METHOD AND APPARATUS FOR CUTTING FILTER MATERIALS

Description

[0001] The object of the invention is a method and an apparatus for cutting filter materials.

[0002] In the tobacco industry, particularly in the machines for manufacturing multi-segment filters used in cigarettes, there is a need of feeding multiple different filter segments from multiple feeding apparatuses. Among known segment feeding apparatuses are devices for feeding sets of filter segments, whereas one set of segments is formed by cutting one filter rod transported on a drum conveyor using a cutting head provided with rotary knives.

[0003] Systems for cutting filter materials into segments, in particular filter rods into segments used in multi-segment filters, where a number of individual segments with different physical properties is used, are known in the prior art. Rotary knife units, in particular made of steel, are utilised in the prior art.

[0004] In the Polish patent application P.394994, for example, the object of invention is a detachable cutting head for an apparatus for feeding filter segments provided with a drum conveyor having flutes for the transverse movement of filter rods, provided with rotary knives situated in knife units fastened in the housing of the head.

[0005] The object of invention in the Polish patent application P.395519 is a jacket for guiding filter segments to a filter segment feeding apparatus provided with a drum conveyor having flutes for the transverse movement of filter rods and a cutting head having multiple rotary knives fastened in the housing of the head, characterised by having a uniform, substantially cylindrical filter rod guiding surface. In addition, it has multiple slots for rotary knives of the cutting head.

[0006] From the GB 1043706 patent, a detachable cutting head provided with several rotary knives mounted on knife shafts is known.

[0007] An apparatus for cutting filter materials in the tobacco industry is known from DE 12 58 318 B.

[0008] In known filter rod cutting systems, no forced cooling systems are used because rotary knives made of steel easily give off heat to the air with ambient temperature. In the course of research on increasing the cutting speed, however, difficulties with the maintenance of the cutting surface quality occurred, whereas the quality of the cutting surface is mainly decreased by melting thereof. Such difficulties occurred in particular in case of the use of rotary knives made of tungsten carbide. Similar difficulties arose in case of the use of axially incompressible filter materials with a high hardness and of materials with the melting temperature in the range of 60°C. The purpose of the invention is to solve the problems which occur during filter material cutting with a high speed.

[0009] The gist of the invention is a method of cutting filter materials in the tobacco industry wherein by means of a drum conveyor provided on its circumference with flutes the filter material in the form of filter rods is fed to a rotary knife unit, the filter rods are cut into segments in the flutes of the drum conveyor in the area under a filter rod guiding jacket by means of rotary knives characterised in that the rotary knives are cooled in the area behind the guiding jacket.

[0010] Furthermore, a method of the invention is characterised in that the rotary knives are cooled to the temperature in the range between 5 and 25°C, preferably in the range between 15 and 25°C, and most preferably in the range between 20 and 25°C.

[0011] Furthermore, a method of the invention is characterised in that the rotary knives are cooled with compressed air, water, liquid nitrogen.

[0012] Furthermore, the rotary knives are cooled with a cooling medium in a closed cycle.

[0013] Furthermore, the rotary knives are cooled with a cooling medium in an open cycle.

[0014] Furthermore, the gist of the invention is an apparatus for cutting filter materials in the tobacco industry comprising a rotary knife unit provided with a filter rod guiding jacket for guiding filter rods conveyed in the flutes of the drum conveyor characterised in that in the area behind the guiding jacket a cooling unit reducing the temperature of the rotary knives is situated.

[0015] An apparatus of the invention is characterised in that the cooling unit comprises at least one cooling medium blowing nozzle for each knife.

[0016] An apparatus of the invention is characterised in that the cooling unit comprises two cooling medium blowing nozzles on two sides of a knife.

[0017] An apparatus of the invention is characterised in that the cooling medium nozzles are situated substantially perpendicular to the knife surface.

[0018] An apparatus of the invention is characterised in that the cooling medium nozzles are situated just at the cutting edges.

[0019] An apparatus of the invention is characterised in that the cooling unit operates in an open system.

[0020] An apparatus of the invention is characterised in that the cooling unit operates in a closed system.

[0021] An apparatus of the invention is characterised in that the rotary knife unit comprises rotary knives of tungsten carbide.

[0022] An apparatus of the invention is characterised in that the cooling unit is a unit for cooling with air, water or liquid nitrogen.

[0023] The substance of the invention is also an apparatus characterised in that a temperature sensor is assigned at least to one knife.

[0024] An advantage of the method and the apparatus according to the invention is the simplicity of design which allows performing filter material cutting at high speeds without worsening the physical characteristics of the filter material.

[0025] The object of the invention was shown in detail in a preferred embodiment in a drawing in which:

Fig. 1

diagrammatically shows an apparatus for cutting filter materials according to the invention.

Fig. 2

diagrammatically shows a view of a cooling head in an open configuration,

Fig. 3

diagrammatically shows a view of a cooling head in a closed configuration.

[0026] Fig. 1 diagrammatically shows an embodiment of the invention in a front, i.e. operator's, view. The drawing shows a drum conveyor 1 mounted on a plate 2 beneath a hopper 3. The drum conveyor 1 conveys filter rods 6 picked up from the hopper 3 in flutes 4 on the circumference 5 into the operating range of a rotary knife 8 unit 7. The filter rods 6 are placed into the space between the drum conveyor 1 and a guiding jacket 12 where they are cut by means of the rotary knives 8. The rotary knives 8 are situated with their axes of rotation 9 parallel to the axis of rotation 10 of the drum conveyor 1, whereas their cutting edges 11 go through the guiding jacket 12 in order to allow cutting of the rods 6 in the flutes 4. The rotary knives 8 are partly disposed in a cooling area 15 marked with a broken line and situated behind the guiding jacket 12. In the cooling area 15, cooling members 16 of a cooling head 17 preferably made of aluminium are situated, whereas to each knife at least one cooling member 16 is assigned. The cooling members 16 are members supplying a cooling medium to the cooling area 15. The cooling members 16 can be for example compressed air or gas nozzles; they can also supply a different cooling medium. The cooling of the cooling head 17 using ice-cold water, i.e. water with additives lowering its freezing point below 0°C, can also be designed. Also temperature sensors 18 are placed in the cooling head, whereas at least one temperature sensor 18 at one of the rotary knives 8 is designed in the cooling head. Fig. 2 shows a diagrammatic view of the rotary knives 8 and the cooling head 17 from the side of the drum conveyor 1.

[0027] During the operation of the apparatus, the rotary knives 8 cut the filter rods into segments, and their cutting edges and border heat up to a temperature depending on the kind of filter material being cut. For the purpose of stabilizing the temperature of rotary knives 8, cooling members 16 situated in fragments 19 of the cutting head 17 comprising or adjacent to a portion of the surface of rotary knives 8 have been designed in the cooling area 15. The cooling medium will flow to the cooled knives 8 in slots 13 between the fragments 19 of the cooling head 17 and the rotary knives 8. The function of the head 17 is to stabilize the temperature of the rotary knives during their operation. The cooling head 17 fulfils the function of a heat exchanger to which through feeders 21 the cooling medium from a cooling medium source 20 also used as a system for conditioning, i.e. cooling down and compressing, the cooling medium is supplied. An open cooling system shown in Fig. 2 is possible where the cooling medium, for example compressed air with a low temperature, is released to the environment. A cooling system in a closed configuration shown in Fig. 3 is also possible where the cooling medium is supplied through the feeders 21 to the nozzles 16. However, the heated cooling medium is carried from the slots 13 through drains 22 to the cooling medium source 20, whereas the medium is not released to the atmosphere.

[0028] In view of the costs, the preferred embodiment of the invention is a system with a closed cooling medium circulation.

[0029] In the preferred embodiments such cooling mediums as compressed air, water, liquid nitrogen are possible.

[0030] In the course of the research work, it was unexpectedly observed that cooling down of the rotary knives of tungsten carbide to the temperature of 25°C brought favourable effects for the quality of the filter material cutting process.

[0031] During the conducted research it turned out that it was possible to stabilize the temperature of the knives in the range between 5°C and 25°C. Preferably, the temperature was maintained in the range between 15°C and 25°C, and most preferably in the range between 20°C and 25°C.

Claims

1. A method of cutting filter materials in the tobacco industry wherein:

by means of a drum conveyor provided on its circumference with flutes the filter material in the form of filter rods is fed to a rotary knife unit;

the filter rods are cut into segments in the flutes of the drum conveyor in the area beneath a filter rod guiding jacket by means of rotary knives,

characterised in that

the rotary knives are cooled in the area behind the guiding jacket.

2. A method as in claim 1 characterised in that the rotary knives are cooled to the temperature in the range between 5 and 25°C, preferably in the range between 15 and 25°C, and most preferably in the range between 20 and 25°C.

3. A method as in claim 1 or 2 characterised in that the rotary knives are cooled with a cooling medium selected from a group comprising: compressed air, water, liquid nitrogen.

4. A method as in claim 1 to 3 characterised in that the rotary knives are cooled with a cooling medium in a closed cycle.

5. A method as in claim 1 to 3 characterised in that the rotary knives are cooled with a cooling medium in an open cycle.

6. An apparatus for cutting filter materials in the tobacco industry comprising
a rotary knife unit provided with a filter rod guiding jacket for guiding filter rods conveyed in the flutes of a drum conveyor,
characterised in that
in the space behind the guiding jacket a cooling unit lowering the temperature of the rotary knives by means of a cooling medium is situated.

7. An apparatus as in claim 6 characterised in that the cooling unit comprises at least one cooling medium blowing nozzle for each knife.

8. An apparatus as in claim 6 characterised in that the cooling unit comprises two cooling medium blowing nozzles on two sides of a knife.

9. An apparatus as in claim 7 or 8 characterised in that the cooling medium nozzles are situated substantially perpendicular to the knife surface.

10. An apparatus as in any of the claims 7 to 9 characterised in that the cooling medium nozzles are situated just at the cutting edges.

11. An apparatus as in any of the claims 6 to 10 characterised in that the cooling unit operates in an open system.

12. An apparatus as in any of the claims 6 to 10 characterised in that the cooling unit operates in a closed system.

13. An apparatus as in any of the claims 6 to 13 characterised in that the cooling unit is a unit for cooling with air, water or liquid nitrogen.

14. An apparatus as in any of the claims 6 to 13 characterised in that a temperature sensor is assigned at least to one knife.

15. An apparatus as in any of the claims 6 to 14 characterised in that the rotary knife unit comprises rotary knives of tungsten carbide.

Ansprüche

1. Verfahren zum Schneiden von Filtermaterial in der Tabak verarbeitenden Industrie:

bei welchem das Filtermaterial in Form von Filterstäben mittels eines an seinem Umfang mit Nuten versehenen Trommelförderers einer Drehmessereinheit zugeführt wird; und

die Filterstäbe in den Nuten des Trommelförderers im Bereich unterhalb einer Filterstab Führungshülle mittels Drehmesser in Stücke geschnitten werden,

das dadurch gekennzeichnet ist, dass

die Drehmesser im Bereich hinter der Führungshülle gekühlt werden.

2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, dass die Drehmesser auf eine Temperatur im Bereich zwischen 5 und 25°C, bevorzugt im Bereich zwischen 15 und 25°C, und besonders bevorzugt im Bereich zwischen 20 und 25°C gekühlt werden.

3. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass die Drehmesser mit einem Kühlmedium gekühlt werden, das aus der Gruppe ausgewählt ist: Druckluft, Wasser, Flüssigstickstoff

4. Verfahren nach Anspruch 1 bis 3, dadurch gekennzeichnet, dass die Drehmesser mit einem Kühlmedium in einem geschlossenen Kreislauf gekühlt werden.

5. Verfahren nach Anspruch 1 bis 3, dadurch gekennzeichnet, dass die Drehmesser mit einem Kühlmedium in einem offenen Kreislauf gekühlt werden.

6. Vorrichtung zum Schneiden von Filtermaterialien in der Tabak verarbeitenden Industrie, bestehend aus
einer Drehmessereinheit, welche mit einer Filterstab Führungshülle zur Führung der Filterstäbe in den Nuten eines Trommelförderers versehenen ist,
die dadurch gekennzeichnet ist, dass
im Raum hinter der Führungshülle eine Kühleinheit ist, welche die Temperatur der Drehmesser mit Hilfe eines Kühlmediums reduziert.

7. Vorrichtung nach Anspruch 6, dadurch gekennzeichnet, dass die Kühleinheit zumindest eine Blasdüse für jedes Messer enthält.

8. Vorrichtung nach Anspruch 6, dadurch gekennzeichnet, dass die Kühleinheit zwei Kühlmedium-Blasdüsen an zwei Seiten eines Messers enthält.

9. Vorrichtung nach Anspruch 7 oder 8, dadurch gekennzeichnet, dass die Kühlmedium-Blasdüsen im Wesentlichen senkrecht zur Messerfläche angeordnet sind.

10. Vorrichtung nach einem der Ansprüche 7 bis 9, dadurch gekennzeichnet, dass die Kühlmedium-Blasdüsen nur an den Schneidkanten angeordnet sind.

11. Vorrichtung nach einem der Ansprüche 6 bis 10, dadurch gekennzeichnet, dass die Kühleinheit in einem offenen System arbeitet.

12. Vorrichtung nach einem der Ansprüche 6 bis 10, dadurch gekennzeichnet, dass die Kühleinheit in einem geschlossenen System arbeitet.

13. Vorrichtung nach einem der Ansprüche 6 bis 13, dadurch gekennzeichnet, dass die Kühleinheit eine Einheit zum Kühlen mit Luft, Wasser oder Flüssigstickstoff ist.

14. Vorrichtung nach einem der Ansprüche 6 bis 13, dadurch gekennzeichnet, dass ein Temperatursensor zumindest einem Messer zugeordnet ist.

15. Vorrichtung nach einem der Ansprüche 6 bis 14, dadurch gekennzeichnet, dass die Drehmessereinheit Messer aus Wolframkarbid enthält.

Revendications

1. Un procédé de coupe de matériaux de filtres destinés à l'industrie du tabac, dans lequel:

au moyen d'un convoyeur à tambour muni sur sa périphérie de cannelures permettant l'introduction des matériaux de filtres sous la forme de batônnets-filtres dans une unité de lames rotatives ;

les batônnets-filtres sont coupés en segments dans les cannelures du convoyeur à tambour au moyen de lames rotatives, au-dessous d'une gaine de guidage des batônnets-filtres,

caractérisé par le fait que

les lames rotatives sont refroidies dans la zone se trouvant derrière la gaine de guidage.

2. Un procédé, comme dans la Revendication 1, caractérisé par le fait que les lames rotatives sont refroidies à une température entre 5 et 25° C, de préférence entre 15 et 25° C, et plus particulièrement entre 20 et 25° C.

3. Un procédé, comme dans la Revendication 1 ou 2, caractérisé par le fait que les lames rotatives sont refroidies avec un agent de refroidissement parmi un groupe comprenant : l'air comprimé, l'eau, l'azote liquide.

4. Un procédé, comme dans la Revendication 1 à 3, caractérisé par le fait que les lames rotatives sont refroidies avec un agent de refroidissement dans un cycle fermé.

5. Un procédé, comme dans la Revendication 1 à 3, caractérisé par le fait que les lames rotatives sont refroidies avec un agent de refroidissement dans un cycle ouvert.

6. Un appareil pour couper des matériaux de filtres dans le cadre de l'industrie du tabac, comprenant
une unité de lames rotatives munie d'une gaine de guidage des batônnets-filtres pour les orienter dans les cannelures d'un convoyeur à tambour,
caractérisé par le fait qu'
une unité de refroidissement qui abaisse la température des lames rotatives au moyen d'un agent de refroidissement est située derrière la gaine de guidage.

7. Un appareil, comme dans la Revendication 6, caractérisé par le fait que l'unité de refroidissement comprend au moins une buse de soufflage d'agent de refroidissement pour chaque lame.

8. Un appareil, comme dans la Revendication 6, caractérisé par le fait que l'unité de refroidissement comprend au moins deux buses de soufflage d'agent de refroidissement sur les deux côtés d'une lame.

9. Un appareil, comme dans la Revendication 7 ou 8, caractérisé par le fait que les buses d'agent de refroidissement sont sensiblement perpendiculaires à la surface des lames.

10. Un appareil, comme dans l'une des Revendications 7 à 9, caractérisé par le fait que les buses d'agent de refroidissement sont situées juste au niveau des bords des lames.

11. Un appareil, comme dans l'une des Revendications 6 à 10, caractérisé par le fait que l'unité de refroidissement fonctionne dans un système ouvert.

12. Un appareil, comme dans l'une des Revendications 6 à 10, caractérisé par le fait que l'unité de refroidissement fonctionne dans un système fermé.

13. Un appareil, comme dans l'une des Revendications 6 à 13, caractérisé par le fait que l'unité de refroidissement utilise l'air, l'eau ou l'azote liquide.

14. Un appareil, comme dans l'une des Revendications 6 à 13, caractérisé par le fait qu'un capteur de température est affecté à au moins une lame.

15. Un appareil, comme dans l'une des Revendications 6 à 14, caractérisé par le fait que l'unité de lames rotatives comprend des lames en carbure de tungstène.

Drawing