EP0345477A2 - Method and apparatus for making pieces of tobacco sheets from reconstituted tobacco - Google Patents

Abstract

In a method and an apparatus for making pieces of tobacco sheets from reconstituted tobacco, tobacco wastes in dust form and/or ground tobacco are mixed with binders and optional additives; the mixture obtained is divided into an even number of mechanically/geometrically identical cylindrical rods; each pair of adjacent rods are rolled together to form a sheet strip which is then cut to give the pieces of sheets. <IMAGE>

Description

The invention relates to a method for producing tobacco foil pieces from reprocessed tobacco of the type specified in the preamble of claim 1 and a device for producing tobacco foil pieces from reprocessed tobacco of the type specified in the preamble of claim 6.

In the manufacture of tobacco foil pieces from dust-like tobacco waste and / or tobacco flour, it is known to extrude a foamed product from these starting materials, see DE-OS 25 15 496, DE-OS 33 11 886 and EP-OS 113 595. A disadvantage is the relatively high need for binders, especially starch, which cause sensory problems. In addition, the often used additive hydroxypropyl / ethyl cellulose is not approved in a number of countries. And finally, a large expenditure on equipment is required if, as in DE-OS 2 515 496, inert gases are injected to increase the expansion.

Furthermore, the extrusion of a film by means of a slot die is described in US Pat. No. 3,098,492 and DE-OS 2 804 772; such a wide slot nozzle is, however, complex and expensive.

Because of the risk of blockage of such a slot die, considerable demands must be placed on the tobacco raw material.

The grain size of the starting material must, for example, be chosen so that practically no particle is larger than the gap width of the slot die, otherwise it would jam in the gap and act as a germ for a blockage of the nozzle.

On the other hand, since the filling capacity of the tobacco film depends crucially on the smallest possible thickness corresponding to a small nozzle gap width, the entire tobacco starting material must be ground and then sieved.

In addition, the production of a film by extrusion of the starting material by means of a slot die into a roll nip is known, see US Pat. No. 30 98 492, DE-OS 28 04 772 and GB Pat. No. 14 59 218. Here, too, the above-mentioned disadvantages of the complex arise Slot die; in addition, the rolls forming the gap run only slowly, so that a high torque is required, which leads to great stress on the roll construction with a relatively low throughput. An increase in throughput can only be achieved by increasing the roll width; this in turn requires an extremely large slot die, a stable roll structure and a large roll thickness to minimize deflection. In addition, a multiple calender must usually be used because a single forming step is not sufficient to achieve the required thickness.

Furthermore, it is known to produce tobacco films by means of rollers, see DE-OS 31 04 098, DE-PS 20 55 672, DE-PS 24 21 652 and DE-PS 32 24 416 and GB-PS 1 459 218. However, one must do this extremely strong humidification of the starting material in the range of 30 to 50%, so that a subsequent drying is required.

This in turn increases the process engineering effort. In addition, undesirable organic solvents are often used here, e.g. Methylene chloride; and finally a multi-stage rolling mill or calender is usually required.

A method and a device for producing tobacco foil pieces from reprocessed tobacco of the type specified are finally known from DE-PS 33 39 247. Dust-like tobacco waste and / or tobacco flour with binders and optionally additives are processed to a plastifiable mixture which is extruded into individual, strand-like intermediate products. These strand-like intermediate products are then processed into pieces of film by forming a cylindrical strand from the plasticized mixture in an extruder into a thin-walled, continuously expanding hollow body and dividing it into thread-like, crimping intermediate products; the thread-like, crimped intermediate products are then separated into individual, crimped fiber pieces.

The disadvantage here is that these crimped fiber pieces can only be added separately to the tobacco preparation during cut tobacco production by means of a separate metering device; This requires a relatively high outlay in terms of apparatus with an appropriate carton emptying device, a filler, a belt scale, etc., since only precisely defined amounts of these crimped fiber pieces, based on the total amount of tobacco to be processed, may be metered in.

The invention is therefore based on the object of providing a method and a device for producing pieces of tobacco foil from refurbished tobacco of the type specified, in which the disadvantages mentioned above do not occur.

In particular, a method and a device are to be proposed which allow the production of Ta Allow pieces of bakery film, with particularly low demands being placed on the quality of the starting material, so that, for example, dust-like tobacco waste which arises in the manufacture of cigarettes can be processed into film without further pretreatment.

This is achieved according to the invention by the features specified in the characterizing parts of claims 1 and 6, respectively.

Expedient embodiments are defined by the features of the corresponding subclaims.

The advantages achieved with the invention are based on the following mode of operation: The individual starting components, namely dust and / or flour from tobacco parts, in particular tobacco waste, binders, in particular starch, CMC, vegetable gum, pectin or other conventional film binders, and further additives, in particular taste improvers, fire modifiers etc., are dry mixed together in the usual manner; Then the liquid components are added, namely water, humectant, sugar syrup etc. This free-flowing starting material due to the low water content of 16-20% by weight is mixed intensively with one another and then in an extruder at temperatures from 90 ° C to 120 ° C and pressures plasticized from 50 to 100 bar.

The plasticized mass produced in this way is then divided into several cylindrical strands with a diameter of 2 to 7 mm, in particular with a diameter of 3 to 5 mm, by the extruder nozzle. It is important that the distribution of the starting material among the different strands is carried out over flow paths of exactly the same length, so that the same flow velocity of the individual strands is achieved via the identical pressure losses that occur. The division must be carried out in pairs, so that a total of an even number, as represented by a power of 2, arises.

These procedural measures ensure that each adjacent, simultaneously manufactured pair of strands is mechanically / geometrically identical.

The various cylindrical strands are then rolled out together to form foil strips, two adjacent strands, which, as mentioned, are mechanically / geometrically identical, being rolled together to form a single foil strip / strip. This band has a width of 10 to 100 mm, preferably 20 to 50 mm; the value used should be selected so that the strip width corresponds to the narrower edge length of the finished, rectangular piece of film.

The rolling together of the two adjacent strands into a single film strip can be carried out in one step and therefore requires only a small outlay on equipment; since the circumferential roller speed is relatively high, only a low torque and therefore a low motor power is required. This has to be compared with the previously extremely complex calender rolling mills.

Since there are no extremely high demands on the dimensions of the film strips, a simply constructed rolling mill can be used, such as is used, for example, as a roller mill for crushing brittle materials and is available in many different, inexpensive embodiments. The rollers are pressed together by threaded spindles to a gap thickness of 0 mm, the counterforce being generated by a plate spring assembly. The film thickness is then adjusted to a value of 0.1 to 0.25 mm, in particular 0.18 to 0.22 mm, by means of a balance of spring force and the deformation resistance which results from the rheological properties of the plasticized tobacco mass.

The speed of the rollers is adjusted as a function of and in adaptation to the extrusion speed of the extruder so that continuous film strips are produced. It has proven to be expedient if the two rollers have different speeds, since the film strip then sticks to the faster roller and can be easily removed there. In this way it is avoided that the film strip can stick to both rollers and is thereby torn.

The surface of the two rollers should be hardened and borated or hard metal coated.

In order to support the separation of the film strips from the rollers, the surfaces of the rollers can be sprayed with water and / or steam as a release agent.

For the rolling together of the different pairs of strands, only a single pair of rollers is required, which has the required length. This also contributes to the desired low expenditure on equipment.

The two rollers stand on a displaceable frame which can be pushed back and forth by an eccentric drive, expediently in a continuous back and forth movement, so that the strands emitted by the extruder nozzle are distributed uniformly over the entire surface of the rollers and thereby the surface wear spread over the entire roller surface.

The film belts leaving the nip are pulled off by a speed-adjustable conveyor belt at the same speed in each case and then cut into pieces of 10 to 100 mm, preferably 30 to 50 mm, in length. For this purpose, the film strips are sucked together with the ambient air through a cross cutting device, cut transversely and then pneumatically transported on.

Here, a "lawn mower-like" cross cutting device is used, which can simultaneously cut several foil strips into pieces of the desired length, the cutting length being adjustable via the speed of the cutting device.

If the initial mass is suitably moist, the film pieces no longer need to be dried; However, the pieces of film are expediently cooled to room temperature in order to avoid the formation of condensation water during storage.

• Fig. 1 eine Schemadarstellung der verschiedenen Komponenten einer Vorrichtung zur Herstellung von Tabakfolienstücken aus wie­deraufbereitetem Tabak,
• Fig. 2 das Fließschema der Extruderdüse, und
• Fig. 3 eine perspektivische Ansicht der Querschneideeinrichtung.

The invention is explained in more detail below using exemplary embodiments with reference to the accompanying schematic drawings. Show it:

• 1 is a schematic representation of the various components of a device for producing tobacco foil pieces from reprocessed tobacco,
• Fig. 2 shows the flow diagram of the extruder nozzle, and
• Fig. 3 is a perspective view of the cross cutting device.

1, generally indicated by the reference numeral 10, for producing tobacco foil pieces from recycled tobacco has a plurality of containers 12, 14, 16 18, 20 with the starting materials, namely a container 12 for water, a container 14 for binders, namely starch, CMC, vegetable gum, pectin or other conventional film binders, a container 16 for dust and / or flour from tobacco parts, in particular tobacco waste, a container 18 for additives such as taste improvers, fire modifiers, etc., and finally a container 20 for a humectant , Sugar syrup or other liquid components.

First, the dry components from the containers 14 to 18 are premixed in a mixer 22, to which the liquid components from the containers 12 and 20 are then fed, so that the entire raw raw material can be mixed thoroughly.

The mixed raw raw material is fed to an extruder 24, which the raw raw material at temperatures from 90 ° C to 120 ° C. and pressures of 50 to 100 bar kneaded and thereby plasticized.

The plasticized mass from the extruder 24 is divided by the schematically indicated extrusion nozzle 26 into a plurality of cylindrical strands with a diameter of 2 to 7 mm, in particular with a diameter of 3 to 5 mm. It is important that the distribution of the mass takes place over flow paths of exactly the same length, so that the individual strands have the same flow velocity due to the same pressure losses. This in turn means that the individual strands produced simultaneously are mechanically / geometrically identical.

This basic principle is shown in Fig. 2; The plasticized tobacco mass located at point X of the extruder 24 is, as can be seen from FIG. 2, divided into two flow paths of equal length, which in turn are divided into two further flow paths A or B and C or D, so that the strands A, B on the one hand and C, D on the other hand are each mechanically / geometrically identical.

These strands are again divided using the same flow paths, specifically to the strands at the outlet channels A1, A2, B1, B2, C1, C2, D1 and D2.

Because of the same flow paths, the distance from the inlet X to the outlet channel A1 of the extruder nozzle 26 is equal to the flow path from the inlet X to the outlet channel A2.

The other exit channels A1, A2, B1, B2, C1, C2, D1 and D2 are also identical to one another. That is, for example, the strand on the outlet channel C1 is identical to the strand on the outlet channel D2.

All exit strands can have a cylindrical shape, ie exit channels with a circular cross-section that can be produced inexpensively are used in each case.

The cylindrical strands from the different outlet channels of the extrusion nozzle 26 are each rolled out in pairs to form foil strips, two adjacent strands, for example the strands from the extrusion channels A1 and A2, being rolled together to form a foil strip. The corresponding rolling mill is indicated schematically at 28.

In one embodiment, the two rolls 28a, 28b of this rolling mill 28 have a diameter of 250 mm and a width of 150 mm and run at a speed of 3 m / s.

The two rollers 28a, 28b are first pressed together to a gap thickness of 0 mm by means of a threaded spindle (not shown). The counterforce is generated by a plate spring assembly (not shown). The film thickness is adjusted via a balance of spring force and deformation resistance of the plasticized tobacco material to a value of 0.1 to 0.25 mm, in particular 0.18 to 0.22 mm.

The roller speed is set so that 24 continuous film strips result in adaptation to the output power of the extruder.

The surfaces of the two rollers 28a, 28b are hardened and borated or else provided with a hard metal coating. They are sprayed with water and / or steam as a release agent in order to facilitate the final separation of the film strips from the rollers 28a, 28b.

The rolling mill 28 stands on a displaceable frame and is pushed back and forth in the axial direction by an eccentric drive, so that the film strips come into contact with different places on the roll surfaces one after the other and the surface wear is thereby distributed over the entire roll surface.

The film strips produced in the rolling mill 28 have a width of 10 to 100 mm, in particular 20 to 50 mm, so that the strips width corresponds to the narrower edge length of the rectangular pieces of film to be explained.

The two rollers 28a, 28b have slightly different speeds, so that the film strips adhere to the faster roller and thereby prevent the film strips from being torn between the two rollers 28a, 28b. In the embodiment shown, the roller 28a runs somewhat faster, so that the film strips pulled off in the direction of the arrow are carried along by this roller and then placed on a speed-adjustable conveyor belt 30.

Although it is not shown in FIG. 1, the device 10 according to FIG. 1 simultaneously produces a plurality of film strips with the desired width. If, for example, the extruder nozzle 26 according to FIG. 2 is used for the production of a total of eight cylindrical strands, four foil strips can be rolled out simultaneously.

The tobacco foils are fed from the conveyor belt 30 to a cross cutting device 32, which cuts the belts into pieces with a length of 10 to 100 mm, in particular 30 to 50 mm. Because of the high transport speeds of the film strips, the usual cross cutting devices, such as knives, are not suitable for this separation, so that instead a lawn mower-like cross cutting device 32 is used, the construction of which can be seen in FIG. 3.

The cross cutting device 32 has a cylindrical housing 34 in which two rotor disks 38 are rotatably mounted. The right-hand rotor disk 38 as shown in FIG. 3 is connected to a rotor shaft 36 which can be rotated in the direction of the arrow by means of a drive device (not shown) and thereby also rotates the other rotor disk.

The two rotor disks 38 are connected to one another by obliquely extending cutting strips 40, which act on the rotation of the two rotors slices 38 to be taken. A fixed cutting bar 42 is located on the bottom of the housing 34.

The film strips supplied by the conveyor belt 30 are sucked pneumatically into the opening slot of the housing 34 and transported through the housing 34, whereby they are guided over the fixed cutting bar 42. When the two rotor disks 38 are rotated, the individual cutting strips 40 are guided past the fixed cutting strip 42 and separate pieces of tobacco film, the lengths of which depend on the conveying speed of the film strip on the one hand and the rotational speed of the rotor disks 38 and thus the cutting strips 40 on the other hand. With the appropriate setting, pieces of tobacco foil of the desired length can be produced. These pieces are in the direction of the dashed arrow out of the housing 34 of the cutting device 32 and fed to further processing, namely first of all a cooling unit, so that the formation of condensed water during storage is avoided, then the packaging, the storage and finally the supply to the tobacco preparation.

If the moisture of the raw raw material is outside the specified range, it may be necessary to provide an additional drying step.

Claims (15)

1. Process for producing tobacco foil pieces from reprocessed tobacco, a) mixing dusty tobacco waste and / or tobacco flour with binders and optionally additives, b) in which the mixture obtained is plasticized in an extruder and formed into at least one cylindrical strand, and c) in which the cylindrical strand is processed into pieces of film, characterized by the following features: d) the plasticized mixture is divided into an even number of mechanically / geometrically identical cylindrical strands; e) two adjacent, identical strands are rolled together to form a film strip; and f) the film strip is cut into pieces of film. 2. The method according to claim 1, characterized in that the plasticization of the mixture in the extruder at temperatures of 90 ° C to 120 ° C and pressures of 50 to 100 bar. 3. The method according to any one of claims 1 or 2, characterized in that cylindrical strands with a diameter of 2 to 7 mm, preferably a diameter of 3 to 5 mm, are made. 4. The method according to any one of claims 1 to 3, characterized in that the mixture is divided into exactly the same long flow paths in the individual cylindrical strands. 5. The method according to any one of claims 1 to 4, characterized in that the film strips are cut in the transverse direction. 6. Device for producing tobacco foil pieces from reprocessed tobacco a) with a mixer for dust-like tobacco waste and / or tobacco flour, binders and optionally additives, b) with an extruder for plasticizing the mixture obtained and for producing at least one cylindrical strand, and c) with a device for processing the cylindrical strand into pieces of tobacco foil,
characterized in that d) the extruder nozzle (26) divides the mixture into an even number of mechanically / geometrically identical strands that can be represented as a power of two (2 ⁿ ) that e) the extruder nozzle (26) is followed by a pair of rollers (28; 28a, 28b), each of which rolls two adjacent cylindrical strands together to form a film strip, and that f) a cross cutting device (32) is provided for the film strips. 7. The device according to claim 6, characterized in that the two rollers (28a, 28b) have different speeds. 8. Device according to one of claims 6 or 7, characterized in that the extruder nozzle (26) has exactly the same length of flow paths for the different strands. 9. Device according to one of claims 6 to 8, characterized by a device for spraying the rollers (28a, 28b) with water and / or steam as a release agent. 10. Device according to one of claims 6 to 9, characterized in that a roller mill is used. 11. The device according to one of claims 6 to 10, characterized by a spring assembly, in particular a plate spring assembly, for generating the contact force for the two rollers (28a, 28b). 12. Device according to one of claims 6 to 11, characterized in that the rollers (28a, 28b) are mounted on a displaceable frame. 13. Device according to one of claims 6 to 12, characterized in that the roller pair (28 28a, 28b) is followed by a speed-controllable conveyor belt (30) for feeding the film belts to the cross-cutting device (32). 14. Device according to one of claims 6 to 13, characterized in that the cross cutting device has a fixed cutting bar (42) and rotating cutting bars (40) mounted on the circumference of rotatable rotor disks (38). 15. The apparatus according to claim 14, characterized in that the cross cutting device (32) has a housing (34) through which the film strips or the cut pieces of film are transported pneumatically.

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