DK172290B1 - Process for producing a curved wood fiber board, furniture board for use in the practice and wood fiber board made by the method. - Google Patents

Description

in DK 172290 B1

Process for producing a curved wood fiber board, furniture board for use in the practice and wood fiber board made by the method.

The present invention relates to a process for producing a curved wood fiberboard which is veneered on the front. Furthermore, the invention relates to a wooden board made of wood fiber and covered with veneer.

10 Fiberboard boards, such as particleboard, MDF boards and the like, are widely used in furniture manufacturing as such boards are easy to process and cheap as starting products. Furthermore, they are solid and have some advantageous properties over solid or laminated wood boards with respect to, among other things, mold stability under different temperature and humidity conditions, making wood fiber boards suitable for the manufacture of furniture. The sheet material is coated with a wood veneer and / or other surface covering and cut into shape, after which the sheet-pieces are assembled into a shelf, cabinet or speaker. This manufacturing method can be done in an automatic process, which makes it simple and no longer expensive, as well as ensuring a good protection of the furniture panels against moisture penetration.

25 The surface treatment and cutting of the plates can thus be done on the same process equipment, where a flat plate can be applied to both a surface treatment and a cutting.

In processing wood, especially wood fiber panels 30 for furniture manufacture, furniture manufacturers are also faced with having to make arch-shaped panels for furniture panels, for example for cabinet transmitters, cabinet doors and side panels in speaker cabinets. Such DK 172290 B1 2 panels are especially used in connection with more exclusive furniture design, however, the arch shape has proved to be a very costly manufacturing process that is far more difficult to handle. Various manufacturing methods are known for bending wooden boards, wherein a board such as wood fiber board, which may initially be cut with joints or the like, e.g. undergoes liquid or vapor treatments and / or heat effects.

In connection with these treatments or immediately after, the plate is bent into a molding tool, a binder is applied and held in tension for a given period of time until the plate is cured in its new form. These known manufacturing methods require extensive process equipment, which makes them a costly and time consuming process.

From i.a. DE 28 15 714 A1 and DE 43 40 049 A1 are also known methods, corresponding to the preamble of claim 1, for curvature of wood fiber boards by cutting slits 20 on one side of the board. The plates are then bent and molded, after which they can be surface treated in its final convex shape. This coating may consist of a grinding with subsequent paint, spray paint or the like.

When the sheet is shaped by one of these methods of bending, a surface treatment can be applied, such as a veneer coating. However, the surface treatment, such as polishing, varnishing and polishing the surface of the bent plate, is difficult to do in an automated process due to the curved surface (s) to which the surface is applied. Therefore, the surface treatment of the arcuate surface of such a plate is carried out manually, which is time consuming and the quality thereof depends on the craftsmanship available.

5 Characteristic of the various known methods of making arch-shaped panels in wood is that these are low-tech processes that are labor-intensive and with a very low degree of automation.

The object of the invention is, in this context, to provide a process for the manufacture of arcuate furniture plates which makes the production simpler and cheaper and suitable for implementation on an automated process equipment, and a furniture plate made using such a method.

The invention consists in a method of the kind set forth in the preamble of claim 1, wherein the veneer layer is surface treated in a flat state either before or after the performance of the slits in the back of the sheet.

In a method according to the invention, it is possible to treat the surface in the plane state of the plate and that the surface coating is not damaged during the subsequent curvature. Also, a very uniform and smooth curvature of the surface of the plate is obtained by the method of the invention. This means that sheets for arch-shaped furniture panels can be manufactured on the same processing plant used to make flat sheets for 30 pieces of furniture. Hereby, the same automation advantages, including both time saving and low production costs, are obtained in the manufacture of plate curved panels, which are obtained in the manufacture of flat panels.

DK 172290 B1 4

In addition, by a method according to the invention, it is possible to curb boards irrespective of their thickness, which makes the method extremely flexible in relation to furniture production, where different plate thicknesses are often used. Furthermore, it has been found possible with a method according to the invention to produce both convex and concave arcuate plates.

The invention further relates to a wood-fiber furniture board and veneer lined, where at least a portion of the backing which is desired to be curved is formed with groove-shaped slots of such a design that the plate can be curved.

The groove slots are, in a preferred embodiment, formed with a certain width at the bottom, and with a uniform depth, leaving an outer sheet of sheet under the veneer, the thickness of which corresponds substantially to the width of the grooves. This provides a very uniform and smooth curvature and avoids any "edges" due to 20 cracks in the veneer.

A further aspect of the invention is a wood fiber board made in accordance with the method of the invention wherein the curved plate is retained in the arcuate form by the plate being applied to a back support. The back support applied to the back of the sheet may in a preferred embodiment be a flexible sheet such as melamine paper applied by gluing. At the same time, a uniform inner surface of the furniture plate is obtained. By using a 30-piece furniture plate according to the invention for speaker cabinets, this embodiment of the rear support can also be used to compensate for any unacceptable sound reflections that might otherwise have arisen as a result of the rear slits. Furthermore, a backrest according to this embodiment can act as a moisture barrier, thereby preventing moisture from entering the plate. This is particularly advantageous in the production of furniture or furniture-5 panels to be exported from an area of temperate climate to areas with different climatic conditions such as subtropical or tropical climatic conditions.

In another embodiment, the backrest may comprise a matrix 10 or similar skeleton exhibiting sheaves the shape of which corresponds to the desired arc shape of the furniture plate (s). Hereby it is possible to curb the plate directly in connection with the structure around a matrix or similar skeletal structure for the furniture, which makes the assembly of a furniture plate according to the invention simple in a furniture panel. This kind of back support can also be used as a supplement to the application of a sheet piece.

Alternatively, the back support of a furniture plate 20 according to the invention may be formed by joining the furniture plate with a second plate, the plates at their backs being fixed to each other, so that the slats produced between the groove slots in the first furniture plate are engaged with groove slits. in the second plate, whereby the two plates act as back supports for each other.

Hereby an arcuate furniture panel can be obtained which is veneered on both sides, both plates being 30 identical in design. This can be attractive for furniture panels that are visible from both sides, as well as for freestanding panels or furniture. In addition, this embodiment can also be used as reinforcement of the furniture panel.

Another aspect of the invention is a piece of furniture which is formed in one or more sections with groove slots and is made with one or more cut-outs or openings for retrofitting of various types of fittings, such as speaker units, so that or the slotted sections make up 10 curved panel sides in the cabinet.

This means that several different sides included in the furniture, including the arc-shaped part (s) included, can be carried out in the same furniture plate, avoiding numerous 15 adjustments in production equipment. It is also achieved that even furniture with circular, oval or similar cross-sections can be manufactured without substantially increasing production costs.

Further, the furniture plate may be constructed on the reverse side with V-grooves formed parallel to the notes for forming corner edges when raising the furniture plate to the said tubular shape. Hereby it is further obtained that the furniture plate can be folded along the V-grooves, which makes it possible to make 25 furniture with polygonal cross-sectional shapes, one or more of the sides being arcuate.

The invention is described in more detail below with reference to the drawings, in which:

FIG. 1 is a plan view of a furniture plate according to the invention; FIG. 2 shows an arc-shaped furniture plate, FIG. 3-5 different embodiments of a furniture panel according to the invention; 6 is a top view of a furniture plate prepared for a plurality of arches; FIG. 7 is an end view of the same, and FIG. 8 shows the furniture plate shown in FIG. 6 and 7 raised to a high speaker cabinet.

In FIG. 1, there is shown a furniture plate according to the invention, comprising a wood fiber plate 1, which is coated on the front with veneer 2. In the back of the plate 1, groove slots 3 are made with a depth of slightly less than the thickness t of the plate. layers of the face of the plate 1 are intact, but of a suitably small thickness t 15 to make it flexible and flexible, thereby assuming a uniform curved shape on the outside.

The notes 3 are in the illustrated embodiment formed with a flat bottom and two parallel sides. The width b of the groove bottom 20 is of the same order as the thickness t of the outermost layer, thereby obtaining a satisfactory uniformity in the curvature of the veneer side. It is understood by the invention that in order to achieve a smooth and even curvature, it is important that the grooves 3 have the same depth, so that the layer thickness t is the same along the entire plate.

Thus, tests have shown, among other things, that a satisfactory smooth and uniform curvature of a veneer-coated MDF plate with a plate thickness T of 19 mm can be obtained.

In this case, the grooves in the back are made with a width b of 2 mm and with a depth such that the thickness of the outer layer of the veneer side is 2.5 mm and with a distance (slab width) of approx. 7 mm between each other.

DK 172290 B1 8

Of course, the notes may also have other shapes, for example with a rounded, semi-circular or concave bottom surface. However, it is important that the opening at the rear is sufficiently large in the planar state so that the slats 4 produced between the groove slots are not contacted by a convex curvature of the surface, see FIG. 2, or in each case contact between two neighboring cells is established only when the desired convex curvature is achieved. The veneer lining and milling of the grooves 3 are made in the plane state of the sheet, after which the sheet 1 is curved to the desired shape, which may be, for example, the shape shown in FIG. 2nd

15 In order to retain the furniture plate 1 in its arch shape, a rear support 5, 7, 1 'is applied.

In FIG. 3, an embodiment is shown in which the back support is a flexible sheet 5 such as a melamine paper glued to the back of the sheet after the curvature. This will expose the inner and untreated surface of the plate, which would otherwise be exposed to moisture, which can have very unfortunate consequences, as the shape stability and durability of the plate may be impaired. The glue 6 used for gluing the sheet to the back of the plate 1 binds the sheet 5 to the slats 4 and penetrates only a small distance into the grooves 3. Thus, only a modest amount of glue 6. If a further fixation is desired, the grooves 3 could be filled completely with the glue, but in this case it is preferred to use a sealant for the filling, since this is a cheaper solution.

DK 172290 B1 9 In fig. 4, the furniture plate 1 is attached to a skeleton structure 7, such as a matrix with a series of shavings 7, showing abutment surfaces with the same contour as the desired arc shape of the furniture panel. The furniture plate 1 is curved over and 5 glued on these shelves 7. Here, the adhesive 6 itself can also give some reinforcement of the panel.

In a variant of this embodiment, the furniture plate 1 is fixed in the desired curvature with a flexible sheet 5, 10 as shown in FIG. 3, whereupon the resulting furniture panel is fixed to a matrix as shown in FIG. 4th

In a third embodiment, the rear support is constituted by a plate 1 'made corresponding to the furniture plate 1, as shown in FIG. 5th

The two plates 1, 1 'are curved to the desired curvature, one to a concave and the other to a convex shape, after which they are preferably joined together by gluing at their backsides, both of which are formed with grooves 3, 3' and slats. 4, 4 '. The slats 4 'in the plate 1' enter and abut 20 against the grooves 3 in the furniture plate 1 and vice versa. The grooves 3, 3 'and thus the slats 4, 4' are geometrically shaped so that they can engage one another. In the notes 3, 3 'and the slats 4, 4' of the two plates 1, 1 ', prior to the assembly, glue (not shown) is applied which, in addition to bonding the plates 1, 1' together, can also act as filling - and thus stiffening - of the cavities within the grooves 3, 3 ', should be provided.

In the example shown in FIG. 5, both sheets 1, 1 'are coated with veneer 2, 2' on the outside. Hereby, a furniture panel according to this embodiment of the invention is obtained with DK 172290 B1 10 acceptable surface finish on both sides, which in some furniture designs, including furniture designs, will be advantageous. In a variant of the embodiment shown in FIG.

5, only one of the panels 1 is lined with 5 veneers 2. The other plate 1 'thus acts partly as a back support and partly as a reinforcement of the furniture panel.

FIG. 6 and 7 show a furniture plate 1 prepared with four sections 9, 10, 11, 12, corresponding to the four sides 10 of a speaker cabinet, as shown in FIG. 8. In the rear of the furniture plate, holes 13 are cut in the first section 9 in which loudspeaker units can be mounted, which in the second and fourth sections 10, 12 have grooves formed to produce arch-shaped panel sections, and 15 in the transition between sections 9 , 10, 11, 12, V grooves 8 are formed which correspond to the corner edges of the cabinet and have a depth almost equal to the thickness of the plate. By raising the plate 1 into a tubular shape, as shown in FIG. 8, the plate sections are folded around the V-grooves 20 8, which are thereby collapsed.

The invention is described herein in relation to a speaker cabinet, but it is recognized by the invention that both a method and a furniture board according to the invention can be used for the manufacture of other types of furniture, such as cabinets, tables, chairs and the like, in which a design is desired. or more arcuate panels.

Claims (11)

A method of producing a curved wood fiberboard (1), which is veneer-coated (2) on the front side, wherein at the rear of the board (1) in its plane state, at least that part (10, 12) of the board (1) which is desired to be curved, uniform parallel groove slots (3) are made in the longitudinal direction of the desired curvature, after which the plate (1) is bent in the transverse direction to a concave or convex arcuate configuration and fixed in this arcuate configuration, characterized by the veneer layer (2) being surface treated in a flat state either before or after the performance of the slits (3) in the back of the plate 15 (1). Method according to claim 1, characterized in that the groove-shaped slits (3) are formed with a certain width (b) at the bottom and at a uniform depth, leaving an outer sheet layer under the veneer, the thickness (t) of which is substantially corresponds to the width of the notes. Method according to claim 1 or 2, characterized in that the plate (1) is held in the arcuate shape by attaching to the back, preferably a backing piece (5,7,1 '). Method according to claims 1 - 3, characterized in that the plate (1) is curved to the arcuate configuration 3 30 over a matrix (7) which exhibits abutment surfaces whose contour 4 corresponds to the desired arcuate plate shape, and preferably the plate 5 (1) is mounted by gluing (6) to this matrix 6 (7). DK 172290 B1 12 Method according to claim 1 or 2, characterized in that the arcuate configuration of the plate (1) is maintained by its back side being joined to the back side of a correspondingly made plate (1 '), so that between the groove slots (3) slats (4) produced in one plate (1) are inserted into the groove slots (3 ') of the other plate (1'). Wooden fiber furniture board and lined with veneer for use in a method according to claims 1-5, characterized in that at least part of the back side which is desired to be curved is formed with uniform groove slots (3). of such a design that the plate (1) can be curved. 15 Furniture board according to claim 6, characterized in that the board (1) is provided with a sub-veneer between the surface veneer (2) and the wood fiber board (1). Wood fiber board made by carrying out the method according to claims 1-5, characterized in that the plate (1) is provided with a back support (1 ', 5,7) for retaining the desired curvature in the plate (1). Wooden fiber board according to claim 8, characterized in that the back support is a flexible sheet, such as melamine paper (5) applied by gluing (6). Wooden fiber board according to claim 8 or 9, characterized in that the back support is a matrix (7) or similar 3 skeleton, showing shavings whose shape corresponds to the 4 desired arc shape of the furniture plate (1). DK 172290 B1 13 Wooden fiber board (1) according to claim 8, characterized in that the rear support of the furniture plate is constituted by a second plate (1 ') and the plates (1,1') at their rear sides are fixed to each other such that between the groove-shaped slots (3) produced slats (4) in the first furniture plate (1) engage the groove slots (3 ') of the second plate (1'), whereby the two plates (1,1 ') act as back supports for each other . 10 Wooden fiberboard according to claims 8-11, characterized in that the furniture plate (1), which is formed in one or more sections with groove-shaped slots (3) and is made with one or more cut-outs (13) or openings for 15 retrofitting of fittings of various kinds, such as speaker units, are raised into a tubular form such that the slotted section (s) constitutes arcuate panel sides, in a speaker cabinet (10, 12). 1 Wood fiber board according to claim 12, characterized in that the furniture plate (1) on the back is further provided with V-grooves (8) formed in parallel with the grooves for forming corner edges when erecting the furniture plate (1), to the said tubular shape.