RU2786040C2 - Casting machine and method for producing a cast sheet of material containing alkaloids - Google Patents

Abstract

FIELD: casting machines.

SUBSTANCE: invention relates to a casting machine and a method for producing a cast web of material containing alkaloids, in particular the material is a homogenized tobacco material, preferably used in an aerosol generating product, such as, for example, a cigarette or a "heating without combustion" type tobacco-containing product. A casting machine for producing a cast sheet of an alkaloid-containing material, comprising a casting box configured to receive a slurry of alkaloid-containing material; a pulp supply element configured to supply pulp to the casting box; moving base; a casting blade configured to cast the slurry contained in the casting box onto the movable base, thereby producing a cast web; redirecting ribs configured to come into contact with the pulp and placed inside the casting box. The method for producing a cast sheet of material containing alkaloids, contains the introduction of the pulp into the casting box; providing redirecting ribs within the mold box to bend the slurry flow path within the mold box; pouring the pulp onto a movable base by means of a casting blade.

EFFECT: elimination of heterogeneity and defects in the cast web of homogenized tobacco.

15 cl, 9 dwg

Description

The present invention relates to a casting machine and a method for producing a cast web of material containing alkaloids.

In particular, the alkaloid-containing material is a homogenized tobacco material, preferably used in an aerosol-generating article such as, for example, a cigarette or a heat-not-burn tobacco-containing product.

Currently, in the production of tobacco products, in addition to tobacco leaves, homogenized tobacco material is also used. Such homogenized tobacco material is usually made from parts of the tobacco plant that are less suitable for the production of cut tobacco filler, such as, for example, tobacco stems or tobacco dust. Typically, tobacco dust is formed as a by-product during the processing of tobacco leaves during the manufacturing process.

The most widely used forms of homogenized tobacco material are reconstituted tobacco sheet and shaped sheet (TCL is short for shaped tobacco sheet). The process for making sheets of homogenized tobacco material typically includes the step of mixing tobacco dust and a binder to form tobacco pulp. The pulp is then used to create a tobacco web, for example by casting the viscous pulp onto a moving metal band to form a so-called molded sheet. Alternatively, low-viscosity, high-water pulp can be used to make reconstituted tobacco in a process similar to papermaking. Once produced, the homogenized tobacco webs can be cut in a manner similar to whole leaf tobacco to produce cut tobacco filler suitable for cigarettes and other smoking products. A method for the manufacture of such homogenized tobacco is disclosed, for example, in European patent EP 0565360.

In an aerosol-generating article of the "heat without combustion" type, the aerosol-generating substrate is heated to a relatively low temperature to produce an aerosol but prevent combustion of the tobacco material. In addition, the tobacco present in the homogenized tobacco material is usually exclusively tobacco or contains mainly tobacco present in the homogenized tobacco material of such a "heating without combustion" type aerosol generating article. This means that the composition of the aerosol that is generated by such an aerosol-generating product of the "heat without combustion" type is essentially based only on homogenized tobacco material. Therefore, it is important to ensure proper control of the composition of the homogenized tobacco material in order to control, for example, the taste of the aerosol.

Due to variations in the physical properties of the pulp, such as consistency, viscosity, fiber size, particle size, moisture content, or pulp soak time, unplanned variations in the application of the pulp to the substrate during casting of the homogenized tobacco web may occur when using standard casting methods and casting machines. . Suboptimal molding methods and equipment can cause inhomogeneity and defects in the cast web of homogenized tobacco.

The heterogeneity of the homogenized tobacco web can lead to difficulties in post-processing the homogenized tobacco web to produce an aerosol generating article. For example, inhomogeneity can lead to web cracking or even web tearing during fabrication or further processing of the web. This, in turn, can lead, for example, to equipment shutdowns. Additionally, a heterogeneous tobacco web can lead to unplanned differences in aerosol delivery between aerosol generating articles made from the same homogenized tobacco web.

There is a need for a casting machine and method for producing a cast web of material containing alkaloids that is adapted to overcome or at least reduce the above problem.

The present invention relates to a casting machine for producing a cast sheet of an alkaloid-containing material, which comprises: a casting box capable of receiving a slurry of alkaloid-containing material; a pulp supply element configured to supply pulp to the casting box; moving base; a casting blade configured to cast the slurry contained in the casting box onto the movable base, thereby obtaining a cast web; redirecting ribs configured to come into contact with the pulp and placed inside the casting box.

The proposed casting machine is aimed at ensuring a uniform distribution of the pulp on a mobile basis. The presence of ribs in the slurry flow path enhances slurry agitation prior to casting, which can be expected to improve the thickness control of the cast sheet. In the flow to the casting blade, the pulp has to flow around the ribs, spreading and creating non-linear trajectories. This essentially prevents linear pulp flow.

As used herein, the term "sheet" means a flat element having a width and length substantially greater than its thickness. The width of the sheet is preferably greater than about 10 millimeters, more preferably greater than about 20 millimeters or approximately 30 millimeters. Even more preferably, the width of the sheet is from about 100 millimeters to about 300 millimeters. A continuous "sheet" is referred to in this document as a "canvas".

In this document, the term "casting vane" means an element of an oblong shape, which may have a substantially constant cross-section along the main parts of its longitudinal extent. It contains at least one edge, which is designed to come into contact with a pasty, viscous or liquid-like substance, which will be affected by the specified edge, such as pulp. Said edge may have a sharp and knife-like shape. Alternatively, it may be rectangular or rounded.

As used herein, the term "movable base" means any means containing a surface that can move in at least one direction. The movable base may form a closed loop to allow continuous movement in one direction. However, the movable base can also move in a reciprocating mode. The movable base may include a conveyor belt. The movable base may be substantially flat and may have a structured or unstructured surface. The mobile base may not contain holes in its surface, or may contain only holes of such a size that they are impermeable to the pulp located on it. The movable base may comprise a sheet-like movable and flexible band. The tape may be made of a metallic material including, but not limited to, steel, copper, iron and copper alloys, or rubber material. The tape can be made of a heat-resistant material, which allows it to be heated to speed up the drying process of the pulp.

As used herein, the term "pulp" means a liquid-like, viscous or pasty material which may contain an emulsion of another similar liquid, viscous or pasty material, and which may contain some solid particles, provided that the state of the pulp remains liquid-like, viscous or pasty.

"A material containing alkaloids" is a material that contains one or more alkaloids. Alkaloids may include nicotine. Nicotine can be found, for example, in tobacco.

Alkaloids are a group of chemical compounds of natural origin, which usually contain atoms of nitrogenous bases. This group also includes some related compounds with neutral and even slightly acidic properties. Some synthetic compounds or similar structures are also referred to as alkaloids. In addition to carbon, hydrogen, and nitrogen, alkaloids can also contain oxygen, sulfur, and, less commonly, other elements such as chlorine, bromine, and phosphorus.

Alkaloids are produced by many organisms, including bacteria, fungi, plants, and animals. They can be obtained by purification from crude extracts of these organisms by acid-base extraction. Examples of alkaloids are caffeine, nicotine, theobromine, atropine, tubocurarine.

In this document, the term "homogenized tobacco material" means a material obtained by agglomeration of tobacco particles, which contains the alkaloid nicotine. Thus, the material containing alkaloids may be a homogenized tobacco material.

The most widely used forms of homogenized tobacco material are reconstituted tobacco sheet and molded sheet. The process for making sheets of homogenized tobacco material typically includes the step of mixing tobacco dust and a binder to form a slurry. This suspension is then used to produce a tobacco web. For example, by casting a viscous pulp onto a moving metal strip, a so-called shaped sheet is obtained. Alternatively, low-viscosity, high-water pulp can be used to make reconstituted tobacco in a process similar to papermaking.

Tobacco sheeting may be referred to as reconstituted sheeting and is prepared using particulate tobacco (eg, reconstituted tobacco) or a particulate tobacco blend, a humectant, and an aqueous solvent to form a tobacco composition. This tobacco composition may then be molded, extruded, rolled, or pressed to form a sheet material from the tobacco composition. Tobacco sheet can be made using a wet process in which tobacco fine particles are used to form a paper-like material; or a sheet casting process in which tobacco fine particles are mixed with a binder and cast onto a moving belt to form a sheet.

The homogenized tobacco leaf typically contains, in addition to tobacco, a binder and an aerosolizing agent such as guar and glycerin.

As used herein, the term "aerosol-forming material" means a material that, when heated, is capable of releasing volatile compounds to generate an aerosol. Tobacco together with other compounds, in particular homogenized tobacco leaf containing an aerosolizing agent, can be classified as an aerosolizing material. The aerosol-forming substrate may comprise or consist of an aerosol-forming material. The homogenized tobacco leaf can be used as an aerosol forming material.

The pulp may contain several different components or ingredients. These components can affect the properties of the cast web of material containing alkaloids. The first ingredient is a material containing alkaloids, for example in the form of a powder. This material may be, for example, a tobacco powder mixture, which preferably contains the bulk of the tobacco present in the pulp. The tobacco powder mixture is the source of the majority of the tobacco in the homogenized tobacco material and thus imparts flavor to the final product, such as the aerosol resulting from heating the homogenized tobacco material. Cellulosic pulp containing cellulose fibers acting as a strengthening agent is preferably added to the pulp in order to increase the tensile strength of the web of alkaloid-containing material. Preferably a binder is added. Preferably, an aerosolizing agent may be added. Preferably, a binder and an aerosolizing agent are added to improve the tensile strength properties of the homogenized sheet and promote aerosol formation. In addition, water can be added to the pulp to achieve a certain viscosity and moisture that is optimal for casting a web of material containing alkaloids.

The amount of binder added to the pulp may range from about 1 percent to about 5 percent of the dry weight of said pulp. More preferably, it ranges from about 2 percent to about 4 percent. The binder used in the pulp can be any of the gums or pectins described herein. The binder can ensure that the tobacco powder remains substantially dispersed throughout the homogenized tobacco web. Although any binder may be used, preferred binders are natural pectins such as fruit, citrus or tobacco pectins; guar gums such as hydroxyethyl guar and hydroxypropyl guar; locust bean gums such as hydroxyethyl and hydroxypropyl locust bean gums; alginate; starches such as modified or derivatized starches; celluloses such as methyl, ethyl, ethylhydroxymethyl and carboxymethylcellulose; tamarind gum; dextran; pullalone; konjac flour; xanthan gum; and the like. A particularly preferred binder for use in the present invention is guar.

In general, the incorporation of cellulose fibers, acting as a reinforcing agent, into the pulp increases the tensile strength of the web of tobacco material. Accordingly, the addition of cellulose fibers can increase the resilience of the web of homogenized tobacco material. Cellulose fibers for inclusion in the pulp for homogenized tobacco material are known in the art and include, without limitation, softwood fibers; hardwood fibers; jute fibers; linen fibers; tobacco fibers and combinations thereof. In addition to pulping, cellulosic fibers may be subjected to suitable processes such as cleaning, mechanical pulping, chemical pulping, bleaching, sulfate pulping, and combinations of the above. Cellulosic fibers may contain materials from tobacco stems, veins, or other materials from the tobacco plant. Preferably, cellulosic fibers, such as wood fibers, have a low lignin content. As an alternative to or in addition to the above fibers, vegetable fibers, including hemp and bamboo, can be used. The length of the cellulose fibers is preferably from about 0.2 millimeters to about 4 millimeters. Preferably, the average length per weight of the cellulose fibers is from about 1 millimeter to about 3 millimeters. In addition, preferably the amount of cellulose fibers is from about 1 percent to about 7 percent, based on dry weight, based on the total weight of the pulp (or homogenized tobacco leaf).

Suitable aerosol forming agents for incorporation into the pulp for homogenized tobacco material are known in the art and include, without limitation, monohydric alcohols such as menthol, polyhydric alcohols such as triethylene glycol, 1,3-butanediol, and glycerin; esters of polyhydric alcohols such as glycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- or polycarboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate.

Examples of preferred aerosol forming agents are glycerin and propylene glycol.

The aerosolizing agent content of the pulp may be greater than about 5 percent on a dry weight basis. The aerosolizing agent content of the pulp may be from about 5 percent to about 30 percent on a dry weight basis. More preferably, the aerosolizing agent is present in an amount of from about 10 percent to about 25 percent, based on the dry weight of the pulp. More preferably, the aerosolizing agent is present in an amount of from about 15 percent to about 25 percent, based on the dry weight of the pulp.

The binder and cellulose fibers are preferably included in a weight ratio of from about 1:7 to about 5:1. More preferably, the binder and cellulose fibers are included in a weight ratio of from about 1:1 to about 3:1.

The binder and aerosolizer are preferably included in a weight ratio of from about 1:30 to about 1:1. More preferably, the binder and aerosolizer are included in a weight ratio of from about 1:20 to about 1:4.

Preferably, the alkaloid-containing material is tobacco. The binder and tobacco particles are preferably included in a weight ratio of from about 1:100 to about 1:10. More preferably, the binder and tobacco particles are included in a weight ratio of from about 1:50 to about 1:15, even more preferably from about 1:30 to 1:20.

The aerosolizing agent and tobacco particles are preferably included in a weight ratio of from about 1:20 to about 1:1. More preferably, the aerosolizer and tobacco particles are included in a weight ratio of from about 1:6 to about 1:2.

The aerosolizing agent and cellulose fibers are preferably included in a weight ratio of from about 1:1 to about 30:1. More preferably, the aerosolizer and cellulose fibers are included in a weight ratio of from about 5:1 to about 15:1.

The cellulose fibers and tobacco particles are preferably included in a weight ratio of from about 1:100 to about 1:10. More preferably, the cellulose fibers and tobacco particles are preferably included in a weight ratio of from about 1:50 to about 1:20.

The machine according to the present invention comprises a casting box adapted to receive the slurry and a movable base, the casting of the pulp being carried out by means of a casting blade. The movable base determines the casting direction during movement.

The pulp may reach the casting box from another location. Therefore, the casting box may not be the place where the slurry is formed. For example, the slurry may be formed in a hopper, from where it is transported to a casting box through a suitable tube. Preferably the slurry is continuously fed into the casting box at the same time as the slurry is cast onto the movable base to form a continuous web of material containing alkaloids. The hopper and the casting box are thus preferably in fluid communication, which allows the slurry to flow from one to the other.

The casting box is preferably box-shaped. Preferably, the mold box includes walls. More preferably, the walls in turn include side walls. The side walls may comprise first and second pairs of opposing walls, referred to as first, second side walls in the first pair, and third and fourth side walls in the second pair. The side walls are preferably substantially vertical or inclined with respect to a vertical plane. The first and second side walls and the third and fourth side walls, respectively, face each other. Preferably, the walls of the casting box include a bottom wall. The bottom wall may contain an opening. Preferably, the entire lower part of the casting box forms an opening. Alternatively, the bottom wall may be completely closed.

The walls of the mold box form the inner volume of the mold box, i.e., the walls define the inner volume of the mold box. As mentioned above, the casting box contains an opening in the lower region, for example, on the bottom wall, so that the box is not a completely closed container. The hole is provided for pulp casting. Thus, the internal volume of the casting box is in contact with the external environment. Due to the presence of said hole, the volume of the "theoretical" box is considered as the internal volume of the casting box, in which the area bounded by the hole is closed. Accordingly, in the preferred embodiment, the line of demarcation between the internal volume of the box and the external environment is drawn as if this opening were closed by a wall. The opening may be formed in more than one wall (eg, corner openings, which are openings formed at the corners of the box). In addition, more than one hole may be present.

The mold box may include a top wall or lid, or it may be open. In the case of a lid, it may be fixed or movable. In the latter case, it may be slidable along the side walls of the casting box.

The casting blade is preferably positioned perpendicular to the casting direction. The web of material is formed by means of a casting vane, which pours the slurry in the casting box into a moving base. The slurry, for example, falls by gravity from the casting box and, through a hole in the bottom wall, comes into contact with the casting blade. The edge of the casting blade forms a gap with the surface of the movable base, and the pulp passes through the hole formed by the said gap. The thickness of the cast web of material may be determined by the distance, among other things, between the edge of the casting blade that comes into contact with the pulp and the surface of the movable base, ie the width of said gap.

Preferably, the movable base is located at least partially in part below the opening in the bottom of the casting box.

The casting box contains a plurality of ribs. Said ribs change the flow path of the pulp flowing from the casting box to the casting blade. Thus, these ribs change the flow of the pulp: an essentially "linear" flow, i.e. a flow flowing in one essentially rectilinear direction, generally determined by gravity, turns into a more complex path, since the pulp has to change the trajectory of movement on various surfaces formed by the specified edges.

Without being limited by theory, the pulp is likely to exhibit shear thinning, i.e., there is an inverse relationship between natural viscosity and shear stress. Thus, good mixing of the slurry inside the casting can be useful in the manufacturing process, in particular for controlling the thickness of the cast sheet. For this reason, ribs are preferably built into the casting box, which influence the flow of the pulp. The ribs, which may be shaped like blades, advantageously function as a mass spreader as well as static mixers, since the slurry must flow around these ribs during its flow, spreading and creating non-linear flows. Accordingly, the pulp has "complex local motion" around the ribs and, at the same time, a general motion created by the movement of the conveyor belt and under the action of gravity, in the direction of the casting blade.

Thus, preferably, the linear flow of the pulp is prevented as far as possible also in the area where the pulp passes through the thin gap between the casting blade and the movable base. Based on manufacturing experience, the longitudinal (relative to the direction of casting) linear flows of slurry entering the mold box and/or within the mold box can be related to the linear transverse heterogeneity of the cast sheet, in particular with respect to its thickness, physical characteristics and visual appearance.

The effect that the ribs have on the pulp flow can be determined and selected by the particular geometry, size, number and relative proximity between the ribs. These parameters can be developed by computer simulation, taking into account the configuration of the casting box and the characteristics of the slurry.

Each edge defines a three-dimensional volume. In one dimension, the edges are much smaller than in the other two. This smaller dimension represents their thickness. The ribs are preferably blade-shaped elements that are located in the casting box where they can impede the flow of the slurry. Each rib defines two substantially opposite main surfaces and two thin side surfaces connecting the two main surfaces.

The ribs may protrude from one of the side walls of the casting box, for example they can be fixed to such a side wall and protrude from the inner surface of the side wall in contact with the slurry. Preferably, the major surfaces of each rib are substantially perpendicular to the side wall of the mold box.

Alternatively or additionally, the ribs may face the movable base. The ribs can be made in such a way that their side surface faces the movable base or the lower opening of the casting box. To this end, the ribs may be connected to one another with other suitable rods or a frame attached to the side walls of the mold box, or the ribs may be attached to the lid of the mold box, also in a position facing the hole located at the bottom of the mold box.

In the case of a plurality of ribs, all ribs can be connected by a connecting element such as a rod or a frame. A bar or frame can also connect edges into separate groups. Each group can have one connector that is different from other groups. The connection by means of a connecting element allows all ribs to be removed for the purpose of cleaning or repair. In addition, it allows you to adjust the position of all edges at the same time.

The ribs can be attached directly to the walls of the casting box. The ribs may be connected by a frame or rod and the frame or rod may be attached to the side walls, preferably opposite side walls, and the ribs themselves may not be in contact with the walls of the mold box.

Edges can define an axis. In plan view, the ribs may form a substantially curved shape. This curve has first and second ends. The direction given by the edges is determined by the line connecting the first and second ends. The top view of the ribs is a view taken parallel to the side surface of the ribs.

The ribs are preferably curved, i.e. they form a concave part or a convex part. The ribs may have more than one concave surface. In a plan view, the fins may form a C-shape, an S-shape, or similar shapes. They can also be flat. Preferably, the main surface of the ribs is concave or convex.

The possible cross-sectional shapes of the ribs are those that are preferred to create the desired "deviation" or change in pulp orientation at any given position in the mold box.

In terms of materials, the fins are preferably made of metal, more preferably hard metal alloys such as stainless steel hard alloys. Alternatively or additionally, the ribs may comprise reinforced surfaces or other materials that are highly resistant to pulp abrasion due to the high content of silica in tobacco particles and its abrasive effect on all types of materials, including metals. A "hard" material or coating is used on said ribs because of the wear caused by the pulp and the nicotine content of the pulp, which also generally has an aggressive effect on the materials.

The presence of ribs in the flow path can reduce differences in fluidity and associated physical characteristics of the slurry that may otherwise be present. The "longitudinal shading stripes" that may appear in a cast sheet without ribs may be absent if the ribs are in a mold box.

Preferably, the redirecting ribs include a plurality of curved ribs. Preferably, the ribs are not flat, but curved. Accordingly, the main surfaces of the ribs thus comprise a curved surface. The curvature can be used to change the direction of pulp flow in several different directions, depending on the orientation of the rib that the pulp is hitting.

Preferably, the plurality of curved ribs form at least one row of curved ribs. Preferably, many ribs are present. More preferably, the ribs are located across the entire width of the casting box, which is essentially equal to the width of the casting blade, whereby the ribs act on all the pulp that moves towards the casting blade. Preferably, said ribs are arranged side by side with a gap between them through which pulp can flow. Thus, the slurry preferably flows through different channels, with each channel formed by two surfaces, one of which belongs to one rib and another one that belongs to an adjacent rib.

Preferably, the ribs form groups in which all ribs "point" in the same direction. For example, the redirecting ribs may be divided into rows, and each row includes ribs having axes parallel to each other. The rows of ribs are arranged one below the other along the pulp flow direction, for example, if a first and a second row of ribs are present, the first row of ribs is located above the second row in the pulp flow direction.

Preferably, each curved rib of the plurality of ribs forms a concave surface, with the curved ribs of the same row having equally oriented concave surfaces. "Equally oriented concave" means that the concave surfaces of all the ribs in the row are on the same side of their axis. Edges can have more than one curvature. All rib bends of the row of ribs, which are preferably located across the entire width of the casting box, preferably "point" in the same direction. The casting blade is preferably positioned perpendicular to the casting direction.

Preferably, the concave surfaces of adjacent rows are in opposite orientation. The motion imparted to the flow by the fins is "as complex as possible", so that it deviates from linearity and provides better mixing.

Preferably, the casting machine includes a first adjusting element rotatable about an axis of the redirecting ribs. As mentioned above, in the top view, the edges form an axis. The orientation of this axis can be changed. Preferably, if there are a plurality of ribs, the first adjusting element can change the orientation of the axes of all ribs at the same time. Preferably, the orientation of the axes of the edges is the same for all edges of the set. Preferably, the first adjusting element is located above the fins in the vertical direction. For example, if the casting machine includes a lid, said ribs are connected to the pulp-facing surface of the lid, while the first adjusting element is located on the opposite surface of the lid. In addition, the first adjusting element may be located above each individual rib. The first adjusting element may be a knob that rotates a shaft inserted into the rib perpendicular to the major surfaces of the ribs.

Preferably, the casting box includes a side wall, and the casting machine includes a second adjusting element configured to change the distance between the redirecting ribs and the movable base, or between the redirecting ribs and the side wall of the casting box. Since the axis of the ribs can change, in the preferred embodiment, their height relative to the vertical axis can also change. Thus, a second adjusting element is provided which can change the position of the ribs, for example by moving them along a predetermined axis, such as the vertical axis. Preferably, in the case of connected ribs, the second adjusting element changes the position of all ribs simultaneously.

This can be accomplished by mechanically synchronizing/indexing the movement of each axis controlling the angle/orientation of each rib by means of an element that mechanically interacts with all axes, such as a bar with gears interacting with the gears present on each axis of each rib. In this case, the movement of the rod leads to the rotation of all axes of the ribs in the same way and simultaneously.

Preferably, said casting box includes a side wall, and said redirecting ribs face the side wall of the casting box. Preferably, the redirecting ribs are fixed to the side wall of the casting box.

In a preferred embodiment, said casting box contains an opening, while the movable base is located under the opening, and said redirecting ribs face the movable base. The redirecting ribs preferably divert the flow just prior to casting. Thus, in the preferred embodiment, the redirecting ribs are located above or at the level of the hole formed in the casting box, from which the pulp falls onto the movable base, when casting with a casting vane. The redirecting ribs may be attached to the lid of the mold box or to the frame, which in turn is attached to the side walls of the mold box.

The present invention also relates to a method for producing a cast sheet of material containing alkaloids, including providing a casting box; providing a casting blade connected to the casting box; providing a movable base facing the casting blade; introduction of the pulp into the casting box; providing redirecting ribs within the mold box to change the path of pulp flow in the mold box; and casting the pulp onto the movable base by means of a casting blade.

The advantages of the method have already been outlined in the description of the machine and will not be repeated.

Preferably, the provision of redirection ribs includes the provision of redirection ribs facing the movable base. The redirecting ribs can be located in any position within the casting box. Preferably they are located in a volume through which the slurry flows prior to casting, such as, for example, the volume above the opening in the casting box above the movable base.

In a preferred embodiment, the method includes adjusting the orientation of the redirecting ribs depending on the parameters of the pulp or cast sheet.

In a preferred embodiment, the method includes adjusting the distance between the redirecting ribs and the movable base, or between the redirecting ribs and the side wall of the casting box, depending on the parameters of the pulp or cast sheet. More preferably, the method includes the step of rotating the redirecting ribs about an axis perpendicular to the movable base.

The position and orientation of the redirecting ribs can be adjusted depending on the characteristics of the pulp and the desired characteristics of the cast sheet. The redirecting ribs can be configured to reorient and move away from and towards the side wall, the lid of the mold box, or the movable base, depending on the position where they are located within the mold box.

Preferably, the cast sheet of material containing alkaloids contains a homogenized tobacco sheet.

The present invention may also relate to a casting machine for producing a cast sheet of material, comprising: a casting box configured to receive a slurry of material containing alkaloids; a pulp supply element configured to supply pulp to the casting box; moving base; a casting blade configured to cast the pulp contained in the casting box onto the movable base, thereby obtaining a cast sheet; and redirecting ribs configured to come into contact with the pulp and placed in the casting box.

The present invention may also relate to a method for producing a cast sheet, including providing a mold box; providing a casting blade connected to the casting box; providing a movable base facing the casting blade; introduction of the pulp into the casting box; providing redirecting ribs within the mold box to change the path of pulp flow in the mold box; and casting the pulp onto the movable base by means of a casting blade.

Other advantages of the present invention will become apparent from its detailed description with non-limiting reference to the accompanying drawings, in which:

Fig. 1 is a schematic side sectional view of a part of a machine for producing a web of material containing alkaloids;

Fig. 2 is a perspective view of a portion of the machine shown in FIG. one;

Fig. 3 is a schematic side view of the machine shown in FIG. 1, in a different configuration;

Fig. 4 is a perspective view of a portion of the machine shown in Figures 1-3;

Fig. 5 is a schematic side sectional view of a second embodiment of a machine for producing a web of material containing alkaloids;

Fig. 6 is a schematic front view of the machine shown in FIG. five;

Fig. 7 is a schematic perspective view of FIG. five.;

Fig. 8 is a schematic side view of a third embodiment of a machine for producing a web of material containing alkaloids; and

Fig. 9 is a schematic side sectional view of a third embodiment of a machine for producing a web of material containing alkaloids.

With reference to Figures 1-4, a first embodiment of a casting machine for producing a cast web of an alkaloid-containing material according to the present invention, designated 100, is shown. Figures 1 and 2 show only a part of the casting machine 100.

In particular, the casting machine 100 is configured to produce a cast web from a homogenized tobacco material (not shown in the drawings).

The casting machine 100 includes a casting box 10 containing pulp 18, a movable base 2 and a casting blade 1, wherein the casting blade 1 pours the pulp 18 contained in the casting box 10 onto the moving base 2, thereby obtaining a cast sheet of homogenized tobacco material. .

Slurry 18 from buffer tanks (not shown in the drawings) is transferred to the casting box 10, usually by means of a pump (not shown in the drawings). Preferably, the pump includes a flow control (not shown in the drawings) to control the amount of slurry 18 supplied to the mold box 10. The pump is advantageously adapted to keep the slurry travel time at the minimum required level. The pump is fluidly connected, for example, by means of a slurry distributor 5, to the casting box 10, so as to feed the slurry 2 into it.

The casting box 10 includes side walls containing first and second opposite walls 3, 4. The casting blade 1 is connected to the casting box 10 on the second wall 4. The casting box 10 is usually formed by four side walls, i.e. the first and second opposite walls 3, 4 and third and fourth opposite walls (not shown in the figures) that connect the first and second opposite walls 3, 4.

The movable base 2 comprises, for example, a continuous stainless steel belt with a drum assembly. The specified drum assembly contains the main drum 21, located below the casting box 10 and moving the movable base 2. Preferably, the casting box 10 is mounted on top of the main drum 21.

The pulp is poured onto the steel belt - at the level of the drum 21 - by means of a casting blade 1 which creates a continuous sheet of homogenized tobacco material. In order to ensure that the slurry reaches the casting blade and thus the movable base, the casting box 10 has an opening 17 in its bottom region, and this opening 17 extends across the width of the casting casing 10. The opening 17 is located above and near the drum 21.

The top of the mold box 10 is open in this embodiment.

The movement of the steel band 2 advances the pulp 18 towards the casting blade 1, for example, towards the second wall 4. The casting blade 1 pours part of the pulp 18 onto the steel band 2, while the remaining majority of the pulp 18 turns back and recirculates inside the casting box 10. The steel strip 2 moves in the casting direction (see arrow 24 in the figures).

The casting blade 1 is connected to the casting box 10 for casting pulp. The casting blade 1 has a dominant dimension which is its axial width. By way of example, the casting blade 1 is substantially rectangular.

The casting blade 1 is attached to the casting box 10, preferably by means of an adjustable panel 8 controlled by an actuating element 9, which makes it possible to precisely control the position of the casting blade 1, in particular, its distance from the movable base 2.

Between the casting blade 1 and the movable base 2 there is a gap, the dimensions of which determine, among other things, the thickness of the cast web of homogenized tobacco material.

The pulp distributor 5 for moving the pulp 18 into the casting box can have different positions and shapes. In the embodiment shown in FIG. 1, the pulp is fed from a single tubular channel, which is then divided into a plurality of tubes. The slurry flow in each exit tube is triangular in shape to allow adjustment and cover the full width of the mold box (similar to the exemplary diagram shown in Figures 6 and 7, for example). The slurry 18 drips in an intermittent manner from above directly into the casting box, as can be seen in figures 1, 2 and 3. During the dripping process, the drops of slurry 6 may or may not touch the side wall 3.

In addition, the casting box 10 contains a plurality of ribs. The fins are arranged in two substantially parallel first and second rows. Any number of rows is possible. The ribs of the first row are marked 12 and the ribs of the second row are marked 13. All the ribs of the first row and all the ribs of the second row are connected to each other by means of respective longitudinal rods 11, 11a, as shown in FIG. 2. The number of ribs in each row is such as to span a width of the casting box which is substantially equal to the width of the casting blade 1. Each rod 11, 11a has first and second ends which are connected to the side walls (not shown) of the casting box in such a way that that the ribs 12, 13 are securely connected to the casting box itself. The rods 11, 11a are fixed in such a way that the ribs face the hole 17 in the lower part of the casting box and thus also face the movable base 2.

The ribs in plan view form a C-shape, with the concave surfaces of the ribs in each row having the same orientation. In FIG. 4 clearly shows a row of ribs. Each rib 12, 13 is C-shaped, with the concave surface of this C oriented substantially towards the main pulp flow direction. The ribs 12, 13 are all of the same shape and all have a predominant dimension that is substantially parallel to the main pulp flow from where the pulp enters the mold box to the casting blade 1.

The first and second adjusting elements, shown schematically in FIG. 2, in the form of squares 30, 31, can act on the rods 11, 11a, changing the positions of the ribs. The first adjusting element 30 can rotate the ribs around the axis to change their orientation, and the second adjusting element 31 can change the height at which the fins are located. The distance between the ribs and the movable base can be changed using the second adjusting element. This height change is shown in Fig. 1 and FIG. 3. In FIG. 1 the fins are located closer to the movable base 2 than in FIG. 3.

In FIG. 4 shows the effect of the ribs on the pulp flow. The slurry flows towards the casting blade 1 and the ribs 12, 13 cause the slurry trajectory to curve and bend, whereby the flow is not linear.

In FIG. 5-7 show a second embodiment of a machine 101 for producing a cast sheet. The difference between the machine 100 and the present machine 101 relates to the arrangement of the ribs 12, 13. The ribs in this embodiment are fixed on the side wall 3 of the mold box 10. Preferably, the side wall 3 is inclined, i.e. it is not vertical but forms an angle with the vertical plane. . The pulp that falls from the pulp spreader 5 collides with the inner surface of the side wall 3 and slides over the surface in the direction of the moving base 2 and the casting blade 1. The ribs are located in the path of the pulp flow on the side wall 3. The ribs are located at two different heights, while the first row of ribs 12 is higher than the second row of ribs 13.

As shown in FIG. 6, the effect of the ribs 12, 13 on the pulp flow is the same as that of the ribs 12, 13 in the previous embodiment. The position of the ribs 12, 13 can also be changed due to the presence of the first and second adjusting elements (see Fig. 7).

In FIG. 8 shows a third embodiment of a sheet casting machine 102. In this embodiment, the ribs are arranged as in the first embodiment shown in FIG. 1-4, however, the pulp distributor 5 is different.

The fluid distributor 5 includes an inlet 90 which is formed on the side wall 3 of the mold box 10. Preferably, the fluid distributor 5 comprises a tube located substantially horizontally, so that in the hole (inlet 90) formed by the tube on the side wall 3, the direction of pulp flow is essentially horizontal.

With reference to FIG. 9, a fourth embodiment of the machine 103 is described. The casting box 10 in this embodiment also includes a lid 21. The lid 21 may be fixed or it may slide along the side walls 3, 4. The lid 21 forms opposite surfaces, called inner and outer 41, 42. The inner surface faces the pulp, while its outer part is on the opposite side. The cap may be in contact with the pulp. The walls and lid of the mold box 10 define the pressure vessel. A valve (or more than one valve) 23 is located on the outer surface of the lid 21 to allow the pressure value inside such a pressure vessel to be changed. The maximum allowable pressure on the valve 23 can be changed.

In addition, the first and second rows 12, 13 of ribs are arranged from the inner surface 41 of the cap towards the pulp 2. The two rows of ribs are preferably arranged parallel to each other and attached to the cap. On the opposite side of the lid, i.e., on the outer surface 42, adjustment devices, both designated 22, are available to the user, which can be used to rotate the fins 12, 13. The adjustment devices 22 may include a control knob.

The pulp is introduced into the casting box by means of a pulp distributor 5 made as in the third embodiment shown in FIG. eight.

Casting machine 101-103 operates as follows. Pulp 18, preferably obtained by mixing and combining tobacco powder and other ingredients, is transferred from a storage tank (not shown) by means of, for example, built-in agitators of the production line (also not shown), into the casting machine 100-103, in particular, inside the foundry boxes 10.

The slurry 18 is fed, for example, into an inlet 90 which is located on the rear/upstream side of the casting box 10 (on the side wall 3 of the casting box 10), and the casting blade 1 is located on the front/downstream side of the casting of the box 10, near the side wall 4. Alternatively, the slurry is distributed from above, for example, it enters the casting box through its open top and falls on the casting box or slides along the side wall 3. Along the casting direction 24, the slurry must pass through two rows ribs 12, 13, which are located essentially in the middle of the casting box 10 between the first and second walls 3, 4 (embodiments shown in Fig. 1, 8, 9). Alternatively, the ribs 12, 13 are arranged along the wall 3. The location of the ribs is controlled by actuating a control device 30, 31, 22 which can change the orientation of the ribs and their height.

In the case of a lid 21, the pressure inside the mold box 10 is controlled by positioning the lid 21 and control valve 23 or by allowing the lid to float on the surface of the slurry 18.

Next, the level of pulp in the mold box 10, as well as the moisture content of the pulp inside the mold box 10, and the density of the pulp 18 are monitored by means of suitable sensors.

The thickness of the web of homogenized tobacco material and the grammage, monitored by a nucleon sensor immediately after casting, are continuously measured and monitored with feedback by a pulp measuring device. Casting is carried out by means of a casting blade 1 forming a gap with the movable base 2, and this gap can also be controlled with feedback.

Next, the cast web is subjected to a drying step by means of a dryer (not shown in the drawings). The dryer comprises a plurality of separate drying zones. Each drying zone preferably has steam heating on the underside of the base and heated air above the movable base 2, as well as preferably adjustable air release controls. Inside the dryer, the homogenized tobacco web is dried to the desired final moisture content based on 2.

The drying step preferably includes uniform and gentle drying of the cast web in a stainless steel endless belt dryer with separately controlled zones. During the drying process, a step of monitoring the temperature of the cast web in each drying zone is carried out to ensure a smooth drying profile in each drying zone. The cast web is dried to the desired final moisture on the steel strip 2 by air drying from above and below with heating by means of a steam boiler. Each drying zone is equipped with steam flow and pressure controls, with air temperature and air flow fully adjustable to provide the desired drying profile and ensure product holding times are met.

Claims (26)

1. Casting machine for the production of a cast sheet of material containing alkaloids, containing a casting box configured to contain a slurry of material containing alkaloids; a pulp supply element configured to supply pulp to the casting box; moving base; a casting blade configured to cast the slurry contained in the casting box onto the movable base, thereby producing a cast web; redirecting ribs configured to come into contact with the pulp and placed inside the casting box. 2. The casting machine according to claim 1, characterized in that the redirecting ribs comprise a plurality of curved ribs. 3. The casting machine according to claim 2, characterized in that the plurality of curved ribs forms at least one row of curved ribs. 4. Casting machine according to claim. 3, characterized in that each curved rib from the specified set forms a concave surface, and the curved ribs of the same row have the same oriented concave surface. 5. Casting machine according to claim. 4, characterized in that the concave surfaces of the curved ribs in adjacent rows have the opposite orientation. 6. A casting machine according to one or more of the preceding claims, comprising a first adjusting element configured to rotate the redirecting ribs about an axis. 7. A casting machine according to one or more of the preceding claims, characterized in that said casting box contains a side wall, and containing a second adjusting element configured to change the distance between the redirecting ribs and the movable base or between the redirecting ribs and the side wall of the casting box. 8. A casting machine according to one or more of the preceding claims, characterized in that said casting box comprises a side wall and said redirecting ribs face the side wall of the casting box. 9. A casting machine according to one or more of the preceding claims, characterized in that said casting box contains an opening, while the movable base is located under the opening and said redirecting ribs face the movable base. 10. A method for producing a cast sheet of material containing alkaloids, including providing a casting box; providing a casting blade connected to the casting box; providing a movable base facing the casting blade; introduction of the pulp into the casting box; providing redirecting ribs within the mold box to bend the slurry flow path within the mold box; pouring the pulp onto a movable base by means of a casting blade. 11. The method of claim. 10, characterized in that the provision of redirecting ribs includes providing redirecting ribs facing the moving base. 12. The method according to claim 10 or 11, including adjusting the orientation of the redirecting ribs depending on the parameters of the pulp or cast sheet. 13. The method according to any one or more of paragraphs. 10-12, including adjusting the distance between the redirecting ribs and the movable base or between the redirecting ribs and the side wall of the casting box, depending on the parameters of the pulp or cast sheet. 14. The method according to claim 13, including the rotation of the redirecting ribs about an axis perpendicular to the movable base. 15. The method according to any one or more of paragraphs. 10-14, characterized in that the sheet of material containing the alkaloid contains a homogenized tobacco sheet.

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