PRESS ELEMENT AND METHOD FOR MANUFACTURING PRESS ELEMENTS

Abstract

A Press element and a method for manufacturing a structured press element, wherein a heterogeneous mask is applied on a metallic base element, after which a surface treatment is carried out and the heterogeneous mask has a certain resistance to the surface treatment.

Claims

1. A method for manufacturing a structured press element, wherein the method comprises at least the following steps: providing a metallic base element, such as a plate or a roller; applying a mask on a surface of the metallic base element, wherein the mask has a certain resistance to a surface treatment so as to cover the surface at least temporarily from the surface treatment at the level of the mask; carrying out the surface treatment; wherein said mask has a heterogeneous build, and at least the build determines the extent of said resistance to the surface treatment.

2. The method in accordance with claim 1, wherein the mask divides said surface of the metallic base element into one or more shielded portions, on which the mask is located, and one or more non-shielded portions, on which there is no or hardly any mask, and wherein the mask comprises one or more edge portions and one or more internal portions, wherein the one or more internal portions are each completely surrounded by one or more adjoining edge portions, and the one or more edge portions extend between one or more adjoining non-shielded portions of the surface, and one or more adjoining internal portions of the mask, wherein the method comprises one or more of the following features, provided these are not incompatible: the build of the mask is such that at the level of at least one aforementioned edge portion, the resistance to the surface treatment increases, preferably increases gradually, from a respective adjoining non-shielded portion to a respective adjoining internal portion; the build of the mask is such that at the level of at least one aforementioned edge portion, the thickness of the mask increases, preferably increases gradually, from a respective adjoining non-shielded portion to a respective adjoining internal portion; the build of the mask is such that the resistance to the surface treatment at the level of at least one aforementioned internal portion is greater than the resistance to the surface treatment at the level of a respective adjoining edge portion; the chemical composition of an aforementioned edge portion differs from the chemical composition of a respective adjoining internal portion; the mask is made from at least one curable substance, wherein the degree of cure at the level of an aforementioned edge portion is lower than the degree of cure at the level of a respective adjoining internal portion; the aforementioned one or more edge portions all have an identical first chemical composition and the aforementioned one or more internal portions all have an identical second chemical composition, wherein the first chemical composition is less resistant to the surface treatment than the second chemical composition; the mask is at least printed on the surface, use is made of at least two printheads, each being intended to print with an ink with a different composition, in order to print a heterogeneous mask, wherein preferably the edge portions are printed with one said printhead and the internal portions are printed with the other said printhead.

3. The method in accordance with claim 1, wherein the surface treatment comprises one or more of the following treatments: an etching treatment, a sandblasting treatment or a polishing treatment.

4. The method in accordance with claim 1, wherein said surface treatment comprises at least one etching treatment, and wherein the etching treatment preferably comprises two or more sub-steps, in which in each case an etchant is brought into contact with said surface and wherein preferably etching parameters, such as the etchant used, the temperature of the etchant, the flow rate of the etchant, the etching time, etc., are identical in said two or more sub-steps, or at least differ for one etching parameter.

5. The method in accordance with claim 4, wherein in two sub-steps, possibly following each other directly, called a first sub-step and a second sub-step hereinafter, the etching parameters are different at least for one parameter, wherein the edge portions break down at least partially during the first sub-step and the edge portions have completely broken down after the second sub-step, and wherein the internal portions still cover the same portion of the surface of the metallic base element after the second sub-step.

6. The method in accordance with claim 4, wherein the mask breaks down partially during one or more of said sub-steps.

7. The method in accordance with claim 4, wherein at least the edge portions break down almost completely during one or more of said sub-steps.

8. The method in accordance with claim 1, wherein the build of the mask is heterogeneous on account of one or more of the following points of difference from the list comprising: thickness, chemical composition, degree of cure, strength of bond with the surface.

9. The method in accordance with claim 1, wherein the mask is printed on the surface, preferably is digitally printed, and wherein preferably the mask is printed on the surface with different thicknesses.

10. The method in accordance with claim 1, wherein the mask comprises at least one curable substance, wherein the mask, after application thereof on the surface, is cured and wherein the curing is uneven, so that the mask comprises portions with a higher degree of cure and portions with a lower degree of cure.

11. The method in accordance with claim 10, wherein the curing of the mask takes place by means of a curing source, wherein the curing source is controlled digitally, comprises a digitally controlled curing beam, and/or the curing source is controlled in register with the applied mask.

12. A press element for manufacturing coated panels, wherein the press element comprises a metallic base element with a surface structure obtained by a surface treatment, wherein the surface treatment preferably comprises an etching treatment, wherein the surface structure at least comprises one or more base portions that together form a base and one or more structural portions which form bulges relative to the base, wherein the base portions preferably have a sloping transition into the structural portions.

13. The press element in accordance with claim 12, wherein the structural portions comprise one or more foot portions and one or more central portions, wherein the one or more central portions are each completely surrounded by one or more adjoining foot portions, and the one or more foot portions extend between one or more adjoining base portions, and one or more adjoining central portions, wherein the central portions are located at a maximum distance from the base, viewed in a direction perpendicular to the base or perpendicular to a tangent to the base, and wherein the maximum distance of the foot portions from the base gradually increases from the adjoining base portion to the adjoining central portion, preferably at a constant rate of increase.

14. The press element in accordance with claim 12, wherein the maximum distance between the top of an aforementioned central portion and the base portion is at least 0.1 mm, preferably at least 0.3 mm and most preferably at least 0.5 mm and/or wherein the maximum distance between the top of an aforementioned central portion and the base portion is at most 30 microns, preferably at most 15 microns.

15. The press element in accordance with claim 12, wherein the transition between the foot portions and the base portions has the form of a rounded obtuse angle.

16. The press element in accordance with claim 12, wherein the foot portions form part of the flanks of the structural portions or contribute to formation of the flanks of the structural portions, wherein these flanks are free from sharp points and preferably each extend substantially according to a constant slope angle with the base.

17. The press element, optionally in accordance with claim 12, wherein the press element is obtained by a method comprising: providing a metallic base element, such as a plate or a roller; applying a mask on a surface of the metallic base element, wherein the mask has a certain resistance to a surface treatment so as to cover the surface at least temporarily from the surface treatment at the level of the mask; carrying out the surface treatment; wherein said mask has a heterogeneous build, and at least the build determines the extent of said resistance to the surface treatment.

18. A coated panel, wherein the upper surface of the coated panel comprises a surface structure with one or more base portions which each extend in an almost identical base plane and one or more recesses, wherein these one or more recesses preferably have a sloping transition into the one or more base portions.

19. The coated panel in accordance with claim 18, wherein the recesses comprise one or more edge portions and one or more internal portions, wherein the one or more internal portions are each completely surrounded by one or more adjoining edge portions, and the one or more edge portions extend between one or more adjoining base portions, and one or more adjoining internal portions, wherein the internal portions are located at a distance from the base, viewed in a direction perpendicular to the base, and wherein the distance from an aforementioned edge portion to the base gradually increases from the respective adjoining base portion to the respective adjoining internal portion.

20. The coated panel, optionally in accordance with claim 18, wherein the coated panel is obtained by pressing with a press element wherein the press element comprises a metallic base element with a surface structure obtained by a surface treatment, wherein the surface treatment preferably comprises an etching treatment, wherein the surface structure at least comprises one or more base portions that together form a base and one or more structural portions which form bulges relative to the base, wherein the base portions preferably have a sloping transition into the structural portions.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0080] For better illustrating the features of the invention, some preferred embodiments are described hereunder, as examples without any limiting character, referring to the appended drawings, in which:

[0081] FIG. 1 is a schematic representation of a cross section of a press plate according to the second aspect of the invention;

[0082] FIG. 2 is a schematic representation of a cross section of a metallic base element on which a mask is applied for manufacturing the press plate shown in FIG. 1, according to a first embodiment of a method according to the first aspect of the invention;

[0083] FIG. 3 is a schematic representation of a cross section of a metallic base element on which a mask is applied for manufacturing the press plate shown in FIG. 1, according to a second embodiment of a method according to the first aspect of the invention;

[0084] FIG. 4 is a schematic representation of a cross section of a metallic base element on which a mask is applied for manufacturing the press plate shown in FIG. 1, according to a third embodiment of a method according to the first aspect of the invention;

[0085] FIG. 5 is a schematic representation of a cross section of a metallic base element on which a mask is applied for manufacturing the press plate shown in FIG. 1, according to a fourth embodiment of a method according to the first aspect of the invention;

[0086] FIG. 6 is a schematic perspective view of a portion of a coated panel according to the third aspect of the invention, obtained with a press plate as shown in FIG. 1;

[0087] FIG. 7 is a schematic representation of a perspective view of a portion of a press plate according to the invention;

[0088] FIG. 8 is a schematic representation of a top view of a metallic base element on which a mask is applied for manufacturing the press plate shown in FIG. 1, according to the third embodiment of a method according to the first aspect of the invention;

[0089] FIG. 9 shows schematically some steps in a method according to the fourth aspect of the invention;

[0090] FIG. 10 shows a variant in a view on the area indicated with F10 in FIG. 9.

[0091] The reference numbers used in the FIGS. 9 and 10 are defined by means of the paragraphs above.

DETAILED DESCRIPTION OF THE INVENTION

[0092] The present invention according to the fourth aspect is in no way limited to the above-described embodiments, but such methods may be realized according to several variants without leaving the scope of the invention.

[0093] The press plate 1 that is described here is intended to form coated panels 4 with deep structures 7, being notches 7 with a maximum depth of more than 0.15 mm, preferably more than 0.3 mm. The present invention is not, however, limited to this. Thus, the present invention also relates to press plates/coated panels with microstructures as well as to press plates/coated panels with microstructures and with high/deep structures. Here, the press plate 1 comprises a base portion that forms a base and one or more structural portions 8 that form bulges relative to the base, wherein the base portion has a sloping transition into the structural portions 8. The structural portions 8 each comprise a foot portion 8b and a central portion 8a, wherein each central portion 8a is completely surrounded by the adjoining foot portion 8b, and each foot portion 8b extends between the base portion and the adjoining central portion 8a. The difference between the foot portions 8b and the central portions 8a is not visible in the press plate 1 obtained. This is represented by lines in FIG. 1. This is possible because the foot portions 8b extend at the level of the edge portions 3b of the mask 3 that decompose during the surface treatment (see hereunder) and the central portions 8a extend at the level of the internal portions 3a of the mask 3 (see hereunder) in such a way that the position of said foot portions 8b and the central portions 8a coincide with the positions of the edge portions 3b and the internal portions 3a of the mask 3.

[0094] The press plate 1 shown schematically in FIG. 1 has a maximum height h and can be obtained in various ways. Referring to FIGS. 2 to 5, four possible methods are discussed below, all relating to methods according to the invention.

[0095] These methods all have the following features in common:

it always relates to a method for manufacturing a structured press element 1, wherein these methods comprise at least the following steps:
providing a metallic base element 2 with a height h, being a plate comprising a surface to be structured, wherein the plate is for example made of steel with optionally a copper coating at the level of the surface to be structured. The metallic base elements 2 shown here are plate-shaped, but cylindrical metallic base elements are for example also possible for obtaining structured embossing rollers (not shown here).
applying a mask 3 on a surface of the metallic base element 2, wherein the mask 3 has a certain resistance to a surface treatment so as to cover the surface from the surface treatment at the level of the mask 3;
carrying out the surface treatment;
removing the mask 3;
wherein said mask 3 has a heterogeneous build, and at least this build determines the extent of said resistance to the surface treatment.

[0096] In these methods, the surface treatment comprises at least one etching treatment. This etching treatment comprises two or more sub-steps, wherein in each sub-step said surface is brought into contact with an etchant, for example by introducing the metallic base element 2 with the mask 3 applied thereon into an etch bath comprising an etchant, so that the surface and the mask 3 come into contact with the etchant. Thus, for example in each sub-step the metallic base element 2 can be immersed in the etchant, for a number of minutes, for example 1, 2, 3, 4, 5, 6 or more minutes. The etchant may also be sprayed on the metallic base element 2.

[0097] As can be seen in FIGS. 2 to 4, the mask 3 divides said surface of the metallic base element 2 into one or more shielded portions, on which the mask 3 is located, and one or more non-shielded portions, on which there is no mask 3, and the mask 3 comprises several edge portions 3b and several internal portions 3a, wherein the internal portions 3a are each completely surrounded by adjoining edge portions 3b, and the edge portions 3b extend between one or more adjoining non-shielded portions of the surface, and one or more adjoining internal portions 3a of the mask 3.

[0098] It can be seen in FIG. 5 that the entire surface is covered with the mask 3, wherein certain portions are only covered with a thin base layer 3c. In view of the small thickness of this base layer 3c and since this base layer 3c will quickly disappear during the surface treatment, for simplicity the portions of the surface that are only covered by the base layer 3c are also indicated here as non-shielded portions as described above. Therefore, said non-shielded portions and shielded portions are also applicable in this case. The mask 3 further comprises bulges 3d relative to the base layer 3c, wherein these bulges 3d also comprise said edge portions 3b and internal portions 3a (not shown in the figure), wherein the edge portions 3b extend between the adjoining base layer 3c and respective adjoining internal portions 3a. FIGS. 2 to 5 are thus discussed together hereunder.

[0099] The masks 3 shown in FIGS. 2 to 5 all have a heterogeneous build, so that the resistance of the mask 3 is not identical everywhere and the etching treatment at certain places will or will not be able to remove material from the metallic base element 2. At the places where the etching treatment is able to remove material, this may take place during the complete etching treatment and/or only starting from a certain sub-step and/or after a certain time.

[0100] As shown in FIG. 2, the mask 3 is built up from one material, for example a wax or a varnish or one ink, wherein the thickness of the mask 3 is heterogeneous. The build of the mask 3 is such that on said edge portions 3b, the thickness of the mask 3 increases from the respective adjoining non-shielded portions to the adjoining internal portions 3a, wherein this increase is gradual. Owing to this build, the resistance of the edge portions 3b of the mask 3 increases from respective adjoining non-shielded portions to respective adjoining internal portions 3a, and in this case gradually. The result is that during the etching treatment, the edge portions 3b will degrade from the non-shielded portions toward the internal portions 3a, so that a press element 1 with sloping transitions between the base portions and the structural portions 8 is obtained, with structural portions 8 comprising said foot portions 8b and central portions 8a. Since this is only a question of a thickness difference, and the material is always the same, the edge portions 3b and the internal portions 3a are not shown here as separate components of the mask 3, since the edge portions 3b and the internal portions 3a are also not visible in practice as separate components of the mask 3. In practice, only sloping bulges are visible.

[0101] In FIG. 3, the mask 3 always has roughly the same thickness, but the mask 3 is built up from two materials, namely a first material and a second material, wherein the resistance of the first material to the etching treatment is greater than the resistance of the second material to the etching treatment. The edge portions 3b are built up from the second material and the internal portions 3a are built up from the first material. The result is that during the etching treatment, the edge portions 3b will degrade from the non-shielded portions toward the internal portions 3a, so that a press element 1 with sloping transitions between the base portions and the structural portions 8 is obtained, with structural portions 8 comprising said foot portions 8b and central portions 8a. Thus, it is possible that during a sub-step of the etching treatment, use is made of an etchant, wherein the second material is not resistant to this etchant and the first material is resistant or is more resistant than the second material. The result is that during this sub-step at least the second material and thus at least the edge portions 3b degrade. It is then possible to work with an additional sub-step, wherein the surface at the level of the edge portions 3b, which have disappeared, is processed. Optionally the surface treatment may comprise yet other additional treatments such as sandblasting, for example to reduce the thickness of the mask 3 gradually at the level of the edge portions 3b toward the non-shielded portions, prior to the etching treatment. This additionally ensures that the edge portions 3b will gradually decrease, from the non-shielded portions toward the internal portions 3a, so that the transitions between the foot portions 8b and central portions 8a of the press element 1 obtained are very sloping.

[0102] In FIG. 4, the thickness of the mask 3 is heterogeneous. The build of the mask 3 is such that on said edge portions 3b, the thickness of the mask 3 increases from the respective adjoining non-shielded portions to the adjoining internal portions 3a, wherein this increase is gradual. Moreover, the mask 3 is built up from two materials, namely a first material and a second material, wherein the resistance of the first material to the etching treatment is greater than the resistance of the second material. The edge portions 3b are built up from the second material and the internal portions 3a are built up from the first material. The result is that during the etching treatment, the edge portions 3b will gradually degrade from the non-shielded portions toward the internal portions 3a, so that a press element 1 with sloping transitions between the base portions and the structural portions 8 is obtained, with structural portions 8 comprising said foot portions 8b and central portions 8a.

[0103] As shown in FIG. 5, the mask 3 is built up from one material, for example a wax or a varnish or one ink, wherein the thickness of the mask 3 is heterogeneous. The build of the mask 3 is such that on said edge portions 3b, the thickness of the mask 3 increases from the respective adjoining non-shielded portions to the adjoining internal portions 3a, wherein this increase is gradual. Moreover, the mask 3 always comprises a base layer 3c, which covers the whole area of the surface, in such a way that the edge portions 3b always have a transition into the base layer 3c. Owing to this build, the resistance of the edge portions 3b of the mask 3 increases from respective adjoining non-shielded portions to respective adjoining internal portions 3a, and gradually in this case. The result is that during the etching treatment, the base layer 3c degrades almost immediately and the edge portions 3b will degrade from the non-shielded portions toward the internal portions 3a, so that a press element 1 with sloping transitions between the base portions and the structural portions 8 is obtained, with structural portions 8 comprising said foot portions 8b and central portions 8a. Another option is that prior to the etching treatment, another type of surface treatment is carried out, such as sandblasting, polishing, a laser treatment—such as laser ablation—wherein the base layer 3c is removed from the mask 3. Removal of the base layer 3c may for example take place in register.

[0104] By means of the press element 1 as obtained by the aforementioned methods, a laminated panel 4 may be pressed. This laminated panel 4 comprises for example a hard core/substrate 6 made of for example MDF, HDF, particle board, a mineral-based board, a thermoplastic-based board, wherein a top layer 5 comprising one or more sublayers is applied on top of this hard core/substrate 6, wherein these sublayers may comprise resin-impregnated papers, thermoplastic layers, etc. Here, the press plate 1 is able to transfer its relief onto the top layer 5. The result is a top layer 5 comprising a base plane 9 and sloping recesses 7 relative to this base plane 9.