EP2397291B1 - Method and device for producing a wooden material body and wooden material body - Google Patents

Description

The invention relates to a method for producing a wood material body, is provided in the lignocellulose-containing, small-piece material, the small-sized material is mixed with a binder, one or more layers of the small-sized material are scattered and a layer structure of all scattered layers under increased pressure and elevated temperature is pressed.

Furthermore, the invention relates to an apparatus for producing a wood material body with a forming line, with one or more along the forming line arranged scatterers for spreading layers of lignocellulose-containing, small-sized material and for providing the small-piece material with binder and with a pressing device downstream of the spreaders is.

Finally, the invention relates to a wood-based material body with one or more layers of binder-containing, lignocellulose-containing, small-piece material.

Wood material body of the type described above are such as from the DE-102 38 996 known, often used in the form of so-called wood-based panels for both structural and non-bearing purposes. Non-load-bearing elements are wood-based panels For example, as a cladding of wall, ceiling or floor structures. The use in furniture and door construction is known. Wood-based panels can also be used in environments with increased humidity, but must be additionally treated to obtain a sufficient moisture resistance, in particular coated.

Wood-based panels with increased mechanical and technological properties, in particular with increased strength properties, can be used as structural components, for example as truck or container floors or as load-bearing wall elements in building construction.

However, these special wood-based material bodies or plates, which must have said increased moisture resistance and / or due to a supporting function said increased mechanical-technological properties due to the use in a humid environment, but are relatively expensive and expensive to manufacture. In addition, it may be desirable to improve the swelling properties and / or the emission behavior, which requires additional measures that complicate the manufacture accordingly.

It is therefore the object of the present invention to provide a method, a device and a wood-based material body, with which at least one of the properties mentioned, in particular the moisture resistance, the swelling behavior or the emission behavior, can be improved.

The previously derived and indicated object is achieved according to a first teaching of the present invention by the features of independent claim 1.

According to the invention, therefore, the conventional manufacturing method, in which small-sized material is provided only with a binder and then pressed, supplemented by the fact that additionally an expanding and hardening mass is added to the layer structure to be pressed. It should be noted that the said composition is added independently of the binder and in addition thereto, the composition being different from the binder. It is therefore necessary for the addition of binder which is inevitably necessary in the production of wood-based material bodies, and for the addition of the expanding and hardening, in particular flowable, composition additionally provided according to the invention. Mass to different process steps and also to different compositions.

It is also essential in the method according to the invention that the addition of the expanding and hardening mass takes place prior to the pressing of the layer structure, whereby the said mass is inevitably subjected to the increased pressure and the elevated temperature during the pressing. This makes it possible that the composition can be distributed optimally in the layer structure with a suitable composition, since at the time of application of the mass, the binder is not yet cured appreciably. As a result, the said mass can pass into cavities formed between the small-sized material during scattering, which is still supported by the increased pressure exerted on the layer structure during compression. In addition, this process is supported by the fact that the not yet cured mass can spread particularly well between the small-sized material before the bonding of the material is carried out by the binder or at least completed.

By pressing results in this way, compared to the prior art, a wood material body with particular improved moisture resistance, since after curing of the expanded mass exposed to the external environment surface of the small-sized material by filling the cavities and sheathing of the small-sized material through the Mass can be reduced to a minimum. The swelling properties and emission behavior can also be significantly improved. In particular, the emissions of VOCs (volatile organic compounds, volatile organic compounds) can be compared to the prior art reduce considerably. Finally, the mechanical-technological properties, in particular the strength properties, can be improved. It has been found that it is possible to increase the transverse tensile strength, the bending strength and / or the modulus of elasticity in a wood-based material body by the method according to the invention compared with conventionally produced wood-based material bodies without the addition of a separate expanding and hardening mass in the as yet unpressed layer structure Finally, a multi-layered construction with correspondingly many layers of the hardened mass is also advantageous in order to obtain an improved puncture resistance for container floors or the like.

According to one embodiment of the method according to the invention, the mass is applied in liquid or viscous form. In this way, the mass can be optimally distributed in the layer structure, both before pressing and during pressing. In principle, however, it is also conceivable to add the expanding and hardening mass in small-sized form, for example as granules, or in powder form.

The mass can be applied either partially or over the entire surface to the respective layer, wherein a partial application is sufficient in particular when the applied mass expands relatively strongly. A partial application may in particular be drop-shaped, thread-shaped, strip-shaped and / or planar.

According to a further embodiment of the method according to the invention, the mass expands only during the step of pressing, in particular from a certain pressing temperature. The same can also apply to the curing of the mass. In principle, it is also conceivable that the mass also expands and / or hardens after the pressing step.

In the case that the expansion and / or the curing requires a certain minimum temperature, it can be provided that the mass at a temperature of at least 60 ° C, preferably of at least 70 ° C, more preferably of at least 80 ° C, expanded and / or hardens. At lower temperatures either no reaction will start or the reaction will be delayed.

The mass is according to yet another embodiment, a plastic-containing composition, in particular a polyurethane (PU) containing mass. Expanding plastics have the advantage that in the wood-based material body according to the invention in addition to a high strength and stability, a particularly good moisture behavior is achieved, since the plastic encases the small-piece material and thereby the risk of moisture penetration is reduced in the wood material body. PU has proved to be particularly advantageous because this plastic expands relatively strong and leads to a high rigidity after curing in conjunction with a wood material. Incidentally, PU is also particularly easy to apply in liquid form. In particular, a drop-shaped order is particularly easy to implement with PU. Incidentally required PU also only relatively low reaction temperatures, which reduces the production cost of the wood material body.

According to yet another embodiment of the method according to the invention, the scattering of one or more layers of the small-sized material and / or the application of an expanding and curing, in particular flowable, mass is performed on at least one of the scattered layers in several separate sub-steps or is in several separate Sub-steps divided. The scattering of the small-sized material and / or the application of said mass can thus take place at various points of the production apparatus, in particular a forming line. In this way, said mass can be provided at different depths in the layer structure, whereby the penetration of the layer structure and the subsequent wood material body can be varied with the mass.

The scattering of one or more layers of the small-sized material and the application of an expanding and curing, in particular flowable, mass on at least one of the scattered layers is again carried out according to another embodiment in the same forming line, which greatly simplifies the production and the production time to a minimum reduced. It is also achieved in this way that the expanding and hardening mass before entry into the press, if necessary, is still so fluid that an optimal distribution within the layer structure is achieved.

According to a further embodiment of the method according to the invention, the mass is applied to one side of the respective layer, which does not form one of the outer sides of the layer structure. In particular, the mass is applied exclusively on such a side, which does not form one of the outer sides of the layer structure. In other words, a further layer of small-sized material is still scattered in the production device after the application of said mass in this case. To be particularly advantageous, a method has been found in which initially one or several layers are scattered, then said mass is applied, then again one or more further layers are scattered and then optionally the application of the mass followed by scattering one or more further layers is repeated once or several times. In principle, however, it is also conceivable that the said mass is applied to one side of the respective layer, which forms the outside of the layer structure and thus of the finished wood material body, as is guaranteed in this case that the mass before pressing and / or distributed during the compression in the layer structure at least to a certain extent.

In accordance with yet another embodiment of the method according to the invention, production parameters, meaning the parameters which materially influence the properties of the wood-based material body during production, are selected and in particular controlled such that after the crimping step the mass exceeds at least 50%, in particular at least 80%. , preferably over at least 90%, particularly preferably over 100%, of the cross section (in this context, the cross section perpendicular to Plate plane or perpendicular to the extension plane and the bottom or top of the layer structure) of at least one of the layers, in particular the entire layer structure and / or wood material body, is distributed. In other words, in this case, the mass is present in at least 50%, in particular at least 80%, preferably at least 90%, particularly preferably 100%, of the cross section of at least one of the layers, in particular of the entire layer structure and / or wood material body, and thus contributes to the cross section where it is present. In particular, for improving the strength properties, for example the transverse tensile strength, the flexural strength and / or the modulus of elasticity, it may be sufficient if the production parameters are chosen or controlled so that the mass is later distributed in the finished product only over part of the cross section. For a particularly high moisture resistance and a particularly good emission behavior, it is advantageous if the mass over 100% of the cross section of the wood material body, that is distributed over the complete cross section.

In particular, one or more of the group selected include the quantity of mass to be applied, the viscosity of the mass to be applied, the location of application of the mass, the pressing pressure during pressing, the pressing temperature during pressing and the pressing time during pressing. In principle, the composition of the expanding and hardening compound can also be controlled or varied within the layer structure as a further production parameter. For example, the composition of the mass in the interior of the layer structure can be selected so that in this area particularly high strength is achieved. In outer regions of the layer structure, the composition can be selected, for example, such that a particularly high moisture resistance or a particularly good emission behavior is achieved in these regions and in particular on the outside of the finished product.

Thus, it can also be provided that by means of the expansion and subsequent hardening of the mass a surface seal is carried out or achieved. As already indicated above, this is achieved even if the mass is not provided on the outside of the layer structure, but only in its interior.

According to a further embodiment of the method according to the invention, the blending of the small-sized material with the binder takes place before the scattering of the respective layer, so that the scattering head of a respective scattering device emits small-piece material already provided with binder. In principle, the binder can also be added during scattering and / or after scattering. It should be noted that in the context of the invention a spreader means a unit which ensures that binder-provided, small-sized material reaches the forming line. Thus, in addition to the scattering head, the scattering device can also have a device for providing the small-sized material with a binder, regardless of whether the small-sized material is provided with the binder before, during and / or after the scattering of the respective layer.

The small-piece material is provided according to yet another embodiment of the method according to the invention in the form of wood chips, wood fibers and / or wood strands (microforms according to DIN EN 300 - OSB). In the case of using wood strands instead of wood shavings or fibers, it may be provided that, during spreading, the wood strands of at least one of the layers are oriented in a predetermined direction. Also, the wooden strands of at least one other of the layers may be scattered without predetermined orientation. In this way, with the method according to the invention also an OSB board (OSB: Oriented Strands Board) can be produced. The special structure of OSB boards in connection with the method according to the invention leads to particularly good mechanical and technological properties, in particular strength properties, which is also due to the predetermined orientation of the wood strands in at least one of the layers, preferably in several layers. The production of chipboard and fiberboard, especially MDF (medium density fiberboard) or HDF (high density fiberboard) is possible.

In order to increase the strength properties still further, according to a further embodiment, an addition of fibrous reinforcing material can take place. In particular, glass, aramid and / or carbon fibers are added as a fibrous reinforcing material. The addition may take place by scattering the reinforcing material on at least one of the layers, in particular on at least one of the layers provided with said mass. Additionally or alternatively, the addition may also be done by blending the reinforcing material with the small piece material, preferably before spreading the respective situation. It is also conceivable that the addition takes place by mixing the reinforcing material with the expanding and hardening composition, preferably before the application of the composition to the respective layer.

The mass can be applied in accordance with a further embodiment of the method according to the invention in a colored form. As a result, in addition to decorative effects, it is also possible for the wood-based material bodies, in particular the wood-based panels, to be colored according to their properties and / or according to the degree of a particular property, wherein the coloration can also vary over the cross-section. By the degree of a respective property is meant, for example, the degree of moisture resistance or the degree of strength. Thus, a relatively low degree of moisture resistance, for example, with a light green colored and a relatively high moisture resistance level can be made visible with a dark green colored mass. For example, a relatively low degree of firmness can be visualized by a bright red and a relatively high degree of firmness by a dark red coloration of the mass. The method according to the invention therefore also makes it possible to identify functional properties simultaneously with the production of the wood-based material body. The coloring is therefore technically an indicator of certain properties.

It is not even necessary with the inventive method, for wood-based material body with a relatively low degree of a respective property, the mass differently, for example, weaker, to color than for Wood material body with a higher degree of the same property, since the degree of the respective property can be influenced by the degree of distribution of the mass over the cross section of the wood material body, which is inevitably also influenced by the coloring and / or intensity of the coloring. For example, in a relatively low moisture-resistant wood-based panel, the mass will be distributed only over a small portion of the cross-section and thus be visible to the outside hardly or only with a low intensity, whereas in a plate with a relatively high moisture resistance, the mass over a larger part of Cross-section, possibly even over 100% of the cross-section, will be distributed, which inevitably increases the intensity of the coloring on the outside of the plate. Incidentally, the distribution of the mass, especially when it is colored, also visible in the area of the front edges readily.

By a multi-layered structure, in which the said expanding and hardening composition is applied to several layers of small-sized material, the puncture resistance of a container floor, which is formed by the finished wood-based panel, can be increased.

The object is further achieved according to a second teaching of the present invention by a device for producing a wooden material body, in particular for carrying out the method described above, with a forming line, with one or more along the forming line arranged scattering devices for spreading layers of lignocellulose containing, kleinstückigem Material with one or more applicators for application an expanding and hardening, in particular flowable, mass on at least one of the scattered layers, wherein at least the first application device in the production movement direction at least one of the scattering devices is upstream, and with a pressing device which is downstream of the scattering and application devices.

It is understood that a spreader can also be divided into a plurality of scattering devices, each of which serves to scatter a layer of lignocellulose-containing, small-sized material. The addition of binder to the small-sized material can be done in a separate step and a separate device. But it is also conceivable that the binder addition takes place in a device which is part of the respective spreader.

With a device according to the invention, as has already been described with reference to the method, it is ensured that a wooden material body produced therewith, in particular a wood-based panel, is given an increased moisture resistance, an improved swelling behavior and / or an improved emission behavior compared with the prior art. Increased mechanical-technological properties are also feasible compared with a wood-based material body which has been produced without the use of an application device for applying said mass in front of a pressing device.

According to one embodiment of the device according to the invention a plurality of scattering devices (for scattering the small-sized material) and a plurality of application devices (for applying the expanding and curing mass) in the production movement direction are arranged one behind the other, wherein at least one application device is arranged between two scattering devices. In this way, it is ensured by simple means that in different depths of the layer structure, but not on the outside, the expanding and hardening mass can be provided, resulting in an optimum distribution of the mass within the layer structure and the later wood material body. This in turn leads to a further improvement of the mechanical and technological properties. It is understood that, as already mentioned, in another embodiment, the said mass can in principle also be provided on the outside of the layer structure.

According to yet another embodiment of the device according to the invention, this further comprises one or more means for adding fibrous reinforcing material. The ability to add such reinforcing material, the respective wood material body can be further improved in terms of its strength properties.

As already mentioned in the description of the method according to the invention, it is advantageous if production parameters for producing the wood-based material body can be varied or controlled. For this purpose, according to a further embodiment of the device according to the invention it is provided that it further comprises a control device for controlling said production parameters, wherein the control device is in particular configured so that the production parameters can be controlled so that after the step of pressing the mass over at least 50% , in particular over at least 80%, preferably over at least 90%, more preferably over 100%, of the cross section of at least one of the layers, in particular of the entire layer structure and / or wood material body, is distributed.

Finally, the object is achieved according to a third teaching of the present invention by a wood material body produced by the method described above, with one or more layers of binder-containing, lignocellulose-containing, small-sized material and with an expanded and hardened mass, wherein the mass voids between fills the provided with binder small-piece material.

Such a wood material body, which may be a plate-shaped wood material body, in particular a chip, fiber or OSB board, has, due to the expanded and cured mass, which has been distributed in the interior of the layer structure over the prior art improved moisture resistance, improved swelling properties, improved emission behavior, in particular VOC emission behavior, and / or increased mechanical-technological properties, in particular increased strength properties such as increased transverse tensile strength, increased flexural strength and / or increased modulus of elasticity. Also, by filling the voids between the small-sized material forming the plate at least partially by the hardened mass, a higher density than that of a conventional wood-based material body not produced by using such a mass can be obtained. In such a case, the apparent density may be, for example, at least 600 kg / m ³ , preferably at least 650 kg / m ³ , more preferably at least 700 kg / m ³ . Even bulk densities of more than 750 kg / m ^{3 are} conceivable. However, it is also possible to achieve lower bulk densities when selecting a suitable composition of the composition compared with conventional plates, for example by using a relatively high foaming mass. In such a case, the apparent density may be, for example, at most 600 kg / m ³ , preferably at most 550 kg / m ³ , more preferably at most 500 kg / m ³ . Even densities of less than 450 kg / m ^{3 are} conceivable. For this purpose, according to an embodiment of the wood-based material body according to the invention, it may be provided that the mass has at least 50%, in particular at least 80%, preferably at least 90%, particularly preferably more than 100%, of the cross section of at least one of the layers, in particular of the entire layer structure and / or wood material body, is distributed. Due to the degree of distribution of the mass in the finished wood material body, the aforementioned properties can be influenced individually.

In the case of the wood-based material body according to the invention, according to another embodiment, the proportion of the mass can vary over the cross-section of the wood-based material body. In particular, the proportion of the mass in the interior of the wood material body can be the highest. In principle, it is even conceivable that in the interior of the wood material body, a mass with a different composition prevails as far outside. In this way, the wood-based material body can also have an increased degree of various mechanical-technological properties, for example both an increased degree of strength and an increased moisture resistance.

Fig. 1a) und b)

Ausführungsbeispiele einer Vorrichtung zur Herstellung eines Holzwerkstoffkörpers,

Fig. 2a) bis c)

Ausführungsbeispiele eines Schichtaufbaus vor dem Verpressen, wie er in der Vorrichtung gemäß Fig. 1 erzeugt werden kann und

Fig. 3

ein Ausführungsbeispiel eines Holzwerkstoffkörpers, wie er mit der Vorrichtung gemäß Fig. 1 hergestellt werden kann.

There are now a large number of possibilities for designing and developing the method according to the invention, the device according to the invention and the wood-based material body according to the invention. For this purpose, reference is made, on the one hand, to the claims subordinate to patent claim 1, and, on the other hand, to the description of exemplary embodiments in conjunction with the drawing. In the drawing shows:

Fig. 1a) and b)

Embodiments of a device for producing a wooden material body,

Fig. 2a) to c)

Embodiments of a layer structure before pressing, as in the device according to Fig. 1 can be generated and

Fig. 3

an embodiment of a wood material body, as with the device according to Fig. 1 can be produced.

Fig. 1a ) shows by way of example a first embodiment of a device 12 for producing a wooden material body 1 with a forming line 6, with a plurality along the forming line 6 arranged scatterers 13a, 13b, 13c, 13d for spreading several layers of lignocellulose containing, small-piece material 2, wherein the scattering devices 13a, 13b, 13c, 13d can simultaneously serve to provide the small-sized material 2 with a binder. Preferably, however, the addition of binder takes place in a separate device (not shown).

The apparatus 12 further comprises a plurality of applicators 14a, 14b for applying an expanding, hardening and flowable mass 4 to some of the scattered layers. In this case, the first application device 14a based on the production movement direction P is preceded by a scattering device 13a, so that the application of the compound 4 does not take place directly on the forming line 6 or the conveyor belt (not shown), but inevitably in a region which is later in the layer structure 5 inside lies.

Furthermore, the device 12 has a pressing device 15 which is connected downstream of the scattering devices 13a, 13b, 13c, 13d and the application devices 14a, 14b.

In order to be able to provide a fibrous reinforcement 11, for example of glass, aramid and / or carbon fibers, in some layers 3b, 3c of the layer structure 5, the device 12 according to the invention also has two devices 16a, 16b for adding reinforcing material 11 in the form of fibers ,

In production movement direction P, a spreading device 13a, an application device 14a, a further spreading device 13b, a reinforcing device 16a, a further spreading device 13c, a further reinforcing device 16b, a further application device 14b and finally a last spreading device 13d follow in this exemplary embodiment.

All facilities will, as in Fig. 1a ) is represented by vertical arrows, controlled by a common control device 17, so that Production parameters of the method, which will be described below, can be set individually.

In the method according to the invention is on the spreaders 13a, 13b, 13c, 13d lignocellulose-containing, small-sized material 2, which was provided with binder, scattered in several layers 3a, 3b, 3c, 3d on the forming line 6, wherein it is the small piece Material 2 can deal with wood chips or wood fibers.

About the applicators 14a, 14b is applied as an expanding and hardening mass 4 PU in liquid form to the layers 3a and 3c drop-shaped.

Furthermore, said reinforcing fibers 11 are scattered in and on the two layers 3b and 3c via the two reinforcing devices 16a, 16b.

The layer structure 5 thus produced is then pressed in the pressing device 15 under elevated pressure and elevated temperature, wherein, as Fig. 1a ), the step of pressing takes place after the step of applying the PU compound 4.

By pressing creates a wood material body 1 in the form of an endless plate that can be subjected to further processing steps, but already has significantly increased mechanical and technological properties.

In Fig. 1a ), it can further be seen that the scattering of the small-sized material 2 is subdivided into a plurality of separate substeps, which are each performed by one of the scatterers 13a, 13b, 13c, 13d. The PU compound 4 is also applied in several substeps via the two application devices 14a, 14b.

The PU compound 4 is in the embodiment according to Fig. 1a ) applied exclusively on one side of the respective layer 3a, 3c, which does not form one of the outer sides 8 of the layer structure.

As mentioned, production parameters can be controlled via the control device 17. Thus, the amount, the viscosity and the place of application of the PU mass 4 and the pressing pressure, the pressing temperature and the pressing time in the pressing device 15 can be controlled individually. The control device 17 thus enables the PU compound 4 to be distributed over up to 100% of the cross section of the entire wooden material body 1 after the crimping step, which is shown schematically in the wood material body 1 on the right side of FIG Fig. 1a ) is shown. In this case, the proportion of PU mass 4 decreases from the center of the wood material body 1 to the outside.

In this way, by means of the expansion and subsequent hardening of the PU compound 4, a surface sealing of the wood-based material body 1 has been achieved.

Another embodiment of a device 12 for producing a wooden material body 1 shows Fig. 1b ). Here the PU compound 4 is always provided between respectively adjacent layers 3a and 3b or 3b and 3c or 3c and 3d. Reinforcing fibers 11 are scattered prior to scattering the penultimate layer 3c on the PU mass 4, which has been applied to the underlying layer 3b. In this case, the reinforcing fibers 11 can be distributed during the production of the corresponding wood material body 1 in the layer structure 5, on the one hand due to the scattering of the layer 3c, which can lead to a mixing, on the other hand by the expansion of the PU mass 4, the between the layers 3b and 3c has been applied and the reinforcing fibers 11 can at least partially transport through the layer structure 5.

The apparatus 12 comprises a spreader 13a for this purpose, followed by an applicator 14a, followed by another spreader 13b, again followed by an applicator 14b, followed by an armor 16a, followed by yet another spreader 13c, again followed by an applicator 14c , finally followed by a last spreader 13d.

In the FIGS. 2a ) to c) are shown some embodiments of a layer structure 5, as it can be achieved with the device 12 described above and pressed.

According to Fig. 2a ) are provided two layers 3a, 3b of scattered wood fibers 10 in the layer structure 5, wherein on the lower layer 3a an expanding and hardening plastic compound 4 of PU before scattering the upper layer 3b has been applied. Such a layer structure 5 results after pressing in the pressing device 15 a fiberboard with increased mechanical and technological properties.

The FIGS. 2b ) and c) each show a layer structure 5, which results after pressing an OSB board.

According to Fig. 2b ) two layers 3a, 3b were scattered from each oriented in different directions wood strands 9 (according to DIN EN 300 - OSB), wherein between the layers 3a, 3b also a plastic compound 4 is provided. In addition, fibrous reinforcing material 11 was integrated into the two layers 3a, 3b. Alternatively or additionally, it is also conceivable not to integrate the fibrous reinforcing material 11 into the layers 3a, 3b by mixing or sprinkling it with the small-sized material 2, but rather by mixing the reinforcing material 11 with the latter before applying the mass 4. Also, the reinforcing material 11 can be sprinkled onto the mass 4. It is understood that in a layer structure 5 (not shown) comprising more than two layers 3a, 3b, etc., the reinforcing material 11 need not be provided between all the individual layers 3a, 3b, etc., but also only between two adjacent layers, in particular between the layers two middle layers, can be provided.

According to Fig. 2c ), the layer structure 5 on three layers 3a, 3b, 3c of scattered with different orientation wood strands 9, wherein between each adjacent layers in each case an expanding and hardening plastic mass 4 has been applied.

Fig. 3 Finally, shows an embodiment of a wood material body 1, as with the in Fig. 1a ) or b) illustrated device 12 and for example from the in Fig. 2a ) layer structure 5 can be produced.

It can be clearly seen that the expanded and cured mass 4 is distributed over the entire cross section of the wood-based material body 1, that is, extends into the peripheral regions. The proportion of plastic or PU mass 4 in the middle of the wood material body 1 is relatively high and decreases towards the outside. Such a plate-shaped wooden material body 1 is thus simultaneously surface-sealed by the expanded and subsequently cured mass 4. According to the invention, after the production of a layer structure 5 and after the compression of this layer structure 5, no further processing step, in particular no coating, is necessary in order to achieve increased mechanical-technological properties, in particular increased moisture resistance and / or increased strength properties.

Claims (16)

1. A method for producing a wood based material body (1), in which the following steps are executed:

   - Preparation of a fragmentary material (2) containing lignocellulose,

   - Mixing of the fragmentary material (2) with a binding agent,

   - Spreading of one or a plurality of layers (3a, 3b, 3c, 3d) of the fragmentary material (2), mixed with the binding agent, onto the forming line (6),

   - Application of an expanding and hardening mass (4) onto at least one of the spread layers (3a, 3b, 3c, 3d) of fragmentary material (2) mixed with the binding agent, and

   - Pressing a layered structure (5) of all spread layers (3a, 3b, 3c, 3d) at an elevated pressure and elevated temperature, wherein the step of pressing takes place after the step of application of the mass (4),

   - wherein the mass (4) expands only during and/or after the step of pressing.
2. The method in accordance with claim 1, characterised in that the mass (4) is applied in a liquid or viscous form either partially, in particular in the form of drops, threads, strips, and/or in areas, or over the whole area.
3. The method in accordance with one of the preceding claims, characterised in that the mass (4) expands and/or hardens only during and/or after the step of pressing, in particular at a temperature of at least 60°C, preferably of at least 70°C, particularly preferably of at least 80°C.
4. The method in accordance with one of the preceding claims, characterised in that the mass (4) is a mass (4) containing plastic, in particular a mass (4) containing polyurethane.
5. The method in accordance with one of the preceding claims, characterised in that the mass (4) is applied, in particular exclusively, on one side (7) of the layer (3a, 3b, 3c, 3d) in question, which does not form one of the external faces (8) of the layered structure (5).
6. The method in accordance with one of the preceding claims, characterised in that production parameters are selected such that after the step of pressing the mass (4) is distributed over at least 50%, in particular over at least 80%, preferably over at least 90%, particularly preferably over 100%, of the cross section of at least one of the layers (3a, 3b, 3c, 3d), in particular of the whole layered structure (5) and/or wood based material body (1), wherein as production parameters in particular one or a plurality are selected from the group comprising the quantity of mass (4) to be applied, the viscosity of the mass (4) to be applied, the area at which the mass (4) is applied, the pressure applied during pressing, the temperature during pressing, and the duration of pressing.
7. The method in accordance with claim 6, characterised in that by means of the expansion and subsequent hardening of the mass (4), sealing of the surface is effected.
8. The method in accordance with one of the preceding claims, characterised in that an addition of fibrous reinforcement material (11) takes place, wherein in particular glass, aramide and/or carbon fibres are added as the fibrous reinforcement material (11).
9. The method in accordance with one of the preceding claims, characterised in that the mass (4) is applied in a coloured form.
10. A device (12) for producing a wood based material body (1), in particular for purposes of executing the method in accordance with one of the preceding claims,

    - with a forming line (6),

    - with one or a plurality of spreading devices (13a, 13b, 13c, 13d) arranged along the forming line (6) for purposes of spreading layers (3a, 3b, 3c, 3d) of fragmentary material (2) containing lignocellulose,

    - with a device for the addition of a binding agent,

    - with one or a plurality of application devices (14a, 14b), separate from the device for the addition of binding agent, for purposes of applying an expanding and hardening mass (4) onto at least one of the spread layers (3a, 3b, 3c, 3d), wherein at least one of the spreading devices (13a, 13b, 13c, 13d) is installed upstream of at least the in the direction of production movement (P) first application device (14a), and

    - with a pressing device (15), which is installed downstream of the spreading and application devices (13a, 13b, 13c, 13d, 14a, 14b).
11. The device (12) in accordance with claim 10, characterised in that a plurality of spreading devices (13a, 13b, 13c, 13d) and a plurality of application devices (14a, 14b) are arranged one behind another in the direction of production movement (P), wherein at least one application device (14a, 14b) is arranged between two spreading devices (13a, 13b, 13c, 13d).
12. The device (12) in accordance with claim 10 or 11, characterised in that the device (12) furthermore has a control device (17) for purposes of controlling production parameters, which is configured such that the production parameters can be controlled such that after the step of pressing the mass (4) is distributed over at least 50%, in particular over at least 80%, preferably over at least 90%, particularly preferably over 100%, of the cross-section of at least one of the layers (3a, 3b, 3c, 3d), in particular of the whole layered structure (5) and/or wood based material body (1).
13. A wood based material body (1) produced by the method in accordance with one of the claims 1 to 9,

    - with one or a plurality of layers (3a, 3b, 3c, 3d) of the fragmentary material (2) containing lignocellulose and provided with binding agent, and

    - with an expanded and hardened mass (4), wherein the mass (4) fills cavities (18) between the fragmentary material (2) provided with binding agent.
14. The wood based material body (1) in accordance with claim 13, characterised in that the mass (4) is distributed over at least 50%, in particular over at least 80%, preferably over at least 90%, particularly preferably over 100%, of the cross section of at least one of the layers (3a, 3b, 3c, 3d), in particular of the whole layered structure (5) and/or wood based material body (1).
15. The wood based material body (1) in accordance with claim 13 or 14, characterised in that the proportion of mass (4) varies over the cross section of the wood material body (1), and in particular is a maximum in the interior of the wood based material body (1).
16. The wood based material body (1) in accordance with one of the claims 13 to 15, characterised in that the wood material body (1) is a wood based material body (1) in board form, in particular a chipboard, fibreboard, or OSB board.

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