DE20017318U1 - Device for welding and cutting foils - Google Patents

Description

Device for welding and cutting films

The present invention relates to a device for welding and cutting films, in particular film packaging, with a holding device to which a film section can be fixed, and a cutting device arranged adjacent to the holding device, by means of which a film end can be severed, and a welding device by means of which two film sections can be welded together.

DE 199 30 898 discloses a device for packaging elastic packages, whereby several individual packages are repackaged into one large package. During repackaging, a bundle of individual packages is pressed against a film wall in order to stretch the film around the package. The sides of the package are then folded and closed.

In such known devices for packaging objects in film, the film is fed in excess so that a certain tolerance compensation can take place. Due to the film being too large, an overhang forms in the area of a weld seam, which is unnecessary for the packaging. This overhang

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LOESENBECK · STRACKE · SPECHT · DANTZ - PATENT ATTORNEYS - EUROPEAN PATENT AND TRADEMARK ATTORNEYS

Registration text dated 28.09.2000 Page 2

The stand can be arranged on the front or back or on the side. The overhang of the film on one side has the disadvantage that the pack can be accidentally torn open by the film overhang and that it has an aesthetically detrimental effect on the customer. Simply cutting off the film overhang is problematic because the film waste then has to be removed in a laborious manner during the automated process.

It is therefore an object of the present invention to provide a device for welding and cutting films, in particular film packaging, in which the excess film is reduced to a minimum in a simple manner and * the cut-off excess film is then automatically disposed of.

This object is achieved with a device for welding and cutting films having the features of claim 1.

If a suction device for removing and collecting the severed film ends is provided next to the cutting device, the excess film end can be automatically removed and collected after cutting without having to intervene manually in the process or without the severed film ends lying around in a mess. This is particularly important in the area of hygiene product production.

According to a preferred embodiment of the invention, the suction device is arranged adjacent to a holding bar of the cutting device. As a result, the end of the film to be severed can be arranged particularly close to the weld seam in order to reduce the overhang to a minimum.

For effective removal of the cut-off film ends, the suction device has a feed shaft that extends essentially over the entire length of the holding bar. This ensures that individual film ends do not fall down next to the feed shaft. In order to have a compact suction device

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LOESENBECK · STRACKE · SPECHT · DANTZ - PATENT ATTORNEYS - EUROPEAN PATENT AND TRADEMARK ATTORNEYS

Registration text dated 28.09.2000 Page 3

In order to obtain the best possible performance, a suction shaft is connected to the feed shaft, the width of which is more than half the width of the feed shaft. The suction speed is increased by reducing the cross-section. The transition from the suction shaft to the feed shaft can be funnel-shaped, rounded or designed in a different way. It is also possible to provide a hose instead of the suction shaft. The suction shaft can thus be moved together with the cutting and welding device and can therefore be used flexibly for various processing operations. Furthermore, the close proximity between the suction device and the cutting device means that a comparatively high suction power can be achieved. Suction can also take place in the moving phase, so that the removal of the film overhang does not have a detrimental effect on the

cycle time.

Preferably, the suction device has a controllable valve flap for interrupting the air flow so that the suction effect at the feed shaft can be controlled in cycles. Since the time at which the end of the film is to be sucked off is fixed when welding and cutting the end of the film, the control can prevent the process from being disrupted by permanent suction at the feed shaft, for example because foreign bodies get into the feed shaft.

" According to a further embodiment of the invention, two upper retaining strips

and two lower holding strips are provided, between which an upper and a lower film end can be clamped, and between the two upper holding strips there is a cutting knife and a heating device for welding the film ends. This compact design makes it possible to keep the overhang small and to move the movable upper and/or lower holding strips comparatively quickly.

The invention is explained in more detail below using an embodiment with reference to the accompanying drawings.

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LOESENBECK · STRACKE · SPECHT · DANTZ - PATENT ATTORNEYS - EUROPEAN PATENT AND TRADEMARK ATTORNEYS

Registration text dated 28.09.2000 Page 4

Figure 1 is a perspective schematic view of an embodiment of a device according to the invention for welding and cutting films;
Figure 2 is a side view of the device of Figure 1; Figure 3 is an enlarged sectional detail view of the device of Figure 1; Figure 4 is a schematic side view of the suction device, and Figure 5 is a plan view of the suction device of Figure 4.

A device 1 for welding and cutting films has a vertically movable upper holding device 2 and a vertically movable lower holding device 3. A suction device 4 is provided on the lower holding device 3, which comprises an intake shaft 5 and a suction shaft 6.

As can be seen in Figure 2, a film end 7 is introduced between the upper holding device 2 and the lower holding device, which is to be welded and cut off. The film is used to package an object 8 which is surrounded by an upper and a lower film section.

To package the object 8, an upper film end 71 is laid loosely on a lower film end 72 at the side and clamped between the upper and lower holding devices 2 and 3, respectively. An upper outer holding strip 10 and a lower outer holding strip 13 engage the outward-facing side of the film end 70. On the opposite side, an upper holding strip 9 and a lower holding strip 14 clamp the section of the film end 70 facing the object 8. In this position, the film end 70 is clamped tightly between the holding strips 9, 10, 13 and 14. To sever the film end 70, a cutting knife 11 is provided, which can then be inserted into a slot 15 between the lower holding strips 13 and 14 in order to sever the film end 70. At the same time, before or after, the portion of the film end 70 facing the object 8 is heated and welded by means of a heating device 12.

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LOESENBECK · STRACKE · SPECHT · DANTZ - PATENT ATTORNEYS - EUROPEAN PATENT AND TRADEMARK ATTORNEYS

Anxneldetext dated 28.09.2000 Page 5

The severed part of the film end 70 is disposed of via the intake shaft 5 and the discharge shaft 6 of the suction device 4. The intake shaft 5 has approximately the same width as the holding strip 13 and opens into a discharge shaft 6 which has a small width or cross-section. The opening of the discharge shaft 6 into the intake shaft 5 can be rounded, funnel-shaped or otherwise designed.

The extraction shaft 6 is followed by a shaft 17 in which a controllable flap 18 is arranged so as to be rotatable about an axis 19. The suction power at the intake shaft 5 can be controlled by means of the flap 18. Preferably, the suction power is only used specifically when cutting the film end 70. At the

* Shaft 17 is connected to a suction fan (not shown). The separated

Any excess film can then be collected and recycled in any way.

The device shown is preferably used in secondary packaging systems in order to combine smaller packages with film packaging into a large overall package and to form a ready-to-sell packaging unit. In such ready-to-sell packaging units, the film overhang adjacent to the weld seam is thus reduced to a minimum in a simple manner by using the device according to the invention.

Claims (7)

1. Device for welding and cutting films, in particular film packaging, with a holding device ( 2 , 3 ) to which a film section ( 7 ) can be secured, and a cutting device ( 9 , 10 , 11 , 13 , 14 ) arranged adjacent to the holding device ( 2 , 3 ) by means of which a film end ( 70 ) can be severed, and a welding device ( 12 ) by means of which two film sections ( 71 , 72 ) can be welded together, characterized in that a suction device (S. 6) for removing and collecting the severed film end ( 70 ) is provided adjacent to the cutting device ( 9 , 10 , 11 , 13 , 14 ). 2. Device according to claim 1, characterized in that the suction device is arranged adjacent to a holding bar ( 13 ) of the cutting device ( 9 , 10 , 11 , 13 , 14 ). 3. Device according to claim 1 or 2, characterized in that the suction device has an intake shaft ( 5 ) which extends substantially over the entire length of the holding strip ( 13 ). 4. Device according to claim 3, characterized in that the intake shaft ( 5 ) is followed by a suction shaft ( 6 ), the width of which is smaller, preferably more than half smaller, than the width of the intake shaft ( 5 ). 5. Device according to one of the preceding claims 1 to 4, characterized in that the suction device has a controllable valve flap ( 18 ) for interrupting the air flow. 6. Device according to one of claims 1 to 5, characterized in that two upper holding strips ( 9 , 10 ) and two lower holding strips ( 13 , 14 ) are provided, between which an upper ( 71 ) and a lower film end ( 72 ) can be clamped, and between the two upper holding strips ( 9 , 10 ) a cutting knife ( 11 ) and a heating device ( 12 ) for welding the film ends ( 71 , 72 ) are provided. 7. Device according to claim 6, characterized in that the feed shaft ( 5 ) is attached to the lower outward-facing retaining strip ( 13 ).