EP2329932B1 - Method for producing panels, in particular floor panels - Google Patents

Description

The invention relates to a method for producing panels, in particular floor panels, according to the preamble of claim 1. Such a method is known from WO 97/13626 A known.

In the context of the present invention, a panel is a multi-layer board with a wooden material carrier layer as a lignocellulose-containing material, for example a chipboard, OSB board or fiberboard (MDF, HDF board, for example), the carrier layer at least on its upper side, optionally also on its underside, with a cover layer which is a layer with a directly applied decorative printing with a seal or a directly applied lacquer, resin, laminate, laminate or veneer, wherein at least the top side cover layer usually forms a decorative layer. Such a panel also has a profile in the edge region, which corresponds with a corresponding one Profile of a neighboring plate interacting with a laying composite. Corresponding tongue and groove profiles are produced on the multilayer plate by means of a special milling head of a processing machine.

The topsheet of a panel as made in accordance with the present invention may be formed in various ways. For example, this may be applied as a direct print on the carrier layer and then sealed by a transparent lacquer or a synthetic resin layer or it is in the cover layer to a resin impregnated with decorative paper which is pressed directly to the carrier layer. However, the cover layer can also be made of a laminate, that is to say a structure composed of several resin-impregnated paper layers which are joined together under high pressure, the upper layer being a decorative layer and optionally a transparent overlay paper, or a veneer, ie a relatively thin wood sheet become.

Several panels arranged in a composite can form a floor or a wall or ceiling paneling. In particular, when used as floor panels, it is important that the panels, especially the profiles, are made as accurately as possible and with a high dimensional stability, otherwise the panels can not be laid properly to a laminar composite and early damage to the flooring Can be a consequence. Furthermore, increased noise can occur due to creaking noises and / or damage to the floor panels, in particular in the edge region.

Especially in the case of the "forming" processing steps separating or cutting to length (dividing Machining), stripping (abrasive machining) and milling (machining), it is therefore precisely in the processing of floor panels of the type described above to a high degree of precision. Thus, for example, the laminate layer provided with hard particles should be intentionally destroyed by the stripping, where in a subsequent processing step a separating cut takes place or a milling tool removes material. The tools used for this purpose must currently be of very high quality in order to achieve acceptable tool life. Therefore, only expensive tool cutting tools made of polycrystalline diamond (PKB tools) are currently used. In particular, when milling the upper contact surfaces of the profiles may also lead to breakouts of the edges.

It is known from the prior art that not all fibers are cleanly separated by the machining of wood materials, especially when sanding wood fiber boards, but are partially torn or pressed. In the subsequent application of primers, paints or powder coatings and adhesives, the material surface is wetted with water or solvent. As a result, the fibers straighten up again and require repeated sanding or filling of the surface. In addition, the coating materials are increasingly absorbed, which increases the required order quantity and deteriorates the quality. This effect leads to high costs for laminate flooring with high production costs and costly intermediate steps in the coating. For this reason it is from the WO 2009/094792 A1 known, the surfaces of wood-based panels by so-called Thermo flattening means pretreat heat-treated rolls in such a way that the surfaces can be optimally coated without intermediate sanding and puttying. In this way, in the case of floor panels, attempts are made to achieve a high dimensional stability, also in the edge area. However, the thermal quenching means an additional step and does not prevent the emergence of eruptions in the area of the surface to be machined in the dividing, abrading or machining a wood-based panel in a satisfactory manner.

From the food industry, textile industry and automotive industry, it is also known to stimulate certain processing tools such as cutting or drilling tools in the ultrasonic field. The excitation takes place by means of a sound transducer and possibly a so-called sonotrode, which sets the tools in resonance vibrations by introducing high-frequency mechanical vibrations. The transducers and sonotrodes make the connection from a high frequency generator (ultrasonic generator) to the processing tool.

It is the object of the present invention to develop a method for producing panels, in particular floor panels, of the type mentioned in such a way that a higher dimensional accuracy and precision is achieved in the machining surface treatment of the carrier layer in the edge region, the panels.

The previously derived and indicated object is according to the present invention in a Method for producing panels, in particular floor panels, according to claim 1.

By translational oscillating motion in the ultrasonic range is transmitted to the respective machining tool in the shaping machining, for example, in the below-described zerteilenden machining, abrading machining and / or machining, the respective processing step with respect to the prior art significantly increased dimensional accuracy and precision are performed. Surprisingly, it has been shown in the technical field of the production of panels, in particular floor panels, that by supporting the machining process by means of an ultrasonic oscillatory movement, which preferably takes place in the direction of the longitudinal central axis or axis of rotation of the machining tool and / or perpendicular to the machining surface, reduce tool wear and correspondingly increase the service lives of the tools. In addition, compared to the prior art significantly lower feed force and a lower torque of the tool when performing the shaping processing is necessary. As a result, the risk of bleeding the tools is significantly reduced, which ultimately the precision and dimensional accuracy, for example, the profile to be generated benefits.

According to one embodiment of the method according to the invention, instead of just a single ultrasound-assisted machining tool as described above, a plurality of such machining tools may also be provided. Thus, according to this embodiment, a plurality of processing tools, in particular independently of each other, perform a shaping processing, under the action of a translatory oscillating movement in the ultrasonic range, to the respective processing tool. It is therefore conceivable that in the manufacture of panels, in particular floor panels, a processing station with a plurality of processing tools of the type described above and / or several successive processing stations are provided with at least one such processing tool. In principle, it is also conceivable that a plurality of such processing tools perform the respectively corresponding shaping machining on the multilayer plate at the same time, whereby the data transferred from the individual processing tools to the workpiece Ultrasonic vibration movements due to the special material of the carrier layer, not significantly affect each other.

In particular, it can be of crucial importance, especially in the production of panels, in particular floor panels, that the various types of processing, that is to say dividing and machining, are carried out in a specific sequence in order to achieve an optimum result. This will be explained in more detail below.

In the case of a further dividing processing, this can be done for example by means of a blade, it can be provided that the dividing processing cuts through the multilayer plate over its entire thickness. However, it can also be provided that only the cover layer, for example the laminate, is severed by the dividing processing. The step of severing the multilayer plate over its entire thickness is then when individual plates are to be produced from the multilayer plate, which correspond in dimensions, for example, already the dimensions of the finished panels. The severing of only the cover layer by a dividing processing, for example, makes sense if in the edge region of the multilayer plate, a subsequent machining is to be done by means of a milling head through which a tongue and / or tongue profile is generated. In this case, in the area in which the profile is to be produced, first the cover layer clean are severed, so that the set for profile generation on the workpiece milling head, when it comes into contact with the cover layer in the edge region, can not damage the top layer in the remaining region of the cover layer, ie beyond the previous separation section. The later visible in the finished panel edge of the top layer is therefore not formed by the milling head or the machining, but previously by the more precise zerteilende processing.

The severing of only the top layer can be done instead of a zerteilende processing by a removing machining. Thus, the abrading processing, which in principle can be done by means of a grinding head, the multilayer plate are at least partially stripped, wherein in the area to be stripped of the multilayer plate preferably the cover layer is removed over its entire thickness. Even such an abrasive machining leads to a more precise edge shape in the region of the cover layer in comparison to the case that the edge would be produced directly by the machining tool, for example the milling head.

Basically, it is also conceivable that the shaping processing of the cover layer in the production of an edge profile waiving a preceding dividing and / or abtragende processing, as by the support of the cutting machining tool, for example, the milling head, by the ultrasonic oscillating movement and the machining tool with lower forces and moments and thus can be performed with greater precision, which increases the dimensional accuracy. In principle, it is also conceivable that the abrasive machining to increase the precision of the dividing processing, in particular the severing of only the top layer precedes. In this way it is possible, first with a dividing machining tool, such as a blade to sever the top layer with particularly great precision, then next to the separating cut in a transition region an abrasive machining, for example by means of a grinding head, which may be less accurate than the dividing machining tool but more precise than a machining tool is to perform and finally perform a machining, for example by means of a milling head, which may be the least accurate of all three types of tools, the production of a profile. In this case, the cutting machining tool, for example the milling head, can then be moved into the transition area, without the risk that the milling head unintentionally comes into contact with the already cleanly shaped edge of the cover layer.

Finally, leg machining, as already indicated, by this on the support layer of the edge of the multilayer plate, a tongue and / or groove profile, are produced. As described, preferably the cutting machining is preceded by the dividing processing, in particular the severing of only the cover layer, and / or the abrading processing, in particular the removal of the cover layer over its entire thickness in a subregion of the multilayer plate. Basically, the machining, for example, for profile production, and the preceded by dividing processing in the form of severing the multilayer board over its entire thickness.

The machining or all of the above-described shaping machining methods can be assisted in the production of panels, in particular floor panels, by the described translatory oscillation movement in the ultrasound region, which acts on the machining tool. In this case, according to one embodiment of the method according to the invention, the translatory oscillatory motion is performed at a frequency which is in a range of 15 to 70 kHz, preferably 20 to 40 kHz, more preferably 20 to 35 kHz. These frequency ranges have proven to be particularly suitable in the processing of multilayer plates having a carrier layer of a lignocellulosic material.

In one device, an AC voltage generated by a drive, in particular a high-frequency generator, in a sound transducer, also called a converter, is connected to a ceramic or quartz crystal plate. The plate thereby performs vibrations in a certain frequency, which are particularly strong at resonance. The amplitude of the oscillations can be enhanced by a sonotrode arranged between the sound transducer and the machining tool, also called transformation piece or reinforcing trunk, if necessary.

Even with a device several processing tools can be provided. According to one embodiment, a plurality of processing tools are provided, which are configured for shaping a multilayer plate with a carrier layer of a wood material, and with a top layer connected to the carrier layer cover layer, in particular a laminate, laminate or veneer, and in particular independently operable.

Such a device has the advantage that for the first time in the manufacture of panels, in particular floor panels, in which a multi-layer plate is provided with at least one layer of a lignocellulosic material, a very high precision and thus dimensional accuracy in the processing of the edges is achieved and in this way no additional pretreatment steps such as thermal quenching or post-treatment steps such as grinding or trowelling are necessary. The panel obtained by the method according to the invention can thus be produced in a particularly effective manner and in a high-quality state.

According to one embodiment of an apparatus, the drive for the respective sound transducer on a high-frequency generator, wherein the high-frequency generator is configured such that the translatory oscillatory motion is carried out at a frequency in a range of 15 to 70 kHz, preferably from 20 to 40 kHz, particularly preferably from 20 to 35 kHz. Especially in the processing of panels, which thus inevitably have at least one lignocellulosic layer, it has been found that a particularly good result of the shaping processing is achieved when the oscillating movement is performed in one of said frequency ranges. The same applies to the case where the high-frequency generator is configured such that the amplitude of the oscillatory movement is in a range from 2 to 100 μm, preferably from 4 to 50 μm, particularly preferably from 6 to 25 μm. Especially these frequencies and / or amplitudes lead in panels to a particularly low risk of material eruptions in the edge region.

The sonotrode is according to another embodiment, a moving, in particular rotating, or a fixed sonotrode. A rotating sonotrode is useful if this vibrated with the sonotrode Machining tool is also a rotating tool, such as a grinding head or milling head. A fixed sonotrode can be used when the machining tool is also a stationary tool, which, for example, after being brought into contact with the surface of the panel, is moved substantially in the direction of the plane of the plate, such as a blade for cutting the plate material.

As indicated, the at least one machining tool is a machining tool, in particular a milling head. Further shaping machining tools are a dividing machining tool, in particular a blade, and / or a removing machining tool, in particular a grinding head. Especially with the mentioned

Machining tools executable machining operations are very precise, since they have an immediate impact on the final shape of the panel in the edge area. Precision and dimensional accuracy are particularly important in the edge area, since noise and damage can occur, especially in the case of floor panels, due to the stress caused by inaccurately worked edges. With the help of the ultrasonic oscillating movement, which acts on the machining tool, however, precisely these machining steps can be carried out particularly precisely.

Fig. 1a) und b)

ein erstes Ausführungsbeispiel einer Vorrichtung zur Herstellung von Paneelen,

Fig. 2

ein zweites Ausführungsbeispiel einer Vorrichtung zur Herstellung von Paneelen und

Fig. 3

ein drittes Ausführungsbeispiel einer Vorrichtung zur Herstellung von Paneelen.

In the drawing shows:

Fig. 1a) and b)

A first embodiment of a device for producing panels,

Fig. 2

A second embodiment of an apparatus for producing panels and

Fig. 3

A third embodiment of a device for the production of panels.

The FIGS. 1 to 3 all schematically illustrate a device 5 for the production of floor panels during a special processing step. Fig. 1b ) is a side view of the embodiment in Fig. 1a ). The Views in the Figures 2 and 3 correspond in turn to the view in Fig. 1a ).

During the illustrated processing, a multilayer plate 2 initially provided with a carrier layer 2a of a wood material, here a high-density fiberboard (HDF plate), and with a top layer 2b connected to the carrier layer 2a from a layer with a sealed decorative print with a processing tool 3 and 3 'and 3 ", respectively, wherein the machining tool moves relative to the multi-layered plate 2 in such a way that a shaping operation, namely a dividing machining (FIG. Fig. 1 ), an ablation ( Fig. 2 ) and a machining ( Fig. 3 ), the multilayer plate 2 takes place.

In addition to the shaping of the machining significantly effecting movement of the machining tool 3 or 3 'or 3 "is still a independent oscillatory movement, in the FIGS. 1 to 3 symbolized by a double arrow X, such that the decisive for the shaping processing (main) movement and the oscillating motion overlap and at the same time on the workpiece, that is, the multi-layer plate 2, act, thereby causing a particularly precise processing. The oscillatory movement X is carried out at a frequency of 20 to 40 kHz, ie in the ultrasonic range, and an amplitude in the range of 6 to 25 microns, wherein the oscillating movement is perpendicular to the plate plane and perpendicular to the actual movement of the machining tool. The latter movement is at the in Fig. 1 a cutting movement parallel to the plane of the plate shown in FIG Fig. 2 shown eroding processing and also in the Fig. 3 shown machining a rotation in a plane parallel to the plane of the plate.

In order to carry out the above-described forming processing, the device 5 as stated has a processing tool 3 or 3 'or 3 ", which is specially configured for shaping a multilayer plate 2 with a carrier layer of a lignocellulosic material and having a top side Cover layer connected to the carrier layer, which here consists of a layer with decorative printing.

Furthermore, the device 5 has a sound transducer 8 and a sonotrode 6, which is connected to the machining tool 3 or 3 'or 3 "in such a way that, as explained above, a translatory oscillatory movement in the ultrasonic range is transmitted to the machining tool and coincides superimposed on the actual movement of the machining tool required for shaping machining.

The sound transducer 8 has as a drive 7 to a high-frequency generator 7a, which is connected by means of a transmission line 7b to the transducer 8. The high-frequency generator 7a is configured so that it causes in the machining tool 3 or 3 'or 3 ", an ultrasonic oscillatory movement at least in the range of 20 to 40 kHz with an amplitude in the range of 6 to 25 microns.

The FIGS. 1 to 3 differ in the respective editing tool. According to Fig. 1a ) and b) the processing tool 3 is a dividing one Machining tool 3 in the form of a blade. The sonotrode 6 is in this case a fixed sonotrode 6. The dividing machining tool 3 performs a dividing machining, such that the multilayer plate 2 is cut through its entire thickness and two individual panels 1a and 1b are formed.

In the embodiment according to Fig. 2 If the machining tool 3 'is an abrasive machining tool 3' in the form of a rotating grinding head. In this case, the sonotrode 6 is a moving, in this case a rotating, sonotrode 6. The removing machining tool 3 'carries out a removing machining, wherein the multilayer plate 2 is stripped so that the cover layer 2b is over in the area to be stripped their entire thickness is removed.

Finally, it is in the machining tool 3 "according to the embodiment in Fig. 3 Again, the sonotrode 6 is a rotating sonotrode 6. The cutting tool 3 "performs a machining operation on the edge 2c of the multilayer plate 2, thereby forming a part of a Groove and / or spring profiles 4 is made, namely, more precisely, the upper contact surface and a part of the end face of the profile. 4

The in the FIGS. 1 to 3 Devices 5 shown can also be individual processing stations of a higher-level apparatus for producing panels 1, 1a, 1b, wherein the dividing processing tool 3 according to FIG Fig. 1 the abrasive machining tool 3 'according to Fig. 2 can be upstream and the latter in turn the machining tool 3 "according to Fig. 3 can be upstream.

Claims (7)

1. A method for manufacturing panels (1, 1a, 1b), in particular floor panels, in which the following steps are performed:

   - Providing a multilayer plate (2) with a carrier layer (2a) composed of wood based material as a lignocellulose-containing material, and with a top layer (2b) joined on the upper side with the carrier layer (2a),

   - Bringing the multilayer plate (2) into contact with at least one machining tool (3, 3', 3"), and

   - Moving the at least one machining tool (3, 3', 3") relative to the multilayer plate (2) so that a machine shaping of the multilayer plate (2) takes place,
   wherein the machine shaping takes place as a translational vibrating movement (X) acts on the machining tool (3, 3', 3"),
   wherein the translational movement (X) takes place in the ultrasound range, wherein the top layer (2b) is a layer having a directly applied decorative print with a seal or a directly applied lacquer, synthetic resin, laminate, coating material or veneer,
   characterized in that the translational vibrating movement (X) is performed at an amplitude lying in a range of 2 to 100 µm, and wherein the machine shaping is a machine cutting of the carrier layer (2a), as a result of which a groove and/or tongue profile (4) is fabricated on the edge (2c) of the multilayer plate (2).
2. The method according to claim 1, characterized in that several machining tools (3, 3', 3"), in particular independently of each other, perform a machine shaping while a translational vibrating movement (X) in the ultrasound range acts on the respective machining tool (3, 3', 3").
3. The method according to claim 2, characterized in that another machine shaping is a distributive machining, by means of which in particular the multilayer plate (2) is cut over its entire thickness or only the top layer (2b) is cut.
4. The method according to claim 2 or 3, characterized in that another machine shaping is an abrasive machining, in which the multilayer plate (2) is preferably at least partially stripped, wherein the top layer (2b) is especially preferably removed over its entire thickness in the region of the multilayer plate (2) to be stripped, wherein the abrasive machining in particular is preceded by the distributive machining, preferably by cutting through only the top layer (2b).
5. The method according to claim 3 or 4, characterized in that the machine cutting is preceded by the distributive machining, preferably by cutting through only the top layer or cutting through the multilayer plate (2) over its entire thickness.
6. The method according to claim 4 or 5 when dependent on claim 4, characterized in that the machine cutting is preceded by the abrasive machining, in particular by removing the top layer (2b) over its entire thickness in a partial region of the multilayer plate (2).
7. The method according to one of the preceding claims, characterized in that the translational vibrating movement (X) is performed at a frequency lying in a range of 15 to 70 kHz, preferably of 20 to 40 kHz, especially preferably of 20 to 35 kHz, and/or at an amplitude lying in a range of 4 to 50 µm, preferably of 6 to 25 µm.

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