Method for processing a structured surface of an embossing tool

Abstract

The invention relates to a method for processing a structured surface of an embossing tool, in which the entire surface is provided with a first metallic coating and said surface having, in selected regions, at least one additional metallic coating that has a differing degree of lustre. To improve the optical properties of the material boards produced using the embossing tools, particularly if reproducing a wood texture, the invention suggests that additional differing degrees of lustre should be produced in multiple selected regions on the first coating, and be produced by a combination of metallic coatings and mechanical or chemical after-treatments. Therefore, for example, a wood pore with a defined structure can be substantially better reproduced, and the optical and haptic properties of the wood composite board produced using the press plates can thus be improved.

Claims

1. A method for processing a surface of an embossing tool, in which at least one surface is subjected to a first treatment step in the form of a metallic coating, a mechanical gloss-changing treatment or a chemical treatment over the entire area to achieve a degree of gloss and there is at least one further step in selected areas (7, 8, 9, 10, 11) to achieve at least one further different degree of gloss, characterized in that the at least one further different degree of gloss is obtained in several selected areas (7, 8, 9, 10, 11) on the surface with the first degree of gloss, wherein the at least one further degree of gloss is obtained via a metallic coating, mechanical follow-up treatment or chemical follow-up treatment, wherein a protective layer is at least partially applied to the surface by means of a digital printing technique to establish the selected areas (7, 8, 9, 10, 11), and wherein the protective layer is applied in a partially overlapping form with respect to the areas that have already been completed.

2. A method according to claim 1, characterized in that the further degrees of gloss of the surface have at least partially a spacing between them.

3. A method according to claim 1, characterized in that a material that is resistant to etching, sandblasting or polishing is used for the protective layer.

4. A method according to claim 1, characterized in that a chromium coating is applied to the surface or the further degrees of gloss of the surface are obtained by etching or sandblasting.

5. A method according to claim 1, characterized in that the further degrees of gloss of the surface are obtained by mechanical polishing or electropolishing.

6. A method according to claim 1, characterized in that the surface is activated before the first treatment step or a chromium plating is applied to the surface after the production of the last further degree of gloss.

7. A method for processing a surface of an embossing tool, in which at least one surface is subjected to a first treatment step in the form of a metallic coating or a chemical treatment over the entire area to achieve a degree of gloss and there is at least one further step in selected areas to achieve at least one further different degree of gloss, characterized in that the at least one further different degree of gloss is obtained in several selected areas on the surface with the first degree of gloss, wherein the at least one further degree of gloss is obtained via a metallic coating, mechanical follow-up treatment or chemical follow-up treatment and wherein a protective layer is applied in a partially overlapping form with respect to the areas that have already been completed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be explained once again below with the aid of the figures.

(2) FIG. 1 shows a pressed sheet in accordance with the invention in a perspective view and

(3) FIG. 2 shows the existing structure on the surface of the pressed sheet with different degrees of gloss in an enlarged side view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(4) FIG. 1 shows, in a perspective view, a pressed sheet 1 in accordance with the invention that is designed to be flat in the example that is shown. This embossing tool can also be designed to be curved in the case of an endless sheet, however. The pressed sheet 1 shows a grain 2 that is replicated in the form of a wood structure. It is conceivable, however, that other kinds of grain or other surface characteristics of this type can be created with the process in accordance with the invention and the etching process that is required for that.

(5) FIG. 2 shows, in an enlarged side view, a portion of the front edge area of the pressed sheet 1 and the structure 3 found on it, which has a surface resembling mountains with valleys 4 and peaks 5. The surface is created by one or more etching processes in connection with this, after the previous application of a matrix in a standard process or with a digitalized printing technique; the areas that are not supposed to be subjected to the etching processes are covered by the mask. Fine surface structures and deep structures that are additionally rounded off via mechanical processes or etching processes if necessary after that, as examples, can be created with the aid of the etching processes. After the surface is etched, the surface structure is finished off with further chemical processing, polishing and, if applicable, activation of the polished surface, so cleaning is subsequently done before an initial metallic coating 6 is applied with a certain degree of gloss.

(6) The metallic coating 6 has a certain degree of gloss that is in line with the customer's requests. A mask is subsequently applied once again to this first metallic coating 6 that covers the areas that are not supposed to be subjected to any further treatment.

(7) The exposed areas can, on the other hand, be provided with a different degree of gloss via further processing techniques and, in fact, via matte etching, sandblasting or mechanical polishing or another application of a metallic coating, for instance.

(8) The process in accordance with the invention provides here for a mask to be applied for certain partial areas in each case and for the exposed areas to be subjected to a further treatment process. This process can be repeated several times after the applied mask is removed, so the structure 3 of the pressed sheet 1 will get differing degrees of gloss in selected areas.

(9) Various degrees of gloss arose on the first metallic coating 6 via the application of different masks and subsequent treatment processes in the example that was shown. There was no treatment in the area of the valleys 4, for instance, so the areas 7 indicated in white have the degree of gloss of the first metallic coating 6, whereas, in contrast, the tips of the peaks 5 have degrees of gloss differing from that. These differing degrees of gloss are indicated by the areas 8 completely colored in and by the hatched areas 9 and 10. A degree of gloss deviating from that arose via a subsequent process step by applying a corresponding mask in the transition areas of the valleys 4 and peaks 5. These areas 11 are presented with stippling.

(10) In deviation from the example, however, the freedom exists to provide all of the peaks 5 with a uniform degree of gloss or to give the transition areas degrees of gloss that differ from one another if that is desired. This invention basically makes it possible to vary the arrangement of the individual degrees of gloss in any way desired via the application of a digitalized mask and the process steps envisioned for that to create a degree of gloss. If a wood structure is being replicated on the pressed sheet 1 with the etching process that is applied, the possibility exists, as an example, to provide the raised areas 5 with a matte degree of gloss and to provide the lower lying areas that constitute the wood pore with a higher degree of gloss. Because of the possibility of applying several masks and obtaining a certain degree of gloss in a subsequent process step, raised areas that are next to one another can be provided with different degrees of gloss, for instance.

(11) The possibility likewise exists of providing the flanks of individual raised areas with a different degree of gloss to clearly bring out the visual effect of the wood pores. The wood-pore structures that perfectly match the wood decor print are especially highlighted with this measure, and they give the products manufactured with the pressed sheets the appearance of having real wood characteristics that come very close to the natural product.

LIST OF REFERENCE NUMERALS

(12) 1 Pressed sheet 2 Grain 3 Structure 4 Valley 5 Peak 6 Coating 7 Area 8 Area 9 Area 10 Area 11 Area