EP2448765B1 - Method and device for producing construction elements - Google Patents

Description

The invention relates to a method for producing exposed to weathering components, such as metallic components, in particular Sektionaltorpaneelen, Rolltorlamellen o. The like.

In many cases, metallic components are used in the façade of buildings. For example, such components are used in the manufacture of gates, in particular sectional doors, the outer boundary surface is exposed to weather conditions in the closed state. In order to obtain a pleasing appearance, care must be taken to ensure that these components retain their optical properties even under the effects of the weather. For this purpose, today components are used, which are made of a metal sheet, which is subjected before the necessary to obtain the components forming processes a painting and firing. The lacquer is thus baked on the metallic substrate and obtained in this way the desired weather resistance. The thus prepared metal sheet is then subjected to a forming operation such as a roll forming process to obtain structural members such as sectional metallic panels in which the painted metal sheet is withdrawn from a supply (coil) and continuously passes through forming rollers. Thereafter, the shaped metal sheet is possibly still filled with foam and joined together with other metal sheets, for example in the EP 370 376 A to get described Sektionaltorpaneele. The painting process must be carried out so that no damage to the paint surface occurs during the molding process. Optionally, it is also necessary that the painted sheets survive an embossing operation unscathed, which precedes the molding process and with the example, a "wood grain embossing" of the metal sheet is obtained. Other methods of printing on metal bands are

documents EP 2 011 660 A1 such as US 2002/090456 A1 refer to.

Components usually need to be provided with different colors and designs. Therefore, different supplies of appropriately pretreated metal sheets must be provided. For some design wishes, it is also necessary to apply films to the possibly pretreated metal sheet and these films u. U. also still cover to obtain the desired weather resistance with a protective film. This is the case, for example, if the metallic components are to receive a wood decor. In this case, a film with wood decor is applied to the metallic substrate and then laminated an acrylate film on the decorative film. The acrylate film may have a thickness of about 50 microns. Again, appropriately prepared sheet metal supplies (coils) must be provided for each decor. This brings significant storage problems with it. In view of these problems in the prior art, the invention has for its object to provide methods for producing exposed to weathering components, in particular Sektionaltorpaneelen, with which components can be provided with the desired external appearance without excessive effort for the storage, to provide corresponding components and a device to provide for performing appropriate procedures.

According to the invention, this object is achieved by a refinement of the known method, which is characterized essentially by the fact that already formed and possibly provided with a base coating components are printed.

The invention is based on the realization that it is not necessary to obtain the desired appearance before the processing, such as shaping, embossing o. The like to obtain the desired appearance appearance, the desired decoration before editing. Rather, it is sufficient if the desired decor is applied only when the molding process is completed. Therefore, devices of any external appearance can be manufactured using one and the same source material so as to simplify the overall storage.

The printing process can be computer-controlled on the basis of digital image data. Therefore, any desired customer-specific external appearance of the components can be obtained with the method according to the invention. Customer-supplied image data, such as JPG files, may also be used. Therefore, using inventive method not only simplifies the storage but also increases the variability of the manufacturing process. In this case, the pressure at the end of a production line for the continuous production of components after shaping and possibly foaming of the components, but even before cutting the components to the desired length can be done.

In a preferred embodiment of the invention, the printing of the device surface by means of a printing device in the manner of an ink jet printer, wherein a relative movement between the surface to be printed of the device and a print head is generated, in the course of at least one for spraying a paint on the device surface designed ink jet the print head passes the surface to be printed. In this way, for example, using a simple printhead when using metal sheets with the usual white stoving as the starting material any black and white motifs can be generated on the device surfaces. It is then only black color used. In order to obtain colored representations on the component surfaces, it has proved to be advantageous if, in the course of the relative movement, two, three or more ink nozzles of the print head pass, if appropriate, one after the other the surface to be printed. By appropriate adjustment and possibly computer-aided control of the ink nozzles so motifs of any shape and color can be generated on the device surfaces. As with conventional inkjet printers, the three primary colors cyan, magenta and yellow and optionally light magenta and light cyan can be used to obtain any desired colors by means of subtractive mixing.

To generate the relative movement between the component on the one hand and the printhead or the printheads on the other hand, the printheads with respect to a while moving the component in a direction perpendicular to the reciprocating motion with respect to the printheads and the frame. In a particularly preferred embodiment of the invention, the printhead or the printheads is arranged fixed relative to the frame, wherein the relative movement takes place exclusively by movement of the component with respect to the ink nozzles. The ink nozzles are then driven in response to the advancing movement of the components for printing the components with the mixed motifs. For this purpose, computer-controlled printing systems can be used.

In particular, UV-curable inks can be used as inks for the printing process. These colors are cured immediately after being sprayed or applied in a radiation curing process under irradiation with UV radiation. In this chemical curing, the initially liquid or low-viscosity color is determined by crosslinking or polymerization in an irreversible process. This curing process can be completed within fractions of a second with sufficiently intense UV irradiation. For this purpose, the printhead preferably comprises a device for providing the UV radiation, so that curing of the ink can take place immediately after spraying. Due to the rapid curing, the printing speed and thus the throughput speed of the components can be increased. Furthermore, a subsequent directly to the printing process further coating is possible because no longer drying times of the color are to be seen.

UV-curable inks are usually not suitable for outdoor use because they are not very weather-resistant. However, it must be ensured that the external appearance of the components obtained by printing is also resistant to weathering. For this purpose, the printed surface of the component is preferably additionally provided with a weather-resistant coating. In a particularly preferred embodiment of the invention, the weather-resistant coating is applied only after a pre-curing of the paint. It has been recognized that the application of a weather-resistant coating on printed substrates exerts no appreciable influence on the external appearance obtained by the printing process, with possible minor influences can be compensated by appropriate modification of the printing process.

The weather-resistant coating can be formed, for example, in the form of a weather-resistant, preferably transparent special ink or in the form of a liquid, substantially transparent clearcoat.

After printing, the resulting appearance of the device can be preserved when the weather-resistant coating is sprayed onto the printed surface via a preferably having a nozzle diameter of 50 microns or less, in particular 35 microns or less coating die. In this case, a relative movement between the printed surface and the coating nozzle can also be generated for spraying the weather-resistant coating. This relative movement is also preferably generated by a movement of the components with respect to a fixed frame in the printing device, wherein the coating nozzles are arranged fixed with respect to the frame. In this case, preferably, a plurality of coating nozzles extend in a direction perpendicular to the direction of movement of the components, so that the entire surface of the components can be provided by a simple advancing movement of the components with the weather-resistant coating.

In a particularly preferred embodiment of the invention, a common relative movement of the print head and the coating nozzle, with respect to the component surface, in particular generated by the advancing movement of the components, in the course of the coating nozzle printed surface areas passes to the paint nozzles. This can be done, for example, by additionally providing the printhead with the coating nozzle, wherein the coating nozzle is assigned a storage container for the coating material. Ink nozzles and coating nozzles can then be moved together. In the described preferred embodiment of the invention with a fixed printhead, the coating nozzle or nozzles is designed as an independent component.

In the course of the printing process, a reciprocating movement of the inking nozzles with respect to the surface to be coated can also be produced, the surface to be coated being conveyed in a direction perpendicular to the direction of movement of the inking nozzles with respect to the inking nozzles. In this case, it has proved to be particularly useful if at least one coating nozzle is provided on each side of the paint nozzles. Then the printing process with subsequent coating in each direction of movement so carried out that the first applied the color and the printed surface is coated immediately thereafter with the coating material. As a result, the manufacturing process can be significantly accelerated.

It has been found that in manufacturing processes for conventional sectional door panels having a width of 400 mm or more transversely to the production direction, a production speed of 10 m / minute or more, preferably 15 m / minute or more, in particular 20 m / minute or more can be obtained if the components for printing and coating pass through a coating system having at least one print head and at least one coating nozzle at a corresponding throughput speed. To increase the production speed, the coating installation can have two, three or more print heads arranged side by side in a transversely extending printing direction with corresponding coating nozzles, so that only a narrow surface area of each print head has to be coated. Then, the coating method can be performed with fixed printheads. The method according to the invention has also proved to be favorable with regard to a material saving that can be achieved thereby, since it is sufficient if the ink is applied during printing with a total thickness of only 15 μm or less, preferably 10 μm or less, in particular 5 μm or less wherein the desired weatherability can be obtained, even if the weather-resistant coating with a total layer thickness of only 15 microns or less, preferably 10 microns or less, in particular 5 microns or less is applied. Overall, the total thickness of paint and coating material can be 30 μm or less.

As can be seen from the above explanation, the method according to the invention can be integrated into a continuous process for the production of metallic components, in which a metal strip optionally provided with a base coating is stripped from a supply (coil) in a continuous process about a shape, foaming o. The like. Subjected, printed, coated and possibly cut to a predetermined length.

A component obtained by the method according to the invention is essentially characterized in that it has a printed surface area, which can additionally be provided with a weather-resistant coating.

In particular, in so-called sandwich components, in which a heat-insulating core is accommodated between two metal shells, it has proved to be problematic when a dark colored outer boundary surface of the component is exposed to solar radiation and thereby warms up, because by the temperature difference between the outer boundary surface and inner boundary surface thermal stresses are generated in the device, which can lead to bending of the device. This effect can be reduced if the base coat, the paint and / or the weather-resistant coating pigments with a particularly high reflectivity in the wavelength range above 750 nm, because then a large part of the otherwise absorbed and leading to the heating of the components heat radiation in the solar spectrum not absorbed but reflected without warming effect. When using corresponding cool color pigments, it has proved to be particularly useful if the average reflectivity (ratio of reflected intensity to incident intensity) of the coated device surface for electromagnetic waves in the wavelength range of 750 nm to 2500 nm at an angle of incidence of 45 ° 0.1 or more, preferably 0.2 or more, in particular 0.25 or more.

As can be seen from the above explanation, the cool color pigments mentioned are used to particular advantage when the component has a material of low thermal conductivity, such as PU foam, between the printed surface and an opposing boundary surface. A sectional door panel produced from components according to the invention has a plurality of components articulated to each other with respect to predetermined hinge axes, the shape of the components being in a sectional plane perpendicular to the hinge axes of the form shown in FIG EP 370 376 A can correspond to sectional overhead panels described.

In a sectional door according to the invention the sectional door leaf between a substantially aligned in a vertical plane closed position and a substantially aligned in a horizontal plane open position is movable. To the sectional door in addition to the Sektionaltorblatt guide rails with a first approximately in the direction of gravity and rectilinear portion for determining the closed position, a second, approximately horizontally and rectilinearly extending portion for determining the open position and the horizontal portion extending to the vertical section connecting arcuate section on. In addition, the sectional door may also comprise a section which encloses the sectional door leaf in the closed position, gff in the sectional door leaf. even a wicket door can be integrated.

A coating system according to the invention for carrying out a method according to the invention has at least one printing head designed for printing on a surface of a metallic component, which may already be provided with a base coat, and preferably additionally a coating device, in particular a coating die, designed to coat the printed surface with a weather-resistant coating. In this case, the coating device may comprise a reservoir containing the coating material and associated with the coating nozzle. In order to obtain desired processing properties, the coating material may include a solvent such as mehoxypropanol, isopropyl alcohol or the like for adjusting the viscosity of the coating material to a desired value. The solvent is volatile in air, so that it does not affect the properties of the coating after completion of the coating process.

The coating material can be applied with coating nozzles in the form of color nozzles of conventional inkjet printers if the viscosity of the coating material is adjusted to a value of 50 mPas or less, in particular 10 mPas or less, particularly preferably 5 mPas. The coating material used is in particular a weather-resistant, preferably transparent special ink or clearcoat. In addition to a particularly good weathering resistance, the clearcoat can also have a high scratch resistance and provide very good UV resistance. It can be applied with a coverage of 6 to 7 microns and cured after the coating process under the influence of UV light. It has proved to be useful if the components to be coated are arranged with running in the direction of gravity printed surface and the clear coat or ink is applied from the top of the correspondingly aligned device from a nozzle out. Under the influence of gravity, the clearcoat or the distributed Ink over the printed component surface and may optionally be subsequently UV cured.

The invention will be explained with reference to the drawing, to which reference is expressly made with respect to all essential to the invention and in the description unspecified highlighted details. The sole figure of the drawing shows a schematic representation of a coating system according to the invention.

In the coating system shown in the drawing, a received by a shaping operation, but not cut to predetermined lengths component 10, which is indicated only schematically in the drawing, continuously conveyed in the direction indicated by the arrow P direction below a generally designated 20 printhead wherein the print head is reciprocally movable in the directions indicated by the double-headed arrow DP perpendicular to the conveying direction P. The printhead 20 includes two coating nozzles 22 and 24, each of which is adapted to apply a weather resistant coating to the surface of the component 10, and a total of three ink nozzles 25, 26 and 27, each of which is designed to print the component with one color each , The coating nozzles 22 and 24 are driven so that only one of them is used to coat the material area printed with the printing nozzles 25, 26 and / or 27 after this material area has been printed. Devices for generating UV radiation can be arranged between ink nozzles and coating nozzles. The printing nozzles are controlled in accordance with a color print via a computer so that the surface of the component 10 is printed with desired, for example, by custom image data predetermined subjects. In this way, the device surfaces can be provided with any motifs.

The invention is not limited to the embodiment illustrated with reference to the drawing. Rather, it is also thought to arrange two, three or more printheads in a direction transverse to the conveying direction P side by side to reduce the printing area for each printhead and to increase the overall production speed can. Furthermore, methods according to the invention can be used not only for printing on metallic components, but also for printing components made of other materials, such as plastics.

Claims (12)

1. A method for producing metallic structural elements exposed to the effects of weather in the form of sectional door panels or roll-up door slats or the like, wherein a metal strip is pulled off of a coil in a continuous process, is subjected to forming wherein it runs continuously through forming rollers and is optionally cut to specified lengths, characterised in that the metal strip is imprinted after forming.
2. The method according to Claim 1, characterised in that for the purpose of imprinting a relative motion is created between the surface of the structural element to be imprinted and a print head, during the course of which at least one ink nozzle of the print head designed for spraying an ink onto the structural element surface passes the surface to be imprinted.
3. The method according to Claim 2, characterised in that during the course of the relative motion, two, three or more ink nozzles of the print head pass the surface to be imprinted in sequence.
4. The method according to Claim 2 or 3, characterised in that the ink is cured after the printing process, in particular with the aid of UV radiation.
5. The method according to Claim 4, characterised in that the print head includes a device for providing the UV rays so that the ink cures immediately after it is sprayed on.
6. The method according to any of the preceding claims, characterised in that at least one imprinted surface area of the structural elements is provided with a weather-resistant coating, such as for example a weather-resistant special ink or a substantially transparent clear varnish that can be applied in liquid form, in particular after the curing of the ink.
7. The method according to Claim 6, characterised in that the weather-resistant coating is sprayed onto the imprinted surface with a coating nozzle preferably having a nozzle diameter of 50 µm or less, in particular 35 µm or less.
8. The method according to Claim 7, characterised in that for spraying on the weather-resistant coating a relative motion between the imprinted surface and the coating nozzle is created.
9. The method according to Claim 7 or 8, characterised in that a common relative movement of the print head and the coating nozzle relative to the structural element surface is created, during the course of which the coating nozzle passes the imprinted surface areas after the ink nozzles.
10. The method according to any of the preceding claims, characterised in that during the imprinting, ink with a layer thickness of a total of 15 µm or less, preferably 10 µm or less, in particular 5 µm or less is applied.
11. The method according to any of Claims 6 to 10, characterised in that the weather-resistant coating is applied with an overall layer thickness of 15 µm or less, preferably 10 µm or less, in particular 5 µm or less.
12. The method according to any of the preceding claims, characterised in that the structural elements for imprinting and coating pass through a coating unit having at least one print head and at least one coating nozzle with a throughput speed of preferably 10 m/minute or more, in particular 15 m/minute or more, particularly preferably 20 m/minute or more.

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