EP3401227B1 - Method for three dimensional forming of sheet material - Google Patents

Description

The invention relates to a method for three-dimensional forming of flat material made in particular of natural fibers, e.g. Paper or cardboard, with a deep-drawing plunger and a die, through which or into which the material is drawn.

Various methods for shaping flat material, in particular deep-drawing methods, are known.

The problem with these processes is that only thermoformable material, ie mainly plastic films, can be molded.

Papers and cartons are usually deep pressed, with significant wrinkling. document EP2829482A1 discloses a method according to the preamble of claim 1 and an apparatus according to the preamble of claim 9.

Such reshaped papers and cartons then have to be smoothed at their edges so that, for example, a lid can be sealed. Plastics are often applied for smoothing.

The object of the invention is to be seen in proposing a method which avoids the above disadvantages when forming paper and cardboard and which provides a deep-drawing method for these materials.

This object is achieved by the features contained in the characterizing part of claims 1 and 9.

As a result, wrinkles are smoothed out immediately, so that they are extremely finely distributed and no longer have a disruptive effect.

It has proven to be very advantageous if the material is clamped between the die and a so-called fold holder, as a result of which the material can slip in a targeted manner during shaping.

This largely prevents the formation of wrinkles.

It is also very advantageous according to the invention if the material is pressed partially or completely through the die during the forming process.

With partial pressing, the generated deformations have to be pushed upwards, whereas they can fall down with pressing.

Another very advantageous embodiment of the invention is when the die is designed as a plate, which can have a thickness less than or equal to the forming depth.

This ensures a very good forming result.

Furthermore, it is according to the invention if the initially cup-shaped molding, which is provided with a cylindrical, oval or angular side wall, is shaped by means of a mold.

As a result, the desired shape can be produced very easily and also different wall inclinations, conicity, can be generated. Other shapes are possible.

The deformation has different angles over its horizontal extent.

This allows a further improved adaptation to the desired shape. Shaped articles are conceivable which have different angles of the side walls over their horizontal extension. Any shape is conceivable.

Furthermore, it has proven to be extremely advantageous if the shaping is carried out in such a way that two conical sections are produced.

This can be used to create a cone that is flattened towards the edge. It is also very advantageous according to the invention if, after the molding has been filled, it is provided with a lid and closed.

In this way, the molding can be closed very well and securely and the contents protected.

It is extremely advantageous if the lid is sealed using a stamp.

This creates a simple and efficient way to connect the lid to the molding.

Furthermore, it has proven to be very advantageous if the molding is kept in a mold when it is closed.

This prevents undesired deformation.

It is also very advantageous according to the invention if the molding is trimmed when it is closed.

As a result, not only is the molding closed in one operation, but also an undesired excess is removed.

It has proven to be extremely advantageous according to the invention if the mold in which the molding is held is movably mounted and can be pressed down against a spring.

This creates a possibility for trimming in a simple manner. Instead of a spring, mechanical control or positive control can also be provided, for example.

Furthermore, according to a further embodiment of the invention, it has proven to be very advantageous if the edge of the molding is reshaped and / or interrupted when it is closed.

As a result, the edge can again be brought into an intended contour. When breaking, it is also possible to compensate for any tension in the cover and thus to avoid an undesirable drum effect.

A device which is very advantageous in accordance with the invention for carrying out the above-described method is present if a die and a deep-drawing piston are provided, the die being able to have a thickness which is less than or equal to the deep-drawing height.

This creates a very good possibility of deep-drawing flat-lying material, in particular paper material, that is to say to form it into a three-dimensional molding.

It is very advantageous if a counter stamp is provided.

This improves the deep-drawing process and can be controlled more precisely.

It is furthermore in accordance with the invention if a mold for receiving the molded article and a shaping stamp are provided which have a conical shape with at least two bevels.

This allows the vertically aligned walls of the preform to be widened in a targeted manner.

It is in accordance with the invention if the shaping punch has such a slope that the edge of the molding can slide along it, the slope being able to make an angle to the horizontal of approximately 20 °.

This means that the free end of the preform does not have to be treated again specifically. Rather, it is enough to widen with this stamp. A length and circumference compensation takes place by sliding along.

Furthermore, it has proven to be very advantageous according to the invention if a seal shape and a seal stamp are provided, it being possible for the size of the seal shape and the seal stamp to be coordinated with one another.

This allows perfect sealing of a lid on the molding.

According to a development of the invention, it is also extremely advantageous if a cutting device is provided.

For example, the molding and also the lid can be trimmed with a cutting device, if necessary.

It has also proven to be very advantageous if the sealing shape is movably mounted, which can be designed to be able to be pressed down against a spring.

This allows the sealing process to be controlled very well. It is conceivable that an edge surrounding the seal shape acts as a cutting device for trimming the molded article and lid, and so the sealing and trimming can be carried out in one work step. An additional cutting device is conceivable. Instead of a spring, mechanical control or positive control can also be provided.

Furthermore, it is very advantageous if the sealing mold and the sealing stamp have a contour which is capable of further deforming, pressing and / or breaking at least one edge of the molding.

This also allows several work steps to be combined in one process step.

According to a further development of the invention, it is also very advantageous if, when the molding is closed with a lid, the pressing or sealing force is limited by corresponding spring arrangements, regulations or the like.

This prevents, for example, that the material of the lid and / or molding is literally crushed. In addition, a too strong sealing force can also be negative with regard to the durability of the seam. Overall, the process is very easy to control and monitor.

Another very advantageous further development of the invention is also provided if moistening and / or a heating device is provided for the material.

As a result, the results of the forming steps can be significantly improved once again, since paper, cardboard and cardboard in particular are easier to deform and form.

The invention is illustrated below using an exemplary embodiment.

Fig. 1

einen flachliegenden Kartonzuschnitt für einen Formling

Fig. 2

eine Vorrichtung zum Formen bzw. Tiefziehen eines mit senkrechten Wänden ausgestatteten Vorformlings,

Fig. 3

eine Darstellung des Formlings.

Fig. 4

eine Vorrichtung zum Umformen des Vorformlings mit einer Form und einem Umformstempel

Fig. 5

eine Darstellung des Formlings,

Fig. 6

eine Darstellung einer Umformanordnung beim Aufweiten des Formlings,

Fig. 7

eine Detaildarstellung des Umformstempels,

Fig. 8

eine Vorrichtung zum Verschließen, Überbrechen und Besäumen einer fertigen Verpackung.

Show:

Fig. 1

a flat cardboard blank for a blank

Fig. 2

a device for molding or deep-drawing a preform equipped with vertical walls,

Fig. 3

a representation of the molding.

Fig. 4

a device for deforming the preform with a mold and a stamp

Fig. 5

a representation of the molding,

Fig. 6

a representation of a forming arrangement when expanding the molding,

Fig. 7

a detailed representation of the stamp,

Fig. 8

a device for closing, breaking and trimming a finished package.

With 1 is in Fig. 1 denotes a paper material blank that is three-dimensionally formed by means of a forming die 2 and a die 3.

The diameter of the forming die 2 plus twice the material thickness corresponds at least approximately to the diameter of the die 3.

The die 3 is formed as a recess in a material plate, preferably a steel plate.

The paper material blank 1 is pressed through the die with the forming die 2. As a result, a pot-shaped blank 34 is formed with a bottom 35 and cylindrical walls 36.

Due to the narrow gap between the forming die 2 and the die 3, any folds that may form in the paper or cardboard material 1 during the forming process are not only finely distributed, but also smoothed out immediately, so that they do not attract attention and have a disturbing effect.

The forming die 2 can either be pressed so deep into the die 3 that an edge still remains, that is to say the blank 34 is not pushed completely through the die 3, or the shaping die 2 is pressed so deep into the die 3, that no edge just remains, and the formed part 34 is at least pushed as far into or through the die 3 that it just ends in the die 3 or falls through it.

The die 3 can be made relatively thin, that is, the thickness of the die 3 can be significantly thinner than the height of the molded article 34. Important is the deflection of the horizontally lying, flat paper blank into the three-dimensional, pot-shaped form during the forming process.

During the forming process, an additional counter stamp 2a can also be provided, which clamps the paper material between the deep-drawing stamp and itself.

A hold-down device that holds the flat-lying material against the die 3 and enables a targeted, defined and controlled sliding of the flat-lying material can be provided.

However, since conical shapes are often not desired, but conical shapes, one possibility is shown below of converting these cylindrical shapes 34 into conical containers.

For this purpose, the formed part 34 is placed in a conical shape 4. A correspondingly shaped punch 5 moves from above into the blank and expands it. The blank is brought into a conical shape and pressed between the mold 4 and the punch 5.

A conical blank 40 is formed.

Both punch 5 and shape 4 can have two or more conical sections, as shown in the exemplary embodiment. A combination of conical and cylindrical sections is also conceivable.

It is not important that the base of the molding is actually circular. Oval, angular or irregular floor plans are also conceivable.

In order to ensure good formability, it is useful if the individual sections of the die 5 and the mold 4 are inclined at least 20 ° with respect to the horizontal. Due to this inclination, the open edge of the molding 34 can be on the Slide the slope of the punch 5, thereby avoiding compression of the cylindrical molding 34.

In a next step, the molded article 40 thus formed is filled and then closed with a lid 41. In this embodiment, the cover 41 is flat and is sealed onto the molded article. Other lids and other connection methods are conceivable.

When the cover 41 is sealed on, the edge of the molded article 40 is broken, that is, deformed further downward.

In this way it is prevented that the cover 41 is stretched and an undesirable drum effect occurs.

For this purpose, the molded article 40 is placed in a corresponding shape 6 and interrupted from above with a stamp 7. At the same time, the cover 41 already placed is connected to the molded article 40.

But it is also conceivable that no breaking takes place and the form 6 only has a horizontal outlet.

In the illustrated embodiment, the mold 6 is movably mounted in a holder 8, so that when depressed, i.e. Breaking the edge at the same time the edge and the lid 41 can be trimmed.

The edge between form 6 and holder 8 can be used for this. A separate separation device is conceivable.

The form 6 can be loaded in the holder 8 by means of a spring. Mechanical or hydraulic control is also conceivable.

Overall, a three-dimensional cup or a three-dimensional capsule is thus formed in a simple manner from a flat-lying paper or cardboard material.

Capsules of this type can be used, for example, for the preparation of hot or cold drinks, such as known plastic coffee capsules.

Depending on the desired storage period, these capsules can be equipped with a barrier layer or can also be packed in single or multiple packs.

Claims (14)

1. Method for three-dimensional reshaping of flat material (1) consisting of, in particular, natural fibres such as, for example, paper or cardboard, with a deep-drawing piston (2) and a die (3) through which or into which the material (1) is drawn, wherein the material (1) is clamped in place between the die (3) and a so-called blank holder, whereby the material (1) during the shaping can selectively sink, characterised in that the diameter of the deep-drawing piston (2) plus the material thickness of the material to be deep-drawn correspond at least approximately with the diameter of the die (3) and that the initially pot-shaped formed body (3), which is provided with a cylindrical, oval or polygonal side wall, is reshaped by means of mould (4), wherein the reshaping has a different angle over the horizontal dimension thereof.
2. Method according to claim 1, characterised in that the material (1) is pressed partly or completely through the die (3) during the reshaping.
3. Method according to claim 1 or 2, characterised in that the die (3) is constructed as a plate, wherein this can have a thickness smaller than or equal to the depth of reshaping.
4. Method according to any one of the preceding claims, characterised in that the reshaping is carried out in such a way that at least two conical sections are produced.
5. Method according to any one of the preceding claims, characterised in that after filling of the shaped body (40) this is provided with a cover (41) and closed, wherein the cover (41) can be sealed in place by means of an upper die (7).
6. Method according to claim 5, characterised in the shaped body during closing is held in a mould (6) and/or the shaped body is trimmed at the time of closing.
7. Method according to claim 6, characterised in that the mould (6) in which the shaped body is held is mounted to be movable and can be pressed down against a spring.
8. Method according to any one of the preceding claims, characterised in that the edge of the shaped body (40) is reshaped and/or interrupted during closing.
9. Device for carrying out a method according to any one of the preceding claims, wherein a die (3) and a deep-drawing piston (2) are provided, wherein the die (3) can have a thickness which is smaller than or equal to the deep-drawing height, characterised in that a mould (4) for reception of the shaped body (34) and a reshaping die (5) are provided, which has a conical shape with at least two chamfers, wherein the reshaping die has such a chamfer, and that the edge of the shaped body can slide along this, wherein the chamfer can adopt an angle of approximately 20° to the horizontal.
10. Device according to claim 9, characterised in that a mating die (2a) is provided.
11. Device according to one of claims 9 and 10, characterised in that a sealing mould (6) and a sealing upper die (7) are provided, wherein the sizes of the sealing mould and the sealing upper die can be matched to one another, wherein the sealing mould can be mounted to be movable, wherein this can be constructed to be able to be pressed down against a spring and/or wherein the sealing mould and the sealing upper die can have a contour which is capable of further reshaping, pressing and/or interrupting at least an edge of the shaped body (40).
12. Device according to any one of claims 9, 10 and 11, characterised in that during closing of the shaped body (40) by a lid (41) the pressing or sealing force is limited by appropriate spring arrangements, regulating means or the like.
13. Device according to any one of claims 9 to 12, characterised in that a cutting device is provided.
14. Device according to any one of claims 9 to 13, characterised in that moistening means and/or a heating device for the material is or are provided.

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