Machine for manufacturing three-part cans formed from sheet metal parts

Abstract

Machine for manufacturing three-part cans formed from sheet metal parts, with several processing stations (02; 03; 04; 05; 06; 07; 08; 10; 11; 12; 13) arranged in succession for processing at least one of the sheet metal parts forming the respective three-part can and comprising at least one first transport device (01) and a second transport device (09), wherein the first transport device (01) is configured to transport at least one of the sheet metal parts forming the respective three-part can, wherein the second transport device (09) is configured to transport this sheet metal part to a bending device (10) forming a can body and / or a welding device (11) or a soldering device (12) or a flanging device (13), wherein a pretreatment device (02) is provided.wherein this pretreatment device (02) is configured to prepare a surface of the sheet metal part to be decorated for the receipt of a UV-curing lacquer, wherein at least one printing device (05) is provided, wherein this printing device (05) is configured to apply a printing ink or ink to the surface of the sheet metal part used to manufacture the respective three-part can, characterized in that this machine is configured to process sheet metal parts formed from a sheet metal panel or from a sheet metal strip by means of a punching device or a cutting device, wherein the first transport device (01) and / or the second transport device (09) is / are each configured as a belt transport system or to transport the sheet metal part in question on rollers,wherein the relevant first transport device (01) is designed to feed the sheet metal part to be decorated with its unpainted and / or unprinted side facing upwards onto the belt transport system or onto the rollers transporting the relevant sheet metal part, in each case lying flat on the belt transport system or onto the rollers transporting the relevant sheet metal part, to the pretreatment device (02), wherein the at least one pressure device (05) is arranged in the transport path between the first transport device (01) and the second transport device (09).

Description

[0001] The invention relates to a machine for manufacturing three-part cans formed from sheet metal parts according to the preamble of claim 1.

[0002] Cans are a packaging medium used to make goods, i.e., a product to be packaged, transportable. Furthermore, cans serve, for example, the purpose of long-term storage of perishable goods, such as food. They are made of sheet metal, particularly tinplate or aluminum. After being filled with the product, cans are sealed at their opening by soldering and / or crimping. Unlike beverage cans, which are preferably made of aluminum as two-piece cans, cans are made of three parts and consist of a can body—the so-called rim—with a longitudinal seam that is usually welded. This can body may preferably be corrugated for reinforcement. The rim of a can is the lateral component that surrounds the product, i.e., the contents of the can.Thus, three-piece tin cans consist at least of a tubular can body, i.e., the rim, which is welded or crimped along the longitudinal seam and possibly additionally soldered, and two lids arranged at the ends of the can body, i.e., a total of three joined sheet metal parts. In contrast, beverage cans designed as so-called two-piece cans typically consist of a circular bottom and a preferably straight cylindrical shell, each made from a single workpiece, i.e., a so-called slug or a blank, i.e., a circular disc, in a forming process, e.g., a cold extrusion process or a tensile-compression forming process, preferably by deep drawing, in particular by stretch drawing, to form a hollow body open at one end, i.e., a so-called raw can.In the case of two-part cans, a circular lid is placed on the cylinder shell in a manufacturing step carried out at the end of production and is hermetically sealed to the cylinder shell by crimping.

[0003] Especially in larger production runs, i.e., quantities of, for example, several tens of thousands of cans, varnishing, printing, or embossing on at least one exterior surface of each can is currently applied to the base material, consisting of a sheet or strip of metal, before the actual can manufacturing process. This is done, for example, using offset or inkjet printing. As a rule, this means that at least three layers are applied to at least one of the metal parts: 1) a base coat to enable the application of the printed image, 2) the actual printed image, and 3) a protective varnish to shield the printed image from external influences.This decoration of each can is carried out before the actual can production using several machine passes in a coating machine and a printing press, separate from a machine for welding the longitudinal edges of rounded can sides. A disadvantage of this approach is that each machine pass involves setup, storage, and / or processing times. Therefore, this method is not practical for the economical production of small runs of, for example, a few thousand cans. Furthermore, the required setup, storage, and / or processing times practically preclude short delivery times, as the machine passes in the coating and / or printing press must be customized for each order, since the coated area and the printed image always depend on the specific customer order.The procedure known from practice means that three-part cans, especially three-part tin cans, can only be manufactured after the sheet metal parts used as the starting material have been decorated.

[0004] DE 35 30 781 A1 discloses a machine for welding longitudinal edges of rounded can bodies.

[0005] CH 702 885 A2 and US 2013 / 0048653 A1, belonging to the same patent family, each disclose a device for manufacturing a can body with a can shell and a can bottom, which device comprises a feed device, a cutting device, and a first and a second laser welding device, wherein the metal strip is moved by the feed device in the longitudinal direction of the metal strip against the cutting device, cutting steps are performed by the cutting device to provide sections of the metal strip as can shells with a butted laser longitudinal seam produced by the first laser welding device, and joining steps are performed by the second laser welding device by which a can bottom is attached to an end face of each can shell, wherein the device comprises a printing device with which the metal strip is printed with decorative surfaces and longitudinal register marks in a printing step.wherein the decorative surfaces in a first direction of the metal strip, preferably in its longitudinal direction, have a height extension of the can decoration in the direction of the can axis and transversely to the first direction the circumferential extension of the can decoration, the longitudinal register marks are arranged in the area of ​​the decorative surfaces and enable the control of the separation steps in such a way that the separated can shells each comprise a complete decorative surface.

[0006] DE 10 2017 112 198 A1 discloses a device for producing a printed can lid using a digital printing process, wherein a raw lid has an outer surface and an inner surface; wherein the device comprises at least: (1) a control unit for processing the print image; (2) a conveying unit for transporting the raw lid along a conveying direction; (3) a first digital printing unit with at least one printhead with which the print image provided by the control unit can be printed onto the outer surface.

[0007] JP 2021-011084 A discloses a printing process for printing several types of designs on the main surface of a metal plate as a combination plate, wherein the several types of designs are combined to form a printing plate; and cutting the printing plate into parts to form a blank for a can body; a cutting step for forming a can body by rolling the blank into a cylindrical shape so that both end edges of the blank touch each other, and welding the two end edges together, and forming a can body by attaching a bottom to an opening of the can body.

[0008] The invention is based on the objective of creating a machine for manufacturing three-part cans formed from sheet metal parts, which is also suitable for the production of externally decorated tin cans in small batches down to very small batches.

[0009] The problem is solved according to the invention by the features of claim 1. The dependent claims relate to advantageous embodiments and / or further developments of the solution found.

[0010] The advantages achievable with the invention lie particularly in the fact that even small production runs, down to very small runs of tin cans, can be decorated in a customer-specific manner in an economical way. Further advantages are evident from the following embodiment.

[0011] An embodiment of the invention is shown in the single drawing and is described in more detail below.

[0012] Fig. Figure 1 shows a simplified block diagram of a machine for manufacturing three-part cans made from sheet metal parts. This machine is described in the... Fig.The machine shown in the frame has at least one first transport device 01, wherein the first transport device 01 is designed such that it transports at least one of the sheet metal parts forming the three-part can, e.g., the sheet metal part that later forms the can body, lying flat, e.g., on at least one belt or on rollers. Downstream of the first transport device 01, this machine has several processing stations 02; 03; 04; 05; 06; 07; 08; 10; 11; 12; 13 successively along a transport path comprising several sections, in a transport direction of the sheet metal part indicated by directional arrows, wherein these processing stations 02; 03; 04; 05; 06; 07; 08; 10; 11; 12; 13 are now described below. The processing of sheet metal parts takes place directly in this machine in several successive processing steps, i.e.also inline, and includes all processing steps required for the production of three-part cans, from the feeding of the starting material, in particular sheet metal parts formed from e.g. a sheet of metal or from a strip of metal, e.g. by means of a punching device or a cutting device, to the finished three-part can, preferably designed as a tin can.

[0013] The first transport device 01 conveys a sheet metal part to be decorated, with its unpainted and / or unprinted side facing upwards, e.g., lying flat on a belt transport system, to a pretreatment device 02, wherein this pretreatment device 02 is designed to prepare the surface of the sheet metal part to be decorated for the application of a UV-curing coating. This preparation consists, for example, of plasma pretreatment, IR treatment, or flame treatment of the surface of this component.

[0014] After pretreatment, a UV-curing primer is applied to the surface of the sheet metal part to be decorated in a first coating unit 03. This is done, for example, using a roller system, in particular a system comprising an anilox roller, or by using a digital coating process. After this primer coating, the coating layer is cured by means of a first radiation unit 04 emitting UV radiation, wherein this first radiation unit 04 is, for example, designed as an LED radiation unit.

[0015] Typically, after a preliminary coat of paint, a UV-curing printing ink or ink is applied to the basecoated surface of the sheet metal part to be decorated in a printing unit 05 to create a printed image, usually a customer-specific design. This is done, for example, using a roller system or a digital printing process. The printing ink or ink is then cured by a second radiation unit 06, which emits UV radiation and is itself, for example, an LED radiation unit.

[0016] After the printed image has been formed, a protective varnish is preferably applied to it in a second coating unit 07. This is also done, for example, by means of a roller system, in particular a system comprising an anilox roller, or by using a digital coating process. After the protective varnish has been applied, the varnish layer is cured by means of a third radiation unit 08 emitting UV radiation, wherein this third radiation unit 08 is, for example, designed as an LED radiation unit.

[0017] The sheet metal part decorated in this way is then fed by means of a second transport device 09, e.g. designed as a belt transport system, to a bending device 10 which forms this sheet metal part into a can body and then, e.g., to a welding device 11 or a soldering device 12 or a flanging device 13 which connects two opposing longitudinal edges of the sheet metal part forming the can body.

[0018] In summary, a machine for manufacturing three-part cans formed from sheet metal parts is provided, comprising several processing stations 02; 03; 04; 05; 06; 07; 08; 10; 11; 12; 13 arranged in succession for processing at least one of the sheet metal parts forming the respective three-part can and comprising at least one first transport device 01 and a second transport device 09, wherein the first transport device 01 is designed such that it transports at least one of the sheet metal parts forming the respective three-part can in a flat position, and wherein the second transport device 09 is designed such that it transports this sheet metal part to a bending device 10 forming a can body and / or a welding device 11 or a soldering device 12 or a flanging device 13.According to the invention, at least one printing device 05 is arranged in the transport path between the first transport device 01 and the second transport device 09, wherein this printing device 05 is configured to apply a printing ink, in particular a UV-curing ink, to the surface of the sheet metal part used to manufacture the respective three-part can. Preferably, a pretreatment device 02 is arranged in the transport path between the first transport device 01 and the printing device 05, wherein this pretreatment device 02 is configured to pretreat an unpainted and / or unprinted side of the sheet metal part used to manufacture the respective three-part can by plasma pretreatment, IR treatment, or flame treatment of the surface of this component.A first coating unit 03 is preferably arranged in the transport path between the pretreatment unit 02 and the printing unit 05. This first coating unit 03 is configured to apply a UV-curing primer to the surface of the sheet metal part treated in the pretreatment unit 02. Furthermore, a first radiation unit 04 emitting UV radiation is preferably arranged in the transport path between the first coating unit 03 and the printing unit 05. A second radiation unit 06 emitting UV radiation is preferably arranged directly downstream of the printing unit 05 in the transport path between the printing unit 05 and the second transport unit 09.A second coating unit 07 is preferably arranged in the transport path between the printing unit 05 and the second transport unit 09, wherein this second coating unit 07 is designed to apply a UV-curing protective coating at least to the surface of the sheet metal part printed in the printing unit 05. A third radiation unit 08, emitting UV radiation, is then preferably arranged in the transport path between the second coating unit 07 and the second transport unit 09.

[0019] The first transport device 01 and / or the second transport device 09 are each preferably designed as a belt transport system or transporting the sheet metal part in question on rollers. The first painting device 03 and / or the second painting device 07 are each preferably designed to apply their respective paint by means of a roller system, in particular a system comprising an anilox roller, or by using a digital painting process. The first radiation unit 04 and / or the second radiation unit 06 and / or the third radiation unit 08 are each preferably designed as an LED radiation unit.

[0020] The pretreatment device 02 or the first painting device 03 or the first blasting unit 04 or the pressure device 05 or the second blasting unit 06 or the second painting device 07 or the third blasting unit 08 or the bending device 10 or the welding device 11 or the soldering device 12 or the flanging device 13 each form one of the processing stations 02; 03; 04; 05; 06; 07; 08; 10; 11; 12; 13 of the proposed machine for manufacturing three-part cans formed from sheet metal parts.

[0021] The advantage of the solution found is in particular that by integrating at least one of the devices 02; 03; 04; 05; 06; 07; 08 decorating the three-part cans into the machine for manufacturing three-part cans formed from sheet metal parts, even small batches down to very small batches of three-part cans, preferably designed as tin cans, can be produced economically and in a customer-specific manner. Reference symbol list 01 first transport device 02 Pre-treatment facility 03 first painting facility 04 first radiation unit 05 Printing device 06 second radiation unit 07 second painting facility 08 third radiation unit 09 second transport facility 10 Bending device 11 Welding equipment 12 Soldering equipment 13 Flaring device

Claims

[1] Machine for manufacturing three-part cans formed from sheet metal parts, with several processing stations (02; 03; 04; 05; 06; 07; 08; 10; 11; 12; 13) arranged in succession for processing at least one of the sheet metal parts forming the respective three-part can and comprising at least one first transport device (01) and a second transport device (09), wherein the first transport device (01) is configured to transport at least one of the sheet metal parts forming the respective three-part can, wherein the second transport device (09) is configured to transport this sheet metal part to a bending device (10) forming a can body and / or a welding device (11) or a soldering device (12) or a flanging device (13), wherein a pretreatment device (02) is provided,wherein this pretreatment device (02) is configured to prepare a surface of the sheet metal part to be decorated for the receipt of a UV-curing varnish, wherein at least one printing device (05) is provided, wherein this printing device (05) is configured to apply a printing ink or ink to the surface of the sheet metal part used to manufacture the respective three-part can, characterized bythat this machine is designed to process sheet metal parts formed from a sheet of metal or from a strip of sheet metal by means of a punching device or a cutting device, wherein the first transport device (01) and / or the second transport device (09) is / are each designed as a belt transport system or transporting the sheet metal part in question on rollers, wherein the first transport device (01) is designed to feed the sheet metal part to be decorated with its unpainted and / or unprinted side facing upwards onto the belt transport system or onto the rollers transporting the sheet metal part in question, in each case lying flat on the pretreatment device (02), wherein the at least one pressure device (05) is arranged in the transport path between the first transport device (01) and the second transport device (09). [2] Machine according to claim 1, characterized by, that the pretreatment device (02) is designed such that it pretreats the unpainted and / or unprinted side of the sheet metal part used to manufacture the respective three-part can by plasma pretreatment or by IR treatment or by flame treatment of the surface of this component. [3] Machine according to claim 2, characterized by , that a first painting device (03) is arranged in the transport path between the pretreatment device (02) and the printing device (05), wherein this first painting device (03) is designed to apply a UV-curing primer to the surface of the sheet metal part treated in the pretreatment device (02). [4] Machine according to claim 3, characterized by , that a first radiation unit (04) emitting UV radiation is arranged in the transport path between the first painting device (03) and the printing device (05). [5] Machine according to claim 1 or 2 or 3 or 4, characterized by , that in the transport path between the pressure device (05) and the second transport device (09) of the pressure device (05) a second radiation unit (06) emitting radiation is arranged immediately downstream. [6] Machine according to claim 1 or 2 or 3 or 4 or 5, characterized by , that a second coating device (07) is arranged in the transport path between the printing device (05) and the second transport device (09), wherein this second coating device (07) is designed in such a way that it is designed to apply a UV-curing protective coating at least to the surface of the sheet metal part printed in the printing device (05). [7] Machine according to claim 6, characterized by , that a third radiation unit (08) emitting UV radiation is arranged in the transport path between the second painting device (07) and the second transport device (09). [8] Machine according to claim 3 or 4 or 5 or 6 or 7, characterized by that the first painting unit (03) and / or the second painting unit (07) are designed to apply their respective paint by means of a roller system or a system having an anilox roller or by using a digital painting process. [9] Machine according to claim 4 or 5 or 6 or 7 or 8, characterized by , that the first radiation unit (04) and / or the second radiation unit (06) and / or the third radiation unit (08) are each designed as an LED radiation unit.

Images