Unwinding a film roll in a packaging machine

Abstract

A packaging machine which unwinds a bottom film web from a supply roll and conveys it intermittently or continuously along the packaging machine and in a forming station, forms into the bottom film web packaging cavities, which are then filled with a product to be packaged. In a sealing station, a top film web is sealed to the bottom film web, wherein the bottom and top film web are respectively unwound from a supply roll and the bottom and top film web are respectively tensioned by means of a dancer roll. The supply roll is driven by means of a motor, the parameters of which, in particular rotation speed and/or torque, can be set on the basis of the parameters of the respective supply roll.

Claims

1. A packaging machine which unwinds a bottom film web from a first supply roll and conveys the bottom film web intermittently or continuously along the packaging machine, wherein the packaging machine comprises a forming station that forms the bottom film web into packaging cavities, which are then filled with a product to be packaged, wherein the packaging machine comprises a sealing station and subsequently, in the sealing station, a top film web is sealed to the bottom film web, wherein the top film web is unwound from a second supply roll, and the bottom film web and the top film web are respectively tensioned by means of a dancer roll, wherein the first supply roll and/or the second supply roll is driven by means of a motor, and parameters of the motor which, include rotation speed and/or torque, can be set on a basis of parameters of the first supply roll and/or the second supply roll.

2. The packaging machine as claimed in claim 1, wherein the motor is a torque motor.

3. The packaging machine as claimed in claim 1, wherein the dancer roll has a movement transducer that is a rotary encoder, and a signal of the movement transducer is used to regulate and/or control the motor.

4. A packaging machine which unwinds a bottom film web from a first supply roll and conveys the bottom film well intermittently or continuously along the packaging machine, the packaging machine comprises a forming station that forms the bottom film web into packaging cavities, which are then filled with a product to be packaged, wherein the packaging machine comprises a sealing station and subsequently, in the sealing station, a top film web is sealed to the bottom film web, wherein the top film web is unwound from a second supply roll, and the first supply roll and/or the second supply roll is rotatably mounted on a shaft, wherein, as a result of the rotation, the bottom film web and/or the top film web is unwound in a running direction, wherein the shaft is displaceable along a longitudinal center axis of the shaft.

5. A method for producing a packaging with a packaging machine which unwinds a bottom film web from a supply roll and conveys the bottom film web intermittently or continuously along the packaging machine, the packaging machine comprises a forming station that forms the bottom film web into packaging cavities, which are then filled with a product to be packaged, wherein subsequently, in a sealing station, a top film web is sealed to the bottom film web, wherein the top film web is unwound from a second supply roll and the bottom film web and top film web are respectively tensioned by means of a dancer roll, wherein the supply roll is unwound, driven by means of a motor.

6. The method as claimed in claim 5, wherein the second supply roll is unwound, at least substantially, in accordance with a feed rate of the bottom film web.

7. The method as claimed in claim 5, wherein parameters of the motor, that include rotation speed and torque, are set on a basis of the parameters of the second supply roll, in particular a diameter and weight of the second supply roll.

8. The method as claimed in claim 5, wherein at least when the film web is changed, the diameter and/or the weight of the second supply roll are determined.

9. The method as claimed in claim 5, wherein at least during automatic unwinding of the supply roll, a deviation of an actual position from a target position of the dancer roll is registered and, from this, a correction value to a previously calculated unwinding speed/torque is determined and taken into account.

10. The method as claimed in claim 5, wherein the dancer roll has a movement transducer, that is a rotary encoder, and a signal of the movement transducer is used to regulate and/or control the motor.

11. The method as claimed in claim 5, wherein a nominal width of the bottom film web and the top film web is inputted or read out automatically.

12. The method as claimed in claim 5, wherein the supply roll parameters are drawn from a database and/or a data carrier.

13. The method as claimed in claim 5, wherein, on a basis of the parameters of the supply roll and/or a registered unwinding history, the residual length of the film web is determined.

14. A method, in which a bottom film web unwinds from a first supply roll and is conveyed intermittently or continuously along a packaging machine and in a forming station is formed into packaging cavities, which are then filled with a product to be packaged, wherein subsequently, in a sealing station a top film web is sealed to the bottom film web, wherein the top film web is unwound from a second supply roll, and the first supply roll and/or the second supply roll are rotatably mounted on a shaft, wherein, as a result of the rotation, the bottom film web and/or the top film web is unwound in a running direction wherein the shaft comprises a longitudinal center axis and the shaft is displaced along the longitudinal center axis.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The inventions are explained in greater detail below with reference to FIGS. 1 to 4. These statements are merely exemplary and do not limit the general inventive concept. The statements apply equally to all subjects of the present invention.

[0041] FIG. 1 shows the packaging machine according to the invention.

[0042] FIG. 2 shows a supply roll drive with a toothed belt.

[0043] FIG. 3 shows a torque motor.

[0044] FIG. 4 shows the film unwinding facility of a packaging machine.

DETAILED DESCRIPTION

[0045] FIG. 1 shows the packaging machine 1 according to the invention, which has a deep-drawing station 2, a filling station 7 and a sealing station 15. A bottom film web 8, here a plastics film web 8, is drawn off from a supply roll 22 and conveyed in cycles along the packaging machine according to the invention from right to left. In the course of a cycle, the bottom film web 8 is advanced by a format length/feed length. For this, the packaging machine has two conveying means (not represented), in the present case respectively two endless chains, which are arranged to the right and left of the bottom film web 8. Both at the start and at the end of the packaging machine, for each chain there is respectively provided at least one gearwheel, around which the respective chain is deflected. At least one of these gearwheels is driven. The gearwheels in the entry region and/or in the exit region can be connected to one another, preferably by a rigid shaft. Each conveying means has a multiplicity of clamping means, which clampingly grip the bottom film web 8 in the inlet region 19 and transmit the movement of the conveying means to the bottom film web 8. In the outlet region of the packaging machine, the clamping connection between the conveying means and the bottom film web 8 is released again. Downstream of the inlet region 19 is provided a heating means 13, which warms the film web 8, in particular when this is stationary. In the deep-drawing station 2, which possesses a top tool 3 and a bottom tool 4, which has the shape of the packaging cavity which is to be produced, the packaging cavities 6 are formed into the warmed film web 8. The bottom tool 4 is arranged on a lifting table 5, which, as is symbolized by the double arrow, is vertically adjustable. Prior to each film feed, the bottom tool 4 is lowered, and afterward raised again. In the further course of the packaging machine, the packaging cavities are then in the filling station 7 filled with the product to be packaged 16. In the following sealing station 15, which likewise consists of a top tool 12 and a vertically adjustable bottom tool 11, a top film 14 is integrally fastened to the bottom film web 8 by sealing. The movement of the bottom film web 8 is thereby transmitted to the top film web 14. In the sealing station too, the top tool and/or the bottom tool, before and after each film transport, is lowered or raised. The top film 14 too can be guided in conveying means or conveyed by conveyor chains, wherein these conveying means then extend only before the sealing station and, where appropriate, downstream. Otherwise, the comments which were made regarding the conveying means of the bottom film apply. The top film too can be warmed with a heating means and deep-drawn. For the sealing, there is provided as the bottom tool 11, for instance, a heatable sealing frame, which, for each packaging cavity, has an opening into which the packaging cavity, in the course of the sealing, i.e. upon the upward movement of the bottom sealing tool, intrudes. For the sealing, the top and bottom film web are pressed together between the top and bottom tool 12, 11 and are joined under the influence of heat and pressure. After the sealing, the tools 11, 12 are moved apart again vertically. Between the supply roll 21 and the sealing tool is provided a dancer roll 20, here a rotational dancer roll, keeps the film web 14 as far as possible at a constant tension. The person skilled in the art will understand that a plurality of top films can be present, for instance in the case of a multilayer packing or a packing having a plurality of top films. Preferably, in the course of each top film, a dancer roll is then provided. The person skilled in the art will further understand that, also in the region of the bottom film, a dancer roll is preferably provided, preferably downstream of the supply roll 22. Preferably, the dancer roll is constituted by a linear dancer roll. Before and/or during the sealing of the top film to the bottom film, in each packaging cavity a gas exchange is preferably made. For this, the air present in the packaging cavity is firstly partially extracted and then replaced by an exchange gas. For this, in the region of each format holes are made in the bottom film, while in the region of the conveyor chains holes are made in the bottom film web, through which holes the air between the film webs 8, 14 is extracted and the exchange gas is then blown in. In the further course of the packaging machine, the finished packagings are separated, which in the present case is realized with the transverse cutter 18 and the longitudinal cutter 17. The transverse cutter 18 can in the present case likewise be raised or lowered with a lifting device 9.

[0046] According to the invention, at least one supply roll 21, 22 is driven by a motor, in particular a torque motor, such that the length of the respectively required feed of the respective film web is unwound from the roll without the tensile force of the two conveying means, of the conveyor chains, and/or the tensile force of the bottom film web, being significantly transmitted to the top film web. As a result, the respective film web is subjected only to a comparatively small tension and thus is not prestretched and does not crease. With the packaging machine according to the invention or with the method according to the invention, also comparatively thin film webs can be processed. No film brake for the top film web is required in order to adapt the position of the print marks on the top film to the position of the cavities in the bottom film web. The dancer roll must be designed only for very small movements or for a very small, or even no, film web storage volume.

[0047] Preferably, the rotation of the motor which drives the supply roll 21, 22 is controlled/regulated by a computer means, which can be part of the packaging machine or part of a linear control system. In particular, the rotation speed of the supply roll is controlled such that the unwound film web length corresponds to the feed, and/or such that the speed profile of the unwinding of the film web and/or of the feed of the conveying means, in particular of the conveyor chains, is at least substantially identical. The respectively current diameter or the respectively current weight of the supply roll is here taken into account.

[0048] Preferably, the dancer roll is provided with a movement transducer, for instance a rotary encoder or a linear, with which can be determined the stored film length to which the movement of the dancer roll corresponds. This information can be used, for instance, to determine the diameter of the supply roll.

[0049] Preferably, a dancer roll is provided in the region of the bottom and of the top film web. Preferably, the supply roll of the bottom film web and/or of the top film web is driven with a motor such that the unwinding of the respective film web is realized with a motor drive such that the respective film web is at most only slightly tensioned.

[0050] FIG. 2 shows a first embodiment of the drive for unwinding the supply roll 21, 22. In the present case, between the motor 25, here preferably a torque motor, is connected by means of a toothed belt to the drive shaft 23 of the supply roll. The supply roll is in turn connected in a rotationally secure manner to the drive shaft 23. By this rotary drive, the rotary movement of the motor is transmitted without slippage to the shaft on which the supply roll is mounted.

[0051] FIG. 3 shows a so-called direct drive, in which the power take-off shaft of the motor is directly connected to the rotary shaft of the supply shaft. The motor is constituted by a torque motor.

[0052] FIG. 4 shows a further embodiment of the packaging machine according to the invention, wherein reference can substantially be made to the comments according to FIG. 1. The supply roll 21, 22 is mounted on a shaft 23, preferably such that it is rotationally secure and/or non-axially displaceable. In the unwinding of the bottom and/or top film web 8, 14, the shaft 23 rotates in the direction indicated by the arrow 40. The shaft 23 is preferably supported in the region of its two ends, in a rotatable and, where appropriate, also longitudinal manner, by means of a bearing 31. A bearing 31 can be provided, for instance, on the housing of the film unwinding facility or of the packaging machine. For a longitudinal displacement, the bearings 31 can be realized as slide bearings. The shaft 23 is preferably rotationally driven by means of a motor 25. Between the motor 25 and the shaft 23, a coupling 26, for instance a sliding coupling or a gear, preferably a sliding gear, can be provided. According to the invention, the shaft 23 alone, and/or the frame 29 on which the shaft 23 of the film unwinding facility is mounted, is now provided such that it is longitudinally displaceable, as symbolized by the arrow 37, and/or transversely to the direction of transport 40 of the film web. For this, the frame 29, on which the shaft 23 and the motor 25 are provided, is provided, for instance, such that, it is longitudinally displaceable, for instance along a guide 32. The movement 37 is effected, for instance, by an adjustment drive 35, which moves at least the shaft 23 along its center axis, preferably, however, also the frame 29. The person skilled in the art will understand that also the drive motor 25, in the longitudinal displacement, can, but does not have to be, jointly moved. The mounting 32-34 is preferably arranged on an, in particular fixed, base frame 28.

[0053] Preferably, the packaging machine according to the invention has a sensor 39, which is preferably a web edge detection means. This web edge detection means 39 detects the position of the web edge, for instance relative to the frame of the packaging machine or to some other, preferably fixed, location. Should the web edge be located beyond a desired limit, the adjustment drive 35 is preferably activated, which then moves the shaft 23 or the frame 29 in the direction symbolized by the arrows 37 to the point where the film web is again within the desired limit.

REFERENCE SYMBOL LIST

[0054] 1 packaging machine

[0055] 2 forming station, deep-drawing station

[0056] 3 top tool of the deep-drawing station

[0057] 4 bottom tool of the deep-drawing station

[0058] 5 lifting table, carrier of a tool of the sealing, deep-drawing station and/or of the cutting device

[0059] 6 packaging cavity

[0060] 7 first filling station

[0061] 8 film web, bottom film web, material web

[0062] 9 lifting device

[0063] 10 drive

[0064] 11 bottom tool of the sealing station

[0065] 12 top tool of the sealing station

[0066] 13 heating means

[0067] 14 top film web, cover film, material web

[0068] 15 sealing station

[0069] 16 product to be packaged

[0070] 17 longitudinal cutter

[0071] 18 transverse cutter

[0072] 19 inlet region

[0073] 20 dancer roll

[0074] 21 supply roll of the top film web

[0075] 22 supply roll of the bottom film web

[0076] 23 shaft of the supply roll

[0077] 24 drive means, toothed belt

[0078] 25 motor, torque motor

[0079] 26 coupling, sliding coupling

[0080] 27 motor shaft

[0081] 28 base frame, packaging machine

[0082] 29 support, displaceable frame

[0083] 30 door, bearing housing, frame

[0084] 31 bearing, slide bearings

[0085] 32 guide, guide rod

[0086] 33 bearing, slide bearings

[0087] 34 bearing pedestal, bearing housing

[0088] 35 adjustment drive, motor, gear motor, spindle motor, servo motor

[0089] 36 spindle, shaft, adjusting means, sliding means

[0090] 37 adjustment direction, sliding direction

[0091] 38 web edge, film edge, material web edge

[0092] 39 sensor, web edge detection means

[0093] 40 direction of transport, film running direction, web running direction