Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
  • B27N—MANUFACTURE 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
  • B27N3/00—Manufacture of substantially flat articles, e.g. boards, from particles or fibres

Definitions

• the present invention relates to wood-based panels which have distributed throughout the wood-based panel effect particles, a process for their preparation and their use for the production of furnishings and interior fittings, especially as a floor covering.
• Wood-based materials are often used in furniture construction and interior design. HDF, MDF, OSB and chipboard are of particular interest because they offer an interesting alternative or a partial replacement for solid wood due to their comparatively low price and their partly similar properties. Wood materials are often used in the flooring sector. Industry and design are constantly seeking new answers to the increasingly complex demands placed on flooring products. The inventors have intensively studied materials and effects in combination with colored design elements in order to give the decorative wood flooring a new dimension. In addition, wood-based materials are produced from waste wood or wood waste and contribute to sustainable wood recycling.
• wood-based materials have advantages in their material properties over wood, for example, wood-based panels can be used for sound and thermal insulation and they are usually lighter and dimensionally stable than solid wood, this facilitates their handling and leads to weight savings in the products made from it.
• wood-based materials which have more advantageous physical properties, such as lower densities, improved tensile strength and moduli of elasticity, better thermal insulation and dimensional stability, higher sound absorption or higher resistance compared to previously known wood-based materials against water.
• the present object is achieved by a
• the wood-based panels according to the invention have an attractive surface, which is designed aesthetically pleasing by bmwteilchen.
• the fibers contained in the wood-based panel and / or chips which can be bleached or unbleached, dyed or uncoloured, and the effect particles used, for example, light-dark contrasts, color effects or glitter effects can be achieved which include the aesthetic design options greatly expand the wood-based panels according to the invention.
• the effect particles may have the physical properties of the wood-based panels e.g. in terms of density, water resistance, dimensional stability, tensile strength, modulus of elasticity, thermal insulation or sound absorption and impact / sound insulation.
• wood-based panels are panels which are produced by pressing wood fibers or chips in the presence of binders at elevated temperature.
• the term wood-based panels according to the present invention includes fiberboards made of wood fibers, with HDF and MDF panels being particularly preferred, as well as chipboard and OSB panels made of chips.
• Cellulose-containing fibers and chips of cellulose-containing materials are used for the wood-based panels according to the invention, which are also referred to below as base material.
• base material for the wood-based panels according to the invention it is possible in principle to use all span-shaped and fibrous materials to be obtained from plants. Usually, wood is used as raw material, but can be obtained from palm trees and bamboo and from annual plants such as bagasse or straw suitable cellulose-containing fibers. Another source is agricultural waste products.
• Preferred base materials are light wood species, spruce, pine, fir, birch or caoutchouc, but darker woods such as beech, eucalyptus, cherry, wild cherry, maple, oak, ash, nut can also be used.
• OSB Oriented Strand Board
• chips with a length of 40 to 200 mm are usually used.
• chipboard chips are usually used with a length of 0.2 to 15 mm.
• the length of the fibers for the production of HDF (High Density Fiber) plates and MDF (Medium Density Fiber) plates is usually 1 mm to 6 mm.
• the length of a particle, chip or fiber is understood to be the greatest extent of the particle, chip or fiber.
• the mean length is understood as the numerically weighted average. It can be determined, for example, by optical fiber analysis.
• the wood-based panels according to the invention contain at least 50% by weight, preferably at least 70% by weight, particularly preferably from 80 to 98% by weight and in particular from 85 to 95% by weight of dry cellulose-containing fibers and / or shavings, based on the total weight the wood material board.
• the wood-based panels according to the invention can be produced with or without a binder.
• they are made with binder.
• they contain at least 0.1 wt .-%, preferably 0.5 to 25 wt .-%, particularly preferably 2 to 15 wt .-% of binder based on the total weight of the wood material board.
• binders it is possible to use all binders known to the person skilled in the art for the production of wood-based materials.
• urea-formaldehyde resins include, for example, urea-formaldehyde resins, melamine-formaldehyde resins, phenol-formaldehyde resins, isocyanates (MDI), starch or starch derivatives, tannin, mixtures thereof and mineral binders such as gypsum or cement.
• MDI isocyanates
• the wood-based panels may contain other auxiliaries and additives such as hardeners, water repellents, formaldehyde scavengers, wood preservatives and fire retardants.
• the wood-based panels still contain moisture in addition to the ingredients listed above.
• the constituents contained in the wood-based panels according to the invention complement each other with water to 100 wt .-%.
• wood-based panels with effect particles which are HDF, MDF, OSB or chipboard panels; very particular preference is given to HDF and MDF panels.
• the wood-based panels according to the invention contain, in at least one outer layer, in addition to the fibers and / or shavings used as the basis, from 0.1 to 50% by weight, preferably from 1 to 30% by weight, particularly preferably from 5 to 25% by weight of effect particles, based on the total weight of the outer layer containing the effect particles.
• outer layers the two, the top and bottom of the plate forming layers are referred to.
• the effect particles located in the outer layer or layers are partly visible from the outside and determine the visual appearance of the wood-based panels according to the invention.
• the outer layers before an optional grinding process is or are at least 0.01 mm, preferably at least 1 mm and particularly preferably at least 3 mm thick.
• the thickness of the top and bottom is measured vertically in the direction of the center of the plate.
• the thickness of the outer layer corresponds to the thickness of the wood-based material panel, so that the effect particles are distributed throughout the wood-based panel.
• the wood-based panel according to the invention contains the effect particles in their entire thickness, this is advantageous during processing, since the edges also have effect particles and are not noticeable in comparison with the top and bottom sides.
• the wood-based panels according to the invention according to this embodiment behave similarly to solid wood also against injuries of the surfaces, since the wood-based panel has a continuous uniform structure. For this reason, minor surface damage can also be eliminated simply by re-surface treatment such as sanding and sealing.
• wood-based panels contain rgicteilchen. These are solid, particulate particles selected from inorganic and organic materials. They are to visually change the surfaces of the wood-based panels according to the invention in an aesthetically pleasing manner in comparison to the conventional panels of wood-based panels.
• the effect particles therefore differ according to the invention from the fibers and chips used as the base material by at least 5 wt .-% of the effect particles, based on the total weight of the effect particles in the dry state, in at least 2 dimensions greater than 1 mm in fiberboard (a) and in chipboard and OSB boards the effect particles are not selected from wood and wooden parts (b).
• At least 5% by weight of the effect particles are greater than 1 mm in at least 2 dimensions, preferably at least 10% by weight greater than 1 mm, particularly preferably at least 20 Wt .-% greater than 1 mm and more preferably at least 50 wt .-% greater than 1 mm.
• At least 5% by weight of the effect particles, based on the total weight of the effect particles in the dry state are larger than 2 mm, preferably at least 10% by weight, in at least 2 dimensions 2 mm, more preferably at least 20 wt .-% greater than 2 mm and particularly preferably at least 50 wt .-% greater than 2 mm.
• the particle dimensions are determined by sieving.
• the effect particles should improve the physical properties of the wood-based panels.
• the effect particles in the wood-based panels according to the invention distributed throughout the plate, a higher loading of the wood-based panels is possible with the effect particles, so that for example a part of the fibers / chips used in the wood-based panels can be replaced by materials with a lower specific density.
• an MDF board according to the invention which was produced with 11.6 wt .-% bark pieces, has a lower density than the analogously produced MDF board, which contained no bark pieces.
• the mechanical properties of the wood-based panels can be improved.
• the tread / sound and heat insulation properties of the wood-based panels can be improved. This is particularly advantageous when using the wood-based panels according to the invention as floor or wall panels.
• inorganic materials from which the effect particles can be selected according to the invention are, for example, mussel shells, glass fibers, calcined and uncalcined mica and pyrite.
• organic materials from which the effect particles can be selected according to the invention include e.g. renewable vegetable raw materials, animal products, plastics and products thereof.
• parts of annual and biennial plants, wood, wood fibers, bark, cork, leaves, flowers, wood shavings, hemp kenaf fiber, water hyacinths (stems), plant seeds, cereals, textile residues from plant fibers, cardboard and paper are among the vegetable renewable resources the animal products, in particular feathers, horn and hair, and among the plastics in particular plastic fibers, textile remnants of synthetic fibers, superabsorbents, packaging material, foil and plastic granules.
• the effect particles are not selected from wood or wood parts according to criterion (b).
• the wood parts in accordance with the present invention include bark pieces, wood chips, wood fibers, wood chips, twigs and the like.
• the effect particles according to criterion (b) are not selected from parts of renewable vegetable raw materials suitable for fiber or chip production.
• the effect particles according to criterion (b) are particularly preferably not selected from renewable vegetable raw materials, in particular the effect particles according to criterion (b) are selected from inorganic materials, animal products and plastics.
• the effect particles may be selected from the same material, but it is also possible to use mixtures of effect particles of two or more materials.
• the effect particles are preferably with a moisture content of 0 to 15 wt .-%, preferably from 0 to 5 wt. % Moisture, based on the dried effect particles used.
• the effect particles can be pretreated by separating off the fine fraction by means of suitable classification methods such as sieving or sifting, gluing, impregnation and hydrophobing.
• HDF and MDF plates preference is given to using effect particles which originate from a sieve fraction greater than 1 mm, preferably greater than 2 mm.
• HDF and MDF boards are produced with effect particles from vegetable raw materials, preferably with effect particles of bark, cork and wood chips. Also preferred are HDF and MDF boards with effect particles selected from plastic, paper, cotton, metal foils and their products. The effect particles of one kind but also two or more different ones can be selected.
• the fibers and / or chips used to produce the outer layer containing the effect particles are bleached as a base. This can, for example, according to the EP 1 899 427 respectively.
• At least one or both outer layers is colored. This can be done by coloring the fibers and / or shavings used to make the outer layer (s) by coloring the binder or by coloring binder and fibers and / or shavings.
• the coloring can, for example, according to the EP 1 556 196 be performed.
• the entire plate is colored through.
• Woodfree refers to paper made from bleached or unbleached pulp and containing at most 5% of lignified fibers. This pulp is a chemically produced pulp made of wood. The wood-free papers survive the temperatures of about 190 ° C when pressing the wood-based panels, without burning and without strong yellowing.
• the papers used can be equipped with, for example, pigments, white pigment preparations (for example BASF's Dispers White), binders and additives (eg optical brighteners) which protect the papers used as effect particles from yellowing continue to protect when pressing the wood-based panels prevailing conditions.
• the papers may be cut, torn, plucked or punched, single and heaped, added as flat leaflets or crumpled into balls or balls.
• the fibers and / or chips used to produce the outer layer containing the effect particles are bleached and, in addition, the outer layer is colored. Also preferred is an embodiment in which all the fibers and / or chips used as a basis for producing the wood-based panel are bleached and dyed.
• step A) of the abovementioned process according to the invention for producing the wood-based panels according to the invention the cellulose-containing raw materials are comminuted or machined in order to recover fibers and shavings.
• the exact method depends on the raw material used and the desired wood material.
• the cellulose-containing raw materials are first comminuted and optionally washed. This may possibly be followed by a pretreatment. For example, wood is first chopped up, washed and the water-moist pieces of wood (wood chips) preheated first.
• the comminuted, cellulosic raw materials are pretreated in a so-called digester. Usually, this is carried out at a pressure of 2 to 10 bar and a temperature of 100 to 200 ° C. The exact temperatures and pressures depend on the raw materials used. Lower annual temperatures are usually lower enough for digestion of annual plants than for the digestion of multi-annual plants such as wood.
• the optionally pretreated, comminuted, cellulose-containing raw materials are transferred to a so-called refiner and ground there to form fibers.
• a refiner is usually a grinding unit with rotating and possibly fixed knives / discs for grinding fibrous materials and preferably consists of two radially-provided with metal discs which are close to each other. One of these two discs can move, but both can rotate in opposite directions. Usually, the refiner works with overpressure.
• the grinding of optionally pretreated, comminuted, cellulose-containing raw materials can also be carried out in other devices suitable for this purpose. Subsequently, the fibers are carried out of the refiner.
• wood chips are first produced. These may be residual wood from the forestry, from the sawmill industry or from unladen used wood.
• the shavings can be obtained as shavings from chippers, as chipping chips from reciprocating or toothed disc mills or as grinding chips from mills or refiners. Waste chips such as milling or wood shavings can also be used.
• step B) of the method according to the invention the fibers and / or chips are dried, sifted and glued.
• the different process steps can be carried out in different order and number.
• the sifting of the fibers and / or chips serves to sort the fibers and / or chips according to size.
• the dried glued or non-glued fibers and / or chips can be spotted. This can be done for example in a cyclone or an air classifier.
• the fibers are usually blown out of the refiner by a so-called blowline.
• a blowline is usually understood as a blow line through which the fibers are carried out by the pressure prevailing in the digester and the refiner.
• the fibers in the refiner or in the course of the fibers may be bleached from the refiner by the addition of a bleach-containing bleach composition.
• the fibers can be bleached reductively or oxidatively.
• reducing sulfur compounds such as dithionites, disulfites, sulfites or sulfur dioxide, sulfinic acids and their salts, in particular the alkali metal salts and especially the sodium salts and hydroxycarboxylic acids such as citric acid and malic acid are suitable.
• the fibers originating from the refiner are still glued moist in the blowline.
• the fibers can also be dried first and then glued in mixers.
• Another possible method for gluing is the so-called dry gluing.
• the dried fibers are sprayed with glue. If the wood fibers are glued in the blowline, they then pass through a dryer in which they are dried to moistures of 7 to 15 wt .-%.
• at least one sorting process follows the size of the fibers at the gluing and the drying.
• chips for chipboard and OSB boards are first dried, optionally sorted by size and glued in mixers or by dry gluing with the binder.
• step C) the fibers and / or chips are scattered into mats.
• step D) the mats are pressed into wood-based panels.
• the mats are cold precompressed without heat in a pre-press. That concludes the hot pressing, in which the mats are pressed in heated presses at temperatures of 150 to 240 ° C and pressures of 10 to 100 bar to plates.
• the usual finishing of the wood-based panels takes place, i. the seams of the panels are capped, and after cooling the panels, the surfaces can be sanded.
• the surfaces can also be finished with other coatings such as colorless paints or overlays.
• the effect particles are added to the fibers and / or chips after step A). This ensures that the effect particles are subsequently contained in the wood material in the selected shape and length or length distribution. If the effect particles were added to the cellulose-containing raw materials prior to step A), they would be subjected to the same digestion and comminution processes as the fibers or chips. On the one hand, this would not lead to the desired decorative effect on the surfaces or in the panels or, under certain circumstances, would not produce the desired improvements in physical or mechanical properties and, on the other hand, might damage the equipment for breaking up the cellulosic raw materials, since these are usually not are designed for inorganic raw materials.
• the effect particles can be added in the blowline, ie in step B) are added. In this case, a good gluing of the bmwteilchen is guaranteed.
• the effect particles in step B) are added to the fibers and / or chips.
• the addition of the effect particles at the end of the blowline or at the beginning of the dryer has the advantage that the effect particles can be glued in situ, hydrophobized and / or provided with further auxiliaries, such as a chemical crosslinker, etc. In the dryer, they can then be dewatered to the desired moisture content.
• the addition at the end of the blowline or at the beginning of the dryer can be carried out simply by means of a rotary valve (sealing against the pressure prevailing in the blowline or the dryer).
• Step B) offers further, particularly simple possibilities of integrating the addition of the effect particles into existing processes for the production of wood-based panels and at the same time ensuring the most uniform possible distribution of the effect particles in the wood-based panels according to the invention.
• One of these possibilities is the addition of the effect particles after gluing and drying of the fibers and / or shavings on the sifter belt, with which the fibers and / or chips are transported from the dryer to the classifier (for example air classifier).
• the classifier for example air classifier
• Other possibilities are the addition of the effect particles to the fibers and / or chips on the fiber bunker band with which the spotted, i. sized fibers and / or chips are added to the fiber bins and added to the spreader which spreads the fibers and / or chips into mats.
• the effect particles can be added simply by belt conveyance, in addition, a uniform mixing of the fibers and / or chips with the effect particles and thus obtained in the finished wood-based panel at these points.
• the effect particles used in this case can be glued, hydrophobized and / or provided with further aids such as chemical crosslinkers.
• the equipment with a chemical crosslinker or the gluing of the effect particles leads to better mechanical / physical properties of the wood-based panels according to the invention.
• the effect particles can be pretreated, dried or moistened independently of the fibers and / or chips so that they have a suitable moisture content of 0 to 15% by weight. Moisture, based on the dried effect particles included. Different drying properties of the fibers or shavings and the effect particles with co-drying, which may be caused for example by different particle sizes or moisture content, are avoided.
• the effect particles preferably contain no more moisture than the fibers and / or chips used as the base.
• the effect particles after step B), ie after drying, screening and gluing of the fibers and / or chips with the binder are added to these.
• the effect particles can be dried or moistened independently of the fibers and / or chips so that they contain a suitable moisture content of 0 to 15% by weight of moisture, based on the dried effect particles.
• the effect particles preferably contain no more moisture than the fibers and / or chips used as the base.
• the adjustment of the moisture of the effect particles and the fibers and / or chips is extremely important for the hot pressing process, since the moisture contained serves as a heat transfer medium, which brings the heat of reaction required for the reaction of the binder in the plate.
• a homogeneous distribution of water in the mat to be pressed for the quality of the finished wood material is very important, since locally high water concentrations can lead to locally increased vapor development and resulting inhomogeneities in the finished plate. These steam bursts can even be so severe that they damage the press plates.
• the effect particles can be sprinkled onto the fiber and / or chip mat after step C) and before the hot pressing in step D). This can be done before or after the cold pre-compression.
• This embodiment of the present invention has the advantage that existing plants for the production of wood-based materials can be relatively easily retrofitted.
• the effect particles are sprinkled as a thin layer or in the form of a mixture of glued fibers and / or chips and bmwteilchen each as a layer on the top and / or bottom of the wood-based panel, the middle layer remains free depending on the thickness of the scattered layer.
• the scattered effect particles are incorporated according to a further embodiment of the invention in the fiber or chip mat, for example with a rake or a rake.
• the effect particles are not glued together with the chips and / or fibers, according to a preferred embodiment of the invention, the effect particles are optionally additionally glued and / or reinforced by an impregnation, for example with a chemical crosslinker.
• chemical crosslinkers are used for example in the DE 102006019819 described and offered under the brand Belmadur®.
• the wood-based panels according to the invention with effect particles have an attractive, aesthetically pleasing surface, so that they can be used in many ways for decorative purposes.
• they have increased resistance to moisture, higher dimensional stability, a lower density, better thermal insulation or better sound absorption.
• the present invention also relates to wood-based panels with the features described above, which can be produced by the method according to the invention.
• Another object of the present invention is the use of the wood-based panels described above for the production of home furnishings and interiors and the furnishings and interior fittings containing the wood-based panels described above.
• the furnishings are, for example, furniture and doors, in the interior fittings are particularly wall and floor panels to call, with the wood-based panels according to the invention are particularly well suited as floor coverings, especially the inventively preferred wood-based panels in which distributes the effect particles throughout the plate available.
• the main component of the solid flooring is shredded or chipped wood, which is enriched during the usual manufacturing process of the wood-based panels with natural effect substances. Due to the uniform distribution of the effect particles in the entire wood-based panel floor coverings from the wood-based panels according to the invention as well as floor coverings made of solid wood can be sanded several times and re-sealed.
• the perforator value according to EN 120 was determined for the two MDF boards from Example 1. This value is a measure of the outgassing of formaldehyde. The measured values are shown in Table 2. Table 2 MDF with bark (according to the invention) MDF without bark (comparison) humidity 3.9% by weight 4% by weight mg formaldehyde / 100 g atro sample 1.8 7 mg of formaldehyde / 100 g dry sample, taking into account 6.5% moisture. 2.4 9.2

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• 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)

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• 2008
  • 2008-11-28 DE DE102008059527A patent/DE102008059527A1/de not_active Ceased
• 2009
  • 2009-11-26 EP EP09177167A patent/EP2191949A3/fr not_active Withdrawn

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