IES61972B2 - Laminated board - Google Patents

Description

LAMINATED BOARD This invention relates to a laminated board. In particular, it relates to a grid laminated board which can be used for example in building and construction and in making furniture.

Timber based board materials for the furniture, interior, building and construction trades have been developed during the twentieth century as adhesive technology has improved to an extent that lamination of timber elements can provide an effective board material. The main types that have been developed are firstly plywood, where veneers, either sawn, sliced or rotary cut are glued together, the grain of each veneer being generally at right angles to its neighbour; secondly battenboard, blockboard and laminboard, where there is a core of timber strips that have veneers on the outside faces, and thirdly particle board, where the timber has been reduced to its fibrous state and pressed and glued into a uniform board, as found in chipboard, M.D.F. (Medium Density Fibreboard) and O.S.B. (Orientated Strand Board).

In all of the known types of timber based board materials, the components completely touch one another λ χ : .'χ Γη Γι ) Ο ί / : ,ί - 2 or are adjacent to one another. Because of this, conventional boards having a thickness sufficient for larger pieces of furniture and the like are heavy in weight and are also costly to manufacture. Furthermore, the conventional boards are not readily modified for a particular function.

It is therefore an object of the invention to provide a laminated board for use in building and construction and in the making of furniture, which has improved structural strength and which may be readily modified depending on the desired function.

According to the invention there is provided a laminated board especially for use in building and construction and in making furniture, the board comprising a plurality of layers, each layer comprising a plurality of solid timber strips in substantially parallel spaced apart relationship and having opposing faces, the strips being bonded at their faces to the strips in an adjacent layer, the strips in each layer being orientated at an angle relative to the strips in the adjacent layer so as to form a lattice structure having a plurality of interstices, and a means for supporting the layers on at least one face of the board.

Preferably the supporting means comprises at least one sheet having opposing faces bonded to each of the outermost layers of the strips at their faces. More preferably, a second sheet is bonded to the sheet that is bonded to the strips.

Preferably, at least one further sheet is interposed between and bonded to the faces of the strips of inner adjacent layers.

Preferably, the strips in adjacent layers are orientated at an angle of 90° relative to one another.

The strips are preferably uniform in depth and width and are preferably spaced at an equal distance apart of approximately 10 mm relative to one another.

The strips preferably have a depth of approximately 5 mm and a width of approximately 10 mm, although the depth may vary between approximately 4 and 8 mm and the width between approximately 6 and 12 mm while still retaining the structural properties of the board.

The sheets are preferably formed from strips bonded together, the strips preferably comprising timber. The strips preferably have a depth of approximately 2 mm and a width of approximately 50 mm, although considerable variation of these dimensions is possible.

The board of the invention will generally be provided in thicknesses in excess of 50 mm and will have a minimum thickness of approximately 20 mm, preferably 30 mm.

The board of the invention may be in the form of an interior panel having an electrical conduit therein. It may also be in the form of a building board comprising insulating means. The building board may also comprise a perforated metallic sheet connected to low voltage electricity so as to provide an active heating system in a wall of a building.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a detailed perspective view of a corner of a laminated board according to the invention; Fig. 2 is a perspective view of a board according to the invention for use in making furniture; Fig. 3 is a perspective view of a board according to the invention for use as an interior panel; and Fig. 4 is a perspective view of a board according to the invention for use as a building board.

Referring now to the drawings in which like numerals represent like parts, there is shown a laminated board according to the invention. The board 10 comprises a plurality of layers 11, each layer 11 comprising a plurality of solid timber strips 12 in substantially parallel spaced apart relationship and having opposing faces 13 (see Fig. 2). The strips 12 in adjacent layers are bonded together at their faces 13 by adhesive or other suitable means. The strips 12 in adjacent layers are orientated at an angle, preferably 90°, relative to one another so as to form a lattice structure having interstices 14.

The solid timber strips 12 are preferably uniform in depth and width, the depth being preferably approximately 5 mm and the width being preferably approximately 10 mm. It will, however, be appreciated that some variation of the depth and width of the strips is possible while still retaining the desired structural properties of the board 10. The strips 12 in each layer 11 are equally spaced apart, preferably at a distance of approximately 10 mm. However, the spacing may also be varied, depending on the function of the board.

The strips 12 in adjacent layers 11 are preferably orientated so that the grain of the timber is in an opposite direction in each adjacent layer 11.

In the embodiments illustrated, each of the outermost layers 11 is bonded to an inner sheet 20 at the faces 13 of the strips 12. The sheet 20 is in turn bonded to a second or outer sheet 21 at the faces of the sheets 20,21. Bonding is effected by adhesive or other suitable means. A single sheet 30 is interposed between and bonded to the faces 13 of the strips 12 of adjacent layers 11, the layers 11 being disposed at substantially the centre of the board 10. The sheets 20,21 and 30 are preferably formed from strips of timber bonded together by adhesive or other suitable means. The strips (not shown) can have any suitable dimensions but conveniently have a depth of approximately 2 mm and a width of approximately 50 mm.

The board 10 according to the invention will preferably be provided in thicknesses of at least 30 mm and generally in excess of 50 mm, usually in 10 mm thickness increments. One of the advantages of the board 10 is that it is light in weight for its thickness, in contrast to conventional boards.

Fig. 2 shows a modification of the board 10 according to the invention for use in making furniture, one corner of which has been partially cut away showing the layers and the sheets 20,21 and 30. In this embodiment, the board 10 has solid wood lipping 40 bonded to two sides a and b thereof. Because of the thickness of the board , it can be readily bored or cut into to provide recesses therein of any configuration, to receive conventional timber inserts, such as dowels 41, without diminishing the structural integrity of the board. The board 10 may be bored or cut into in a direction which is either substantially parallel or substantially perpendicular relative to the plane of the board 10.

Fig. 3 shows another modification of the board 10 for use as an interior panel. In this embodiment, adjacent 15 sides c and d of the board 10 have been drilled to provide passages for conventional electrical conduits 50 of plastics material, one of which is partially inserted in side d. An electrical socket 51 is provided which is in electrical contact with the conduits 50. Because of its thickness, the board 10 can accommodate the electrical conduits 50 without losing any of its structural properties.

It will of course be appreciated that the board 10 according to the invention may be constructed in a variety of configurations so that, for example, curved or twisted panels may be produced.

Fig. 4 shows a further modification of the board 10 for use as a building board. Because of its lattice structure, the board 10 can be readily ventilated. The lattice structure also facilitates insulation of the board 10. This can be achieved in a number of ways. For example, a plastics foam material 60 may be injected into the interstices 14, or strips 61 of suitable material such as cork, polyurethane or polystyrene, may be inserted into the interstices 14 so that they extend across the entire board 10. Alternatively, a thin sheet of plastics material, such as bubblewrap 62, may be inserted between any two adjacent layers 11 of the strips 12 before bonding takes place. The sheet 62 is perforated at locations which are in register with bonding positions of the strips 12, so that the adhesion of the strips 12 remains effective.

A thin film or sheet 63 of metal or plastics material may also be incorporated in the board 10 to provide a barrier to moisture, for example. The film or sheet 63 is perforated and inserted in a manner similar to that described for the sheet 62.

In a further modification, a thin metal sheet or film 64 can be incorporated in the board 10. The metal sheet 64 is perforated and inserted in a manner similar to that described for the sheet 62. The sheet 64 can be connected to low voltage electricity to provide a heating element in the building board 10. The sheet 64 may also be in the form of a mesh, thereby obviating the necessity for perforation.

It will be understood that the sheets 62,63,64 extend across the board 10, only a portion of these sheets being shown in Fig. 4.

The board 10 of the invention may be treated with wood preservative agents and fire resistant chemicals and because of its lattice structure a high degree of penetration by these agents is possible.

* The manufacturing process for making a laminated board according to the invention comprises using timber that is extracted from the forest, converted to a baulk size of approximately 65mm2, and seasoned to a moisture content at or below 10%. These baulks are then inspected to determine where there are structural faults such as knots, short grain, etc. The baulks are cut at these places, and rejoined using a comb joint cutter to give structurally strong lengths. These lengths are then reduced by sawing and planing to the precise sizes needed to manufacture the board. The first process is to make lattices from the small strips.

A press is used that has two jigs, one for the top and one for the bottom platen. The top jig holds the strips in one direction which are automatically fed to that jig and held in place by a vacuum. The bottom jig 20 holds the strips in the second direction and before being fed into this lower jig they are coated with adhesive on the top side. The press is then closed and a lattice is made when the adhesive has cured. the resulting lattice is then easily handleable.

The next process is to make the timber sheets. The strips, approximately 2mm thick and 30 - 50mm wide, are joined by their edges to make the size required. Now lattices and sheets can be fed into another press to ’ 30 make the board to the required thickness for the application envisaged, e.g. furniture or a building ’ board.

The invention seeks to use solid timber in its structural state, rather than reducing timber to thin peeled veneer, or to chips or fibres as found in plywood, particle board or fibre board. The invention seeks to be able to utilise timber that is of second grade or less, since the strips used are made from baulks of timber that are end comb-jointed when major defects that are present are removed by cutting away. The invention is always concerned with using solid timber that is sawn and planed to provide the strips for lattices and for the sheets that make up the board. The invention is made by laminating the above components into a board material.

The invention thus provides a laminated board having a lattice structure, which structure enhances the strength of the board and allows it to be readily adapted to a variety of functions. It is possible to produce at a low cost larger items of furniture, such as table tops, in one piece, which are structurally sound and relatively light in weight. The inventive board can also be used to provide interior panels and building boards, as the thickness of the board can readily be increased as required. Furthermore, as an entirely novel feature of the invention, the building board may comprise a heating element which has obvious advantages for keeping a building warm.

The invention is not limited to the embodiments described herein which may be modified or varied without departing from the scope of the invention.

Claims (5)

1 . A laminated board comprising a plurality of layers, each layer comprising a plurality of solid timber 5 strips in substantially parallel spaced apart relationship and having opposing faces, the strips being bonded at their faces to the strips in an adjacent layer, the strips in each layer being orientated at an angle relative to the strips in the 10 adjacent layer so as to form a lattice structure having a plurality of interstices, and a means for supporting the layers on at least one face of the board. 15 2. A laminated board according to claim 1, wherein the supporting means comprises at least one sheet having opposing faces bonded to each of the outermost layers of the strips at the faces thereof, the supporting means preferably comprising two sheets 20 bonded together and wherein a further sheet is interposed between two inner adjacent layers and bonded thereto. 3. A laminated board according to claim 1 or 2, wherein 25 the strips in adjacent layers are orientated at an angle of approximately 90° relative to one another and are uniform in depth and width.

2. 4. A laminated board according to claim 3, wherein the strips have a depth of from approximately 4mm to 8mm, preferably approximately 5mm, and a width of from approximately 6mm to 12mm, preferably

3. 5 approximately 1Omm and are spaced at an equal distance apart of approximately 10mm relative to one another, and each sheet being formed from solid timber strips bonded together, each of these strips preferably having a depth of approximately 2mm and a

4. 10 width of approximately 50mm. 5. Use of a laminated board according to any preceding claim as an interior panel or a building board or in

5. 15 making furniture.