Tobacco product and method of making same

Abstract

A method of manufacturing a fire-proof reconstituted tobacco component is disclosed, the method comprising the steps of: grinding a tobacco material to produce ground tobacco fibers; treating the ground tobacco fibers by applying a treatment agent comprising a donor of phosphorus groups, wherein the donor of phosphorus groups comprises a phosphoinositide moiety; heating the treated tobacco fibers to obtain phosphorus treated tobacco fibers; and processing the phosphorus-treated tobacco fibers to produce a fire-resistant reconstituted tobacco component.

Description

Technical Field

[0001] The present invention relates to tobacco products and, in particular, to the manufacture of fire-resistant reconstituted tobacco components for heat-not-burn applications. Background Art

[0002] Aerosol-generating articles typically heat a consumable product to produce an aerosol or vapor that is inhaled by the user. Historically, tobacco products, such as conventional cigarettes, were ignited or burned to produce tobacco smoke. More recently, heat-not-burn (HnB) products have been developed that do not require the combustion of tobacco consumables.

[0003] Known regulations require that all HnB tobacco products be non-combustible. For example, heated tobacco sticks cannot be ignited like conventional cigarettes. Consequently, known HnB products use metallized wrappers or cigarette paper treated with additives to render them non-combustible and flame-retardant. Such technologies are often non-biodegradable and potentially toxic to humans or animals.

[0004] An object of the present invention is to provide an effective fire-resistant reconstituted tobacco component for heat-not-burn applications. Summary of the Invention

[0005] According to aspects of the present invention, there is provided a method for making a fire-resistant reconstituted tobacco component, the method comprising: grinding tobacco material to produce ground tobacco fibers; treating the ground tobacco fibers by applying a treating agent comprising a donor of a phosphorus group, wherein the donor of the phosphorus group comprises a phosphoinositide moiety; heating the treated tobacco fibers to obtain phosphorus-treated tobacco fibers; and processing the phosphorus-treated tobacco fibers to produce a fire-resistant reconstituted tobacco component.

[0006] In this way, the consumables that produce non-combustible heat-not-burn (HnB) aerosol have fireproof characteristics and are nontoxic and biodegradable. Advantageously found that, before making reconstituted tobacco component, grinding tobacco material and processing ground tobacco fiber (contrary to processing reconstituted tobacco component after making reconstituted tobacco component) significantly improved the covalent bonding of the donor of phosphorus group and tobacco fiber.When phosphorus compound was in treatment solution, the donor of phosphorus group was not yet bonded or grafted on the tobacco fiber.After processing (namely after the chemical reaction that the donor of phosphorus group was bonded on the tobacco fiber therein), phosphorus group bonding / grafting is on the tobacco fiber (thereby treated tobacco fiber is provided). Fireproof reconstituted tobacco component (also referred to as reconstituted tobacco blend (RTB)) can comprise the phosphorus group by weight 0.1% to 10%, preferably between 0.5% to 3% of the gross weight of reconstituted tobacco component.

[0007] Advantageously, the fireproof reconstituted tobacco of the present invention that is claimed is carbonized when heated and does not ignite.The phosphorus group that has been grafted on the tobacco promotes the carbonization of tobacco fiber at high temperature, and this forms the protective char layer that serves as a flame retardant.The level or degree of this carbonization can be from 15% to 40%, preferably change between 15% to 20%.

[0008] Preferably, the ground tobacco fibers comprise microfibers having an average diameter of less than 400 μm (micrometers) and / or nanofibers having an average diameter of less than 500 nm (nanometers). In this way, the optimal average diameter of the ground tobacco fibers ensures that the appropriate amount of phosphorus groups are bonded to the tobacco fibers to ensure effective fire-resistant reconstituted tobacco components. It has also been found that grinding the tobacco material to have an average diameter throughout the fiber also ensures a more uniform distribution of tobacco fibers, which improves the ease of forming fire-resistant reconstituted tobacco components. Grinding can be carried out by a mechanical dispersion grinder and a homogenizer.

[0009] The donor of the phosphorus group comprises a phosphoinositol moiety. For example, phytic acid is a donor of the phosphorus group, which has a phosphoinositol moiety. Other examples include: D-inositol 1,4,5-triphosphate tripotassium salt and D-inositol 1,3,4,5-tetrakis(phosphate)ammonium salt. As will be appreciated by those skilled in the art, other phosphorus-based compounds may also be used as donors of the phosphorus group.

[0010] Advantageously found that the inositol phospho-derivative / part allows multiple phosphorus groups from the same inositol phospho-derivative to be grafted on multiple tobacco fibers. In other words, a kind of inositol phospho-derivative allows to form multiple covalent bonds between phosphoinositol derivative and tobacco fiber. In this way, the amount of the required treatment solution that guarantees effective fireproofing characteristics can be reduced, thereby improving the ease and the cost of making fireproof reconstituted tobacco component / RTB.

[0011] Preferably, the treatment solution comprises 0.1% to 20% by weight, preferably 3% to 10% phosphoinositide derivatives, such as phytic acid (PA) of the gross weight of the treatment solution. Preferably, the phosphoinositide derivatives comprise phytic acid. In this way, the phosphorus group of the phosphoinositide derivatives can catalyze the carbonization of tobacco material fibers, to form a dense and protective char layer on the tobacco fiber surface. This protective layer hinders the heat transfer between adjacent and surrounding tobacco fibers, which in turn provides the fireproofing properties of the reconstituted tobacco component. Most preferably, the treatment solution comprises 0.1% to 20% by weight, preferably 3% to 10% phytic acid (PA) of the gross weight of the treatment solution.

[0012] Preferably, the treatment solution comprises 1% to 40%, preferably 10% to 20% urea by weight of the gross weight of the treatment solution. In this way, in the treatment application step, urea serves as an enabler that improves the accessibility of the phosphorus group in the phosphoinositide derivative (such as phytic acid) to the individual tobacco fibers and ensures effective covalent bonding. Urea also protects the tobacco fiber material from degradation (such as drying the pulp before heating or making paper) when heated at a later stage after solution treatment.

[0013] The ground tobacco fibers can be applied with the treating solution by soaking the tobacco fibers in the treating solution or by spraying the treating solution onto the ground tobacco fibers.

[0014] Preferably, the ratio of ground tobacco fibers to treatment solution is between 1: 1 and 1: 10, most preferably 1: 5. In this way, wetting of the tobacco fibers can be carried out efficiently and ensures that the tobacco fibers are effectively treated.

[0015] Preferably, the treatment of the ground tobacco fibers comprises a soaking process or a spraying process. Preferably, when the ground tobacco fibers are treated by soaking, the treatment of the ground tobacco fibers further comprises a drying step performed after the soaking process, the drying step being carried out under atmospheric conditions for between 5 minutes and 8 hours, preferably between 15 min and 30 min, and at a temperature in the range of 15°C to 60°C (degrees Celsius), preferably in the range of 40°C to 60°C. The moisture content of the treated tobacco fibers after the drying step is in the range of 5% to 20% by weight of the total weight of the treated ground tobacco fibers.

[0016] Preferably, the treated tobacco fibers are heated at 140° C. to 200° C. Heating the tobacco fiber treatment solution mixture ensures that the phosphorus group donors in the solution can be effectively covalently bonded to the tobacco fibers.

[0017] Preferably, before applying the treatment solution, the method further comprises using steam explosion to obtain nanofibers with an average diameter of less than 500 nm on the ground tobacco fibers. Preferably, the plant tobacco fibers are tobacco stems. In this way, tobacco nanofibers with an average diameter of less than 500 nm (nanometer) are obtained. Advantageously, these tobacco nanofibers can be used to improve the mechanical properties of the final fireproof reconstituted tobacco material, such as the tolerance and filling capacity of the final fireproof reconstituted tobacco sheet. These tobacco nanofibers also provide enhanced tobacco flavor. The tobacco material is pretreated so that smaller fibers or nanofibers can be obtained more easily. The tobacco fibers obtained by steam or steam explosion can have a diameter between 50 and 500 nm, preferably between 50 and 100 nm.

[0018] Preferably, the method further comprises a step of refining the ground tobacco fibers. In this way, the ground tobacco fibers can be "ground" to produce fibrils. The refining step can be performed by passing the tobacco fibers through a disc refiner, so that fibrils are formed when the tobacco fibers pass between the blades of the disc refiner.

[0019] It has been found that fibrils enhance the bonding / grafting process (i.e., treatment with a donor solution of phosphorus groups). The fibrils also provide improved "entanglement" of the tobacco fibers with one another (e.g., through electrostatic forces), which in turn improves the uniformity of tobacco fiber distribution when forming the fire-resistant reconstituted tobacco component.

[0020] Preferably, prior to the grinding step, the method further comprises the steps of mixing the tobacco leaves with water to form a tobacco mixture; and dehydrating the tobacco mixture to obtain a tobacco concentrate and tobacco material for grinding, wherein the tobacco concentrate is recombined with the phosphorus-treated tobacco fibers in the processing step.

[0021] According to another aspect of the present invention, there is provided a fire resistant reconstituted tobacco component comprising 0.1% to 10%, preferably 0.5% to 3% by weight of phosphorus groups, based on the total weight of the reconstituted tobacco component, and wherein the phosphorus groups comprise phosphoinositide moieties.

[0022] Preferably, the phosphorus groups are covalently grafted onto the ground tobacco plant fibers of the reconstituted tobacco component. Examples include phytic acid (inositol hexaphosphate) or phytate as a salt, D-inositol 1,4,5-triphosphate tripotassium salt and / or D-inositol 1,3,4,5-tetrakis(phosphate)ammonium salt.

[0023] Preferably, the fire-resistant reconstituted tobacco component comprises ground tobacco fibers comprising microfibers having an average diameter of less than 400 micrometers and / or nanofibers having an average diameter of less than 500 nm.

[0024] According to another aspect of the present invention, an aerosol-generating article for use with a heat-not-burn aerosol-generating device is provided. The aerosol-generating article comprises an aerosol-generating substrate. The aerosol-generating substrate comprises a tobacco component wrapped in cigarette paper to form a tobacco rod. The tobacco component comprises fire-resistant reconstituted tobacco as defined above. In particular, the fire-resistant reconstituted tobacco comprises 0.1% to 10%, preferably 0.5% to 3%, by weight of phosphorus groups, based on the total weight of the fire-resistant reconstituted tobacco, and wherein the phosphorus groups comprise phosphoinositide moieties.

[0025] The aerosol-generating article may further include a downstream section extending from the downstream end of the aerosol-generating substrate to the downstream end of the aerosol-generating article. The downstream section may also be referred to as the mouth end. The downstream section may include one or more downstream elements or sections, including: a filter plug, a central aperture, a support tube (which may include paper), an aerosol cooling section, and / or a mouthpiece. The downstream elements may be arranged downstream of, and preferably adjacent to, the aerosol-generating substrate of the aerosol-generating article such that, in use, aerosol generated from the aerosol-generating substrate upon application of heat flows through the downstream section for inhalation by a user.

[0026] Preferably, the aerosol generating article comprises an aerosol generating substrate comprising fire resistant reconstituted tobacco as defined above. In particular, the fire resistant reconstituted tobacco contains 0.1% to 10%, preferably 0.5% to 3% by weight of phosphorus groups, based on the total weight of the fire resistant reconstituted tobacco. The aerosol generating article also comprises a downstream section comprising an aerosol cooling section adjacent to the downstream end of the aerosol generating substrate and a suction nozzle adjacent to the downstream end of the aerosol cooling section. Most preferably, the aerosol cooling section can be a paper tube or a section comprising a curled polylactic acid sheet. Most preferably, the suction nozzle comprises a filter plug.

[0027] Preferably, the aerosol generating article comprises an aerosol generating substrate comprising fire resistant reconstituted tobacco as defined above. In particular, the fire resistant reconstituted tobacco contains 0.1% to 10%, preferably 0.5% to 3% by weight of phosphorus groups, based on the total weight of the fire resistant reconstituted tobacco. The aerosol generating article also comprises a downstream section comprising an aerosol cooling section adjacent to the downstream end of the aerosol generating substrate, a center hole adjacent to the downstream end of the aerosol cooling section, and a suction nozzle adjacent to the downstream end of the center hole. Most preferably, the aerosol cooling section can be a paper tube or a section comprising a curled polylactic acid sheet. Most preferably, the suction nozzle comprises a filter plug.

[0028] Preferably, the aerosol generating article comprises an aerosol generating substrate comprising fire resistant reconstituted tobacco as defined above. In particular, the fire resistant reconstituted tobacco contains 0.1% to 10%, preferably 0.5% to 3% by weight of phosphorus groups, based on the total weight of the fire resistant reconstituted tobacco. The aerosol generating article also comprises a downstream section comprising a first central hole having a first inner diameter adjacent to the downstream end of the tobacco component, a second central hole having a second inner diameter adjacent to the downstream end of the first central hole, and a mouthpiece adjacent to the downstream end of the second central hole. Most preferably, the first inner diameter is smaller than the second inner diameter. The first inner diameter may range from 1.5 mm (millimeters) to 4.5 mm. The second diameter may range from 3.5 mm to 6.0 mm. Most preferably, the mouthpiece comprises a filter plug.

[0029] Preferably, the aerosol generating article comprises an aerosol generating substrate comprising fire resistant reconstituted tobacco as defined above. In particular, the fire resistant reconstituted tobacco contains 0.1% to 10%, preferably 0.5% to 3% by weight of phosphorus groups, based on the total weight of the fire resistant reconstituted tobacco. The aerosol generating article also comprises a downstream section comprising a central hole having an inner diameter adjacent to the downstream end of the tobacco component, an aerosol cooling section adjacent to the downstream end of the central hole, and a mouthpiece adjacent to the downstream end of the aerosol cooling section. The inner diameter of the central hole may range from 1.5 mm (millimeters) to 4.5 mm. The aerosol cooling section may be a paper tube or a section comprising a curled polylactic acid sheet. Most preferably, the mouthpiece comprises a filter plug.

[0030] In another embodiment, an aerosol-generating article according to any of the aforementioned aerosol-generating articles may further include an upstream element. Such an upstream element may be arranged upstream of, and preferably adjacent to, the tobacco component (i.e., the aerosol-generating substrate) of the aerosol-generating article. The upstream element may be a filter plug made of cellulose acetate with or without a central hole, a paper filter with or without a central hole, or a combination thereof. Preferably, the upstream element is wrapped in fire-resistant cigarette paper together with the tobacco component. In some other examples, the fire-resistant cigarette paper may only wrap the upstream element. In this case, the tobacco component is wrapped in conventional cigarette paper that does not have fire-resistant properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0032] Figure 1A shows a flow chart illustrating a first grafting process according to an embodiment of the present invention;

[0033] Figure 1B shows a flow chart illustrating a second grafting process according to the present invention;

[0034] Figure 2 A flow chart illustrating a method for forming a reconstituted tobacco component according to the present invention is shown; and

[0035] Figure 3 A flow chart illustrating another method for forming a reconstituted tobacco component according to an embodiment of the present invention is shown.

[0036] Figure 4 A flow chart illustrating a third grafting process according to the present invention is shown.

[0037] Figure 5 A schematic diagram of a heated tobacco rod having a fire-resistant reconstituted tobacco component according to the present invention is shown. DETAILED DESCRIPTION

[0038] As used herein, the terms "burn retardant" or "fire retardant" or "fire repellent" or "fireproof" or "fireproofing" are used equivalently and refer to a component that reduces or even prevents the flammability of a material by physically impeding the initiation of a fire or by initiating a chemical reaction that stops or prevents the development of a fire. In the sense of the present invention, "burn retardant" or "fire retardant" or "fire repellent" or "fireproof" or "fireproofing" reduces or even prevents the combustion of tobacco material.

[0039] As used herein, the term "donor of a phosphorus group" refers to a chemical component comprising at least one phosphorus atom available for covalent bonding to a host material, also referred to as an acceptor.

[0040] As used herein, the term "inositol" or "myo-inositol" refers to a carbon ring sugar and is the biologically important form of cyclohexane-1,2,3,4,5,6-hexanol. In the context of the present invention, we specifically refer to "phosphoinositol derivatives / moieties" to define inositol components in which at least one hydroxyl moiety in the inositol component is substituted with a phosphite moiety. In preferred embodiments, more than one hydroxyl moiety of the inositol component is substituted with a phosphite moiety. In a most preferred embodiment, all six hydroxyl moieties of the inositol component are substituted with phosphite moieties.

[0041] As used herein, the term "covalent bond" refers to a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are called shared pairs or bonding pairs. When atoms share electrons, the stable balance of attractive and repulsive forces between the atoms is called covalent bonding. For many molecules, the shared electrons allow for a stable electronic configuration.

[0042] Figure 1A and 1B A schematic diagram of the grafting process of fire-resistant tobacco fibers according to the present disclosure is shown. The tobacco fibers of the present disclosure are ground prior to the grafting process.

[0043] Figure 1A A first grafting method 100 is shown, wherein ground tobacco fibers are immersed in an aqueous treatment solution comprising a donor of phosphorus groups and urea at step 105. The composition of the aqueous treatment solution includes:

[0044] - 0.1 to 20% by weight, preferably between 3 and 10% by weight, of a donor of phosphorus groups, based on the total weight of the treatment solution, and

[0045] - 1 to 40% by weight, preferably between 10 and 20% by weight, of urea based on the total weight of the treatment solution.

[0046] In particular, the donor of the phosphorus group may be phytic acid (inositol hexaphosphate) or phytate as a salt, D-inositol 1,4,5-triphosphate tripotassium salt and / or D-inositol 1,3,4,5-tetrakis(phosphate)ammonium salt.

[0047] The ratio of ground tobacco fiber and aqueous treatment solution is at 1 part of material: 1 part of solution to 1 part of material: 10 parts of solution and between.For example, 1 gram of ground tobacco fiber is than the solution of 1 ml, or 1 gram of ground tobacco fiber is than the treatment solution of 10ml.Preferably, ratio is the aqueous treatment solution of 1 gram of ground tobacco fiber than 5 ml.To be immersed in the treatment solution through ground tobacco fiber and continue the time period between 5 to 60 minutes.

[0048] Step 110 is an optional step, wherein filters through ground tobacco fiber-treatment solution mixture to remove any excessive treatment solution and / or any undesirable particle from mixture.Then in step 115, will be through soaked mixture drying so that the mixture is dried to the desired humidity level / moisture content.Drying is carried out the time period between 5 minutes and 8 hours at a temperature between 40 ℃ to 60 ℃ under atmospheric conditions.Desired humidity level or moisture content are between 5% and 20% in percentage by weight of the gross weight of mixture.

[0049] The partially dried mixture is then heated at a temperature of 140°C to 200°C for a duration of 2 hours in step 120 to graft the donors of phosphorus groups in the aqueous treatment solution onto the ground tobacco fibers.

[0050] The above references can be added, removed or modified Figure 1A The multiple steps in the method described above can be combined to provide another fire-resistant process according to the present disclosure. For example, in its simplest form, phosphorus groups can be grafted onto tobacco fibers simply by applying the treatment solution through soaking (i.e., only step 105 without any further filtering, drying or heating steps). Alternatively, the grafting process can include only the soaking step 105 and the heating step 120.

[0051] After processing the ground tobacco fibers, the treated tobacco fibers can be washed and filtered before being made into fire-resistant reconstituted tobacco products. The treated tobacco fibers are washed and filtered to remove any excess solvent and molecules. Chemically pure urea is a colorless and odorless solid that does not interfere with the color or mechanical properties of the final product.

[0052] Figure 1B A second grafting process 150 is shown, wherein the ground tobacco fibers are sprayed (instead of soaked) with an aqueous treatment solution of the above-mentioned donor of phosphorus groups and urea in step 155. In particular, the donor of phosphorus groups can be phytic acid (inositol hexaphosphate) or a phytate as a salt, D-inositol 1,4,5-triphosphate tripotassium salt and / or D-inositol 1,3,4,5-tetrakis(phosphate)ammonium salt.

[0053] In step 155, the ground tobacco fibers are sprayed with an aqueous treatment solution of a donor of phosphorus groups and urea to a moisture level / moisture content of 5% to 20%. Spraying the ground tobacco fibers allows for better control of the moisture content of the mixture, which means that the drying step 115 of the first method 100 is not necessary in the present method 150.

[0054] After spraying, the tobacco fibers are heated at a temperature of 140° C. to 200° C. for a duration of 2 hours in step 160 in the same manner as the heating step 120 in the first method 100 .

[0055] The heating step 160 is optional and can be removed or modified to provide another fire-resistant process in which the phosphorus groups can be grafted onto the tobacco fibers simply by applying the treatment solution by spraying the treatment solution onto the ground tobacco fibers. In addition, after treating the ground tobacco fibers, the treated tobacco fibers can be optionally washed and filtered before being made into a fire-resistant reconstituted tobacco product.

[0056] Figure 2 A schematic diagram of a method 200 of making a fire-resistant reconstituted tobacco component is shown.

[0057] Tobacco leaves are first prepared by mixing with water to extract the tobacco essence from the leaves into the water in step 205. The mixture is then dehydrated in step 210, and in step 215 the tobacco essence water is extracted from the mixture and concentrated into a tobacco concentrate for later use.

[0058] Then in step 220, the dehydrated tobacco leaf is ground into the micron and / or nanofiber of tobacco material by using a mechanical dispersion grinder and a homogenizer. The tobacco material can be ground in water to improve the dispersion of the material and to ensure the best uniformity of the ground tobacco fiber. The tobacco material is ground into microfibers with an average diameter between 60 and 400 μm (micrometers), preferably between 60 and 200 μm, and / or nanofibers with an average diameter between 50 and 500 nm (nanometers), preferably between 50 and 100 nm. Alternatively, steam explosion can also be used to pre-treat tobacco material (particularly tobacco stems) to obtain nanofibers. Nanofibers improve the mechanical properties (tolerance and filling capacity) of reconstituted tobacco sheets and also enhance tobacco taste.

[0059] The tobacco material may be bleached before or after the grinding step 220 to remove lignin from the tobacco material.

[0060] In step 225, the ground tobacco fibers are passed through a disc refiner. A disc refiner can be used to affect the structural and bonding characteristics of plant tobacco fibers. In this case, the ground tobacco fibers are abraded or ground to form fibrils on their surface, which improves the bonding characteristics of the tobacco paper mixture and allows for more efficient refractory treatment in the next step.

[0061] After the tobacco is ground into fibers, then in step 230 according to the above reference Figure 1A The first grafting process 100 or the second grafting process 150 described in 1B is to perform a fire-resistant treatment on the ground tobacco fibers.

[0062] Following the grafting process, an additional optional washing step may be performed after heating in step 235 to further remove any excess treatment solution containing donors of phosphorus groups that have not reacted with the ground tobacco fibers.

[0063] The treated tobacco fiber is then made into tobacco paper. In step 240, the treated tobacco fiber-treatment solution mixture is filtered and then processed by a paper machine. In step 245, the mixture is continuously sprayed onto a forming wire or forming fabric from a headbox. The forming fabric is a fine mesh fabric, and water or excessive treatment solution will be gradually sucked out / removed from top mixture by this fine mesh fabric. At the end of the forming fabric, the mixture is the form of a tobacco sheet, typically containing less than 80% water / moisture.

[0064] The treated tobacco sheet is then transferred via a support belt to a pressing or press section in step 250, where the pressing section is configured to further remove moisture from the sheet. The pressed sheet is then transferred to a rolling section in step 255, where it is passed through a series of heated cylinders. At this stage, or just before step 255, the tobacco concentrate obtained in step 215 is reapplied to the pressed sheet to enhance the tobacco flavor of the sheet. Other flavorings may also be included at this stage.

[0065] The sheet is dried as it passes through the drum in step 255 and is further cut into reconstituted tobacco products and packaged in step 260 according to manufacturing requirements.

[0066] Figure 3 A schematic diagram of another method 300 of making a fire-resistant reconstituted tobacco component is shown.

[0067] Instead of extracting tobacco essence / flavor from the raw tobacco leaves, the tobacco leaves are ground into microfibers and / or nanofibers as dried leaves in step 305. The tobacco material is ground into microfibers having an average diameter of between 60 and 400 μm, preferably between 60 and 200 μm, and / or nanofibers having an average diameter of between 50 and 500 nanometers, preferably between 50 and 100 nm. Optionally, the tobacco material (particularly tobacco stems) can be pre-treated using steam explosion to obtain nanofibers.

[0068] Similar to method 200, the tobacco material can be bleached to remove lignin from the tobacco material before or after the grinding step 305. The ground tobacco fibers can also optionally be passed through a disc refiner.

[0069] After the tobacco is ground into fibers, then in step 310 according to the above reference Figure 1A The first grafting process 100 or the second grafting process 150 described in 1B is to perform a fire-resistant treatment on the ground tobacco fibers.

[0070] Then treated tobacco fiber is made slurry.In step 315, treated tobacco fiber-treatment solution mixture is further combined / mixed in another kind of aqueous treatment solution of water, adhesive (as guar gum), pectin and wetting agent to prepare slurry.Especially, wetting agent is selected from the group of following composition: vegetable glycerin, propylene glycol, trimethylene glycol, ethanol and combination thereof.Slurry typically has 8%wt or adhesive content still less of the solids content (fiber) of 15 to 30%wt and total solids content.The weight ratio of tobacco and adhesive is preferably between 50: 1 to 10: 1.

[0071] In step 320, the slurry is degassed and cast into one or more tobacco sheets in step 325. The casting step 325 is typically performed at 20° C. to 100° C. After casting, the tobacco sheets are dried in step 330 to ensure that excess moisture has been removed, whereupon the tobacco sheets are further processed (e.g., cut into shapes and packaged) in step 335.

[0072] As will be appreciated by those skilled in the art, there are several different processes that can be used to make reconstituted tobacco. The main three processes are papermaking (see Figure 2 Described as method 200), slurry type (reference Figure 3 For each process, the refractory / grafting process can be integrated at the beginning of the process. It can be a batch process or a continuous process.

[0073] Figure 4 A schematic diagram of another method 400 of making a fire-resistant reconstituted tobacco component is shown.

[0074] Similar to reference Figure 3 In the described slurry-based method 300, dry tobacco raw material (e.g., tobacco leaves) is ground into microfibers and / or nanofibers in step 405. The tobacco material is ground into microfibers having an average diameter of between 60 and 400 µm, preferably between 60 and 200 µm, and / or nanofibers having an average diameter of between 50 and 500 nm, preferably between 50 and 100 nm. Optionally, the tobacco material (particularly tobacco stems) can be pre-treated using steam explosion to obtain nanofibers.

[0075] Similar to the above-described methods 200, 300, the tobacco material may be bleached to remove lignin from the tobacco material before or after the grinding step 405. The ground tobacco fibers may also optionally be passed through a disc refiner.

[0076] In step 410, after the tobacco leaves and / or stems are ground into fibers, the fibers are then ground according to the above references. Figure 1A The first grafting process 100 or the second grafting process 150 described in 1B is to perform a fire-resistant treatment on the ground tobacco fibers.

[0077] After the grafting process, in step 415, with another kind of aqueous treatment solution combination of treated tobacco fiber-treatment solution mixture and water, adhesive (as guar gum), pectin and wetting agent.Especially, wetting agent is selected from the group of free following composition: vegetable glycerine, propylene glycol, trimethylene glycol, ethanol and combination thereof.New mixture typically has 8%wt or adhesive content still less of the solid content (fiber) of 15 to 30%wt and total solids content.The weight ratio of tobacco and adhesive is preferably between 50: 1 to 10: 1.New mixture is experienced extrusion process in step 420, wherein mixture is extruded in a pair of rollers.When mixture is extruded, can from mixture during extrusion process, extract or extract out excess liquid (it can comprise treatment solution and / or aqueous adhesive solution), make the mixture of extrusion have predetermined moisture level / scope.

[0078] In step 425, the mixture of extrusion passes this pair of rollers to form the laminated sheet of reconstituted tobacco / RTB.Should be understood that when the mixture of extrusion passes rollers, when the laminated sheet forms, other liquid can be extracted from the mixture or squeezed out so that the laminated sheet of the winding of reconstituted tobacco has other predetermined moisture level / scope.Alternatively, rollers can be heated, or drying or heating of another form can be used to further dry the laminated sheet when the laminated sheet forms.After forming the laminated sheet of reconstituted tobacco, or even when the laminated sheet leaves rollers, according to manufacture or design requirements, the laminated sheet is cut into the laminated RTB sheet.

[0079] In step 430 , the laminated reconstituted tobacco slices are further dried to ensure that excess moisture has been removed so that the laminated slices of reconstituted tobacco sheet material can be further processed (eg, packaged or incorporated into consumable products).

[0080] The nanofiber reconstituted tobacco production process begins with the manufacturer grinding the tobacco and then removing sand and other non-tobacco materials before making tobacco sheets. Some nanofiber manufacturing technologies include:

[0081] - Splitting of bicomponent fibers, which involves removing one polymer from island-in-the-sea (or citrus segment) spun fibers;

[0082] - meltblowing, which involves stretching a polymer melt using jets of hot air;

[0083] - physical stretching, which involves physically stretching the polymer solution;

[0084] - flash spinning, which involves simultaneous heating and pressurization of a polymer fluid;

[0085] - Phase separation, which involves the formation of fibers by inducing phase separation of a solution;

[0086] - self-assembly, which involves the self-organization of molecules in solution;

[0087] - solvent dispersion, which involves shear-enhanced solvent precipitation in a nonsolvent;

[0088] - centrifugal spinning, which involves stretching the spinning fluid using centrifugal force;

[0089] - hydrothermal, which involves forming the fibers in a hydrothermal solution; and

[0090] -Electrospinning, which involves stretching a solution through a high electric field.

[0091] The papermaking process (method 200) begins with a process similar to some nanofiber technologies, where the tobacco is ground and mixed with water. Grafting then occurs immediately after the grinding process, and the tobacco is then mixed with water. The tobacco fiber material becomes the paper we mentioned earlier. Once the paper is laminated, the water mixture is sprayed onto the sheets to add back the components.

[0092] In the slurry-type process (method 300), the tobacco fiber material and soluble material are never separated. Instead, they are both mixed into water to create a slurry. The grafting process occurs before the slurry preparation step. This slurry is spread and water evaporated from it to produce a reconstituted tobacco sheet.

[0093] In the lamination method (method 400), the tobacco fiber material and the soluble material are not separated, similar to the slurry method 300. However, instead of spreading the slurry as in the slurry method 300, a mixture of treated tobacco fibers and an aqueous solution of a binder, pectin, humectant, etc. is extruded and then laminated into one or more reconstituted tobacco sheets. As will be appreciated, excess moisture can be extracted from the mixture during the extrusion process and rolling / lamination process. The laminated reconstituted tobacco or RTB slices are then dried to the desired moisture level.

[0094] Figure 5An exemplary heated tobacco stick (HTS) 500 is shown, comprising an aerosol-generating substrate 510 comprising a reconstituted tobacco component wrapped in cigarette paper according to the present disclosure. The cigarette paper may also be fire-resistant cigarette paper. The HTS 500 further comprises a mouth-end section 520 located downstream of the aerosol-generating substrate 510, towards which aerosol generated during use flows. The mouth-end section 520 may comprise a plurality of sections, including one or more of a filter plug, a central channel or aperture, a support tube, and an aerosol-cooling section. The mouth-end 520 may comprise a plurality of sections, including one or more of a filter plug, a central aperture, a support tube, an aerosol-cooling section, and / or a mouthpiece. The mouth-end 520 is located downstream of and preferably adjacent to the aerosol-generating substrate 510 of the aerosol-generating article 500, such that, during use, aerosol generated from the aerosol-generating substrate 510 upon application of heat flows through the mouth-end 520 for inhalation by a user. In some examples, the mouth end 520 may include a cooling section, which may be a paper tube or a section comprising a rolled polylactic acid sheet. In other examples, the mouth end 520 may include a first central hole having a first inner diameter adjacent to the downstream end of the tobacco component, a second central hole having a second inner diameter adjacent to the downstream end of the first central hole, and a mouthpiece adjacent to the downstream end of the second central hole. In this case, the first inner diameter is smaller than the second inner diameter. The first inner diameter may range from 1.5 mm to 4.5 mm, and the second diameter may range from 3.5 mm to 6.0 mm. In another example, the mouth end 520 may include a central hole having an inner diameter adjacent to the downstream end of the tobacco component, an aerosol cooling section adjacent to the downstream end of the central hole, and a mouthpiece adjacent to the downstream end of the aerosol cooling section. The inner diameter of the central hole may range from 1.5 mm to 4.5 mm. The aerosol cooling section may be a paper tube or a section comprising a rolled polylactic acid sheet. The above examples should not limit the present invention. As will be apparent from the overall disclosure, the mouth end 520 may combine multiple segments in different ways to provide the HTS 500, and may also include an upstream element (e.g., a tobacco component of the aerosol-generating article 500, i.e., the aerosol-generating substrate 510), upstream of, and preferably adjacent to, the tobacco component of the aerosol-generating article 500 (i.e., the aerosol-generating substrate 510). Figure 5 (not shown) The upstream element can be a filter plug made of cellulose acetate with or without a central hole, a paper filter with or without a central hole, or a combination thereof. Preferably, the upstream element is wrapped in fire-resistant cigarette paper along with the tobacco component. In some other examples, the fire-resistant cigarette paper may only wrap the upstream element. In this case, the tobacco component is wrapped in conventional cigarette paper that does not have fire-resistant properties.

Claims

1. A method for producing a fire-resistant reconstituted tobacco component, the method comprising the following steps: grinding tobacco material to produce ground tobacco fibers; treating the ground tobacco fibers by applying a treatment solution comprising a donor of phosphorus groups, wherein the donor of phosphorus groups comprises a phosphoinositide moiety; heating the treated tobacco fibers to obtain phosphorus-treated tobacco fibers; as well as The phosphorus-treated tobacco fibers are processed to produce the fire-resistant reconstituted tobacco component.

2. The method according to claim 1, wherein These ground tobacco fibers contain microfibers having an average diameter of less than 400 μm and / or nanofibers having an average diameter of less than 500 nm.

3. A method as claimed in any preceding claim, wherein The treatment solution comprises 0.1 to 20%, preferably 3 to 10% by weight of the phosphoinositide derivative, based on the total weight of the treatment solution.

4. The method according to claim 3, wherein: The phosphoinositide derivatives include phytic acid.

5. The method according to claim 3 or 4, wherein: The treatment solution comprises 1 to 40% by weight, preferably between 10 and 20% by weight, of urea based on the total weight of the treatment solution.

6. A method as claimed in any preceding claim, wherein The ratio of ground tobacco fiber to treatment solution is between 1:1 and 1:10, most preferably 1:

5.

7. A method as claimed in any preceding claim, wherein Treatment of these ground tobacco fibers includes a soaking process or a spraying process.

8. The method of claim 7, wherein the ground tobacco fibers are treated by soaking, The treatment of the ground tobacco fibers further comprises a drying step carried out after the soaking process, said drying step being achieved under atmospheric conditions for between 5 minutes and 8 hours, preferably between 15 min and 30 min, and at a temperature in the range of 15°C to 60°C, preferably in the range of 40°C to 60°C, and wherein the moisture content of the treated tobacco fibers after the drying step ranges between 5% and 20% by weight of the total weight of the treated ground tobacco fibers.

9. A method as claimed in any preceding claim, wherein The treated tobacco fibers are heated at 140°C to 200°C.

10. The method of any preceding claim, further comprising, before applying the treatment solution, the step of applying steam explosion to the ground tobacco fibers to obtain nanofibers having an average diameter of less than 500 nm.

11. A method according to any preceding claim, further comprising the step of refining the ground tobacco fibres.

12. The method according to any preceding claim, further comprising, before the grinding step, the step of: mixing tobacco leaves with water to form a tobacco blend; and dehydrating the tobacco mixture to obtain a tobacco concentrate and the tobacco material for grinding, wherein the tobacco concentrate is recombined with the phosphorus-treated tobacco fibers in the processing step.

13. A fire resistant reconstituted tobacco component comprising 0.1% to 10%, preferably 0.5% to 3% by weight of phosphorus groups based on the total weight of the fire resistant reconstituted tobacco component, and wherein the phosphorus groups comprise phosphoinositide moieties.

14. The fire-resistant reconstituted tobacco component according to claim 13, wherein The phosphorus groups are covalently grafted to the ground tobacco fibers of the reconstituted tobacco component.

15. The fire-resistant reconstituted tobacco component according to claim 13 or 14, comprising: Ground tobacco fibers comprising microfibers having an average diameter of less than 400 μm and / or nanofibers having an average diameter of less than 500 nm.

16. An aerosol-generating article for use with a heat-not-burn aerosol-generating device, the aerosol-generating article comprising an aerosol-generating substrate comprising tobacco material wrapped in cigarette paper to form a tobacco rod, the tobacco material containing the fire-resistant reconstituted tobacco component according to claims 13 to 15.

Images