Method and apparatus for producing a cast sheet for smoking articles or aerosol generating articles

Abstract

A method and an apparatus for producing a cast sheet for smoking articles or aerosol generating articles. The method comprising: mixing ingredients of a recipe and water to form a slurry mixture (M); feeding the slurry mixture (M) to a casting box (15); casting the slurry mixture (M) on a surface to form a cast sheet (S). The method further comprises: heating the slurry mixture (M) to a high temperature (Th) greater than 60°C and keeping the high temperature (Th) of the slurry mixture (M) for a time period (Δth) such to eliminate at least part of organisms in said slurry mixture (M). Heating is performed while the slurry mixture (M) flows in a heated conduit (28) towards the casting box (15).

Description

[0001] PMP1P42WO FTR4092 PCT

[0002] METHOD AND APPARATUS FOR PRODUCING A CAST SHEET FOR SMOKING ARTICLES OR AEROSOL GENERATING ARTICLES

[0003] The present disclosure relates to a method and an apparatus for producing a cast sheet for smoking articles or aerosol generating articles.

[0004] Cast sheets for smoking articles are known in the art and may be employed in the manufacturing of traditional smoking articles, which are ignited at one end causing them to smoulder, and of aerosol-generating articles or heat-not-burn cigarettes, in which an aerosol-generating substrate is heated rather than combusted. In the traditional smoking articles, the cast sheet may be a reconstituted tobacco leaf which may be used in tobacco blends in combination with other tobacco leaves. For instance, the reconstituted tobacco leaf may be shredded and mixed with other leaves to obtain a resulting tobacco blend intended to be ignited and smoked. In the aerosol-generating articles, the cast sheet may be a sheet of the abovementioned aerosol-generating substrate. For instance, the aerosolgenerating substrate sheet is crimped, gathered, wrapped in a rod and cut in aerosolgenerating substrate plugs intended to release volatile compounds by heat transfer from a heat source of an aerosol-generating system.

[0005] Currently, a cast sheet is prepared by casting a slurry on a moving belt through a casting box. For instance, a tobacco slurry is transformed into tobacco cast leaf by the following operations: the tobacco slurry (tobacco powder, water, glycerine, fibres and binders) is manufactured in a tank, the tobacco slurry is then poured into an open-air casting box having an exit at its bottom, an exit height is controlled by a knife which cast the exiting tobacco slurry at a determined thickness on a moving conveyor (e.g. a metal belt), the tobacco slurry is then progressively dried to become tobacco cast leaf.

[0006] Documents WO2016096963A1, W02016050471 and WO2017089589 disclose methods for the preparation of tobacco slurries and casting of the slurries through casting boxes to form the sheets.

[0007] Document US2011220135A1 discloses a method for making dissolvable tobacco film strips, comprising: forming a homogeneous slurry mixture of a tobacco component, a binder, a humectant and a flavorant and casting the slurry to form a film, drying the film, and cutting the film into film strips. The slurry is cast via an apparatus comprising a mixing vessel, a hopper, a carrier tape. The temperature of the slurry in the mixing vessel is controlled through a heater to control the viscosity of the slurry. The slurry of the tobacco could be heated to pasteurize the tobacco.

[0008] Document WO8100001 A1 discloses a process for making cast film from tobacco material in which tobacco blend is mixed and diluted with water to form a watery slurry andPMP1P42WO FTR4092 PCT

[0009] the slurry is cast on an endless belt. The slurry, after dilution and before casting, is heated at 65°C.

[0010] Document CN108523207A discloses a method for maintaining the freshness of materials in a papermaking method reconstituted tobacco production system, in which tobacco raw materials are first extracted with water, then dry materials are made into slurry and then paper-made into a sheet. The slurry in a pulping tank is subjected to online physical sterilization treatment using one or more of treatment methods such as microwave, ultrasonic, ultraviolet and high temperature.

[0011] In this technical field, it would be desirable to have a method and an apparatus for producing a cast sheet for smoking articles or aerosol generating articles capable of improving the overall quality of the manufactured smoking articles and aerosol generating articles.

[0012] It would desirable to have a method and an apparatus for producing a cast sheet for smoking articles or aerosol generating articles capable of improving the taste and aroma perceived by the final consumer and that result safer for the final consumer.

[0013] It would desirable to have a method and an apparatus able to effectively eliminate at least part of organisms in the slurry, such as bacteria, yeasts and molds, that could affect properties of the final smoking articles and aerosol generating articles.

[0014] It would desirable to have a method and an apparatus capable of eliminating the cited organism during the continuous production process of the slurry.

[0015] The present disclosure relates to a method of producing a cast sheet for smoking articles or aerosol generating articles, the method comprising: mixing ingredients of a recipe and water to form a slurry mixture; feeding the slurry mixture to a casting box; casting the slurry mixture on a surface to form a cast sheet. The method further comprises: heating the slurry mixture to a high temperature, optionally greater than 60°C, and keeping the high temperature of the slurry mixture for a time period such to eliminate at least part of organisms in said slurry mixture; wherein heating is performed while the slurry mixture flows in a heated conduit towards the casting box.

[0016] The present disclosure relates to an apparatus for producing a cast sheet for smoking articles or aerosol generating articles, said apparatus being configured to carry out a method of producing a cast sheet for smoking articles or aerosol generating articles. The method comprises: mixing ingredients of a recipe and water to form a slurry mixture; feeding the slurry mixture to a casting box; casting the slurry mixture on a surface to form a cast sheet. The method further comprises: heating the slurry mixture to a high temperature, optionally greater than 60°C, and keeping the high temperature of the slurry mixture for a time period such to eliminate at least part of organisms in said slurry mixture; whereinPMP1P42WO FTR4092 PCT

[0017] heating is performed while the slurry mixture flows in a heated conduit towards the casting box.

[0018] The present disclosure relates an apparatus for producing a cast sheet for smoking articles or aerosol generating articles, the apparatus comprising: at least one of a mixer configured for mixing ingredients of a recipe and water to form a slurry mixture and a slurry container configured to hold the slurry mixture; a casting box in fluid communication with the mixer or with the slurry container to receive the slurry mixture; a surface located under the casting box and configured to receive the slurry mixture from said casting box and to form a cast sheet on said surface. The apparatus further comprises a heating device operatively located between the mixer or the slurry container and the casting box and configured to eliminate at least part of organisms in the slurry mixture. The heating device comprises: a heated conduit in fluid communication with the mixer or the slurry container and the casting box, the slurry mixture flowing across said heated conduit from the mixer or the slurry container towards the casting box; a heater operatively active on said heated conduit to heat the slurry mixture flowing towards the casting box to a high temperature, optionally greater than 60°C.

[0019] The present disclosure relates to a process of manufacturing smoking articles or aerosol generating articles, the process comprising a method of producing a cast sheet for smoking articles or aerosol generating articles. Said method comprises: mixing ingredients of a recipe and water to form a slurry mixture; feeding the slurry mixture to a casting box; casting the slurry mixture on a surface to form a cast sheet. The method further comprises: heating the slurry mixture to a high temperature, optionally greater than 60°C, and keeping the high temperature of the slurry mixture for a time period such to eliminate at least part of organisms in said slurry mixture; wherein heating is performed while the slurry mixture flows in a heated conduit towards the casting box.

[0020] The process of manufacturing smoking articles or aerosol generating articles may comprise: gathering the cast sheet and wrapping in a wrapper to form an endless rod; cutting the endless rod in a plurality of discrete rods; joining the discrete rods to other components to form a plurality of smoking articles or aerosol generating articles.

[0021] The present disclosure relates to a smoking article or an aerosol generating article manufactured through said process of manufacturing smoking articles or aerosol generating articles.

[0022] The inventor found that the method and apparatus of the invention allow to effectively eliminate organisms in the slurry, such as bacteria, yeasts and molds, that could affect properties of the cast sheet and thus of the final smoking articles and aerosol generating articles. Indeed, the high temperature destroys or deactivates microorganisms andPMP1P42WO FTR4092 PCT

[0023] enzymes that could be harmful and / or that could affect the flavour and aroma perceived by the consumer and the overall quality of the final smoking articles and aerosol generating articles. The resulting smoking articles and aerosol generating articles are also safer for the consumers.

[0024] The inventor found that, by controlling microbial activity, the cast sheets and the final smoking articles and aerosol generating articles have an extended shelf life, reducing waste and economic losses.

[0025] The inventor found that, since heating is performed while the slurry mixture flows in the heated conduit, the method and apparatus of the invention avoid storing for a long time the slurry in a container that could cause an unwanted fermentation of the slurry due to the growth of said microorganisms which thrive in high moisture environments.

[0026] The inventor found that heating performed while the slurry mixture flows in the heated conduit allow to eliminate the organisms without affecting the production times.

[0027] The inventor found that heating performed while the slurry mixture flows in the heated conduit allows avoiding slowdowns and stagnation of the slurry and allows implementing the heating in continuous production of the cast sheet. This also mitigates the need of purging and cleaning the system frequently, thus saving machine down time and material costs.

[0028] The slurry mixture may have a water content from 65 percent to 90 percent.

[0029] In some embodiments, the high temperature and the time period are such to achieve a pasteurization of the slurry mixture.

[0030] Pasteurization either destroys or deactivates microorganisms and enzymes including vegetative bacteria and the inventor found that pasteurization allows fulfilling the stringent regulatory standards for tobacco products, ensuring compliance with health and safety guidelines.

[0031] The high temperature may be from 70°C to 75°C, optionally of 72°C. The time period may be from 15 seconds to 30 seconds.

[0032] The inventor found that these ranges of temperature and time, which match with the HTST (High-Temperature-Short-Time) pasteurization, allow to inactivate undesirable microorganisms, to kill vegetative pathogens and to preserve color, texture, aroma and flavor of the cast sheet that could be undermined by higher temperatures.

[0033] In some embodiments, heating the slurry mixture comprises: heating the heated conduit so that the slurry mixture is heated by conduction through said heated conduit. The heater may be external to said heated conduit to heat a wall of the heated conduit and to heat the slurry mixture by conduction.PMP1P42WO FTR4092 PCT

[0034] In some embodiments, heating the heated conduit comprises: transferring heat from a source of hot fluid to the heated conduit. The hot fluid may be water. A temperature of the hot fluid may be from 70°C to 75°C.

[0035] In some embodiments, the hot fluid is circulated in a pipe coupled to the heated conduit. The heater may comprise a source of a hot fluid and a pipe connected to the source of hot fluid and coupled to the wall of the heated conduit. The pipe may form a closed circuit with the source of hot fluid. The pipe may form a closed circuit with a hot fluid pump. The pipe may be coiled around the heated conduit. The hot fluid across the pipe may have a temperature from 70°C to 75°C. The source of a hot fluid may comprise a steam chamber.

[0036] The inventor found that this configuration promotes an efficient and rapid heat transfer without contaminating the slurry mixture.

[0037] In some embodiments, keeping the high temperature of the slurry mixture for the time period is carried out while the slurry mixture flows in the heated conduit. A length of the heated conduit may be such to keep the slurry mixture at said high temperature for a time period.

[0038] In some embodiments, after heating the slurry mixture in the heated conduit, the slurry mixture is held in a slurry storage tank before feeding to the casting box. An amount of slurry mixture may be held in the slurry storage tank while the slurry mixture continuously flows in and out of the slurry storage tank which works as a buffer. The slurry storage tank may present an inlet connected to the heated conduit and an outlet connected to the casting box.

[0039] The slurry mixture in the slurry storage tank may be kept at the high temperature. In some embodiments, the heating device further comprises a slurry storage tank placed downstream of the heated conduit and connected to said heated conduit. The time period may be a time the slurry mixture dwells in the slurry storage tank.

[0040] The inventor found that the slurry storage tank works as a buffer and provides heat to the slurry mixture to keep the high temperature for the required time period.

[0041] In some embodiment which are not part of the present invention but may be subject of a divisional application, the slurry mixture is heated and kept at the high temperature for the time period in the slurry storage tank instead of in the heated conduit.

[0042] In some embodiments, the heating device further comprises an auxiliary heater operatively active in said slurry storage tank to keep the slurry mixture in the storage tank at said high temperature for said time period.

[0043] In some embodiments, keeping the slurry mixture in the slurry storage tank at the high temperature comprises: injecting steam in the slurry storage tank. The auxiliary heater may comprise a source of steam connected to an inner chamber of the slurry storage tank, said inner chamber holding the slurry mixture. The source of steam may be connected to anPMP1P42WO FTR4092 PCT

[0044] upper empty part of the inner chamber. The steam may be injected in an upper empty part of the slurry storage tank.

[0045] The inventor found that the steam supplements the thermal energy provided by the hot fluid and ensures that the slurry mixture attains the required temperature for the required time to eliminate said organisms. Steam injection in the upper empty part of the inner chamber further achieves the following objectives: preventing microbial growth on the internal walls of the slurry storage tank; preventing the slurry from drying on the walls creating residues that had to be removed; preventing the free slurry surface from drying and formation of portions of slurry with different densities that could generate issues when casting.

[0046] In some embodiments, the heating device comprises a temperature controller configured to control the heater and to bring the slurry mixture up to the high temperature. The temperature controller may be configured to control the auxiliary heater and to keep the slurry mixture in the storage tank at said high temperature.

[0047] In some embodiments, the temperature controller comprises: at least one temperature sensor configured to sense a temperature of the slurry mixture in at least one of the heated conduit and the slurry storage tank. The temperature controller may also comprise: a feedback mechanism configured to command the heater and / or the auxiliary heater in order to adjust the temperature of the slurry mixture in at least one of the heated conduit and the slurry storage tank.

[0048] The inventor found that the thermal environment in the heating device is continuously monitored and regulated by the temperature controller that adjusts the heat input dynamically, ensuring that the slurry mixture is brought and maintained at the required high temperature for the designated time period.

[0049] In some embodiments, once the time period is elapsed and before feeding to the casting box, the slurry mixture is cooled to a low temperature. A cooling device may be operatively located downstream of the heating device and upstream of the casting box. The cooling device may be configured to lower the temperature of the slurry mixture coming from the heating device to a low temperature. The low temperature may be lower than 15°C, preferably lower than 10°C, optionally from 4°C to 15°C, optionally from 4°C to 10°C, optionally from 4.4°C to 7.2°C. A cooling time taken to cool down the slurry mixture to the low temperature may be from 5 seconds to 10 seconds. The cooling device may be configured to cool down the slurry mixture to the low temperature in a cooling time from 5 seconds to 10 seconds.

[0050] The inventor found that the quick decrease of the slurry temperature downstream of the heating device prevents thermal degradation and preserves the integrity of the slurryPMP1P42WO FTR4092 PCT

[0051] mixture. In addition, cooling stabilizes the slurry mixture temperature upstream of the casting box, assures consistent rheological characteristics of the slurry mixture and generates hostile conditions for microbiological growth.

[0052] In some embodiments, cooling the slurry mixture comprises: making the slurry mixture to cross a cooled conduit and cooling the cooled conduit so that the slurry mixture is cooled by conduction through said cooled conduit. The cooling device may comprise: a cooled conduit in fluid communication with the heating device, the slurry mixture flowing across said cooled conduit from the heating device towards the casting box.

[0053] The inventor found that cooling performed while the slurry mixture flows in the cooled conduit allows avoiding slowdowns and stagnation of the slurry and allows implementing the cooling in continuous production of the cast sheet.

[0054] In some embodiments, the cooling device comprises: a cooler operatively active on said cooled conduit to cool the slurry mixture flowing towards the casting box. The cooler may be external to said cooled conduit to cool a wall of the cooled conduit and to cool the slurry mixture by conduction.

[0055] In some embodiments, cooling the cooled conduit comprises: transferring heat from the cooled conduit to a source of cold fluid. The cooler may comprise a cold fluid and a pipe connected to the source of cold fluid and coupled to the wall of the cooled conduit. The cold fluid may be circulated in the pipe coupled to the cooled conduit. The pipe may be coiled around the cooled conduit. The cold fluid may be water. A temperature of the cold fluid may be lower than 15°C, preferably lower than 10°C, optionally from 4°C to 15°C, optionally from 4°C to 10°C, optionally from 4.4°C to 7.2°C.

[0056] The inventor found that the cold fluid circulating in the pipe absorbs the residual heat from the slurry mixture and achieves a quick and controlled cooling process which brings the slurry mixture to the desired low temperature.

[0057] In some embodiments, after keeping the slurry mixture to high temperature, said method comprises: storing the slurry mixture in a silo before feeding to the casting box. A silo may be operatively located between the heating device and the casting box and may be configured for storing the slurry mixture before feeding to the casting box. The slurry mixture may be stored in the silo for a storing time from 10 to 90 min. A slurry pump may be placed downstream of the silo and may be configured to pump the slurry mixture towards the casting box.

[0058] In some embodiments, the apparatus comprises both the mixer and the slurry container. The slurry container may be located between the mixer and the heating device. The mixer may be a batch mixer or a continuous mixer.PMP1P42WO FTR4092 PCT

[0059] In some embodiments, the continuous mixer delimits a mixing path and has at least one inlet communicating with the mixing path, the at least one inlet being configured to feed the ingredients and the water into the mixing path, and an outlet located at an end of the mixing path, the outlet being configured to discharge the slurry mixture from the continuous mixer; the continuous mixer being configured to mix the ingredients and the water while advancing said ingredients and water in the mixing path towards the outlet; the continuous mixer comprising at least one mixing tool located in the mixing path and configured to mix the ingredients and the water and to advance the ingredients and the water and the slurry mixture along the mixing path. The at least one mixing tool may be configured to rotate about an axis parallel to the mixing path. The at least one inlet may comprise a plurality of inlets for the ingredients and a water inlet. The mixing path and the axis may be horizontal and the continuous mixer may be a horizontal mixer.

[0060] In some embodiments, the surface moves below the casting box. A belt conveyor may be located below the casting box, wherein the surface is an upper branch of the belt conveyor.

[0061] In some embodiments, a further slurry pump is placed between the slurry container and the heating device and is configured to pump the slurry mixture towards heating device.

[0062] In some embodiments, the ingredients of the recipe comprise tobacco, optionally tobacco particles, optionally grinded tobacco.

[0063] In some embodiments, the ingredients of the recipe comprise: fibers, for instance cellulose fibers, a binder, for instance guar gum or a derivative of cellulose such as carboxymethylcellulose (CMC) and hydroxypropylmethylcellulose (HPMC), and an aerosol forming agent, such as a polyhydric alcohol, for instance triethylene glycol or 1 ,3-butanediol or glycerine.

[0064] The inventor found that the method and apparatus of the invention are particularly effective with tobacco containing products, because bacteria, yeasts, and molds are usually present in the tobacco leaves and may cause unwanted fermentation that may alter taste and aroma.

[0065] As used in the present description, the term “slurry” means a watery mixture of insoluble matter with a water content so high (e.g. 65 percent - 90 percent) that cannot be kneaded or rolled out, as opposed to “dough” which is a mixture that is stiff enough to be kneaded or rolled out.

[0066] As used in the present description, the term “conduit”, for instance referred to the “heated conduit”, means a tube or pipeline along which a slurry flow passes at a certain flow rate through a cross section of said tube or pipeline.PMP1P42WO FTR4092 PCT

[0067] As used in the present description, the term “organism” includes microorganisms such as bacteria, spores, yeasts and molds, that could be harmful and / or that could affect properties of the cast sheet and / or of the final smoking articles and aerosol generating articles.

[0068] As used in the present description, the term “recipe” means a group of ingredients without any limitation concerning the order and the timing in which they are combined with each other and / or with water.

[0069] As used in the present description, the terms “upstream” and “downstream” are used to describe the relative positions of components, or portions of components, of the apparatus in relation to the direction in which a material or materials passes through the apparatus along a given path.

[0070] The invention is defined in the claims. However, below there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0071] EX1. A method of producing a cast sheet for smoking articles or aerosol generating articles, the method comprising:

[0072] mixing ingredients of a recipe and water to form a slurry mixture;

[0073] feeding the slurry mixture to a casting box;

[0074] casting the slurry mixture on a surface to form a cast sheet;

[0075] wherein the method further comprises: heating the slurry mixture to a high temperature greater than 60°C and keeping the high temperature of the slurry mixture for a time period such to eliminate at least part of organisms in said slurry mixture; wherein heating is performed while the slurry mixture flows in a heated conduit towards the casting box. EX2. The method according to EX1 , wherein the high temperature and the time period are such to achieve a pasteurization of the slurry mixture.

[0076] EX3. The method according to EX1 or EX2, wherein the high temperature is from 70°C to 75°C, optionally of 72°C.

[0077] EX4. The method according to any of EX1 to EX3, wherein the time period is from 15 seconds to 30 seconds.

[0078] EX5. The method according to any of EX1 to EX4, wherein heating the slurry mixture comprises: heating the heated conduit so that the slurry mixture is heated by conduction through said heated conduit.

[0079] EX6. The method according to EX5, wherein heating the heated conduit comprises: transferring heat from a source of hot fluid to the heated conduit.PMP1P42WO FTR4092 PCT

[0080] EX7. The method according to EX6, wherein a temperature of the hot fluid is from 70°C to 75°C.

[0081] EX8. The method according to EX6 or EX7, wherein the hot fluid is water.

[0082] EX9. The method according to any of EX6 to EX8, wherein the hot fluid is circulated in a pipe coupled to the heated conduit.

[0083] EX10. The method according to EX9, wherein the pipe is coiled around the heated conduit.

[0084] EX11. The method according to any of EX1 to EX10, wherein keeping the high temperature of the slurry mixture for the time period is carried out while the slurry mixture flows in the heated conduit; and / or wherein the method further comprises: after heating the slurry mixture in the heated conduit, holding the slurry mixture in a slurry storage tank before feeding to the casting box.

[0085] EX12. The method according to EX11, wherein the time period is a time the slurry mixture dwells in the slurry storage tank.

[0086] EX13. The method according to EX12, wherein an amount of slurry mixture is held in the slurry storage tank while the slurry mixture continuously flows in and out of the slurry storage tank which works as a buffer.

[0087] EX14. The method according to any of EX11 to EX13, comprising: keeping the slurry mixture in the slurry storage tank at the high temperature.

[0088] EX15. The method according to EX14, wherein keeping the slurry mixture in the slurry storage tank at the high temperature comprises: injecting steam in the slurry storage tank.

[0089] EX16. The method according to EX15, wherein the steam is injected in an upper empty part of the slurry storage tank.

[0090] EX17. The method according to any of EX1 to EX16, wherein, once the time period is elapsed and before feeding to the casting box, the slurry mixture is cooled to a low temperature.

[0091] EX18. The method according to EX17, wherein the low temperature is lower than 15°C, preferably lower than 10°C, optionally from 4°C to 15°C, optionally from 4°C to 10°C, optionally from 4.4°C to 7.2°C.

[0092] EX19. The method according to EX17 or EX18, wherein a cooling time taken to cool down the slurry mixture to the low temperature is from 5 seconds to 10 seconds.

[0093] EX20. The method according to any of EX17 to EX19, wherein cooling the slurry mixture comprises: making the slurry mixture to cross a cooled conduit and cooling the cooled conduit so that the slurry mixture is cooled by conduction through said cooled conduit.PMP1P42WO FTR4092 PCT

[0094] EX21. The method according to EX20, wherein cooling the cooled conduit comprises: transferring heat from the cooled conduit to a cold fluid.

[0095] EX22. The method according to EX21, wherein the cold fluid is water.

[0096] EX23. The method according to any of EX21 to EX22, wherein the cold fluid is circulated in a pipe coupled to the cooled conduit.

[0097] EX24. The method according to EX23, wherein the pipe is coiled around the cooled conduit.

[0098] EX25. The method according to any of EX21 to EX24, wherein a temperature of the cold fluid is lower than 15°C, preferably lower than 10°C, optionally from 4°C to 15°C, optionally from 4°C to 10°C, optionally from 4.4°C to 7.2°C.

[0099] EX26. The method according to any of EX1 to EX25, wherein the ingredients of the recipe comprise tobacco, optionally tobacco particles, optionally grinded tobacco.

[0100] EX27. The method according to any of EX1 to EX26, wherein the ingredients of the recipe comprise: fibers, for instance cellulose fibers, a binder, for instance guar gum or a derivative of cellulose such as carboxymethylcellulose (CMC) and hydroxypropylmethylcellulose (HPMC), and an aerosol forming agent, such as a polyhydric alcohol, for instance triethylene glycol or 1,3-butanediol or glycerine.

[0101] EX28. The method according to any of EX1 to EX27, wherein the slurry mixture has a water content from 65 percent to 90 percent.

[0102] EX29. The method according to any of EX1 to EX28, wherein, after keeping the slurry mixture to high temperature, said method comprises: storing the slurry mixture in a silo before feeding to the casting box.

[0103] EX30. The method according to EX29, wherein the slurry mixture is stored in the silo for a storing time from 10 to 90 min.

[0104] EX31. An apparatus for producing a cast sheet for smoking articles or aerosol generating articles, the apparatus being configured to carry out the method according to any of EX1 to EX30.

[0105] EX32. An apparatus for producing a cast sheet for smoking articles or aerosol generating articles, the apparatus comprising:

[0106] at least one of a mixer configured for mixing ingredients of a recipe and water to form a slurry mixture and a slurry container configured to hold the slurry mixture;

[0107] a casting box in fluid communication with the mixer or with the slurry container to receive the slurry mixture;

[0108] a surface located under the casting box and configured to receive the slurry mixture from said casting box and to form a cast sheet on said surface;PMP1P42WO FTR4092 PCT

[0109] wherein the apparatus further comprises a heating device operatively located between the mixer or the slurry container and the casting box and configured to eliminate at least part of organisms in the slurry mixture;

[0110] wherein the heating device comprises:

[0111] a heated conduit in fluid communication with the mixer or the slurry container and the casting box, the slurry mixture flowing across said heated conduit from the mixer or the slurry container towards the casting box;

[0112] a heater operatively active on said heated conduit to heat the slurry mixture flowing towards the casting box to a high temperature greater than 60°C.

[0113] EX33. The apparatus according to EX32, wherein the heater is external to said heated conduit to heat a wall of the heated conduit and to heat the slurry mixture by conduction.

[0114] EX34. The apparatus according to EX33, wherein the heater comprises a source of a hot fluid and a pipe connected to the source of hot fluid and coupled to the wall of the heated conduit.

[0115] EX35. The apparatus according to EX34, wherein the pipe is coiled around the heated conduit.

[0116] EX36. The apparatus according to EX34 or EX35, wherein the source of a hot fluid comprises a steam chamber.

[0117] EX37. The apparatus according to any of EX34 to EX36, wherein the hot fluid is water.

[0118] EX38. The apparatus according to any of EX34 to EX37, wherein the pipe forms a closed circuit with the source of hot fluid and, optionally, with a hot fluid pump.

[0119] EX39. The apparatus according to any of EX34 to EX38, wherein the hot fluid across the pipe has a temperature from 70°C to 75°C.

[0120] EX40. The apparatus according to any of EX32 to EX39, wherein a length of the heated conduit is such to keep the slurry mixture at said high temperature for a time period; and / or wherein the heating device further comprises a slurry storage tank placed downstream of the heated conduit and connected to said heated conduit.

[0121] EX41. The apparatus according to EX40, wherein the heating device further comprises an auxiliary heater operatively active in said slurry storage tank to keep the slurry mixture in the storage tank at said high temperature for a time period.

[0122] EX42. The apparatus according to EX41, wherein the auxiliary heater comprises a source of steam connected to an inner chamber of the slurry storage tank, said inner chamber holding the slurry mixture.PMP1P42WO FTR4092 PCT

[0123] EX43. The apparatus according to EX42, wherein the source of steam is connected to an upper empty part of the inner chamber.

[0124] EX44. The apparatus according to any of EX40 to EX43, wherein the slurry storage tank presents an inlet connected to the heated conduit and an outlet connected to the casting box.

[0125] EX45. The apparatus according to any of EX32 to EX44, wherein the heating device comprises a temperature controller configured to control the heater and to bring the slurry mixture up to the high temperature.

[0126] EX46. The apparatus according to EX45 when according to any of EX40 to EX44, wherein the temperature controller is configured to control the auxiliary heater and to keep the slurry mixture in the storage tank at said high temperature.

[0127] EX47. The apparatus according to EX46, wherein the temperature controller comprises: at least one temperature sensor configured to sense a temperature of the slurry mixture in at least one of the heated conduit and the slurry storage tank; a feedback mechanism configured to command the heater and / or the auxiliary heater in order to adjust the temperature of the slurry mixture in at least one of the heated conduit and the slurry storage tank.

[0128] EX48. The apparatus according to any of EX32 to EX47, further comprising a cooling device operatively located downstream of the heating device and upstream of the casting box, the cooling device being configured to lower the temperature of the slurry mixture coming from the heating device to a low temperature.

[0129] EX49. The apparatus according to EX48, wherein the low temperature is lower than 15°C, preferably lower than 10°C, optionally from 4°C to 15°C, optionally from 4°C to 10°C, optionally from 4.4°C to 7.2°C.

[0130] EX50. The apparatus according to EX48 or EX49, wherein the cooling device is configured to cool down the slurry mixture to the low temperature in a cooling time from 5 seconds to 10 seconds.

[0131] EX51. The apparatus according to any of EX48 to EX50, wherein the cooling device comprises: a cooled conduit in fluid communication with the heating device, the slurry mixture flowing across said cooled conduit from the heating device towards the casting box.

[0132] EX52. The apparatus according to EX51, wherein the cooling device comprises: a cooler operatively active on said cooled conduit to cool the slurry mixture flowing towards the casting box.

[0133] EX53. The apparatus according to EX52, wherein the cooler is external to said cooled conduit to cool a wall of the cooled conduit and to cool the slurry mixture by conduction.PMP1P42WO FTR4092 PCT

[0134] EX54. The apparatus according to EX53, wherein the cooler comprises a source of a cold fluid and a pipe connected to the source of cold fluid and coupled to the wall of the cooled conduit.

[0135] EX55. The apparatus according to EX54, wherein the cold fluid is water.

[0136] EX56. The apparatus according to EX54 or EX55, wherein the cold fluid is circulated in the pipe coupled to the cooled conduit.

[0137] EX57. The method according to any of EX54 to EX56, wherein the pipe is coiled around the cooled conduit.

[0138] EX58. The apparatus according to any of EX54 to EX57, wherein a temperature of the cold fluid is lower than 15°C, preferably lower than 10°C, optionally from 4°C to 15°C, optionally from 4°C to 10°C, optionally from 4.4°C to 7.2°C.

[0139] EX59. The apparatus according to any of EX32 to EX58, further comprising a silo operatively located between the heating device and the casting box and configured for storing the slurry mixture before feeding to the casting box.

[0140] EX60. The apparatus according to EX59, comprising a slurry pump placed downstream of the silo and configured to pump the slurry mixture towards the casting box.

[0141] EX61. The apparatus according to any of EX32 to EX60, comprising both the mixer and the slurry container, wherein the slurry container is located between the mixer and the heating device.

[0142] EX62. The apparatus according to any of EX32 to EX61, wherein the mixer is a batch mixer or a continuous mixer.

[0143] EX63. The apparatus according to EX62, wherein the continuous mixer delimits a mixing path and has at least one inlet communicating with the mixing path, the at least one inlet being configured to feed the ingredients and the water into the mixing path, and an outlet located at an end of the mixing path, the outlet being configured to discharge the slurry mixture from the continuous mixer; the continuous mixer being configured to mix the ingredients and the water while advancing said ingredients and water in the mixing path towards the outlet; the continuous mixer comprising at least one mixing tool located in the mixing path and configured to mix the ingredients and the water and to advance the ingredients and the water and the slurry mixture along the mixing path.

[0144] EX64. The apparatus according to EX63, wherein the at least one mixing tool is configured to rotate about an axis parallel to the mixing path.

[0145] EX65. The apparatus according to EX63 or EX64, wherein the at least one inlet comprises a plurality of inlets for the ingredients and a water inlet.

[0146] EX66. The apparatus according to any of EX63 to EX65, wherein the mixing path and the axis are horizontal and the continuous mixer is a horizontal mixer.PMP1P42WO FTR4092 PCT

[0147] EX67. The apparatus according to any of EX32 to EX66, wherein the surface moves below the casting box; optionally the apparatus comprises a belt conveyor located below the casting box, wherein the surface is an upper branch of the belt conveyor.

[0148] EX68. The apparatus according to EX67, comprising a further slurry pump placed between the slurry container and the heating device and configured to pump the slurry mixture towards heating device.

[0149] EX69. The apparatus according to any of EX32 to EX68, wherein said apparatus is configured to carry out the method according to any of EX1 to EX30.

[0150] EX70. A process of manufacturing smoking articles or aerosol generating articles, comprising the method according to any of EX1 to EX30.

[0151] EX71. The process according to EX70, comprising: gathering the cast sheet and wrapping in a wrapper to form an endless rod; cutting the endless rod in a plurality of discrete rods; joining the discrete rods to other components to form a plurality of smoking articles or aerosol generating articles.

[0152] EX72. A smoking article or an aerosol generating article manufactured through the process according to EX70.

[0153] Examples will now be further described with reference to the figures in which:

[0154] Figure 1 shows an apparatus for producing a cast sheet for smoking articles or aerosol generating articles;

[0155] Figure 2 shows an enlarged part of the apparatus of Figure 1 ;

[0156] Figure 3 is a detailed part of an embodiment of the apparatus of Figure 1 ;

[0157] Figure 4 shows a manufacturing line for producing aerosol-generating article components or smoking article components from the cast sheet;

[0158] Figures 5 and 6 show respectively a longitudinal section and a cross section of an aerosol-generating article component manufactured through the manufacturing line of Figure 4;

[0159] Figure 7 is an exploded view of an aerosol-generating article comprising the aerosolgenerating article component of Figures 4 and 5;

[0160] Figure 8 is a flowchart representing a method of producing a cast sheet for smoking articles or aerosol generating articles.

[0161] An apparatus 100 for manufacturing aerosol-generating article components 101 is shown in Figure 4. The apparatus 100 may be part of a plant, not shown, for manufacturing aerosol-generating articles.

[0162] An overview of the elements and general operation of the apparatus 100 is provided below, demonstrating the use of a cast sheet “S” of an aerosol-generating substrate for making the aerosol-generating article components 101. Subsequently, a detailedPMP1P42WO FTR4092 PCT

[0163] description of an apparatus 1 (shown in Figure 1) and a method (Figure 8) for producing the cast sheet “S” used by the apparatus 100 to create the aerosol-generating article component 101 will be provided.

[0164] Referring to Figure 4, the apparatus 100 includes a reel holder 102 where the cast sheet “S” is coiled in a reel 103.

[0165] An extraction device (not shown) is configured to uncoil the cast sheet “S” from the reel 103, and a conveyor guides the cast sheet “S” along a conveying direction “C,” parallel to its longitudinal dimension. For instance, the conveyor comprises a plurality of motorized rollers and / or one or more motorized belt conveyors located along the conveying direction "C".

[0166] Downstream of the reel holder 102, in the conveying direction “C,” the apparatus 100 comprises a weakening device 104 comprising counterrotating crimping rollers 105 for weakening the sheet of aerosol-generating substrate “S”. Each counterrotating crimping roller 105 is operatively connected to a motor (not shown) for rotation to generate a plurality of substantially parallel ridges or corrugations on the sheet of aerosol-generating substrate “S”.

[0167] Further downstream, the apparatus 100 includes a gathering device 106, a wrapping device 107 and a cutter 108. The gathering device 106 includes a converging tool shaped like a tapered funnel 109, which transitions the cast sheet “S” from a flat configuration (upstream of the gathering device) to a gathered rod-shaped configuration (downstream of the gathering device) as it is conveyed and pulled through the tool.

[0168] The wrapping device 107 is designed to wrap the rod-shaped cast sheet “S” in a wrapper 110 to form a continuous rod 111. The wrapping device 107 comprises a guide cooperating with a feeder of the wrapper 110. The guide, not shown in figure, may comprise a U-shaped channel with additional folding elements configured to close the wrapper 110 around the gathered cast sheet “S”. The feeder of the wrapper 110 is represented as an auxiliary reel holder 112 on which the wrapper 110 is wound in an auxiliary reel 113.

[0169] The cutter 108, such as a rotating blade, is positioned downstream of the wrapping device 107 and is designed to cut the continuous rod 111 into the aerosol-generating article components 101. The aerosol-generating article components 101 may then be joined to other components to form a plurality of smoking articles or aerosol generating articles.

[0170] The apparatus 100 may also include a controller (not shown in the figures) configured to synchronize the operations of the reel holder 102, the weakening device 104, the auxiliary reel holder 112, the conveyor, and the cutter 108.

[0171] One aerosol-generating article component 101 comprising the gathered cast sheet “S” in the wrapper 110 is shown in figures 5 and 6.PMP1P42WO FTR4092 PCT

[0172] An aerosol-generating article 200 comprising one aerosol generating article component 101 is shown in the exploded view of figure 6. The aerosol-generating article 200 comprises (from left to right in figure 7): a front plug 203 (solid plug), the aerosolgenerating article component 101, a tubular plug 205 (hollow plug, for instance of cellulose acetate), a fine tubular plug 206 (similar to the tubular plug 205 but with a thinner wall) and a filter plug 207 (mouthpiece filter, usually made of tow). Each plug has a wrapping of its own helping to contain properly their content. A tipping paper 208 connects the filter plug 207 to the rest of the plugs, and the front plug 203, aerosol-generating article component 101 , tubular plug 205 and fine tubular plug 206 are wrapped together into a wrapping paper 209. The tubular plug 205 and fine tubular plug 206 are cooling plugs configured to cool down the aerosol formed by heating the aerosol-generating article component 101.

[0173] The apparatus 1 for producing the cast sheet “S” is further described with reference to figures 1 , 2 and 3. As previously mentioned, the apparatus 1 for producing the cast sheet “S” is configured to produce the cast sheet “S”, which is subsequently reeled and used by the apparatus 100 for making the aerosol-generating article components 101.

[0174] The apparatus 1 comprises a mixer 2 configured for mixing ingredients of a recipe and water to form a slurry mixture “M”. The mixer 2 may be a batch mixer as represented schematically in Figure 1 or may be a continuous horizontal mixer, as schematically depicted in Figure 2.

[0175] The continuous horizontal mixer 2 delimits a mixing path 3 and one inlet 4 communicating with the mixing path 3. The inlet 4 is connected to containers of grinded tobacco 5, cellulosic fibers 6, guar 7, glycerin 8 and water 9. The inlet 4 is configured to feed the ingredients (grinded tobacco 5, cellulosic fibers 6, guar 7, glycerin 8) and the water 9 into the mixing path 3. In other embodiments, not shown, the continuous horizontal mixer 2 comprises a plurality of inlets for the ingredients and a water inlet.

[0176] An outlet 10 is located at an end of the mixing path 3 and is configured to discharge the slurry mixture “M” from the continuous mixer 2. The continuous mixer 2 comprises a mixing tool 11, like a mixing screw (represented schematically in Figure 3), located in the mixing path 3, rotating about a horizontal axis parallel to the mixing path 3 and configured to mix the ingredients and the water and to advance the ingredients and the water and the slurry mixture “M” along the mixing path 3 towards the outlet 10. The slurry mixture “M” has a high-water content, for instance of 80 percent by weight.

[0177] The outlet 11 is connected through a piping and in sequence to a heating device 12 followed by a cooling device 13, followed by a silo 14 and then to a casting box 15.PMP1P42WO FTR4092 PCT

[0178] A belt conveyor 16 is located below the casting box 15. An upper branch of the belt conveyor 16 present a surface configured to receive from the casting box 15 the slurry mixture “M” and to form the cast sheet “S”.

[0179] As better illustrated in Figure 2, the belt conveyor 16 comprises a first drum 17, a second drum 18 and a belt 19 forming a closed loop around the first drum 17 and the second drum 18. A conveyor motor, not shown, is connected to the first drum 17 to move an upper branch of the belt 19 along a conveying direction.

[0180] The casting box 15 has a top opening and a bottom opening. The bottom opening is close to and faces a portion of the upper branch of the belt 19 located at the first drum 17. The casting box 15 comprises a casting blade 20 delimiting a slot 21 together with the upper branch of the belt 19. The casting blade 20 is an element having one edge that is intended to come into contact with the slurry mixture “M”. Said edge may have a sharp and knife-like shape or a rectangular or a rounded shape. The slurry mixture “M” crosses the slot and is deposited on the surface as the cast sheet “S”. The cast sheet “S” crosses a drying unit 22, such as an oven, to remove excess moisture and to solidify said cast sheet “S” that is then coiled on a reel holder 23 in a reel 24.

[0181] A slurry pump 25 is placed downstream of the silo 14 and is configured to pump the slurry mixture “M” towards the casting box 15 (Figure 1). In Figures 1 and 3, a further slurry pump 26 is placed between the mixer 2 and the heating device 12 and is configured to pump the slurry mixture “M” towards heating device 12.

[0182] The embodiment of Figure 3 comprises also a slurry container 27 configured to hold the slurry mixture “M”, like a buffer, before flowing to the heating device 12. The slurry container 27 is located between the mixer 2 and the further pump 26.

[0183] The heating device 12 is configured to eliminate at least part of organisms in the slurry mixture “M” coming from the mixer 2 or from the slurry container 27 and flowing towards the casting box 15.

[0184] The heating device 12 comprises a heated conduit 28 having an inlet in fluid communication with the further pump 26 (Figure 3). A heater 29 is operatively active on the heated conduit 28 to heat the slurry mixture “M” flowing across the heated conduit 28. The heater 29 comprises a steam chamber 30 connected to a pipe 31 forming a closed circuit. A portion of the pipe 31 is coiled around the heated conduit 28 and is coupled to a wall of the heated conduit 28. Hot fluid, e.g. water, is circulated in the closed circuit 31 through a hot fluid pump 32. The wall of the heated conduit 28 is heated by the pipe 31 and heats by conduction the slurry mixture “M” inside the heated conduit 28. The heating device 12 is configured or programmed to rise the temperature of the slurry mixture “M” to a highPMP1P42WO FTR4092 PCT

[0185] temperature “Th” greater than 60°C. For instance, the hot fluid has a temperature from 70°C to 75°C.

[0186] The heating device 12 comprises a slurry storage tank 33 placed downstream of the heated conduit 28. An inlet 33A of the slurry storage tank 33 is connected to the heated conduit 28, for instance through a piping, to receive the slurry mixture “M” heated in the heated conduit 28. An auxiliary heater 34 is operatively active in said slurry storage tank 33 to keep the slurry mixture “M” in the slurry storage tank 33 at said high temperature for a time period “Ath”. In the example embodiment of Figure 3, an inner chamber 35 of the slurry storage tank 33 is partially filled with the slurry mixture “M” and an upper part of the inner chamber 34 is empty. The auxiliary heater 34 comprises a source of steam 36 which is connected to the upper empty part of the inner chamber 35 to inject steam in said upper empty part of the slurry storage tank 33.

[0187] A temperature controller 37 is configured to control the heater 29 and the auxiliary heater 34 to bring the slurry mixture “M” up to the high temperature “Th” and to keep the slurry mixture “M” to said high temperature “Th” in the slurry storage tank 33 for said time period “Ath”. The temperature controller 37 comprises a temperature sensor 38 positioned and configured to sense a temperature of the slurry mixture in the slurry storage tank 33 and a temperature sensor, not shown in Figures, positioned and configured to sense a temperature of the slurry mixture flowing across the heated conduit 28. The temperature controller 37 is for instance also operatively connected to the steam chamber 30, to the hot fluid pump 32 and to the source of steam 36 and / or to valves on the piping and comprises a feedback mechanism configured or programmed to command the heater 29 and the auxiliary heater 34 in order to adjust the temperature of the slurry mixture “M” in the heated conduit 28 and in the slurry storage tank 33.

[0188] In the disclosed embodiment, the temperature controller 37 is configured or programmed to rise the temperature of the slurry mixture “M” in the heated conduit 28 to the high temperature “Th” from 70°C to 75°C, preferably of 72°C, and to keep the slurry mixture “M” to said high temperature “Th” in the slurry storage tank 33 for the time period “Ath” ranging from 15 seconds to 30 seconds.

[0189] By controlling, for instance during the startup of the apparatus 1, the slurry pump 25 and the further slurry pump 26, a certain amount of the slurry mixture “M” is held in the slurry storage tank 33 while the slurry mixture “M” continuously flows in and out of the slurry storage tank 33. The slurry storage tank 33 works as a buffer to achieve the desired time period “Ath”. According to the method for producing the cast sheet “S” here disclosed, the slurry mixture “M” is thus subjected to HTST pasteurization.PMP1P42WO FTR4092 PCT

[0190] The cooling device 13 receives the pasteurized slurry mixture “M” from an outlet 33B of the slurry storage tank 33 and lowers the temperature of the slurry mixture “M” to a low temperature “Tl”. The cooling device 13 comprises a cooled conduit 39 connected, through a piping, to the outlet 33B of the slurry storage tank 33 and a cooler 40 operatively active on said cooled conduit 39 to cool the slurry mixture “M” flowing in the cooled conduit 39. The cooling device 39 shown in Figure 3 comprises two sources of a cold fluid 41, such as two cold water tanks with chillers, each connected to a pipe 42 forming a closed circuit. A portion of each pipe 42 is coiled around the cooled conduit 39 and is coupled to a wall of the cooled conduit 39 to cool the cooled conduit 39 and the slurry mixture “M” by conduction. A temperature of the cold fluid is lower than 15°C, for instance lower than 10°C, optionally from 4°C to 15°C, optionally from 4°C to 10°C, optionally from 4.4°C to 7.2°C. Heat from the slurry mixture “M” is transferred to the cold water. The cold water is circulated in the pipe 42 through pumps, not shown.

[0191] The temperature controller 37 is operatively connected to the two sources of a cold fluid 41 (Figure 3) and is also configured to control the cooler 40 to bring the slurry mixture “M” down to the low temperature “Tl” lower than 15°C, preferably lower than 10°C, optionally from 4°C to 15°C, optionally from 4°C to 10°C, for instance ranging from 4.4°C to 7.2°C, in a cooling time “Ate” from 5 seconds to 10 seconds.

[0192] Once cooled, the slurry mixture “M” is temporarily stored in the silo 14, for instance for 10 to 90 minutes, and then pumped to the casting box 15 through the slurry pump 25.

[0193] In other embodiments, a length of the heated conduit 28 (see Figure 1) is such to heat the slurry mixture “M” and to keep said high temperature of the slurry mixture “M” for the time period “Ath” while the slurry mixture “M” flows in the heated conduit 28. The slurry storage tank 33 may be not present.

[0194] In other embodiments which are not part of the present invention, the slurry mixture “M” is heated and kept at the high temperature for the time period “Ath” only in the slurry storage tank 33 instead of in the heated conduit.

[0195] For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term "about". Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ± 5 percent of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated abovePMP1P42WO FTR4092 PCT

[0196] provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

Claims

PMP1P42WO FTR4092 PCTCLAIMS1. A method of producing a cast sheet for smoking articles or aerosol generating articles, the method comprising:mixing ingredients of a recipe and water to form a slurry mixture (M);feeding the slurry mixture (M) to a casting box (15);casting the slurry mixture (M) on a surface to form a cast sheet (S);wherein the method further comprises: heating the slurry mixture (M) to a high temperature (Th) greater than 60°C and keeping the high temperature (Th) of the slurry mixture (M) for a time period (Ath) such to eliminate at least part of organisms in said slurry mixture (M); wherein heating is performed while the slurry mixture (M) flows in a heated conduit (28) towards the casting box (15).

2. Method according to claim 1 , wherein the high temperature (Th) and the time period (Ath) are such to achieve a pasteurization of the slurry mixture (M).

3. Method according to claim 1 or 2, wherein the high temperature (Th) is from 70°C to 75°C and the time period (Ath) is from 15 seconds to 30 seconds.

4. Method according to any of claims 1 to 3, wherein heating the slurry mixture (M) comprises: heating the heated conduit (28) so that the slurry mixture (M) is heated by conduction through said heated conduit (28).

5. Method according to any of claims 1 to 4, wherein keeping the high temperature (Th) of the slurry mixture (M) for the time period (Ath) is carried out while the slurry mixture (M) flows in the heated conduit (28); or wherein the method further comprises: after heating the slurry mixture (M) in the heated conduit (28), holding the slurry mixture (M) in a slurry storage tank (33) before feeding to the casting box (15), wherein the time period (Ath) is a time the slurry mixture (M) dwells in the slurry storage tank (33).

6. Method according to any of claims 1 to 5, wherein, once the time period (Ath) is elapsed and before feeding to the casting box (15), the slurry mixture (M) is cooled to a low temperature (Tl) lower than 15°C.

7. An apparatus for producing a cast sheet for smoking articles or aerosol generating articles, the apparatus comprising:PMP1P42WO FTR4092 PCTat least one of a mixer (2) configured for mixing ingredients of a recipe and water to form a slurry mixture (M) and a slurry container (27) configured to hold the slurry mixture (M);a casting box (15) in fluid communication with the mixer (2) or with the slurry container (27) to receive the slurry mixture (M);a surface located under the casting box (15) and configured to receive the slurry mixture (M) from said casting box (15) and to form a cast sheet (S) on said surface;wherein the apparatus (1) further comprises a heating device (12) operatively located between the mixer (2) or the slurry container (27) and the casting box (15) and configured to eliminate at least part of organisms in the slurry mixture (M);wherein the heating device (12) comprises:a heated conduit (28) in fluid communication with the mixer (2) or the slurry container (27) and the casting box (15), the slurry mixture (M) flowing across said heated conduit (28) from the mixer (2) or the slurry container (27) towards the casting box (15);a heater (29) operatively active on said heated conduit (28) to heat the slurry mixture (M) flowing towards the casting box (15) to a high temperature (Th) greater than 60°C.

8. Apparatus according to claim 7, wherein the heater (29) is external to said heated conduit (28) to heat a wall of the heated conduit (28) and to heat the slurry mixture (M) by conduction.

9. Apparatus according to claim 8, wherein the heater (29) comprises a source of a hot fluid (30) and a pipe (31) connected to the source of hot fluid (30) and coupled to the wall of the heated conduit (28).

10. Apparatus according to any of claims 7 to 9, wherein a length of the heated conduit (28) is such to keep the slurry mixture (M) at said high temperature (Th) for a time period (Ath); or wherein the heating device (12) further comprises a slurry storage tank (33) placed downstream of the heated conduit (28) and connected to said heated conduit (28); an auxiliary heater (34) operatively active in said slurry storage tank (33) to keep the slurry mixture (M) in the storage tank (33) at said high temperature (Th) for a time period (Ath).PMP1P42WO FTR4092 PCT11. Apparatus according to claim 10, wherein the auxiliary heater (34) comprises a source of steam (36) connected to an inner chamber (35) of the slurry storage tank (33), said inner chamber (35) holding the slurry mixture (M).

12. Apparatus according to any of claims 7 to 11, further comprising a cooling device (13) operatively located downstream of the heating device (12) and upstream of the casting box (15); the cooling device (13) being configured to lower the temperature of the slurry mixture (M) coming from the heating device (12) to a low temperature (Tl).

13. Apparatus according to claim 12, wherein the cooling device (13) comprises: a cooled conduit (39) in fluid communication with the heating device (12), the slurry mixture (M) flowing across said cooled conduit (39) from the heating device (12) towards the casting box (15);a cooler (40) operatively active on said cooled conduit (39) to cool the slurry mixture (M) flowing towards the casting box (15).

14. Apparatus according to claim 13, wherein the cooler (40) is external to said cooled conduit (39) to cool a wall of the cooled conduit (39) and to cool the slurry mixture (M) by conduction.

15. Apparatus according to claim 14, wherein the cooler (40) comprises a source of a cold fluid (41) and a pipe (42) connected to the source of cold fluid (41) and coupled to the wall of the cooled conduit (39).

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