A method for manufacturing tobacco rods and a machine for manufacturing tobacco rods incorporating a device for pneumatically extracting a continuous rod from a forming unit

Abstract

A machine (1, 2) for producing tobacco industry rods (R), the machine comprising: at least one feeding unit (3) for supplying filling material (12, 14) for the continuous rod (CR), at least one delivery unit (7) for providing a strand of wrapping material (6) for wrapping the filling material of the continuous rod (CR), at least one glue applicator (9) for applying glue to the wrapping material (6) or to the filling material (12, 14) for the continuous rod (CR), a forming unit (8) for forming the continuous rod (CR) from the wrapping material (6) and the filling material (12, 14), and a cutting head (11) for cutting the continuous rod (CR) into rods (R) of a specified length, characterized in that the machine further comprises a pneumatic linear conveyor (10) for pneumatically extracting the continuous rod (CR) from the forming unit (8), located between the forming unit (8) and the cutting head (11).

Description

[0001] A METHOD FOR MANUFACTURING TOBACCO RODS AND A MACHINE FOR MANUFACTURING TOBACCO RODS INCORPORATING A DEVICE FOR PNEUMATICALLY EXTRACTING A CONTINUOUS ROD FROM A FORMING UNIT

[0002] TECHNICAL FIELD

[0003] The present invention relates to a method for manufacturing tobacco industry rods and a machine for manufacturing tobacco industry rods, provided with a device for pneumatically extracting a continuous rod from a forming unit.

[0004] BACKGROUND

[0005] The present invention is relevant to the tobacco industry, specifically to machines for manufacturing various types of tobacco rods having a finite length. These include rods made from continuous filter fiber, as well as multi-segment rods, composed of a series of segments with differing properties.

[0006] In the tobacco industry, it is common to manufacture smoking or heating tobacco articles provided with a tobacco part, a filter, and segments performing functions such as imparting aroma, cooling tobacco smoke, and providing rigidity to the rod. A typical method of manufacturing such articles involves forming a continuous rod filled with a filling material, typically a fibrous material such as acetate, crepe or cut paper, or possibly another material based on various plastics or plant material other than cellulose performing filtering functions, or segments of a certain length. The filling material is then wrapped in a wrapping material to form a continuous rod, which is subsequently cut into individual rods.

[0007] The challenge for manufacturers of these rods is to maintain high product quality while ensuring high productivity of the manufacturing machines. High machine productivity can be achieved, among other things, by minimizing the number and duration of production interruptions. Interruptions on rod manufacturing machines are often caused by the continuous rod blocking in the garniture bar due to the reversal of one of the segments or uneven diameter of the rod, or by the accumulation of dirt from glue and dust in the duct of the garniture bar. This increases the resistance of the continuous rod to flow through the channel of the garniture bar, causing the channel to become blocked, and the rod to break or deform. Another reason for machine interruption is the breaking or bending of the continuous rod after exiting the garniture bar, where the rod is no longer supported, which may be due to an under-occlusion of the wrapper on the glue seam or a deformation formed in the duct of the garniture bar.

[0008] To mitigate the above problem and minimize interruption, a device configured to extract the continuous rod from the garniture bar can be used. With such a device, even if the continuous rod is deformed, damaged or dirty after exiting the garniture bar, it will not cause the machine to stop, because the continuous rod will be supported and transported towards the cutting head in a contactless manner, and the rod with such a defect will be rejected in the subsequent quality control process.

[0009] In the prior art, various devices are known for extracting the continuous rod from the garniture bar. For example, GB1083088 discloses a cigar manufacturing machine using a device for extracting a continuous rod from a forming device. The device comprises a first and second set of rollers with a concave contact surface. The rollers press against the rod on opposite sides and, through a drive supplied to them, make a rotary motion, thereby causing the rod to be extracted from the forming device.

[0010] GB2171168 discloses a rod-forming device used in cigarette filters. The tube is formed on the forming unit, from at least one strand of material by wrapping it around a fixed forming mandrel, from which it is then moved toward the cutting head by means of a scrolling belt in the groove of the forming unit. Behind the forming unit is a set of driven rollers that extracts the continuous tube from the forming unit through frictional force.

[0011] Devices known from the prior art that use rollers do not solve the problem of manufacturing high-quality rods. Extracting rollers work by contacting their peripheral surface with the outer surface of a continuous rod. To exert an extracting force, it is necessary to press the rollers against the outer surface of the rod with such force that friction is created between the two surfaces. This can cause permanent deformation of the continuous rod, especially if the manufactured rod contains vulnerable segments or voids between the segments (so-called “cavities”), or can cause dirt to be deposited on the contact surface of the rollers.

[0012] SUMMARY

[0013] The aim of the present invention is to provide a machine for manufacturing high- quality tobacco rods while minimizing the number of production stops caused by blockage of the forming unit or breaking of the continuous rod after exiting the forming unit. The object of the invention is a machine for producing tobacco industry rods, the machine comprising: at least one feeding unit for supplying filling material for the continuous rod, at least one delivery unit for providing a strand of wrapping material for wrapping the filling material of the continuous rod, at least one glue applicator for applying glue to the wrapping material or to the filling material for the continuous rod, a forming unit for forming the continuous rod from the wrapping material and the filling material, and a cutting head for cutting the continuous rod into rods of a specified length. The machine further comprises a pneumatic linear conveyor for pneumatically extracting the continuous rod from the forming unit, located between the forming unit and the cutting head.

[0014] The pneumatic linear conveyor may have a body with an elongated duct for guiding the continuous rod, the duct may have an inlet located at the outlet of the forming unit and an outlet located at the cutting head, and the duct may have a supply of compressed gas forming an air bearing around the continuous rod.

[0015] The diameter of the duct of the pneumatic linear conveyor may be 15 to 60% larger than the diameter of the continuous rod.

[0016] The pneumatic linear conveyor may generate a force acting on the continuous rod axially longitudinally in the direction of the cutting head.

[0017] The pneumatic linear conveyor may extract the continuous rod in a contactless manner.

[0018] The pneumatic linear conveyor may support the continuous rod in a contactless manner.

[0019] The pneumatic linear conveyor may generate a force in the range from 1 N to 70N.

[0020] A compressed gas may be supplied to the pneumatic linear conveyor under pressure of 2 to 6 bar.

[0021] The outlet of the duct of the pneumatic linear conveyor may be positioned at a distance in the range from 5mm to 100mm from the knife of the cutting head.

[0022] The compressed gas may be let into the duct of the pneumatic linear conveyor circumferentially in relation to the longitudinal axis of the duct.

[0023] The compressed gas may be let into the duct of the pneumatic linear conveyor through holes or slots.

[0024] The object of the invention is also a method for producing tobacco industry rods, the method comprising the steps of: feeding at least one filling material for the continuous rod using at least one feeding unit, delivering at least one wrapping material for wrapping the filling material using a delivery unit, applying glue to the wrapping material or to the filling material for the continuous rod using a glue applicator, forming the continuous rod from the wrapping material and filling material in the forming unit, and cutting the continuous rod into rods of a specified length using a cutting head. The method further comprises pneumatically extracting the continuous rod from the forming unit by means of a pneumatic linear conveyor located between the forming unit and the cutting head.

[0025] The method may comprise extracting the continuous rod in a contactless manner.

[0026] The method may comprise extracting the continuous rod by means of pressure applied to a pneumatic linear conveyor.

[0027] The method may comprise applying pressure in the range from 2 to 6 bar.

[0028] BRIEF DESCRIPTION OF DRAWINGS

[0029] The object of the invention is shown by means of preferred embodiments in the drawings, wherein:

[0030] Fig. 1 shows a machine for manufacturing multi-segment rods with a device for pneumatic extraction of a continuous rod,

[0031] Fig. 2 shows a machine for manufacturing continuous filter fiber rods with a device for pneumatic extraction of a continuous rod,

[0032] Fig. 3 shows a device for pneumatically extracting a continuous rod from a forming unit in cross-sectional view,

[0033] Fig. 4 shows a device for pneumatically extracting a continuous rod from a forming unit, depicted in an enlarged cross-sectional view,

[0034] Fig. 5 shows a device for pneumatically extracting a continuous rod from a forming unit, shown in an A-A cross-sectional view with holes,

[0035] Fig. 6 shows a device for pneumatically extracting a continuous rod from a forming unit, displayed in an A-A cross-sectional view with a slot.

[0036] DETAILED DESCRIPTION

[0037] Fig. 1 shows a machine 1 for manufacturing a tobacco industry multi-segment rod R. In this embodiment, the filling material is formed by segments 14, which are fed from feeding units 3 onto a receiving belt 4, which transports the assembled train of segments 14 to a transfer unit 5. From the transfer unit 5, the segments are received onto a strand of wrapping material 6, supplied from a delivery unit 7, and moved together with the segments toward a forming unit 8. A glue path is then applied to the wrapping material 6 using a glue applicator 9, and the wrapping material 6 is wrapped around the train of segments 14 in the forming unit 8 to form a continuous rod CR. From the forming unit 8, the continuous rod CR is pneumatically extracted by a pneumatic linear conveyor 10 and transported in a contactless manner toward a cutting head 11 , wherein it is cut into rods R.

[0038] Fig. 2 shows a machine 2 for manufacturing rods R from a continuous filtering fiber 12. The machine 2 is provided with the feeding unit 3 for supplying the filling material for the continuous rod CR, in this embodiment, it is the continuous filtering fiber 12. After suitable processing, such as the addition of a flavor or fragrance, the filtering fiber 12 is moved to a forming funnel 13, from which it then passes to the forming unit 8 along with the wrapping material 6 supplied from the delivery unit 7. In the forming unit 8, the wrapping material 6 is wrapped around the filtering fiber 12 and bonded with the glue previously supplied from the glue applicator 9. The continuous rod CR thus formed is pneumatically extracted in a contactless manner from the forming unit 8 by the pneumatic linear conveyor 10 and moved in a contactless manner toward the cutting head 11 , where it is cut into rods R. By “contactless” extraction, it is meant that there is no contact between the continuous rod CR and the component used for its extraction, namely the pneumatic linear conveyor 10.

[0039] Fig. 3 shows a pneumatic linear conveyor 10 for pneumatically extracting a continuous rod CR, shown in cross-sectional view, with a portion of the forming unit 8, and the cutting head 11 visible. A train of segments 14 arranged in a suitable configuration is introduced into the forming unit 8 by a garniture belt 15, which, after wrapping with the wrapping material 6, forms a continuous rod CR.

[0040] In conventional machines, the formed continuous rod CR is propelled through the forming unit 8, specifically with the assistance of the garniture belt 15, towards the cutting head 11. If an increased frictional resistance occurs between the propelled continuous rod CR and the duct 16 of the forming unit 8, the continuous rod CR may become jammed in the duct 16, leading to a machine stoppage and necessity to clean the duct 16 by the operator. Other potential damage to the continuous rod CR includes an not-completely bonded glue seam, which, after the continuous rod CR exits the duct 16 unsupported, may result in a breakage of the continuous rod CR and subsequent machine stoppage. Although various devices in the prior art support the rod after it exits the forming unit 8 or extract it from the duct 16, none of them addresses the issue of supporting the continuous rod CR and extracting it from the forming unit 8 in a contactless manner, which significantly impacts the quality of the produced continuous rod CR.

[0041] In the present solution, the formed continuous rod CR, upon exiting the duct 16 of the forming unit 8, disengages from the garniture belt 15 and is introduced into the inlet

[0042] 17 of the duct 18 of the pneumatic linear conveyor 10. The pneumatic linear conveyor 10 is positioned between the forming unit 8 and the cutting head 11 , ensuring that the outlet 19 of the duct 18 of the pneumatic linear conveyor 10 is as close as possible to the cutting head 11. This configuration guarantees that the continuous rod CR is supported along an extended displacement path in a contactless manner, preventing the continuous rod CR, as it is displaced, from breaking, even if it has a defect or an unbonded glue seam. The contactless support of the continuous rod CR is achieved by an air bearing, which forms around the moving continuous rod CR once a compressed gas, such as air P, is supplied to the pneumatic linear conveyor 10. The unsupported distance traversed by the continuous rod CR equals the distance from the outlet 19 of the duct 18 to the sleeve 20, which subsequently supports the continuous rod CR during its cutting by the cutting head 11. Given that the sleeves 20 execute either a circular or elliptical motion, and depending on the design of the drive, may perform a motion coinciding with that of the continuous rod CR, it simplifies the determination of the distance from the outlet 19 of the duct 18 to the knife 22 of the cutting head 11. This distance ranges from 5 to 150 mm, preferably from 5 to 100 mm.

[0043] Compressed gas P, supplied from its supply (not shown in the drawing) to the pneumatic linear conveyor 10, flows through channels 21 , then through holes 23, which distribute it circumferentially around the continuous rod CR exiting into channel

[0044] 18 through radially spaced holes 23. It is then directed in the T direction of movement of the continuous rod CR along its X axis, as depicted in Fig. 4. The holes 23 can guide the compressed gas P out of the duct 21 into the chamber 25 of the duct 18, shaped into a cone at this section as shown in Fig. 4, or directly into the duct 18 with cylindrical walls as seen in the remaining section of the duct 18. It is important that the compressed gas P exiting the openings 23 is at least partially oriented toward the outlet 19 of the duct 18. The compressed gas P can be fed into the duct 18 inside the pneumatic linear conveyor 10 circumferentially through several openings 23 arranged circumferentially around the duct 18 or through an annular slot 24 aligned with the longitudinal axis of the duct 18, as shown respectively in Fig. 5 and Fig. 6. The corresponding pressure value and method of supplying the compressed gas P results in an air bearing being formed inside the duct 18 around the continuous rod CR, which supports the continuous rod CR and exerts a force F essentially coinciding with the direction of displacement T. The pressure value of the gas supply P to the pneumatic linear conveyor 10 should range from 1 to 7, preferably from 2 to 6 bar.

[0045] As the continuous rod CR is subjected to the force F exerted by the compressed gas P and the structure of the pneumatic linear conveyor 10, the effect of extracting the continuous rod CR out of the forming unit 8 is achieved. The force F generated by the pneumatic linear conveyor 10 maintains the appropriate tension of the continuous rod CR with the wrapping material 6, preventing the wrapping material 6 from undergoing transverse deformation. The force F should be high enough to overcome all the resistances present in the forming unit 8 and enable the extraction of the continuous rod CR. However, the force F should not be excessively high to avoid damaging the continuous rod CR. The value of the force F applied to the continuous rod should range from 1 to 80 N, preferably from 2 to 70 N.

[0046] By applying a pneumatic linear conveyor 10 on a machine 1 , 2 for producing tobacco industry rods R in the cutting head area 11 immediately after the outlet of the forming unit 8, the blocking of the continuous rod CR in the forming unit 8 can be eliminated, and the breaking of the continuous rod CR after exiting the forming unit can be prevented by supporting it in a contactless manner. This reduces the frequency and duration of machine stoppages, leading to enhanced productivity.

[0047] REFERENCE SIGNS

[0048] 1 machine for producing multi-segment rods,

[0049] 2 machine for producing rods from continuous filter fiber,

[0050] 3 feeding unit of filling material

[0051] 4 receiving belt

[0052] 5 transfer unit

[0053] 6 wrapping material

[0054] 7 wrapping material delivery unit

[0055] 8 forming unit

[0056] 9 glue applicator 10 pneumatic linear conveyor

[0057] 11 cutting head

[0058] 12 continuous filter fiber

[0059] 13 forming funnel

[0060] 14 train of segments

[0061] 15 garniture belt

[0062] 16 forming unit duct

[0063] 17 inlet of duct of pneumatic linear conveyor

[0064] 18 duct of pneumatic linear conveyor

[0065] 19 outlet of duct of pneumatic linear conveyor

[0066] 20 support sleeve

[0067] 21 compressed gas supply ducts

[0068] 22 cutting head knife

[0069] 23 holes

[0070] 24 slot

[0071] 25 duct chamber

[0072] R tobacco industry rod

[0073] CR continuous rod

[0074] T direction of movement of continuous rod

[0075] P compressed gas

[0076] F force acting on continuous rod

[0077] X longitudinal axis of continuous rod

Claims

CLAIMS1. A machine (1 , 2) for producing tobacco industry rods (R), the machine comprising:- at least one feeding unit (3) for supplying filling material (12, 14) for the continuous rod (CR),- at least one delivery unit (7) for providing a strand of wrapping material (6) for wrapping the filling material of the continuous rod (CR),- at least one glue applicator (9) for applying glue to the wrapping material (6) or to the filling material (12, 14) for the continuous rod (CR),- a forming unit (8) for forming the continuous rod (CR) from the wrapping material (6) and the filling material (12, 14), and- a cutting head (11 ) for cutting the continuous rod (CR) into rods (R) of a specified length, characterized in that the machine further comprises a pneumatic linear conveyor (10) for pneumatically extracting the continuous rod (CR) from the forming unit (8), located between the forming unit (8) and the cutting head (11 ).

2. The machine according to claim 1 , wherein the pneumatic linear conveyor (10) has a body with an elongated duct (18) for guiding the continuous rod (CR), the duct (18) has an inlet (17) located at the outlet of the forming unit (8) and an outlet (19) located at the cutting head (11 ), and the duct (18) has a supply of compressed gas (P) forming an air bearing around the continuous rod (CR).

3. The machine according to any of claims 1 to 2, wherein the diameter of the duct (18) of the pneumatic linear conveyor (10) is 15 to 60% larger than the diameter of the continuous rod (CR).

4. The machine according to any of claims 1 to 3, wherein the pneumatic linear conveyor (10) generates a force (F) acting on the continuous rod (CR) axially longitudinally in the direction (T) of the cutting head (11 ).

5. The machine according to any of claims 1 to 4, wherein the pneumatic linear conveyor (10) extracts the continuous rod (CR) in a contactless manner.

6. The machine according to any of claims 1 to 5, wherein the pneumatic linear conveyor (10) supports the continuous rod (CR) in a contactless manner.

7. The machine according to any of claims 1 to 6, wherein the pneumatic linear conveyor (10) generates a force (F) in the range from 1 N to 70N.

8. The machine according to any of claims 1 to 7, wherein a compressed gas (P) is supplied to the pneumatic linear conveyor (10) under pressure of 2 to 6 bar.

9. The machine according to any of claims from 1 to 8, wherein the outlet (19) of the duct (18) of the pneumatic linear conveyor (10) is positioned at a distance in the range from 5mm to 100mm from the knife (22) of the cutting head (11 ).

10. The machine according to any of claims 1 to 9, wherein the compressed gas (P) is let into the duct (18) of the pneumatic linear conveyor circumferentially in relation to the longitudinal axis of the duct (18).

11. The machine according to any of claims 1 to 10, wherein the compressed gas (P) is let into the duct (18) of the pneumatic linear conveyor through holes (23) or slots (24).

12. A method for producing tobacco industry rods (R), the method comprising the steps of:- feeding at least one filling material (12, 14) for the continuous rod (CR) using at least one feeding unit (3),- delivering at least one wrapping material (6) for wrapping the filling material (12, 14) using a delivery unit (7),- applying glue to the wrapping material (6) or to the filling material (12, 14) for the continuous rod (CR) using a glue applicator (9),- forming the continuous rod (CR) from the wrapping material (6) and filling material (12, 14) in the forming unit (8), and- cutting the continuous rod (CR) into rods (R) of a specified length using a cutting head (11 ),characterized by further comprising pneumatically extracting the continuous rod (CR) from the forming unit (8) by means of a pneumatic linear conveyor (10) located between the forming unit (8) and the cutting head (11 ).

13. The method according to claim 12, comprising extracting the continuous rod(CR) in a contactless manner.

14. The method according to one of claims 12 to 13, comprising extracting the continuous rod (CR) by means of pressure applied to a pneumatic linear conveyor (10).

15. The method according to claim 14, comprising applying pressure in the range from 2 to 6 bar.

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