CH712472A2 - Method for producing wood panel elements, panel elements and use thereof. - Google Patents

Abstract

Plate elements (1) with two large surfaces and peripheral faces are made of a first wood material (4) in the form of layered solid wood having a substantially homogeneous density of more than 350 kg / m 3 and a second wood material (5) in the form of a Layer with a void fraction produced, wherein the average density of the layer of the second wood material (5) is less than 270 kg / m 3. Layers of the first and second wood materials (4, 5) are stacked together with adhesive bonds between the successive layers. In this case, at least one layer of the second wood material (5) is arranged as a coherent layer in the form, as was produced or provided with cavities, between two layers of the first wood material (4). The two large surfaces are formed by layers of the first wood material (4).

Description

Description: The invention relates to a method for the production of wooden panel elements according to the preamble of claim 1, to a panel element according to the preamble of claim 10 and to the use of panel elements.

The present invention is in the field of materials made of wood. Wood materials are mainly used in the construction and furniture industry.

For plate-shaped materials made of wood, the wood used is crushed starting from logs and then used to build up Platen elements. The size and shape of the wood parts used for building are very different. The largest wooden parts used include lumber, especially boards and veneers. Small pieces of wood used are wood chips of various sizes, wood chips, wood wool, wood chips, wood fibers and dusts. The wood parts used can be held with binders or adhesives in the plate-shaped material. Instead of small pieces of wood, other lignocellulosic materials such as cereal straw and hemp shives are used in special materials.

The properties of wood-based materials vary greatly with the size and shape of the wood particles used. Compared to solid wood, a number of properties change during the comminution of the wood. With increasing digestion or with smaller pieces of wood used, the homogeneity of the material may increase and the mechanical strength of plate elements may decrease. For example, the stability of glued laminated timber is usually higher than that of chipboard.

Wood materials can be differentiated due to the different wood parts used in materials based on solid wood, such as solid wood products or veneer products and in chipboard, fiber materials and composites. Solid wood includes wood based on boards or sticks. Veneer products are based essentially on thin veneer layers, in particular on peeled veneer. Solid wood and veneer wood materials differ essentially in terms of the thickness of the wood elements used, according to both can be made both as plywood from each with 90 ° twisted fiber directions bonded layers or as plywood with layers with substantially parallel aligned fibers. The density of solid wood products without cavities is in the range of the densities of the wood species used for the production. The density of the common types of wood is clearly above 350 kg / m3, in particular also over 400 kg / m3.

Board plywoods are mainly used as load-bearing wall, floor, roof or ceiling panels. Glued laminated timber and other board stack constructions in which the fiber orientation of the board layers is predominantly rectified, are mechanically different in the two orthogonal surface expansions. In the case of the known solid wood materials, the quality of the wood used, the type of connection and the layer structure have an influence on the strength properties of the material.

Wood chipboard materials are made of wood chips, synthetic resin glue and additives under heat and pressure and have densities above 350 kg / m3. The wood chips are obtained with hackers and special chipper knives made of solid and sawed wood. Wood chipboard materials are used for many different applications. Accordingly, there are a variety of classification features, by manufacturing, surface, shape, size, structure or purpose.

Wood fiber boards are made of wood, sawmill by-products or leftover wood, but also from other fibrous plants such as flax or rapeseed. The structural cohesion is based essentially on the entanglement of the wood fibers and their natural binding forces, but adhesives can also be used as binders. Depending on the manufacturing process, for example dry or wet web formation, and compaction of the wood fibers, a distinction is made between subgroups.

[0009] Known fiberboards produced by the wet process include wood fiber insulation boards (HFD) having a density in the range of 270-350 kg / m3, medium-hard fiberboards (MB) having a density of 350 to 800 kg / m3, and hard fiberboard (HB or HFH) with a density above 800 kg / m3. For medium density fiberboard (MDF) and high density fiberboard (HDF) produced by dry process, the densities are equal to or higher than the densities of the wet process plates.

EP 1 674 224 B1 and WO 99/22 084 A1 describe the production of wood fiber insulating elements, wherein fiber material is applied to a conveyor belt and connected to a fiber mat. The mechanical strength and substitutability of these insulating elements are limited and insufficient for many applications.

WO 95/32 082 A1 describes a timber component with layers bonded to one another, the layers being constructed of boards which each have a grooving on mutually facing main surfaces. The boards of two directly adjoining layers are aligned transversely and diagonally to each other. At the contact surfaces of adjoining layers, foreign material in the form of a foam-glue mixture as a filler can be arranged in cavities formed by grooves that are substantially closed off from the outside.

From the documents EP 1 913 211 B1, WO 2010/028 416 A2, WO 2010/022 427 A1 and WO 2010/129 983 A2 wood materials are known in which in a first step of the production at least two layers of grooved boards are interconnected, wherein the grooves of two successive layers run transversely to each other. From the resulting plates strips are separated, the strips are folded 90 ° about their longitudinal axis and connected together to form a new plate. In the new plate, the fiber direction and the groove longitudinal axis of the sections of the grooved boards are transverse to the two large plate surfaces. The grooves extend with a large groove cross-section substantially over the entire width of the sections of grooved boards, which is disadvantageous due to the large individual cavities in the plate with respect to thermal insulation. Already the production of the simplest described plate is complex, because first an originally contiguous layer of boards with grooves divided and differently reassembled and connected must.

From WO 2015/155 105 A1 lightweight components with a lightweight panel and one of the lightweight board associated layer of insulation material are known. The lightweight board is composed of layers of boards with parallel grooves in their major surfaces, the grooves of directly adjacent layers are connected by arranged in raster-shaped areas overlapping groove openings to a large contiguous cavity, which is disadvantageous for the thermal insulation. In producing a described insulation material wood chips are formed together with a binder to a chip mat, which is held together by the set binder. The use of this insulating material is described only for cavities, in particular between two lightweight panels.

The inventive task is now to find a manufacturing process for plate elements, plate elements and uses the same, which ensure good thermal insulation and optimal mechanical stability and operational capability for each use with little effort.

The object is achieved by the manufacturing method with the features of claim 1, by plate elements according to claim 10 and by the use of these plate elements according to claim 15.

A production method according to the invention comprises the use of at least two different wood-based materials. A first wood-based material is a layered solid wood with a substantially homogeneous density of more than 350 kg / m3. A second wood material is used as a layer with a void fraction, wherein the average density of this layer is less than 270 kg / m3. The layers of the first and second wood materials are stacked together with adhesive bonds between the successive layers to form a plate element. At least one layer of the second wood material is arranged between two layers of the first wood material. Each layer of the second wood material extends as a continuous layer in the form originally made with cavities, that is, without separation and reconnection, over the entire area of a simplest plate element. The two large surfaces of the plate element are formed by layers of the first wood material.

Layers of the first wood material and thus layers of solid wood close the adjoining cavities of the at least one layer with a void content in the simplest plate element. As a result, air movements are prevented by the layer boundaries and reduced air movements in the adjacent cavities, which increases the thermal insulation of the at least one layer with a void content. Layers of the first wood material, ie layers of solid wood, together with the adhesive joints of the layers of solid wood to each at least one layer lying between these solid wood layers of the second wood material increase the mechanical strength of the simplest plate element. The simplest panel elements have a substantially smooth and stable shape on both large surfaces, making them ideal for joining to other layers.

Preferably, the adhesive bonds between the layers of the plate member extend over the entire region of a simple plate member, wherein substantially all the contacting portions of the respective interconnected layers are connected via adhesive bonds.

In a preferred solution layers of the first wood material are used with substantially perpendicular to each other orientations of the fibers in the plate member and in particular glued together, so that the dimensional stability of the plate member is additionally increased.

In a further preferred solution, starting from a simple plate element with only two layers of the first wood material and an interposed layer of the second wood material outside of a layer of the first wood material at least one further structure with one layer of the second wood material and one each arranged on the outside subsequent layer of the first wood material and connected via a respective adhesive bond.

In order to increase the outgoing of the layers of the first wood material stability, for example, in thin layers of the first wood material, two or more than two, in particular three, layers of the first wood material disposed between successive layers of the second wood material and connected in each case via adhesive bonds become. It is advantageous if the fibers of at least two directly successive layers of the first wood material are aligned differently, in particular so that the fibers of these layers are substantially perpendicular to each other. The used second wood material, or the at least one layer with a void content, and the first wood material used, or the layered solid wood, are adapted to the particular use of the plate element.

If the plate element is used as a building board, so it must primarily ensure the highest possible mechanical stability and only in the second line a sufficiently high thermal insulation. The second wood material, or the at least one layer with a cavity portion, is therefore preferably formed by a layer of boards provided on the wide surfaces with a plurality of parallel grooves and laterally and optionally longitudinally connected boards. The longitudinal axes of the grooves are parallel to the large surfaces. The first wood material used is preferably formed by solid wood panels of small thickness, preferably in the range of 2 to 10 mm. If the stability emanating from the boards with parallel grooves is already substantially large enough, the first wood material used may also be formed of veneer, in particular peeled veneer, with a thickness in the range of 0.7 to 2.5 mm.

The two board surfaces with parallel grooves between the grooves lying web outer surfaces ensure when assembling plate elements, or when bonding a layer of the second wood material with a layer of the first wood material sufficiently large contact surfaces for a stable adhesive bond. The insertion of layers of the first wood material without grooves ensures that always all the web outer surfaces of the grooved boards are in adhesive contact with the adjacent layer of the first wood material without grooves. Regardless of the angle between the grooves and the orientation of the plate or the alignment of grooves of a subsequent layer always the same connection forces are ensured.

In addition, it can be ensured that the grooves of the second wood material are always completed in the layer of the first wood material and thus no coherent formed of a plurality of grooves cavity is formed. This is advantageous for good thermal insulation.

If the adhesive is applied to the separate web outer surfaces or on the contiguous surface of the layer without grooves, the vapor permeability is little or greatly reduced, which of course also depends on the adhesive used. The vapor permeability can be adapted to the respective needs, because a surface with and a surface without grooves are glued together.

In order to achieve a desired stability in the longitudinal and transverse direction of the plate member, this comprises in the embodiment as a building board at least two layers with grooved boards, the longitudinal axes of the grooves of these two layers at opposite equal angles to the longitudinal direction of the plate member. The number of layers with grooves depends on the desired stability and is preferably an even number before.

If the plate element is used as a building board, the fiber direction of the first wood material preferably extends in the two large surfaces substantially in the longitudinal direction along the greater extent of the plate member. In the interior of structural panels, the fiber direction of the first wood material preferably runs essentially in its transverse direction, that is to say along the smaller extent of the panel element. By using at least one layer of the first wood material with a fiber longitudinal alignment and at least one layer with a fiber transverse orientation, the risk of deformation of the building board is reduced.

If the plate element is used as a thermal insulation board, it must primarily ensure the highest possible thermal insulation and only secondarily mechanical stability. The second wood material, or the at least one layer with a void content, is therefore preferably formed by a layer of wood shavings bonded with binder. The first wood material used is preferably formed of veneer and optionally of solid wood panels of small thickness.

For thermal insulation panels, the material costs and the production cost can be kept particularly small when preferably used as the first wood material peeled veneer. In optimized production, a first layer of peeled veneer is rolled from a roll to a production line. Then sawdust sprayed with binder in a predetermined layer thickness is applied to the entire width of the continuous rotary veneer. A second layer of a rotary veneer is placed on the top of the layer of sawdust from a roll and pressed down with a second production line.

By choosing a sufficiently fast-setting binder and the corresponding feed and the corresponding distance of the production belts continuous production of a simple plate element can be achieved. From continuously formed plate element plate elements are separated at desired longitudinal intervals. In this production, the fibers of the peeled veneer run perpendicular to the direction of production or to the longitudinal direction of the resulting simplest plate elements.

To produce thermal insulation panels in standard sizes, for example, a rotary veneer strip is used with a width of 125 cm. When separating plate elements, the lengths of 250 cm and 125 cm are advantageous, so that correspondingly plate elements of 250 cm x 125 cm or 125 cm x 125 cm arise, which if necessary also to 62.5 cm X 125 cm or 62.5 cm x 250 cm or 62.5 cm x 62.5 cm can be cut. If, as will be explained later, narrow strips are separated from the plate elements, these are folded around their longitudinal axis by 90 ° and thus rejoined into plates, the cutting lines for separating strips can run parallel to the short or parallel to the long side of the plate elements. The length of the strips corresponds to a first side length of the plate elements constructed from strips. The second side length of the plate elements constructed from strips can be adapted to the respective needs by the number of connected strips.

For thermal insulation panels wood chips are preferably used, which are removed in the manufacture of boards with grooves of starting boards, the wood chips are substantially strip-shaped and flat, wavy, roll-shaped, feather-shaped or spiral and at least 80 weight percent of wood chips with chips a length in the range of 2 mm to 40 mm are formed. The wood chips together with a binder form a substantially coherent structure. The binder comprises at least a proportion of an organic binder and / or an inorganic binder, wherein the organic binder is preferably a polymer binder, in particular polyvinyl acetate (PVAc), and the inorganic binder is preferably a binder based on alkali polysilicates, in particular a mixture of sodium silicate and / or potassium silicate with lithium silicate. If high water resistance is required, binders with polyvinyl chloride (PVC) can also be used.

If the mechanical stability of plate elements to be increased, so are separated from the simplest plate elements with cuts perpendicular to their large surfaces bars, the strips folded by 90 ° about its longitudinal axis and connected together to form a new plate. In the new panel elements, the sections of layers of the first wood material and thus of layers of solid wood run as webs in normal planes to the two large surfaces of the new panel elements. The adhesive bonds between adjacent strips are formed between such webs or between sections of the first wood material, which can be achieved due to the contiguous planar contact surfaces of the first wood material with little effort very good adhesive bonds. These interconnected portions of the adjoining strips are firmly connected to the interior of the respective bar via adhesive joints with the respective subsequent layer, so that with little effort stable new plate elements can be made of interconnected strips.

In the two large outer surfaces of put together folded strips new plate elements is determined via an adhesive connection depending on a cover layer of the first wood material and thus made of solid wood. The cover layers and the webs surround strip-shaped subregions of second wood material with a void content, adhesive bonds being formed at the contact points between the first wood material of the cover layers and the webs and the second wood material. As a result, on the one hand, the stability is increased and, on the other hand, the maximum expansions of cavities are reduced and, accordingly, the thermal insulation effect is improved.

When separating the strips, the feed of the simplest plate element between two successive cuts is set, this feed corresponds to the depth of the groove. After folding by 90 °, the feed, or the depth of the groove to the thickness of the resulting plate element. It can thus be achieved by choosing the appropriate feed from any simple plate elements in the resulting plate elements any desired thickness. An extension of the resulting plate elements or an extension of their large surface is determined by the length of the strips. In the expansion of the large surface that extends perpendicularly to this expansion, the choice of the number of interconnected strips allows an arbitrary multiple of the thickness of the simplest board elements used to be achieved.

When separating the strips a sectional plane is set relative to the orientation of the fibers in the layers of the first wood material. Layers whose fibers run parallel to the cutting plane form after folding webs whose fibers are parallel to the large outer surfaces of the resulting plate elements. In the case of the resulting panel elements, these webs increase the bending stability around bending lines which run parallel to the large outer surfaces and perpendicular to the longitudinal direction of the webs. Layers whose fibers are perpendicular to the cutting plane form after folding webs whose fibers are perpendicular to the large outer surfaces of the resulting plate elements. These webs increase the stability of the large outer surfaces with respect to pressure loading of the resulting plate elements. Because the webs are held between strip-shaped portions of second wood material, the webs can absorb high loads as clamped webs, even if they have only a small thickness.

If the second wood material or the at least one layer is formed with a void fraction of a layer of grooved and mutually laterally and optionally longitudinally connected boards in the used for the separation, transfer and bonding plate elements, new plate elements arise as advantageous Furniture panels and can also be used as doors or special building panels. When used as doors, it is expedient if the edge region of solid wood is formed without grooves, so that fittings can be easily attached.

If the second wood material or the at least one layer with a void content in the plate elements used for the separation, repositioning and bonding is formed by a layer of wood chips bound with binder, new plate elements are advantageously produced as thermal insulation panels or as light construction panels. or door panels can be used. When used as a construction or door panels, the stability can be increased if the cross section of the strip-shaped sections of second wood material is reduced perpendicular to its longitudinal axis. This can be achieved by reducing the thickness of the layer with the second wood material in the simplest board elements used and / or the spacing of the successive cutting planes when strips are cut off. For use as doors, the edge portion of solid wood, rather than woodchips bonded with binder, is formed to secure fittings.

With the use of unrolled peeled veneer and cuts parallel to the orientation of the fibers of the rotary veneer and thereby perpendicular to the longitudinal direction of the simplest plate element, the fibers extend in the webs formed by the folding substantially parallel to the large outer surfaces of the new plate elements. By the

Using at least one layer of the first wood material with an orientation of the fibers in the longitudinal direction of the simplest plate element, the fibers of this layer extend substantially perpendicularly to the large ones in strips formed by separating, flipping and joining strips therefrom, which extend over the width of the plate elements External surfaces of the new plate elements, which increases their stability.

In order to increase the pressure stability of thermal insulation boards, in a preferred solution before separating strips, a stack of at least two simplest plate elements each formed with a layer of wood chips associated with binder and each formed on both sides layers of peeled veneer, wherein between the plate elements each layer of the first wood material, or layered solid wood with small thickness or veneer, in particular peeled veneer, is inserted so that their fiber direction is transverse to the grain direction of the already connected to the simplest plate elements peeled veneer of the stack. So that the layers of the stack are firmly connected, the layers of the stack are glued and pressed together.

If the simplest plate elements with square large surfaces are used to build the stack, it can be dispensed with the insertion of layered solid wood. Namely, in the stack, the simplest plate elements can be placed at 90 ° orientations of the fibers of the layers of peeled veneer. After gluing such layers with different orientation of the fibers form stable plate stacks.

If now detached from the stack strips, folded by 90 ° and connected to each other, the fibers of the inserted layers of solid wood from one to the other large surface of the new plate element. In connection with the perpendicularly extending fibers of the adjoining webs of peeled veneer composite webs with a high strength and dimensional stability. The stability can be chosen so that the resulting plate elements can also be used as floor plates. If the webs are disturbing as thermal bridges, then two thermal insulation panels can be connected to each other with mutually offset web layers, so that there are no continuous webs between the two large outer surfaces of the assembled thermal insulation board.

A lightweight component comprises at least one structural panel and a thermal insulation panel, wherein the thermal insulation panel is attached to the building panel preferably with an adhesive bond or optionally with a nail or Agraffenverbindung. The attachment can be done before assembling the lightweight elements to walls, ceilings, floors or roofs. Preferably, however, an area of a house is constructed from lightweight elements and then the thermal insulation panels are attached to the assembled lightweight construction elements. Thermal insulation panels on external facades can be provided with a desired coat of paint or plaster. On a building floor arranged thermal insulation panels can be provided with a desired floor covering.

In order to easily connect lightweight components to components such as walls or ceilings, these preferably comprise clamping devices in two end regions facing away from each other. The clamping devices can be constructed for example with threaded rods and clamping nuts and optionally a spring element, wherein the threaded rod of a lightweight component to be mounted is screwed into the thread of the clamping nut of the already mounted lightweight component. With the clamping nut, the threaded member firmly positioned in the lightweight element is then stretched until the two adjoining lightweight components are pressed together with a desired force, preferably via groove and spring arrangements engage with each other and are biased via the optionally provided spring element. In order to easily arrange the clamping devices in the lightweight components, grooves are formed in narrow end faces of the lightweight components. After inserting the clamping devices, the grooves can be covered with a wooden element. Corner areas with clamping connections in the directions of the adjoining wall sections allow the connection of two differently oriented wall sections.

Plate elements in which the second wood material, or the at least one layer with a void portion, formed of several parallel grooves and laterally and optionally longitudinally connected boards is formed, preferably comprise at least two layers with laterally bonded grooved boards, wherein the grooves in adjacent layers in particular at an angle to each other. The weakening of the boards or layers transversely to the groove longitudinal directions starting from the grooves is reduced by the layers of solid wood arranged between the layers of grooved boards. In the direction of the groove longitudinal directions, the webs formed on both sides of the grooves ensure a further high stability.

The orientations of the boards or the grooves of two directly adjoining layers are chosen so that the load capacity of the plate elements corresponds to their use. If the load capacity in the longitudinal direction of the plate elements must be as large as possible, an acute angle of at least 25 ° is selected between the slot longitudinal directions directly adjacent layers. If the load capacity should also be large in the transverse direction, an angle of 90 ° is selected between the slot longitudinal directions of directly adjoining layers. For many applications, angles in the range between 25 ° and 90 °, in particular the angles 45 ° and substantially 60 ° or 30 °, are preferred angles between the groove longitudinal directions directly adjacent to one another.

The in the processing of the boards, esp. In the formation of the grooves, removed material, or the second component is optimized directly during the removal of the function as an insulating material or insulation. For this purpose, a machining is used to be removed in the substantially strip-shaped chips. The removed chips have a distribution of chip lengths and a distribution of chip thicknesses. The removal of the chips is designed so that with the chips an insulating material can be formed, which provides a large void content with strong subdivision after the arrangement in thermal insulation panels, remains stable and retains moisture as little as possible, and allows desired mechanical loads on the plate elements formed therewith.

In the machining, the chips differ in their size composition according to the processing technique used, the type of wood used and the selected direction of the grooves relative to the fiber direction of the boards. The grooves are preferably formed with circular saw blades. The diameter of the circular saw blades, the distance of the saw teeth, the shape of the saw teeth, the peripheral speed of the saw teeth and the relative feed rate between a machined board and the at least one circular saw blade can be selected so that chips with the desired size composition arise.

Because in both major surfaces of a board several, esp. At least four grooves are arranged, these can be formed parallel with a plurality of spaced apart on a common shaft arranged circular saw blades, each board main surface is associated with a shaft with circular saw blades.

The engagement of the circular saw blades or their teeth in the boards preferably corresponds to the desired groove depth, so that the groove can be formed in one step. Optionally, the groove is formed in more than one step, wherein each substep removes a portion of the groove, esp. The groove depth.

A newly engaging in the board tooth of a rotating circular saw blade carries on its entire way to the exit from the board wood, the removed wood forms a chip. The span length depends on the curvature of the outer edge of the circular saw blade and the groove depth or the depth of engagement of the circular saw blade in the board. The chip width depends on the width of the teeth of the circular saw blade. The chip thickness or extension perpendicular to Spanlängsausdehnung and the span width depends on the relative feed rate between a machined board and the at least one circular saw blade, the distance (center angle or peripheral portion) between successive teeth and the speed of the circular saw blade from.

Preferably, teeth are used which produce flat strip-shaped chips with straight cutting lines, which often have a corrugated shape after separation and movement through the space associated with the respective tooth in the circular saw blade. When teeth are used which have curved cutting lines, the resulting chips have a curved shape transversely to their longitudinal extent, which results in that concave cavities are formed on the chips. Optionally, the cutting lines are also formed so that roll, spring or spiral chips arise, which also enclose interiors, or cavities at least partially.

Chips can also break during the removal, wherein the resulting partial chips each form a portion of the maximum expected span length. Whether the chips break or not depends, inter alia, on the shape and sharpness of the teeth and the clearances in the circular saw blade preceding them in the direction of rotation. In addition, the nature of the wood and the orientation of the groove plays a role relative to the longitudinal direction of the board or to the longitudinal direction of the wood fibers. In order to produce as many shavings in their recoverable total length, the longitudinal directions of the grooves are designed parallel to the longitudinal direction of the boards and separating saw blades with sharp teeth and the resulting chips corresponding free spaces used in front of the teeth. If only a few shavings break, the fines in the removed insulating material are very small and the span length distribution narrow.

In order to form as many chips from the removed material of a groove, the chip thickness is chosen to be as small as possible, with a minimum thickness should not be exceeded, so that the chips are still stable enough and over the largest possible length range a substantially have constant chip width. If a large number of chips is taken out of a given groove volume, then these many chips in the insulating material enable the formation of many partitions enclosed by chips in which small amounts of air, which are partially sealed off, achieve a high thermal insulation effect. The specific weight of a highly insulating insulating material is very small for chips with small thickness and is together with the introduced binder after setting below 270 kg / m3. This means that only a small amount of wood is needed to produce a certain volume of insulation material.

When editing the boards for the production of lightweight panels chips are produced not only in the groove formation. The main surfaces are planed and the sidewalls are machined with a moulder. Grooves and springs are formed on the side flanks of the boards by machining, so that the boards joined together to form a layer guarantee a good cohesion through the tongue and groove connection. The tongue-and-groove connections between the boards of a layer have the additional advantage that the layers can be loaded more quickly after the side flanks of the boards have been glued and the boards of the layer run flush along a plane. The boards or the layers are also planed plan, with further chip material is formed.

In the production of plate elements with grooved boards or layers of the total wood volume of the starting boards used remains about 40% in the plate element, 60% is obtained as removed residual material in the form of chips.

In a particularly advantageous embodiment, the chips removed from the adjacent grooves of a board are of different lengths. According to a first embodiment, the grooves are formed to different depths. Differently deep grooves can be used particularly advantageously if grooves are formed in the boards on both main surfaces. Thus, the entire Nuthohlraum in the board does not have to be smaller due to the different depths grooves, the grooves on the two main surfaces each other opposite each other may have a constant sum of the individual depths. Thus, if the groove has only a small depth at a first major surface, then the opposite groove at the second major surface may have a large depth. The wood area between these grooves will then each have a desired minimum thickness. Now, if the groove depths increase in the first major surface of the side edges of the board against the board center, so the groove depths increase in the second major surface of the board center against the side edges of the board.

In order to be able to use circular saw blades of different diameters distributed over the width of the board efficiently, in a preferred embodiment a first shaft aligned with the main surface of the boards to be machined at a first acute shaft angle et is used, at which circular saw blades increase at predetermined intervals Diameter are arranged. The first shaft lies in a plane that is perpendicular to the main surface of the boards and aligned perpendicular to the longitudinal axes of the grooves. The angle between the first shaft and the main surface and the diameter of the circular saw blades and their position on the first shaft are preferably coordinated so that all circular saw blades form substantially equal deep grooves.

Corresponding to the inclination of the circular saw blades, an angle is formed between the lateral edge surfaces of the resulting grooves and the main surface of the board. So that the grooves do not maintain the asymmetrical shape in sectional planes perpendicular to the groove longitudinal direction, a second shaft with circular saw blades is preferably assigned to the same main surface. This second wave with circular saw blades is relative to a perpendicular to the main surface standing the central longitudinal axis of the board comprehensive mirror plane mirrored to the first wave aligned with the circular saw blades and additionally arranged slightly offset in the board longitudinal direction to the first shaft.

The two shafts with the circular saw blades are coordinated so that after machining the main surface with two waves substantially symmetrical groove cross-sections are present, the groove width away from the main surface toward the interior of the board is larger. The groove opening in the main surface corresponds at least to the extent of the circular saw blades in the main surface perpendicular to the groove longitudinal direction. Between the grooves there are wooden ridges, which widen from the inside of the board towards the main face and have a broad ridge surface at the main face.

If after machining a main surface of a board with two mirror-image arranged skewed waves with different sized circular saw blades in the middle of the grooves on the Nutgründen still protruding central webs are formed, they may be advantageous for individual applications, they are for other applications but removed. To remove the same size circular saw blades are used, which are arranged at appropriate intervals on a parallel to the main surface and perpendicular to the Nutlängsrichtung shaft. After removal of the central webs arise grooves whose void ratio increases from the respective main surface against the inside, up to a central contiguous wood layer. In a preferred method, the central portions of the grooves are removed before the lateral ones.

The central contiguous layer of wood can absorb forces which are entered via the side flanks in the grooved board. After gluing layers of differently oriented grooves over an intervening contiguous layer of the first wood material, various transverse forces can be absorbed by these bonded layers. If the grooved boards are used in board elements with at least two layers with grooved boards, the coherent wood layer of the individual grooved boards can be minimally formed.

For grooves in the longitudinal direction of the boards, the webs extend parallel to the longitudinal direction of the wood fibers, which increases the stability of the webs. It is also possible to form a second family of parallel grooves at an acute angle to the first family of grooves. As a result, the web surfaces between the first grooves and of course the webs are interrupted. When assembling panel elements, there are still enough large contact areas for a stable adhesive bond to the layer of solid wood.

A versatile binder for bonding wood chips preferably comprises a proportion of an organic binder and a proportion of an inorganic binder, these two binders must be mutually compatible.

As organic binder is preferably used a polymer binder, for example polyvinyl acetate (PVAc) in the form of a solution in an organic solvent or preferably as a dispersion. Polyvinyl acetate is an amorphous, odorless and tasteless plastic with high light and weather resistance. It is flammable, but not easily flammable.

Suitable inorganic binders are binders based on alkali polysilicates. Alkali polysilicates are crystalline or, as a mixture of different silicates, glassy (amorphous) solids or water-viscous solutions. They comprise at least one of the alkali metals lithium, sodium, potassium, rubidium, cesium or francium, with alkali polysilicates with sodium and potassium being most widely used as water glass.

DE 2 652 421 A1 describes a binder based on alkali polysilicates, which consists of a mixture of sodium silicate and / or potassium silicate with lithium silicate. Even a small proportion of lithium silicate increases the water resistance in the hardened state and ensures a slightly lower pH. In addition, the efflorescence occurring in the setting of sodium water glass can be avoided with the proportion of lithium silicate.

In order to ensure rapid binding, a two-component binder with a desired setting time is optionally used. In order to ensure the most homogeneous bonding structure in a set of wood shavings, the binder must be brought as evenly as possible with as many wood chips in contact. The binder is introduced via nozzles into a material flow of the chips.

For the preparation of layers of binder-associated wood shavings, a binder with proportions of renewable raw materials is preferably used. Such excipients may include tannins, technical lignins, carbohydrates, e.g. Starch or also proteins e.g. Casein include. In combination with wood shavings, tannins, which are widespread in nature and are present both in hydrolyzable and in condensed form, are particularly advantageous. The production is mainly focused on condensed tannins, which are produced in particular from tree barks. Preferably binders with tannin and additives, for example with hexamine, are used in which only small formaldehyde emissions occur. Due to their chemical structure, tannins can be converted into high molecular weight condensation products with high curing rates. The properties of tannin resins can be improved by the addition of isocyanates.

When making the layers with wood shavings, the binder must form bonding bridges in contact areas between loosely gathered wood shavings. For this purpose, the binder is formed and supplied to the wood shavings that the wood chips are wetted sufficiently with binder and that form binder bridges between wood chips during subsequent bonding and the resulting insulation material is permeable to air. To achieve the desired wetting property, a wetting agent and / or a foaming agent and / or a solvent, in particular water, is optionally added to the binder. In order to achieve a particularly rapid setting, a two-component binder is optionally used.

In a preferred embodiment, both the chips and the aqueous binder are electrostatically charged. The two components are loaded opposite each other, so that at the meeting the charges, or the charge balance, leads to an optimal distribution of the binder over the wood chips.

The wood chips can be fed through a pipe, wherein the pipe end nozzles are assigned for the charged binder. In the production of a plate element with a middle layer of wood chips and on both sides of a layer of peeled veneer at least one carrier tape and an applicator for layered orders of the chips with the binder on the carrier belt lying peeling veneer and on a curing section a press belt is used, which the three Compress layers to the desired thickness. When passing through the curing section between the carrier belt and press belt binding bridges are formed between the wood chips and the two layers of peeled veneer so far that holds the resulting thermal insulation board together. In order to accelerate the curing, preferably heat and optionally air or UV light is supplied.

In order to inhibit the spread of a fire in burning buildings, plate elements are used for doors or walls, in which in a part of the void content of the second wood material a heat-absorbing and / or fire-retardant additive is inserted. The additive may, for example, release bound water under the action of heat or heat radiation or chemically react with elimination of water. The heat absorption or elimination of water is preferably carried out in a temperature range above 100 ° C, so that the split-off water can escape as steam. It goes without saying that any known additives can be used which delay the ignition of the plate element at high temperatures or in the event of fire or inhibit the passage of heat through the plate element.

An advantage of the present invention is that all tools necessary for the preparation of the plate elements, such as machines and the work steps to be performed are so simple that they can be performed by a short-trained workers and the mechanical complexity is reduced to a minimum , The production of the lightweight elements can be done near the place with the houses to be built.

The invention will be explained in more detail with reference to the drawing. Show

FIG. 1.2 perspective views of a simple thermal insulation panel, FIG.

3, 4 are perspective views of a simple building board,

5, 6 are perspective views of construction panels with 5 or 9 layers,

7 is an exploded view of a building board with 9 layers,

8, 9 perspective views of furniture panels,

10 is an exploded view of a furniture panel,

11.12 show perspective views of a robust thermal insulation panel,

13 is an exploded view of a robust thermal insulation board,

Fig. 14 is a perspective view of a section of a thermal insulation board.

Fig. 1 to 4 show a plate member 1, in which in Figs. 2 and 4 parts are cut out, so that the structure is better recognizable. The plate element 1 comprises two large surfaces 2 and circumferential end faces 3. The plate element 1 is made of a first wood material in the form of layered solid wood 4 and a second wood material in the form of a layer 5 with a void content.

In the embodiment according to FIGS. 1 and 2, the layer 5 is formed with a void content of wood shavings 6 bonded with binder, the wood chips 6 being indicated only schematically with black structural elements and the cavities 7 with white points therebetween. The wood chips 6 of the second wood material 5 are substantially strip-shaped and flat, wavy, roll-shaped, spring-shaped or spiral-shaped. Preferably, at least 80% by weight of the wood chips will be formed from wood chips having a length in the range of 2 mm to 40 mm. The average density of the layer of the second wood material in the form of binder-associated wood chips 6 is less than 270 kg / m3.

In the embodiment according to FIGS. 3 and 4, the layer 5 is formed with a cavity portion of a layer of laterally and optionally longitudinally connected boards 8, wherein in the boards 8 on the wide surfaces a plurality of parallel grooves 9 as cavities this layer are formed. The wood remaining from the boards 8 has a central contiguous area 8a and webs 8b leading away therefrom, the grooves 9 being formed as cavities between the webs 8b. The longitudinal axes of the grooves 9 are parallel to the large surfaces of the second

The average density of the layer of the second wood material in the form of the grooved 9 boards 8 is less than 270 kg / m3, this small density starting from boards with a density above 350 kg / m3.vorzugsweise in the range of 400 to 550 kg / m3, in particular at substantially 470 kg / m3, is achieved by the cavities formed by the grooves 9. Grooves 9 are advantageous in which the groove width is formed from the surface of the board 8 away towards the interior of the board 8 towards larger, because while a large cavity and yet a large contact surface can be provided at the board surface.

The first wood material in the form of layered solid wood 4 is shown in the embodiment of FIG. 3 and 4 as a solid wood panel with a thickness in the range of 2 to 10 mm and in the embodiment according to FIGS. 1 and 2 as a veneer with a Thickness in the range of 0.7 to 2.5 mm. The substantially homogeneous density of the layered solid wood 4 is above 350 kg / m3, preferably in the range of 400 to 550 kg / m3, for example at substantially 470 kg / m3. It goes without saying that the veneer can also be used in the embodiment according to FIGS. 3 and 4 and solid wood in the embodiment according to FIGS. 1 and 2, if the required mechanical stability is thus achieved.

The embodiments shown in Figs. 1 to 4 show plate elements 1 with layers 4 and 5 of the first and second wood material, which layers are stacked together with adhesive bonds between the successive layers. In these embodiments, a layer 5 of the second wood material between two layers of the first wood material in the form of the layered solid wood 4 is arranged. In the case of the two large surfaces 2, the layered solid wood forms 4 cover layers.

In order to keep the risk of deformation as small as possible, in the embodiment according to FIGS. 3 and 4, the fiber directions indicated by lines 4a in the two cover layers of a plate element 1 are oriented substantially perpendicular to one another. In the embodiment according to FIGS. 1 and 2, the lines 4a of the fiber directions are substantially parallel, because the layered solid wood 4 of both cover layers was unwound in the production of the plate elements of peeling veneer rolls with parallel roll axes.

Fig. 5 shows an embodiment in which a pair of layers 5 of boards 8 are inserted with grooves 9 in the plate member 1, wherein the longitudinal axes of the grooves 9 of these two layers 5 are aligned at opposite equal angles to the longitudinal direction of the plate member 1 , Layered solid wood 4 is arranged between the two layers 5 and at the two large surfaces 2 of the plate element 1, preferably in the form of a solid wood panel at the two large surfaces 2. Between the two layers 5, a layered solid wood 4 with a small thickness optionally a veneer can be arranged. It goes without saying that all layers of solid wood 4 may have the same thickness.

The fiber direction 4a of the layered solid wood 4 in the case of the two large surfaces preferably runs essentially in the longitudinal direction of the plate element 1. The fiber direction runs in the interior of the plate element 1

Claims (15)

4a of the layered solid wood 4 substantially in the transverse direction of the plate element 1. The stability of the plate element 1 can be influenced by the choice of the fiber directions. 6 and 7 show an embodiment in which two pairs of layers 5 of boards 8 with grooves 9 are inserted into the plate element 1, wherein the longitudinal axes of the grooves 9 of the layers 5 of a pair at opposite equal angles to the longitudinal direction of the plate member 1 are aligned. Between all layers 5 and at the two large surfaces of the plate element 1 layered solid wood 4 is arranged, which is clearly visible in the exploded view of FIG. 7. The thickness of the layered solid wood 4 is in the illustrated embodiment in the two large surfaces 2 larger than the solid wood 4 between the layers 5. It goes without saying that all layers of solid wood 4 may have the same thickness. In the illustrated embodiment, the fiber direction 4a of the layered solid wood 4 extends in the two large surfaces substantially in the longitudinal direction of the plate member 1. Inside the plate member 1, the fiber direction 4a of the layered solid wood 4 extends substantially in the transverse direction of the plate member 1. It goes without saying that the fiber direction inside can also be alternated, in particular in that the central solid wood 4 again has the same fiber direction as that in the case of the large surfaces. The embodiments of FIGS. 8 to 14 were produced from plate elements according to FIGS. 1 to 7, by strips 10 separated from the starting plate elements with sections perpendicular to their large surfaces, the strips 10 folded over their longitudinal axis by 90 ° and have been connected together to form a new panel element 1. 8 to 10 show a part of a built-up of strip 10 plate member 1 ', wherein the strips 10 were separated from an output plate element 1 according to FIGS. 6 and 7. Accordingly, a strip 10 comprises sections of four layers 5 of boards 8 with grooves 9, wherein the longitudinal axes of the grooves 9 of the layers 5 are aligned alternately at opposite equal angles to the longitudinal direction of the output plate element 1. Between all of the cavity material sections 5 'of the layers 5 and on the two large surfaces of the starting plate element 1, the strips 10 comprise solid sections 4' of the layered solid wood 4. [0089] The solid sections 4 'of the large surfaces of the exit wall assigned to the strips 10 Plate element 1 of adjoining strips 10 are connected to each other via adhesive bonds. In the case of the two large surfaces of the panel element V composed of folded-down strips 10, one cover layer made of the first wooden material and thus of solid wood 4 is arranged, each with an adhesive bond. These cover layers and perpendicularly oriented webs in the form of solid strips 4 'belonging to the strips 10 enclose strip-shaped subregions with the second wood material or hollow space material sections 5'. 11 to 13 show a part of a constructed of strips 10 plate element 1 wherein the strips 10 were separated from a stack of plate elements 1 according to FIGS. 1 and 2. From the exploded view of Fig. 13 well recognizable solid wood sections 4 'and cavity material sections 5' shows that the illustrated embodiment comprises strips that of a stack with five plate elements 1 according to FIGS. 1 and 2 and between each one additional Layer of the first wood material were produced. The additional layers of the first wood material are inserted into the stack so that their fiber direction is substantially perpendicular to the fiber direction of the directly adjacent to these layers of the first wood material. Correspondingly, a strip 10 comprises five sections 5 'of layers of binder-bonded wood shavings 6 and fourteen solid wood sections 4'. In each case three directly consecutive solid wood sections 4 ', the fiber direction of the central solid wood sections 4' is aligned substantially perpendicular to the grain direction of the outer solid wood sections 4 '. The strips 10 associated solid wood sections 4 'of the large surfaces of the starting plate member 1 of adjoining strips 10 are connected to each other via adhesive bonds. In the two large surfaces of the assembled from folded strips 10 plate element 1 'is each arranged with a glued connection a cover layer of the first wood material and thus of solid wood 4. These cover layers and perpendicularly oriented webs in the form of solid strips 4 'belonging to the strips 10 enclose strip-shaped subregions with the second wood material or hollow space material sections 5'. Fig. 14 shows a part of a built-up of strips 10 plate member 1 ', wherein the strips 10 were separated from a stack of plate elements 1 according to FIGS. 1 and 2. In the illustrated embodiment, the plate elements 1 according to FIGS. 1 and 2 were made square and constructed with 90 ° alternating fiber directions of the layers of solid wood to form a stack, from which then the strips 10 were separated. By this production, solid wood sections 4 'can be achieved with changing fiber direction, without additionally introduced into the stack layers of solid wood. claims A method of manufacturing sheet elements (1, 1 ') having two large surfaces (2) and circumferential end faces (3) comprising a first wood material (4) in the form of layered solid wood having a substantially homogeneous density greater than 350 kg / m3 and a second wood material (5) is used in the form of a layer with a void fraction, wherein the average density of the layer of the second wood material (5) is less than 270 kg / m3, characterized in that layers of the first and second Wood material (4, 5) stacked together with adhesive bonds between the successive layers to a plate element (1, 1), wherein at least one layer of the second wood material (5) between two layers of the first wood material (4) is arranged, the at least one Layer of the second wood material (5) as a continuous layer in the form as it was made or provided with cavities on the gesa in the region between the respective layers of the first wood material (4) and the two large surfaces (2) are formed by layers of the first wood material (4). 2. The method according to claim 1, characterized in that the at least one layer of the second wood material (5) made of wood chips associated with binder is produced and the first wood material used (4) preferably of veneer, in particular with a thickness in the range of 0.7 to 2.5 mm, or optionally formed by a solid wood panel having a thickness in the range of 2 to 10 mm, wherein the wood chips (6) of the second wood material (5) are preferably substantially strip-shaped and flat, wavy, roll-shaped, spring-shaped or spiral and at least 80 percent by weight of the wood chips are formed by wood chips with a length in the range of 2 mm to 40 mm. 3. The method according to claim 2, characterized in that a first layer of the first wood material (4) is rolled in the form of peeled veneer from a roll on a production line, thereon provided with binder sawdust (6) in a predetermined layer thickness over the entire width a second layer of the first wood material (4) in the form of peeled veneer from a roll on top of the layer with the sawdust and pressed down with a second production belt and plate elements (1) of predetermined length from the resulting Plate material to be separated. 4. The method according to claim 2 or 3, characterized in that the binder used comprises at least a portion of an organic binder and / or an inorganic binder, wherein the organic binder is preferably a polymer binder, in particular polyvinyl acetate (PVAc), and the inorganic binder is preferably a Binder based on alkali polysilicates, in particular a mixture of sodium silicate and / or potassium silicate with lithium silicate. 5. The method according to claim 1, characterized in that the at least one layer of the second wood material (5) of a layer of on the wide surfaces with a plurality of parallel grooves (9) provided and laterally and optionally longitudinally connected boards (8) is formed, wherein the longitudinal axes of the grooves (9) parallel to the large surfaces and the first wood material (4) is a solid wood, preferably a solid wood panel with a thickness in the range of 2 to 10 mm, or optionally veneer with a thickness in the range of 0.7 to 2.5 mm. A method according to claim 5, characterized in that at least one pair of layers of boards (8) provided on the wide surfaces with a plurality of parallel grooves (9) is inserted into the plate element (1), the longitudinal axes of the grooves (9) being These two layers are aligned at opposite equal angles to the longitudinal direction of the plate element (1) and preferably the fiber direction of the first wood material (4) in the two large surfaces (2) substantially in the longitudinal direction of the plate element (1), and inside the Plate element (1) in particular substantially in the transverse direction of the plate member (1). 7. The method according to claim 5 or 6, characterized in that at least a part of the grooves (9) of the boards (8), the groove width from the broad surface away against the interior of the board (8) towards greater is formed. 8. The method according to any one of claims 1 to 7, characterized in that in a part of the void content of the second wood material (5) a heat-absorbing and / or fire-retardant aggregate is inserted. 9. The method according to any one of claims 1 to 8, characterized in that of plate elements (1) with cuts perpendicular to the large surfaces (2) strips (10) separated, the strips folded by 90 ° about its longitudinal axis and together to form a plate element (1 ') are connected, wherein the strips (10) associated portions (4') of the large surfaces (2) of adjoining strips (10) are connected to each other via adhesive bonds and in the two large surfaces (2) of the folded Strips (10) assembled plate elements (1 »), each with a glued connection a cover layer of the first wood material (4) and thus is arranged of solid wood, so that these cover layers and perpendicular thereto aligned webs in the form of belonging to the strips sections ( 4) of the layers of the first wood material (4) strip-shaped portions with the second wood material (5 ') enclose in adhesive contact. (3) produced by a process according to one of claims 1 to 9 from a first wood material (4) in the form of layered solid wood with a in the Substantially homogeneous density of more than 350 kg / m3 and a second wood material (5) in the form of a layer having a void fraction, the average density of the layer of the second wood material (5) being less than 270 kg / m3, characterized in that the plate element (1) comprises layers or portions of layers of the first and second wood materials (4, 4 ', 5, 5'), which layers are stacked together with adhesive bonds between the successive layers, where at least one Layer or a portion of the second wood material (5,5 ') between two layers or sections of the first wood material (4,4) is arranged and in the two large O. (2) cover layers in the form of layers of the first wood material (4) are arranged. Plate element (1, 1) according to claim 10, characterized in that the plate element (1, 1 ') comprises layers of the first and second wood materials (4, 5) connected by adhesive bonds, at least one layer of the second wood material (5) is arranged between two layers of the first wood material (4), the at least one layer of the second wood material (5) as a continuous layer in the form, as has been made or provided with cavities over the entire area between the respective layers of the first wood material (4) and the two large surfaces (2) of layers of the first wood material (4) are formed. 12. The plate element (1, 1 ') according to claim 10, characterized in that the plate element (1, 1') is connected by adhesive bonds to strips (10) in the form of sections of stacked layers of the first and second wood material (4 ', 5 '), wherein the strips (10) associated portions of layers of the first wood material as webs (4') are aligned perpendicular to the large surfaces (2) and extending between the cover layers and the cover layers and the webs strip-shaped portions with the second wooden material (5 ') in adhesive contact. 13. Plate element (1, 1 ') according to any one of claims 10 to 12, characterized in that the at least one layer or at least a portion of a layer of the second wood material (5') consists of wood chips (6) connected with binder and the first wood-based material used (4) is solid wood, preferably veneer, in particular with a thickness in the range of 0.7 to 2.5 mm, or optionally solid wood with a thickness in the range of 2 to 10 mm, the wood chips (6) of the second wood material (5 ) are preferably substantially strip-shaped and flat, wavy, roll-shaped, feather-shaped or spiral-shaped and at least 80 weight percent of the wood chips (6) of wood chips (6) are formed with a length in the range of 2 mm to 40 mm and in particular the binder at least one Proportion of an organic binder and / or an inorganic binder, preferably tannin, in particular polyvinyl acetate (PVAc) and / or a B based on alkali polysilicates. 14. Plate element (1, 1) according to any one of claims 10 to 12, characterized in that the at least one layer or at least a portion of a layer of the second wood material (5) of a layer or a portion of the broad surfaces formed with a plurality of parallel grooves (9) and laterally and optionally longitudinally connected boards (8) and the first wood material (4) is a solid wood, preferably a solid wood panel with a thickness in the range of 2 to 10 mm, or optionally veneer with a thickness in the range of 0.7 to 2.5 mm. 15. Use of plate elements (1, 1 ') according to any one of claims 10 to 14 as a building board, thermal insulation board, door leaf or furniture panel.