EP4010158B1 - Material board and method for producing a material board - Google Patents

Material board and method for producing a material board Download PDF

Info

Publication number
EP4010158B1
EP4010158B1 EP20753340.7A EP20753340A EP4010158B1 EP 4010158 B1 EP4010158 B1 EP 4010158B1 EP 20753340 A EP20753340 A EP 20753340A EP 4010158 B1 EP4010158 B1 EP 4010158B1
Authority
EP
European Patent Office
Prior art keywords
cover
layer
layers
strands
chips
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP20753340.7A
Other languages
German (de)
French (fr)
Other versions
EP4010158A1 (en
EP4010158C0 (en
Inventor
Michael SCHÖLER
Jörg Heinz Hüneke
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siempelkamp Maschinen und Anlagenbau GmbH and Co KG
Original Assignee
Siempelkamp Maschinen und Anlagenbau GmbH and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siempelkamp Maschinen und Anlagenbau GmbH and Co KG filed Critical Siempelkamp Maschinen und Anlagenbau GmbH and Co KG
Publication of EP4010158A1 publication Critical patent/EP4010158A1/en
Application granted granted Critical
Publication of EP4010158B1 publication Critical patent/EP4010158B1/en
Publication of EP4010158C0 publication Critical patent/EP4010158C0/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B27WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27NMANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
    • B27N3/00Manufacture of substantially flat articles, e.g. boards, from particles or fibres
    • B27N3/08Moulding or pressing
    • B27N3/10Moulding of mats
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B27WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27NMANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
    • B27N7/00After-treatment, e.g. reducing swelling or shrinkage, surfacing; Protecting the edges of boards against access of humidity
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B27WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27NMANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
    • B27N3/00Manufacture of substantially flat articles, e.g. boards, from particles or fibres
    • B27N3/02Manufacture of substantially flat articles, e.g. boards, from particles or fibres from particles
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B27WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27NMANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
    • B27N3/00Manufacture of substantially flat articles, e.g. boards, from particles or fibres
    • B27N3/04Manufacture of substantially flat articles, e.g. boards, from particles or fibres from fibres
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B27WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27NMANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
    • B27N3/00Manufacture of substantially flat articles, e.g. boards, from particles or fibres
    • B27N3/08Moulding or pressing
    • B27N3/10Moulding of mats
    • B27N3/14Distributing or orienting the particles or fibres
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B27WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27NMANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
    • B27N3/00Manufacture of substantially flat articles, e.g. boards, from particles or fibres
    • B27N3/08Moulding or pressing
    • B27N3/10Moulding of mats
    • B27N3/14Distributing or orienting the particles or fibres
    • B27N3/143Orienting the particles or fibres
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B27WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27NMANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
    • B27N3/00Manufacture of substantially flat articles, e.g. boards, from particles or fibres
    • B27N3/08Moulding or pressing
    • B27N3/18Auxiliary operations, e.g. preheating, humidifying, cutting-off
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B27WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27NMANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
    • B27N3/00Manufacture of substantially flat articles, e.g. boards, from particles or fibres
    • B27N3/08Moulding or pressing
    • B27N3/28Moulding or pressing characterised by using extrusion presses
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B27WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27NMANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
    • B27N7/00After-treatment, e.g. reducing swelling or shrinkage, surfacing; Protecting the edges of boards against access of humidity
    • B27N7/005Coating boards, e.g. with a finishing or decorating layer

Definitions

  • the invention relates to a material board, in particular a wood-based material board, with at least one (inner) core layer (or middle layer) made of strands and with (outer) cover layers or outer layers made of chips.
  • the (wood) material board is produced from a pressed material mat, which contains the strands for the core layer on the one hand and the chips for the cover layers on the other hand, using pressure and heat by pressing (in a hot press).
  • the invention also relates to a method for producing a material board, in particular a wood-based material board.
  • fiberboards e.g. MDF boards
  • chipboards which are made from wood chips
  • OSB boards oriented strand board
  • multilayer wood-based panels are known from the state of the art, which as hybrid panels consist of different wood-based particles, e.g. both strands and chips.
  • Strands in the context of the invention means the strands generally used for OSB boards, which are also referred to as coarse chips or narrow-long chips and which have an (average) length of more than 50 mm, preferably more than 80 mm, e.g. 100 mm to 200 mm.
  • the (average) width is more than 5 mm, preferably more than 8 mm, e.g. 10 mm to 50 mm.
  • the (average) thickness is more than 0.5 mm, e.g. 0.6 mm to 1.5 mm.
  • the core layer is made from such strands.
  • the cover layers i.e. the upper cover layer and the lower cover layer
  • the cover layers are made of (classic) chips, which have significantly smaller dimensions than the strands. They have an (average) length of less than 20 mm, preferably less than 10 mm and/or an (average) width and thickness of less than 1 mm.
  • Such chips which are also referred to as fine chips, are usually used for the production of classic chipboards.
  • OSB boards made from strands are characterized by a higher bending strength than normal chipboards, which are also known as flat-pressed boards, due to the use of long and slender strands.
  • the disadvantage of OSB boards is usually the rough surface caused by the coarse particles, which is particularly disadvantageous for subsequent surface treatment, e.g. painting, as the coarse structure remains visible through the coating or paint application.
  • multilayer hybrid panels of the type described above have cover layers on both sides that do not consist of (coarse) strands, but of (fine) chips (or alternatively of fibers), so that wood-based panels with excellent optical properties are created.
  • the disadvantage of these wood-based panels is that the strands responsible for the bending strength are relatively far from the surface, thereby reducing the bending strength compared to conventional OSB boards.
  • a multilayer wood-based panel and a method for producing such a panel, which contains one or more core layers of strands and one or more cover layers of finer particles, is known, for example, from US 6 461 743 B1
  • papers are processed there to improve the properties of the plate.
  • the core layer can be made from veneers that are arranged in a known manner in several layers on top of each other with the fibers crossing essentially at right angles.
  • a wood-based panel in particular OSB panel with aligned narrow-long wood chips, is also from the DE 199 13 589 A1
  • the panel is made up of a sandwich construction consisting of a middle layer and cover layers on both sides, whereby the two cover layers are designed as at least double layers with an outer layer and an inner layer, each with wood chips oriented in different directions.
  • an OSB board with at least one upper cover layer, at least one middle layer and at least one lower cover layer, all of which consist of resin-bonded strands.
  • a fabric layer is applied to the surface of the upper cover layer or the lower cover layer to increase the bending strength.
  • a device and a method for producing a multi-layer grit mat for pressing in a press during the production of material panels are described, whereby coarse chips are scattered in an oriented manner to form a layer using a first scattering head and fine chips are scattered in an oriented, classified and/or unoriented manner as a further layer onto the coarse chips using a second scattering head.
  • the pre-pressing of layers before the upper covering layer is scattered is intended to prevent very long coarse chips/chips in the grit for producing the middle layer from piercing through the covering layers to the surface during pressing in a main press.
  • Another method for producing an OSB board is in the EP 3 811 314 A1 described.
  • the object of the invention is to create a material plate of the type described at the outset, which is characterized by both high flexural rigidity and a perfect surface finish while being simple in construction and economical in production.
  • the invention teaches a material plate with the features of claim 1 and a method with the features of claim 7. It is provided that one or preferably both cover layers are designed as non-full-surface cover layers in such a way that individual strands extend at least partially through the respective cover layer to the plate surface, forming interruptions in the cover layer, and are thus visible.
  • the invention is based on the knowledge that panels, e.g. wood-based panels with particularly high flexural rigidity or flexural strength can be produced on an OSB basis and therefore from strands, preferably from several layers of strands with different orientations.
  • the invention is also based on the knowledge that, in order to improve the surface properties, it is fundamentally advantageous to provide such an OSB core layer or such OSB core layers on both sides with cover layers made of chips and in particular fine chips.
  • the invention has recognized that, in order to improve the surface properties, it is not necessary to produce the cover layers from fine material in such a thick layer that the cover layers completely cover the OSB core layers.
  • the core layer or on the core layers to fill and level the gaps between the individual coarse chips.
  • a particularly advantageous feature is the fact that the flexural rigidity of the wood-based panel, which is essentially ensured by the OSB core layer, is only slightly impaired because the cover layers made of fine material are extremely thin and do not cover the entire surface.
  • a wood-based panel is created that is easy and inexpensive to manufacture and yet has both excellent strength properties and a good surface quality. This makes the panel particularly suitable for further processing, for example by coating or applying paint.
  • plant particles and therefore lignocellulose-containing particles are used as particles for both the core layer and the cover layer, in particular from perennial plants (wood).
  • Strands made of wood or wood materials are particularly preferably used for the core layer.
  • annual plants e.g. grass-like plants, straw or the like
  • the chips for the cover layers are also plant particles, i.e. lignocellulose-containing particles.
  • chips made from perennial plants wood chips
  • chips with the specified dimensions made from annual plants can also be used, e.g. from grass-like plants, straw or the like.
  • the board it is preferable not to use just a single or homogeneous core layer made of strands, but to use several core layers made of Strands or a core layer made up of several layers, the strands of which are oriented in different directions.
  • three layers can be provided in the core layer, e.g. a middle layer and two outer layers, with the cover layers made of chipboard bordering the two outer layers of the core layer.
  • the strands in the middle layer of the core layer are preferably oriented transversely to the longitudinal direction of the panel and thus transversely to the transport direction of the mat or panel during the manufacturing process.
  • the two outer layers of the core layer are preferably oriented longitudinally and thus along the longitudinal direction of the panel or the transport direction.
  • the core layer (or the plurality of core layers) may preferably (together) have a basis weight of more than 5 kg/m 2 , e.g. a basis weight of 5 to 15 kg/m 2 .
  • covering layers made of chips with a weight per unit area of less than 1.5 kg/m 2 , preferably less than 1 kg/m 2 .
  • the two cover layers (made of chips or fine chips) have a different weight per unit area, whereby the weight per unit area of one cover layer, e.g. the upper cover layer, is preferably at least 10% greater than the weight per unit area of the other cover layer, e.g. the lower cover layer, particularly preferably at least 15% greater.
  • the invention is based on the knowledge that in the course of production, a multi-layered mat of pressed material is first produced, which is then pressed in a press using pressure and heat.
  • a Belt conveyors in a forming station or forming line first spread the covering layer material for the lower covering layer, then spread the one core layer or several core layers made of strands on top of that, and then spread the upper covering layer or the material for the upper covering layer (chips or fine chips) on this core layer or the upper core layer. While the material for the lower covering layer lies flat on the belt conveyor, the material for the upper covering layer can trickle into the previously spread core layer and consequently into the area between the strands, so that in order to achieve optimal panel properties, slightly more material is used for the upper covering layer or the upper pressed material layer than for the lower covering layer.
  • the invention therefore relates not only to the material board or wood-based material board, but also to a method for producing a material board or wood-based material board, whereby a multi-layered pressed material mat is produced with at least one (middle) core pressed material layer made of strands (or coarse chips) and a lower and an upper cover pressed material layer made of chips (or fine chips), and whereby the multi-layered pressed material mat is pressed to form the (wood) material board with middle layer and cover layers.
  • the mat can be pressed in a known manner in a continuously operating press (e.g. double belt press) or alternatively in a cycle press.
  • the surfaces of the cover layers can be sanded down after pressing.
  • the cover layers are designed as non-full-surface cover layers in such a way that individual strands extend at least partially through the cover layer to the board surface, forming interruptions in the cover layer, and are thus visible.
  • the beaches therefore extend partially but only partially over the entire thickness of the plate, i.e. in some places on the plate strands are arranged across the entire thickness.
  • the lower and upper cover pressed material layers are first produced in such a way that, during the pressing process, full-surface cover layers with a closed surface are created from cover layer chips and that the non-full-surface cover layers are then created by surface processing, e.g. by sanding the cover layers, and individual strands extend at least partially through the cover layers to the board surface, forming breaks in the cover layers, and thus become visible.
  • wood-based panels with completely closed chip surfaces are therefore initially created in an intermediate step, which are then (immediately) "opened” by machining, e.g. a sanding process, so that the wood-based panel according to the invention is available after this additional process step.
  • the core pressed material layer i.e. the OSB layer or layers
  • the core pressed material layer in a generally known manner from scatterable or free-flowing strands by means of a scattering process, preferably from strands that are mixed with a conventional binding agent.
  • generally known scattering machines or scattering machine arrangements with one or more scattering heads can be used, so that one or more core pressed material layers (or layers) can be produced from strands with the desired orientation in a generally known manner.
  • the cover pressed material layers can also be produced from free-flowing and therefore scatterable chips by means of a scattering process.
  • chips mixed with a binding agent are used.
  • known spreading machines can also be used, so that in one possible embodiment, the material for the lower cover layer is first spread on the spreading belt, then the strands for the core layer or core layers and finally the material for the upper cover layer, so that a multi-layer mat of pressed material is then introduced into a press and pressed using pressure and heat.
  • the cover layers are not produced in the classic way from free-flowing material through a scattering process, but from a flowable, pasty and possibly viscous chip-liquid mixture.
  • the cover layers can be applied particularly thinly and thus particularly economically.
  • the pasty layer can flow and thus perfectly fill the gaps between the OSB chips and level the surfaces.
  • the cover pressed material layers are produced from the flowable chip-liquid mixture in the manner of a suspension, which on the one hand contains solid particles (chips) and on the other hand a liquid, e.g.
  • a flowable mixture is used, i.e. the mixture of chips and the liquid (especially water, but also glue and washing emulsion as well as other liquid additives) is adjusted so that the resulting viscosity of the mixture remains flowable.
  • the proportion of liquid in the mixture is more than 100% of the Proportion of (dry) chips, based on weight, particularly preferably more than 200%. This means that within the mixture the liquid portion is at least as large as the chip portion, preferably at least twice (i.e. 200%), particularly preferably at least three times (i.e. 300%), in each case based on weight.
  • the flowable liquid-chip mixture can be produced in various ways. For example, it is possible to produce a liquid-glue mixture and, on the other hand, to reduce the wood particles to the desired size in a mill in the usual way and then to mix the wood particles with the liquid-glue mixture, e.g. in a separate mixer.
  • a liquid-glue mixture can be added to the wood particles in the mill and thus in the crushing process, so that mixing with the liquid takes place in the mill.
  • the liquid, the glue and the wood particles can each be added separately to the mill, so that the three components are mixed in the mill to form the liquid-wood mixture.
  • the flowable mixture or slurry produced in this way can be processed into web-like layers using various methods, e.g. by extrusion.
  • the lower layer can be extruded onto the conveyor.
  • the OSB layer is then spread on top of this in the usual way and the upper covering layer or the material for the upper covering layer is then extruded onto this.
  • it can also be applied using a roller.
  • strands mean long, narrow chips with a length of more than 50 mm, preferably more than 80 mm, e.g. 100 mm to 200 mm and with an average width of more than 5 mm, preferably more than 8 mm, e.g. 10 mm to 50 mm and with a thickness of more than 0.5 mm, e.g. 0.6 mm to 1.5 mm.
  • chips for the cover layers are understood to mean conventional chips that are significantly smaller than the strands of the core layer.
  • Chips means wood particles with a length of less than 20 mm, preferably less than 10 mm, and with an average width and an average thickness of less than 2 mm, preferably less than 1 mm. It is particularly preferred to use fine chips or fine chips with a size (in the dry state) that corresponds to a sieve passage of less than 2 mm, preferably less than 1 mm, particularly preferably less than 0.5 mm for the cover layers.
  • Strands and chips used according to the invention are produced by (mechanical) comminution of the starting product (e.g. wood) and are to be distinguished from the also known fibers (e.g. for MDF), which are not used according to the invention.
  • the starting product e.g. wood
  • MDF also known fibers
  • Particles (strands and chips) mixed with a binding agent are always preferred.
  • binding agents for the production of wood-based panels can be used.
  • isocyanates or isocyanate-based binding agents (pMDI) can be used as binding agents.
  • a urea resin or a binder based on urea resin can be used.
  • Phenolic glues (PF) or melamine-reinforced UF (MUF) can also be used. These can optionally be provided with phenol (MUPF, UMPF).
  • a wood-based panel 1 according to the invention is shown in a simplified vertical section, which has on the one hand a core layer 2 made of strands 3 and on the other hand an upper cover layer 4 and a lower cover layer 5 made of chips 6.
  • the core layer 2 consists of several layers 2a, 2b, 2c, each of which consists of strands 3, the strands 3 being oriented in the individual layers 2a, 2b, 2c.
  • the figures show a possible embodiment in which the strands 3 in the middle layer 2b are transverse to the longitudinal direction of the panel or production direction P.
  • the strands 3 of the upper layer 2a and the lower layer 2c are longitudinally oriented, i.e.
  • an upper cover layer 4 made of (fine) chips 6 is provided in the board according to the invention, this is designed so thinly according to the invention that individual strands 3 protrude to the surface and consequently through the cover layers 4, 5 and are thus visible. Consequently, only very small amounts of cover layer chips 6 are used and these serve (only) to level or even out the relatively coarse surfaces of the OSB board, so that a wood-based panel 1 with perfect surface quality is provided.
  • Fig. 2 Please note that in most cases only parts of Strands 3 can be seen in this illustration, as these strands are partly below the surface and only their ends or sections protrude to the surface and are visible from the surface.
  • Such a wood-based panel is manufactured according to Figures 1 and 2 by first producing a multi-layered pressed material mat 1', which comprises a core pressed material layer 1' made of strands and an upper cover pressed material layer 4' of chips and a lower cover pressed material layer 5' of chips 6.
  • Such a pressed material mat 1' which is produced on a forming belt 7, is in Fig.3
  • This pressed material mat 1' can be pressed, for example, in a press 8 using pressure and heat to form the wood-based panel according to Fig.1
  • the figures show an embodiment in which the layers are produced in a manner not according to the invention during the manufacture of the pressed material mat 1' in such a way that during the pressing in the press 8 the wood-based panel 1 is produced directly, in which the strands of the core layer 2 extend through the cover layers 4, 5 to the surface and thus become visible.
  • a pressed material mat 1' is shown in which all layers are produced from scatterable, free-flowing pressed material, i.e.
  • both the cover pressed material layers 4', 5' and the core pressed material layer 2' are produced or scattered one after the other on the forming belt 7 from chips or strands in free-flowing form using conventional scattering devices.
  • these are particles 3, 6 which are provided with a binding agent.
  • the core layer 2 consists of several layers 2a, 2b, 2c with different strand orientations.
  • a pressed material mat 1' is produced, in which the core pressed material layer 2' is again produced from several layers 2a ⁇ , 2b', 2c' with the corresponding orientations of the strands 3.
  • This is also in Fig.3 indicated by the different representation of the strands 6 in the individual layers 2a ⁇ , 2b ⁇ , 2c'.
  • Fig.3 indicated that slightly less chips 6 are used for the lower cover pressed material layer 5' than for the upper cover pressed material layer 4'.
  • the background to this is the consideration that the lower cover pressed material layer 5' is initially applied essentially closed and flat to the forming belt 7, while the upper cover pressed material layer 4' applied to the core layer 2' partially trickles into the surface.
  • unequal tensile stresses are formed in the cover layers after pressing. Due to the unequal surface weights of the two fine chip cover layers, this is balanced out in the pressing process, so that a wood-based panel 1 with perfect properties is produced.
  • the cover pressed material layers 4 ⁇ , 5' not from conventional free-flowing chips, but from a flowable chip-liquid mixture 9.
  • An example of such production is Fig.4 shown.
  • the system for producing a material board 1, which is only shown in simplified form, has the already mentioned press 8 and the forming belt 7, on which the pressed material mat 1' is produced, so that this pressed material mat 1' is pressed in the press 8 using pressure and heat to form the wood-based panel 1.
  • the system has a forming station 10, which on the one hand has application devices 11 for the core layer and on the other hand application devices 12 for the cover layers.
  • the application devices 11 for the core layer are designed as conventional spreading machines or spreading heads for applying the strands 3
  • the application devices 12 for the two cover layers in this exemplary embodiment are designed for the already mentioned liquid application of the cover layers or for producing the chip-liquid mixture 9. It can e.g. B. extrusion devices with which the chip-liquid mixture 9 is applied to form the respective cover layer 4 ⁇ , 5'.
  • the forming belt 7 is the lower cover pressed material layer 5' is applied as a chip-liquid mixture.
  • the individual layers 2a, 2b, 2c of the core pressed material layer 2' are then sprinkled on in the conventional manner, using the application devices 11, with a spreading head 11 for the lower core layer and a spreading head 11 for the upper core layer and two spreading heads 11 for the middle core layer in between being indicated.
  • the upper cover pressed material layer 4' is then applied as a chip-liquid mixture to the sprinkled core pressed material layer 2', using an application device 12 designed as an extrusion device.
  • Fig.4 The merely indicated system will of course have other, usual components that are Fig.4 are not shown.
  • devices for processing the mat 1' to be pressed there can be arranged devices for processing the mat 1' to be pressed, a pre-press and/or pre-heating device, devices for detecting foreign bodies and/or a misfill device.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Wood Science & Technology (AREA)
  • Forests & Forestry (AREA)
  • Dry Formation Of Fiberboard And The Like (AREA)

Description

Die Erfindung betrifft eine Werkstoffplatte, insbesondere Holzwerkstoffplatte, mit zumindest einer (inneren) Kernschicht (bzw. Mittelschicht) aus Strands und mit (äußeren) Deckschichten bzw. Außenschichten aus Spänen. Die (Holz)Werkstoffplatte wird aus einer Pressgutmatte, welche einerseits die Strands für die Kernschicht und andererseits die Späne für die Deckschichten enthält, unter Anwendung von Druck und Wärme durch Pressen (in einer Heißpresse) hergestellt. Außerdem betrifft die Erfindung ein Verfahren zur Herstellung einer Werkstoffplatte, insbesondere Holzwerkstoffplatte.The invention relates to a material board, in particular a wood-based material board, with at least one (inner) core layer (or middle layer) made of strands and with (outer) cover layers or outer layers made of chips. The (wood) material board is produced from a pressed material mat, which contains the strands for the core layer on the one hand and the chips for the cover layers on the other hand, using pressure and heat by pressing (in a hot press). The invention also relates to a method for producing a material board, in particular a wood-based material board.

Bei Holzwerkstoffplatten unterscheidet man im Stand der Technik in der Regel zwischen Faserplatten (z. B. MDF-Platten), die aus Holzfasern hergestellt werden und Spanplatten, die aus Holzspänen hergestellt werden, sowie OSB-Platten (Oriented Strand Board), die aus ausgerichteten bzw. orientierten Strands hergestellt werden. Stets erfolgt das Pressen der Partikel unter Anwendung von geeigneten Bindemitteln, wobei in der Regel die Partikel unmittelbar als beleimte bzw. mit einem Bindemittel versehene Partikel zur Verfügung gestellt und zu der jeweiligen Matte gestreut werden, die anschließend in der Presse unter Anwendung von Druck und Wärme verpresst wird.In the case of wood-based panels, the state of the art generally distinguishes between fiberboards (e.g. MDF boards), which are made from wood fibers, and chipboards, which are made from wood chips, as well as OSB boards (oriented strand board), which are made from aligned or oriented strands. The particles are always pressed using suitable binding agents, whereby the particles are usually made available directly as glued or bonded particles and scattered to form the respective mat, which is then pressed in the press using pressure and heat.

Ferner sind aus dem Stand der Technik mehrschichtige Holzwerkstoffplatten bekannt, die als Hybridplatten aus unterschiedlichen Holzwerkstoffpartikeln bestehen, z. B. sowohl aus Strands als auch aus Spänen.Furthermore, multilayer wood-based panels are known from the state of the art, which as hybrid panels consist of different wood-based particles, e.g. both strands and chips.

Strands meint im Rahmen der Erfindung die grundsätzlich für OSB-Platten eingesetzten Strands, die auch als Grobspäne oder Schmal-Lang-Späne bezeichnet werden und die eine (mittlere) Länge von mehr als 50 mm, vorzugsweise mehr als 80 mm, z. B. 100 mm bis 200 mm aufweisen. Die (mittlere) Breite beträgt mehr als 5 mm, vorzugsweise mehr als 8 mm, z. B. 10 mm bis 50 mm. Die (mittlere) Dicke beträgt mehr als 0,5 mm, z. B. 0,6 mm bis 1,5 mm. Im Rahmen der Erfindung ist die Kernschicht aus solchen Strands hergestellt.Strands in the context of the invention means the strands generally used for OSB boards, which are also referred to as coarse chips or narrow-long chips and which have an (average) length of more than 50 mm, preferably more than 80 mm, e.g. 100 mm to 200 mm. The (average) width is more than 5 mm, preferably more than 8 mm, e.g. 10 mm to 50 mm. The (average) thickness is more than 0.5 mm, e.g. 0.6 mm to 1.5 mm. In the context of the invention, the core layer is made from such strands.

Demgegenüber sind die Deckschichten, das heißt die obere Deckschicht und die untere Deckschicht aus (klassischen) Spänen hergestellt, die deutlich geringere Abmessungen als die Strands aufweisen. Sie weisen eine (mittlere) Länge von weniger als 20 mm, vorzugsweise weniger als 10 mm und/oder eine (mittlere) Breite und Dicke von weniger als 1 mm auf. Solche Späne, die auch als Feinspäne bezeichnet werden, werden üblicherweise für die Herstellung klassischer Spanplatten eingesetzt.In contrast, the cover layers, i.e. the upper cover layer and the lower cover layer, are made of (classic) chips, which have significantly smaller dimensions than the strands. They have an (average) length of less than 20 mm, preferably less than 10 mm and/or an (average) width and thickness of less than 1 mm. Such chips, which are also referred to as fine chips, are usually used for the production of classic chipboards.

Die aus Strands hergestellten OSB-Platten zeichnen sich durch den Einsatz der langen und schlanken Strands durch eine höhere Biegefestigkeit aus als die normalen Spanplatten, die auch als Flachpressplatten bezeichnet werden. Nachteilig bei OSB-Platten ist jedoch in der Regel die durch die groben Partikel bedingte raue Oberfläche, die insbesondere für eine anschließende Oberflächenbearbeitung, z. B. einen Farbauftrag nachteilig ist, da die grobe Struktur durch die Beschichtung oder den Farbauftrag hindurch sichtbar bleibt.The OSB boards made from strands are characterized by a higher bending strength than normal chipboards, which are also known as flat-pressed boards, due to the use of long and slender strands. However, the disadvantage of OSB boards is usually the rough surface caused by the coarse particles, which is particularly disadvantageous for subsequent surface treatment, e.g. painting, as the coarse structure remains visible through the coating or paint application.

Aus diesem Grund werden bei den mehrschichtigen Hybridplatten der eingangs beschriebenen Art, beidseitig Deckschichten hergestellt, die nicht aus (groben) Strands, sondern aus (feinen) Spänen (oder alternativ auch aus Fasern) bestehen, sodass Holzwerkstoffplatten mit hervorragenden optischen Eigenschaften entstehen. Nachteilig ist bei diesen Holzwerkstoffplatten, dass die für die Biegefestigkeit verantwortlichen Strands verhältnismäßig weit von der Oberfläche entfernt sind, sodass damit die Biegefestigkeit gegenüber herkömmlichen OSB-Platten reduziert wird.For this reason, multilayer hybrid panels of the type described above have cover layers on both sides that do not consist of (coarse) strands, but of (fine) chips (or alternatively of fibers), so that wood-based panels with excellent optical properties are created. The disadvantage of these wood-based panels is that the strands responsible for the bending strength are relatively far from the surface, thereby reducing the bending strength compared to conventional OSB boards.

Eine mehrschichtige Holzwerkstoffplatte und ein Verfahren zur Herstellung einer solchen Platte, die eine bzw. mehrere Kernschichten aus Strands und ein oder mehrere Deckschichten aus feineren Partikeln enthält, ist z. B. aus der US 6 461 743 B1 bekannt. Zusätzlich werden dort Papiere mitverarbeitet, um die Eigenschaften der Platte zu verbessern.A multilayer wood-based panel and a method for producing such a panel, which contains one or more core layers of strands and one or more cover layers of finer particles, is known, for example, from US 6 461 743 B1 In addition, papers are processed there to improve the properties of the plate.

Aus der DE 1 202 481 ist ein Verfahren zur Herstellung von mehrschichtigen Holzwerkstoffplatten bekannt, die aus einer dicken Kernschicht von mit Bindemittel versetzten groben Holzteilchen und zwei äußeren, dünneren Deckschichten bestehen, wobei die geschichtete Anordnung unter Druck- und Wärmeanwendung verdichtet wird. Bei diesem Verfahren wird die Kernschicht zwischen zwei Stränge eingebettet, die aus einem Brei von lose verfilzten Cellulosefasern bestehen. Die Holzteile der Kernschicht werden in an sich bekannter Weise mit trockenem, pulverförmigen Bindemittel versetzt. Im Vordergrund steht dabei die Herstellung der dünnflüssigen Fasersuspension für die Deckschichten aus Altpapier. Die Kernschicht kann aus Furnieren hergestellt werden, die in bekannter Weise in mehreren Lagen übereinander mit sich im Wesentlichen rechtwinklig kreuzenden Faserverlauf angeordnet werden.From the EN 1 202 481 A process is known for producing multi-layered wood-based panels that consist of a thick core layer of coarse wood particles mixed with a binding agent and two outer, thinner cover layers, whereby the layered arrangement is compacted using pressure and heat. In this process, the core layer is embedded between two strands consisting of a slurry of loosely matted cellulose fibers. The wooden parts of the core layer are mixed with dry, powdered binding agent in a manner known per se. The focus here is on producing the thin fiber suspension for the cover layers from waste paper. The core layer can be made from veneers that are arranged in a known manner in several layers on top of each other with the fibers crossing essentially at right angles.

Eine Holzwerkstoffplatte, insbesondere OSB-Platte mit ausgerichteten Schmal-Lang-Holzspänen, ist ferner aus der DE 199 13 589 A1 bekannt. Die Platte besteht in Sandwich-Bauweise aus einer Mittelschicht und beidseitigen Deckschichten, wobei die beiden Deckschichten als zumindest Doppelschichten mit einer Außenschicht und einer Innenschicht mit jeweils in unterschiedlichen Richtungen ausgerichteten Holzspänen ausgebildet sind.A wood-based panel, in particular OSB panel with aligned narrow-long wood chips, is also from the DE 199 13 589 A1 The panel is made up of a sandwich construction consisting of a middle layer and cover layers on both sides, whereby the two cover layers are designed as at least double layers with an outer layer and an inner layer, each with wood chips oriented in different directions.

In der DE 10 2005 038 833 B4 wird eine OSB-Platte mit mindestens einer oberen Deckschicht, mindestens einer Mittelschicht und mindestens einer unteren Deckschicht beschrieben, die allesamt aus Harz beleimten Strands bestehen. Zusätzlich ist eine Gewebelage auf der Oberfläche der oberen Deckschicht oder der unteren Deckschicht aufgebracht, um die Biegefestigkeit zu erhöhen.In the EN 10 2005 038 833 B4 describes an OSB board with at least one upper cover layer, at least one middle layer and at least one lower cover layer, all of which consist of resin-bonded strands. In addition, a fabric layer is applied to the surface of the upper cover layer or the lower cover layer to increase the bending strength.

Weitere Beispiele für mehrschichtige Holzwerkstoffplatten und entsprechende Herstellungsverfahren findet man in der DE 10 2017 111 134 B4 , DE 10 2015 120 653 A1 und der DE 20 2017 104 749 U1 .Further examples of multilayer wood-based panels and corresponding manufacturing processes can be found in the EN 10 2017 111 134 B4 , EN 10 2015 120 653 A1 and the EN 20 2017 104 749 U1 .

In der DE 10 2016 110 075 A1 wird eine Vorrichtung und ein Verfahren zur Herstellung einer mehrschichtigen Streugutmatte zur Verpressung in einer Presse im Zuge der Herstellung von Werkstoffplatten beschrieben, wobei mittels eines ersten Streukopfes Grobspäne orientiert zu einer Schicht gestreut werden und mittels eines zweiten Streukopfes Feinspäne orientiert, klassiert und/oder unorientiert als eine weitere Schicht auf die Grobspäne gestreut werden. Das Vorpressen von Schichten vor der Aufstreuung der oberen Deckschicht soll vermeiden, dass sehr lange Grobspäne/Schnitzel im Streugut zur Herstellung der Mittelschicht durch die Deckschichten im Zuge der Verpressung in einer Hauptpresse an die Oberfläche durchstoßen.In the EN 10 2016 110 075 A1 A device and a method for producing a multi-layer grit mat for pressing in a press during the production of material panels are described, whereby coarse chips are scattered in an oriented manner to form a layer using a first scattering head and fine chips are scattered in an oriented, classified and/or unoriented manner as a further layer onto the coarse chips using a second scattering head. The pre-pressing of layers before the upper covering layer is scattered is intended to prevent very long coarse chips/chips in the grit for producing the middle layer from piercing through the covering layers to the surface during pressing in a main press.

Ein weiteres Verfahren zur Herstellung einer OSB-Platte wird in der EP 3 811 314 A1 beschrieben.Another method for producing an OSB board is in the EP 3 811 314 A1 described.

Schließlich beschreibt die US 2014/0370319 A1 die Herstellung einer Werkstoffplatte mit Schichten aus Spänen, die ein unterschiedliches Flächengewicht aufweisen können.Finally, the US 2014/0370319 A1 the production of a material plate with layers of chips that can have different surface weights.

Ausgehend von dem vorbekannten Stand der Technik liegt der Erfindung die Aufgabe zugrunde, eine Werkstoffplatte der eingangs beschriebenen Art zu schaffen, die sich bei einfachem Aufbau und wirtschaftlicher Herstellung sowohl durch eine hohe Biegesteifigkeit als auch durch eine einwandfreie Oberflächenbeschaffenheit auszeichnet.Based on the previously known state of the art, the object of the invention is to create a material plate of the type described at the outset, which is characterized by both high flexural rigidity and a perfect surface finish while being simple in construction and economical in production.

Zur Lösung dieser Aufgabe lehrt die Erfindung eineWerkstoffplatte mit den Merkmalen des Anspruchs 1 und ein Verfahren mit den Merkmalen des Anspruchs 7. Es ist vorgesehen, dass eine oder vorzugsweise beide Deckschichten als nicht vollflächige Deckschichten derart ausgebildet sind, dass einzelne Strands zumindest teilweise durch die jeweilige Deckschicht hindurch unter Bildung von Unterbrechungen der Deckschicht bis an die Plattenoberfläche reichen und damit sichtbar sind.To achieve this object, the invention teaches a material plate with the features of claim 1 and a method with the features of claim 7. It is provided that one or preferably both cover layers are designed as non-full-surface cover layers in such a way that individual strands extend at least partially through the respective cover layer to the plate surface, forming interruptions in the cover layer, and are thus visible.

Die Erfindung geht dabei von der Erkenntnis aus, dass sich Platten, z. B. Holzwerkstoffplatten mit besonders hoher Biegesteifigkeit bzw. Biegefestigkeit auf OSB-Basis und folglich aus Strands herstellen lassen, und zwar bevorzugt aus mehreren Lagen von Strands mit unterschiedlicher Orientierung. Ferner geht die Erfindung von der Erkenntnis aus, dass es zur Verbesserung der Oberflächeneigenschaften grundsätzlich vorteilhaft ist, eine solche OSB-Kernschicht bzw. solche OSB-Kernschichten beidseitig mit Deckschichten aus Spänen und insbesondere feinen Spänen zu versehen. Dabei hat die Erfindung jedoch erkannt, dass es zur Verbesserung der Oberflächeneigenschaften nicht erforderlich ist, die Deckschichten aus feinem Material in einer so großen Dicke herzustellen, dass die Deckschichten die OSB-Kernschichten vollständig bedecken. Denn erfindungsgemäß werden beidseitig auf die OSB-Kernschicht lediglich sehr dünne, nicht vollständig deckende Deckschichten aufgebracht, die lediglich dazu bestimmt sind, die im Zuge des Streuprozesses außenseitig auf der Kernschicht oder auf den Kernschichten entstehenden Zwischenräume zwischen den einzelnen Grobspänen auszufüllen und einzuebnen. Dieses ist zum einen deshalb vorteilhaft, weil lediglich sehr geringe Mengen an Spänen und folglich feinem Material benötigt werden, um die unebene Oberfläche der OSB-Schichten auszugleichen. Besonders vorteilhaft ist jedoch die Tatsache, dass die Biegesteifigkeit der Holzwerkstoffplatte, die im Wesentlichen durch die OSB-Kernschicht gewährleistet wird, nur unwesentlich beeinträchtigt wird, da die Deckschichten aus feinem Material extrem dünn und nicht vollflächig ausgebildet sind. Insgesamt wird eine Holzwerkstoffplatte geschaffen, die sich einfach und kostengünstig herstellen lässt und dennoch sowohl hervorragende Festigkeitseigenschaften als auch eine gute Oberflächenqualität besitzt. Damit eignet sich die Platte insbesondere für eine Weiterverarbeitung durch z. B. Beschichtung oder einem Farbauftrag.The invention is based on the knowledge that panels, e.g. wood-based panels with particularly high flexural rigidity or flexural strength can be produced on an OSB basis and therefore from strands, preferably from several layers of strands with different orientations. The invention is also based on the knowledge that, in order to improve the surface properties, it is fundamentally advantageous to provide such an OSB core layer or such OSB core layers on both sides with cover layers made of chips and in particular fine chips. However, the invention has recognized that, in order to improve the surface properties, it is not necessary to produce the cover layers from fine material in such a thick layer that the cover layers completely cover the OSB core layers. According to the invention, only very thin, not completely covering cover layers are applied to both sides of the OSB core layer, which are only intended to cover the outside of the OSB during the spreading process. the core layer or on the core layers to fill and level the gaps between the individual coarse chips. This is advantageous because only very small amounts of chips and therefore fine material are needed to even out the uneven surface of the OSB layers. However, a particularly advantageous feature is the fact that the flexural rigidity of the wood-based panel, which is essentially ensured by the OSB core layer, is only slightly impaired because the cover layers made of fine material are extremely thin and do not cover the entire surface. Overall, a wood-based panel is created that is easy and inexpensive to manufacture and yet has both excellent strength properties and a good surface quality. This makes the panel particularly suitable for further processing, for example by coating or applying paint.

Als Partikel sowohl für die Kernschicht als auch für die Deckschicht werden erfindungsgemäß pflanzliche Partikel und folglich lignocellulosehaltige Partikel verwendet, insbesondere aus Mehrjahrespflanzen (Holz). So werden besonders bevorzugt für die Kernschicht Strands aus Holz bzw. Holzwerkstoffen verwendet. Alternativ können für die Strands aber auch Einjahrespflanzen, z. B. grasartige Pflanzen, Stroh oder dergleichen verwendet werden. Auch bei den Spänen für die Deckschichten handelt es sich um pflanzliche Partikel, das heißt lignocellulosehaltige Partikel. Besonders bevorzugt werden Späne aus Mehrjahrespflanzen (Holzspäne) verwendet. Alternativ können aber auch Späne mit den angegebenen Dimensionen aus Einjahrespflanzen verwendet werden, z. B. aus grasartigen Pflanzen, Stroh oder dergleichen.According to the invention, plant particles and therefore lignocellulose-containing particles are used as particles for both the core layer and the cover layer, in particular from perennial plants (wood). Strands made of wood or wood materials are particularly preferably used for the core layer. Alternatively, however, annual plants, e.g. grass-like plants, straw or the like, can also be used for the strands. The chips for the cover layers are also plant particles, i.e. lignocellulose-containing particles. Particularly preferably, chips made from perennial plants (wood chips) are used. Alternatively, however, chips with the specified dimensions made from annual plants can also be used, e.g. from grass-like plants, straw or the like.

Zur Verbesserung der mechanischen Eigenschaften der Platte wird bevorzugt nicht nur eine einzelne bzw. homogene Kernschicht aus Strands verwendet, sondern es werden zwischen den Deckschichten mehrere Kernschichten aus Strands oder eine Kernschicht aus mehreren Lagen angeordnet, deren Strands in unterschiedlichen Richtungen orientiert sind. So können insbesondere drei Lagen in der Kernschicht vorgesehen sein, z. B. eine mittlere Lage und zwei äußere Lagen, wobei an die beiden äußeren Lagen der Kernschicht die Deckschichten aus Span grenzen. Bevorzugt sind die Strands in der mittleren Lage der Kernschicht quer zur Plattenlängsrichtung und folglich quer zur Transportrichtung der Matte bzw. Platte während des Herstellungsprozesses orientiert. Die beiden äußeren Lagen der Kernschicht sind bevorzugt in Längsrichtung und folglich entlang der Längsrichtung der Platte bzw. der Transportrichtung orientiert.To improve the mechanical properties of the board, it is preferable not to use just a single or homogeneous core layer made of strands, but to use several core layers made of Strands or a core layer made up of several layers, the strands of which are oriented in different directions. In particular, three layers can be provided in the core layer, e.g. a middle layer and two outer layers, with the cover layers made of chipboard bordering the two outer layers of the core layer. The strands in the middle layer of the core layer are preferably oriented transversely to the longitudinal direction of the panel and thus transversely to the transport direction of the mat or panel during the manufacturing process. The two outer layers of the core layer are preferably oriented longitudinally and thus along the longitudinal direction of the panel or the transport direction.

Die Kernschicht (oder die mehreren Kernschichten) können bevorzugt (zusammen) ein Flächengewicht von mehr als 5 kg/m2 aufweisen, z. B. ein Flächengewicht von 5 bis 15 kg/m2.The core layer (or the plurality of core layers) may preferably (together) have a basis weight of more than 5 kg/m 2 , e.g. a basis weight of 5 to 15 kg/m 2 .

Von besonderer Bedeutung ist, dass mit sehr dünnen Deckschichten bzw. wenig Deckschichtmaterial gearbeitet wird. So ist es zweckmäßig, Deckschichten (aus Spänen) mit einem Flächengewicht von jeweils weniger als 1,5 kg/m2, vorzugsweise weniger als 1 kg/m2 zu verwenden.It is particularly important to work with very thin covering layers or with little covering layer material. It is therefore advisable to use covering layers (made of chips) with a weight per unit area of less than 1.5 kg/m 2 , preferably less than 1 kg/m 2 .

Nach einem weiteren Vorschlag der Erfindung ist vorgesehen, dass die beiden Deckschichten (aus Spänen bzw. Feinspänen) ein unterschiedliches Flächengewicht aufweisen, wobei vorzugsweise das Flächengewicht einer Deckschicht, z. B. der oberen Deckschicht zumindest 10 % größer ist als das Flächengewicht der anderen Deckschicht, z. B. der unteren Deckschicht, besonders bevorzugt zumindest 15 % größer. Dabei geht die Erfindung von der Erkenntnis aus, dass im Zuge der Herstellung zunächst eine mehrschichtige Pressgutmatte erzeugt wird, die anschließend in einer Presse unter Anwendung von Druck und Wärme verpresst wird. Dabei besteht die Möglichkeit, auf einen Bandförderer in einer Formstation bzw. Formstraße zunächst das Deckschichtmaterial für die untere Deckschicht aufzustreuen, darauf anschließend die eine Kernschicht oder die mehreren Kernschichten aus Strands aufzustreuen und anschließend auf diese Kernschicht bzw. die oberste Kernschicht die obere Deckschicht bzw. das Material für die obere Deckschicht (Span bzw. Feinspan) aufzustreuen. Während das Material für die untere Deckschicht flach auf dem Bandförderer aufliegt, kann das Material für die obere Deckschicht in die zuvor aufgestreute Kernschicht und folglich in den Bereich zwischen den Strands einrieseln, sodass zur Erzielung optimaler Platteneigenschaften für die obere Deckschicht bzw. die obere Pressgutschicht etwas mehr Material verwendet wird als für die untere Deckschicht.According to a further proposal of the invention, it is provided that the two cover layers (made of chips or fine chips) have a different weight per unit area, whereby the weight per unit area of one cover layer, e.g. the upper cover layer, is preferably at least 10% greater than the weight per unit area of the other cover layer, e.g. the lower cover layer, particularly preferably at least 15% greater. The invention is based on the knowledge that in the course of production, a multi-layered mat of pressed material is first produced, which is then pressed in a press using pressure and heat. In this case, it is possible to use a Belt conveyors in a forming station or forming line first spread the covering layer material for the lower covering layer, then spread the one core layer or several core layers made of strands on top of that, and then spread the upper covering layer or the material for the upper covering layer (chips or fine chips) on this core layer or the upper core layer. While the material for the lower covering layer lies flat on the belt conveyor, the material for the upper covering layer can trickle into the previously spread core layer and consequently into the area between the strands, so that in order to achieve optimal panel properties, slightly more material is used for the upper covering layer or the upper pressed material layer than for the lower covering layer.

Die Erfindung betrifft folglich nicht nur die Werkstoffplatte bzw. Holzwerkstoffplatte, sondern auch ein Verfahren zum Herstellen einer Werkstoffplatte bzw. Holzwerkstoffplatte, wobei eine mehrschichtige Pressgutmatte mit zumindest einer (mittleren) Kern-Pressgutschicht aus Strands (bzw. Grobspänen) und einer unteren und einer oberen Deck-Pressgutschicht aus Spänen (bzw. Feinspänen) erzeugt wird und wobei die mehrschichtige Pressgutmatte unter Bildung der (Holz)Werkstoffplatte mit Mittelschicht und Deckschichten verpresst wird. Die Matte kann in bekannter Weise in einer kontinuierlich arbeitenden Presse (z. B. Doppelbandpresse) oder alternativ in einer Taktpresse verpresst werden. Optional können die Oberflächen der Deckschichten nach dem Pressen abgeschliffen werden. Von besonderer Bedeutung ist die Tatsache, dass bei der auf diese Weise hergestellten Holzwerkstoffplatte die Deckschichten als nicht vollflächige Deckschichten derart ausgebildet sind, dass einzelne Strands zumindest teilweise durch die Deckschicht hindurch unter Bildung von Unterbrechungen der Deckschicht bis an die Plattenoberfläche reichen und damit sichtbar sind. Die Strands erstrecken sich folglich partiell aber auch nur partiell über die gesamte Dicke der Platte, das heißt an einigen Stellen der Platte sind über die gesamte Dicke Strands angeordnet.The invention therefore relates not only to the material board or wood-based material board, but also to a method for producing a material board or wood-based material board, whereby a multi-layered pressed material mat is produced with at least one (middle) core pressed material layer made of strands (or coarse chips) and a lower and an upper cover pressed material layer made of chips (or fine chips), and whereby the multi-layered pressed material mat is pressed to form the (wood) material board with middle layer and cover layers. The mat can be pressed in a known manner in a continuously operating press (e.g. double belt press) or alternatively in a cycle press. Optionally, the surfaces of the cover layers can be sanded down after pressing. Of particular importance is the fact that in the wood-based material board produced in this way, the cover layers are designed as non-full-surface cover layers in such a way that individual strands extend at least partially through the cover layer to the board surface, forming interruptions in the cover layer, and are thus visible. The beaches therefore extend partially but only partially over the entire thickness of the plate, i.e. in some places on the plate strands are arranged across the entire thickness.

Dazuwerden die untere und die obere Deck-Pressgutschicht zunächst derart erzeugt, dass im Zuge des Pressens zunächst vollflächige Deckschichten mit geschlossener Oberfläche aus Deckschicht-Spänen entstehen und dass anschließend durch eine Oberflächenbearbeitung, z. B. durch das Abschleifen der Deckschichten die nicht vollflächigen Deckschichten entstehen und einzelne Strands zumindest teilweise durch die Deckschichten hindurch unter Bildung von Durchbrechungen der Deckschichten bis an die Plattenoberfläche reichen und damit sichtbar werden. Bei dieser erfindungsgemäßenHerstellungsart entstehen folglich in einem Zwischenschritt zunächst Holzwerkstoffplatten mit vollständig geschlossenen Span-Oberflächen, die jedoch anschließend (unmittelbar) durch eine spanabhebende Bearbeitung, z. B. ein Schleifprozess "geöffnet" werden, sodass nach diesem zusätzlichen Verfahrensschritt die erfindungsgemäße Holzwerkstoffplatte zur Verfügung steht.For this purpose, the lower and upper cover pressed material layers are first produced in such a way that, during the pressing process, full-surface cover layers with a closed surface are created from cover layer chips and that the non-full-surface cover layers are then created by surface processing, e.g. by sanding the cover layers, and individual strands extend at least partially through the cover layers to the board surface, forming breaks in the cover layers, and thus become visible. In this method of production according to the invention, wood-based panels with completely closed chip surfaces are therefore initially created in an intermediate step, which are then (immediately) "opened" by machining, e.g. a sanding process, so that the wood-based panel according to the invention is available after this additional process step.

Es ist zweckmäßig, die Kern-Pressgutschicht (das heißt die OSB-Schicht bzw. die OSB-Schichten) in grundsätzlich bekannter Weise aus streufähigen bzw. rieselfähigen Strands durch einen Streuprozess zu erzeugen, und zwar bevorzugt aus Strands, die mit einem üblichen Bindemittel versetzt sind. Dabei kann auf grundsätzlich bekannte Streumaschinen oder Streumaschinenanordnungen mit einem oder mehreren Streuköpfen zurückgegriffen werden, sodass in bekannter Weise ein oder mehrere Kern-Pressgutschichten (bzw. Lagen) aus Strands mit der jeweils gewünschten Orientierung erzeugt werden können. Die Deck-Pressgutschichten können in einer möglichen Ausführungsform der Erfindung aus rieselfähigen und folglich streufähigen Spänen ebenfalls durch einen Streuprozess erzeugt werden, wobei bevorzugt Späne verwendet werden, die mit einem Bindemittel versetzt sind. Insofern kann auch dabei auf bekannte Streumaschinen zurückgegriffen werden, sodass in einer möglichen Ausführungsform zunächst auf das Streuband das Material für die untere Deckschicht, darauf dann die Strands für die Kernschicht bzw. die Kernschichten und darauf schließlich das Material für die obere Deckschicht gestreut werden, sodass anschließend eine mehrschichtige Pressgutmatte in eine Presse eingeführt und unter Anwendung von Druck und Wärme verpresst wird.It is expedient to produce the core pressed material layer (i.e. the OSB layer or layers) in a generally known manner from scatterable or free-flowing strands by means of a scattering process, preferably from strands that are mixed with a conventional binding agent. In this case, generally known scattering machines or scattering machine arrangements with one or more scattering heads can be used, so that one or more core pressed material layers (or layers) can be produced from strands with the desired orientation in a generally known manner. In one possible embodiment of the invention, the cover pressed material layers can also be produced from free-flowing and therefore scatterable chips by means of a scattering process. Preferably, chips mixed with a binding agent are used. In this respect, known spreading machines can also be used, so that in one possible embodiment, the material for the lower cover layer is first spread on the spreading belt, then the strands for the core layer or core layers and finally the material for the upper cover layer, so that a multi-layer mat of pressed material is then introduced into a press and pressed using pressure and heat.

In einer alternativen Ausführungsform werden die Deckschichten nicht in klassischer Weise aus rieselfähigem Material durch einen Streuprozess erzeugt, sondern aus einem fließfähigen, breiartigen und gegebenenfalls zähflüssigen Span-Flüssigkeitsgemisch erzeugt. Bei dieser Variante lassen sich die Deckschichten besonders dünn und damit besonders wirtschaftlich aufbringen. Im Zuge des Pressprozesses kann die breiartige Schicht zerfließen und damit einwandfrei die Zwischenräume zwischen den OSB-Spänen ausfüllen und die Oberflächen einebnen. Dieses hängt auch damit zusammen, dass der Brei zwar aus Spänen grundsätzlich bekannter Größe erzeugt werden kann, dass in dieser Konsistenz die Späne jedoch eine noch kleinere Dimension erhalten und sich damit noch feiner verteilen. In dieser möglichen Ausführungsform der Erfindung werden die Deck-Pressgutschichten aus dem fließfähigen Span-Flüssigkeitsgemisch nach Art einer Suspension hergestellt, die einerseits feste Partikel (Späne) und andererseits eine Flüssigkeit, z. B. Wasser, wie außerdem bevorzugt ein Bindemittel (z. B. Leim) enthält. Bei dieser Ausführungsform wird ein fließfähiges Gemisch verwendet, das heißt die Mischung aus Spänen und der Flüssigkeit (insbesondere Wasser, aber auch Leim- und Waschemulsion sowie andere flüssige Zuschlagstoffe) werden so eingestellt, dass die resultierende Viskosität der Mischung weiterhin fließfähig ist. Dabei beträgt der Anteil der Flüssigkeit in dem Gemisch mehr als 100 % des Anteils der (trockenen) Späne, und zwar bezogen auf das Gewicht, besonders bevorzugt mehr als 200 %. Das bedeutet, dass innerhalb der Mischung des Flüssigkeitsanteils zumindest so groß ist, wie der Spananteil, vorzugsweise zumindest das 2-fache (das heißt 200 %), besonders bevorzugt zumindest das 3-fache (das heißt 300 %) beträgt, und zwar jeweils bezogen auf das Gewicht.In an alternative embodiment, the cover layers are not produced in the classic way from free-flowing material through a scattering process, but from a flowable, pasty and possibly viscous chip-liquid mixture. In this variant, the cover layers can be applied particularly thinly and thus particularly economically. During the pressing process, the pasty layer can flow and thus perfectly fill the gaps between the OSB chips and level the surfaces. This is also related to the fact that the paste can be produced from chips of a known size, but that in this consistency the chips are even smaller and thus spread even more finely. In this possible embodiment of the invention, the cover pressed material layers are produced from the flowable chip-liquid mixture in the manner of a suspension, which on the one hand contains solid particles (chips) and on the other hand a liquid, e.g. water, and also preferably a binding agent (e.g. glue). In this embodiment, a flowable mixture is used, i.e. the mixture of chips and the liquid (especially water, but also glue and washing emulsion as well as other liquid additives) is adjusted so that the resulting viscosity of the mixture remains flowable. The proportion of liquid in the mixture is more than 100% of the Proportion of (dry) chips, based on weight, particularly preferably more than 200%. This means that within the mixture the liquid portion is at least as large as the chip portion, preferably at least twice (i.e. 200%), particularly preferably at least three times (i.e. 300%), in each case based on weight.

Das fließfähige Flüssigkeits-Span-Gemisch lässt sich auf verschiedene Arten herstellen. Es besteht z. B. die Möglichkeit, ein Flüssigkeits-Leim-Gemisch herzustellen und andererseits die Holzpartikel in bekannter Weise in einer Mühle auf die gewünschte Größe zu verkleinern und anschließend die Holzpartikel mit dem Flüssigkeits-Leim-Gemisch zu vermischen, z. B. in einem separaten Mischer.The flowable liquid-chip mixture can be produced in various ways. For example, it is possible to produce a liquid-glue mixture and, on the other hand, to reduce the wood particles to the desired size in a mill in the usual way and then to mix the wood particles with the liquid-glue mixture, e.g. in a separate mixer.

Alternativ kann ein Flüssigkeits-Leim-Gemisch den Holzpartikeln in der Mühle und folglich im Zerkleinerungsprozess beigegeben werden, sodass in der Mühle solgleich die Vermischung mit der Flüssigkeit erfolgt. Alternativ können die Flüssigkeit, der Leim und die Holzpartikel jeweils getrennt der Mühle zugegeben werden, sodass in der Mühle eine Vermischung der drei Komponenten unter Bildung des Flüssigkeits-Holzgemisches erfolgt.Alternatively, a liquid-glue mixture can be added to the wood particles in the mill and thus in the crushing process, so that mixing with the liquid takes place in the mill. Alternatively, the liquid, the glue and the wood particles can each be added separately to the mill, so that the three components are mixed in the mill to form the liquid-wood mixture.

Das auf diese Weise hergestellte fließfähige Gemisch bzw. der Brei können durch verschiedene Methoden zu den bahnartigen Schichten verarbeitet werden, z. B. durch Extrusion. Insofern kann z. B. die untere Schicht auf den Förderer aufextrudiert werden. Darauf wird anschließend die OSB-Schicht in bekannter Weise aufgestreut und darauf wird dann wiederum die obere Deckschicht bzw. das Material für die obere Deckschicht aufextrudiert. Alternativ kann auch ein Walzenauftrag erfolgen.The flowable mixture or slurry produced in this way can be processed into web-like layers using various methods, e.g. by extrusion. In this respect, the lower layer can be extruded onto the conveyor. The OSB layer is then spread on top of this in the usual way and the upper covering layer or the material for the upper covering layer is then extruded onto this. Alternatively, it can also be applied using a roller.

Von besonderer Bedeutung ist erfindungsgemäß, dass für die einzelnen Schichten grundsätzlich bekannte Partikel, z. B. Holzwerkstoff-Partikel, verwendet werden können, und zwar für die Kernschicht ausdrücklich Strands, die für die OSB-Herstellung üblich sind. Strands meint im Rahmen der Erfindung lange, schmale Späne mit einer Länge von mehr als 50 mm, vorzugsweise mehr als 80 mm, z. B. 100 mm bis 200 mm und mit einer mittleren Breite von mehr als 5 mm, vorzugsweise mehr als 8 mm, z. B. 10 mm bis 50 mm sowie mit einer Dicke von mehr als 0,5 mm, z. B. 0,6 mm bis 1,5 mm.Of particular importance according to the invention is that basically known particles, e.g. wood material particles, can be used for the individual layers, and specifically strands for the core layer, which are common for OSB production. In the context of the invention, strands mean long, narrow chips with a length of more than 50 mm, preferably more than 80 mm, e.g. 100 mm to 200 mm and with an average width of more than 5 mm, preferably more than 8 mm, e.g. 10 mm to 50 mm and with a thickness of more than 0.5 mm, e.g. 0.6 mm to 1.5 mm.

Als Späne (für die Deckschichten) werden erfindungsgemäß herkömmliche Späne verstanden, die deutlich kleiner sind als die Strands der Kernschicht. Späne meint Holzpartikel mit einer Länge von weniger als 20 mm, vorzugsweise weniger als 10 mm und mit einer mittleren Breite und einer mittleren Dicke von weniger als 2 mm, vorzugsweise weniger als 1 mm. Besonders bevorzugt werden für die Deckschichten feine Späne bzw. Feinspäne mit einer Größe (im trockenen Zustand) verwendet, die einem Siebdurchgang von weniger als 2 mm, vorzugsweise weniger als 1 mm, besonders bevorzugt weniger als 0,5 mm entspricht.According to the invention, chips (for the cover layers) are understood to mean conventional chips that are significantly smaller than the strands of the core layer. Chips means wood particles with a length of less than 20 mm, preferably less than 10 mm, and with an average width and an average thickness of less than 2 mm, preferably less than 1 mm. It is particularly preferred to use fine chips or fine chips with a size (in the dry state) that corresponds to a sieve passage of less than 2 mm, preferably less than 1 mm, particularly preferably less than 0.5 mm for the cover layers.

Strands und Späne, die erfindungsgemäß verwendet werden, werden durch (mechanische) Zerkleinerung aus dem Ausgangsprodukt (z. B. Holz) hergestellt und sind von den ebenfalls bekannten Fasern (z. B. für MDF) zu unterscheiden, die erfindungsgemäß nicht eingesetzt werden.Strands and chips used according to the invention are produced by (mechanical) comminution of the starting product (e.g. wood) and are to be distinguished from the also known fibers (e.g. for MDF), which are not used according to the invention.

Stets werden bevorzugt Partikel (Strands und Späne) verwendet, die mit einem Bindemittel versetzt sind. Dabei kann auf grundsätzlich bekannte Bindemittel für die Herstellung von Holzwerkstoffplatten zurückgegriffen werden. So können als Bindemittel z. B. Isocyanate bzw. auf Isocyanatbasis verwendet werden (pMDI).Particles (strands and chips) mixed with a binding agent are always preferred. Basically known binding agents for the production of wood-based panels can be used. For example, isocyanates or isocyanate-based binding agents (pMDI) can be used as binding agents.

Alternativ kann ein Harnstoffharz bzw. ein Bindemittel auf Basis von Harnstoffharz (UF) zum Einsatz kommen. Ferner können Phenolleime (PF) oder melaminverstärkte UF (MUF) eingesetzt werden. Diese können gegebenenfalls mit Phenol versehen sein (MUPF, UMPF).Alternatively, a urea resin or a binder based on urea resin (UF) can be used. Phenolic glues (PF) or melamine-reinforced UF (MUF) can also be used. These can optionally be provided with phenol (MUPF, UMPF).

Im Folgenden wird die Erfindung anhand von Zeichnungen näher erläutert, die lediglich ein Ausführungsbeispiel darstellen. Es zeigen

Fig. 1
eine erfindungsgemäße Holzwerkstoffplatte in einem vereinfachten Vertikalschnitt,
Fig. 2
eine Draufsicht auf die Oberfläche einer erfindungsgemäßen Holzwerkstoffplatte (Ausschnitt),
Fig. 3
einen Vertikalschnitt durch eine Pressgutmatte für die Herstellung einer erfindungsgemäßen Platte nach Fig. 1,
Fig. 4
eine mögliche Anlage für die Herstellung einer erfindungsgemäßen Holzwerkstoffplatte in einer stark vereinfachten Seitenansicht.
In the following, the invention is explained in more detail with reference to drawings which merely represent an embodiment. They show
Fig.1
a wood-based panel according to the invention in a simplified vertical section,
Fig. 2
a plan view of the surface of a wood-based panel according to the invention (detail),
Fig.3
a vertical section through a pressed material mat for the production of a plate according to the invention according to Fig.1 ,
Fig.4
a possible system for the production of a wood-based panel according to the invention in a highly simplified side view.

In Fig. 1 ist eine erfindungsgemäße Holzwerkstoffplatte 1 in einem vereinfachten Vertikalschnitt dargestellt, die einerseits eine Kernschicht 2 aus Strands 3 und andererseits eine obere Deckschicht 4 sowie eine untere Deckschicht 5 aus Spänen 6 aufweist. In dem dargestellten Ausführungsbeispiel besteht die Kernschicht 2 aus mehreren Lagen 2a, 2b, 2c, die jeweils aus Strands 3 bestehen, wobei die Strands 3 in den Einzellagen 2a, 2b, 2c orientiert sind. Die Figuren zeigen dabei eine mögliche Ausführungsform, bei welcher die Strands 3 in der mittleren Lage 2b quer zur Plattenlängsrichtung bzw. Produktionsrichtung P verlaufen. Die Strands 3 der oberen Lage 2a und der unteren Lage 2c sind längsorientiert, das heißt sie verlaufen mit ihrer Längsrichtung entlang der Plattenlängsrichtung dieser Produktionsrichtung P. Solche Holzwerkstoffplatten mit mehrlagigen Kernschichten und jeweils oberer und unterer Deckschicht sind aus dem Stand der Technik grundsätzlich bekannt. Erfindungsgemäß ist vorgesehen, dass die Strands 3 bzw. dass einzelne Strands zumindest teilweise durch die Deckschicht 4, 5 hindurch unter Bildung von Unterbrechungen der jeweiligen Deckschicht 4, 5 bis an die Plattenoberfläche reichen und damit sichtbar sind. Dieses ergibt sich aus einer vergleichenden Betrachtung der Figuren 1 und 2. Es ist angedeutet, dass die Deckschichten 4, 5 nicht vollflächig an der Oberfläche durchgehen, sondern dass einzelne Strands 3 bis an die Oberfläche ragen, sodass sie z. B. in der Draufsicht nach Fig. 2 auf die Deckschicht 4 unmittelbar sichtbar sind. Obwohl folglich bei der erfindungsgemäßen Platte eine obere Deckschicht 4 aus (feinen) Spänen 6 vorgesehen ist, ist diese erfindungsgemäß so dünn ausgebildet, dass einzelne Strands 3 bis an die Oberfläche und folglich durch die Deckschichten 4, 5 hindurchragen und damit sichtbar sind. Es werden folglich lediglich sehr geringe Mengen an Deckschichtspänen 6 verwendet und diese dienen (nur) dazu, die verhältnismäßig groben Oberflächen der OSB-Platte einzuebnen bzw. auszugleichen, sodass eine Holzwerkstoffplatte 1 mit einwandfreier Oberflächenqualität zur Verfügung gestellt wird. Dabei ist in Fig. 2 zu beachten, dass von den Strands 3 in dieser Darstellung in den meisten Fällen lediglich Teile zu sehen sind, da diese Strands zum Teil unter der Oberfläche liegen und lediglich deren Enden bzw. Abschnitte bis an die Oberfläche ragen und von der Oberfläche aus sichtbar sind.In Fig.1 a wood-based panel 1 according to the invention is shown in a simplified vertical section, which has on the one hand a core layer 2 made of strands 3 and on the other hand an upper cover layer 4 and a lower cover layer 5 made of chips 6. In the embodiment shown, the core layer 2 consists of several layers 2a, 2b, 2c, each of which consists of strands 3, the strands 3 being oriented in the individual layers 2a, 2b, 2c. The figures show a possible embodiment in which the strands 3 in the middle layer 2b are transverse to the longitudinal direction of the panel or production direction P. The strands 3 of the upper layer 2a and the lower layer 2c are longitudinally oriented, i.e. they run with their longitudinal direction along the longitudinal direction of the board in this production direction P. Such wood-based panels with multi-layer core layers and upper and lower cover layers are basically known from the prior art. According to the invention, it is provided that the strands 3 or that individual strands extend at least partially through the cover layer 4, 5 to the board surface, forming interruptions in the respective cover layer 4, 5, and are thus visible. This results from a comparative examination of the Figures 1 and 2 It is indicated that the cover layers 4, 5 do not extend completely to the surface, but that individual strands 3 protrude to the surface, so that, for example, in the top view, they Fig. 2 on the cover layer 4 are immediately visible. Although an upper cover layer 4 made of (fine) chips 6 is provided in the board according to the invention, this is designed so thinly according to the invention that individual strands 3 protrude to the surface and consequently through the cover layers 4, 5 and are thus visible. Consequently, only very small amounts of cover layer chips 6 are used and these serve (only) to level or even out the relatively coarse surfaces of the OSB board, so that a wood-based panel 1 with perfect surface quality is provided. Fig. 2 Please note that in most cases only parts of Strands 3 can be seen in this illustration, as these strands are partly below the surface and only their ends or sections protrude to the surface and are visible from the surface.

Hergestellt wird eine solche Holzwerkstoffplatte nach Figuren 1 und 2, indem zunächst eine mehrschichtige Pressgutmatte 1' hergestellt wird, die eine Kernpressgutschicht 1' aus Strands sowie eine obere Deckpressgutschicht 4' aus Spänen und eine untere Deckpressgutschicht 5' aus Spänen 6 aufweist. Eine solche Pressgutmatte 1', die auf einem Formband 7 erzeugt wird, ist in Fig. 3 dargestellt. Diese Pressgutmatte 1' lässt sich z. B. in einer Presse 8 unter Anwendung von Druck und Wärme unter Bildung der Holzwerkstoffplatte nach Fig. 1 verpressen. Dabei zeigen die Figuren eine Ausführungsform, bei der die Schichten in einer nicht erfindungsgemäßen Weise bei der Herstellung der Pressgutmatte 1' derart erzeugt werden, dass im Zuge des Pressens in der Presse 8 unmittelbar die Holzwerkstoffplatte 1 entsteht, bei der die Strands der Kernschicht 2 durch die Deckschichten 4, 5 hindurch an die Oberfläche reichen und damit sichtbar werden. In Fig. 3 ist dabei beispielhaft eine Pressgutmatte 1' dargestellt, bei der sämtliche Schichten aus streufähigem, rieselfähigem Pressgut erzeugt werden, das heißt sowohl die Deck-Pressgutschichten 4', 5' als auch die Kern-Pressgutschicht 2` werden aus Spänen bzw. Strands in rieselfähiger Form mit üblichen Streuvorrichtungen nacheinander auf dem Formband 7 erzeugt bzw. aufgestreut. Dabei handelt es sich in grundsätzlich bekannter Weise um Partikel 3, 6, die mit einem Bindemittel versehen sind.Such a wood-based panel is manufactured according to Figures 1 and 2 by first producing a multi-layered pressed material mat 1', which comprises a core pressed material layer 1' made of strands and an upper cover pressed material layer 4' of chips and a lower cover pressed material layer 5' of chips 6. Such a pressed material mat 1', which is produced on a forming belt 7, is in Fig.3 This pressed material mat 1' can be pressed, for example, in a press 8 using pressure and heat to form the wood-based panel according to Fig.1 The figures show an embodiment in which the layers are produced in a manner not according to the invention during the manufacture of the pressed material mat 1' in such a way that during the pressing in the press 8 the wood-based panel 1 is produced directly, in which the strands of the core layer 2 extend through the cover layers 4, 5 to the surface and thus become visible. In Fig.3 As an example, a pressed material mat 1' is shown in which all layers are produced from scatterable, free-flowing pressed material, i.e. both the cover pressed material layers 4', 5' and the core pressed material layer 2' are produced or scattered one after the other on the forming belt 7 from chips or strands in free-flowing form using conventional scattering devices. In a basically known manner, these are particles 3, 6 which are provided with a binding agent.

Zu der Fig. 1 wurde bereits erläutert, dass die Kernschicht 2 aus mehreren Lagen 2a, 2b, 2c mit unterschiedlichen Strand-Orientierungen besteht. Dazu wird gemäß Fig. 3 eine Pressgutmatte 1' erzeugt, bei der die Kern-Pressgutschicht 2' wiederum aus mehreren Lagen 2a`, 2b', 2c' mit den entsprechenden Orientierungen der Strands 3 erzeugt wird. Auch dieses ist in Fig. 3 durch die unterschiedliche Darstellung der Strands 6 in den einzelnen Lagen 2a`, 2b`, 2c' angedeutet.To the Fig.1 It has already been explained that the core layer 2 consists of several layers 2a, 2b, 2c with different strand orientations. For this purpose, according to Fig.3 a pressed material mat 1' is produced, in which the core pressed material layer 2' is again produced from several layers 2a`, 2b', 2c' with the corresponding orientations of the strands 3. This is also in Fig.3 indicated by the different representation of the strands 6 in the individual layers 2a`, 2b`, 2c'.

Bei dieser Ausführungsform ist es im Übrigen zweckmäßig, wenn für die beiden Deckschichten 4, 5 Späne bzw. Schichten mit einem unterschiedlichen Flächengewicht verwendet werden. So ist in Fig. 3 angedeutet, dass für die untere Deck-Pressgutschicht 5' etwas weniger Späne 6 verwendet werden können als für die obere Deck-Pressgutschicht 4`. Hintergrund ist die Überlegung, dass die untere Deck-Pressgutschicht 5' zunächst im Wesentlichen geschlossen und flach auf das Formband 7 aufgebracht wird, während die auf die Kernschicht 2' applizierte obere Deck-Pressgutschicht 4' zum Teil in die Oberfläche einrieselt. Hierdurch bilden sich nach dem Verpressen ungleiche Zugspannungen der Decklagen aus. Durch die ungleichen Flächengewichte der beiden Feinspan-Deckschichten gleicht sich dieses im Pressprozess aus, sodass eine Holzwerkstoffplatte 1 mit einwandfreien Eigenschaften erzeugt wirdIn this embodiment, it is also expedient if chips or layers with a different basis weight are used for the two cover layers 4, 5. In this way, Fig.3 indicated that slightly less chips 6 are used for the lower cover pressed material layer 5' than for the upper cover pressed material layer 4'. The background to this is the consideration that the lower cover pressed material layer 5' is initially applied essentially closed and flat to the forming belt 7, while the upper cover pressed material layer 4' applied to the core layer 2' partially trickles into the surface. As a result, unequal tensile stresses are formed in the cover layers after pressing. Due to the unequal surface weights of the two fine chip cover layers, this is balanced out in the pressing process, so that a wood-based panel 1 with perfect properties is produced.

Optional besteht im Übrigen die Möglichkeit, die Deck-Pressgutschichten 4`, 5' nicht aus herkömmlichen rieselfähigen Spänen, sondern aus einem fließfähigen Span-Flüssigkeitsgemisch 9 zu erzeugen. Beispielhaft ist eine solche Herstellung in Fig. 4 dargestellt. Die lediglich vereinfacht dargestellte Anlage zur Herstellung einer Werkstoffplatte 1 weist die bereits erwähnte Presse 8 und das Formband 7 auf, auf welchem die Pressgutmatte 1' erzeugt wird, sodass diese Pressgutmatte 1'unter Bildung der Holzwerkstoffplatte 1 in der Presse 8 unter Anwendung von Druck und Wärme verpresst wird. Zur Erzeugung der Pressgutmatte 1' weist die Anlage eine Formstation 10 auf, die einerseits Auftragsvorrichtungen 11 für die Kernschicht und andererseits Auftragsvorrichtungen 12 für die Deckschichten aufweist. Während die Auftragsvorrichtungen 11 für die Kernschicht als herkömmliche Streumaschinen bzw. Streuköpfe für das Aufbringen der Strands 3 ausgebildet sind, sind die Auftragsvorrichtungen 12 für die beiden Deckschichten in diesem Ausführungsbeispiel für den bereits erwähnten flüssigen Auftrag der Deckschichten bzw. für die Erzeugung des Span-Flüssigkeitsgemisches 9 ausgebildet. Es kann sich z. B. um Extrusionsvorrichtungen handeln, mit denen das Span-Flüssigkeitsgemisch 9 unter Bildung der jeweiligen Deck-Pressgutschicht 4`, 5' aufgebracht wird. So wird zunächst auf das Formband 7 die untere Deck-Pressgutschicht 5' als Span-Flüssigkeitsgemisch aufgebracht. Darauf werden herkömmlicher Weise die einzelnen Lagen 2a, 2b, 2c der Kern-Pressgutschicht 2' aufgestreut, und zwar mit den Auftragsvorrichtungen 11, wobei ein Streukopf 11 für die untere Kernlage und ein Streukopf 11 für die obere Kernlage und dazwischen zwei Streuköpfe 11 für die mittlere Kernlage angedeutet sind. Auf die aufgestreute Kern-Pressgutschicht 2` wird wiederum die obere Deck-Pressgutschicht 4' als Span-Flüssigkeitsgemisch aufgebracht, und zwar wiederum mit einer als Extrusionsvorrichtung ausgebildeten Auftragsvorrichtung 12.Optionally, it is also possible to produce the cover pressed material layers 4`, 5' not from conventional free-flowing chips, but from a flowable chip-liquid mixture 9. An example of such production is Fig.4 shown. The system for producing a material board 1, which is only shown in simplified form, has the already mentioned press 8 and the forming belt 7, on which the pressed material mat 1' is produced, so that this pressed material mat 1' is pressed in the press 8 using pressure and heat to form the wood-based panel 1. To produce the pressed material mat 1', the system has a forming station 10, which on the one hand has application devices 11 for the core layer and on the other hand application devices 12 for the cover layers. While the application devices 11 for the core layer are designed as conventional spreading machines or spreading heads for applying the strands 3, the application devices 12 for the two cover layers in this exemplary embodiment are designed for the already mentioned liquid application of the cover layers or for producing the chip-liquid mixture 9. It can e.g. B. extrusion devices with which the chip-liquid mixture 9 is applied to form the respective cover layer 4`, 5'. Firstly, the forming belt 7 is the lower cover pressed material layer 5' is applied as a chip-liquid mixture. The individual layers 2a, 2b, 2c of the core pressed material layer 2' are then sprinkled on in the conventional manner, using the application devices 11, with a spreading head 11 for the lower core layer and a spreading head 11 for the upper core layer and two spreading heads 11 for the middle core layer in between being indicated. The upper cover pressed material layer 4' is then applied as a chip-liquid mixture to the sprinkled core pressed material layer 2', using an application device 12 designed as an extrusion device.

Im Übrigen kann die in Fig. 4 lediglich angedeutete Anlage natürlich weitere, übliche Komponenten aufweisen, die in der Fig. 4 nicht dargestellt sind. So können zwischen der Formstation 10 und der Presse 8 z. B. Einrichtungen zur Bearbeitung der Pressgutmatte 1', eine Vorpresse und/oder Vorwärmeinrichtung, Vorrichtungen zur Detektion von Fremdkörpern und/oder eine Fehlschüttung angeordnet sein.Furthermore, the Fig.4 The merely indicated system will of course have other, usual components that are Fig.4 are not shown. For example, between the forming station 10 and the press 8, there can be arranged devices for processing the mat 1' to be pressed, a pre-press and/or pre-heating device, devices for detecting foreign bodies and/or a misfill device.

Claims (12)

  1. Composite material board, more particularly wood composite board (1) with at least one core layer (2) made of strands (3) and with cover layers (4, 5) made of chips (6), wherein the composite material board is formed through pressing a multiple-layer press material mat (1'), wherein the multiple-layer press material mat (1') is produced with at least core press material layer (2') of strands (3) and a lower and an upper cover press material layer (4', 5') of chips (6), characterised in that one or both cover layers (4, 5) are designed as non-full area cover layers in such a way that individual strands (3) at least partially extend through the cover layer (4, 5), forming interruptions in the cover layer (4, 5), as far as the board surface, wherein the lower cover press material layer (5') and the upper cover press material layer (4) are produced in such a way that during the pressing, initially full-area cover layers with continuous surfaces of cover layer chips (6) are formed, and then through surface machining of the cover layers the non-continuous cover layers (4, 5) are produced and individual strands (3) at least partially extend through the cover layers, forming interruptions in the cover layers, as far as the board surface and are thus visible.
  2. Composite material board according to claim 1, characterised in that the partial area of strands (3) projecting through the respective cover layer (4, 5) to the surface or visible on the surface, is at least 20% and preferably less than 95% of the entire surface of the board (1), preferably 40% to 90%.
  3. Composite material board according to claim 1 or 2, characterised in that arranged been the cover layers (4, 5) is at least one core layer (2) made of strands (3) that comprises several layers (2a, 2b, 2c), wherein preferably the strands (3) in the individual layers of the core layer (2) are each orientated, and particularly preferably in the individual layers of the core layer are orientated in different directions.
  4. Composite material board according to any one of claims 1 to 3, characterised in that the cover layers (4, 5) each have a weight per unit area of less than 1.5 kg/m2, e.g. less than 1.0 kg/m2.
  5. Composite material board according to any one of claims 1 to 4, characterised in that the proportion of the cover layers (4, 5) is in each case less than 10%, preferably less than 8% of the weight per unit area of the board (1).
  6. Composite material board according to any one of clams 1 to 5, characterised in that the two cover layers (4, 5) made of chips (6) have a different weight per unit area, wherein preferably the weight per unit area of a cover layer, e.g. the upper cover layer (4) is at least 10% greater that the weight per unit area of the other cover layer, e.g. the lower cover layer (5).
  7. Method of manufacturing a composite material board according to any one of claims 1 to 6, more particular a wood composite board (1), wherein a multiple-layer press material mat (1') with at least one core press material layer (2') made of strands (3) and a lower and an upper cover press material layer (4', 5') made of chips (6) is produced and
    wherein the multiple-layer press material mat (1') is pressed, forming the composite material board (1) with a core layer (2) and cover layers (4, 5) and
    wherein the surfaces of the cover players (4, 5) are machined after pressing,
    characterised in that the lower cover press material layer (5') and the upper cover press material layer (4') are produced in such a way that during the course of pressing, initially full-area cover layers with continuous surfaces of cover layer chips (6) are formed and then, through machining of the surfaces of the cover layers, the non-full area cover layers (4, 5) result, and individual strands (3) at least partially extend through the cover layers, forming interruptions in the cover layers, as far as the board surface and thus become visible.
  8. Method according to claim 7, characterised in the surfaces of the cover layers (4, 5) are ground after pressing so that non-full area cover layer (4, 5) are brought about through the grinding process.
  9. Method according to claim 7 or 8, characterised in that the core press material layer (2') is produced from scatterable strands (3) through scattering.
  10. Method according to any one of claims 7 to 9, characterised in that the cover press material layers (4', 5') are produced from scatterable chips (6) through scattering.
  11. Method according to any one of claims 7 to 9, characterised in that the cover press material layers (4', 5') are produced from a flowable chip-fluid mixture.
  12. Method according to claim 11, characterised in that the cover press material layers are produced from a flowable chip-fluid mixture through extrusion or through roller application.
EP20753340.7A 2019-08-08 2020-08-05 Material board and method for producing a material board Active EP4010158B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102019121471.8A DE102019121471A1 (en) 2019-08-08 2019-08-08 Material plate and method for producing a material plate
PCT/EP2020/072031 WO2021023782A1 (en) 2019-08-08 2020-08-05 Material board and method for producing a material board

Publications (3)

Publication Number Publication Date
EP4010158A1 EP4010158A1 (en) 2022-06-15
EP4010158B1 true EP4010158B1 (en) 2024-07-31
EP4010158C0 EP4010158C0 (en) 2024-07-31

Family

ID=71994508

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20753340.7A Active EP4010158B1 (en) 2019-08-08 2020-08-05 Material board and method for producing a material board

Country Status (6)

Country Link
US (1) US20220355507A1 (en)
EP (1) EP4010158B1 (en)
CN (1) CN114206569B (en)
CA (1) CA3150406A1 (en)
DE (1) DE102019121471A1 (en)
WO (1) WO2021023782A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220412084A1 (en) * 2021-06-24 2022-12-29 Louisiana-Pacific Corporation Pre-consolidated fines layer for improved engineered wood products
DE102022134608A1 (en) 2022-12-22 2024-06-27 Siempelkamp Maschinen- Und Anlagenbau Gmbh Material plate and method for producing a material plate
DE102022134621A1 (en) 2022-12-22 2024-06-27 Siempelkamp Maschinen- Und Anlagenbau Gmbh Method for producing particles for the production of a material plate and material plate

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4364984A (en) * 1981-01-23 1982-12-21 Bison-Werke, Bahre & Greten Gmbh & Co., Kg Surfaced oriented strand board
US5470631A (en) * 1990-04-03 1995-11-28 Masonite Corporation Flat oriented strand board-fiberboard composite structure and method of making the same
DE4434876B4 (en) * 1994-09-29 2004-09-16 Dieffenbacher Gmbh + Co. Kg Process and plant for the continuous production of a multilayer board
DE19913589A1 (en) * 1999-03-25 2000-09-28 Siempelkamp Gmbh & Co Wood-based panels, especially OSB panels
EP1136636B1 (en) * 2000-03-24 2004-06-02 Kronotec Ag Wood particle board, in particular a formwork panel
CN101332614A (en) * 2008-08-05 2008-12-31 云南永利发林业有限公司 Burnishing surface wood oriented structure chipboard and manufacture method and use thereof
CN103770187A (en) * 2012-10-19 2014-05-07 北京泛欧瑞得科技有限公司 Special type oriented strand board and manufacturing process thereof
CN109366679B (en) * 2013-06-17 2021-10-08 瓦林格创新股份有限公司 Method of manufacturing a wood-based board and such a wood-based board
CN203792464U (en) * 2014-04-22 2014-08-27 李波 Oriented wood chipboard with small particle surface suitable for veneer overlaying
PL3181314T3 (en) * 2015-12-16 2019-12-31 SWISS KRONO Tec AG Method for producing an osb with a smooth surface and an osb
DE102016110075A1 (en) * 2016-05-31 2017-11-30 Dieffenbacher GmbH Maschinen- und Anlagenbau Forming station and method for producing a multi-layer spreading material mat for pressing to material plates and a spreading material mat
DE102016110070A1 (en) * 2016-05-31 2017-11-30 Dieffenbacher GmbH Maschinen- und Anlagenbau Plant and method for producing a material plate
DE202017103956U1 (en) * 2017-07-03 2017-09-13 Kronospan Luxembourg S.A. OSB board and device for producing an OSB board
CN107498652B (en) * 2017-09-06 2020-10-23 南京林业大学 High-strength bamboo fiber curtain-OSB container bottom plate and manufacturing method thereof
CN108162122A (en) * 2017-12-08 2018-06-15 万华生态板业(信阳)有限公司 Oriented wood chipboard and orientation wood-based plate
CN108177227A (en) * 2017-12-14 2018-06-19 万华生态板业(信阳)有限公司 The manufacturing method of wood shavings fiber composite plate and wood shavings fiber composite plate

Also Published As

Publication number Publication date
WO2021023782A1 (en) 2021-02-11
CN114206569B (en) 2023-05-26
CA3150406A1 (en) 2021-02-11
EP4010158A1 (en) 2022-06-15
EP4010158C0 (en) 2024-07-31
CN114206569A (en) 2022-03-18
US20220355507A1 (en) 2022-11-10
DE102019121471A1 (en) 2021-02-11

Similar Documents

Publication Publication Date Title
EP4010158B1 (en) Material board and method for producing a material board
DE60012839T2 (en) Chipboard material and process for its production
EP2915640B1 (en) Method and apparatus for manufacturing an OSB panel
EP4010189B1 (en) Material board, method and system for producing a material board, and use of a material board
EP2148020B1 (en) Large format osb board with improved characteristics, in particular for the construction industry
DE60013647T2 (en) METHOD FOR GLUING AND DEVICE THEREFOR
EP1256426B1 (en) Device for spreading particles, in particular wooden chips, wooden fibers or the like on a coveyor belt
EP0573039B1 (en) Fibre mats containing a binding agent made from cellulosic and ligno-cellulosic fibres
EP2274176B1 (en) Derived timber plate provided with a high-gloss laminate coating, and method for producing such a derived timber plate
DE2052313C3 (en) Process for the production of single- or multilayer boards by pressing particles mixed with binder
EP3216574B1 (en) Method for manufacturing an osb
DE10024543A1 (en) Appliance and method of producing multi-layered board involve dispersing units, production of pressed material mat, edge-trimming appliances, sorters and conveyors.
DE10049050A1 (en) Oriented strand board with a shavings core and long chip outer layers, are obtained inexpensively with high bending modulus by using specified particle geometrical composition, core shavings content and pressure profile
WO2021023784A1 (en) Method for producing a material board
EP2078599B1 (en) Chipboard
DE2513764C3 (en) Method for producing a wood-based panel coated at least on one side, such as chipboard or the like
EP2977158A1 (en) Surface treatment of a workpiece surface
EP3181315B1 (en) Method for producing an osb with a smooth surface
WO2016180881A1 (en) Method and apparatus for spreading a nonwoven during the production of material panels, and a material panel
DE102007025063B4 (en) Process for producing a multilayer composite molding
DE102004049473B4 (en) Method and device for the production of wood-based panels, in particular fiberboard
DE102009000623A1 (en) Process for the production of chipboard
DE202015102415U1 (en) Device for spreading a fleece in the course of the production of material plates and a material plate
EP3290173B1 (en) Method for structuring the surface of a wooden panel and a surface-structured wooden panel prepared by means of this process
DE102008004154A1 (en) Method for producing a multilayer press plate

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20211221

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

INTG Intention to grant announced

Effective date: 20240312

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 502020008752

Country of ref document: DE

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: LANGUAGE OF EP DOCUMENT: GERMAN

U01 Request for unitary effect filed

Effective date: 20240808

U07 Unitary effect registered

Designated state(s): AT BE BG DE DK EE FI FR IT LT LU LV MT NL PT SE SI

Effective date: 20240826

U20 Renewal fee paid [unitary effect]

Year of fee payment: 5

Effective date: 20240827