EP2180965A1

EP2180965A1 - Multicolor printed and embossed lid for cream jars and method for producing such covers

Info

Publication number: EP2180965A1
Application number: EP08735025A
Authority: EP
Inventors: Holger Dede; Torsten Lafrenz; Matthias Trucks
Original assignee: Beiersdorf AG
Current assignee: Beiersdorf AG
Priority date: 2007-04-17
Filing date: 2008-04-04
Publication date: 2010-05-05
Also published as: WO2008125238A1; CH697701B1; DE102007018778A1; US20100116775A1; CN101663110A; RU2009141584A; BRPI0810437A2

Abstract

The invention relates to a painted, printed, and embossed deep-drawn lid, circular in the top view, made of aluminum, substantially in the form of a cylinder open on one side, wherein the imprint on the substantially flat surface has at least one contour also representing the contour of the embossment, obtainable by a sequence of the following process steps: (a) coating, particularly printing an aluminum plate with paint and/or colorant, (b) cutting the aluminum plate, (c) deep drawing, (d) embossing, (e) optionally edge rolling, wherein the steps (b), (c), (d), and optionally (e) are performed by a single tool.

Description

Multi-colored printed and embossed lid for cream cans and method for producing such covers

cans

Cans as packaging are well known. They can be made of various materials such as sheet metal, wood, plastic. Tin cans can be made of various metals, such as aluminum, steel, brass. The can can be made from the metal sheet by cutting, folding, grouting or soldering or welding. Another possibility is cold forming, in particular deep drawing. This eliminates the joining of sheet edges.

A can can be closed by a lid. Lids are conceivable in many different versions: there are hinged lid (cigar box), screw cap (oil can), plug (tea, biscuit or Niveadose). The lid can also be firmly connected to the can, as in a tin can.

Tin and / or lid are often designed for promotional purposes. For this purpose, the wall material can be coated with paint and paint, polished, labeled and / or embossed, depending on the manufacturer's request. Also, an inner coating with paint and paint, metal or plastic can be provided.

Cans can have many conceivable shapes: they can be rectangular, oval, round, octagonal, star-shaped or irregular (for example cat "Garfield", mouse "Mickey").

Most practical tins have a right angle between the bottom of the can and the wall, minimizing the space required to ship a variety of cans in a carton. In contrast, the lid is often not topside plan, but more or less strongly curved.

The subject of this invention are cans whose lids are designed and embossed multicolored, in particular lacquered and printed lids with lettering, which is both multicolored, as well as highlighted by embossing. In particular, the invention relates Lids deep-drawn in aluminum, round, curved and mass-produced.

The production of painted and deep-drawn aluminum lid is known. H the first high-speed live drives use a combined cut, pull, roll tool.

Such a tool is driven by a crankshaft and allows the production of 200 covers per minute. For each stroke, a lid is punched out of a metal sheet and then deep-drawn. The remaining edges on the edge of the lid are rolled so that the finished lid can be blown out.

A suitable tool is shown in Figure 1. The movements of the tool during a cycle are also shown. The figure shows both the principle of a conventional, as well as a cycle according to the invention.

The tool consists of a lower tool (1), (2), (3) and an upper tool (4) and (5). The lower tool has a core (1), a cutting ring (3) and a so-called fold holder (2). The fold holder (2) has a roll ring (2a) on the upper side facing the core (1).

The upper tool consists of a punch (4) and an ejector (5) around which the punch (4) is oriented. Such a combination of upper and lower tool is shown in Figure 1. The upper tool is driven by a crankshaft. At top dead center (0 °), the top tool is in its highest position during a cycle.

After the metal sheet has been passed over the lower tool, the cycle begins (Figure 1 A): The upper tool descends onto the lower tool and grips the metal sheet with the punch (4) and presses it against the fold holder (2). This happens, for example, with a crankshaft position of 135 ° (6/8 stroke).

As the crankshaft continues to move (Figure 1 B), the pleat holder (2) is lowered slowly, causing the cutting ring (3) to cut out a blank (also 135 °) from the plate.

As the cycle progresses to the bottom dead center (Figure 1 C), the punch (4) and pleat holder (2) slowly advance downwards, leaving the lid (.) Above the core (1) Ronde is formed slowly. This slowly slides material between the fold holder (2) and punch (4), whereby the side wall of the lid is formed. After about 7/8 of the stroke of the ejector (5) springs on the core (1). Now the top of the lid forms between core (1) and ejector.

During the last 1/8 of the stroke (Figure 1 D) the ejector (5) stops, the punch (4) continues to move. At bottom dead center (180 °), a hat-shaped structure is formed. The hat brim between core (1) and stamp remains.

During the upward movement after passing through the bottom dead center of the crankshaft (Figure 1 E), the pleat holder (2) is first conveyed upwards, whereupon the plunger (4) slowly recedes, but the ejector (5) stops 1/8 of the stroke. As a result, the remaining hat brim is pressed into the rolling ring of the fold holder and formed into a roll-shaped edge of the lid. This all happens between a crankshaft position of 180 to about 200 °.

Then the upper tool moves away from the lower tool (Figure 1 F) and takes the finished lid (Figure 1 G). This is blown out of the mold at a crankshaft position between 330 and 360 ° by an ejector stroke and an air flow (Figure 1 H).

A modern machine allows about 200 strokes per minute, so that about 12,000 lids per hour can be molded with a tool. Typically, 3 to 5 tools are used simultaneously, producing 36,000 - 60,000 lids per hour.

With such high throughputs, the metal sheet must be guided very precisely under the tools located at top dead center. In addition, it must be ensured that the distance between punch (4) in the upper and cutting ring (3) in the lower tool circumferentially around 3 1/100 mm = 30 microns. It must also be ensured that the drawing gap, ie the distance between core (1) and fold holder (2), is exactly sheet thickness. This is not a trivial task for the tools, which are exposed to quite heavy and high dynamic loads. Therefore, conventional upper tools are usually rotatably arranged because this greatly facilitates the alignment of the upper tool with the lower tool for setting a correct drawing gap.

In addition to the punch (4), the ejector (5) is a heavily stressed tool part. This has various holes, which are a fastening, disassembly and ventilation of the plant tool allows. Conventionally, the holes and ventilation holes in the ejector (5) are distributed over almost the entire ejector (5). As a rule, 8 - 12 holes are provided.

On the outer, to the punch (4) oriented towards the annular region of the ejector, however, no holes can be provided. This area represents a further clamping area of the tool, which is required for receiving the compression forces during rolling between the core (1) and the ejector (5).

If an additional embossing of the lid is provided, the lid must be shaped again separately in a subsequent method step after ejection from the cutting-pull rolling tool. It is relatively problem-free, if the embossing does not have to be aligned when z. B. on a monochrome lid simply embossing any orientation should be done.

It is very expensive, however, if the embossing may have only a single layer of the lid on the embossing tool, if z. B. a lettering should be highlighted both by the embossing as well as by the printing such. B. in a blue can lid with a white lettering "Nivea", in which the lettering should also be embossed over the entire area.

The alignment is hardly possible mechanically and would have to be done by hand. This may be the reason why such embossed and printed lids have not been found on the market at all.

An integration of the embossing step in the described automated cutting, pulling, rolling process is not readily possible:

On the one hand, the free rotation of the upper tool, which is required for aligning the upper tool on the lower tool, does not permit the projection of a lettering because the rotation can result in positions in which the positive stamping mold with the negative stamping mold on the upper or lower tool does not coincide. This resulted in damage to the embossing tools during one cycle.

On the other hand, there is absolutely no room for a lettering on the ejector (5) of the upper tool due to the numerous holes that serve for ventilation and fastening purposes. In addition, embossing pressure and embossing time must be sufficient to be able to characterize the rather elastic aluminum at all. The aluminum - which uses Mg-containing Al alloys that are considerably more elastic than pure Al - tends to spring back into its original shape with only a short-term impact force, making the freshly embossed edges slightly round or flat. With steel sheets this is no problem at all, because steel is much easier plastically malleable.

In addition, the in-process embossing of an aluminum lid results in the so-called frog effect: due to the tensioning of the material, the lid tends to make a noise when moving, reminiscent of that of a "children's cracking frog" and a well audible "tap". However, this is highly undesirable.

In addition, the tool must be designed so that even unembossed lid can be made. A tool that can only be used for embossed lids represents a considerably high cost burden for such a process.

Therefore, the tool would be provided so that it can be converted by a few simple steps to a standard tool without dies.

This bundle of objects is achieved by a process for the production of printed and embossed deep-drawn, in plan view, circular aluminum covers characterized by a sequence of inferring process steps:

(a) coating, in particular printing on an aluminum panel with lacquer and / or paint,

(b) trimming the aluminum panel,

(c) deep drawing,

(d) embossing,

(e) optionally Randollung, wherein the steps (b), (c), (d) and optionally (e) are performed with a single tool. The invention also encompasses a lacquered, printed and embossed deep-drawn, in plan view, circular cover made of aluminum, substantially in the form of a cylinder open on one side, in which the printing on the essentially flat surface has at least one contour which also defines the contour the pre- represented by a sequence of the steps referred to in the previous sentence.

The inventive method, it is possible to integrate the embossing process in the cut-train-roll process in a one-step process. The embossing force is sufficient to impress clean edges. It is easy to bring the embossing with the pre-painted lettering to cover, because the metal sheet is passed only once by a two-axis servo system under the embossing tool. Due to the special design of the ejector, it is possible to produce this can lid frog-free. In addition, the embossing dies embedded in the tools can be easily replaced by non-contoured dies. This makes it possible to produce unembossed lid on the same tool.

It is preferable if, in the case of all this, the dimensional deviation between the contour of the coating and the contour of the embossing is not more than 0.3 mm. It is preferred if the tool consists of an upper and a lower tool which are driven by a crankshaft and the lower tool has at least one core (1), a fold holder (2) with integrated rolling ring (2a) and a cutting ring (3) in that the upper tool has a punch (4) and an ejector (5) and the ejector has an embossing tool in the region of its center, ventilation and fixing holes outside the embossing tool and an annular clamping area (6) near the edge, the edges of which are at least 8 mm apart and which is free of drilling and mounting holes, wherein the upper tool is not freely rotatable and on the lower tool also has an embossing tool, wherein the embossing tools are aligned with each other and in the ejector and core (1) are let.

It is further preferred if the process steps (b) trimming the aluminum panel 135 to 145 ° after TDC, (c) thermoforming 140 to 170 ° after TDC, (d) embossing 170 to 180 ° after TDC, (e) possibly Randrollung 180 to 200 ° after TDC and (f) if necessary blow out 330 to 360 ° after TDC, in each case based on the position of the driving crankshaft. Further, it is particularly preferred if the embossing tool is provided on the core (1) with two mounting holes and two ventilation / Abdrückbohrungen. It is very particularly preferred if the tool has clearances between the lower and upper tool and between the punch (4) and the fold holder (2) and core (1) of 20 to 40 μm. Further, it is particularly preferred if the tool has an ejector, which is opposite to the later lid shape towards the open side of the lid towards at least 50% of its surface by 0.4 to 0.9 mm arranged opposite. It is particularly advantageous when manufacturing on a tool with Throughputs of at least 150, more preferably at least 190 pieces / min is performed. It is also of great advantage if the lid consists of an AlMg alloy with 2.5% Mg. The invention also includes a can containing a cosmetic preparation in which the lid has been prepared as described above.

Claims

claims

1.) Lacquered, printed and embossed deep-drawn, circular in plan view of aluminum, essentially in the form of a cylinder open on one side, in which the printing on the substantially flat surface has at least one contour, which also represents the contour of the embossing available by a sequence of concluding process steps:

(b) trimming the aluminum panel,

(c) deep drawing,

(d) embossing,

(e) Randollung if necessary, wherein the steps (b), (c), (d) and optionally (e) are performed with a single tool.

2.) Process for the production of printed and embossed deep drawn, in plan view, circular aluminum covers characterized by a sequence of concluding process steps:

(b) trimming the aluminum panel,

(c) deep drawing,

(d) embossing,

(e) if necessary, edge rolling, wherein steps (b), (c), (d) and optionally (e) are carried out with a single tool be led.

3.) Lid or method according to one of the preceding claims, characterized in that the dimensional deviation between the contour of the paint and the contour of the embossing is not more than 0.3 mm.

4.) Lid or method according to one of the preceding claims, characterized in that the tool consists of an upper and a lower tool, which are driven by a crankshaft and the lower tool at least one core (1), a fold holder (2) with integrated rolling ring (2a) and a cutting ring (3), the upper tool has a punch (4) and an ejector (5) and the ejector an embossing tool in the region of its center, ventilation and mounting holes outside the embossing tool and an annular clamping area near the edge (6) having its edges spaced at least 8 mm and free of drilling and mounting holes, the upper tool not being freely rotatable and also having an embossing tool on the lower tool, the embossing tools being aligned with each other and arranged in the ejector and core (1 ) are admitted.

5.) Lid or method according to one of the preceding claims characterized in that the method steps (b) trimming the aluminum panel 135 bis

145 ° after TDC, (c) deep drawing 140 to 170 ° after TDC

(d) embossing 170 to 180 ° after TDC,

(e) if necessary, edge rolling 180 to 200 ° after TDC and (f) if necessary blow out 330 to 360 ° after TDC, in each case based on the position of the driving crankshaft.

6.) Lid or method according to one of the preceding claims, characterized in that the embossing tool on the core (1) is provided with two mounting holes and two ventilation / Abdrückbohrungen.

7.) Lid or method according to one of the preceding claims, characterized in that the tool has clearances between the lower and upper tool and between the punch (4) and the fold holder (2) and core (1) of 20 to 40 microns.

8.) Lid or method according to one of the preceding claims characterized in that the tool has an ejector, which compared to the later

Lid shape to the open side of the lid at least 50% of its area by 0.4 to 0.9 mm is arranged opposite.

9.) Lid or method according to one of the preceding claims, characterized in that the preparation is carried out on a tool with throughputs of at least 150, more preferably at least 190 pieces / min.

10.) Lid or method according to one of the preceding claims, characterized in that the lid consists of an AlMg alloy with 2.5% Mg.

11.) can containing a cosmetic preparation, characterized in that it contains a lid according to one of the preceding claims.