EP1808374B1 - Film packaging machine for packaged goods of varying size - Google Patents

Description

The invention relates to a device for wrapping and welding of Packgutstücken of varying size in film material, especially in thermo shrink film.

From the DE 196 21 205 C2 a device is known, are surrounded with the Packgutstücke tubular of a film web. In each case in front of and behind a packaged piece of goods, the film tube is cut off with a separating welding knife oriented transversely to the transport direction of the film web. With further arranged on both sides of the Packgutstückes Trennschweißmessem lateral separation welds are then generated, thereby closing the film tube as a packaging bag on all sides around the Packgutstück. In this case, the length of the separated film tube sections can be adapted to the detected with sensor means length of Packgutstücke. However, since the width of the packaging bag is determined by the fixed distance of the lateral Trennschweißmesser, an adaptation to the width of the Packgutstücke is not possible, but lateral projections can arise. In order to remove these, the transport direction of an already sealed Packgutstückes is changed by 90 ° and separated the already closed film packaging with another transverse to the new transport direction separating welding immediately before or behind the Packgutstück in a final separation process.

In the publishing industry, books and stacks of books of constantly changing sizes must be packaged in small numbers. For example, formats between DIN-A4 and DIN A6 occur, with the height of 5 mm for single pieces up to 200 mm may vary in stacks.

In banderolier packaging machines of the conventional type, the shrink-wrapped film casings enclosing the packaged goods are cross-welded and open on both sides, the edges of the foil casings then being partially closed by shrinking the film material in a heated shrink tunnel. The film width is selected here according to the dimensions of the highest stack of packaged goods with the largest format, which is to go through the packaging machine. Since the width of the film envelopes can not be reduced in this case, this results in a lower limit of formats of individual pieces, below which can no longer be effectively packaged with this procedure due to excessive lateral projections. For stacks with larger formats of Packgutstücken there is the disadvantage that large lateral areas of the wrapped Packgutstücke remain open and unprotected.

From the US 5,299,410 a device according to the preamble of claim 1 is known. Thereafter, the size of the individual Packgutstücke is determined by measurement and supplied to the respective size foil pieces fed to a sealing unit. This comprises a Querversieglungseinheit and two lateral Längsversieglungseinheiten, each having inversely closable e pairs of sealing blades. The two lateral Längsversieglungseinheiten are adjustable at a distance from each other by opposite adjustment.

Proceeding from this, the present invention has the object to improve a device of the type mentioned so that Packgutstücke with a large range of stack heights and formats in varying order can be packed safely and with increased quality using simple actuation means.

• erste Transportmittel zum Längstransport,
• Sensormittel zum Erfassen der Breite der einzelnen Packgutstücke,
• eine Vorrichtung zur Erzeugung eines in Transportrichtung abziehbaren vertikalen Folienvorhanges, der die Packgutstücke von der vorderen Stirnseite aus umhüllt,
• eine Quertrennschweißvorrichtung zum Verschweißen und Abtrennen von Folienhüllen entlang der hinteren Stirnseite der Packgutstücke,
• zweite Transportmittel zum Längstransport,
• paarweise angeordnete, in Transportrichtung verlaufende Längstrennschweißvorrichtungen zum Längsabtrennen der seitlichen Überstände des Folienmaterials mit geringem Abstand entlang der beiden Längsseiten der Packgutstücke,
• Verstellmittel zum automatischen Verstellen der Längstrennschweißvorrichtungen quer zur Transportrichtung auf die jeweilige Breite der einzelnen Packgutstücke, wobei die Längstrennschweißvorrichtungen zwei in Transportrichtung parallel zueinander verlaufende schneidenförmige Oberstempel und jeweils die Breite des Verstellbereichs der Oberstempel überdeckende Unterstempel umfassen, die ortsfest in der Ebene der Transportmittel angeordnet sind

The solution consists in a device for wrapping and welding of Packgutstücken of varying size in film material comprising:

• first transport means for longitudinal transport,
• Sensor means for detecting the width of the individual packaged goods,
• a device for producing a removable in the transport direction vertical film curtain, which wraps the Packgutstücke from the front end face,
• a cross-cutting welding device for welding and separating foil sheaths along the rear end face of the packaged goods,
• second transport means for longitudinal transport,
• arranged in pairs, running in the direction of transport longitudinal separation welding devices for longitudinal separation of the lateral projections of the film material at a small distance along the two longitudinal sides of the Packgutstücke,
• Adjusting means for automatically adjusting the longitudinal separating devices transverse to the transport direction to the respective width of the individual Packgutstücke, wherein the longitudinal separation welding two in the transport direction parallel to each other extending blade-shaped upper punch and respectively the width of the adjustment of the upper punch overlapping lower punch, which are arranged stationarily in the plane of the transport

The said lateral distance of the welds from the respective Packgutstück can be optimized by adjusting the transverse distance of the longitudinal separation welding devices from each other, depending on size, taking into account both the width and the height of the individual Packgutstücke. For this purpose, sensor means are provided for detecting at least the longitudinal dimensions and the transverse dimensions of the individual Packgutstücke viewed in the transport direction. The detected data is processed in a suitable control unit and converted into control signals for controlling the adjustment means.

It is proposed that run between the lower punches third transport means for the longitudinal transport of Packgutstücke whose width is less than the minimum expected width of Packgutstücke. In order to control the film casings with the possibly large lateral projections is provided that the second transport and the third transport each consist of a perforated endless belt with underlying vacuum box, that laterally next to the lower punches fourth transport means for longitudinal guidance of the supernatants or the waste portions of the film material are arranged, and that these fourth transport means each consist of a perforated endless belt with underlying vacuum box. From the same point of view, it is proposed that in each case laterally next to the upper punches parallel to these extending roller strips are arranged with a plurality of rollers, which are lowered to the fourth means of transport.

In the case of the method which can be carried out there are no continuous film edge strips which could then be wound up, but individual film sections of different length and width, which are difficult to handle. Therefore, it is ensured that the edge of the lower film layer is fixed continuously by negative pressure. For the second conveyor belt between transverse and longitudinal welding with rows of holes and attached vacuum boxes is equipped, and laterally next to the lower punches of the longitudinal welding devices are as fourth conveyor belts also perforated vacuum belts. As a result, a flat resting and the edge region of the lower film layer is ensured and the film sections are located before and after the longitudinal separation welding in a defined position. The edge of the upper film layer is initially connected only by the Querscheißnaht with the lower film layer. The longitudinal welding dies are also used to weld the upper and lower film layers continuously, even at the longitudinal side of the film projection facing the packaged item. Due to the applied packaging principle, the upper layer of film is twice as long as the lower layer of film. By lowerable next to the longitudinal welding dies rolling strips is therefore enforced that the film projection is still flat on the lateral vacuum bands. These roller strips can be brought into action before the longitudinal separation welding or immediately afterwards for the subsequent removal of the waste components.

The third conveyor between the lower longitudinal welding dies is also designed as a vacuum belt, the purpose in this case is that the longitudinal splice possibly glued to the lower punches foil even with light Packgutstücken whose liability to the conveyor belt due to low dead weight is not sufficient for sure to be able to replace.

• Aufsetzen oder Überführen der einzelnen Packgutstücke auf Längstransportmittel,
• Erfassen der Breite der einzelnen Packgutstücke,
• Einfahren der einzelnen Packgutstücke in einen senkrechten in Transportrichtung abziehbaren Folienvorhang,
• Einschlagen der einzelnen Packgutstücke jeweils von der vorderen Stirnseite der Packgutstücke ausgehend, wobei sich obere und untere Folienlagen auf die Ober- und Unterseiten der Packgutstücke legen,
• Quertrennschweißen der oberen und unteren Folienlagen quer zur Transportrichtung der Packgutstücke jeweils unmittelbar hinter der hinteren Stirnseite, so daß seitlich offene Folienhüllen entstehen,
• automatisches Einstellen von Mitteln zum Längstrennschweißen auf die jeweilige Breite der einzelnen Packgutstücke,
• Längstrennschweißen an den offenen Seiten der Folienhüllen an den Längsseiten der Packgutstücke.

The device makes it possible to carry out a method for wrapping and welding in packaged goods of varying size in film material, with the following steps:

• Placing or transfer of the individual packaged goods to longitudinal transport means,
• Detecting the width of the individual packaged goods,
• Retracting the individual items to be packaged in a vertical film curtain which can be pulled off in the transport direction,
• Starting the individual items to be packaged, starting from the front end side of the items to be packaged, with upper and lower layers of film laying on the upper and lower sides of the items to be packaged,
• Transverse cutting welding of the upper and lower film layers transversely to the transport direction of the Packgutstücke each directly behind the rear end side, so that laterally open film sleeves arise
• automatic setting of means for longitudinal separation welding to the respective width of the individual packaged goods,
• Longitudinal separation welding on the open sides of the foil covers on the long sides of the packaged goods.

In this case, the transverse spacing of the longitudinal welding means is individually adapted to the previously determined dimensions of the individual Packgutstücke to achieve optimum packaging size. The dimensions of the individual Packgutstücke can be detected with appropriate sensors. The acquired data are then converted into control signals for setting the transverse distance. Preferably, longitudinal welding involves welding the packaged items on all sides by welding the upper and lower film layers over the entire length of the items to be packaged.

This opens up the possibility of wrapping packaged goods with a very large size variation so that the film shrinkage effect can be brought into effect independently of the format, whereby an improved, at a short distance from the longitudinal sides, by the inventive lateral longitudinal arc welding, Covers closed on all sides. For Packgutstücken of particularly low height and / or binding strength can be dispensed with the process of the final thermal shrinkage, so that a round bending of the corners is avoided. Regardless of this, complete protection is provided by the foil packaging, which is closed on all sides. The welding on the longitudinal sides preferably takes place simultaneously and over the entire length, so that the total packaging time increases only insignificantly. The packaged goods are stopped for this purpose. The placement on a first conveyor belt can be done manually in a single machine, in a packaging machine line the transfer takes place automatically. A central insertion or transfer is favorable for the further process sequence. Automation of central insertion or transfer is possible with simple suitable means of delivery. The detection of the length and the width of the individual Packgutstücke can be done by means of suitable sensors, in particular contactless. In the further sequence of the process, it is provided that the joining of two film webs to a film curtain in front of the front end faces of Packgutstücke in a first transport position and the transverse cutting welding behind the rear end faces of the Packgutstücke in the same place in a second transport position, in particular for two consecutive Packgutstücke in one operation. In this case, it is provided that the transverse cutting welding takes place over the entire width of the film casings.

Since the individual film envelopes produced in this way are completely separated from one another and large lateral overhangs can occur in the case of small packaged goods, it is proposed that the parts of the lower film layer projecting laterally on the pack goods item be held by vacuum on the transport means during transport. Finally, it is provided that, if necessary, during the longitudinal separation welding, or at least during discharge, the parts of the upper film layer projecting laterally onto the items to be packaged are pressed onto the lower film layer, depending on the film quality.

It is also possible that the longitudinal separation welding of the lateral projections in parallel along the longitudinal sides of the Packgutstücke each time on the whole Length of the film covers erfotgt. The packaged goods are stopped here. The separated supernatants, ie the waste portions are removed in the transport direction. In this case, it is particularly advantageous to decouple the point in time and / or the speed of the further transport of the separated supernatants from the further transport of the wrapped package item in order to prevent re-sticking of the film material at the separation point. The individual separated supernatants should be removed as exactly as possible in the longitudinal direction. For this purpose, on the one hand conveyor belts with vacuum means, on the other hand in the deflection of these conveyor belts complementary upper Andrückbänder advantageous. After deflecting the separated supernatants down these can be collected in a container.

The packaged goods, which are welded in on all sides, are finally passed through an operating shrink tunnel in which the packaging is tightened and smoothed by thermal shrinking. Individual items to be packed whose packaging is not to be subjected to the shrinking process, d. H. In particular, small or thin pieces are either controlled via a switch in front of the shrink tunnel, or they are guided at increased speed through the shrink tunnel, at the same time the heater fan can be issued, so that no shrinkage process is initiated.

A preferred embodiment of a device according to the invention is shown in the drawings and will be described below.

Herein shows

FIG. 1

a banding device according to the invention in side view;

FIG. 2

according to the essential functional groups of the device FIG. 1 without frame parts in plan view.

The two figures will be described below together, unless reference is made to one of the figures.

Exclusively in FIG. 1 is a machine frame 11 as a whole recognizable, is marked on the left with an arrow E, the insertion direction of unpackaged Packgutstücke and right with an arrow A the direction or Abtransportrichtung for packaged Packgutstücke. The transport of Packgutstücke within the device takes place in the same transport direction T and is accomplished by a plurality of independently drivable conveyor belts 12, 13, 15. Of these, only the substructure and the drive means are shown, not the flexible and partially perforated endless belts in the narrower sense.

On the machine frame 11, an upper Folienabrollvorrichtung 16 for an upper film roll F1 and a lower Folienabrollvorrichtung 17 is arranged for a lower film roll F2. The withdrawn from the film rolls F1, F2 film is welded transversely between the conveyor belts 12, 13 to a vertical film curtain 18. This can be done by means of a cross-cutting device 14, which lies between the first conveyor belt 12 and the second conveyor belt 13, wherein a height-adjustable upper punch 19 by means of an actuating cylinder 24 is lowered to a lying in the transport height of the conveyor belts 12, 13 lower punch 20.

An unillustrated Packgutstück is viewed in the transverse direction preferably centrally placed on the first conveyor belt 12, wherein the side edges of the Packgutstückes are parallel to the side edge of the conveyor belts 12, 13, 15. There are automatic transfer and insertion devices used, which are not shown here, with which the process of preferably placing a Packgutstückes or a stack of Packgutstücken on the conveyor belt 12 can be done automatically. When the first conveyor belt 12 is driven, the item of packaged goods enters the film curtain 18 and pulls the film away from the film rolls F1, F2 in the transport direction. These are driven by a motor, so that the Packgutstück only takes out the lots from the film curtain. The Packgutstück is here pushed through the cross-cutting device 14 and on the second conveyor belt 13, wherein it pulls out a loop of film material, which lies with its lower film layer on the second conveyor belt 13 and lays with its upper film layer on top of the Packgutstückes.

The length of the Packgutstückes in the transport direction is detected without contact during transport on the conveyor belt 12 by a sensor 37 in conjunction with means for conveying path of the conveyor belt 12, the width of Packgutstükkes is detected between the conveyor belts 13 and 15 by light emitter and photocells 38, 39. The data determined here are stored and serve to control further components of the overall device.

As in FIG. 2 can be seen, the second conveyor belt 13 in the transport direction extending rows of holes 21, 22 which are connected to vacuum boxes in the interior of the endless belt, so that the lower film layer not only by the weight of Packgutstückes, but additionally fixed by the vacuum holding force on the second conveyor belt 13 becomes.

Immediately after the Packgutstück has completely passed through the cross-cutting device 14, the second conveyor belt 13 is stopped, said control is carried out according to the previously measured length of Packgutstükkes preferably in response to the detection of the transport path of the second conveyor belt.

Thereafter, the cross-cutting device 14 is actuated by the upper heated transverse punch 19 is lowered by means of the adjusting cylinder 24 on the lower transverse punch 20. In this case, the upper film layer and the lower film layer is closed to a loop-shaped circumferential film wrap around the Packgutstück, which is still open at the sides. At the same time, this film casing is separated from the original film curtain and the two films which are withdrawn from the film rolls F1 and F2 are connected by the transverse welding device 14 to form a new vertical film curtain 18. Thereafter, the conveyor belt 13 is driven again, at the same time or with a small time interval, a new Packgutstück placed on the conveyor belt 12 and can be retracted into the film curtain 18. From the conveyor belt 13, the wrapped Packgutstück is now transferred to the third conveyor belt 15 whose width is less than the width of the Packgutstückes with the lowest assumption width. Also in the conveyor belt 15 is a longitudinally extending row of holes 23 visible, which are connected to vacuum boxes in the interior of the conveyor belt 15. In each case laterally from the conveyor belt 15 longitudinal separating devices 25, 26 are arranged, the longitudinal, transversely to the transport direction adjustable upper punch 27, 28 and the entire width of the adjustment of the upper punch engaging lower punch 29, 30 have. The upper punches 27, 28 are each attached to a lower support 53, which can be lowered by a respective adjusting cylinder 54 vertically opposite to an upper support 58, wherein guide means 49, 50 are provided for parallel guidance on the respective upper support 58. The upper support 58 are by means of ball bushings on two with the machine frame 11 connected transverse guide rods 59, 60 symmetrically to each other transversely displaceable, wherein the displacement drive is effected by a drive motor 57 with an angle drive 61 via a toothed belt 62 which runs over a drive wheel 63 and a guide wheel 64 , In each case one of the two upper support 58 is clamped by means of a clamping piece 65, 66 on one of the two strands of the toothed belt, which results in drive of the toothed belt 62 an opposite transverse movement of the upper support 58 with the lower supports 53. As a result, the upper punch 27, 28 symmetrically to each other in the transverse direction adjustable so that their distance is individually adapted to the width of the Packgutstückes well adaptable, so that when lowering the heated upper punch 27, 28 on the lower punch 29, 30 each directly on the longitudinal sides the Packgutstückes the film packaging is separated laterally and in particular also laterally closed.

Since the transverse separation in the transverse cutting device 14 takes place in each case in the plane of the conveyor belts 12, 13, the upper film layer has a length which is greater by twice the height of the packaged product than the length of the lower film layer. Regardless of ensuring a reliable contact of the upper film layer on the lower film layer during longitudinal separation welding, height adjustable roller strips 33, 34 are provided, which lie directly to the side of the lower punch 29, 30 and co-operate with likewise drivable fourth conveyor belts 31, 32, when in their lowest position are lowered. The adjustment of the roller strips 33, 34, which takes place in a pivoting movement about horizontal axes extending in the transport direction, is effected in each case by adjusting cylinders 41, 42. The roller bars 33, 34 each have a plurality of rollers with transverse axes. The fourth transport belts 31, 32 again have rows of holes 35, 36 for generating negative pressure in their substructure. In addition, these lateral conveyor belts 31, 32 drive means 48 which are independent of the drive means 47 of the conveyor belt 15 to drive the conveyor belts differently after the welding off of the supernatants of the film material, so that a renewed sticking of the separated supernatants is prevented at the welds. The separated supernatants are thereby led away in the longitudinal direction and differentiated from the packaged piece of goods welded in on all sides by the drive 48 of the guide belts 31, 32.

In an end region of the fourth conveyor belts 31, 32, which is not detected by the vacuum boxes, the separated supernatants of bent over each of four unpowered rollers extending round belts 51, 52 are pressed onto the conveyor belts. Thereafter, they are collected by a container 40.

In addition to the already known drive motors 47, 48 for the conveyor belts 15, 31, 32, the drive motors 43, 44 of the unwinding devices 16, 17 and the drive motors 45, 46 of the conveyor belts 12, 13 can still be seen. Furthermore, a vacuum blower 56 is shown with a motor 55 for the vacuum boxes.

LIST OF REFERENCE NUMBERS

11

machine frame

12

conveyor belt

13

conveyor belt

14

Cross cutting welder

15

conveyor belt

16

film dispenser

17

film dispenser

18

film curtain

19

upper punch

20

lower punch

21

row of holes

22

row of holes

23

row of holes

24

actuating cylinder

25

Longitudinal separation welder

26

Longitudinal separation welder

27

upper punch

28

upper punch

29

lower punch

30

lower punch

31

guide band

32

guide band

33

roller strip

34

roller strip

35

row of holes

36

row of holes

37

sensor

38

light emitter

39

photocell

40

receptacle

41

actuating cylinder

42

actuating cylinder

43

Engine (16)

44

Engine (17)

45

Engine (12)

46

Engine (13)

47

Engine (15)

48

Motor (31, 32)

49

guide

50

guide

51

round belts

52

round belts

53

Carrier, lower

54

actuating cylinder

55

engine

56

fan

57

drive motor

58

Carrier, upper

59

Cross guide rod

60

Cross guide rod

61

angle drive

62

toothed belt

63

drive wheel

64

guide wheel

65

clamp

66

clamp

Claims (8)

1. A device for enveloping and sealing packages of varying sizes in film material, comprising

   first transport means (12) for longitudinal transport purposes;

   sensor means for recording the width of the individual packages;

   a device (16,17) for producing a vertical film curtain which can be pulled off in the direction of transport and which envelops the packages from the front end face;

   a transversely separating and sealing device (14) for sealing and separating film envelopes along the rear end face of the packages;

   second transport means (13) for longitudinal transport purposes;

   pairs of longitudinally separating and sealing devices (25, 26) for longitudinally separating the projecting ends of the film material along the two longitudinal sides of the packages;

   adjusting means (55 - 66) for adjusting the longitudinal separating and sealing devices (25, 26) transversely to the direction of transport to the respective width of the individual packages,

   characterised in
   that the longitudinally separating and sealing devices (25, 26) comprise two cutter-shaped upper dies (27, 28) which extend parallel relative to one another in the direction of transport, as well as two lower dies (29, 30) which each cover the width of the range of adjustment of the upper dies (27, 28).
2. A device according to claim 1,
   characterised in
   that between the lower dies (29, 30), there extend third transport means (15) for the longitudinal transport of the packages, whose width is smaller than the minimum package width to be expected.
3. A device according to any one of claims 1 to 2,
   characterised in
   that the second transport means (13) and/or the third transport means (15) consist of a punched infinite belt with a vacuum box positioned underneath.
4. A device according to any one of claims 1 to 3,
   characterised in
   that laterally outside the lower dies (29, 30), there are arranged fourth transport means (31, 32) for longitudinally guiding the laterally projecting ends and the remaining scrap of the film material.
5. A device according to any one of claims 1 to 4,
   characterised in
   that the fourth transport means (31, 32) consist of a punched infinite belt with vacuum boxes arranged underneath.
6. A device according to any one of claims 1 to 5,
   characterised in
   that laterally outside the upper dies (27, 28) there are arranged roller guides (33, 34) which extend in parallel relative to the latter and which comprise a plurality of rollers which can be lowered on to the fourth transport means.
7. A device according to any one of claims 1 to 6,
   characterised in
   that a shrinkage tunnel is subsequently connected in the direction of transport, wherein, more particularly in front of the shrinkage tunnel, there are provided ejecting means for packages and stacks of packages whose size is below that of a predetermined minimum format, or control means for the shrinkage tunnel for reducing or eliminating the effect of same on said packages or stacks of packages.
8. A device according to any one of claims 1 to 7,
   characterised by
   sensor means for recording at least the longitudinal dimensions and the transverse dimensions of the packages if viewed in the direction of transport.

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