Pressing element and related methods

Abstract

Pressing element (1) for manufacturing decorative panels, which pressing element (1) exhibits a press surface (4), with a press structure (5) for forming a structure on at least one said decorative panel, wherein the pressing element (1) comprises at least two press parts (2), each exhibiting a partial press surface (6) with a partial press structure (7) and being couplable for forming said pressing element (1), the partial press surfaces (6) thereby together forming said press surface (4) and the partial press structures (7) together forming said press structure (5), wherein the press parts (2) are provided on facing edges (14), which in a coupled position face each other, with retaining means (15), for securing said press parts (2) relative to each other. The invention also relates to a method for manufacturing such pressing element (1) and a method for manufacturing decorative panels, using such pressing element (1).

Description

[0001] PRESSING ELEMENT AND RELATED METHODS

[0002] The present invention relates to pressing elements and to a method for manufacturing pressing elements, wherein these pressing elements can be used for manufacturing decorative panels.

[0003] Such pressing elements can be used in a single daylight press or in a multi daylight press. At least one pressing element, for example a press plate, is a structured pressing element. For example with a single daylight press, a lower press plate and an upper press plate can be provided, with the upper press plate or the lower press plate being a structured pressing element or with both the upper press plate and the lower press plate being structured pressing elements.

[0004] More specifically, the invention relates to the manufacture of pressing elements which are employed in a method for manufacturing decorative panels, wherein the decorative panels are of the type that comprises a substrate and a decorative top layer applied thereto.

[0005] These can for example be floor panels or wall panels or furniture panels, which are primarily composed of:

[0006] - Optionally, a balancing layer, preferably a resin impregnated paper;

[0007] - a substrate, for example an MDF or HDF (medium-density or high-density fiberboard) panel or a mineral based substrate, such as an MgO (Magnesium Oxide) panel, or a particle board, or a substrate comprising thermoplastic material, etc;

[0008] - and a decorative top layer applied thereto, such as a laminate top layer, which comprises for example a resin impregnated printed paper.

[0009] The resin can be any type of resin which has some flow when being heated, for example a thermosetting resin such as a melamine resin or an acrylate resin or a polyester resin. In particular, the invention relates to pressing elements which are used in a method for manufacturing decorative panels with a printed decor and a transparent or translucent wear layer extending on top thereof. It is known that such a decor may be printed directly onto the substrate, optionally with the use of primer layers. However, the decor may also be provided on a sheet of material, such as a sheet of paper or a plastic film, which is incorporated in the aforementioned top layer. The transparent or translucent wear layer forms a protective layer on top of the printed decor and may, for example, comprise wear-resistant particles such as aluminium oxide or corundum. It is not ruled out that this protective layer also comprises a sheet of material, such as a sheet of paper or plastic film. By way of example, this may concern the manufacture of laminate floor panels, for example according to a DPL (direct pressure laminate) or HPL (high pressure laminate) technique. In the case of a DPL technique, one or more sheets of material preferably provided with resin, together with the substrate, are inserted into a pressing device where they are connected both to one another and to the substrate by means of a pressing element and under the action of elevated pressure and temperature. In the case of an HPL technique, the top layer is formed separately on the basis of two or more sheets of material preferably provided with resin before the thus obtained top layer is applied to the substrate, for example by adhesively bonding said top layer to the substrate. According to another possibility, this may concern the manufacture of plastics-based floor panels or floor coatings, such as, for example, vinyl panels, vinyl coating and the like.

[0010] Pressing elements according to the invention are of particular interest for embossing in register (EIR), with shallow and / or deep embossments.

[0011] It is known, for example from WO 01 / 96689 or WO 2014 / 115086, that a relief of impressed portions can be formed on the surface or the decorative side of such decorative panels, whereby it is for example possible for the natural structure of the motif depicted in the aforementioned decor to be imitated. By way of example, in the case where the decor depicts a wood motif, a relief which imitates a wood structure can be realized. Such a wood structure may possibly correspond to the underlying decor, whereby it is then possible to obtain such EIR.

[0012] As is known, structured pressing elements are used to realize a relief on the decorative side. For the manufacture of such pressing elements, various techniques are known, using combinations of one or more of milling, lasering, chemical treatment (e.g. etching with mask). Examples thereof are e.g. disclosed in WO 2006 / 066776, EP 2 123 476, EP 2 251 193, EP 1 987 395 and EP 2 834 076.

[0013] In order to produce decorative panels with such pressing element, use is typically made of large pressing elements, such as large press plates, having dimensions in the order of magnitude of 2,5x5 meters and a thickness of approximately 0,5 cm or more. Typically a plurality of decorative panels is then pressed together out of a larger substrate and corresponding layers and then cut to the required decorative panels. Producing such large pressing elements is however not easy and rather expensive. Maintenance, for example cleaning and reworking, of such large pressing elements is also not easy and cumbersome. To ensure that in case of defects and / or when changing desired decors, complete such large pressing elements do not need to be replaced and in order to simplify the production of such pressing elements, in WO 2006 / 136949, a pressing element is described, comprising several intercouplable press parts. These press parts each exhibit a partial press surface with a partial press structure, which in coupled position together form a press surface, extending essentially in a plane and being provided with a press structure for forming a structure on at least one decorative panel.

[0014] A disadvantage of such intercouplable press parts is that at pressing of decorative panels with resin layers, resin can undesirably build up between the press parts. Such resin can come off again when pressing further decorative panels and can contaminate these further decorative panels. Also EIR becomes more difficult or is no longer possible. When the pressing element becomes too contaminated, the press is to be shut down for cleaning to avoid contamination of further decorative panels. An object of the present invention is therefore to provide an improved pressing element and related method limiting accumulation of resin between the press parts.

[0015] In order to avoid this, several solutions can be considered:

[0016] - a filling means can be provided in the gaps in order to prevent, during pressing, that the resin can rise up between the press parts. Herein, use of a of suitable filling agent has been considered, thus, for example: o a rigid filling means, such as an insertion strip corresponding or approximately corresponding to the width of the gap to be filled up, for example, a series of metal laths with different widths, from which then, in function of the mutual distance to be realized between the press parts, the most suitable lath is selected; o a filling means that adapts to the width of the respective gap;

[0017] - the lateral edges and / or edges of the press parts can be treated in order to exclude the adhesion of resin, for example, by inclining the lateral edges and / or to provide them with a coating in order to reduce the risk of adhesion, for example, by chromium- plating the lateral edges.

[0018] One or more of these solutions can be used, and this whether or not in combination with a below mentioned aspect of the invention.

[0019] The invention, according to a first aspect, is a pressing element for manufacturing decorative panels, such as laminate panels, wherein the pressing element exhibits a press surface extending essentially in a plane and being provided with a press structure for forming a structure on at least one said decorative panel, wherein the pressing element comprises at least two press parts, each exhibiting a partial press surface with a partial press structure and being couplable for forming said pressing element, the partial press surfaces thereby together forming said press surface and the partial press structures together forming said press structure and wherein the press parts are provided on facing edges, which in a coupled position face each other, with retaining means, for securing said press parts relative to each other, preferably at least in a securing direction extending perpendicular to said plane.

[0020] The retaining means avoid shifting of the press parts, and this preferably at least in the securing direction relative to each other. Sagging increases the suction of resin that accumulates between the press parts until it becomes problematic and requires cleaning. The retaining means keep the press parts together in such a way that possible sagging can be limited or prevented.

[0021] The press parts are preferably plate-shaped.

[0022] The retaining means preferably extend over substantially the entire length of the corresponding facing edges.

[0023] The facing edges preferably comprise facing side surfaces, which in a coupled position face each other, wherein the retaining means are preferably provided on said facing side surfaces of the press parts.

[0024] More specifically, the retaining means can be provided such that, in a coupled position, a slotted chamber extends between the facing side surfaces. In said slotted chamber, said resin can be collected. Such a slotted chamber may be provided primarily in either facing side surface or may be substantially formed by both facing side surfaces.

[0025] Such slotted chamber preferably extends in the length direction of such facing side surface and this preferably substantially along the entire length of such facing side surface.

[0026] In a specific embodiment, the retaining means comprise a corresponding tongue and groove on said facing side surfaces, which tongue and groove are interengaging for securing said press parts. Preferably said tongue and groove are substantially realized from the material of the press parts itself. When the tongue and groove are realized from the material of the press parts itself, the risk that the press parts will become separated from each other during use of the pressing element, is low. Said tongue or said groove can be provided with a separate insert which, in coupled condition of said press parts, contacts both press parts. Said tongue can be a separate insert, wherein for example said press parts both comprise a groove and said separate insert is provided to extend in both grooves in coupled condition of said press parts. A said insert is preferably made from a heat resistant material, such that it does not degrade when using the pressing element.

[0027] Further preferably the retaining means can comprise at least one seal which is provided to extend between the tongue and the groove. This seal is then for example a strip or a tape, preferably a flexible strip or tape, which is provided between at least a part of the tongue and groove, as such ensuring a form fit and / or secured coupling between the press parts. For example a strip / tape made from a heat resistant material can be provided, for example glued, upon part of the outer surface of the tongue or groove. Said strip / tape can be made from a soft metal such as lead or copper.

[0028] More specifically, a first said press part can then comprise a substantially wedgeshape tongue as said tongue and a second said press part a corresponding substantially wedge-shaped groove as said groove, wherein the wedge-shaped tongue is provided to engage in the wedge-shaped groove for securing said press parts.

[0029] The wedge-shaped tongue is then preferably positioned further from said partial press surface than from a partial mounting surface of the first press part opposite to said partial press surface. However, it is also possible to position such wedge-shaped tongue at equal distances from both the partial press surface and the partial mounting surface, or to position such wedge-shaped tongue closer to said partial press surface than to the partial mounting surface. Said partial mounting surfaces together form a mounting surface, wherein said mounting surface is opposite said press surface and wherein preferably said mounting surface and said press surface extend parallel to each other. The wedge-shaped tongue can more specifically be truncated. Such a tongue can be well formed and such a tongue and wedge connection is less prone to milling tolerances, such that a good connection between the tongue and groove is always ensured.

[0030] In order to provide a said slotted chamber with embodiments with tongue and groove, the slotted chamber can be formed by the tongue engaging in the groove.

[0031] More specifically, with a said truncated wedge-shaped tongue, the slotted chamber can be formed by the truncated tongue engaging in the wedge-shaped groove. The corresponding wedge-shape groove can be non-truncated.

[0032] Additionally or alternatively, it is possible to provide the corresponding groove with a chamber, which opens in this groove for forming said slotted chamber.

[0033] The invention, according to the second aspect of the invention, relates to a pressing element according to the first aspect of the invention, wherein in addition to the said retaining means or as an alternative to said retaining means, each press part, or at least one press part, is preferably provided on the corresponding facing edge with a nose, extending upright with respect to the partial press surface, to make flow of the resin towards the transition between two said facing edges, for example towards a said facing side surface, more difficult. When such nose or noses are present, the feature ‘the press parts are provided on facing edges with retaining means’, can be optional. Of course, better results are obtained when both the nose / noses and the retaining means are present.

[0034] Such a nose preferably has an approach surface for said resin that extends substantially transvers to the partial press surface. Preferably, said approach surface is the surface of the nose located closed to the partial press structure and the furthest of a said facing side surface.

[0035] Where retaining means are provided on facing side surfaces of the press parts, such a nose is preferably set up at an intermediate distance from the facing side surface of this press part. This distance is preferably measured according to a direction perpendicular to the face surface and in the plane of the press surface.

[0036] In preferred embodiments of the first aspect and / or the second aspect of the invention, the press structure comprises at least two panel structures, each for forming a said structure on one said decorative panel and a technical zone, extending between the panel structures. Each partial press structure then preferably comprises at least one said panel structure. Said retaining means and / or said noses are then preferably provided in the technical zone.

[0037] All press parts of a pressing element according to the first aspect and / or the second aspect of the invention, in a coupled state, preferably only border each other at facing edges that extend in one direction, such that it is easier to align these press parts when coupling them for forming said pressing element.

[0038] It is however also possible to provide press parts wherein first press parts in a coupled state border each other at facing edges extending in a first direction and second press parts in a coupled state border each other at facing edges extending in a second direction, transversely to the first direction. It could be more difficult to align these press parts when coupling them.

[0039] To invention, according to a third aspect, relates to a pressing element according to the first and / or second aspect of the invention, wherein in addition to respectively the said retaining means and / or in addition to said nose / noses, or as an alternative to respectively said retaining means and / or said nose / noses, the press parts are preferably provided at mounting edges - which mounting edges extend transversely to said facing edges of the press parts- with gripping devices for holding the press parts. The feature ‘the press parts are provided on facing edges with retaining means and / or the feature ‘the press parts comprise noses’ are thus optional.

[0040] Such gripping devices are provided to engage upon said mounting edges, for coupling the press parts. Such press parts are then held together and can be coupled to each other by means of such gripping devices, and this preferably in a direction transversely to abovementioned securing direction.

[0041] Such gripping devices can be connected to the press parts by means of bolts and / or by means of welding, etc.

[0042] In embodiments wherein the press structure comprises at least two panel structures, each for forming a said structure on one said decorative panel and a technical zone, extending between the panel structures, the press parts preferably also comprise edge zones extending along said panel structures at said mounting edges. The gripping devices are then preferably mounted to the mounting edges in said edge zones and this more preferably to the mounting surface.

[0043] In a specific embodiment, a first said gripping device, provided at a first said press part and a second said gripping device, provided at a second said press part are provided to border each other in the coupled position of the press parts and are intercouplable.

[0044] In a simple embodiment the gripping devices can extend up to the corresponding facing side surface of the corresponding press part.

[0045] To simplify positioning of the press parts and gripping devices relative to each other for coupling, in an alternative embodiment, the first gripping device can extend at a locking distance beyond the facing edge of the first press part, for example be at a locking distance beyond the facing side surface of the first press part, and the second said gripping device can be set up at said locking distance from the facing edge of the second press part, for example be at a locking distance from the facing side surface of the second press part.

[0046] A said gripping device can furthermore be provided at the press parts for intercoupling these press parts. The invention, according to a fourth aspect, is a pressing element according to the first and / or second and / or third aspect of the invention, wherein in addition to respectively the said retaining means and / or said nose / noses and / or said gripping devices, or as an alternative to respectively said retaining means and / or said nose / noses and / or said gripping devices, the pressing element is provided with a pulling screw for intercoupling the press parts, such that a distance between the press parts is settable with this pulling screw. With such pulling screw, the press parts can firmly be coupled. These press parts can also be set apart again with such pulling screw, with a settable distance there between, depending on the conditions for producing the decorative panels.

[0047] Such pulling screw can more specifically be provided for intercoupling the first gripping device and the second gripping device for intercoupling the press parts. In addition to such a pulling screw, a holding pin can be provided to strengthen the intercoupling of the press parts. For example each press part can be provided with a hole, for example a drill hole, wherein said holding pin is provided to be located in both holes of the press parts when the press parts are intercoupled. Said holding pin is preferably located at a distance from the pulling screw.

[0048] In a further specific embodiment of a pressing element according to all aspects of the the invention, the press parts are (at least partially) welded together at the facing edges, the retaining means thereby being formed (at least partially) by welding material.

[0049] A press part of a pressing element according to all aspects of the invention can more specifically comprise at least two partial press parts, each exhibiting part of the partial press surface with part of the partial press structure, wherein at least two partial press parts are welded together to form the said press part. Such press part can more specifically be provided with any of the above described retaining means for securing said press part relative to another press part of the pressing element, such as e.g. a tongue or a groove or welding material, etc. Where the press structure comprises at least two panel structures, each for forming a said structure on one said decorative panel and a technical zone, extending between the panel structures, such partial press parts are then preferably welded together in such a technical zone. The smaller such partial press parts, the easier it is to produce these partial press parts.

[0050] In case of a defect at one such partial press part, such weld can e.g. be cut out and the partial press part can be maintained separately or replaced and welded again adding extra welding material.

[0051] The invention, according to a fifth aspect, is an assembly of pressing element according to any of the abovementioned aspects and a protection for protecting a said facing edge. The facing edge can be protected from deposition and / or protected from impacts. Protection against deposition is important when said press parts are maintained, for example cleaned and / or reworked. Protection from impacts is important for transportation and / or storage of said press parts.

[0052] A said protection can more specifically be designed as a plastic element which is detachably mountable to said facing edge. Alternatively, a protective coating can be provided to the facing edge for forming such protection. Such a protective coating can be an acid resistant coating and / or an UV resistant coating. Said plastic element can be a plastic cap or a plastic tape. Other protective tapes can also be used. Said protection can be magnetic, for example a magnetic tape, such that it can be easily applied upon / attached to the facing edge.

[0053] Additionally, the invention, according to a sixth aspect, is a pressing machine, comprising an above described pressing element according to any aspect of a pressing element according to the invention.

[0054] Such pressing machine can more specifically be provided with grippers for gripping on above described gripping devices for coupling the press parts, which grippers are preferably movable away from each other and towards each other, for setting a distance between the press parts.

[0055] The pressing machine preferably comprises a base element against which the press parts are mounted in a mounted position. The mounting surface then preferably extends along, for example against, the base element. The mounting surface of the press parts being the surface which extends opposite to the press surface.

[0056] Tension forces occurring when suspending the pressing element in the pressing machine can then substantially be taken up by the base element.

[0057] The invention, according to a seventh aspect, relates to a method for manufacturing a pressing element for manufacturing decorative panels, such as laminate panels, comprising:

[0058] - a step a of providing at least two metal plates;

[0059] - a step b of providing said metal plates with a partial press surface, extending substantially in a plane, said partial press surface comprising a partial press structure;

[0060] - a step c of providing the metal plates couplable at facing edges, for forming press parts which are couplable for forming said pressing element, the partial press surfaces thereby together forming a press surface and the partial press structures together forming a press structure, for forming a structure on at least one said decorative panel; and

[0061] - wherein in step c the metal plates are provided with retaining means at the facing edges, for securing said press parts relative to each other at least in a securing direction extending perpendicular to said plane.

[0062] Said pressing element can be a pressing element according to the first and / or the second and / or the third and / or the fourth aspect of the invention. All the embodiments / features of these last mentioned aspects apply mutatis mutandis for this seventh aspect and vice versa. The metal plates can more specifically be made of steel alloy or copper alloy.

[0063] In step c, the metal plates can in a specific embodiment be welded together at the facing edges, adding a weld as retaining means. The method can further comprise a step d of removing the weld and a step e of rewelding the metal plates together at the facing edges, adding a new weld as retaining means. When the weld is removed in step d, said partial press surface with partial press structure can be cleaned and / or reworked.

[0064] In a preferred embodiment, in step a for at least one metal plate, at least two partial metal plates are provided, which are welded together for forming said metal plate and that in step b the partial metal plates are each provided with part of the partial press surface, comprising part of the partial press structure, wherein the parts of the partial press surface together form the partial press surface. Step b can be performed after the welding together of the at least two partial metal plates, but is preferably performed before the welding together of the at least two partial metal plates. Smaller metal plates can be more easily and more accurately provided with the desired structure. Further preferably the weld between the partial metal plates can be removed again when the press element undergoes maintenance -for example cleaning and / or reworking- such that the partial metal plates can undergo maintenance. It is known that maintenance can be done more easily and accurately on smaller elements.

[0065] Where the press structure comprises at least two panel structures, each for forming a said structure on one said decorative panel and a technical zone, extending between the panel structures, it is then preferably assured that the partial metal plates are welded together in such a technical zone. The smaller such partial metal plates, the easier it is to provide them with a partial press structure in step b.

[0066] Such partial metal plates can then e.g. be welded together using a laser welding machine or any other suitable welding technique. In case of a defect at one such partial metal plates, such weld can e.g. be cut out and the partial metal plate can be maintained separately or replaced and welded again adding extra welding material.

[0067] A press part of a pressing element according to the invention can more specifically comprise at least two partial press parts, each exhibiting part of the partial press surface with part of the partial press structure, which at least two partial press parts preferably being welded together to form the said press part. Such press part can more specifically be provided with any of the above described retaining means for securing said press part relative to another press part of the pressing element, such as e.g. a tongue or a groove or welding material, etc.

[0068] In a very preferred embodiment, in step c, the retaining means are milled in facing side surfaces of facing edges, which in a coupled position face each other. Preferably the retaining means are retaining means as described in the first aspect of the invention.

[0069] In said preferred embodiment, a first said metal plate can be provided with a tongue, which can e.g. be wedge-shaped and a second said metal plate can be provided with a corresponding groove, which can e.g. be wedge-shaped, wherein the tongue is provided to engage in the groove for securing said press parts.

[0070] The tongue and the groove are then preferably milled at a fixed distance from a partial mounting surface of the plates, opposite to said partial press surface. This increases interchangeability of the so obtained press parts and ensures with greater certainty to press flat with a so obtained pressing element.

[0071] Milling at a fixed distance means keeping the milling tool at this fixed distance from the partial mounting surface when milling the tongue and the groove.

[0072] In an embodiment wherein in step c, the retaining means are milled in facing side surfaces of the press parts, the method can more specifically comprise a step f of providing the facing edge of a said metal plate with a protection, after step c. Such protection can be provided for transport purposes, in order not to damage said retaining means. Said protection can also be provided in order to perform step b after step c, in order to protect the facing edge from deposition. Such protection can thus protect the retaining means when providing or maintaining partial press surfaces or parts of such partial press surfaces.

[0073] Partial press surfaces or parts of such partial press surfaces can e.g. be provided and / or maintained with a chrome treatment and / or (vacuum) deposition of a coating and / or etching and / or sanding and / or polishing, etc.

[0074] In order to provide the facing edge with a protection, this protection can e.g. be provided as an abovementioned plastic element and / or tape which is detachably mountable to said facing edge. Alternatively, this facing edge can e.g. be provided with a protective coating as said protection, for example a protective ink such as an acid resistant and / or UV resistant ink or for example an acid resistant wax.

[0075] In a method wherein in a step f the facing edge is provided with a protection, the method can furthermore comprise a step g of providing the press surface of said metal plate with a coating and a step h of removing said protection from said facing edge.

[0076] When the protection is provided as an abovementioned plastic element, which is detachably mountable, this plastic element can easily be detached. When the protection is provided as a protective coating, this protective coating is removed in step h after step g.

[0077] It is particularly suitable to use an above described method according to the invention for manufacturing an above described pressing element according to the invention.

[0078] The invention, according to an eight aspect, is achieved by providing a method for manufacturing decorative panels, such as laminate panels, wherein these decorative panels are provided with a structure by means of a pressing operation, wherein an above described pressing element according to the first and / or second and / or third and / or fourth aspect invention or obtained in accordance with the method according to seventh aspect, is used in the pressing operation. Embodiments and / or features relating to the aspects 1 to 7 also apply mutatis mutandis for the eight aspect and vice versa.

[0079] Furthermore, the invention also relates to a decorative panel, such as a laminate panel, obtained by means of the method according to the eight aspect.

[0080] The present invention will now be explained in more detail by means of the following detailed description of a pressing element and methods according to the present invention. The sole aim of this description is to give explanatory examples and to indicate further advantages and particulars of the present invention, and can thus by no means be interpreted as a limitation of the area of application of the invention or of the patent rights defined in the claims.

[0081] In this detailed description, reference numerals are used to refer to the attached schematic drawings, in which in:

[0082] - Fig. 1 an embodiment of a pressing element according to the invention is illustrated in top view;

[0083] - Fig. 2 an embodiment of a pressing element according to the invention with an already pressed board for forming decorative panels is illustrated in perspective view;

[0084] - Fig. 3 a part of an embodiment of a pressing element according to the invention is illustrated in cross section according to line III-III of figure 1;

[0085] - Fig. 4 a part of an alternative embodiment of a pressing element according to the invention is illustrated in cross section according to line III-III of figure 1;

[0086] - Fig. 5 a part of another alternative embodiment of a pressing element according to the invention is illustrated in cross section according to line III- III of figure 1 ;

[0087] - Fig. 6 a part of an embodiment of a pressing element according to the invention is illustrated in perspective view, of the part shown in F6 of figure 1; - Fig. 7 a further embodiment of a pressing element according to the invention is illustrated in perspective, with a view of the mounting surface thereof;

[0088] - Fig. 8 the pressing element of figure 7 is illustrated in perspective, with a view of the press surface thereof;

[0089] - Fig. 9 an alternative embodiment of the part of fig. 6 is illustrated in perspective view;

[0090] - Fig. 10 a part of an embodiment of a pressing element according to the invention is illustrated in cross section according to line III-III of figure 1, with the press parts placed apart and provided with a protection at the facing edge;

[0091] - Fig. 11 part Fl l of the pressing element of figure 8 is illustrated in more detail;

[0092] - Fig. 12 a part of another alternative embodiment of a pressing element according to the invention is illustrated in cross section according to line III- III of figure 1 ;

[0093] - Fig. 13 a part of another alternative embodiment of a pressing element according to the invention is illustrated in cross section according to line III- III of figure 1 ;

[0094] - Fig. 14 an alternative embodiment of the part of fig. 6 is illustrated in perspective view.

[0095] The illustrated pressing elements (1) are designed to be used for manufacturing decorative panels. These decorative panels are of the type that comprise a substrate and a decorative top layer applied thereto. These can for example be a floor panel or wall panel or furniture panel, which is primarily composed of:

[0096] - Optionally a balancing layer, for example a resin impregnated paper;

[0097] - a substrate, for example an MDF or HDF (medium-density or high-density fiberboard) panel or a mineral based substrate, such as an MgO (Magnesium Oxide) panel, or a particle board, or a substrate comprising thermoplastic material, etc; - and a decorative top layer applied thereto, such as a laminate top layer, which comprises for example a resin impregnated printed paper.

[0098] The resin can be any type of resin which has some flow when being heated, such as a melamine resin or an acrylate resin or a polyester resin.

[0099] In particular, this can be a method for manufacturing decorative panels with a printed decor and a transparent or translucent wear layer extending on top thereof. The decor may be printed directly onto the substrate, optionally with the use of primer layers. However, the decor may also be provided on a sheet of material, such as a sheet of paper or a plastic film, which is incorporated in the aforementioned top layer. The transparent or translucent wear layer forms a protective layer on top of the printed decor and may, for example, comprise wear-resistant particles such as aluminium oxide or corundum. It is not ruled out that this protective layer also comprises a sheet of material, such as a sheet of paper or plastic film. By way of example, this may concern the manufacture of laminate floor panels, for example according to a DPL (direct pressure laminate) or HPL (high pressure laminate) technique. According to another possibility, this may concern the manufacture of plastic-based floor panels, such as, for example, vinyl panels and the like.

[0100] Pressing elements (1) according to the invention are of particular interest for embossing in register (EIR), with shallow and / or deep embossments.

[0101] In order to form the decorative panels, different layers are pressed together in a single daylight press or a multi daylight press, using a pressing element (1) according to the invention at least at one side of the press. For example with a single daylight press, a lower press plate and an upper press plate can be provided, with the upper press plate and / or the lower press plate being a structured pressing element (I).

[0102] By pressing such different layers together, a pressed board (25) as illustrated in figure 2 is obtained. The decorative panels are then obtained by sawing this pressed board (25) to size and possibly providing coupling means at the resultant edges of the panels, for example as described in WO 97 / 47834 and WO 01 / 98603. The pressing elements (1) each exhibit a press surface (4) extending essentially in a plane and being provided with a press structure (5) for forming a structure on at least one said decorative panel.

[0103] In the illustrated embodiments, the pressing elements (1) comprise 4 press parts (2), each exhibiting a partial press surface (6), with a partial press structure (7), the partial press surfaces (6) together forming the press surface (4) and the partial press structures (7) together forming the press structure (5). In alternative embodiments, the pressing elements (1) can comprise more or less such press parts (2). Each of the partial press structures (7) comprises several panel structures (8), each for forming a said structure (26) on one said decorative panel and technical zones (9) extending between the panel structures (8). In the embodiment of figures 1, 7 and 8 each partial press structure (7) is provided with 10 panel structures (8). In the embodiment of figure 2, each partial press structure (7) is provided with 7 panel structures (8). In alternative embodiments, more or less such panel structures (8) can be provided. After pressing, the pressed board (25) is then sawn at the height of the technical zones (9) in order to form the corresponding decorative panels. Said coupling means at the edges of the decorative panels are also provided at the height of these technical zones (9).

[0104] The press parts (2) are attached to each other in a detachable way. In the illustrated embodiments, each press part (2) extends in the width direction (B) of the pressing element (1) over the whole width thereof and comprises a single row of said panel structures (8). In alternative embodiments, press parts (2) could extend over part of this width, or could extend in the length direction (L) of such pressing element (1) over the whole or part of the length thereof. In still alternative embodiments, press parts (2) could comprise several rows of said panels structures (8). Preferably, for ease of mounting, all press parts (2) either extend in the width direction (B) over the full width, or in the length direction (L) over the full length. For forming the press structure (5), several techniques can be used, such as combinations of one or more of milling, lasering, chemical treatment (e.g. etching with mask), etc. Metal plates can in this respect be provided and can further be provided with a partial press surface (6), extending substantially in a plane, said partial press surface (6) comprising a partial press structure (7), using said techniques. The metal plates can more specifically be made of steel alloy or copper alloy.

[0105] In specific embodiments, each press part (2) is made up of (non-illustrated) several partial press parts, which comprise one or more panel structures (8). These partial press parts are preferably welded together, this preferably at the technical zone (9). This can e.g. be done using a laser welding machine. For maintenance, or for replacing a panel structure (8), the welds between such partial press parts can then be cut, to disassemble a said partial press part. Such partial press parts can be maintained with a chrome treatment and / or (vacuum) deposition of coating and / or etching and / or sanding and / or polishing, etc. After maintenance or after replacing the partial press part, this partial press part can then be welded again in the press part (2). Such partial press part can more easily be manufactured and maintained than large pressing elements (1) and even more easily than full press parts (2). More techniques and smaller and thus cheaper machines are available to obtain the desired structures.

[0106] Sagging increases the suction of resin that accumulates between the press parts (2). In order to reduce accumulation of resin between the press parts (2), in the different illustrated embodiments, the press parts (2) are therefore provided on facing edges (14), which in a coupled position face each other, with retaining means (15) for securing said press parts (2) relative to each other, preferably at least in the height direction (H). This height direction (H) extends perpendicular to the plane in which the press surface (4) essentially extends. In the illustrated embodiments, the retaining means (15) are provided on facing side surfaces (13) of the facing edges (14) of the press parts (2), which in a coupled position face each other, and extend over the entire length of these surfaces (13).

[0107] These retaining means (15) are provided in the technical zone (9).

[0108] In the embodiments as illustrated in the figures 3-6 and 9-10 and 12-13, the press parts (2) are provided on said facing side surfaces (13) with a corresponding tongue

[0109] (17) and groove (18), which are interengaging for securing the press parts (2).

[0110] In figures 3-6 and 9-10 and 13, the press part (2) each time illustrated at the left is in this respect provided with a wedge-shaped groove (18), whereas the press part (2) each time illustrated at the right is provided with a wedge-shaped tongue (17). In figure 12 the press part (2) illustrated at the left is in this respect provided with a groove, whereas the press part (2) illustrated at the right is provided with a groove and the retaining means (15) additionally comprise an insert (29) which is provided to extend in both said grooves in coupled condition of said press parts (2).

[0111] In figures 3-4, 6 and 9-10 and 13, the tongue (17) and groove (18) are provided at the centre of the corresponding facing side surface (13), each time extending over the full length thereof. In figure 5, the tongue (17) and groove (18) are positioned further from the partial press surface (6) than from the partial mounting surface (11), opposite to said partial press surface (6). Alternatively, the tongue (17) and groove

[0112] (18) can be positioned closer to the partial press surface (6) than to the partial mounting surface (11).

[0113] In the illustrated embodiments, the wedge-shaped tongue (17) is truncated, such that a slotted chamber (16) for collecting resin, is formed by the tongue (17) engaging in the groove (18). The corresponding wedge-shaped groove (18) is non-truncated. Alternatively or additionally, it could be possible to provide this groove (18) with a chamber, which opens in the groove (18) in order to form said slotted chamber (16).

[0114] In alternative embodiments, the tongue (17) and groove (18) can assume different forms. Such different forms can similarly be provided such that a slotted chamber (16) is formed by the tongue (17) engaging in the groove (18). Still in alternative embodiments, several tongues (17) and several grooves (18) can be provided at the respective facing side surfaces (13). In doing so, it is also possible to provide each facing side surface (13) with at least one tongue (17) and at least one groove (18).

[0115] In order to provide the press parts (2) with one or more said tongue (17) and groove (18), such tongue (17) and groove (18) can e.g. be milled in the facing side surfaces (13) of the metal plates out of which the press parts (2) are formed. When milling such tongue (17) and corresponding groove (18), these tongue (17) and groove (18) are preferably milled with a milling tool which distance (Zi) with respect to the partial mounting surface (11) is kept at a fixed distance. Alternatively, such tongue

[0116] (17) and groove (18) can be milled with a fixed distance (Z2) of the milling tool with respect to the partial press surface (6).

[0117] As can be seen in figure 12, the retaining means (15) comprise an additional strip (28) which is provided to extend between the groove (18) and tongue (17). This strip (28) is preferably a heat resistant plastic material, such as polytetrafluoroethylene, or can be a soft metal such as copper or steal. As can be seen in figure 12, this strip (28) does not cover the entire tongue (17) and groove (18) coupling, and therefore does not cover the entire surface of the facing side surfaces (13). However, embodiments where the strip covers the entire height of the facing side surface (13) or the entire wedge-shaped tongue (17) or groove (18), are possible. Also the strip can have smaller dimensions then indicated in figure 12.

[0118] After providing such tongue (17) and groove (18), the facing edges (14) can be provided with a protection (22) to avoid damaging these edges (14) for transport, or for providing the press parts (2) with said partial press structure (7) or for maintaining such partial press structure (7). This protection (22) can be provided as a plastic element / cap as illustrated in figure 10, or can e.g. be provided as a protective coating as said protection or as a (magnetic) tape. After providing the press parts (2) with said partial press structure (7) and / or after maintenance and / or after transport, such protection (22) is to be removed. In alternative embodiments, a said slotted chamber (16) for collecting resin, can be formed in the facing side surfaces (13), without these facing side surfaces (13) being provided with corresponding tongue (17) and groove (18). The press parts (2) can then be secured in other ways. Such slotted chamber (16) may be provided primarily in either facing side surface (13) or may be substantially formed by both facing side surfaces (13).

[0119] In the embodiments, as illustrated in figures 3-5, 10, 12 and 13, the press parts (2) are provided on corresponding facing edges (14) with a nose (19), extending upright with respect to the partial press surface (6), in order to make flow of the resin towards the facing side surface (13) more difficult. This nose (19) is provided in the technical zone (9), as illustrated in figure 11. Such a nose (19) can e.g. be formed together with the partial press structure (7). Each nose (19) is provided with an approach surface (24) for said resin, which extends obliquely to the partial press surface (6). The technical zone (9) can mainly be situated lower than the partial press structure (7), in order to address press defects. Such a nose (19) can thus be provided in this technical zone (9) in such a way that it does not extend above the partial press structure (7) and thereby does not hinder pressing of the boards to be pressed.

[0120] In figure 3, each nose (19) is provided at the facing edge (14) of the corresponding partial press surface (6), such that the noses (19) face each other in coupled position. In the embodiments in figures 4-5 and 10, each nose (19) is positioned at an intermediate distance (X) from the facing side surface (13) of the corresponding press part (2).

[0121] The press parts (2) can be mounted directly to a pressing machine or the pressing machine can be provided with a base element against which the press parts (2) are mounted in the mounted position with their mounting surface (3). Tension forces occurring when suspending the pressing element (1) in the pressing machine can substantially be taken up by such base element. It is then also possible to couple the press parts (2) by coupling them to such base element. Press parts (2) can be provided to be mounted in a specific position and in a specific orientation in a pressing element (1). Alternatively it is possible to provide the press parts (2) such that several press parts (2) in a pressing element (1) are interchangeable. Still alternatively or additionally, it is possible to provide press parts (2) which can be mounted in two opposite orientations in a pressing element (1).

[0122] In order to couple the press parts (2) in a detachable way, they can be provided couplable to each other in a direction transversely to said securing direction (H), in several ways.

[0123] In the embodiments as illustrated in figures 1 and 7-8, the press parts (2) are provided at mounting edges (12) extending transversely to the facing edges (14) with gripping devices (20) for coupling the press parts (2). These gripping devices (20) are preferably coupled to the press parts (2) in an edge zone (10) extending along the panel structures (8) and along the mounting edges (12). Such gripping devices (20) can e.g. be connected to the press parts (2) by means of bolts (23) as illustrated in figures 6 and 9, or by means of welding, etc.

[0124] The pressing machine can then be provided with grippers (27) for gripping on these gripping devices (20) for coupling them to the pressing machine and thereby couple the press parts (2) to each other. In a preferred embodiment, these grippers (27) are then movable away from each other and towards each other, for setting a distance between the press parts (2).

[0125] Alternatively or additionally, gripping devices (20) can be provided for coupling the press parts (2), even without such grippers (27) gripping thereon. In this respect gripping devices (20) can be provided, which are connected to two adjacent press parts (2) in order to couple those press parts (2). Alternatively, as illustrated in the figures 1 and 6-9, gripping devices (20) can be provided at adjacent press parts (2) to border each other, in order to couple them, thereby coupling the press parts (2). Such gripping devices (20) can e.g. interconnected by means of a pulling screw (21), as illustrated in figures 6 and 9. With such pulling screw (21) the distance between the press parts (2) is settable. The press parts (2) can then either be firmly coupled, are set apart with a settable distance, depending on the conditions for producing the decorative panels.

[0126] As illustrated in figure 6, for intercoupling the gripping devices (20), these gripping devices (20) can extend up to the corresponding facing side surface (13) of the corresponding press part (2). To simplify positioning of the press parts (2) and gripping devices (20), a first gripping device (20) can alternatively extend at a locking distance (Y) beyond the facing side surface (13) of a first press part (2), whereas a second gripping device (20) is set at this locking distance (Y) from the facing side surface (13) of the second press part (2), as illustrated in figure 9.

[0127] As illustrated in figure 14, in addition to said pulling screw (21), said gripping devices (20) have drill holes facing each other, wherein a holding pin (30) extends in both said drill holes. Said holding pin (30) provides additional strength. Said holding pin (30) and drill holes are shown in dotted lines, as these are located mainly inside said gripping devices (20) and thus are not visible in said view. Figure 14 also shows the non-visible part of the pulling screw (21) in dotted line.

[0128] In alternative embodiments, it is also possible to provide the retaining means (15) as coupling means for coupling the press parts (2).

[0129] It is e.g. possible to weld the metal plates, from which the press parts (2) are made, together at their facing edges (14), adding a weld as retaining means. For maintenance of the press parts (2) or for replacing a press part (2), it is then possible to cut this weld and after maintenance or replacement to add a new weld as retaining means.

[0130] Alternatively, it is e.g. possible to provide a tongue (17) and groove (18) with an adapted form for intercoupling the press parts (2).

Claims

CLAIMS1. Pressing element (1) for manufacturing decorative panels, such as laminate panels, wherein the pressing element (1) exhibits a press surface (4) extending essentially in a plane and being provided with a press structure (5) for forming a structure (26) on at least one said decorative panel, wherein the pressing element (1) comprises at least two press parts (2), each exhibiting a partial press surface (6) with a partial press structure (7) and being couplable for forming said pressing element (1), the partial press surfaces (6) thereby together forming said press surface (4) and the partial press structures (7) together forming said press structure (5), characterised in that the press parts (2) are provided on facing edges (14), which in a coupled position face each other, with retaining means (15), for securing said press parts (2) relative to each other.

2. Pressing element (1) according to claim 1, characterised in that the facing edges (14) comprise facing side surfaces (13), which in a coupled position face each other, wherein the retaining means (15) are provided on said facing side surfaces (13).

3. Pressing element (1) according to claim 2, characterised in that the retaining means (15) are provided such that, in a coupled position, a slotted chamber (16) extends between the facing side surfaces (13).

4. Pressing element (1) according to claim 2 or 3, characterised in that the retaining means (15) comprise a corresponding tongue (17) and groove (18) on said facing side surfaces (13), which tongue (17) and groove (18) are interengaging for securing said press parts (2).

5. Pressing element (1) according to claim 4, characterised in that a first said press part (2) comprises a substantially wedge-shaped tongue (17) as said tongue and a second said press part (2) comprises a corresponding substantially wedge-shaped groove (18) as said groove, wherein the wedge- shaped tongue (17) is provided to engage in the wedge-shaped groove (18) for securing said press parts (2).

6. Pressing element (1) according to claim 5, characterised in that the wedge- shaped tongue (17) is positioned further from said partial press surface (6) than from a partial mounting surface (11) of the first press part (2) opposite to said partial press surface (6).

7. Pressing element (1) according to one of claims 5-6, characterised in that the wedge-shaped tongue (17) is truncated.

8. Pressing element (1) according to claim 3 and any of claims 4 to 7, characterised in that the slotted chamber (16) is formed by the tongue (17) engaging in the groove (18), preferably by the truncated wedge-shaped tongue (17) engaging in the wedge-shaped groove (18).

9. Pressing element (1) according to any of the claims 4 to 8, wherein the retaining means (15) comprise at least one seal (28) which is provided to extend between the tongue (17) and the groove (18).

10. Pressing element (1) according to any of the preceding claims, characterised in that each press part (2) is provided on the corresponding facing edge (14) with a nose (19), extending upright with respect to the partial press surface (6).

11. Pressing element (1) according to claims 2 and 10, characterised in that the nose (19) of each press part (2) is set up at an intermediate distance (X) from the facing side surface (13) of this press part (2).

12. Pressing element (1) according to any of the preceding claims, characterised in that the press structure (5) comprises at least two panel structures (8), each for forming a said structure (26) on one said decorative panel and a technical zone (9), extending between the panel structures (8), in that each partial press structure (7) comprises at least one said panel structure (8) and in that the retaining means (15) are provided in the technical zone (9).

13. Pressing element (1) according to claim 10 or 11 and claim 12, characterized in that the nose (19) of each press part (2) is provided in the technical zone (9).

14. Pressing element (1) according to any of the preceding claims, characterised in that in a coupled state, all press parts (2) of the pressing element (1) only border each other at facing edges (14) that extend in one direction.

15. Pressing element (1) according to any of the preceding claims, characterised in that the press parts (2) are provided at mounting edges (12) extending transversely to said facing edges (14) with gripping devices (20) for holding the press parts (2) together.

16. Pressing element (1) according to claims 12 and 15, characterised in that the press parts (2) comprise edge zones (10) extending along said panel structures (8) at said mounting edges (12) and that the gripping devices (20) are mounted to the mounting edges (12) in said edge zones (10).

17. Pressing element (1) according to any of claims 15-16, characterised in that a first said gripping device (20), provided at a first said press part (2) and asecond said gripping device (20), provided at a second said press part (2) are provided to border each other in the coupled position of the press parts (2) and are intercouplable.

18. Pressing element (1) according to claim 17, characterised in that the first gripping device (20) extends at a locking distance (Y) beyond the facing edge (14) of the first press part (2).

19. Pressing element (1) according to any of claims 15-18, characterised in that a said gripping device (20) is provided at the press parts (2) for intercoupling these press parts (2).

20. Pressing element (1) according to any of the preceding claims, characterised in that the pressing element (1) is provided with a pulling screw (21) for intercoupling the press parts (2), such that a distance between the press parts (2) is settable.

21. Pressing element (1) according to one of claims 17-19 and claim 20, characterised in that the pulling screw (21) is provided for intercoupling the first gripping device (20) and the second gripping device (20) for intercoupling the press parts (2).

22. Pressing element (1) according to any of the preceding claims, characterised in that the press parts (2) are welded together at the facing edges (14).

23. Pressing element (1) according to any of the preceding claims, characterised in that a said press part (2) comprises at least two partial press parts, each exhibiting part of the partial press surface (6) with part of the partial press structure (7) and in that preferably the at least two partial press parts are welded together to form the said press part (2).

24. Assembly of a pressing element (1) according to any of the preceding claims and a protection (22) for protecting a said facing edge (14) from deposition.

25. Assembly according to claim 24, characterised in that said protection (22) is designed as a plastic element which is detachably mountable to said facing edge (14).

26. Pressing machine, comprising a pressing element (1) according to any of claims 1-23.

27. Pressing machine, according to claim 26, characterised in that the pressing element (1) is a pressing element (1) according to any of claims 15-19 or 21 and that said pressing machine is provided with grippers (27) for gripping on the gripping devices (20) for coupling the press parts (2), which are for example movable away from each other and towards each other, for setting a distance between the press parts (2).

28. Pressing machine, according to claim 26 or 27, characterised in that the pressing machine comprises a base element against which the press parts (2) are mounted in the mounted position with a mounting surface (3) of the press parts (2) extending opposite to the press surface (4).

29. Method for manufacturing a pressing element (1) for manufacturing decorative panels, such as laminate panels, comprising a step a of providing at least two metal plates, a step b of providing said metal plates with a partial press surface (6), said partial press surface (6) comprising a partial press structure (7), and a step c of providing the metal plates couplable at facing edges (14), for forming press parts (2) which are couplable for forming said pressing element (1), the partial press surfaces (6) thereby together forming a press surface (4), extending substantially in a plane and the partial press structures (7) together forming a press structure (5), for forming a structure (26) on at least one said decorative panel, characterised in that step ccomprises providing the metal plates with retaining means (15) at the facing edges (14).

30. Method according to claim 29, characterised in that in step c, the metal plates are welded together at the facing edges (14), adding a weld as retaining means.

31. Method according to claim 30, characterised in that the method comprises a step d of removing the weld and a step e of rewelding the metal plates together at the facing edges (14), adding a new weld as retaining means.

32. Method according to any of claims 29 to 31, characterised in that in step a for at least one metal plate, at least two partial metal plates are provided, which are welded together for forming said metal plate and that in step b the partial metal plates are each provided with part of the partial press surface (6), comprising part of the partial press structure (7), wherein the parts of the partial press surface (6) together form the partial press surface (6).

33. Method according to claim 29 or 32, characterised in that in step c, the retaining means (15) are milled in facing side surfaces (13) of the press parts (2), which in a coupled position face each other.

34. Method according to claim 33, characterised in that in step c, at milling, a first said metal plate is provided with a tongue (17) and a second said metal plate is provided with a corresponding groove (18), wherein the tongue (17) is provided to engage in the groove (18) for securing said press parts (2) and in that the tongue (17) and the groove (18) are preferably milled at a fixed distance (Zi) from a partial mounting surface (11) of the plates, opposite to said partial press surface (6).

35. Method according to any of claims 33-34, characterised in that the method comprises a step f of providing the facing edge (14) of a said metal plate with a protection (22), after step c.

36. Method according to claim 34, characterised in that in step f, the said facing edge (14) is provided with a protective coating as said protection.

37. Method according to any of claims 35-36, characterised in that the method comprises a step g of providing the partial press surface (6) of said metal plate with a coating and a step h of removing said protection (22) from said facing edge (14).

38. Method according to any of claims 28-36, characterised in that this method is used for manufacturing a pressing element (1) having the features of one of claims 1-23.

39. Method for manufacturing decorative panels, such as laminate panels, wherein these laminate panels are provided with a structure (26) by means of a pressing operation, characterised in that a pressing element (1) according to any of claims 1-23 or obtained in accordance with one of claims 29-38 is used in the pressing operation.

40. Decorative panel, such as a laminate panel, obtained by means of a method according to claim 39.

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