EP2459332B1 - Device for forming deep-drawn containers - Google Patents

Description

The invention relates to a device for forming thermoformed containers according to the preamble of claim 1.

Such a device is known from US 4,562,717 known. In the known device to avoid irregularities in the cup wall, in particular of folds, an existing of an elastic material punch body is used. The punch body, which cooperates with a conically shaped die, which determines the outer shape of the cup, in this case has a slope between 0 degrees and 20 degrees. Further, the punch body has a centrally arranged recess whose shape is frustoconical, wherein in the recess additionally a cylindrically shaped receiving pin is arranged. During deep drawing of the container is in the end position of the punch body, in which the punch body is completely immersed in the die, the space between the cylindrically shaped pin and the punch body completely filled by a deformation of the punch body. Furthermore, the punch body lies on its outer circumference completely against the material web in the region of the die.

It has been found that with such a device, although the mentioned irregularities or wrinkles in the wall of the container can be avoided, however, that the stackability of the container is relatively poor. Here, a good stackability of the container is understood the property that nestled containers as completely as possible rest against the peripheral edge of the container, so that at a certain stack height as many containers stack each other and the stack has the same vertical orientation as possible. If this is not the case, both in the processing of the container in a packaging machine, which fills the containers and closes, as well as in the handling of the container, especially when removing individual containers from a container stack in a storage magazine, an increased effort required.

Based on the illustrated prior art, the invention has the object, a device for forming deep-drawn containers according to the preamble of claim 1 such that their stackability is improved. This object is achieved in a device for forming deep-drawn containers with the features of claim 1.

The invention is based on the idea that in the end position of the plunger body, in which this is in its lowest position in the die, between the plunger body and the container wall in the region of the opening portion of the container, a free space is formed. It has been found that thereby when moving out of the punch body from the die or during removal from the container this in the region of the opening of the container, which forms the region of the cup rim, have a very high, consistent accuracy or taper. As a result, the stackability of the container is significantly increased or improved.

Advantageous developments of the device according to the invention for molding deep-drawn containers are specified in the subclaims. All combinations of at least two features disclosed in the description, the claims and / or the figures fall within the scope of the invention.

Here, it is provided in a preferred embodiment of the invention for easy formation of the free space that the punch body has a region which is reduced in its cross-sectional area with respect to the initially reaching the material web in operative connection region of the punch body and that the first with the material web in Wirkverbindung reaching area has a height of at least 5 mm.

It is also preferred that the die has a taper angle of 1 degree to 20 degrees, in particular of 5 degrees to 12 degrees, and that the punch body in the container wall forming portion is cylindrical or has a taper which is smaller than the taper the container wall, wherein Konizitätswinkel the area especially between 0 degrees and 8 degrees. By this training containers are formed, which can be easily demolded.

A particularly simple producibility of the stamp body is achieved when the stamp body has at least two regions, one of which is a region of the container wall forming region and the other region of the region by the stamper body has the free space to the container wall.

Natural rubber, acrylonitrile-butadiene rubber or urethane rubber have been found to be preferred materials for the production of the stamper bodies.

Furthermore, tests have shown that in the materials mentioned it is advantageous if the punch body has a hardness of 50 ShA to 130 ShA, preferably from 70 ShA to 95 ShA.

The molding process can be facilitated if the material of the stamp body contains at least one additive, in particular a fluorine-based lubricant-improving additive, such as, for example, Teflon®.

In addition, it may be provided that the material of the stamp body contains a filler or a substance for reinforcement such as carbon black, silicon, clay or chalk.

For fixing and guiding the stamp body in the device, it may be provided that the stamp body is vulcanized onto a carrier element consisting of metal.

To achieve a high accuracy and dimensional stability of the container, it is proposed in a further advantageous embodiment that the punch body is annular and cooperates with an insert consisting of metal, which is connected to a carrier element consisting of metal. Through the use of a good centering of the web and a longer life of the punch body can be achieved.

In particular, it may be advantageously provided that a particular annular space is formed between the insert and the punch body.

In order to be able to form an embossed cup bottom, it is provided that the insert is formed on the side opposite the carrier element as a stamping plate having a structure (embossing edge) which forms the bottom region of the container.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings.

Fig. 1

einen ersten Stempelkörper zum Formen runder Behälter mit einem Trägerelement ohne Verwendung eines Einsatzes in einer Seitenansicht,

Fig. 2

einen zweiten Stempelkörper zum Formen runder Behälter unter Verwendung eines Einsatzes und eines Trägerelements im Längsschnitt,

Fig. 3

den in der Fig. 2 verwendeten Einsatz in einem Längsschnitt,

Fig. 4

einen dritten Stempelkörper zum Formen von Behältern, die eine in etwa achteckige Form aufweisen ohne Verwendung eines Einsatzes in Draufsicht,

Fig. 5

den Stempelkörper gemäß der Fig. 4 in einer Seitenansicht mit seinem Trägerelement,

Fig. 6 bis Fig. 8

den Herstellungsprozess eines Behälters unter Verwendung des in der Fig. 1 dargestellten Stempelkörpers während verschiedener Phasen jeweils in vereinfachten Längsschnitten und

Fig. 9:

mehrere ineinander gestapelte Behälter, welche unter Verwendung einer Vorrichtung gemäß der Fig. 6 bis 8 hergestellt wurden im Längsschnitt.

These show in:

Fig. 1

a first stamp body for molding round containers with a support element without using an insert in a side view,

Fig. 2

a second punch body for molding round containers using an insert and a carrier element in longitudinal section,

Fig. 3

in the Fig. 2 used insert in a longitudinal section,

Fig. 4

a third punch body for forming containers having an approximately octagonal shape without using an insert in plan view,

Fig. 5

the punch body according to the Fig. 4 in a side view with its carrier element,

Fig. 6 to Fig. 8

the manufacturing process of a container using the in the Fig. 1 shown punch body during different phases in each case in simplified longitudinal sections and

Fig. 9:

a plurality of containers stacked in one another, which are produced using a device according to the Fig. 6 to 8 were produced in longitudinal section.

In the Fig. 1 is a first punch body 10 for molding round containers 1 (see also Fig. 9 ). The rotationally symmetrical formed stamp body 10 may for example consist of natural rubber, an acrylonitrile-butadiene rubber or a urethane rubber, or at least contain these materials. Alternative stamp body materials are synthetic polyisoprene rubber, styrene-butadiene rubber, hydrogenated nitrile rubber, acrylic rubber, epichlorohydrin rubber, epichlorohydrin-ethylene oxide rubber, chloroprene rubber, polybutadiene rubber, butyl rubber or ethylene-propylene-diene monomers.

The hardness of the stamp body 10 is in this case between 50 ShA and 130 ShA, preferably between 70 ShA and 95 ShA.

The materials of the stamp body 10 may contain activators and / or accelerators for a later-mentioned vulcanization process, plasticizers or plasticizers, stabilizers, in particular against oxidation and ozone attack, processing aids, tackifiers and / or reinforcing agents or fillers. As reinforcing agents or fillers, the stamp body 10 may contain, for example, carbon black, silica, alumina, chalk or lime. The stamp body 10 may be provided with lubricants, for example fluoride-containing polymers or polyhalogenolefins, such as polytetrafluoroethylene (TEFLON®), α-boron nitride or graphite, at least on its shaping surface or through the entire stamp body material. Furthermore, dyes are also possible which make the stamp body 10 appear as desired or required in a desired color.

The punch body 10 has a through bore 11 in its longitudinal axis. Here, the diameter d of the bore 11 is about half of the diameter D of the punch body 10 ± 15 mm. Of the Diameter D of the punch body 10 corresponds to the inner diameter of the container 1 ± 3 mm.

The stamp body 10 has two regions 13 and 14. Here, the first region 13 has a larger diameter than the second region 14. The lateral surfaces 15, 16 of the regions 13, 14 are either cylindrical, or have a low conicity, wherein the angle α1 of the lateral surface 15 and the angle α2 of the lateral surface 16 can each be between 0 degrees and 8 degrees. The height h of the region 14 is between 0 mm and the total height H less 5 mm, wherein the diameter in the region of the lateral surface 16 can be up to 20 mm less than the diameter D.

The stamp body 10 described so far can be vulcanized onto a carrier element or a carrier plate 18. This can be done by a solvent-based two-component or one-component system or by means of a water-soluble binding system. Vulcanized stamper bodies 10 may be vulcanized by sulfur or peroxide treatment. The support plate 18 may be made of e.g. nitrided or case hardened or case hardened nitrided steel. Here, the metal carrier plate 18 has approximately an outer diameter which corresponds to the outer diameter of the punch body 10.

In the Fig. 2 a second punch body 20 is shown. The second plunger body 20 differs from the first plunger body 10 essentially by the use of a metal insert body 22 arranged in the bore 21. The insert body 22 has a cylindrical region 23 which widens in diameter on the side opposite the support plate 24. The upper side 25 of the insert body 22 may in this case be formed as an embossing plate, which by way of example has an elevated, radially surrounding embossing edge 27, which forms a corresponding recess in the bottom region of a container 1 ( Fig. 3 ).

In the longitudinal axis of the insert body 22, a receiving bore 28 is still formed, in which a screw, not shown, can be arranged, which screwed the insert body 22 with the support plate 24 or braced, and which may have a ventilation hole. The attachment of the punch body 20 with the support plate 24 via the screwed to the support plate 24 insert body 22, so that can be dispensed with a vulcanization of the punch body 20. The outer diameter or the shape of the insert body 22 is such that an annular clearance 29 is formed between the outer circumference of the insert body 22 and the inner circumference of the second punch body 20.

In the 4 and 5 a third punch body 30 is shown for forming approximately octagonal containers. Here, the length L of the inner length of the container corresponds to ± 3 mm. The length l corresponds to the length L less twice the wall thickness t ± 5 mm. The width B corresponds to the inner width of the container ± 3 mm. Furthermore, the inner width b of the width B is less than twice the wall thickness t ± 5 mm. The outer radius R is between 2 mm and 40 mm, while the inner radius r is approximately between 0.5 mm and 30 mm. The height H corresponds to the height of the containers. Here, too, the region of the plunger body 30 facing away from the carrier plate 31 can be enlarged relative to the region facing the carrier plate 31 corresponding to the two punch bodies 10, 20 (not shown). Also, according to the punch body 20, the punch body 30 may be formed using an insert. Further, the outer shape of the punch body 30 may be either cylindrical, or have a taper angle α3 of 0 degrees to about 8 degrees.

In the Fig. 6 to 8 Now, the manufacturing process of a container 1 is described from a material web 2 cut immediately before from a material web 2 by means of a device 40.

• Siegelschicht / Aluminiumfolie / Lack
  oder
• Siegelschicht / Aluminiumfolie / Kernschicht / Aluminiumfolie / Lack

The material webs 2 may contain, for example, an aluminum substrate. In particular, the aluminum substrate is at least one aluminum foil which is coated by lamination and / or extrusion, such as by coextrusion with, for example, plastics or paints. Typical webs may have one of the following two layer constructions, including the layers:

• Sealing layer / aluminum foil / paint
  or
• Sealing layer / aluminum foil / core layer / aluminum foil / lacquer

Typical sealing layers are, for example, polypropylene sealing layers in a thickness of 20 μm to 200 μm or of sealing layers of polyethylene in a thickness of 20 μm to 200 μm. The sealing layers can enter into a release-resistant connection with the seal or can form a peelable layer and the sealing layers can absorb pressure and impact forces on a case-by-case basis. The core layer can be, for example, a polypropylene or polyethylene, for example in the form of a film having a thickness of 20 μm to 200 μm. The aluminum foil may have a thickness of 20 .mu.m to 200 .mu.m, particularly preferably between 80 .mu.m and 160 .mu.m and in particular be a soft alloy, semi-hard alloy or three-quarter hard alloy. The applied lacquers can be, for example, per se known lacquers, such as acrylic lacquers, PVC lacquers, cellulose lacquers, stoving lacquers, epoxy-containing lacquers, nitro lacquers, etc.

• PP / Aluminium / Schaum / Aluminium
• PP / Aluminium / PP-Schaum-PP / Aluminium
• PP / Aluminium / PP-Schaum - PP
• PP / Aluminium / PP-Schaum
• PP / Aluminium / Schaum

Further applicable material webs may, for example, have one of the following layer constructions:

• PP / aluminum / foam / aluminum
• PP / aluminum / PP foam PP / aluminum
• PP / aluminum / PP foam - PP
• PP / aluminum / PP foam
• PP / aluminum / foam

The layer designated PP is in particular a polypropylene sealing layer directed against the inside of a container. An alternative possibility is a sealing layer, directed against the inside of a container, made of polyethylene. In a further embodiment it is possible to provide an inner PP or PE layer and a polyethylene or polypropylene adhesive layer adjacent thereto. The adhesive layer of polypropylene, resp. Polyethylene, may have a thickness of 10 microns to 60 microns. The sealing layers may for example have a total thickness of 20 microns to 200 microns.

The foam material may be a closed-cell plastic foam, for example made of a polyolefin, such as polypropylene (PP foam), or a polyethylene terephthalate foam (PET), used as C-PET or A-PET. The material combination PP foam PP indicates a multi-layer composite of two cover layers or covering films, for example a thickness of 12 to 200 μm, of polypropylene and a foam layer of e.g. Polypropylene or polyethylene terephthalate out. The foam layers can have a thickness of 500 μm to 2000 μm.

The aluminum has a thickness of advantageously 20 μm to 200 μm, preferably 80 μm to 160 μm, and is e.g. a soft, semi-hard or three-quarter hard alloy.

• PP / Aluminium / PP oder oPA (orientiertes Polyamid)
  oder
• PP / Substrat / Lack

Other applicable webs include:

• PP / aluminum / PP or oPA (oriented polyamide)
  or
• PP / substrate / paint

PP indicates a polypropylene sealing layer, PE a polyethylene sealing layer, whereby the sealing layer can be designed to be fully adhesive or peelable. In this case, layer thicknesses for the PP (polypropylene) of 20 microns to 80 microns are advantageous. The oriented polyamide may in particular be bi- or monoaxially oriented and have a thickness of 10 μm to 50 μm. The aluminum has a thickness of advantageously 20 .mu.m to 100 .mu.m and is, for example, a soft, semi-hard or three-quarter hard alloy. It can in turn be used the commercial paints.

• Siegellack / Stahl / Dekorationslack

erzeugt sein. Der Siegellack kann Polypropylen, PVC, PET oder Epoxy oder Kombinationen davon enthalten und kann in Mengen von 2 g/m² bis 12 g/m² eingesetzt werden. Der Stahl kann eine Dicke von 130 µm bis 170 µm aufweisen und ist vorteilhaft weich und tief vergütet. Die Lacke, so auch Dekorationslacke, sind handelsübliche Lacke, beispielsweise in verschiedenen Farbtönen.Another applicable web 2 can be made by extrusion coating electrolytically chromium coated steel (ECCS) of the exemplary construction:

• Sealing wax / steel / decorative varnish

be generated. The sealing wax may contain polypropylene, PVC, PET or epoxy or combinations thereof and may be used in amounts of from 2 g / m ² to 12 g / m ² . The steel may have a thickness of 130 microns to 170 microns and is advantageously soft and deeply tempered. The paints, including decorative paints, are commercially available paints, for example in different shades.

From the material webs 2 containers can be produced by means of the device 40 according to the invention, for example in plan view, rotationally symmetrical containers with outside diameters D of 12 to 150 mm and inside diameters D _i of 55 to 145 mm. The side wall angle can be between 1 and 20 °. The height of a container (H), related to the deep drawing ratio (β), can be represented as follows: $${\mathrm{H}}_{\mathrm{Max}}\mathrm{,}\mathrm{\approx }\mathrm{0}\mathrm{.}\mathrm{5}\mathrm{x}{\mathrm{D}}_{\mathrm{i}}$$

It is also possible to produce containers with non-rotationally symmetrical top view by means of the device according to the invention. For example, in plan view, oval or polygonal, such as rectangular or square, but also 5-, 6-, 8-square, etc. containers can be made. Typical radii for corner areas are between 2 and 40 mm at the outer edge and 0.5 to 30 mm at the inner edge (inner radius r) of the side wall. The length of the side edges is not critical. The height of a non-rotationally symmetrical container, based on the deep drawing ratio (β), is approximately: $${\mathrm{H}}_{\mathrm{Max}}\mathrm{\approx }\mathrm{2}\mathrm{.}\mathrm{5}\mathrm{x\; inner\; radius\; r}$$

In all the above-mentioned containers, a rolling edge 5 can be provided with a diameter of about 1 to 2.5 mm. The containers may have a sealing flange. The sealing flange, the hereinafter also referred to as a rolled edge 5 is suitably an endless sealing flange, and may for example be 2.5 to 5.0 mm wide. The side wall angle can be between 1 and 20 °.

The method with the present device allows for a production rate of, for example, 50 to 150 and in particular from 70 to 130 cycles / min. It has proved to be advantageous if the material web 2 is provided during processing in the device 40 with a layer of suitable lubricant, or oil or grease. In this case, layer quantities of 300 to 800 mg / m ² , in particular from 400 to 600 mg / m ^{2 have} proved to be advantageous.

The device 40 has a die 41 which determines the outer shape of the container 1 and interacts with the stamp body 10 by way of example. Here, the inner wall 42 of the die 41 has a Konizitätswinkel α4 of 1 degree to 20 degrees, in particular from 5 degrees to 12 degrees, which allows the removal from the die 41 and a nesting of containers 1 or improved. Furthermore, the stamp body 10 has a slightly smaller size on the side facing the die 41 than the die 41 in the region of its opening cross section 45.

By way of example, for deep drawing of the container 1, the die 41 of the device 40 in the direction of arrow 43 down against the rigidly arranged, and aligned with the die 41 in the longitudinal axis aligned punch body 10, wherein the web 2 by means not shown clamping means in a known manner and Way is clamped. Here, when the plunger body 10 is dipped into the die 41, the plunger body 10 is compressed both axially and radially, whereby the material web 2 is drawn between the area 13 of the plunger body 10 and the inner wall 42, without leaving any clearance between the area 13 of the plunger body 10 and the inner wall 42 and between the inner wall 42 and the die 41 are. As a result, the side wall 4 of the container 1 is formed.

How to particular on the basis of Fig. 8 recognizes, in which the punch body 10 has its end position with respect to the die 41 is between the side wall 4 and the region 14 of the punch body 10th a distance or clearance 44 is formed. This clearance 44 in this case consists in particular in the area of the later cup rim 5.

At the end of the deep-drawing process, the material web blank of the container 1 is formed in the region of its container edge, so that the rolled edge 5 is formed ( Fig. 9 ).

How best to use the Fig. 9 it is essential that the side walls 4 of the container 1 can be produced with a very high geometric accuracy or reproducibility by the special design of the stamp body 10. This makes it possible to achieve a good stackability of the containers 1, ie that, in the case of several containers 1 stacked one inside the other, they are arranged symmetrically to a longitudinal axis 46, the rolling edges 5 of the containers 1 resting over their entire circumference.

Claims (18)

1. Device (40) for forming deep-drawn containers (1), having a mould (41), which has a conical shape and interacts with a stamping body (10; 20; 30), which cooperates with a material web (2) when the stamping body (10; 20; 30) enters the mould (41), the stamping body (10; 20; 30) comprising a resilient material, at least at its outer periphery, and the stamping body (10; 20; 30) having a shape on the side facing the material web (2), the conicity of which is less than the conicity of the mould (41), characterised in that the stamping body (10; 20; 30) has a slightly smaller size than the opening region (45) of the mould (41), and in that the stamping body (10; 20; 30) has a region (41) which is reduced with respect to its cross-sectional area compared to the region of the stamping body (10; 20; 30) firstly operatively connecting to the material web (2), so that when the stamping body (10; 20; 30) is completely located in the mould (41), said stamping body has a clearance (44) with respect to the material web (2), at least in the later edge region (5) of the container (1).
2. Device according to claim 1, characterised in that the region (13) firstly operatively connecting to the material web (2) has a height of at least 5 mm.
3. Device according to either claim 1 or claim 2, characterised in that the mould (41) has an angle of conicity (α4) of 1 degree to 20 degrees, in particular from 5 degrees to 12 degrees, and in that the stamping body (10; 20; 30) is cylindrical in the region (13) forming the container wall (4) or else has a conicity, which is less than the conicity of the container wall (4), the angle of conicity (α1) of the region (13) in particular being between 0 degrees and 8 degrees.
4. Device according to claim 3, characterised in that the stamping body (10; 20; 30) has at least two regions (13, 14), of which one region (13) is the region forming the container wall (4) and the other region (14) is the region in which the stamping body (10; 20; 30) has the clearance (44) with respect to the container wall (4).
5. Device according to claim 4, characterised in that the other region (14) has an angle of conicity (α2) of between 0 degrees and 8 degrees.
6. Device according to any of claims 1 to 5, characterised in that the stamping body (10; 20; 30) is comprised of natural rubber, an acrylonitrile-butadiene rubber or a urethane rubber.
7. Device according to claim 6, characterised in that the stamping body (10; 20; 30) has a hardness of 50 ShA to 130 ShA, preferably of 70 ShA to 95 ShA.
8. Device according to either claim 6 or claim 7, characterised in that the material of the stamping body (10; 20; 30) contains at least one additive, in particular an additive for improving the sliding property based on fluorine, such as, for example, Teflon®.
9. Device according to claim 8, characterised in that the material of the stamping body (10; 20; 30) additionally comprises a filler or a material for reinforcement, such as, for example, carbon black, silicon, clay or chalk.
10. Device according to any of claims 1 to 9, characterised in that the stamping body (10; 20; 30) is vulcanised on a carrier element (18; 24; 31) comprised of metal.
11. Device according to any of claims 1 to 9, characterised in that the stamping body (20; 30) is annular and interacts with an insert (22) comprised of metal, which is connected to a carrier element (24; 31) comprised of metal.
12. Device according to claim 11, characterised in that an, in particular, annular clearance (29) is configured between the insert (22) and the stamping body (20; 30).
13. Device according to either claim 11 or claim 12, characterised in that the insert (22) on the side opposing the carrier element (24; 31) is configured as an embossing plate having a structure (embossing edge 27), which forms the base region of the container (1).
14. Use of a device (40) according to any of claims 1 to 13, characterised in that the device (40) serves to form a container (1) having, at least substantially, a round external shape.
15. Use according to claim 14, characterised in that the external diameter of the container (1) is between 12 mm and 150 mm.
16. Use of a device (40) according to any of claims 1 to 13, characterised in that the device (40) serves to form a container having a substantially polygonal external shape with rounded corners.
17. Use according to claim 16, characterised in that the corners of the container have an external radius of 2 mm to 40 mm.
18. Use according to any of claims 14 to 17, characterised in that the material web (2) is at least partially comprised of aluminium or steel, or in that the material web (2) is a laminated material web (2) using aluminum or steel, plastics material layers (for example, PP or PE) being used, for example, as the laminate layers and the thickness of the aluminium or steel layer being between 20 µm and 200 µm, in particular between 80 µm and 160 µm.

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