EP1719596A1 - Process for manufacturing a panel - Google Patents

Abstract

The method involves having a core consisting of a fiber material, preferably MDF- or HDF plate. One part of the panel (1) is cut by laser. The laser cut partly runs by a core (4) made of synthetic material. A layer (3) containing a panel (2) has the laser cut providing an edge. The laser cut runs by the layer and partly into the core. An independent claim is included for a floor board.

Description

The invention relates to a method for producing a panel of the type explained in the preamble of claim 1.

Panels are structural elements in the form of planks or planks that form a more or less closed surface, e.g. to a floor covering, a wall or other trim, furniture od. Like. Are composed. Panels can be in the form of a so-called laminate and then contain several layers of different materials. For a floor panel, e.g. the top surface in the finished floor covering formed by a wear layer that is both hard and resistant to wear and has decorative purposes to meet. As a further layer, a so-called core is provided, which is usually made of fiber materials, preferably of wood fiber materials, such as MDF boards or HDF boards.

In order to anchor adjacent panels together in the finished surface of a covering, at least two opposite sides of the panel are often provided with a connecting profile consisting of corresponding profile elements which can be connected to one another by angling and / or snap-fastening, as in the example WO94 / 26999 or in the WO97 / 47834 is described. So far, the panels are made with mechanical, cutting tools, such as saws or cutters. In this case, a plate corresponding to the multiple size of a panel is first provided, which contains the core and a further layer arranged thereon. Then the plate is separated into individual panel blanks. This is done by circular saw-like tools with a steel body and diamond-tipped cutting edges. Subsequently, the connection profile is formed, which in turn is done by a combination of different sawing and milling tools. The use of mechanical tools, in addition to the inevitable dust load and the relatively large cutting width, due to the thickness of the saw, even more disadvantages. These disadvantages will be explained briefly with reference to FIGS. 6 to 12 with reference to a floor panel. A mechanical tool, such as a saw blade or a milling cutter always exerts a certain resistance on an advanced workpiece, which increases with increasing feed rate always relevant. Currently, feed speeds of 200 m / min or more are used. Rotating tools have the disadvantage that there are high manufacturing tolerances both in the tool and in the drive motor. As a result, the intersecting line between adjacent panels may take a wavy configuration, as shown by the score line a in Fig. 6, middle illustration. If a panel has a hard surface layer and is cut with a rotary circular saw, the edge of the surface layer tends to fray, resulting in a fine white line at the joint line. This white line is caused by the friction between the tool and the surface layer and goes back to, for example, the wear-resistant coating material in the surface layer. This fine white line is shown in Fig. 7b. The speed with which the panels are passed through the machines is very high. Rotating tools have the disadvantage that the higher the speed, the greater the friction. A result of this is that not only the covering layer is frayed, but also an underlying second layer (a decorative layer), as shown for example in Fig. 8b. However, if the abutting edges of both panels are not close to each other, but cavities and spaces are formed therebetween, water may penetrate therein, as shown in FIG. As the core is mostly absorbent, the water is drawn into the core, causing the core to swell so that a surface layer or any other layer can lift off. Mechanical tools still need to be resharpened, for which the production plant must be shut down.

Mechanical tools, especially saws, have a certain thickness (about 2.5 mm), which can lead to a noticeable loss of material. Also, mechanical tools generate a high proportion of dust, which must be extracted and thus requires further investment costs.

When blanking panel blanks from a plate, the entire plate is passed through rotating rollers. Then the panel blanks are sawed off and in turn guided by guide rollers from the sawing machine. It is virtually impossible to do this without any horizontal displacement of the panels and the panel. There are many reasons for this, but it is mainly the combination of friction the saw blades and the guide and pressure rollers and the mechanical positioning of these components, which cause these small horizontal movements. This should be prevented in any case if the plate or the panels are provided with a geometric decoration. Figures 10 to 12 show such a decor, with Figure 10 showing how it is ideally made, and Figures 11 and 12 showing the problems of previous manufacture with rotary mechanical tools. In Fig. 10, the distances x and x 'on both sides of the joint line are equal to (x + x' = y '). Fig. 11 shows a possible result if the panels are not correctly positioned during sawing, as may happen in the prior art. Here, x + x 'are not equal, while y is still equal to y', but the collision line is in no way parallel to the edges. When laying such floor panels, the butt edge is not perfect and the decor patterns are misplaced.

In the case of directly abutting panels, even the smallest chipping and cracked location on the abutting edge, which can never be completely avoided with mechanical, rotating tools, still occurs. Furthermore, the friction of the tools at the cutting edges, and in particular at the wear layer leads to heating, whereby the wear layer, which usually consists of a plastic, can change color or in the structure. This also appears uncomfortable in the finished covering. These irregularities are exacerbated when the machining speed is increased for economical production.

The invention has for its object to provide a method for producing a panel that does not have the above-mentioned disadvantages.

The object is achieved by the method according to claim 1 and the panel according to claim 12.

It has been found that it is possible to completely eliminate the above-mentioned disadvantages when using a laser, at least for particularly stressed or exposed cuts. The laser cut produces neither dust nor a significant mechanical resistance, which could also push quickly fed workpieces off the track. A break of the edge does not occur and friction will not generated. Even the most serious disadvantage that hitherto opposed the use of lasers in the processing of fiber materials, ie the generation of heat and the resulting changes or burns on the cut surface, proves to be a decisive advantage when used for the production of panels, as a result Cut surfaces are virtually sealed. This is done on the one hand by melting of binders in the wood fiber material, such as melamine resin in HDF or MDF boards, and on the other hand by a kind of combustion or Verkolkung the cut surface that compacts their structure, but still remains visible in the connected state edge or visible cutting marks. Figures 6c, 7c, 8c and 10 each show perfect, almost invisible, butt lines as achievable with the present invention using a laser.

Advantageous developments of the invention can be found in the dependent claims.

Particularly exposed edges, such as, for example, the abutting edge in the area of the surface, which is directly visible in the finished covering and in which any irregularity occurs, are laser-cut by the method according to the invention.

However, it is also possible additionally or altematively to cut areas of the core with a laser in order to make it less absorbent at particularly exposed areas. If laser technology is used to cut a panel into a large number of panel blanks, the loss due to high cutting widths and the development of dust can also be decisively reduced here, and the cost-effectiveness can be increased.

If the natural sealing provided by the laser used for cutting is insufficient, then the laser can be set or selected specifically for this task.

Fig. 1

eine perspektivische, schematische Darstellung eines Teils eines aus Paneelen zusammengesetzten Belags,

Fig. 2

eine vergrößerte Teildarstellung eines ersten Verbindungselements eines Verbindungsprofils,

Fig. 3

eine vergrößerte Teildarstellung des korrespondierenden Verbindungselements des Verbindungsprofils,

Fig. 4

eine schematische Darstellung zum Durchführen des erfindungsgemäßen Verfahrens,

Fig. 5

eine schematische Darstellung verschiedener Verfahrensschritte zum Durchführen des erfindungsgemäßen Verfahrens, und

Fig. 6-12

schematische Darstellungen der Nachteile des Standes der Technik und der Vorteile der vorliegenden Erfindung.

An embodiment of the invention will be explained in more detail with reference to the drawings. Show it:

Fig. 1

a perspective, schematic representation of a part of a panel composed of panels,

Fig. 2

an enlarged partial view of a first connecting element of a connection profile,

Fig. 3

an enlarged partial view of the corresponding connecting element of the connection profile,

Fig. 4

a schematic representation for carrying out the method according to the invention,

Fig. 5

a schematic representation of various process steps for performing the method according to the invention, and

Fig. 6-12

schematic representations of the disadvantages of the prior art and the advantages of the present invention.

Fig. 1 shows a perspective, schematic representation of a portion of a covering 1, which is composed of a plurality of individual, preferably identical, board or plank-shaped panels 2, wherein only two panels 2a and 2b are shown. In the illustrated embodiment, the panels 2a, 2b are identical, so that only one of the panels is described representative.

Each panel 2 consists in the illustrated embodiment of a so-called laminate, that is, it contains several layers. In the illustrated embodiment, the panel includes a surface layer 3 and a core 4. The surface layer 3 forms the top 3a of the panel, ie the utility and visible surface. In floor panels, the surface layer 3 is formed as a wear layer and usually contains a hard wear layer, such as melamine resin, and a decorative layer, usually made of wood decor. However, the tread layer may consist of only one layer that performs both functions.

The core 4 forms a plate of fiber material, such as a mineral, glass, or preferably a wood fiber material, in particular a chipboard or, preferably, an MDF board (medium-density board) or an HDF board (high-density plate). The two latter plates are wood fiber boards and consist of pressed and bonded with binder, usually melamine resin, or other glues Spanstaub. Compared to pure chipboard, from shredded and pressed wood chips bound with binder, wood fiber boards have the advantage that they have a fine, almost homogeneous structure and can be easily profiled at their edges without tearing out.

In the illustrated embodiment, the surface layer 3 is attached directly to the core 4 and other layers are not drawn. In a floor panel 2, however, the usual additional layers may be provided, so for example, a footfall sound insulation, a heating surface, a balancing soil layer or the like. Included.

For a preferred glue-free installation of the panels 2, each panel 2 is provided on at least two opposite, transverse to the surface 3a extending side surfaces in the illustrated embodiment, the long side surfaces of the panels 2, with a connecting profile 5, which contains two corresponding and interlocking connecting elements 5a and 5b , However, each panel 2 may also be provided on opposite short sides with a connecting profile of corresponding connecting elements. The invention is also applicable to panels without connecting profile.

2 and 3, a preferred form of a connection profile 5 with two corresponding connection elements 5a, 5b is shown, wherein the connection element 5a is provided on each one long side of the panel 2 and the connection element 5b on the opposite long side of each panel 2. The connecting elements 5a, 5b contain the usual interlocking projections and depressions, which are pushed together in a known manner during installation and / or rotated and / or locked together and in the finished covering 1 without the use of glue for locking the panel 2 against each other all Take care of directions. Such connection profiles are known in large numbers, so that they need not be explained further below.

On each of the panels 2 is preferably formed around a joint edge 6, with the adjacent panels 2a, 2b abut each other to form a appearing on the surface 3a of the joint line 7 (FIG.

In the illustrated embodiment, the abutting edge 6 is provided on a laterally projecting projection 8, which extends over the surface layer 3 over part of the panel thickness into the core 4 and extends to the top 3a. The projection 8 is bounded outwardly by a boundary surface 6a, in which the abutting edge 6 is located and which encloses a right angle to the top surface 3a.

When laying the panels 2a, 2b to the floor covering 1, the boundary surfaces 6a adjacent panels abut each other. In order to produce in this way the most uniform and almost invisible joint line 7, the abutting edge 6 and possibly the boundary surface 6a must be worked very accurately.

This is achieved by the method according to the invention.

When manufacturing the panels 2, first, as shown in FIG. 4, the usual plate 10 is assembled from the laminate materials. In particular, the plate 10 includes the surface layer 3 and the core 4. This plate 10 is, as shown in FIG. 4, conveyed in a conventional manner by pairs of rollers 11 which exert a certain pressure on the plate 10, rotate, and thereby the plate 10th gently and continuously and at high speed. However, other suitable conveyors are also useful.

The plate 10 is separated during conveyance by dividing lines 9 into individual panel blanks 10a. Deviating from the prior art, however, this is done with the aid of a laser device 12 shown only schematically with a plurality of spaced apart the width of the panel blanks 10 a adjacent laser conventional type. Preferably, a laser with 5 KW total power is used and operated with a cutting capacity of 200 mW. However, the cutting performance of the laser can, as will be explained below, be changed according to the desired results or be adjustable. The width of the dividing line 9 produced by the laser is only a few tenths of a millimeter, preferably between 0.2 and 0.3 mm (compared to about 2.5 mm in conventional saws).

The plate 10 is guided by the rollers 11 and under the laser 12 in an orientation in which the surface layer 3 upwards. facing the laser 12, is aligned.

The lasers completely cut plate 10 in one pass through rollers 11 into the individual panel blanks 10a; with minimal blending between the blanks, resulting in excellent material utilization. Dust does not occur, so that the provisions for Staubentfemung, which are necessary with the mechanical tool, can be omitted. The cutting speed is high. Nevertheless, neither friction, which could alter the surface layer 3, nor breaks, nor uneven mechanical escapement, through which vibrations may build up, which are responsible for oblique or wavy cuts in the prior art. The blanks 10a are thus produced with optimum quality.

The use of lasers is furthermore particularly expedient in the production of the abutting edge 6 in the region of the connection profile 5, as will be explained in more detail with reference to FIG. 5. 5 shows on the left side the production of the connecting element 5b of the connecting profile 5 and on the right side the production of the connecting element 5a of the connecting profile 5. Circular-guided arrows indicate that in each case mechanically rotating tools are used for this production step. Thus, for example, a mechanical milling cutter or saw 13 is used in step A, while in the subsequent step B milling cutters, for example face or profile milling cutters 15 are used.

According to the invention, in the course of process steps A and B at a location which contains the later abutment edge 6, a piece of residual material 16 is attached to both connecting elements 5a, 5b left. The residual piece of material 16 may have any suitable shape, as it results from the process.

This remnant piece 16 is cut off in method step C with the aid of a laser 12, wherein the laser beam for forming the abutting edge 6 extends through the surface layer 3. Preferably, the laser beam also extends into the adjacent region of the core 4 for forming the boundary surface 6a. Optionally, you can work with reflector plates or other suitable measures to ensure that already completed areas of the connecting elements 5a, 5b are not damaged or destroyed.

The remnant piece 16 is further cut off so that the projection 8 shown in Figs. 2 and 3 remains.

By using the laser 12, an exact, exactly rectilinear abutting edge 6 is produced here, which produces an almost invisible dividing line 7 in the finished covering 1. Furthermore, the areas of the core adjoining the surface layer 3 are influenced by the laser in such a way that the water absorption capacity there is greatly reduced. In particular, this is done by melting the binder in the fiber material, so in particular the melamine in the HDF or MDF plates and optionally by a slight onset by the heat of the laser. This prevents the ingress of water in two ways. Once the dividing line 7 is so thin that water can hardly penetrate due to its surface tension, but still penetrates water, so it can not be absorbed by the laser cut areas so that swelling of the core 4 by raising the surface layer 3 does not take place can.

Subsequently, the connecting elements in step D are completed in the usual way by rotating mechanical tools 17.

Another application for the use of lasers in the manufacture of panels is in the surface treatment. Thus, the surface 3a, for example, with the indicated in Fig. 1 incisions 18 for decorative or technical functional purposes be provided. The cuts 18 can be made so wide that they are clearly visible. Here, too, a breaking of the edges or a deviation from the ideal position is avoided, and achieved an improved water resistance.

In a modification of the described and illustrated embodiment, other cuts than the dividing line, the abutting edge of the incisions and the boundary surface can be generated by laser, depending on where and at which cutting work the advantages described above should be achieved. The invention can also be used in panels with other connection profiles. As the material of the core other wood fiber materials can be used. Although the invention is particularly suitable for producing floor panels having a core of wood fiber materials and a surface layer formed as a wear layer, other panels, e.g. for covering a wall or the like or for furniture. The panels may have more than the described layers or may be made of only one material, e.g. a wood-based material, with or without surface treatment.

Claims (12)

A method for producing a panel (2), wherein the panel (2) has a core (4) of a fiber material, preferably having a MDF or HDF board, characterized in that at least one cut (6, 6a, 9) on the panel (2) is laser cut. A method according to claim 1, characterized in that the laser cut (6a, 9) extends at least partially through the core (4) made of fiber material. Method according to claim 1 or 2, characterized in that, in the case of a panel (2) containing a surface layer (3), the laser cut extends to form an abutment edge (6) through the surface layer (3). A method according to claim 3, characterized in that the laser cut (6a) extends through the surface layer (3) and at least partially into the core (4). Method according to one of claims 1 to 4, characterized in that on one side of the panel (2) a projection (8) is formed, which contains a cut by laser abutting edge (6). Method according to one of claims 1 to 5, characterized in that when producing a connection profile on one side of the panel (2) a remnant piece (16) of the material of the core (4) remains on the core (4) and is then cut off with a laser , A method according to claim 6, characterized in that the remnant piece (16) at the transition from a surface layer (3) to the core (4) remains. Method according to one of Claims 1 to 7, characterized in that a plate (10) is produced from the core (4) and a surface layer (3) connected to the core (4), and a panel blank (10a) is produced by laser ( 12) is cut off from the plate (10). A method according to claim 8, characterized in that for cutting the plate (10) in a plurality of panel blanks (10a) a plurality of juxtaposed and in the width of the panel blanks (10a) spaced from each other laser (12) are provided. Method according to one of claims 1 to 9, characterized in that the power of the laser is adjusted to the material of the core (4), that the laser cut offers a relation to the core material improved resistance to the ingress of water. Method according to one of claims 1 to 10, characterized in that a surface (3a) of the panel (2) is processed by laser. Floor panel (2), having a wear layer (3) and a core (4) of a wood fiber material, preferably an MDF or HDF board, characterized by a generated by a laser cut edge (6).

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