0 meters.

24. The multi-layered sheet of material containing alkaloids or the sheet of a composite material containing alkaloids according to claim 15, wherein the powder of the material containing alkaloids comprises tobacco powder.

25. The multi-layered sheet of material containing alkaloids or the sheet of a composite material containing alkaloids according to claim 15, wherein the substrate sheet including fibres comprises cellulose fibres.

26. The multi-layered sheet of material containing alkaloids or the sheet of a composite material containing alkaloids according to claim 15, wherein the substrate sheet including fibres comprises fibres derived from hemp, kenaf, bamboo, wood, cotton, or silk.

27. Aerosol-generating article, comprising a portion of the multi-layered sheet of material containing alkaloids or of the sheet of the composite material containing alkaloids according to claim 15.

Description

[0107] Specific embodiments will be further described, by way of example only, with reference to the accompanying drawings in which:

[0108] FIG. 1 shows a flow diagram of a method to produce a sheet of homogenized tobacco material according to the invention;

[0109] FIG. 2 shows an enlarged view of one of the steps of the method of FIG. 1;

[0110] FIG. 3 shows a schematic perspective view of a first embodiment of an apparatus for production of a sheet of a material containing alkaloids according to the invention;

[0111] FIG. 4 shows a schematic lateral view in section of a second embodiment of an apparatus for production of a sheet of a material containing alkaloids according to the invention;

[0112] FIG. 5 shows a schematic lateral view in section of a third embodiment of an apparatus for production of a sheet of a material containing alkaloids according to the invention;

[0113] FIG. 6 shows a schematic lateral view in section of a fourth embodiment of an apparatus for production of a sheet of a material containing alkaloids according to the invention;

[0114] FIG. 7 shows a graph representing the composition of a cross section of a homogenized tobacco sheet produced with the method of the invention;

[0115] FIG. 8 shows a schematic representation of a lateral view of a multi-layered sheet according to the invention; and

[0116] FIG. 9 shows a schematic representation of a lateral view of a composite sheet according to the invention.

[0117] With initial reference to FIG. 1, the method for the production of a sheet of material containing alkaloids 200 is shown. In the shown embodiments, the sheet of material containing alkaloids 200 is a homogenized tobacco sheet and the material containing alkaloids is tobacco.

[0118] The first step of the method of the invention is the selection 100 of the tobacco types and tobacco grades to be used in the tobacco blend for producing the homogenized tobacco material. Tobacco types and tobacco grades used in the present method are for example bright tobacco, dark tobacco, aromatic tobacco and filler tobacco.

[0119] The selected tobacco types and tobacco grades intended to be production of the used for the homogenized tobacco material undergo the processing according to following steps of the method of the invention.

[0120] The method includes a further step 101 in which the selected tobacco is laid down. This step may comprise checking the tobacco integrity, such as grade and quantity, which can be for example verified by a bar code reader for product tracking and traceability. After harvesting and curing, the leaf of tobacco is given a grade, which describes for example the stalk position, quality, and colour.

[0121] Further, the lay down step 101 might also include, in case the tobacco is shipped to the manufacturing premises for the production of the homogenized tobacco material, de-boxing or case opening of the tobacco boxes. The de-boxed tobacco is then preferably fed to a weighing station in order to weight the same.

[0122] Moreover, the tobacco lay down step 101 may include bale slicing, if needed, as the tobacco leaves are normally compressed into bales in shipping boxes for shipping.

[0123] The following steps are performed for each tobacco type, as detailed below. These steps may be performed subsequently per grade such that only one production line is required. Alternatively, the different tobacco types may be processed in separate lines. This may be advantageous where the processing steps for some of the tobacco types are different. For example, in conventional primary tobacco processes bright tobaccos and dark tobaccos are processed at least partially in separate processes, as the dark tobacco often receives an additional casing. However, according to the present invention, preferably, no casing is added to the blended tobacco powder before formation of the homogenized tobacco web.

[0124] Further, the method may include a step 102 of grinding of the tobacco leaves. The grinding step 102 may be a single grinding step or a double grinding step, where the tobacco is firstly coarse grinded and then finely grinded.

[0125] Preferably, after the grinding step 102, a step of removal of non-tobacco material from the powder is performed (not depicted in FIG. 1). This removal step may be performed before grinding.

[0126] Removing the non-tobacco material may be easier before grinding because the non-tobacco material may be more easily recognisable and removed than after grinding.

[0127] Preferably, after the grinding step 102, the tobacco particles are transported, for example by pneumatic transfer, to a blending step 103.

[0128] In the blending step 103, all the grinded tobacco particles of the different tobacco types selected for the tobacco blend are blended. The blending step 103 therefore is a single step for all the selected tobacco types. This means that after the step of blending there is only need for a single process line for all of the different tobacco types. In FIG. 2, the blending of four coarse grinded tobacco particles of four different tobacco types selected for a tobacco blend, respectively schematically indicated by boxes 1, 2, 3 and 4, is represented.

[0129] In the blending step 103, preferably mixing of the various tobacco types in particles is performed.

[0130] Preferably a step of measuring and controlling one or more of the properties of the tobacco blend is performed.

[0131] Alternatively, the steps 102 is performed after the blending step 103, where the various tobacco types are blended together to form the desired blend. If performed after the blending step, the process may be faster.

[0132] It is to be understood that each tobacco type could be itself a sub-blend, in other words, the “bright tobacco type” could be for example a blend of Virginia tobacco and Brazil flue-cured tobacco of different grades.

[0133] The so obtained tobacco powder can be immediately used to form the tobacco slurry. Alternatively, a further step of storage of the tobacco powder, for example in suitable containers may be inserted (not shown).

[0134] From step 103 of fine blending, the tobacco powder is used in a subsequent slurry preparation step 104. The slurry preparation step 104 preferably comprises adding together an aerosol-former, a binder, and the grinded tobacco powder in a slurry mixing tank. More preferably, this step also includes processing the slurry with a high shear mixer to ensure uniformity and homogeneity of the slurry.

[0135] Preferably, the slurry preparation step 104 also includes a step of water addition, where water is added to the slurry to obtain the desired viscosity and moisture.

[0136] The slurry composition after step 104 is the following: [0137] Water: 30%-55% [0138] Tobacco powder: 40%-70% [0139] Binders: 0%-1% [0140] Aerosol-former: 1%-5% [0141] Added fibers: less than 0.5%

[0142] In order to form the homogenized tobacco sheet 200, preferably the slurry formed according to step 104 is cast in a casting or application step 105. Preferably, this casting step 105 includes transporting the slurry to a casting station and applying the slurry on a substrate sheet 11 (shown in FIGS. 3-6).

[0143] The homogenized cast sheet 200 is then dried in a drying step 106 comprising a uniform and gentle drying of the cast web. Preferably the drying step comprises monitoring the cast leaf temperature at each drying zone to ensure a gentle drying profile at each drying zone.

[0144] With now reference to FIG. 3, a first embodiment of an apparatus for the production of a sheet of homogenized tobacco 200 according to the present invention is represented and indicated with reference number 10.

[0145] Preferably, the apparatus 10 is adapted for the production of a plurality of sheets of homogenized tobacco material 200.

[0146] The apparatus 10 for the production of a sheet of homogenized tobacco material includes an extruder 5, a tank 6 positioned at an outlet 20 of the extruder 5 and a moving drum 7 located below the tank 6.

[0147] The extruder 5 comprises an inlet 21 where slurry 22 (indicated by an arrow in FIG. 3) to form the sheet of homogenized tobacco material is introduced, a screw 23 to extrude the slurry 22, and the outlet 20. The slurry 22 is pushed by the screw 23 from the inlet 21 to the outlet 20 (see again arrows 22 in FIG. 3). The screw 23 pushing the slurry 22 may be rotated by a motor 24, depicted schematically in FIG. 3 as a rectangle.

[0148] Slurry 22 reaches the extruder 5 from a different storing tank or silo, not shown in the appended drawings. Slurry 22 comprises tobacco powder, water, a binder and an aerosol former. Preferably the binder is guar. Preferably, the aerosol former is glycerine. Preferably, no further fibres are added in the slurry. Slurry is formed as described in step 104.

[0149] From the extruder 5, the slurry 22 reaches the tank 6. From the above composition, about 5 percent of water is removed from the slurry by the extrusion process.

[0150] The tank 6 comprises a plurality of outlets all indicated with 30. Tank 6 may have any geometrical shape, and in the depicted embodiment it is substantially a basin. Tank 6 includes lateral walls 32 and also further includes a bottom wall 33. A mixer 34 (indicated by an arrow in FIG. 3) can be present inside the tank 6 to stir and mix the slurry 22.

[0151] Further, a sensor 50 is present in the tank 6 to measure the vertical level of the slurry 22.

[0152] Preferably, a feedback is present between the sensor 50 and the extruder 5 so that the slurry is kept in the tank 6 at a substantially constant level.

[0153] Below outlet 30, the moving drum 7 is located. Moving drum 7 is adapted to rotate around its axis 77 in a direction of rotation 8 indicated by an arrow in FIG. 3. Moving drum 7 defines an external cylindrical surface 41.

[0154] Further, the apparatus 10 includes a plurality of bobbins 9 (a single bobbin is depicted in FIG. 3).

[0155] Each bobbin 9 of the plurality is made of coils of a substrate sheet 11, for example a cellulose fibres sheet. The bobbin is unwound and the free portion of the sheet 11 unwound from the bobbin 9 is positioned in contact with moving drum 7. The substrate sheet 11 includes a first and a second surface 12, 13, one opposite to the other. The second surface 13 is preferably in contact with cylindrical surface 41 of the moving drum 7. The first surface 12 faces at least one of the plurality of outlets 30. The rotation of the moving drum 7 causes a movement of the plurality of substrate sheets 11 along a common transport direction, indicated with arrow 14 in FIG. 3. The bobbins 9 are thus continuously unwound by the rotation of drum 7.

[0156] Each substrate sheet 11 of the plurality is in contact with the surface 41 of the moving drum 7 and, downstream the drum 7 along the transport direction, is free standing, that is, the first and second surfaces 12, 13 are not supported by any element. A further drum or roller (not visible in the drawing) may further pull the plurality of sheets 11 in the transport direction 14.

[0157] From the outlets 30, the slurry 22 is supplied to the plurality of substrate sheets 11. Preferably, each outlet 30 of the plurality of outlets supplies slurry 22 to a single substrate sheet 11 of the plurality of sheets. The slurry is delivered from the outlets 30 by gravity or applying pressure, for example by means of pump (not shown in the drawings). Preferably, the pump comprises a control (not visible in the drawing) of flow rate to control the amount of slurry delivered to the substrate sheet 11.

[0158] When the substrate sheet 11 is supplied with slurry 22, it becomes a homogenized tobacco sheet 200. The slurry may be absorbed by the substrate sheet 11 partly or completely. Most of the slurry may coat the substrate sheet 11, in particular the first surface 12.

[0159] Also the second surface 13 may be supplied with slurry 22.

[0160] Each outlet 30 preferably terminates with a nozzle 38 where the outlet 30 is present.

[0161] Further, preferably additional sensors (not shown) are arranged at the substrate sheet 200 downstream the outlets 30 to measure the weight per square centimetre and the thickness of the homogenized tobacco sheets 200. The sensor may be for example a nucleonic measuring head.

[0162] Additional sensors, not shown in the drawings, are preferably present as well, such as a sensor to locate and determine the positions of defects in the sheet of homogenized tobacco. A sensor to determine the moisture of the sheets 200 may be added. A sensor to measure a thickness of the sheet may be present. A sensor to check the alignment of the sheets in order to avoid misaligned and jammed sheets in case more than a single sheet is formed may be added.

[0163] The functioning of the apparatus 10 for forming the plurality of homogenized tobacco sheets 200 is as follows. Slurry 22, formed preferably mixing and combining tobacco powder, water and other ingredients, preferably with no or low content of added fibres, as described in step 104, is transferred from a storing tank (not shown) using for example in line mixers (also not shown) to the extruder 5. The slurry reduces its water contents at the extruder 5 and it is extruded inside the tank 6. In tank 6, the slurry reaches outlets 30, with or without the needs of pump. Nozzle 38 supplies slurry onto substrate sheet 11 including fibres which is positioned in contact to moving drum 7.

[0164] Movements of drum 7 causes the shift of substrate sheets 11 along transport direction 14. Each nozzle 38 deposits slurry on a different substrate sheet 11. A plurality of homogenized tobacco sheets 200 is thus formed.

[0165] The thickness of the sheets 200 and grammage controlled by nucleonic gauge immediately after slurry supply are preferably continuously monitored and feedback-controlled using slurry measuring device.

[0166] In FIG. 4, a second embodiment of an apparatus 110 for the production of the homogenized tobacco sheet 200 is shown. The apparatus 110 comprises a casting box 42 containing slurry 22 and a substrate sheet 11, wherein a casting roller 45—associated to the casting box 42—casts the slurry 22 contained in the casting box 42 onto the substrate sheet 11 so as to form the cast sheet 200 of homogenized tobacco material. Slurry 22 is prepared as in step 104 above described.

[0167] Substrate sheet 11 is wound around moving rollers (only roller 52 is shown) and is positioned above casting box 42. The substrate sheet 11 defines a first surface 12 and a second surface 13 and is moved by the moving rollers 52 in a transport direction 14 indicated with an arrow in FIG. 4.

[0168] The casting box 42 comprises side walls including a first wall 43 and a second opposite wall 44.

[0169] The casting box 42 is generally defined by four side walls, that is, the first wall 43 and second opposite wall 44 and a third wall and a fourth opposite wall (not shown in the figures), which connect the first wall 43 and second opposite wall 44.

[0170] Further, casting box 42 includes a bottom wall 46. It also includes an aperture 47, in this case coinciding with a top of the casting box. The aperture 47 is positioned in proximity of the substrate sheet 11.

[0171] The incoming slurry 22 is introduced into the casting box 42 from an inlet (not visible), in particular the end of a pipe, for example connected to one of the side walls of the casting box.

[0172] The slurry 22 from buffer tanks (not shown in the drawings) is transferred into the casting box 42 usually by means of a pump (not shown in the drawings). Preferably, the pump comprises a control (not visible in the drawing) of flow rate to control the amount of slurry 22 introduced in the casting box 42. The pump is advantageously designed to ensure that slurry transfer times are kept to the minimum necessary.

[0173] The amount of slurry 22 in the casting box 42 has a pre-determined level, which is preferably kept substantially constant or within a given range. In order to keep the amount of slurry 22 substantially at the same level, the pump controls the flow of slurry 22 to the casting box 42.

[0174] The casting roller 45 is associated to the casting box 42 in order to cast the slurry. The casting roller 45 has a dominant dimension which is its longitudinal width. The casting roller defines a first rotation axis 48 (indicated with a cross in FIG. 4) which corresponds to its longitudinal direction.

[0175] Preferably first rotation axis 48 is horizontal and more preferably perpendicular to the casting direction 17.

[0176] The casting roller 45 is attached in a rotatable manner to the casting box 42, preferably by means of its ends, to two opposite side walls. Further, the casting roller 45 protrudes partially from aperture 47 and faces substrate sheet 11 (see in detail FIG. 4).

[0177] Between the casting roller 45 and the substrate sheet 11 a gap may be present, the dimensions of which determine—among others—the thickness of the cast web 200 of homogenized tobacco material.

[0178] The slurry 22 is cast on the substrate sheet 11 through the casting roller 45, which creates a continuous sheet 200 of homogenized tobacco material. The slurry is cast on the first surface 12 of the substrate sheet 11 facing the roller 45.

[0179] The thickness of the sheet may be further controlled by lamination rollers 52, 53. Moving roller 52 may be part of a couple of lamination rollers 52, 53 having a gap therebetween where the sheet 200 is inserted. Lamination Rollers 52, 53 are used in order to facilitate the absorption and wetting of the cellulose fibers of the substrate sheet 11 and to achieve a control of the final thickness of the sheet 11.

[0180] The cast sheet 200 is driven by the moving rollers 52 along the transport direction 14 and enters a heating unit (not shown in the figures), where it is progressively heated and homogeneously dried.

[0181] The functioning of the apparatus 110 for forming the homogenized tobacco sheets 200 is as follows. Slurry 22, formed preferably mixing and combining tobacco powder, water and other ingredients, preferably with no or low content of added fibres, as described in step 104, is transferred from a storing tank (not shown) using for example in line mixers (also not shown) to the casting box 42. Casting roller 45 supplies slurry onto fibres containing substrate sheet 11 by rotating while the substrate sheet 11 moves along transport direction 14. A layer of slurry is thus deposited on the first surface 12 of the substrate sheet 11 forming a homogenized tobacco sheet 200.

[0182] The thickness of the sheets 200 and grammage controlled by nucleonic gauge immediately after slurry supply are preferably continuously monitored and feedback-controlled using a slurry measuring device.

[0183] In FIG. 5, a third embodiment of an apparatus 120 for the production of the homogenized tobacco sheet 200 is shown. The apparatus 120 is similar to apparatus 110 of FIG. 4, so only differences between the two apparatuses will be outlined.

[0184] In addition to the casting roller 45, apparatus 120 comprises, in the casting box 42, also a second roller, transfer roller 49. The transfer roller 49 is located below the casting roller 45. The transfer roller 49 preferably has a diameter bigger than a diameter of the casting roller 45. Preferably, transfer roller 49 is cylindrical and defines a second rotation axis 51 (indicated with a cross in FIG. 5) parallel to first rotation axis 48. The transfer roller 49 is attached in a rotatable manner to two opposite side walls of the casting box 42, preferably by means of its longitudinal ends. Further, the transfer roller 49 is preferably located within casting box 42 in its entirety and it is submerged by slurry 22 at least in part. The rotation direction of the transfer roller 49 is opposite to the rotation direction of casting roller 45.

[0185] Between the casting roller 49 and the casting roller 45, a gap is formed.

[0186] The transfer roller 49 thus is in contact with the slurry and transfers it to casting roller 45 which applies the slurry to the substrate sheet 11 as detailed with reference to apparatus 110.

[0187] In the functioning of the apparatus 120, the slurry 22 is supplied to the casting box 42 at the inlet.

[0188] The slurry reaches a given level. The transfer roller 49 is partially in contact with the slurry 22 in the casting box when it reaches the given level and, due to its rotation, it covers its outer surface with a layer of slurry 22, so that there is a slurry coating on transfer roller 49. This slurry coating in transfer roller 49 is transferred to the casting roller 45. The slurry is then transferred to casting roller 45 due to the contact between slurry layer on transfer roller 49 and the surface of casting roller 45, and a slurry coating layer is formed on the surface of casting roller 45 before its final transfer to substrate sheet 11.

[0189] Casting roller 45 rotates around axis 48 and the slurry layer touches substrate sheet 11. This causes a transfer of the slurry from casting roller 45 to substrate sheet, where the slurry coating forms the cast web 200.

[0190] The web is then preferably dried and wound up into bobbins for storage (not shown in the figures).

[0191] These bobbins are later unwound and used to create the tobacco component for aerosol generating articles.

[0192] In FIG. 6, a fourth embodiment of an apparatus 130 for the production of the homogenized tobacco sheet 200 is shown. The apparatus 130 is similar to apparatus 120 of FIG. 5, so only differences between the two will be outlined.

[0193] The apparatus 130 includes, in addition to the configuration depicted with reference to apparatus 120, a counter pressing roller 56 located above the casting roller 45. Between the casting roller 45 and the counter pressing roller, a gap is formed. In the gap, the substrate sheet 11 is positioned.

[0194] The slurry 22 cast by the casting roller 45 reaches the substrate sheet and it is pressed between the casting roller 45 and counter pressing roller 56. Casting roller 45 and counter pressing roller 56 press the first and the second surfaces 12, 13 of the substrate sheet 11, respectively.

[0195] The quantity of slurry coming out of the casting box 42 could then be controlled by adjusting the distance between the two rollers 45 and 49 (casting roller and transfer roller). The quantity of slurry applied on the substrate sheet 11 could furthermore be adjusted by controlling the pressure exerted on the sheet by the casting roller 46 and the counter pressing roller 56.

[0196] Acting on the pressure exerted on the sheet helps to have a good control on the slurry deposition on the substrate sheet 11.

[0197] The functioning of apparatus 130 is the same as apparatus 120, to which the compression by the counter pressing roller 56 is added.

[0198] As depicted in FIG. 7, a graph regarding the concentration of various components of the sheet of homogenized tobacco 200 is depicted. The continuous curve represents the concentration of the slurry in the sheet, while the dashed curve represents the concentration of the material forming the substrate. The abscissa of the graph represents the position in the substrate sheet 11, from the first surface 12 of the substrate sheet to the second surface 13 of the substrate sheet. In case the slurry 22 is put on one surface, as the first surface 12, of the substrate sheet 11, the slurry will have a decreasing concentration (in percent of the mass of the tobacco sheet reported to the total mass of a unit volume) going from the first surface 12 to the second surface 13 through the substrate sheet thickness.

[0199] Such decreasing concentration could vary according to the recipe of slurry, the distribution size of the tobacco particles and the nature of the fibers substrate 11.

[0200] For instance, in the area of the first surface 12 where the slurry is applied, the slurry content could go from about 70-80 percent (in percent of the mass of the tobacco compound reported to the total mass of a unit volume) down to about 25-20 percent on the second surface 13. The fibers substrate may go from about 30-20 percent on the first surface 12, to about 75-80 percent in the area of the second surface 13.

[0201] The shapes of the curves in FIG. 7 is only schematic.

[0202] This configuration of the homogenized tobacco sheet 200 can be obtained using any of the apparatuses 10, 110, 120 and 130 of FIGS. 3-6.

[0203] The sheet of homogenized tobacco 200 may be a multi-layered sheet or a sheet of a composite material, depending on the absorption of slurry into the substrate sheet. FIG. 8 shows a multi-layered sheet 200 where the slurry 22 coats the substrate sheet 13, forming a second layer 201. In FIG. 9, the slurry 22 is substantially all absorbed by the substrate sheet 13, and a composite sheet 200 is formed.