EP1714874A1 - Method of unwinding web material in a packaging machine and a packaging machine - Google Patents

Abstract

The method involves unwinding a preset length of a web material from a supply roller, accommodating in a storage unit (2) and removing processed material from a storage unit (4) when a work station is operating. The units are arranged before and behind the station, respectively. The material is supplied from the unit (2) to the station, removed from the station and accommodated in the unit (4) when the station is not operating. An independent claim is also included for a packing machine, which is formed for synchronized intermittent transport of web material.

Description

The present invention relates to a method of unrolling web material in a batch intermittent packaging machine and to a packaging machine.

There are known packaging machines, which are formed as shown schematically in Fig. 5 and in which web material 6, such as a plastic film or a thin metal foil is unrolled from a supply roll 1 and then a workstation 3 is supplied. As workstations, for example, sealing stations in which the web material 6 is thermally sealed with other components, or cutting stations are known in which parts of the web material 6, for example, are cut out by means of a punch. It is also known that such work stations 3 are formed as combined sealing and cutting stations in which the web material 6 is sealed onto containers 8 and subsequently the sealed areas are cut out of the web material. In these packaging machines remains after the workstation 3, a lattice-shaped frame 6 'of the web material, which has a low stability and must be removed again. The removal is usually carried out to a pickup roller 5, on which the frame-shaped residual web material 6 'is rolled up so that it can be disposed of or recycled.

In the packaging machine shown in Fig. 5, containers 8 are fed via a feed conveyor belt 9 to the sealing and cutting station 3 and sealed therein with the top film 6 and then cut free. After the work station 3, the sealed containers 8 'are transported on with a conveyor belt 12.

Such packaging machines operate in a cyclic intermittent manner, in one step with the active (closed) workstation, the processing of the web material and in another step with inactive (open) workstation feeding the web material to be processed from the supply roll to the workstation and the Discharge of processed web material is done from the workstation.

In the known packaging machines, the workstation stands still for a long time in the inactive open state, since the unrolling of the web material from the supply roll must on the one hand be carried out very carefully, since as web material e.g. Plastic films are only 25 microns thick, and on the other hand weighs the supply roll up to 100 kg, so that large mass accelerations are required for rolling. Even when rolling up the processed web material, large mass accelerations are required.

Effective utilization of a workstation requires that it be available for at least 75-90% of the time for its actual tasks and that it is inactive for only 10 to a maximum of 25% of the time. The standstill of the workstation in the inactive state due to the web transport means that during this time no processing can take place, so that the processing speed is limited by the supply of the web material.

Further, in the known packaging machines, the problem arises that the required mass accelerations are not constant over the duration of processing many packages, but the mass of the supply roll decreases due to the rolling and increases the mass of the discharge roller due to the rolling up of the residual material. Thus, it is difficult to control the process in the packaging machine such that the web material is quickly transported to the workstation and out of the workstation and the web material is kept taut and not subjected to such severe stresses that cause the web material to rupture. In the case of the web material to be removed, the additional problem arises that, owing to the frame or lattice structure, the latter is easily imposed on components of the machine or also tears more easily than the starting material.

It is known to realize the feed of web material with transport chains, which grip the web material laterally and move along a distance. Such transport chains, however, do not make it possible to use different web widths without costly retooling measures.

From the DE 195 35 535 A1 a packaging machine is known which operates intermittently in cycles and has a printer for printing a film web, as well as several workstations such as a sealing station. In the apparatus incorporating the printer, two rollers form a linear accumulator located in front of and behind the printer for further advancing a portion of the film web in the printing device incrementally at a faster rate during standstill of the film web outside the printer device in a main press cycle. In the packaging machine disclosed, the film web is unrolled from a supply roll when the printer is inactive, ie not working, and when the sealing station is not operating in the main machine cycle. The workstations stand still for the duration of the unrolling of the film web.

In the GB 1 089 792 there is disclosed a packaging machine in which a linear memory for receiving a portion of a web material is provided in front of and behind a marking or punching station, respectively, which is intermittently operated, the two memories being coupled together. In the packaging machine disclosed, a continuous movement of the web material in front of the work station is converted to a clocked movement and returned to a continuous one after the workstation. The packaging machine, however, has the disadvantage that adjusting the length of a web section to be transported further in one cycle can only take place via the transport speed of the continuous web feed and removal, and the working speed of the workstation, which also have to be coordinated. Furthermore, this document also does not show the rolling of web material from a supply or feed roll.

From the US 4,753,059 a packaging machine is known in which two linear storage are used in front of and behind a pressure roller. These are controlled in such a way that a movement of a film web through the printing device at a constant speed takes place in order to achieve a good pressure. In the packaging machine, there is the disadvantage that the rolling of web material from a supply roll must be done carefully with non-working workstation.

It is an object of the present invention to provide a method and a packaging machine, which reduce the inactive operating times of a workstation and thus are faster, but still ensure a safe rolling of web material for different web widths.

The object is achieved by a method according to claim 1.

The object is also achieved by a packaging machine according to claim 9.

Further developments of the invention are each characterized in the subclaims.

With the method and apparatus according to the invention, the unrolling of the web material from the feed roll and the rolling up of processed web material are decoupled from the web transport into and out of a work station. This allows web transport into and out of the workstation to be done very quickly since no large mass accelerations are required to move the web material from the first memory into the workstation and out of the workstation into the first memory. The time-consuming unrolling of web material and reeling of processed web material requiring high mass accelerations occurs during the time the workstation is closed and operating.

Furthermore, it is possible that the supply of material to be processed web material to the workstation and the removal of processed web material from the workstation are easily coupled together and thus the web tension during this fast transport can be kept substantially constant.

Further, according to the present invention, easy conversion to various web widths is ensured, and the unrolling of the web material to be processed from the supply roll and the reeling of the processed web material onto the discharge reel may take place separately from each other during the time when the work station is closed. This can also be done in easy way, the decreasing mass of the supply roll and the increasing mass of the discharge roller are considered in the rolling and rolling.

Fig. 1

eine schematische perspektivische Darstellung einer Verpackungsmaschine mit geschlossener Arbeitsstation und gefüllter erster Speichereinrichtung und leerer zweiter Speichereinrichtung;

Fig. 2

eine schematische perspektivische Darstellung des Bahntransports aus der ersten Speichereinrichtung in die Arbeitsstation und aus der Arbeitsstation in die zweite Speichereinrichtung bei geöffneter Arbeitsstation;

Fig. 3

eine schematische perspektivische Darstellung der Verpackungsmaschine unmittelbar nach dem Schließen der Arbeitsstation;

Fig. 4

eine schematische perspektivische Darstellung des Abrollens von zu bearbeitendem Bahnmaterial in die erste Speichereinrichtung und des Abführens von bearbeitetem Bahnmaterial aus der zweiten Speichereinrichtung; und

Fig. 5

eine schematische perspektivische Darstellung einer Verpackungsmaschine, in der zugeführte Behälter mit einer Folie versiegelt werden.

Further features and advantages of the invention will become apparent from the description of embodiments with reference to the accompanying drawings. From the figures show:

Fig. 1

a schematic perspective view of a packaging machine with a closed workstation and filled first storage device and empty second storage device;

Fig. 2

a schematic perspective view of the web transport from the first storage device into the workstation and from the workstation to the second storage device with open workstation;

Fig. 3

a schematic perspective view of the packaging machine immediately after closing the workstation;

Fig. 4

a schematic perspective view of the rolling of web material to be processed in the first storage device and the discharge of processed web material from the second storage device; and

Fig. 5

a schematic perspective view of a packaging machine, in the supplied Container to be sealed with a foil.

An embodiment of the present invention will be described below with reference to Figs.

As shown in Fig. 1, in this embodiment, the packaging machine has a supply roll 1 for web material 6 to be processed, a first storage device 2, a workstation 3, a second storage device 4, and a processed web discharge device 6 ' , In the embodiment illustrated in FIGS. 1 to 4, the work station 3 is a cutting station in which 6 areas are cut out of the web material to be processed, so that the processed web material 6 'is a frame-like or lattice-like web material. The sheet material 6 to be processed is e.g. around a thin plastic film.

On the supply roll 1, a large amount of the sheet material 6 to be processed is provided in a rolled form as a supply, and the discharge device 5 is also formed as a roll on which the processed sheet material 6 'is rolled up.

The first storage device is formed by three rollers arranged parallel to one another, wherein two rollers 20 and 21 are fixedly attached to a machine frame and a variable roller 22 is displaceably arranged in the vertical direction. The web material 6 to be processed extends from the feed roller 1 over the first stationary roller 20, forming a loop over the variable roller 22 and then over the second stationary roller 21. After the second stationary roller 21, the web material 6 to be processed continues to run over one On the input side of the workstation 3 arranged stationary deflection roller 30 to the workstation 3. The processed web material 6 'extends from the workstation 3 via a fixed deflection roller 31 arranged on the output side of the workstation 3 to the second storage device 4.

The second storage device 4 is similar to the first storage device 3 formed by three parallel rollers, wherein two rollers 40 and 41 are fixedly fixed to a machine frame and a variable roller 42 is provided in the vertical direction slidably below the two stationary rollers 40 and 41. The processed web material 6 'extends from the stationary roller 31 of the work station 3 via the stationary roller 40, forming a loop over the variable roller 42 and then on the stationary roller 41. From the stationary roller 41, the processed web material 6' extends to the Discharge device 5.

The variable roller 22 of the first storage device 2 and the variable roller 42 of the second storage device 4 are mechanically coupled to one another via a chain strand 7 fastened to the machine frame. The chain strand 7 extends in the embodiment shown in FIGS. 1 to 4 via four deflection rollers 70, 70a, of which the deflection roller 70a can be set in rotation by means of a drive 71. The variable roller 22 and the variable roller 42 are fixed to the chain strand 7 and guided in a rear wall of the machine frame in elongated recesses 23 and 43, respectively.

With this coupling, as shown in Fig. 2, with a movement of the chain strand 7 in the clockwise direction, the variable roller 42 of the second memory device 4 downwardly moved away from the stationary rollers 40 and 41 and thus located in the second memory device 4 loop of machined web material 6 'enlarged. At the same time, in this clockwise movement, the variable roller 22 of the first storage device 2 becomes vertical toward the fixed ones Rolls 20 and 21 to move and thus reduces the loop formed in the first memory device 2 of web material 6 to be processed. The loop in the first storage device 2 is thereby reduced in size to the same extent in which the loop in the second storage device 4 is enlarged.

Conversely, as can be seen in Fig. 4, as the chain strand 7 moves counterclockwise, the loop in the second storage device 4 is reduced in size by moving the variable roller 42 upwards and, at the same time, the loop in the first storage device to the same extent move down the variable roller 22 increases.

It is further shown in FIGS. 1 to 4 that the feed roller 1 is provided with a drive 10 which can set it in rotation, and the discharge device 5 is provided with a drive 50 which can set it in rotation.

On the input side of the workstation 3, a brake not shown in the drawings is further provided, which can prevent movement of web material 6 in the workstation.

The work station 3 is either in an open state shown in Fig. 2 or non-working state, in which no processing of the web material takes place, or in a in Figs. 1, 3 and 4 illustrated closed state or working state in which a Processing of the web material takes place.

With reference to Figs. 1 to 4, the operation of the illustrated embodiment will be described below.

In FIG. 1, the work station 3 is in a working state and is located in the first storage device 2 the variable roller 22 in a lower end position, which can be preset via an adjustment device not shown in the drawing, so that a loop is formed to be processed web material 6, in which a certain length of the web material 6 is stored. In the second storage device 4, the variable roller 42 is in an upper end position, so that the loop of the processed web material 6 'in the second storage device 4 has a minimum length. The feed roller 1 and the discharge device 5 are both at rest.

In a step shown in Fig. 2, the workstation 3 is finished with the processing of the web material 6 and is already in a non-working state. Immediately after opening the work station 3, the drive 71 is driven so that the chain strand 7 is moved over a predetermined distance in a clockwise direction, as shown by the arrow 72. By the movement of the chain strand 7, the variable roller 22 in the first storage device is moved upward along the arrow 24, so that the loop stored in the first storage device 2 is reduced, and at the same time the variable roller 42 in the second storage device 4 is moved in the direction of Arrow 44 moves downward, so that the stored in the second memory device loop is increased. In this case, the feed roller 1 and the discharge device 5 are at rest.

By the coupled movement of the variable roller 22 and the variable roller 42, a predetermined length of web material 6 to be processed is transported from the first storage device 2 in the direction of the arrow 25 to the work station 3, simultaneously processed web material 6 'in the direction of the arrow 32 from the workstation 3 transported away and processed web material 6 'in the direction of arrow 45 in the second storage device 4. As with this transport the feed roller 1 and the discharge device 5 are at rest, no large mass accelerations are required and the transport can be done at high speed.

The transport shown in Fig. 2 takes place until the variable roller 22 of the first storage device 2 is in an upper end position and the variable roller 42 of the second storage device 4 is in a lower end position, as shown in Fig. 3. Immediately after the end of the transport, the work station 3 is closed and enters a working state in which the web material 6 is processed. The unillustrated on the input side of the workstation arranged braking device thereby prevents further movement of the web material takes place in the workstation, and causes the tension acting on the web material when unrolling is decoupled from the web material located in the workstation.

By adjusting the distance of the upper end position of the variable roller 22 from the lower end position of the variable roller 22, the length of the sheet material 6 to be transported during the step described with reference to Fig. 2 can be adjusted.

Immediately after the start of working the workstation 3, as shown in Fig. 4, the chain strand 7 is moved via the drive 71 in the direction of the arrow 73 in the counterclockwise direction. At the same time, the feed roller 1 is set in rotation via the drive 10 and the discharge device 5 is set in rotation via the drive 50. As a result, on the one hand, the variable roller 22 of the first storage device 2 is moved downward in the direction of the arrow 26 to the lower end position and web material 6 to be processed simultaneously unrolled from the supply roller 1 and transported along the arrow 11 to the first storage device 2 and stored therein. on the other hand the variable roller 42 of the second storage device 4 is moved in the direction of the arrow 46 in its upper end position and processed web material 6 'from the second storage device 4 along the arrow 51 to the discharge device 5 is moved and rolled up in this.

This step takes place when workstation 3 is working, so that a long period of time is available. The required large mass acceleration for unrolling to be processed web material 6 and rolling up of processed web material 6 'can thus be done carefully and it can be a coupling between the movement of the variable rollers 22 and 42 and the drives 10 and 50 are realized, the decreasing mass of Feed roller 1 and the discharge device 5 taken into account. In this case, the control of the web tension in working workstation 3 can be controlled separately for unrolling and for rolling up. How the control of the web tension can take place, is eg in the US 4,753,059 described.

At the end of the step shown in Fig. 4, the packaging machine is again in the state shown in Fig. 1. During operation, the steps described are repeated cyclically.

This packaging machine has the advantage over the known prior art that the transport of material into the work station 3 and out of the work station 3 is uncoupled from unrolling of web material 6 to be processed and the rolling up of processed web material 6 ', since these steps differ from each other Periods of the working cycle take place. For a faster transport of the web material 6, 6 'is made possible with the workstation 3 open and there are no changes in the tracking of the web material, since only negligible mass acceleration occurs during tracking. The weight of the feed roller and The removal roller is only in the process steps that are performed when working workstation and for which much time is available. With this design, the tension of the web material can be kept substantially constant throughout the process.

Furthermore, this packaging machine makes it possible to easily adjust the length of the web material to be transported by adjusting the two end positions of the variable roller of the first storage device.

In the embodiment described with reference to FIGS. 1 to 4, the coupling of the first memory device to the second memory device is realized via a chain strand, but this coupling can also take place mechanically via a lever or electronically via an electronic shaft or via another suitable coupling.

The drive of the fast web transport in non-working workstation 3 can also be done on both sides of the workstation 3 arranged friction rollers. A realization by means of the web material laterally engaging chains is also possible, but then the use of web material of different widths is not possible without further adjustments.

Claims (18)

A method of unwinding web material in a cyclic intermittent web material packaging machine comprising the steps of: - Unrolling a predetermined length of web material to be processed (6) from a feed roller (1) and receiving in a processing direction in front of a workstation (3) arranged first memory (2) and removal of processed web material (6 ') of one in the processing direction behind the workstation (3) arranged second memory (4) at working workstation (3); - Feeding of processed web material (6) from the first memory (2) to the workstation (3) and simultaneous removal of processed web material (6 ') from the workstation (3) and recording in the second memory (4) when not working Workstation (3). Method according to Claim 1, in which, in the step of removal from the second storage (4), the processed web material (6 ') is fed to a discharge device (5) and rolled up on it. Method according to one of Claims 1 to 2, in which, when the workstation (3) is working in the workstation, parts of the web material (6) are cut out. A method according to any one of claims 1 to 3, wherein the removed processed web material (6 ') is a remaining frame of waste web material. Method according to one of claims 1 to 4, wherein the web tension is kept substantially constant throughout the process. Method according to one of Claims 1 to 5, in which, when the workstation (3) is working, the web material (6) is fixed on the input side of the workstation (3). Method according to one of Claims 1 to 6, in which steps which require mass acceleration of the feed roller (1) and the discharge device (5) are carried out only when the workstation (3) is operating. Method according to one of claims 1 to 7, further comprising the step: Adjusting the further transportable web length before processing web material (6). Packaging machine, which is designed for cyclically intermittent transport of web material with
a feed roller (1) for feeding web material (6) to be rolled off,
a first storage device (2) for receiving a predetermined length of sheet material (6),
a workstation (3) receiving intermittently fed web material (6) and delivering processed web material (6 '),
a second storage device (4) for receiving a predetermined length of processed web material (6 ') discharged from the work station (3) and
a removal device (5) for discharging processed web material (6 ') from the second storage device (4)
a control device which controls the packaging machine such that web material (6) to be processed is fed from the feed roller (1) to the first storage device (2) while the work station is operating, and processed web material (6 ') from the second storage device (4 ) is transported to the discharge device (5) and when the working station (3) is to be processed web material (6) from the first storage device (2) in the work station (3) is transported and processed web material (6 ') from the work station (3 ) is transported to the second storage device (4). A packaging machine according to claim 9, wherein the discharge device (5) is a roll for reeling processed web material (6 '). Packaging machine according to one of claims 9 or 10, in which the work station (3) is a sealing and cutting station. Packaging machine according to one of claims 9 to 11, wherein the first storage device (2) and the second storage device (4) are mechanically coupled together. A packaging machine according to any one of claims 9 to 12, wherein the first storage means (2) and the second storage means (4) are adjustable to receive a predetermined length of sheet material (6, 6 '). Packaging machine according to one of Claims 9 to 13, in which the first and second storage means (2, 4) store the web material (6, 6 ') in the form of a loop. Packaging machine according to one of claims 9 to 14, wherein the coupling of the first and the second memory means via a chain strand (7) or a belt is carried out. Packaging machine according to claim 15, which is designed such that the chain strand (7) or the belt is moved in working direction (3) for filling the first storage device (2) and emptying the second storage device (4) in a direction (73) and the chain strand (7) or belt when the work station (3) is not working to feed the web material (6) to be processed to the work station (3) and discharging processed web material (6 ') from the work station (3) in the opposite direction (72 ) is moved. A packaging machine according to any one of claims 9 to 16, wherein the first and second storage means (2, 4) are each constituted by two stationary rollers (20, 21; 40, 41) and a relatively movable sliding roller (22, 42) , Packaging machine according to one of claims 10 to 17, in which the feed roller (1) and the discharge device (5) each have a drive (10, 50) which sets them in rotation.

Images