Field of the Invention

This invention relates to a method for providing a laminated board, and a method for manufacturing a furniture element. Moreover, this invention relates to a laminated board and a furniture element comprising such laminated board.

Technical Background

In furniture manufacturing, low weight elements are widely used. Such elements usually consist of a hollow body enclosing a lightweight filling material. The hollow body is covered by a thin film for increasing the aesthetic impression as well as for providing a protective coating for the element. Such low weight elements can be used as construction elements, door panels, and a large amount of furniture elements. Especially in case of home interior applications, heavy demands are made on the thin film. Any damage or degeneration will deteriorate the quality of the low weight element. Consequently, a number of manufacturing methods for such low weight elements have been presented. The European patent EP 1,492,663 describes a hollow sandwich panel having a body clad externally by sheets, each sheet being composed of a structural layer and of an external lamina that has a predominantly aesthetic function. The sheets comprise contoured incisions at which folds are formed in order to make said sheets follow the discontinuities of the body and/or other discontinuities, said incisions associated with convex folds being formed on the side of said layer through its entire depth. The external lamina is used as a hinge when the sheets are folded.

The hollow sandwich panel results in folding edges having a very uneven surface, or even cracked edges. This affects the quality of the hollow sandwich panel severely. Another problem with the hollow sandwich panel is that the folding edges must be grinded, which result in an additional manufacturing step, thus increasing the manufacturing costs.

Also, the manufacturing method of the hollow sandwich panel according to EP 1,492,663 requires the application of an auxiliary tape for enabling and ensuring that the edges of the final product are held together. This is due to the fact that the V-shaped incision, allowing the folding of the sheet, most certainly damages the lamina, and that the folding of the sheet stretches - and thereby strains - the lamina. Hence, an improved low weight element for furniture manufacturing would be advantageous, as well as an improved method for manufacturing such low weight element.

Summary of the Invention

Accordingly, the present invention preferably seeks to mitigate, alleviate or eliminate one or more of the above-identified deficiencies in the art and disadvantages singly or in any combination and solves at least the above-mentioned problems by providing a method and a device according to the appended patent claims. An object according to some embodiments is to provide a method and a device for providing a low weight element from a minimum of raw material.

Another object according to some embodiments is to provide a method and a device without need for additional surface treatment.

Yet another object according to some embodiments is to provide a continuous manufacturing process of a low weight element.

According to an aspect, a method for providing a laminated board material comprising a board material having a first side and a second side is provided. The method comprises arranging a first longitudinal groove on said first side of the board material, applying a laminating foil on said first side of said board material, said laminating foil is covering said first groove, and arranging a second longitudinal groove on said second side of said board material, said second groove is extending through said board material to connect with said first groove. This is advantageous in that the risk of damaging the laminating foil is decreased, since the second groove does not need to extend all the way to the laminating foil but only to the first groove. According to another aspect, a method for manufacturing a furniture element is provided. The method comprises the method for providing a laminated board material according to some embodiments, arranging a supporting structure at the second side of said board material by means of a fastening means, and folding said board material along a first and second set of said first and second grooves, respectively, such that the supporting structure is enclosed within said board material. This is advantageous in that the furniture element will have two sides and two edges readily laminated with a foil without the need for additional surface treatment.

According to yet another aspect, a laminated board for use in furniture elements is provided. The laminated board comprises a board material having a first side and a second side, a first groove provided on said first side of said board material, and a second groove provided on said second side of said board material. The laminated board is characterized in that a laminating foil applied on said first side of the board material and covering said first groove, and said second groove is extending through said board material to connect with said first groove. According to yet another aspect, a furniture element comprising a laminated board according to some embodiments is provided. The furniture element further comprises a supporting structure arranged on said second side of said board material by means of an adhesive, wherein said laminated board is folded along a set of first and second grooves such that the supporting structure is enclosed within said board material.

Brief Description of Drawings

These and other aspects, features and advantages of which the invention is capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which:

Fig. 1 is a side view of a furniture element according to one embodiment;

Fig. 2a is a side view of a laminated board according to another embodiment;

Fig. 2b is a side view of the folded laminated board shown in Fig. 2a;

Fig. 3a is a side view of a laminated board according to a further embodiment; Fig. 3b is a side view of the folded laminated board shown in Fig. 3a;

Fig. 4a is a side view of a laminated board according to another embodiment;

Fig. 4b is a side view of the folded laminated board shown in Fig. 4a;

Fig. 5a is a side view of a partially manufactured furniture element according to one embodiment; Fig. 5b is a side view of the partially manufactured furniture element shown in

Fig. 5a;

Fig. 5c is a side view of the manufactured furniture element shown in Fig. 5a and 5b;

Fig. 6a is a perspective view of a partially manufactured furniture element according to one embodiment;

Fig. 6b is a perspective view of the manufactured furniture element shown in Fig. 6a;

Fig. 7 is a flow chart of a method for manufacturing a laminated board and a furniture element according to one embodiment. Detailed Description of Embodiments

Several embodiments of the present invention will be described in more detail below with reference to the accompanying drawings in order for those skilled in the art to be able to carry out the invention. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The embodiments do not limit the invention, but the invention is only limited by the appended patent claims. Furthermore, the terminology used in the detailed description of the particular embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention.

In an embodiment, according to Fig. 1, a schematic cross section of a furniture element 1 is shown. The furniture element 1 is not to scale. The furniture element 1 consists of a supporting structure 15 being surrounded by a board material 10 and a laminating foil 12. The board material 10 and the laminating foil 12 are covering four sides of the furniture element 1, i.e. the upper side, the lower side, and two edges. The supporting structure 15 comprises a distance material 16 arranged between longitudinal bodies 14. At each corner, folding lines 13 indicate how the laminated board 10 and the laminating foil 12 have been folded. Moreover, a longitudinal slit 24 is present on the upper side of the furniture element.

In an embodiment, the board material 10 may be hardboard, high-density fϊberboard, medium-density fϊberboard, particleboard, cardboard, or any other type of fiberboard.

The laminating foil 12 may be selected from the group comprising paper foil, plastic foil, such as polypropylene foil or polyoleofin foil, veneer, or any other type of foil suitable for laminating. The present inventors have also discovered that it is possible to laminate the board material with veneer, especially if the thickness of the veneer is selected in the interval 0,1 to 1 mm, such as 0,1 to 0,6 mm. Thus, the board product may be provided with an appearance of solid wood, without seams, while being substantially lighter. When the veneer is in the upper part of the interval identified above, the veneer vulnerable at the folding edges. If the edges are sharp, the veneer may be provided with a reinforcing textile fiber mat on the side facing the board material and/or a polyoleofin film on the side of the veneer not facing the board material. In a yet further embodiment, the longitudinal bodies or stiles 14 may be high- density fϊberboard, medium-density fϊberboard, particleboard, cardboard, solid wood or any sandwich construction known per se.

In another embodiment, the distance material 16 may be honeycomb paper, cardboard or any other type of distance material known per se.

The above-described embodiments are advantageous in that cheap and lightweight materials are used, resulting in a cost effective manufacturing process. In Fig. 2a, a side view of an embodiment of an unfolded laminated board comprising a board material 10 and a laminating foil 12 is shown. The laminated foil 12 is arranged on a first side of the board material 10, thus covering a first longitudinal groove 20 provided on the first side of the board material 10. A second longitudinal groove 22 is provided on the second side of the board material 10 and connected to the first groove 20. Thus, the board material 10 is split into two segments 10a, 10b hold together by the laminating foil 12. The first groove 20 provided on the first side of the board is a longitudinal countersink having a chamfer cross section. The depth of the countersink 20 may be between 10 and 90 percent of the thickness of the board material 10. The second groove 22 is provided opposite and connected to the first groove 20, such that the central axis of the first and second grooves 20, 22 coincide. The second groove 22 is a longitudinal countersink having a chamfer cross section. The angle between the two planes in which the groove surfaces of said second groove 22 are located, is selected in correspondence to the desired folding angle of the furniture element. Thus, the angle between the two planes in which the groove surfaces of said second groove 22 are located, may be selected to be 90 °, when the folding angle is desired to be 90 °. The rest of each groove surface of the first groove 20 after the creation of the through slit 25, may then be angled with respect to the groove surface of said second groove 22, respectively. Then each groove surface of the first groove 20 faces the plane of the first side of the board, while the groove surface of said second groove 22 faces the plane of the second side of the board. In one embodiment at least one outer-pointing normal to the tangent plane of each groove surface of the first groove 20 will intersect the plane of the first side of the board, while at least one outer-pointing normal to the tangent plane of each groove surface of said second groove 22 will intersect the plane of the second side of the board. The depth of the second groove 22 is adapted such that a through slit 25 is created between the segments 10a, 10b of the board material 10. With reference to Fig. 2a, the relation between the first groove 20 and the second groove 22 is adapted such that L > 2*B, for example L >~ 2* B, wherein L is the width of the first longitudinal groove 20 at the surface of the first side of the board material 10, and B is the width of the rest of each chamfer side of the first groove 20 after the creation of the through slit 25. Thus, there is no need for unnecessary stretching of the foil 12, when folding the furniture element.

In another embodiment the relation between the first groove 20 and the second groove 22 is adapted such that L > X, for example L >~ X, wherein L is the width of the first longitudinal groove 20 at the surface of the first side of the board material 10, and X is the total width of the rest of the sides of the first groove 20 after the creation of the through slit 25.

In Fig. 2b, a side view of an embodiment of a folded laminated board comprising a board material 10 and a laminating foil 12 is shown. The first groove 20 shown in Fig. 2a provides a beveled edge, reducing the risk of damage of the laminating foil 12 during folding, as described above.

In Fig. 3a, a side view of another embodiment of an unfolded laminated board comprising a board material 10 and a laminating foil 12 is shown. The laminated foil 12 is arranged on a first side of the board material 10, thus covering a longitudinal groove 20 provided on the first side of the board material 10. A second longitudinal groove 22 is provided on the second side of the board material 10 and connected to the first groove 20. Thus, the board material 10 is split by the through slit 25 into two segments 10a, 10b hold together by the laminating foil 12.

The groove 20 provided on the first side of the board is a longitudinal countersink having a chamfer cross section. The second groove 22 is provided opposite and connected to the first groove 20, such that the central axis of the first and second grooves 20, 22 coincide. The second groove 22 is a longitudinal countersink having a chamfer cross section. The depth of the second groove 22 is adapted such that a through slit 25 is created between the segments 10a, 10b of the board material 10. With reference to Fig. 3a, the relation between the first groove 20 and the second groove 22 is adapted such that L >~ 2 *B .

In Fig. 3b, a side view of an embodiment of a folded laminated board comprising a board material 10 and a laminating foil 12 is shown. The first groove 20 shown in Fig. 3a provides a beveled edge, reducing the risk of damage of the laminating foil 12 during folding. In the embodiments disclosed in Fig. 3a and 3b the depth of first groove is greater than 50 percent, such as in the interval of 60 to 90 percent, of the thickness of the board material 10. This allows for increased beveling of the edges of the furniture element, resulting in the allowance of minimal consumption of heavy material in the longitudinal bodies 14, while still providing a maximized beveling of the edges. Large beveling of the edges may for example be asked for due to aesthetic reasons, but also because matching reasons between adjacently located objects, such as other furniture elements with beveled edges.

In Fig. 4a, a cross section view of another embodiment of an unfolded laminated board comprising a board material 10 and a laminating foil 12 is shown. The laminated foil 12 is arranged on a first side of the board material 10, thus covering a longitudinal groove 20 provided on the first side of the board material 10. A second longitudinal groove 22 is provided on the second side of the board material 10 and connected to the first groove 20. Thus, the board material 10 is split into two segments 10a, 10b hold together by the laminating foil 12.

The groove 20 provided on the first side of the board is a longitudinal countersink having a fillet cross section. A radius being in the range between 0.1 mm and three times the thickness of the board material 10 defining the fillet shape. The second groove 22 is provided opposite and connected to the first groove 20, such that the central axis of the first and second grooves 20, 22 coincide. The second groove 22 is a longitudinal countersink having a chamfer cross section. The depth of the second groove 22 is adapted such that a through slit 25 is created between the segments 10a, 10b of the board material 10. With reference to Fig. 4a, the relation between the first groove 20 and the second groove 22 is adapted such that L > 2* AL, for example L >~ 2* AL, wherein AL is the curvature length of the segments 10a and 10b, i.e. the width of the rest of each fillet side of the first groove 20 after the creation of the through slit 25, after the application of the second groove 22.

In Fig. 4b, a side view of an embodiment of a folded laminated board comprising a board material 10 and a laminating foil 12 is shown. The first groove 20 shown in Fig. 4a provides a smooth bead edge, reducing the risk of damage of the laminating foil 12 during folding.

In the embodiments disclosed in Fig. 4a and 4b the depth of first groove is greater than 50 percent, such as in the interval of 60 to 90 percent, of the thickness of the board material 10. This allows for increased beveling of the edges of the furniture element, resulting in the allowance of minimal consumption of heavy material in the longitudinal bodies 14, while still providing a maximized beveling of the edges. Large beveling of the edges may for example be asked for due to aesthetic reasons, but also because matching reasons between adjacently located objects, such as other furniture elements with beveled edges. Fig. 5a, 5b and 5c show an embodiment of a folding sequence of a laminated board for enclosing a supporting structure 15. As shown in Fig. 5a, a laminated board comprising a board material 10 and a laminating foil 12 is provided. A first set of longitudinal grooves 20 are arranged on a first side of the board material 10. Thereafter, the first side of the board material 10 is covered by the laminating foil 12. A second set of longitudinal grooves 22 are arranged on a second side of the board material 10 and aligned with the first set of grooves 20, such that a set of through slots are created. The supporting structure 15 is arranged on the second side of the board material 10, not covering the second set of grooves 22. In this embodiment a supporting structure 15 is applied adjacent and along a second groove 22 on the second side of the board material 10, such that the board material 10 may be folded around the supporting structure 15. In this way a supporting structure 15 may be located in the periphery of the furniture product, improving the flexural rigidity of the furniture product. When the peripheral part of the supporting structure 15, i.e. the part of the supporting structure being located adjacent and along a second groove 22, is a longitudinal body 14, the flexural rigidity is further improved The longitudinal body 14 may then be of a board or wood material.

The laminated board is folded along first grooves 20, 22, as shown in Fig. 5b. As shown in Fig. 5c, the laminated board is folded along second grooves 20, 22 to tightly enclose the supporting structure 15.

A perspective view of an embodiment of an unfolded laminated board for enclosing a supporting structure 15 is shown in Fig. 6a. The board material 10 is provided with a first set of parallel longitudinal grooves 20 extending along the complete board material. Thereafter, the first side of the board material 10 is covered by a laminating foil 12. Further, the board material 10 is provided with a second set of longitudinal grooves 22 comprising four grooves extending along the complete board material on an opposite side of said first set of grooves 20, said second set of longitudinal grooves 22 connecting with said first set of grooves 20, whereby four through slots 61, 62, 63, 64 are created, such that the provisions of the embodiments according to Figs. 1 to 4 are met. The supporting structure 15 is arranged in an area inside the grooves 20, 22. The supporting structure 15 is formed by longitudinal bodies 14, a distance material 16 and a fitting 18 for increasing the robustness and rigidity of the supporting structure 15. Two longitudinal bodies 14 may be located along and adjacent the two inner longitudinal grooves 22, and a third longitudinal body 14 may be located in between, parallel to the first two longitudinal bodies 14. The distances between through slots 61 and 62, and 63 and 64, respectively, are adapted to correspond to the thickness of the supporting structure 15, such that the laminated board product 10 may be folded around the supporting structure 15. Also the distance from through slot 61 to the end 65 of the board product 10 and from through slot 64 to the end 66 of the board product 10 may be equal and adapted such that ends 65 and 66 will be aligned in parallel on the third longitudinal body 14. In one embodiment the third longitudinal body 14 may be located in between, parallel to, and at equal distance from the first two longitudinal bodies 14. Then, two pieces of the same sizes may be obtained by cutting along a folding slit 24, according to below.

In another embodiment, the supporting structure may further comprise different types of distance members, fittings etc.

An embodiment of a folded laminated board, i.e. a furniture element, is shown in Fig. 6b. On the upper side of the furniture element, a folding slit 24, in between ends 65 and 66, is present. The folding slit 24 may be used as a guide for cutting the furniture element into two pieces, through the third longitudinal body 14. The embodiment disclosed in Fig. 6a and 6b allows for the manufacturing of two laminated - with foil 12 - furniture elements, by the vertical cutting along the folding slit 24. Especially, this embodiment allows for the manufacturing of two furniture elements intended to be mounted with the cutting surface, along vertical cut from folding slit 24, directed flush to another surface, such that the cutting surface not will be visually located in the final product in use. For example two shelves may be advantageously manufactured with this method.

Embodiments of a method for providing a laminated board and a corresponding furniture element will now be described. With reference to Fig. 7, a processing line 100 is shown. The method 100 comprises feeding 110 a board material into the processing line. Feeding 110 is followed by arranging 120 a first set of longitudinal grooves on a first side of the board material. The grooves may have a chamfer cross section or a fillet cross section. After this, cleaning 130 of the first side and/or the second side of the board material may be performed. During pre-treatment 140, the first and the second side of the board material is exposed to heat and high pressure by means of a hot steel calendar for smoothening and warming the board material. This can be combined with UV light heating of the board. The smoothening and warming of the board material during pre-treatment 140 facilitates and fastens the subsequent laminating process. Also, the speed of the board material may affect the process. Suitable pre-treatment temperatures for a board material speed of 60 m/min are temperatures selected in the interval of 80 to 200 ⁰ C, for example 80 to 130 ⁰ C, depending on the glue system according to below. The pressure may correspondingly be (on a working width of 1300 mm) selected in the interval of 20 to 120 kN. Thereafter, the method 100 comprises applying 150 a glue system to the first side of the board material. The glue system may for example be a two-component urea glue system. Here, a hardener is dispensed with a roller coating machine directly on the first side of the board. In an embodiment, the amount of hardener used is between 4 and 6 g/m ² , depending on the thickness of a later used laminating foil. The hardener is subject to drying 152. The drying 152 may for example be performed by means of infrared radiation. In the following, applying 154 of a urea glue resin on the hardener may be performed by means of a roller coating machine. In an embodiment, the amount of urea glue resin used is between 30 and 40 g/m ² , depending on the thickness of a later used laminating foil. In other embodiments, the step 150 of applying glue may be utilizing alternative adhesives, such as PVAC, HotMelt, DPI, EPI or other compounds known per se. The glue coated board material is fed into a hot steel calendar for applying 160 a laminating foil on said first side of said board material. Thus, the board material and the laminating foil are bonded together by the glue system. In an optional step 162, the edges of the foil may be trimmed to correct the width before entering the lamination step 16O.After applying 160 the foil, a step 170 of arranging a second set of longitudinal grooves on the second side of the board material is performed. The second set of grooves is extending through the board material opposite to the first set of grooves in order to connect with said first set of grooves. Thereafter, cleaning 180 is performed to remove any dust particles present on the second side of the board material and/or the laminating foil. In an embodiment, the cleaning 180 may be followed by stacking and storing 190 the laminated board. In an embodiment, cleaning 180 may be followed by dispensing 210 an adhesive to the second side of said board material or to the supporting structure. During dispensing 210, the laminated board is passing an adhesive roller machine where PVAC glue is applied on the second side of the board material. Further, HotMelt glue may be applied in areas of the second side of the board material where the supporting structure including longitudinal bodies and/or fittings will later be arranged. In another embodiment, PVAC glue and HotMelt glue are applied to the supporting structure instead of the second side of the board material. After this, arranging 220 a supporting structure at the second side of said board material is performed. This step 220 includes arranging longitudinal stiles and honeycomb paper between the stiles. Folding 230 the laminated board is then performed by folding the outer sections of the laminated board over and towards the central part of the laminated board. The folding 230 is made by means of outer folding rollers which are lifting the outer parts of the laminated board. When the outer parts of the laminated board have reached a vertical position, inner folding discs are supporting the laminated board while the outer portions are folded down to a horizontal and final position. After folding 230, a step of applying heat and high pressure is performed. In this respect the board may be exposed to temperatures selected in the interval of 80 to 200 ⁰ C, for example 80 to 130 ⁰ C, such as 120 ⁰ C, for EVA together with PU; 160 to 200 ⁰ C, such as 180 ⁰ C, for PVAC; and 160 to 200 ⁰ C, such as 180 ⁰ C for UF. The pressure may correspondingly be (on a working width of 1300 mm) selected in the interval of 20 to 120 kN, for example 20 to 40 kN, such as 35 kN for EVA together with PU; 50 to 70 kN, such as 60 kN, for PVAC; and 80 to 120 kN, such as 100 kN, for UF. The laminated board, at this moment in the shape of a sandwich element, is fed into a heated roller press where a number of rollers are pressing and heating the sandwich element in order for the glue to cure, and the sandwich element to at least partially dry. Finally, the sandwich element is discharged during step 240 into a stacking system where manufactured sandwich elements are stored. If the sandwich element is not completely dried or the glue is not completely cured, an optional step of cold pressing 250 is performed.

In another embodiment, the stacking and storing 190 of the laminated board is followed by cutting 192 the laminated board to correct length. The cut laminated board is thereafter exposed to drilling or punching 194 of holes for fittings, which will be provided later. These fittings may then be used as mounting means for different purposes, such as mounting means for using the laminated product as a shelf, table, side piece in furniture, etc. In a subsequent step 196, the fittings are placed and attached in predetermined positions of the holes on the second side of the board material by means of gluing or welding. After this step, the laminated board is further processed by steps 210 to 250 according to what is previously described.

The final furniture element may be cut along the folding line on the upper side of the furniture element in an optional step 260, thus forming two furniture elements each having two sides and one edge covered by the laminating foil. In an embodiment, a double furniture element, i.e. a furniture element not being subject to the cutting 260, may have a width of 200 to 1350 mm, a length of 200 to 6000 mm, and a thickness of 10 to 120 mm.

In another embodiment, a single furniture element, i.e. a furniture element being subject to the cutting 260, may have a corresponding width of 100 to 1350 mm, a length of 200 to 6000 mm, and a thickness of 10 to 120 mm.

It will be appreciated that the embodiments described in the foregoing may be combined without departing from the scope as defined by the appended patent claims.

Although the present invention has been described above with reference to specific embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the invention is limited only by the accompanying claims and, other embodiments than the specific above are equally possible within the scope of these appended claims.

In the claims, the term "comprises/comprising" does not exclude the presence of other elements or steps. Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented by e.g. a single unit or processor. Additionally, although individual features may be included in different claims, these may possibly advantageously be combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. In addition, singular references do not exclude a plurality. The terms "a", "an", "first", "second" etc do not preclude a plurality. Reference signs in the claims are provided merely as a clarifying example and shall not be construed as limiting the scope of the claims in any way.