EP0933297B1 - Method and apparatus for packaging a load - Google Patents

Description

The invention relates to a method and a device for packaging a good, in particular a good that has edges in which the good to be packaged is at least one, preferably two, foils is enclosed by at least one, preferably two, film roll (s) are fed; then wrapped the film (s) around the goods and welded and separated from the at least one film roll, so that a film envelope is formed around the goods to be packed, the at least one Has a weld seam and protrudes openly on at least one side of the goods to be packaged, after which the foil wrapper is shrunk by the application of heat.

For packaging household appliances such as washing machines or tumble dryers as well in systems for packaging box loads, sack loads and similar goods so-called "foil handling systems" are available. Enclose such film handling systems the goods to be packed or the cargo to be packed e.g. with two sheets, which are fed from vertical film rolls. The film (s) will be wrapped and welded vertically around the load and separated from the film rolls, with a foil envelope with one or two vertical welds around the Charge is formed, which is open upwards and downwards. This foil envelope will with a heating device, for example in a shrink frame, with column burners or in a heated oven essentially only on the edges with protective elements z. B. are made of polystyrene, shrunk onto the packaging.

The film envelopes are essentially packed at one station Well attached and then the material with the foil cover to another station transported where the heat treatment takes place.

In the document DE 1901080 A become a procedure and a device according to the preambles of the claims 1 and 10 disclosed.

Because the film envelope is open at least at one end, if not both ends is and survives compared to the goods to be packaged, the disadvantage arises that the protruding Turn pieces of film over and randomly and disorderly on the top Arrange or underside. The result of this is that the shrinkage at the top of the load horizontal and vertical restoring forces in the film can cause the load to look unappealing after packaging. It is also problematic if foil sections turn outwards or in Accumulate corner or edge areas as this is when stacking packaging goods can cause them to skew and a larger stack packaging goods cannot be safely stored or transported. It is therefore extremely important for film handling systems, the shrinking process as precise as possible to be able to control and regulate. The vertical restoring forces are Shrinking process and the optical appearance u. a. depends on whether the foil edge is neatly arranged on or under the layer during or after shrinking and there despite the horizontal and vertical restoring forces caused by the shrinkage remains and is not pulled back over the edge area.

The invention aims to solve this problem and a method and an apparatus for packaging a good, in particular a good that has edges and corners has to create, which ensure a uniform appearance of packaged goods and the excessive formation of film folds and an uneven application of the film protrusions Avoid on the top and / or bottom of the goods.

The invention achieves this aim by the subjects of claims 1 and 10. Advantageous Refinements result from the assigned subclaims. Especially is advantageously ensured by the subject matter of the invention that the protruding free piece of film of the film envelope before or during the shrinking process not against the top or bottom of the good, but against the good in is essentially held upright and stretched while the essentially on the Cornering heaters the film in the corner areas on the packaged goods shrink. This ensures that the corners are clean on the top or against the underside of the packaged goods and the film sections in between smoothed under the influence of the horizontal and vertical shrinking forces and lie wrinkle-free against the top or bottom edge. For alignment in particular Various measures can be taken to stretch the excess film pieces of the film envelope be taken. So according to a first embodiment it is provided that An air jet is introduced into the open film piece centrally to the packaged goods. Since the The cross-section of the foil wrapper corresponds approximately to the cross-section of the goods to be packaged and, if necessary, the space between the bumper strips protecting the product is sealed from polystyrene or the like, the air jet from the top or Bottom of the goods to be deflected or redirected and along the surfaces of the Foil envelope derived. As a result, these film parts in the longitudinal direction of the extension of the foil envelope aligned or straightened and stretched, so that an irregular Place the foil edges on the top or bottom and thus the top described disadvantages can be avoided. This air flow can be heated so that Heat losses are avoided in the heating devices acting on the corners from the outside become.

The air flow thus causes the film edges or the film edge on all four sides is lifted vertically and straightened, while any corners - e.g. at a cuboid - at the same time slightly shrunk from the outside, causing the Place the film evenly over the cargo corners and and the film or its edges during / during / after the subsequent shrinking process on the load top or - stay bottom. The application of this procedure or the appropriately equipped one Device enables the realization of particularly similar charges that are almost wrinkle-free are and have wide film edges. Furthermore, the method according to the invention has the Advantage of easy controllability for the formation of uniform packaging, which allow easy stackability and also when stacking do not lie four to six batches of loads at an angle and tip over.

The at least one further air stream is expediently used to lift the film edges each fed through a tube, which is perpendicular and preferably centered is aligned with the open sides of the foil envelope. This variant of the invention enables a particularly cost-effective implementation with little design effort the invention into practice.

In an advantageous manner it can also be provided that the straightening or straightening of the protruding film pieces is carried out by means of a suction device which is attached to the outer or Developed inside or in the area of the film ends and ensures that the pieces of film are not arbitrary and disordered on the top or bottom of the Put the packaged goods down or be pressed on. However, the suction power must be like this be dimensioned so that the film corners under the influence of the heating device on the upper or shrink the underside of the packaged goods. Finally, it can be more advantageous Way can also be provided that the erection and alignment of the film end pieces by means of mechanical gripping devices, the gripping forces of which are dimensioned in such a way that the shrinking at least of the corner areas under the influence of those acting from the outside Heaters are not obstructed.

Further features, advantages and details of the invention emerge from the following Description of a preferred embodiment using the schematic single figure, according to which the working and operation of the invention Procedure should be described.

The figure shows as a device for carrying out the packaging method according to the invention schematically an essential part of the invention of a film handling system 1, such as they are used for packaging household appliances such as washing machines or tumble dryers becomes. The goods to be packaged 2 are made of two film rolls (not shown here) wrapped in two foils 3, 4.

A cutting device (also not shown here) enables the cutting Films 3, 4 from the film rolls, and a welding device enables welding the films in such a way that a film envelope 5 is formed around the goods 2 to be packaged, which in this case has two welds 6, 7 and on the top and bottom of the goods to be packaged 2 is open. Four upper (and four further, possibly lower) heating devices 7, 7 '(fan) allow at the corners (in addition to the actual heating or Shrinking device - e.g. an oven, a shrink column or a shrink frame) an additional heat supply at the upper and lower corners of the goods 2. With a device 8 in the manner of a tube for air supply centered over the top side of the goods 2 is from the direction of the upper side surface exposed before the shrinking process of the film envelope 5, a further air flow can be conducted into the interior of the film envelope 5.

Controlled shrinking of the corners of the packaged goods leads to the following reached: Since the film edges or the film edge on all neighboring pages slightly raised and straightening while shrinking the top corners at the same time, the film 3, 4 lies evenly and without folds over the cargo corners and the The film or its edges remain on during / after / after the subsequent shrinking the top of the load.

reference numeral

Film handling system

1

Verpackungsg

2

films

3, 4

foil envelope

5

welds

6, 7

heater

8th

Claims (16)

1. Method of packaging a product (2), which has edges, in which

   a) the product (2) to be packaged is surrounded by at least one, preferably two, film(s) (3, 4), which may be supplied from at least one, preferably two, film rolls,

   b) the film(s) (3, 4) is/are wrapped around the product (2) and welded and separated from the at least one film roll so that a film envelope (5) is formed around the product (2) to be packaged which has at least one weld seam (6, 7) and projects open on at least one side of the product (2) to be packaged,

   c) the film envelope (5) is shrunk by the application of heat,

   d) a warm air current is applied from the exterior to edges and corners forming in the packaging process in order to shrink them,

   characterised in that the film edges and comers of the projecting film end(s) of the film envelope (5) are lifted or raised from the product to be packaged whilst they are acted on from the exterior by warm air and shrunk.
2. Packaging method as claimed in Claim 1, characterised in that an air current is guided into the interior of the film envelope (5) from the direction of at least one of the side surfaces of the film envelope which is open before the shrinking process.
3. Packaging method as claimed in Claim 2, characterised in that the air current is so guided into the free end of the film envelope (5) that the projecting film edges and corners produced in the formation of the film envelope are lifted/raised from the product to be packaged (2) by the air current whilst they are acted on from the exterior by warm air and shrunk.
4. Packaging method as claimed in Claim 1 or 2, characterised in that the air current for lifting the projecting film edges and comers is supplied by a pipe (8) which is directed perpendicularly and centred with respect to one of the open sides of the film envelope (5).
5. Packaging method as claimed in one of the preceding claims, characterised in that during the shrinkage process warm air is caused to flow from a heating body (7, 7') over the edges and comers of the product (2).
6. Packaging method as claimed in one of the preceding claims, characterised in that the product (2) to be packaged is substantially of parallelepiped shape and has a base surface and a top surface.
7. Packaging method as claimed in one of the preceding claims, characterised in that the film envelope (5) is open at the upper side and under side of the product to be packaged, whereby the supply of the air currents is also effected at the upper side and under side of the film envelope (5).
8. Packaging method as claimed in one of the preceding claims, characterised in that the cross-section of the film envelope (5) is selected to substantially correspond to the cross-section of the packaging product (2) so that the air current blown into the free end of the film envelope is deflected upwardly.
9. Packaging method as claimed in Claim 1, characterised in that the projecting film edges and comers are lifted during the shrinking of the comers by means of a suction device and/or mechanical gripping device.
10. Apparatus for performing the method as claimed in one of the preceding claims including

    a) at least one film roll for supplying at least one film (3, 4) for surrounding the product;

    b) a device for separating the film (3, 4) from the at least one film roll and a device for welding the film (3, 4) such that a film envelope (5) is formed around the product (2) to be packaged, which has at least one weld seam (6, 7) and projects open at at least one side of the product to be packaged,

    c) at least one heating device for shrinking the film envelope by the application of heat, which is so designed and is optionally provided with further heat supply or heating devices (7, 7') that the corners and edges are acted on from the exterior by a warm air current,

    characterised by a device for lifting or raising the film edges and comers of the projecting film end(s) of the film envelope (5) from the product to be packaged whilst it is acted on from the exterior with warm air and shrunk.
11. Packaging apparatus as claimed in Claim 10, characterised in that a device is provided with which an air current from the direction of the at least one free end of the film envelope (5) opened before the shrinking process may be guided into the interior of the free end of the film envelope (5) during or before the shrinkage process.
12. Packaging apparatus as claimed in Claim 10, characterised in that at least one pipe (8) is provided, through which the air current for lifting the film edges is supplied and which is directed perpendicularly and centred with respect to at least one of the open sides of the film envelope.
13. Packaging apparatus as claimed in one of Claims 10 to 12, characterised in that the at least one heating device has a plurality of heating bodies (7), which are so designed and arranged that warm air may flow over the comers of the parallelepiped shaped product during the shrinking process.
14. Packaging apparatus as claimed in Claim 13, characterised in that the film envelope (5) is open at the upper side and the under side of the product (2) to be packaged, whereby the supply of the air currents is also effected at the upper side and under side of the film envelope (5).
15. Packaging apparatus as claimed in Claim 10, characterised in that a suction fan is provided for raising and aligning the free ends of the film envelope.
16. Packaging apparatus as claimed in Claim 10, characterised in that for the purpose of raising the free ends of the film envelope one or more mechanical gripping devices are provided which grip the edges and/or comers of the projecting portions of the film.

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