DE102007018778A1 - Multi-colored printed and embossed lid for cream cans and method for producing such covers - Google Patents

Abstract

Lacquered, printed and embossed deep-drawn, in plan view circular lid made of aluminum, substantially 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, obtainable by a Sequence of the following process steps: (a) coating, in particular printing, an aluminum sheet with varnish and / or paint, (b) trimming the aluminum sheet, (c) deep drawing, (d) embossing, (e) optionally edge rolling, the steps (b ), (c), (d) and, if applicable, (e) be carried out with a single tool.

Description

cans as packaging are sufficient known. You can made of different materials such as sheet metal, wood, Plastic. Tin cans can made of different metals, for example Aluminum, steel, brass. The can can from the sheet metal through Cutting, folding, sheeting or soldering or welding getting produced. Another possibility is cold forming, especially deep drawing. It eliminates the joining of Sheet metal edges.

A Can be closed by a lid. Lids are in many different designs conceivable: there are hinged lid (cigar box), screw cap (Oil cell), Plug-in lid (tea, biscuit or level can). The lid can also be firm be connected to the can, as with a tin can.

can and / or lids are often designed for promotional purposes. This can do that Wall material coated with lacquer and paint, polished, labeled and / or embossed will be, depending on the manufacturer's request. Also an interior coating with paint and paint, metal or plastic can be provided.

cans can have many conceivable forms: they can be rectangular in plan, oval, round, octagonal, star-shaped or irregular (eg. As hangover "Garfield", mouse "Mickey") may be formed.

The Most practical cans are right angles between can bottom and wall on, which reduces the space required for shipping keeps a large number of cans in a carton low. On the other hand the lid is often not topside plan, but more or less strongly arched.

object this invention are cans, the cover designed multi-colored and embossed are, in particular painted and printed lids with a lettering, which is shown in both colors, as well as highlighted by embossing becomes. In particular, the invention relates to covers made of aluminum deep-drawn, round, arched and can be produced in mass production.

The Production of painted and deep-drawn aluminum lid is on known. High throughput manufacturing processes use a combined one Cutting, pulling, rolling tool.

One such tool is over A crankshaft driven and allowed in the minute production of 200 lids. For each stroke, a lid is punched out of a metal sheet and subsequently deep-drawn. The remaining edges are rolled on the edge of the lid, so that the finished lid blown out can be.

A suitable tool is in 1 shown. 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 ) on. The fold holder ( 2 ) points to the core ( 1 ) turned upside down a rolling ring ( 2a ) on.

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

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

As the crankshaft continues to move ( 1B ), the fold holder ( 2 ) is slowly lowered, whereby the cutting ring ( 3 ) cuts out a blank from the metal sheet (also 135 °).

In the further course of the cycle to bottom dead center ( 1C ) back stamp ( 4 ) and wrinkle holders ( 2 ) slowly downwards, leaving over the core ( 1 ) the lid is slowly formed from the round blank. It slowly slips material between the fold holder ( 2 ) and stamps ( 4 ), whereby the side wall of the lid is formed. After about 7/8 of the stroke, the ejector ( 5 ) on the core ( 1 ) sprung up. Now the top of the lid forms between core ( 1 ) and ejector.

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

During the upward movement after passing through the bottom dead center of the crankshaft ( 1E ), the wrinkle holder ( 2 ) promoted to the top, whereupon the stamp ( 4 ) slowly recedes, the ejector ( 5 ) but still 1/8 of the stroke stops. 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 ( 1F ) and takes the finished molded lid with ( 1G ). This is at a crankshaft position between 330 and 360 ° by a Ausstoßerhub and an air flow ( 1H ) blown out of the tool.

A Modern machine allows about 200 strokes per minute, so that can be about 12,000 lids per hour can be molded with a tool. Usually 3 to 5 tools are used simultaneously, yielding 36,000-60,000 Lid can be produced 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 the stamp ( 4 ) in the upper and cutting ring ( 3 ) in the lower tool circumferentially about 3 1/100 mm = 30 microns. Likewise, it must be ensured that the drawing gap, ie between core ( 1 ) and wrinkle holders ( 2 ) distance, exactly sheet thickness is. 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.

Next to the stamp ( 4 ) is the ejector ( 5 ) a heavily used tool part. This has various holes, which allows attachment, disassembly and ventilation of the tool. Conventional way are the holes and ventilation holes in the ejector ( 5 ) over almost the entire ejector ( 5 ). As a rule, 8-12 holes are provided.

On the outside, to the stamp ( 4 ) oriented towards the annular area of the ejector, however, no holes can be provided. This area represents a further clamping area of the tool, which is used to absorb the compression forces during the rolling process between the core (FIG. 1 ) and the ejector ( 5 ) is required.

Becomes one more extra embossing provided the lid, the lid must in a subsequent Process step after ejection from the Schnittzugrollwerkzeug again coined separately become. It is relatively problem-free if the embossing is not aligned must if z. B. on a monochrome lid simply embossing arbitrary Orientation should take place.

Very It is complicated, however, when the coinage only a single layer the lid on the stamping tool may have, if z. B. a lettering both by the coinage as should also be highlighted by the printing such. B. at a blue can lid with a white lettering "Nivea", in which the lettering additionally be coined completely should.

The Alignment is hardly possible by machine and would have to be done by hand. This is likely the reason for this be that such embossed and printed lids so far did not occur on the market at all.

An integration of the embossing step in the described automated cutting, pulling, rolling process is not readily possible:
Firstly, the free rotation of the upper tool, which is required for alignment of the upper tool on the lower tool, not the projection of a lettering, because the rotation can result in positions in which the positive embossing mold with the negative embossing 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, on the ejector ( 5 ) of the upper tool due to the numerous holes that are used for ventilation and fastening purposes, no space for a lettering.

Furthermore have to embossing and minting time enough be able to shape the very elastic aluminum at all. The aluminum - used become Mg-containing Al alloys, which are considerably more elastic than pure Al - tends to be only for a short time Embossing force to jump back in the initial shape, making the freshly embossed edges slightly round or to become flat. With steel sheets, this is not a problem at all, because Steel is much easier plastically malleable.

Furthermore it comes with the in-process imprinting An aluminum lid for the so-called frog effect: By material tension when moving, the lid tends to make a sound reminiscent of that of a "children's bug-frog" well audible "plöpp." This but is very much undesirable.

In addition, the tool must be ge staltet be that even unembossed lid can be made easily. A tool which can be used exclusively for embossed lids represents a considerably high cost burden for such a process.

Therefore would be that Provide the tool so that it can be made by a few simple steps Standard tool without embossing stamp convert is.

• (a) Beschichten, insbesondere Bedrucken einer Aluminiumtafel mit Lack und/oder Farbe,
• (b) Beschneiden der Aluminiumtafel,
• (c) Tiefziehen,
• (d) Prägen,
• (e) ggf. Randrollung, wobei die Schritte (b), (c), (d) und ggf. (e) mit einem einzigen Werkzeug durchgeführt werden. Die Erfindung umfasst auch einen lackierten, bedruckten und geprägten tiefgezogenen, in der Aufsicht kreisförmiger Deckel aus Aluminium, im wesentlichen in Form eines einseitig offenen Zylinders, bei dem die Bedruckung auf der im wesentlichen ebenen Fläche zumindest eine Kontur aufweist, die auch die Kontur der Prä gung darstellt erhältlich durch eine Abfolge der im vorhergehenden Satz genannten Schritte.

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 includes a 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 the contour of the pre represented by a sequence of the steps referred to in the previous sentence.

By the inventive method Is it possible, in a one-step process, the embossing process in the cut-pull-roll process to integrate. The stamping force enough, to stamp clean edges. It succeeds easily, the coinage with the prepainted lettering to cover, because the Metal sheet only once by a biaxial servo system is passed under the embossing tool. Due to the special design of the ejector manages this can lid frog-free to be able to produce. About that In addition, the embedded in the tools embossing dies can be easily replace with non-contoured dies. This is it is possible also unembossed Make 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 at least one core ( 1 ), a fold holder ( 2 ) with integrated rolling ring ( 2a ) and a cutting ring ( 3 ), the upper tool a punch ( 4 ) and an ejector ( 5 ) and the ejector has an embossing tool in the region of its center, ventilation and fastening bores outside the embossing tool and an annular clamping region ( 6 ), the edges of which are at least 8 mm apart 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 in the ejector and core ( 1 ) are admitted.

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 on the core ( 1 ) with two mounting holes and two ventilation / impression holes. It is particularly preferred if the tool gap dimensions between the lower and upper tool and between stamp ( 4 ) as well as fold holders ( 2 ) and core ( 1 ) of 20 to 40 microns. 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 if the production is carried out on a tool with throughputs of at least 150, more preferably at least 190, pieces / min. 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 (11)

Lacquered, printed and embossed deep-drawn, in the supervision circular Lid made of aluminum, essentially in the form of a one-sided open Cylinder in which the printing on the substantially flat area has at least one contour, which also represents the contour of the embossing available through a sequence of concluding 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) if necessary edge rolling, wherein steps (b), (c), (d) and optionally (e) be performed with a single tool. Process for the production of printed and embossed deep-drawn, in plan view, circular aluminum cover characterized by a Sequence of subsequent 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 edge rolling, wherein steps (b) , (c), (d) and, if applicable, (e) be carried out with a single tool. 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 not more than 0.3 mm. 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 a punch ( 4 ) and an ejector ( 5 ) and the ejector has an embossing tool in the region of its center, ventilation and fastening bores outside the embossing tool and an annular clamping region ( 6 ), the edges of which are at least 8 mm apart 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 in the ejector and core ( 1 ) are admitted. Lid or method according to one of the preceding claims characterized in that the method steps (b) pruning the aluminum panel 135 to 145 ° after OT, (c) deep drawing 140 to 170 ° after OT (d) embossing 170 to 180 ° after OT, (e) Randollung if necessary 180 to 200 ° after TDC and (f) if necessary blow out 330 to 360 ° after OT take place, in each case based on the position of the driving Crankshaft. Lid or method according to one of the preceding claims, characterized in that the embossing tool on the core ( 1 ) with two mounting holes and two ventilation / impression holes. Lid or method according to one of the preceding claims, characterized in that the tool gap dimensions between the lower and upper tool and between stamp ( 4 ) as well as fold holders ( 2 ) and core ( 1 ) of 20 to 40 microns. Lid or method according to one of the preceding claims characterized in that the tool has an ejector, the across from later Lid shape towards the open side of the lid with at least 50% its surface is arranged counter to 0.4 to 0.9 mm. Lid or method according to one of the preceding claims characterized in that the manufacture on a tool with throughputs of at least 150, more preferably at least 190, pieces / min. Lid or method according to one of the preceding claims characterized in that the lid is made of an AlMg alloy with 2.5% Mg. Dose containing a cosmetic preparation thereby characterized in that it has a lid according to one of the preceding Claims.