WO2022126169A1

WO2022126169A1 - Board pair, wood composite panel and method for the production thereof

Info

Publication number: WO2022126169A1
Application number: PCT/AT2021/060478
Authority: WO
Inventors: Hans-Peter Leitinger
Original assignee: Leitinger Hans Peter
Priority date: 2020-12-14
Filing date: 2021-12-14
Publication date: 2022-06-23
Also published as: EP4259397A1; AT524491A1

Abstract

The invention relates to a board pair (14) composed of two boards (2) connected together along their longitudinal narrow sides (5) profiled in the longitudinal direction (4), wherein the profiling is preferably a profiling that has already been carried out in the lumber mill when the boards (2) are in the fresh state, the boards (2) originating from the same tree trunk, preferably from the same tree trunk cut into standard raw wood lengths and being cut from corresponding layers of the tree trunk which are opposite one another with respect to a longitudinal axis of the tree trunk.

Description

Pair of boards, composite wood panel and method of making same

The invention relates to a pair of boards consisting of two boards connected to one another along their narrow longitudinal sides which are profiled in the longitudinal direction, with the features of the preamble of claim 1.

The invention further relates to a composite wood panel made of at least one layer of pairs of boards connected to one another on their profiled longitudinal narrow sides.

Finally, the invention also relates to methods for producing the pairs of boards and composite wood panels mentioned.

Single-layer or multi-layer composite wood panels made of cross laminated timber or sawn timber are known from the prior art. Multi-layer composite panels made of cross-laminated timber, also sold under the English name "Cross Laminated Timber", are currently made exclusively from softwood and are preferably made up of three layers, usually bonded crosswise to one another. Individual layers can also be replaced by other wood-based materials such as OSB panels or laminated wood.

Single-layer or multi-layer wood composite panels offer the advantage that they can be produced as a large-format "carpet" from which components with any surface dimensions can be sawn or divided afterwards. In this process, the individual boards are arranged lengthwise and glued together in a press along their longitudinal narrow sides. To do this, the press must apply “area pressure” to the visible surfaces of the interconnected boards and usually also “side pressure” to the narrow sides of the outermost boards in the composite board. As a result, the format of the carpet that can be produced is limited to the size of the press, in particular its maximum pressing width.

From an economic point of view, it is fundamentally desirable to use so-called side boards for individual or all layers of the composite wood panel. So that the side boards can be connected to each other more easily, they are first formatted to a rectangular cross-section, which results in waste. If you leave the side boards with and without their wane and the trapezoidal cross-section, they form oblique boundary surfaces along adjacent longitudinal narrow sides. The pressing of such side boards is particularly challenging and lateral pressure must be applied in any case, whereby particular care must be taken to coordinate surface pressure and lateral pressure so that there is no cupping, warping or the like at the boundary surfaces during or after the pressing process. EP 3 079 870 B1 describes such a method, in which the dried side boards are first divided longitudinally along their board center in order to reduce cupping. The extra split creates twice as many pieces (boards) to be manipulated and further processed, adding cost from sawing, loss of joint due to splitting down the middle, the extra glue, and increased processing time. For the above reasons, such wood composite panels can only be used in high-quality products, for example for furniture and interior design.

It is the object of the present invention to provide pairs of boards and single- or multi-layer composite wood panels and methods for their production which overcome the above-described problems of the prior art, or at least reduce them.

This object is achieved by providing pairs of boards with the features of claim 1 and composite wood panels with the features of claim 10, by a method for producing a pair of boards according to claim 13 and by a method for producing composite wood panels with the features of claim 18. Advantageous configurations of the invention are set out in the dependent claims, the following description and the drawings.

A pair of boards according to the invention consisting of two boards connected to one another along their narrow longitudinal sides profiled in the longitudinal direction, the profiling preferably being a profiling already carried out in the sawmill when the boards are fresh, is characterized in that the boards are made from the same tree trunk, preferably from the same standard raw wood length cut tree trunk, with substantially the same moisture content and conicity and are cut from mutually corresponding layers of the tree trunk lying opposite one another with respect to a longitudinal axis of the tree trunk, with a guiding chamfer being formed on the boards to be connected, the two boards being in the fresh state of the planks have been joined and the two planks are in neutral annual ring position with respect to each other. Such a pair of boards is shown, for example, in FIG. 6 and is described in more detail below. It can be seen from the boards of the pair of boards, even when joined together after manufacture, that the boards were profiled in the fresh state and come from opposite sides of the same log. The profiling when fresh can be seen from the shrinkage behavior. The fact that the boards come from the same tree opposite each other is recognizable by their very similar density, a similar growth ring pattern with essentially the same pattern of growth ring widths, the same moisture content, the same quality and spacing of knot formation in annual growth, the same shrinkage behavior. These properties can be found, for example, on the end face (also referred to as the "plaited face" in technical jargon because it is on the side of the trunk facing the treetop) and the stick face (the stick face is opposite the end face, i.e. it faces the rootstock of the tree trunk) of the Boards are inspected or measured comparatively.

The two boards of the pair of boards have been connected to one another when the boards are fresh. Since the boards are already connected in the sawmill while they are fresh and come from the same trunk and from the same, opposite layer in the tree trunk, they have grown as a natural product of essentially the same quality, conicity and, in particular, about the same moisture content. The same or at least very similar moisture content of the two boards is a prerequisite for functioning bonding when moist, e.g. with PU adhesive, whereby the bonding with PU adhesive is supported in the throughput by using microwave ovens and/or other measures for superficial heating can.

Furthermore, the planks can be two narrow side planks, whereby by connecting these narrow side planks you immediately get a wider pair of planks in the fresh state in the sawmill. This offers the advantage that it is no longer the individual boards that have to be manipulated for further processing, but rather the pair of boards, as a result of which the number of items to be manipulated is reduced by half. As a result, a processing system can handle twice the output without changing the cycle speed of the system. This is particularly advantageous because ever higher quantities are required in industrial sawmills. Furthermore, the processing of the wider, stable pairs of boards also causes fewer disruptions to the operation of the system, because the pairs of boards are parallel and straight on the outside, in contrast to individual boards that are often bent. This reduces operating costs considerably. In addition, it is possible, for example, instead of two narrow boards, each 10 cm, to process approx. 50% wider boards of approx. 15 cm and thus to obtain a pair of boards with a width of 30 cm in identical quality across its width and thus approx. 40 - Achieve 50% increase in yield. The pair of boards is preferably provided on its two narrow longitudinal sides with guide chamfers that are parallel to one another.

In the pair of boards according to the invention, the two boards are arranged in a neutral annual ring position with respect to one another. By connecting the "twin" boards while they are still fresh in the sawmill, it is ensured that the correct boards (from the same opposite layer of the same tree trunk) are assigned to each other. You also save yourself the subsequent manual (by visual inspection) or automatic (cameras, etc.) assignment and thus exclude a source of error from the outset. In this way, the matching boards can be arranged in a neutral annual ring position, which means that the craft rule for solid wood, i.e. arranging the boards to be connected in a neutral annual ring position, is observed, which leads to neutral shrinkage and swelling of the joined boards without tension and/or warping. With the invention, this can now be put into practice industrially at hitherto unattainable low costs. Arranging in neutral growth ring position means that adjacent boards are arranged so that the growth ring portions of the boards are juxtaposed in opposite curvature. This is visible on the pair of boards on the front and floor side. Due to the arrangement of the two boards in a neutral annual ring position and profiling and connection when fresh, incorrect bonding of the board pairs with the sloping tree edge is also ruled out. The boards show conformal shrinkage and swelling ("negative shrinkage"), so that over the lifetime of the board pairs, there are not such large stresses in the glued joints. The known higher quality of side boards, these are boards that were cut from the side of the tree, e.g. in terms of their higher modulus of elasticity, and the use of the side boards for the pair of boards made possible by the invention makes it possible to use pairs of boards with conforming strength from the previously considered rather inferior (because they are thin and narrow in volume and have an inevitable wane) to reputable sideboards.

In a particularly preferred embodiment of the pair of boards according to the invention, the profiles of the boards on the common longitudinal connection are designed as dovetail profiles that complement one another, the longitudinal connection optionally being provided with an adhesive, and with the formation of several dovetail profiles on each board, adjacent dovetail connections are preferably designed the other way around . For example, in the formation of several dovetail profiles on each board adjacent Dovetail joints for each approx. 10 mm board thickness (multiple thickness) should be designed in reverse to each other. The dovetail profiles are preferably milled in the curve of the tree edge. These measures and, if necessary, further optimization result in the joining of the two profiled boards by sliding them into one another with continuous guidance on the guide chamfer that can be used continuously according to the invention, formed by profiling in the rounding of the wane edge, already creates a very good mechanical connection through positive locking, which enables the use of adhesive Reduce, for example only apply one line of glue in the middle or one line of glue on each of the outer sides. Furthermore, depending on the quality and requirements in the further processing of the pairs of boards into multi-layer composite panels with visible surfaces on the outside and middle layers on the inside, sorting can already be carried out during the profiling of the boards in relation to more or less wane or portioning of adhesive (full or through each or only every second trace of glue) in order to create a fully glued connection without a wane, i.e. the tree bark edge, to form the pair of boards for the visible surfaces, or e.g. for certain low qualities, such as middle layers, to use less glue with a small wane of the boards, or to connect the Produce boards only by sliding the dovetail profiles of the boards into each other. Such qualities can be used as middle layers for the composite panels, especially for cross laminated timber. By milling the dovetail profiles in the curve of the tree edge, you mainly use their figure from the previously milled edge/long side of the board practically outside the sloping connecting line of the corner points and minimize the loss of wood when creating the mechanical connection of the two joining partners, whereby the yield can be increased.

The width of each board in the pair of boards is expediently at least 30, preferably at least 40 mm at its narrow end, with the board width preferably being able to be selected as large as possible, e.g. in 1 mm increments. The 30 mm minimum width is measured from the point where the board is at least brushed by the saw.

Conventionally, the board width is at least 80 mm and is increments of at least 20 mm. In addition, boards with tree edges could hardly be used in the prior art. This meant that only thin side boards could be produced, which is why, for better utilization of the tree trunk, especially with larger diameters, two side boards were usually cut from each side of the tree trunk, i.e. a total of four boards, which, during further processing into pairs of boards, were cut through the many thin Boards (double the number) cause twice the amount of work. The invention makes it possible to also increase the thickness of conical side boards with the sloping tree edge to process. This in turn means that the individual side boards can be produced much thicker than conventionally, in particular at least twice as thick as conventionally, and thus of higher quality, and in addition the conventional sawing joint is avoided and thus an increase in yield is achieved, and that the thicker boards are already through form fit by means of dovetail joints, preferably while still fresh, thicker pairs of boards can also be produced without twisting and shrinkage.

In a further preferred embodiment of the pair of boards according to the invention, the boards are profiled in relation to one another without overthrust and the guide chamfers are designed as stops for the formation of further dovetail profiles for connecting pairs of boards by means of the dovetail profiles at the longitudinal connections. The advantage of this embodiment lies in the possible production of wooden panels of any width from these pairs of boards without a press. These wood panels, preferably in specified system widths, can be extended by finger jointing as more stable construction wood connected by at least one adhesive joint and can be used for longitudinal, middle and transverse layers or for visible or top layers for wood composites.

In an alternative embodiment of the pair of boards according to the invention, each board has a guide bevel incorporated in the fresh state and the pair of boards has been profiled in the dry state on its longitudinal narrow sides with complementary folding profiles, preferably with a 0.3 to 0.6 mm overthrust. In the case of a wood composite panel produced from such pairs of boards connected to one another on their longitudinal narrow sides, it is characterized in that adjacent pairs of boards are arranged in a neutral annual ring position. To produce this composite wood panel, the pairs of boards are laid in a layer width in a neutral annual ring position according to the rules of the trade and pushed through the press in the cycle of the width of a press, preferably a high-frequency press, with a short pressing time. From this kind of "endless" composite wood panel, composite wood panels can be cut to any width as required, e.g. in system widths of 250, 500, 750, 1000, 1250, 2500 mm, and then processed further.

In wood composite panels according to the invention made of at least two superimposed layers of pairs of boards, the pairs of boards in each layer are provided with adhesive on their profiles and adhesive is applied to the surfaces of adjacent layers of pairs of boards, the pairs of boards in each layer being arranged parallel to one another. As a result, the layers of the composite wood panel can be pressed together in the same work step simply by applying surface pressure to the outside layers and connected to each other, whereby a board width in the cycle width of the press, ie in the feed length of the press, can be produced. The wood composite panel produced in this way is already bound and practically produced in a continuous process, whereby by placing the pairs of boards in the same layers parallel to one another and applying adhesive to the feed table, another cycle width is already available ready for further pressing in the push-through, in order to produce endless panels, as shown in Fig 4 shown to manufacture. The desired width of the wood composite panel can be cut from these panels as required from the endless wood composite panel.

An expedient embodiment of the wood composite panel according to the invention has at least three superimposed layers of board pairs according to the invention, the board pairs of a respective layer being provided with adhesive on their profiles and adhesive being applied to the surfaces of adjacent layers of board pairs, the board pairs of adjacent layers being arranged crosswise to one another .

The invention also relates to a method for producing a pair of boards, which is characterized by cutting two boards from the same log, preferably from the same log cut to standard raw wood length, in the fresh state of the log from corresponding ones, with respect to a longitudinal axis of the log opposite layers of the tree trunk, forming profiles on at least one of the longitudinal narrow sides of the boards when the boards are fresh, arranging the two boards so that the boards are mirrored to one another in relation to a central transverse axis, and connecting the boards the longitudinal narrow sides by sliding them into each other along their profiles, preferably when the boards are fresh, optionally with prior application of adhesive to the profiles.

The pair of boards is preferably provided with guide chamfers parallel to one another on its two longitudinal narrow sides and the two boards are arranged in a neutral annual ring position in relation to one another.

An exact and rapid production of the pairs of boards on an industrial scale is achieved by forming the profiling of the boards at the common longitudinal connection as complementary dovetail profiles, wherein preferably when forming several dovetail profiles on each board, adjacent dovetail connections are formed in reverse to each other, in contrast to the prior art the technique in which the dovetail joints are equal to each other be formed. The advantage of the inverted formation of dovetail profiles according to the invention is that breaking off of the heads or chipping off of dovetail parts in the groove at the dovetail corner can be avoided, which occurs more easily in the prior art, particularly on one side of the beveled edge. To achieve the goal defined above, it is also preferred that the boards are profiled without overfeeding in relation to one another, the guide chamfers with abutment for the formation of the dovetail profiles and further for controlled guiding on the guide chamfer used throughout the stop for telescoping without any misalignment and deviations be used.

In a preferred embodiment of the method according to the invention for producing a pair of boards, each board is provided with a guide bevel in the fresh state and the pairs of boards are profiled in the dry state on their longitudinal narrow sides 5 with complementary folding profiles, preferably with an overthrust of 0.3 to 0.6 mm the folding profiles.

A preferred embodiment of the pair of boards according to the invention is characterized in that the geometry of the dovetails in the tangential wood of the annual rings in the round tree edge at the root of the tails, preferably with a minimum width of 6 mm, is designed with higher strength for greater loads from transverse forces, the central dovetails are about twice as high as the laterally outer dovetails in the curve of the tree edge. For example, the extended flank central dovetails have addendums of about 4.5 mm, 6 mm, or 8 mm, and the laterally outer dovetails have addendums of about 2 mm, 2.5 mm, 3 mm, or 4 mm. This reduces the risk of breakage from the wedge effect on the tangential growth rings, especially in the softer springwood ring. If the dovetails in the standing wood of the radial annual rings in the trapezoidal center plank, e.g. the trapezoidal boards Z with Z', see Fig. 15, are about 3 mm wide and about 2 mm high at the root, the boards can be formed by dovetails in preferably a grid of e.g. 10 mm as a multiple thickness to form at least one pair of boards from the wedge-shaped central plank Z with Z' again in parallel form.

The invention also relates to a method for producing composite wood panels from pairs of boards produced according to the method for producing pairs of boards described above. This wood composite panel manufacturing process includes: flattening the pairs of boards, forming complementary inclined profiles with folding profiles in opposite shapes on the narrow longitudinal sides of the pairs of boards facing each other, arranging the pairs of boards next to each other, applying adhesive to the narrow longitudinal sides of the pairs of boards, joining adjacent pairs of boards on their narrow longitudinal sides sides, optionally with simultaneous hooking of the folding profiles, and pressing of the joined pairs of boards.

The method according to the invention for the production of composite wood panels provides for the production of multi-layer composite wood panels, which are constructed in at least two layers, that the pairs of boards are arranged in at least two superimposed layers and connected to one another, the pairs of boards of each layer being arranged parallel to one another and the adjacent layers glued together over a large area in the same work step. These wood composite panels can be produced with very little added adhesive and are therefore ecologically compatible. By arranging neighboring boards of the board pairs in a neutral annual ring position, shrinkage/swelling, especially at the glue joints, is reduced even later, when installed, and at the sloping connections on the long side walls (which are formed from the tree edges). Due to the neutral position of the annual rings, there is little or no stress at all. This also applies to the surface bonding of adjacent layers on pairs of boards, for which homogeneous side boards with their relatively flat annual rings are ideally suited.

According to the invention, several multi-layer composite wood panels in the panel width or in predefined required widths or system widths are to be connected to one another by means of a finger joint, with the composite wood panels being layered in at least two layers, with the boards first being sorted in raw wood length without knots or parts of the boards containing knots being cut off to produce the pairs of boards are, and the multi-layer wood composite panels are cut into glued squared timber. The finger-joint connection can be subjected to a standardized tensile test, so that the squared timber can be used as long, stable beams/beams with quality assurance.

Further details, features and advantages of the invention result from the following explanations of exemplary embodiments shown schematically in the drawings. In the drawings show: - Fig. 1 in a cross-sectional view a detail of a single-layer composite wood panel according to the invention according to a first embodiment;

- Figure 2 is a cross-sectional view of a detail of a single-layer composite wood panel according to the invention according to a second embodiment;

3A to 3D show a pair of boards according to the invention in a first embodiment in a cross-sectional view (FIG. 3A), a view from above (FIG. 3B), a side view from the left (FIG. 3C), and a perspective view from top right (Fig. 3D);

- FIG. 4 each in a cross-sectional view a section of a single-layer, two-layer and three-layer composite wood panel according to the invention based on the second exemplary embodiment;

5A and 5B show a board for a pair of boards according to the invention, without (Fig. 5A) and with (Fig. 5B) a folding profile, in a mixed perspective view, the profile for connecting the boards being shown inserted;

6 shows the production of a pair of boards according to the second embodiment.

- Fig. 7 and Fig. 8 a further embodiment according to the invention of a single-layer composite wood panel in cross section;

9A is a cross-section of a three-ply plywood-wood composite panel made from the single-ply wood-composite panels of FIGS. 7 and 8;

FIG. 9B shows a variant of the three-layer plywood-wood composite panel of FIG. 9A in cross-section;

- Figure 10 shows a cross-section of a side board cut from a fresh tree trunk;

- Fig. 11 another side board cut from a fresh tree trunk in cross-section;

- Fig. 12 another side board cut from a fresh tree trunk and then divided in cross section;

FIG. 13 shows a pair of boards made up of boards connected to one another by a plurality of dovetail profiles;

FIG. 14 shows the sectional view of boards cut from a medium-thickness log; FIG.

Figure 15 is a sectional view of the division of a log in accordance with aspects of the present invention showing the parallel pairs of sapwood boards and pairs of boards from the wedge shaped center plank;

16A to 16F show the production of pairs of boards and wood composite panels made from thin tree trunks, so-called weak wood;

17A to 17F show the alternative production of pairs of boards and wood composite panels made from thin tree trunks, so-called weak wood; and

18A to 18E show the manufacture of a pair of boards according to FIG. 13. FIG. 1 shows, in a cross-sectional view, a section of a single-layer composite wood panel 1 according to a first exemplary embodiment. The wood composite panel 1 is made from a plurality of boards 2 laid against one another, which may be side boards made from a block-shaped substrate 3 (see FIG. 6), for example raw round wood. The boards 2 come from the same tree trunk, preferably from the same tree trunk cut to standard raw wood length, and are cut from corresponding layers of the tree trunk lying opposite one another with respect to a longitudinal axis of the tree trunk. The boards 2 have a trapezoidal cross-section, with longitudinal narrow sides 5 forming the legs of the trapezoidal cross-section, and with adjacent boards 2 being arranged mirrored to one another in relation to a central transverse axis 6 . The boards 2 are connected to one another with essentially the same wood fiber direction along their longitudinal narrow sides 5 which are profiled in the longitudinal direction 4 . The outer visible surfaces of the boards 2 connected to one another form an upper side 7 and an underside 8 of the wood composite panel 1 . The boards 2 have a board thickness of 11. According to FIG. 1, the longitudinal direction 4 is normal to the plane of the page. Two boards 2 are connected to form a pair of boards 14 (see FIG. 3). By placing the pairs of boards 14 next to one another, a surface of boards 2 that is essentially infinitely long in the transverse direction, a so-called “carpet”, can be provided only by applying surface pressure, ie without additional lateral pressure.

The boards are profiled along their longitudinal direction 4 on the longitudinal narrow sides 5, the profiling preferably being a profiling that has already taken place in the sawmill when the boards 2 are fresh. The profile of the longitudinal narrow sides 5 has a folding profile 9 with a folding profile angle SW of less than or equal to 90 angular degrees, in the present example according to FIG. 1 approximately 60 angular degrees. In addition, the folding profiles 9, as shown in FIG. 1, can be offset from the central transverse axis 6. The distance from the central transverse axis 6 can be approximately 0.1 mm to 0.8 mm, preferably approximately 0.3 mm to 0.6 mm, particularly preferably approximately 0.4 mm to 0.5 mm. As a result, after the boards 2 have been placed next to one another and before the boards 2 have been pressed into pairs of boards 14 or to form a composite wood panel 1, an overthrust 12 is created between adjacent boards 2. This overthrust 12 can—according to the aforementioned examples for the distance from the central transverse axis 6—in about 0.1 mm to 0.8 mm, preferably about 0.3 mm to 0.6 mm, particularly preferably about 0.4 mm to 0.5 mm. 2. The profile of the longitudinal narrow sides 5 can have more than one folding profile 9, preferably two folding profiles 9, with the folding profile angle SW of all folding profiles 9 being less than or equal to 90 angle degrees. The folding profile angles SW of the folding profile 9 or of all folding profiles 9 are, for example, 80 angular degrees or less, preferably 70 angular degrees or less.

FIG. 2 shows, in a cross-sectional view, a section of a single-layer composite wood panel 10 according to the invention in accordance with a second exemplary embodiment. The wood composite panel 10 according to the second embodiment is essentially the same as the wood composite panel 1 according to the first embodiment, with the difference that two adjacent boards 2 are connected along their contacting longitudinal narrow sides 5 via a dovetail profile 13 to form a pair of boards 14 (see Fig. 3 ) are connected to each other. Alternatively, the boards 2 to be assembled into pairs of boards 14 can be equipped with two or more than two, for example three, four or five, dovetail profiles 13 . After connecting the adjacent boards 2 to form a pair of boards 14 (see Figures 3 to 6), each pair of boards 14 along its outer longitudinal narrow sides 5 each have a profile with a guide chamfer 17 (see Fig. 5A) or a folding profile 9 with a Folding profile angle SW of less than or equal to 90 degrees, in the present example according to Figure 2 in about 60 degrees. With folding profile angles SW below 80 degrees, an additional hooking effect is created.

In this exemplary embodiment, too, the pair of boards 14 is made from two boards 2 connected to one another along their longitudinal narrow sides 5 profiled in the longitudinal direction 4, with the boards 2 originating from the same tree trunk and being cut from corresponding layers of the tree trunk that are opposite one another in relation to a longitudinal axis of the tree trunk are. The profiling is preferably produced in the sawmill when the boards 2 are fresh. For example, the boards 2 are side boards of a pair of boards 14 from the same trunk layer of raw round wood (see FIG. 6) and are connected to one another via a dovetail profile 13 . These two boards 2 then have an annual ring position that is favorable to one another and an essentially identical quality with regard to fiber and moisture. After the boards have been connected, the pair of boards 14 has an essentially rectangular and stable shape, for example according to FIGS. 3A to 3D, without the risk of bending. By profiling and placing such pairs of boards 14 parallel to one another, for example according to FIGS. If, during (compression) pressing of the boards 2 to form the wood composite panel 1 or 10, a surface pressure FD (see Figure 4, FD represented by the large number of parallel arrows) is applied to the top 7 and/or the bottom 8 of the wood composite panel 1 or 10 the folding profiles 9 prevent the boards 2 from being pushed apart transversely to the direction of the contact pressure, ie essentially transversely to the present effective direction of the surface pressure FD. Any overhangs 12 that may be present before pressing are deformed and “ironed out” by the action of the pressing force, so that a flat and parallel upper side 7 and lower side 8 are produced. The boards 2 are preferably profiled in such a way that an overthrust 12 between adjacent boards 2 only occurs due to the dimensioning of the folding profile 9 . For the sake of completeness, Fig. 2 shows overhangs 12 on adjacent boards 2, which are caused by the design of the folding profile 9 and the dovetails 13. Also in the embodiment of the wood composite panel 10 according to FIG. 2 only the application of a surface pressure FD is required, but not an additional lateral pressure.

With reference to Figure 4, the single-layer wood composite panel 10 can alternatively be used as a two-layer wood composite panel 20, a three-layer wood composite panel 30 or as a wood composite panel with more than three layers, for example four, five, six, seven, eight, nine, ten or more than ten layers , be educated. The upper side 7 of the wood composite panel 10, 20 or 30 consists of the outer visible surfaces of the uppermost layer of pairs of boards 14 of interconnected boards 2 and the underside 8 of the wood composite panel 10, 20 or 30 consists of outer visible surfaces of the lowermost layer of pairs of boards 14 of interconnected ones Boards 2 formed. In the case of a three-layer composite wood panel 30, a middle layer panel 15 can be formed from side boards, center boards, center planks, squared timber planks, cross timber planks and/or center planks of a block-shaped substrate 3. It should also be mentioned that the thickness of the individual layers of the wood composite panels can be relatively small, e.g. only 20 mm thick. Such thin layers are called lamellae, which are processed into multi-layer panels that have high rigidity and strength. It has been shown that the quality of these multi-layer panels is higher when pairs of planks are used instead of individual planks.

5A and 5B show two boards 2 joined to form a pair of boards 14, for example that according to FIG. 3, in a mixed perspective view, the dovetail profile 13 for connecting the boards 2 being shown inserted in each case. The boards 2 are profiled with respect to each other without overthrust, and the Guide chamfers 17 serve as stops for the formation of further dovetail profiles for connecting pairs of boards 14 by means of the dovetail profiles at the longitudinal connections 13.

FIG. 6 shows a method for producing such a pair of boards 14 from boards 2. The method is particularly effective and can be carried out inexpensively. The two boards 2 represent a "right" and a "left" side board of a block-shaped substrate 3, for example a raw log, as described above. One of the boards 2 is then turned, and the longitudinal narrow sides 5 of the boards 2 to be connected are each profiled with opposite dovetail profiles 13, the boards 2 being guided along a guide chamfer direction 16 at the stop of guide chamfers 17 which are milled into the boards 2. The boards 2 are preferably profiled while the boards 2 are fresh. The boards 2 are then connected, preferably while still wet, with or without PU adhesive to form the pair of boards 14 by sliding the complementary partners of the dovetail profiles 13 into one another. Sliding the boards into one another 2 takes place in relative speed to one another, ie the boards 2 can be moved in opposite directions, or one of the boards 2 can be at a standstill, or the boards 2 are moved in the same direction at different speeds. If gluing takes place when fresh, the gluing on the longitudinal narrow sides 5 can be optimized by using microwaves in order to promote a uniform reaction in the glue joint. Each pair of boards 14 is connected along its center and can be profiled on the remaining outer longitudinal narrow sides 5 with one or more folding profiles 9. Before further joining and pressing to form a composite wood panel 10, 20 or 30 according to the invention, the pairs of boards 14 are preferably dried. Optionally storing the pairs of boards 14 in a warm/heated environment aids the reaction in the glue line. The fact that the boards were profiled and joined when fresh can be seen from the shrinkage behavior. The fact that the boards come from the same tree on opposite sides can be determined by analysis, e.g. based on their very similar knot formation in the knot pattern of the board surfaces with the intervals of the annual growth, their comparable density, similar annual ring patterns with approximately the same annual ring widths, the same humidity that is usual in the tree trunk and the same Quality, as well as comparable shrinkage behavior recognizable. The dovetail connection creates a positive connection between the boards 2. The two boards 2 of the pair of boards 14 are preferably arranged in a neutral annual ring position with respect to one another.

The width of each board 2 at its narrow end is at least 30, preferably at least 40 mm, at least when it is stripped by the saw, with the board width preferably being able to be selected as large as possible, e.g. in 1 mm increments.

An embodiment of a method according to the invention for the production of a wood composite panel 1, 10, 20 or 30 is described below by way of example:

In a first method step, several boards 2 are provided. Two adjacent ones of the boards 2 provided are made from the same block-shaped substrate 3 and are cut in particular while the substrate 3 is still fresh, which is preferably a tree trunk cut to a standard length of raw wood, and are joined together to form pairs of boards 14, as described above .

In a next process step, each board 2 is profiled while still fresh along its longitudinal narrow sides 5 with profiles which, according to the above description, have at least one dovetail profile 13 and/or one or more folding profiles 9 with a folding profile angle SW of less than or equal to 90 angular degrees. If pairs of boards 14 are provided, the boards 2 of these pairs of boards 14 are connected to one another along their contacting longitudinal narrow sides 5 via at least one dovetail profile 13, and the pairs of boards 14 are each profiled along their outer longitudinal narrow sides 5 with a profile which, according to the above description has one or more folding profiles 9 with a folding profile angle SW of less than or equal to 90 degrees. The folding profiles 9 can be milled, with a narrow edge preferably being pre-milled as a guide chamfer 17 on the narrow longitudinal sides 5 in the wider area of the board 2 or pair of boards 14, which can then serve as a stop for the milling process of the folding profiles 9 (see Figure 6 ). The dovetail profiles 13 and the folding profiles 9 must be verified in the finished products at all times. The profiling of the boards 2 is preferably carried out on their longitudinal narrow sides 5 with circular saw blades with a bevel cut, e.g. with a bevel cut of 15 angular degrees both for the production of dovetail profiles and folding profiles 9 with folding profile angles SW of 15 or 75 angular degrees.

A layer of adhesive is then applied to the lateral profiles of the longitudinal narrow sides 5 . In a further process step, the pairs of boards 14 are arranged mirrored to one another in relation to the central transverse axis 6 and are bonded together in a press under the effect of only surface pressure FD on the upper side 7 and/or the underside 8 of the wood composite panel 1, 10. The so-called "carpet" formed in this way can essentially be produced indefinitely. Pairs of boards 14 can also be placed in several layers one on top of the other with the application of adhesive to their mutually facing upper and lower surfaces and then pressed together by surface pressure. What is new compared to the prior art is that this manufacturing process can take place in just one step.

The pairs of boards 14 of the composite wood panel that are connected to one another on their longitudinal narrow sides 5 are preferably aligned in such a way that adjacent pairs of boards 14 are arranged in a neutral annual ring position.

The process steps described can optionally be repeated as often as desired to produce further layers. The layers are preferably placed parallel to one another and glued to form a composite wood panel 20 or 30 . The surfaces of the layers formed can be bonded in the rough sawn state, i.e. without prior surface smoothing, if a suitable press is used, e.g. a press that offers pressure equalization through oil filling.

The wood composite panel 1, 10, 20 or 30 produced as described above can be cut to length in width along at least one sawing direction, preferably essentially parallel to the longitudinal narrow sides 5. In addition, the cut-to-length composite wood panel 1, 10, 20 or 30 can be glued to other composite wood panels and/or galvanized along its narrow width sides 18.

The production of a composite wood panel 1, 10, 20 or 30 according to the method described above enables low production costs and high yields that have not been achievable up to now. The production of composite wood panels 1, 10, 20 or 30 according to the invention is preferably carried out with a high-frequency press, with subsequent dividing and/or finger-jointing enabling the production of a wide variety of products, for example single or multi-layer cross laminated timber panels or beams for the wooden structure.

A further embodiment according to the invention of a single-layer composite wood panel 50 is shown in cross-section in FIGS. 7 and 8 . The wood composite panel 50 consists of Boards 22, wherein two boards 22 are combined into a pair of boards 24 and adjacent pairs of boards 24 are connected to each other. The term "board" as used herein also includes "planks", which are boards with greater thicknesses. The boards 22 have profiles in the form of dovetails 13 along their narrow longitudinal sides 5, with the dovetail profiles 13 of adjacent boards 22 facing one another being designed to be complementary to one another, so that two boards 22 are connected to form a pair of boards 24 by sliding the dovetail profiles 13 into one another. The boards 22 have a trapezoidal cross section transverse to their longitudinal extent, in which the longitudinal narrow sides form the legs of the trapezoidal cross section, the boards 22 being in relation to a central transverse axis

6 are arranged mirrored to one another. It should be noted that the embodiment of Fig.

7 shows overhangs of the boards 22 on some of the dovetail profiles 13, however, this composite wood panel 50 can also be manufactured without overhangs, as shown by the embodiments according to FIGS. 9A and 9B.

The outer longitudinal narrow sides 5 of each pair of boards 24 have at least one dovetail profile 13, the dovetail profiles 13 being shaped in such a way that the dovetail profiles 13 formed on the outer longitudinal narrow sides 5 complement one another when adjacent pairs of boards 24 are connected, or in other words are designed to be opposite or complementary are.

In the embodiment of the wood composite panel 50 shown in Fig. 7 and Fig. 8, the dovetail profiles 13 on the longitudinal narrow sides 5 of the facing boards 22 of each pair of boards by about 0.1 mm to 0.8 mm, preferably by about 0.3 mm to 0.6 mm, particularly preferably by about 0.4 mm to 0.5 mm, spaced from the central transverse axis 6, which results in an overthrust when connecting the adjacent boards 22 on the longitudinal narrow sides 5 facing one another. This overthrust is leveled out by surface pressing of the pair of boards 24, with the dovetail profiles 13 wedging into one another and thereby creating a better connection. The boards 22 can be connected to one another in the wet, ie undried, state. In the embodiment of the composite wood panel 50 shown in FIGS. 7 and 8 , the external dovetail joints 13 of the pairs of boards 24 are not offset from the central transverse axis 6 . This saves the use of a press when connecting pairs of boards 24 . However, it is preferable, for example for load-bearing applications, to connect only dry pairs of boards 24 to one another. It should be noted that in other embodiments of the composite wood panel 50 according to the invention, the outer longitudinal narrow sides 5 of the pair of boards 24 to about 0.1 mm to 0.8 mm, preferably about 0.3 mm to 0.6 mm, particularly preferably about 0.4 mm to 0.5 mm, are spaced from the central transverse axis 6, whereby when connecting adjacent Pairs of boards 24 on the facing longitudinal narrow sides 5 results in an overthrust, which is leveled out by pressing using a press.

Fig. 8 shows a single-layer wood composite panel 50 according to the invention, in which the connecting dovetail profiles 13 can already be produced at the tree edge of side boards and also for boards and planks from the entire trunk with an angle of 25° to 90°, e.g. with the Measurement data of the boards 22 and/or the pairs of boards 24. The wood composite panel can, preferably in the fresh state, be divided into standard widths (shown as dashed lines as exemplary widths A, B, C), e.g. in a 2 cm grid, whereby wood composite elements in grid 6, 8, 10, 12, 14, 16, . . . up to about 40 cm can be made available. The splitting of the composite wood panel 50 is preferably carried out lengthwise approximately in the middle of the width of the boards 22, which can be followed by a drying process.

It should be mentioned that all embodiments of the composite wood panels and pairs of boards according to the invention can be subjected to additional processing steps depending on the intended use, in particular a calibration of their thickness to the same thickness by planing, milling and/or grinding.

9A shows a cross-section of a three-layer composite wood panel 60 according to the invention, which is composed of three superimposed, single-layer composite wood panels 50 by means of gluing. The single-layer wood composite panels 50 are similar to those of FIGS. 7 and 8, with the difference that none of the dovetail profiles 13 are spaced from the central transverse axis 6 and therefore have no overthrust. The overlap-free composite wood panels 50 already have the required formats for the composite wood panel 60 and can be stacked and glued without any problems, without a residual board to be cut off protruding at the edge of the composite wood panel 60 . It should also be noted that the central wood composite panel 50 is arranged transversely (crosswise) to the outer wood composite panels 50, as a result of which the three-layer wood composite panel 60 forms cross-laminated timber. It is also possible to produce multi-layer composite wood panels 60 with five, seven, nine, etc. layers as cross-laminated timber. The top 7 of the top single-layer composite wood panel 50 and the bottom 8 of the bottom single-layer composite wood panel 50 represent the outer visible surfaces of the three-layer composite wood panel 60. The middle single-layer composite wood panel 50 can cost-effectively consist of side boards, center boards, center planks, squared timber planks, cross timber planks and/or center planks of a block-shaped substrate 3 .

FIG. 9B shows a variant of the wood composite panel 60 of FIG. 9A, in which the boards of each pair of boards are connected to one another by folding profiles 9 instead of dovetail profiles 13. FIG. The wood composite panel 60 can be pressed in one work step.

Fig. 10 shows in cross section a board 2 which has been cut as a thick side board from a substrate 3, namely a tree trunk in the fresh state. The tree trunk has a stick end 3a, a middle 3b and a plait 3c, which is the end at the top. The cross-sectional view of the board 2 comes from the center 3b of the tree trunk. The board 2 has been provided with a folding profile 9 on the left and several dovetail profiles 13 on the right at its waney edges WK (which are also referred to as tree edges and represent that part of the board on the tree circumference), with adjacent dovetail joints 13 being formed in the opposite direction to one another. In order to illustrate the excellent utilization of the tree volume by this configuration of the board 2, two rectangular boards 30, 31 have been drawn inside the board in a thin line, as they are in cutting methods according to the prior art as side boards with a wide kerf between the boards 30, 31 and lots of sawdust next to the boards 30, 31.

11 shows in cross section another board 2 which has been cut as a thick side board from a substrate 3, namely a tree trunk in the fresh state. This board 2 differs from the board 2 of FIG. 10 only in that several dovetail profiles 13 are milled into the left and right of the wane.

12 shows, in cross section, another board 2 which has been cut as a thick side board from a substrate 3, namely a tree trunk in the fresh state. This board 2 corresponds to the board 2 of FIG. 11, demonstrating that with thick tree trunks and correspondingly wide boards 2, the board 2 can be divided lengthways by longitudinal cuts along cutting lines 2d, 2e, so that an inner board 2a with a rectangular cross-section and smooth side surfaces and two edge-side boards 2b, 2c, which each have a wane as a side surface, into which several dovetail profiles are milled. 13 shows a cross-section of a pair of boards 14 consisting of two boards 2 connected to one another by two dovetail profiles 13 configured inverted to one another, in each of which a guide chamfer 17 is milled on their outer side edges, the two guide chamfers 17 being aligned parallel to one another. Furthermore, a preferred design of the dovetail connection for thinner side boards of eg 20, 25, 30 mm is shown, where a mechanical form fit with force fit can already be produced by designing a wider design of the root and especially in the middle also in the head height. A difference in head height can also be formed on the formable length of the wedge bevel as shown, showing the connection on the pair of boards by a folding profile to the panel. The advantage of the inverted formation of dovetail profiles according to the invention is also that breaking off or chipping off of dovetail parts in the groove at the more acute dovetail corner can be avoided.

14 shows a front view of a tree trunk seen from the plait side, from which it can be seen that, according to the invention, several side boards SI, S2, S3, S4 and side boards S1′ are arranged opposite them in the same position in relation to the central axis M of the tree trunk. , S2', S3', S4' are cut off. The longitudinal section of the side boards S1, S2, S3, S4, S1', S2', S3', S4' is parallel to the shell, so that each side board has a constant thickness. After all the side boards have been cut off, a center plank Z remains with a thickness that increases over its length. The mutually opposite side boards S1 and S1', S2 and S2', S3 and S3', S4 and S4' form joining partners, which are joined together to form pairs of boards after the formation of profiles at their waney edges WK. It can be seen from this figure that the wane WK, which forms the side surfaces of the side boards, are at different, sometimes very acute angles to the base surface and the top surface of the side boards, which means that the top surfaces on the outer side boards S4, S4' are less conical are almost parallel and also stand in a similar slant at the tree edge on the plait (pointed) and stick (steep), whereby a maximum yield can be achieved. The deforestation, or conical rejuvenation of a tree, is the decrease in the diameter of a trunk towards the crown of the tree. Also on the other boards S3, S2, S1, the top surfaces are less conical than in the prior art. As a result, the generation of cheaper sawmill by-products (splinters and wood chips for the paper and wood-based materials industry) can be reduced by at least a third. In prior art designs, such sideboards were considered inferior because of their sloping side surfaces. However, according to the invention, they provide one High-quality wood raw material for the production of pairs of boards and wood composite panels.

Fig. 15 shows a cutting pattern through a substrate 3 in the form of a fresh tree trunk, e.g. with a diameter of at least 40 cm at the plait, the cutting pattern being shown from the outside up to the central plank Z of the tree trunk, but the lower half of the cutting pattern, which is not shown, is symmetrical to the top half of the pattern. In the drawing - viewed from top to bottom - a thick side board 2 has first been cut off, the outside (waney edge side) side surfaces of which are preferably profiled on one side with several opposite dovetail profiles 13 while the cut board 2 is still fresh and on the other side be profiled with a folding profile 9. The drawing shows how this board 2 is joined to form a pair of boards 14 with a board 2' cut off in the same position from the opposite side of the central axis M of the tree trunk and also provided with dovetail profiles 13 and a folding profile 9, in that the two boards 2 are plugged into one another in the longitudinal direction with their dovetail profiles 13 . It can be seen in this representation that the two boards 2 have been arranged in a neutral annual ring position in accordance with the trade rule, ie that the curvature lines of the annual rings of the two boards 2 run in opposite directions to one another. This uppermost cut-off side board 2 corresponds to the side board 2 shown in FIG. 10. Following this first side board 2, a second side board 2 is cut off, which is profiled with dovetail profiles 13 on both sides of the wane. This side board 2 corresponds to that of FIG. 11. Since this side board 2 is already very wide, it is divided twice in length so that narrower side boards 2b, 2c and a middle board (heartwood plank) 2a are obtained. Fig. 15 also shows how the outer side board 2c with a board 2b' cut off in the same position from the opposite side of the central axis M of the tree trunk and also provided with dovetail profiles 13 in a neutral annual ring position from board 2c with board 2b to a predominantly sapwood 2b' containing pair of boards 14 can be assembled. A third board 2, closer to the center, is already so wide that it can be divided into a total of five boards, with three planks or slats as middle boards. Finally, a center plank Z is cut out from the substrate 3, which contains the wedge-shaped heartwood in the central axis M. This central plank Z is divided into a total of nine trapezoidal boards ZI, Z2, Z3, Z4, Z1', Z2', Z3', Z4', FIG. 15 also showing how two each other in the same position in the Center plank Z opposing squared timbers ZI and Z1', Z2 and Z2', Z3 and Z3', Z4 and Z4' by forming dovetail profiles 13 in the radial annual ring and nesting along the dovetail profiles 13 in neutral annual ring position can be connected to each other again in parallel to form pairs of boards, in addition to the positive fit through the dovetail profiles 13 also gluing can take place. In this way, the tree trunk is used with the least possible amount of sawmill residue, and high-quality parallel pairs of boards and squared timber are produced from them, and only pairs of boards that are connected in parallel again leave the saw, which, as described above, can be processed further. If, for example, the boards 2b and 2c of the wide boards/planks (eg as 2a/2b/2c in FIG. 15) are connected to one another in the fresh state by means of dovetail profiling 13, board pairs 14 are already obtained in the finished figure and dimension.

16A to 16F show the production of pairs of boards and composite wood panels made from thin tree trunks, so-called weak wood, in a schematic representation. First, the thin tree trunk is divided lengthwise into two halves, which form the two - almost semi-circular - boards 2, 2. A core wedge such as in the embodiment of FIG. 15 is not formed upon splitting. On the opposite sides of the boards 2,2 guide chamfers 17 are formed along the length of the boards 2,2. This condition is shown in Fig. 16A. Then, in both boards 2, 2, dovetail profiles 13 are formed along the length of the boards 2, 2, see Figure 16B. In the subsequent processing step, shown in FIG. 16C, the left board 2 is turned around its transverse axis and then rotated lengthwise through 90° clockwise. The right board 2 is not turned, but is also rotated lengthwise 90° clockwise. As a result, the dovetail profiles 13 of the two boards 2, 2 face each other. In the next step, shown in FIG. 16D, the two boards 2, 2 are pushed into one another lengthwise at the dovetail joints 13, as a result of which the two boards 2, 2 joined together form the board pair 14. The assembly can, but does not have to be done with the help of glue. Pressurization after telescoping is not necessary. In the next step, shown in FIG. 16E, further dovetail profiles 13 are formed on the sloping longitudinal sides of the pair of boards 14 . With the help of these dovetail profiles 13 on the sloping longitudinal sides, the pair of boards 14 can be connected lengthwise to other pairs of boards 14 of the same type to form a composite wood panel 1 of any width, in that the pairs of boards 14 are pushed into one another on the dovetail profiles, optionally with the aid of adhesive. Pressurization after assembly can be done, but is not necessary. The wood composite panel 1 thus produced is shown in Fig. 16F. It can be seen that both the boards 2 of each pair of boards 14 and the adjacent pairs of boards 14 are each arranged in a neutral annual ring position. 17A to 17F show the production of pairs of boards and composite wood panels made from thin tree trunks, so-called weak wood, in a schematic representation. The steps of the manufacturing process shown in Figs. 17A to 17D correspond to those shown in Figs. 16A to 16D. For explanation, reference is made to the above description of Figs. 16A to 16D. In the next step, shown in FIG. 17E, folding profiles 9 are formed on the sloping longitudinal sides of the pair of boards 14 instead of dovetail profiles. With the help of these folding profiles 9 on the sloping longitudinal sides, the pair of boards 14 can be connected lengthwise to other pairs of boards 14 of the same type to form a composite wood panel 1 of any width by hooking the pairs of boards 14 into one another on the folding profiles, optionally with the aid of adhesive, and then applying surface pressure is exercised. The wood composite panel 1 thus produced is shown in Fig. 17F. It can be seen that both the boards 2 of each pair of boards 14 and the adjacent pairs of boards 14 of the composite wood panel 1 are each arranged in a neutral annual ring position. The boards 2 and pairs of boards 14 are joined together when the wood is fresh.

The production of a pair of boards according to FIG. 13 is shown in FIGS. 18A to 18E. First, two boards 2 are cut as side boards from a tree trunk by means of an incision parallel to the jacket, the boards being cut at corresponding positions of the tree trunk that are opposite one another with respect to a longitudinal axis of the tree trunk, see FIG. 18E. Guide chamfers 17 are formed on the side surfaces of the boards 2, see Fig. 18A. A dovetail profile 13 is then milled on one side surface of each board 2, see FIG. 18B. Next, a board 2 (the left board 2 in the drawing) is rotated by 180° about its longitudinal axis. The two boards 2,2 are thus in opposite, i.e. neutral growth ring positions and with dovetail profiles facing each other, see Fig. 18C. The two boards 2, 2 are now pushed into one another lengthwise at their dovetail profiles 13 while they are still fresh, i.e. moist, and thus form the pair of boards, as shown in Fig. 18D.

Claims

24 patent claims:

1. Pair of boards (14) consisting of two boards (2) connected to one another along their narrow longitudinal sides (5) profiled in the longitudinal direction (4), the profiling being a profiling that has already taken place in the sawmill when the boards (2) are fresh, characterized in that that the boards (2) come from the same tree trunk, preferably from the same tree trunk cut to standard raw wood length, with essentially the same moisture content and conicity and are cut from corresponding layers of the tree trunk lying opposite one another in relation to a longitudinal axis of the tree trunk, with a Guide bevel (17) is formed on the boards (2) to be connected, the two boards (2) having been connected in the fresh state of the boards (2) and the two boards (2) being arranged in a neutral annual ring position with respect to one another.

2. pair of boards (14) according to claim 1, characterized in that the pair of boards is provided on its two narrow longitudinal sides with mutually parallel guide chamfers (17).

3. Pair of boards (14) according to one of the preceding claims, characterized in that the profiling of the boards (2) on the common longitudinal connection are designed as complementary dovetail profiles (13), the longitudinal connection optionally being provided with an adhesive, and with preferably if several dovetail profiles (13) are formed on each board, adjacent dovetail connections (13) are formed opposite to one another, for example for each e.g. approx. 10 mm of the board thickness, with the dovetail profiles (13) preferably being milled in the curve of the tree edge.

4. pair of boards (14) according to any one of the preceding claims, characterized in that the geometry of the dovetails in the tangential wood of the annual rings in the round tree edge at the root of the tails, preferably in a minimum width of 6 mm, in higher strength for heavier loads Transverse forces are carried out, with the central dovetails being approximately twice as high as the laterally outer dovetails in the curve of the tree edge, with preferably dovetails in the standing wood of the radial annual rings in the trapezoidal central plank, e.g. the trapezoidal boards (Z with Z'), are about 3 mm wide and about 2 mm high at the root.

5. Pair of boards (14) according to one of the preceding claims, characterized in that the width of each board (2) at its narrow end, at least striped by the saw, is at least 30 mm, preferably at least 40 mm, with the board width preferably being as large as possible, e.g. can be selected in 1 mm increments.

6. pair of boards (14) according to any one of claims 3 to 5, characterized in that the boards (2) are profiled without overthrust in relation to each other with dovetail profiles (13) and by telescoping the boards (2) on their dovetail profiles (13) without Pressure are connected to each other to the pair of boards (14).

7. pair of boards (14) according to claim 6, characterized in that on the longitudinal narrow sides (5) of the pair of boards dovetail profiles (13) for connecting pairs of boards (14) are formed.

8. pair of boards (14) according to claim 6, characterized in that folding profiles (9) are formed on the longitudinal narrow sides (5) of the pair of boards (14), which are preferably dimensioned such that when assembling pairs of boards (14) by means of the folding profiles (9) an overthrow (12) of preferably 0.3 to 0.6 mm in height results and this overthrow (12) disappears when pressure is applied.

9. Pair of boards (14) according to one of the preceding claims, characterized in that the boards (2) of the pair of boards (14) are formed as the two halves of the divided round timber by longitudinally halving a round timber without a core wedge or core board in the fresh state and using dovetail profiles ( 13) are connected in parallel in a neutral annual ring position.

10. Wood composite panel (10) of pairs of boards (14) connected to one another on their longitudinal narrow sides (5) according to one of the preceding claims, wherein adjacent pairs of boards (14) are arranged in a neutral annual ring position.

11. Wood composite panel (20, 30) according to claim 10 made of at least two superimposed layers of pairs of boards (14), characterized in that the pairs of boards (14) of a respective layer are provided with adhesive on their profiles and on the surfaces of adjacent layers of pairs of boards ( 14) adhesive is applied, the pairs of boards (14) of a respective layer being arranged parallel to one another.

12. Wood composite panel (60) according to claim 10 made of at least three superimposed layers of pairs of boards (14), characterized in that the pairs of boards (14) of a respective layer are provided with adhesive on their profiles and on the surfaces of adjacent layers of pairs of boards (14) Adhesive is applied, wherein the pairs of boards (14) of adjacent layers are arranged crosswise to each other.

13. A method for producing a pair of boards (14), in particular a pair of boards according to one of claims 1 to 9, characterized by the cutting of two boards (2) from the same tree trunk, preferably from the same tree trunk cut to standard raw wood length, in the fresh state of the tree trunk from corresponding layers of the tree trunk lying opposite one another in relation to a longitudinal axis of the tree trunk, forming profiles on at least one of the longitudinal narrow sides (5) of the boards (14) when the boards are fresh, arranging the two boards (2) , so that the boards (2) are mirrored to each other with respect to a central transverse axis (6), and connecting the boards on the longitudinal narrow sides (5) by sliding them into one another along their profiles, preferably when the boards (2) are fresh, optionally with prior application of adhesive, in particular PU adhesive, on the profiles.

14. A method for producing a pair of boards (14) according to claim 13, characterized in that the pair of boards is provided on its two longitudinal narrow sides with guide chamfers (17) parallel to one another, and that the two boards (2) are arranged in a neutral annual ring position in relation to one another .

15. A method for producing a pair of boards (14) according to claim 13 or 14, characterized in that the profiling of the boards (2) on the common longitudinal connection (13) are formed as mutually complementary dovetail profiles, preferably with the formation of several dovetail profiles on each Board (2) adjacent dovetail joints are formed inversely to each other.

16. Method for producing a pair of boards (14) according to one of claims 13 to 15, characterized in that the boards (2) are profiled in relation to one another without overfeeding and the guide chamfers (17) as stops for the formation of dovetail profiles for the connection of Pairs of boards (14) are formed at their longitudinal connections (13) by means of dovetail profiles. 27

17. A method for producing a pair of boards (14) according to any one of claims 13 to 15, characterized in that each board (2) is provided with a guide bevel (17) in the fresh state and the boards (2) in the dry state on their longitudinal narrow Sides (5) are profiled with complementary folding profiles (9), preferably with a 0.3 to 0.6 mm overlap of the folding profiles.

18. A method for producing composite wood panels from pairs of boards (14) produced by the method according to one of Claims 13 to 17, characterized by: pressing the pairs of boards flat, forming mutually complementary inclined profiles with folding profiles (9) in opposite shapes on the facing ones Narrow long sides of the pairs of boards (14), arranging the pairs of boards (14) next to each other, applying adhesive to the narrow long sides of the pairs of boards (14), joining adjacent pairs of boards (14) on their long narrow sides, optionally with simultaneous hooking in of the folding profiles (9 ), and pressing the mated pairs of boards (14).

19. A method for producing composite wood panels (20, 30) according to claim 18, characterized in that the composite wood panels are constructed in at least two layers by arranging the pairs of boards (14) in at least two superimposed layers and connecting them to one another, the pairs of boards in each layer are arranged parallel to each other and the adjacent layers are glued together over a large area in the same work step.

20. A method for producing composite wood panels (20, 30) according to claim 19, characterized in that several multi-layer composite wood panels are connected to one another in panel width or in predefined required widths or system width by means of finger jointing, the wood composite panels being stacked in at least two layers, with initially to produce the pairs of boards, the boards are sorted knot-free in raw wood length or parts of the boards with knots are cut off, and the multi-layer wood composite panels are cut into glued squared timber.