EP1190825A2 - Thin-walled three-dimensional molded semi-finished or finished article - Google Patents

Abstract

Thin-walled, 3-dimensionally formed semi-finished products or finished parts, e.g. panels for furniture and doors, are obtained by hot press-moulding a mixture of wood and/or wood fibre and/or plant fibre particles with an average fibre length and thickness of 1.5-20 mm and 0.05-1.0 mm respectively plus 2-8 wt.% liquid, heat-reactive binder. Thin-walled 3-dimensionally formed semi-finished products or finished parts (I) for use as outer panels for furniture and in the production of doors etc., especially as highly profiled panels for shaped inner or outer doors. These products comprise a coherent mixture of wood and/or wood fibre material and/or plant fibre particles with an average fibre length and average thickness of 1.5-20 mm and 0.05-1.0 mm respectively plus 2-8 wt.% liquid, heat-reactive binder, obtained by precompression followed by forming under heat and pressure and having at least one outer surface coated with a thin plastic film or biodegradable varnish. Independent claims are also included for: (a) products as described above in which the wood/plant fibre particles comprise 75-95 wt.% thin fibres with an average length of 1.5-20 mm and an average thickness of 0.05-1.0 mm and 5-25 wt.% essentially cubic or approximately spherical particles in the size range 0.005-1.0 mm; (b) a method for the production of (I) by forming the above mixtures in a permanent mould at 20-45 bar (depending on the product) and 140-180 degrees C; (c) a method for the production of (I) in which the fibre particles (or the thin fibre component) consist(s) of various lignocellulose fibres; and (d) a method for the production of (I) in which the moulding top and the interlayer are pressed together, especially around the edge band of a heated press, and a reduced pressure is generated between moulding top, edge band and interlayer by means of hole(s) in the edge band.

Description

The invention relates to a thin-walled, three-dimensionally shaped semi-finished or finished part for use as a cover plate (molded deck) in industrial door production, in furniture construction and in comparable areas, especially for use in strongly profiled sheets of profile doors for indoor and outdoor use and a process for their manufacture.

Known door leaves of wooden doors consist of wood-based panels or a Solid wood frame that surrounds the insert and holds cover plates on both sides. The Inlay is made of heat or sound-absorbing materials or panels (e.g. Chipboard) formed. Plywood, veneer, wood fiber or are used as cover plates Chipboard or two cross-laminated veneer layers.

For the production of strongly profiled door leaves, industrially manufactured doors are CNC-controlled Machining machines Grooves, profiles or other design elements milled from solid wood, chipboard or MDF. An alternative way consists in the subsequent application of design elements such as profile strips, Cassettes, etc. The decorative design elements with the cover plate screwed, dowelled or glued flush.

Both methods have significant shortcomings. Subsequent machining complete door leaf caused by the attainable working speeds of the used end mill or end mill significant manufacturing costs and also extends the Lead time of the products. In addition, correspondingly large milling devices must be used or machining centers for complete machining of the large door leaves be used.

During the subsequent assembly or joining of form-forming elements, the In contrast, a higher installation effort. Also, the usually glued positioned design elements and until the setting or hardening of the Adhesive are kept in this forced position. Taking into account more economical Minimum numbers of items must therefore be redundantly provided for several devices in order to be able to realize the technologically related holding and setting times.

In addition, from DE 199 56 765 A1 mold decks are known which consist of a mixture Wood and / or wood material particles and a heat-reactive, powdery binder, preferably a phenolic resin. The grain size of the quasi cubic to spherical wood or wood material particles is between 0.1 mm and 0.6 mm, the The optimum proportion of the powdery, heat-reactive binder in the mixture 12% to 14%. The disadvantage of this is the high proportion of the binder that is required to adequate wetting of the free surface of the contacting spherical Realize wood or wood material particles. The bad is also a disadvantage Environmental compatibility of the phenolic resin binders.

Another decisive disadvantage is the limited bending strength of the mold decks due to the size and shape of the wood or wood material particles used. Thereby can have minimum wall thicknesses of 6 mm to 8 mm in self-supporting areas of the mold decks not fall below. In order to achieve the necessary bending strength with extremely thin walls of the form deck are realized in the adjacent regions with constructive Means stiffening elements, e.g. B. in the form of webs.

The object of the invention is to eliminate the disadvantages of the known prior art and a highly resilient, thin-walled, three-dimensionally shaped semi-finished or finished part for use as a cover plate (molded deck) in door production, in furniture construction, and in comparable areas, to propose that industrially producible in large numbers is and allows a strongly profiled design of the mold decks, as they are in particular handcrafted solid wood doors is known. The semi-finished or finished parts should can also be stored to save space.

From an ecological point of view, the manufacture of the semi-finished or finished part Materials are used, their use in terms of health, environmental protection and are safe from a safety point of view, which can be recycled and in particular as Waste products in woodworking and processing arise. In addition, there should be a procedure be proposed with the heavily profiled doors manufactured economically profitable can be.

According to the invention the object is achieved by the features of main claim 1 and of the secondary claim 2. Further developments of the invention are the subject of back-related subclaims.

A prefabricated part according to the invention, such as a door leaf, consists of a frame or edge band made of wood, wood-based materials, plastic and / or metal. The frame as a support structure takes the intermediate layers and the outer, thin-walled, three-dimensional molded mold decks. The form decks are glued to the body with the Frame or edge band and / or the intermediate layers connected.

The mold decks are made from a mixture of wood, wood-based material and / or fiber particles annual or suitable perennial plants and a liquid, thermosetting binder, preferably an isocyanate.

The wood, wood material or fiber particles used have an elongated, fiber-like Form on, with the average length of the fibers 1.5 mm to 20 mm and the average thickness Is 0.05 mm to 1.0 mm. The proportion of the liquid, heat-reactive binder on Mixture is about 2 to 6 mass%. The cohesion of the mixture is ensured by Pre-compression and subsequent forming with the application of pressure and heat. It was surprisingly found that the shaped semi-finished and finished parts were higher Strength than known form decks, which consist exclusively of spherical wood particles can be manufactured with a nominal diameter of 0.1 mm to 0.6 mm. moreover The new form decks are characterized by better resistance to high Humidity.

In an alternative form, in addition to elongated, fibrous wood, wood-based material or fiber particles with an average length of the fibers 1.5 mm to 20 mm and an average thickness of 0.05 mm to 1.0 mm for the production of the semi-finished or finished parts in addition, essentially cubically shaped or spherical wood, wood material or fiber particles with a fraction size between 0.005 mm and 1.0 mm are used. The proportion of these fine particles in the total mass of the particles is between 5 M% and 25 M%.
The proportion of the liquid, heat-reactive binder in the mixture is about 2 to 8 percent by mass. The cohesion of the mixture is created by pre-compression and subsequent forming with the application of pressure and heat.
The first-time use of a mixture of elongated, fibrous particles and the cubic or roughly spherical fine particles in the spaces between the fibers and on the outer surface of the semi-finished or finished part create a new hybrid structure that further increases the strength of the product causes.
Introducing the very fine particles into the near-surface zone of the particle mixture also creates a quasi-closed pore structure after pressing. This significantly reduces the surface roughness of the pressed semi-finished or finished part, which leads to a significant improvement in quality. This means that time-consuming post-processing (filling, sanding) can be dispensed with or, alternatively, cheaper films can be used for the surface lamination of the mold decks produced in this way.

The different constituents of the mixture (long-fiber particles and approximately cubic shaped fine particles) by joint defibrillation, e.g. B. from Wood chips and straw are produced so that there is no separate, downstream one Mixing process needs.

At least one top surface of the shaped semi-finished or finished part is made by foiling with a thin-walled plastic film or a biodegradable paint system coated.

In addition to fulfilling aesthetic requirements, the film preferably used serves a protection of the door wing from mechanical stress and penetrating Moisture and also allows easier cleaning of the surface, in particular heavily used doors in public buildings, offices, etc. In addition, the 0.1 mm up to 0.5 mm thick film the optical conclusion of the molded part below. Thereby can wood or wood material particles or mixtures thereof to produce the Molding are used, which are made of different starting materials, eg. B. chips or chip fragments of ecologically prepared chipboard, as the outer one Foil laminates the surface of the mold deck.

On the other hand, the film, made of polyolefins, polypropylene or polyvinylchloride, which is elastic and easy to form when heated, allows uniform application to the surface of the molded part even in the case of strongly structured surfaces when processed in known 3D vacuum presses.
The use of structured, colored or decorated foils also gives the product higher aesthetic performance properties.

In contrast to the alternatively possible coating of the surface of the molded parts by means of water-soluble paints in the immersion or spray process, the lamination of a film is characterized by a higher work productivity. This eliminates the need for multiple sanding of the strongly profiled surfaces of the mold deck when applying a paint system.
In addition, there are no technology-related auxiliary processes and the use of complex technology that is essential for conventional coloring (use of paint spray booths, technology-related holding times for drying and drying the paint system, intermediate storage until the paint cures / sets).

Another advantage of using a film made of P0, PP or PVC as a surface finish of the molded part is that the necessary adhesive is laminated onto the film can. A hot melt adhesive is preferably used as the adhesive. The one so prepared The film can be rolled up, can be stored almost indefinitely when glued and is easy to use to process. Another major advantage is that the glueing in the Usually highly structured surface of the molded part can be omitted.

Alternatively, it is also possible to spray the hot melt adhesive directly onto the molded part. Freely programmable industrial robots or manipulators are advantageously used for this, so that any sequence of different products can be processed. The amount of adhesive to be applied can also be dosed individually by spraying the strongly profiled zones of the mold decks in several steps.
The 3-D films made of polypropylene or PVC, which are preferably used, have the grain of a real wood veneer in a likewise preferred form.
In addition to the technological advantages of using foils for finishing the surface of the mold decks (quick processability, good availability, no technological auxiliary times for drying / setting, such as when using coating systems), the foils are also characterized by their high abrasion resistance. In addition to the good resistance to temperature fluctuations and weather influences, the films used guarantee a long service life and functionality of the doors manufactured in this way. Due to the design possibilities, these industrially manufactured doors also meet high aesthetic requirements with reduced manufacturing costs.

The main advantages of the semi-finished or finished parts formed in this way are one higher compressive and bending tensile strength. This results in addition to the one used Mixture of materials from the pre-compression of the randomly arranged material particles in the Fiber fleece and the subsequent, repeated compression and original shaping of the Starting material.

Due to the better strength properties, the mechanical strength can be the same lower wall thicknesses of the mold decks up to about 3 mm can be realized. At the same time Use of the fiber-binder mixture reduced by up to 50%.

The fibrous wood particles used with preference are advantageously produced from wood chips from untreated sawmill residual wood or from thinning wood. The chips or chips are first broken down in a water bath, then defibrated in a defibrator while adding water to an average length of the wood fibers of 1.5 mm to 20 mm and an average thickness of 0.05 mm to 1.0 mm and then dried. The average size of the wood fiber particles is set by adjusting the grinding gap width and / or by changing the length of time in the defibrator.
During drying, the moisture content of the wood fiber particles is reduced to 6% to 10% for the subsequent primary shaping.

The dried, loosened and adjusted to the given residual moisture content wood fiber particles are then wetted with the liquid binder and pre-compressed to an even loose fleece with an average thickness of about 40 mm to 60 mm.
The processing of fibers of annual or suitable perennial plants takes place according to known technologies. After digestion of the fiber, it is brought to the required residual moisture content, then mixed with binder and processed into a fleece.

The pre-compacted fleece made of wood or vegetable fibers is cut by a trimming cut brought the required output size and then in one or more parts, heatable press die formed into a semi-finished product or a finished mold deck.

By using a fleece made of elongated, interwoven or matted fiber particles in combination with a liquid, thermosetting binder, that easily onto the surface and into the open cavities between the touching Wood particles can penetrate, the possibility is created at sufficiently high Strength to manufacture extremely thin-walled molded parts. Thanks to the surface wetting of the elongated wood particles with the binding agent get through during the forming process the heat input to fix the randomly matted wood particles.

They are semi-finished products or shaped decks with an average wall thickness of 3 mm to 7 mm produced. Due to the special structure of the starting material in connection with the subsequent forming under pressure and temperature there is also the possibility of Production of thin-walled, shell-shaped semi-finished products or molded parts with uniform Wall thickness. This makes it possible to manufacture semi-finished products or molded parts with the same design visible top surface and the underlying surface. Thus, the Molded parts without complex technological aids and conveyors (shelves, Devices) are stacked on top of each other and transported.

In addition to the use of natural wood chips or shavings, which can be obtained as a low-cost waste product from sawmills or other wood processing companies, there is the possibility of using chips made from recyclable wood, e.g. B. old wood or used wood materials, such as. B. chipboard as a raw material.
With known technologies, chipboard can be mechanically shredded or its components can be broken down in fluid systems. After the disposal of any pollutants (e.g. binding of formaldehyde with known formaldehyde scavengers), the chips are brought to the desired nominal size and the optimum residual moisture is set.

All heat-reactive binders or adhesives can be used as binders, which are suitable for the production of wood-based materials. A liquid PMDI binder is preferred used. This ensures an even wetting of the surface of the wood particles without signs of separation and at the same time good sliding behavior of the Wood particles in the die during the forming process.

Due to the good wetting of the surface of the wood particles, the proportion of binding agent is only about 2% to 6%, based on the mass of the wood particle-binder mixture.

Thanks to the good flow properties of the wood particle-binder mixture during pressing not only can heavily profiled molded decks be produced. That is also advantageous Possibility to reduce the average wall thickness of the mold decks up to 3.0 mm. In order to the shell-like molded decks thus produced have mechanical properties Lightweight element.

Another advantage is that due to the good plasticity and the Creep properties of the wood particle-binder mixture constant wall thickness can be produced within the mold deck without the Strength properties of the mold deck are adversely affected.

The thin-walled molded decks are used in particular as a decorative exterior finish Doors, furniture or decorative items are used. Because of the good flow properties The wood particle-binder mixture can also be used for large door decks with an average wall thickness between 3 mm and 6 mm, the outer dimensions up to 2200 x 1000 mm.

The preferred use of the form decks in the production of style doors for the interior or The outdoor area is described below as an example:

Figur 1 zeigt in einer stark stilisierten Darstellung ein Türblatt einer einfachen Zimmertür, dessen sichtbare Oberfläche von einem durchgehenden Formdeck 1 gebildet wird.

Figur 2 zeigt in einer Seitenansicht den stark strukturierten Konturenverlauf des extrem dünnwandigen Formdecks (1) zwischen Rand (2) und Mittelteil (3). Aufgrund der besonderen Eigenschaften des verwendeten Faser-Bindemittel-Gemisches und wegen der Umform-Urform-Technologie beim Vorverdichten des Vlies und dem nachfolgenden Formgebungsprozess können auch größere Versetzungen der einzelnen Bereiche des Formdecks gegenüber der Längsachse (X) ohne auftretende Schwindungen oder Rissbildungen gefertigt werden.

Figur 3 zeigt drei weitere, beispielhafte Formen eines Türblattes, die unter Verwendung mehrerer Formdecks gefertigt werden.
Form A zeigt ein Türblatt mit Einfachfalz, dessen sichtbare Fläche aus zwei eingesetzten Kasettendecks besteht. Die Formen B und C zeigen aufwendig gestaltete Spezialtüren mit Doppel- und Dreifachfalz für die Verwendung im Innen- bzw. Außenbereich.

Figur 4 zeigt eine stilisierte Schnittdarstellung einer Einfachfalztür mit verbesserten Schallschutzeigenschaften.
Als Mittellage 4 wird eine 10 mm dicke Spanplatte verwendet. In der Randzone wird das Türblatt durch zwei angrenzende, 16 mm dicke Spanplatten 5 ausgesteift. Im mittleren Bereich des Türblattes sind zwei 8 mm dicke MDF-Spanplatten 7 durch Tackern mit der Mittellage 4 verbunden. Den seitlichen Abschluss des Türblattes bildet ein Umleimer 8 aus astfreiem Kantholz. Die beiden außenliegenden, schalenförmigen Formdecks 1 weisen im Profilierungsbereich 6 kehlenförmige Ausnehmungen auf.
Die Verbindung der beiden Formdecks mit der darunter liegenden Mittellage 4 bzw. den Span- und MDF-Platten erfolgt durch vollflächiges Verkleben mit bekannten Klebstoffsystemen.
Den äußeren Abschluss des Türblattes bildet eine Polypropylenfolie 9, die vollflächig die gesamte Oberfläche des Türblattes überzieht.

Fig. 5 zeigt in einer stilisierten Darstellung einen Querschnitt durch eine Dreifach-Falztür. Diese massive Tür entspricht höchsten Anforderungen hinsichtlich Einbruchshemmung, Schallschutz und Wärmedämmung. Die Dreifach-Falztür besteht aus einer Füllung mit insgesamt drei Zwischenlagen 10 aus jeweils 16 mm dicker Spanplatte. Daran schließen sich im unteren Randbereich zwei 16 mm dicke Spanplatten 11 an. Im Mittelbereich des Türblattes werden an dieser Stelle zwei 8 mm dicke MDF-Spanplatten 12 zur verbesserten Schallimmission eingesetzt. Aus Schallschutzgründen wird der Sandwich-Verbund beidseitig durch eine Aluminiumsperrfolie 13 abgeschlossen. Die außenliegenden profilierten Formdecks weisen auf ihrer Oberfläche eine Dekorfolie 14 auf. Den seitlichen Abschluss des Türblatts bildet ein Rahmenholz 15 mit integrierter Silikondichtung 16.
Die Verbindung der drei Zwischenlagen untereinander erfolgt durch punktweise Verklebung mit bekannten Harnstoff- oder Weißleimen, durch Klammern oder Tackern. Damit werden bessere akustische Eigenschaften des Türblattes realisiert. So können durch die partielle Verklebung ausreichend Schubspannungen übertragen werden, die bei der Bewegung der Tür zwangsläufig auftreten und bei einer vollflächigen Verklebung zu einer verstärkten Geräuschbildung führen würden. Nachdem das Türblatt als Sandwichelement vorbereitet ist, erfolgt die abschließende Finishbearbeitung durch Kaschieren der Oberfläche mit einer 0,3 mm starken Polypropylen-Dekorfolie. Das Aufbringen der PP-Folie auf die beleimte Oberfläche der Formdecks erfolgt auf bekannten Membranpressen. Die PP-Folie überzieht dabei vollflächig die gesamte Oberfläche des Türblattes. Das Folieren des Falzbereiches erfolgt auf einer gesonderten Presse. Durch die geschlossene Folierung bis in den Falzbereich wird ein Eindringen von Feuchtigkeit wirksam verhindert.

Figur 6 zeigt ebenfalls in einer Seitenansicht zwei symmetrisch gestaltete Formdecks 1, die spiegelbildlich zueinander angeordnet sind. Dabei werden die formgestalterischen Möglichkeiten sichtbar, die sich aus der hohen Bildsamkeit des verwendeten Ausgangsmaterials und der verwendeten Fertigungstechnologie ergeben.

Figur 7 verdeutlicht die vorteilhafte Lagerung der dünnwandigen Formdecks 1 im Paket. Die Formdecks sind so gestaltet, dass im Paket ein vollflächiges Aufeinanderliegen der Teile garantiert ist und ein etwaiges Verziehen während der Abkühlphase der frisch gepressten Formdecks sicher vermieden wird. Die Lagerung im Paket ermöglicht vorteilhaft eine gleichmäßige Konditionierung der Formdecks. So kann das Wasser, das während des Durchlaufens des Abkühlbades nach dem Pressen in die oberflächennahen Zonen des Decks eindiffundiert ist, gleichmäßig bis ins Innere des Formdecks kriechen.
Die geometrisch bedingt dünneren Profilbereiche des Formdecks erhalten durch die Realisierung eines größeren Umformgrades beim Pressen eine höhere Festigkeit. Die erhöhte mechanische Belastbarkeit der ungestützten, profilierten Bereiche des Formdecks wirkt sich zudem positiv beim nachfolgenden Pressbeschichten aus.
Durch diese besondere geometrische Gestaltung der Formdecks entfällt die flächenintensive Zwischenlagerung in Einzelablagen oder Hochregalen. Aufgrund der hohen Biegfestigkeit können die Pakete ohne konstruktiv angepasste Traversen mittels Hebezeugen transportiert werden.

Figur 8 zeigt in drei Phasen das Verfilzen und Komprimieren der Fasern:

Abbildung A zeigt die aufgelockerten Fasern, die gleichmäßig mit Bindemittel besprüht werden. Das zunächst noch unverdichtete Faservlies weist dabei eine mittlere Dicke von etwa 400 mm bis 600 mm auf.

Abbildung B zeigt das Faservlies nach dem Vorverdichten in einer Presse auf eine mittlere Vliesdicke von 40 mm bis 60 mm.

Abbildung C zeigt in stark stilisierter Darstellung das urgeformte Halbzeug oder Fertigteil mit einer konstanten Wanddicke von 4,0 mm.

Figur 9 zeigt beispielhaft einen technologischen Durchlaufplan für die Fertigung von Formdecks, beginnend mit der Auflockerung der angelieferten Rohfaserstoffe. Nach einer Zwischenlagerung der Faserstoffe, die lediglich zur Kompensation von Störungen bei der Rohstofflieferung dient, werden Verunreinigungen entfernt.

The decks are carcass-glued to the door blank in an unheated press with brief pressure and when using hot glue with the edging made of wood or MDF material. For this purpose, the first deck is placed on the processing table with the good side down and wetted with hot glue on the inside using the spray or pouring process. Then the edge frame as well as the individual parts of the intermediate or middle layer are inserted mechanically or by hand onto this deck. At the same time, the second deck is glued on the inside in a separate operation, turned over and placed with the good side up on the intermediate layer in the correct position.
This blank, which has now been completely folded but not yet joined, is fed to the press and pressed. After a short time in the press and the adhesive setting during this time, the finished blank is removed and fed to the further processing processes of formatting, rebating and foiling.

FIG. 1 shows in a highly stylized representation a door leaf of a simple room door, the visible surface of which is formed by a continuous molded deck 1.

Figure 2 shows a side view of the highly structured contour of the extremely thin-walled shaped deck (1) between the edge (2) and the central part (3). Due to the special properties of the fiber-binder mixture used and because of the forming-primary technology during the pre-compression of the fleece and the subsequent shaping process, larger dislocations of the individual areas of the molding deck with respect to the longitudinal axis (X) can also be produced without any shrinkage or crack formation occurring.

FIG. 3 shows three further, exemplary shapes of a door leaf which are manufactured using a plurality of molding decks.
Form A shows a door leaf with a single rebate, the visible surface of which consists of two inserted cassette decks. Forms B and C show elaborately designed special doors with double and triple folds for use indoors and outdoors.

Figure 4 shows a stylized sectional view of a single folding door with improved sound insulation properties.
A 10 mm thick chipboard is used as the middle layer 4. In the edge zone, the door leaf is stiffened by two adjacent, 16 mm thick chipboard 5. In the central area of the door leaf, two 8 mm thick MDF particle boards 7 are connected to the central layer 4 by stapling. The edge of the door leaf forms a border 8 made of knot-free squared timber. The two outer, shell-shaped molded decks 1 have 6 fillet-shaped recesses in the profiling area.
The two form decks are connected to the underlying middle layer 4 or the chipboard and MDF boards by means of full-surface gluing with known adhesive systems.
The outer end of the door leaf is formed by a polypropylene film 9, which covers the entire surface of the door leaf.

Fig. 5 shows in a stylized representation a cross section through a triple folding door. This massive door meets the highest requirements in terms of burglar resistance, sound insulation and thermal insulation. The triple folding door consists of a panel with a total of three intermediate layers 10 made of 16 mm thick chipboard. This is followed by two 16 mm thick chipboard 11 in the lower edge area. In the middle area of the door leaf, two 8 mm thick MDF chipboards 12 are used at this point for improved sound immissions. For soundproofing reasons, the sandwich composite is closed on both sides by an aluminum barrier film 13. The outer profiled molded decks have a decorative film 14 on their surface. A frame wood 15 with integrated silicone seal 16 forms the lateral end of the door leaf.
The three intermediate layers are connected to one another by point-by-point gluing with known urea or white glues, by staples or staplers. In this way better acoustic properties of the door leaf are realized. Sufficient shear stresses can be transmitted through the partial gluing, which inevitably occur when the door is moving and would lead to increased noise when the glue is applied over the entire surface. After the door leaf is prepared as a sandwich element, the final finish is done by laminating the surface with a 0.3 mm thick polypropylene decorative film. The PP film is applied to the glued surface of the mold decks on known membrane presses. The PP film covers the entire surface of the door leaf. The fold area is foiled on a separate press. Due to the closed film up to the fold area, moisture penetration is effectively prevented.

FIG. 6 also shows a side view of two symmetrically designed mold decks 1 which are arranged in mirror image to one another. The design possibilities that result from the high level of plasticity of the starting material and the manufacturing technology used become visible.

Figure 7 illustrates the advantageous storage of the thin-walled mold deck 1 in the package. The mold decks are designed in such a way that the full surface of the parts is guaranteed in the package and any warping during the cooling phase of the freshly pressed mold decks is reliably avoided. Storage in the package advantageously enables uniform conditioning of the mold decks. The water that has diffused into the near-surface areas of the deck while pressing through the cooling bath after pressing can evenly creep into the interior of the molding deck.
The geometrically thinner profile areas of the mold deck are given greater strength by realizing a higher degree of deformation during pressing. The increased mechanical strength of the unsupported, profiled areas of the mold deck also has a positive effect on the subsequent press coating.
This special geometric design of the molded decks eliminates the space-intensive intermediate storage in individual shelves or high racks. Due to the high flexural strength, the parcels can be transported using lifting devices without the need for specially designed traverses.

Figure 8 shows the felting and compression of the fibers in three phases:

Figure A shows the loosened fibers that are evenly sprayed with binder. The initially non-compressed fiber fleece has an average thickness of approximately 400 mm to 600 mm.

Figure B shows the fiber fleece after pre-compression in a press to an average fleece thickness of 40 mm to 60 mm.

Figure C shows a highly stylized representation of the preformed semi-finished or finished part with a constant wall thickness of 4.0 mm.

FIG. 9 shows an example of a technological flow plan for the production of form decks, starting with the loosening of the raw fiber materials supplied. After an intermediate storage of the fibrous materials, which only serves to compensate for disturbances in the raw material supply, impurities are removed.

The loosened and cleaned fibrous materials are wetted with the liquid binder in a mixing plant. In an intermediate bunker, which acts as a buffer and at the same time, if necessary, allows the liquid binder to act on the fiber material for a longer period of time, the wetted fibers are applied to a forming belt via a fiber spreading machine before the spreading material reaches the pre-compression press.
After pre-compaction, a trimming cut follows the technologically necessary nominal dimensions of the fleece. The pre-compressed, trimmed fleece is transported to an interim storage facility via a downstream conveyor belt.
Depending on the technology-related production sequence, the buffered nonwovens are formed into semi-finished or finished parts in a clocked press line. After opening the press dies, the molded parts are removed. Then the still hot master parts pass through a cooling section (water bath or spraying with water). The moistening of the mold decks also serves for conditioning. This gives the decks a leveling moisture, which has an advantageous effect on the subsequent processing of the parts. Finally, the finished mold decks are transported to an interim storage facility on a conveyor belt.

The new form decks allow a high variability of their use:
Due to the variations in the intermediate layers, the door thicknesses, the number and shape of the seals of the rebates as well as the fittings and locking mechanisms, not only room and apartment entrance doors, but also soundproofing, smoke protection, fire protection, security and radiation protection doors can be manufactured using the molded decks become.

A particular advantage is the possibility of using a modular principle to produce cost-effective system doors for objects that look the same Characterize molded decks with different usage properties. So z. B. at the Design of a doctor's office, the burglar-resistant entrance door, the door to the X-ray room, the soundproof door to the treatment and meeting room and the Fire door of the storage room have the same external design elements as that simple room doors from adjoining rooms.

In the manufacture of a fire-retardant door, for example, an approximately 2 mm thick steel sheet and a 20 mm to 40 mm thick plasterboard, e.g. B. FERMACELL, integrated in the sandwich composite of the door leaf. The mechanical connection of these panels with the adjoining intermediate layers made of chipboard is achieved by gluing the entire surface with a suitable adhesive.
When manufacturing radiation protection doors, a thin-walled, approximately 3 mm thick lead foil is embedded from the adjacent intermediate layers of chipboard.
In the manufacture of soundproof doors, 2 - 4 intermediate layers made of 16 mm thick chipboard are connected to one another by stapling or gluing.
In order to increase the variety of shapes in the manufacture of differently designed surfaces on doors, the press dies for the primary shaping of the mold decks are selected according to a modular principle. This enables a combination of different form elements while reducing the manufacturing costs for the die forms.

Due to the variable arrangement of the different die shapes on the press table, a variety of shapes can be made possible with a comparatively small number of basic shapes.
In addition to the solid particle boards already mentioned, paper honeycombs or tubular particle boards are used as intermediate layers in door production.
In a preferred embodiment, a chipboard panel with a horizontal arrangement of the tubes is used as an intermediate layer of a soundproofing door. The tubes are filled with fine-grained minerals, preferably with sand. This enables a high level of sound insulation. The customer also sees the larger mass of the door as an expression of the solidity and reliability of the door system.
The edge banding of the doors is preferably made of knotty and tension-free straight wood, MDF material, veneer plywood or other known materials, if necessary also in combination with each other.

With the same manufacturing technology, molded decks for furniture or Furnishings are made.

As an alternative to the surface lamination of the doors or furnishings with a Depending on the customer's requirements, plastic film can also be used in known dipping or coating systems Spraying methods are applied.

In addition to the excellent manufacturing technology and design options, the derive from the good flow properties of the wood particle-binder mixture used result, the doors and furnishings manufactured according to the invention have a high durability and full recyclability. Thus, after the normative service life a material-appropriate separation of the product components and their recycling possible without any problems.

Overview of reference symbols used

1

molded deck

2

edge

3

midsection

4

center position

5

chipboard

6

profiling area

7

MDF particle board

8th

lipping

9

polypropylene film

10

liner

11

chipboard

12

MDF particle board

13

Aluminum barrier film

14

decorative film

15

wood frame

16

silicone packing

Claims (34)

Thin-walled, three-dimensionally shaped semi-finished or finished part for use as a cover plate in furniture construction, in door manufacturing and in comparable areas, in particular for use as strongly profiled sheets of profile doors for interior or Outdoor, consisting of a mixture of wood and / or wood fiber material and / or vegetable fiber particles and a liquid, heat-reactive binder with a mass fraction of the mixture of 2% to 8%, the average length of the fibers being 1.5 mm to 20 mm and the average thickness is 0.05 mm to 1.0 mm, and the cohesion of the mixture is created by pre-compression and subsequent shaping with the application of pressure and heat, and that at least one top surface of the shaped semi-finished or finished part is coated with a thin-walled plastic film or a biodegradable paint system. Thin-walled, three-dimensionally shaped semi-finished or finished part for use as a cover plate in furniture construction, in door manufacturing and in comparable areas, in particular for use as strongly profiled sheets of profile doors for interior or Outdoor, consisting of a mixture of wood and / or wood fiber material and / or vegetable fiber particles with a proportion of 75 M% to 95 M% of slim fiber particles, based on the total mass of the particles, the average length of the fibers or fiber particles 1.5 mm to 20 mm and the average thickness 0.05 mm to 1.0 mm is, with a proportion of 5 M% to 25 M% of essentially cubic or approximately spherical wood, wood-based material or fiber particles with a fraction size between 0.005 mm and 1.0 mm, and a liquid, heat-reactive binder with a mass fraction of the mixture of 2% to 8%, the cohesion of the mixture being created by pre-compression and subsequent shaping with the application of pressure and heat,
and that at least one top surface of the shaped semi-finished or finished part is coated with a thin-walled plastic film or a biodegradable paint system. Semi-finished or finished part according to claim 1 or 2,
characterized in that the slender fiber particles are randomly matted together. Semi-finished or finished part according to one of claims 1 to 3,
characterized in that the fiber particles consist of digested wood chips or wood chips or plants or a mixture thereof. Semi-finished or finished part according to claim 1 or 2,
characterized in that the proportion of the binder in the mixture is preferably 4.0 M% to 5.0 M%. Semi-finished or finished part according to claim 1 or 2,
characterized in that the primary and reshaping of the fiber-binder mixture into a molded part takes place in a one-part or multi-part die at a pressing pressure of 20 bar to 45 bar and a hardening temperature in the die of 140 ° C. to 180 ° C. Semi-finished or finished part according to claim 6,
characterized in that the primary and reshaping of the mixture takes place in a one- or multi-part die on a single press or a multi-day press. Semi-finished or finished part according to claim 6,
characterized in that the primary and reshaping of the mixture takes place in a one-part or multi-part die on a single press with several rotating, heatable die forms. Semi-finished or finished part according to claim 1 or 2,
characterized in that the top surface of the shaped semi-finished or finished part is coated with a 0.1 mm to 0.5 mm thick plastic film. Semi-finished or finished part according to claim 1, 2 or 9,
characterized in that the plastic film is made of polypropylene. Semi-finished or finished part according to claim 1, 2 or 9,
characterized in that the plastic film consists of a polyolefin. Semi-finished or finished part according to claim 1, 2 or 9,
characterized in that the plastic film consists of polyvinyl chloride. Semi-finished or finished part according to one of claims 1, 2 or 9 to 12,
characterized in that the plastic film is colored and / or embossed and / or has a real wood grain. Semi-finished or finished part according to claim 1 or 2,
characterized in that the top surface of the preformed semi-finished or finished part is coated with an environmentally degradable paint system. Semi-finished or finished part according to claim 1 or 2,
characterized in that the semi-finished or finished part is used as a molded deck of a door leaf. Semi-finished or finished part according to claim 1 or 2,
characterized in that the semi-finished or finished part is used as a molded deck of furniture or an interior. Semi-finished or finished part according to claim 1 or 2,
characterized in that isocyanates or polyurethanes are used as binders. Semi-finished or finished part according to one of claims 1, 2 or 9 to 13,
characterized in that the plastic film is applied to the surface of the semi-finished product by means of a vacuum press. Semi-finished or finished part according to claim 1, 2 or 15,
characterized in that the semi-finished or finished part is used as a molded deck of a system door which can be used as an outer or inner door, room and entrance door, soundproof door, smoke protection door, fire protection door, safety door and / or radiation protection door. Semi-finished or finished part according to claim 1 or 15,
characterized in that air channels are arranged between the mold deck and the intermediate layer underneath and / or between adjacent intermediate layers. Semi-finished or finished part according to one of claims 1, 15, 16 or 20,
characterized in that two mold decks are connected with polyurethane foam, the adhesive bond between the mold deck and polyurethane foam being limited to the area portions of this perforation by two perforated paper webs inserted and tacked to the mold decks. Semi-finished or finished part according to claim 1 or 2,
characterized in that the average wall thickness of the semi-finished or finished part is 3 mm to 6 mm. Semi-finished or finished part according to claim 1 or 2,
characterized in that the semi-finished or finished part has a constant wall thickness. Semi-finished or finished part according to claim 1 or 2,
characterized in that the surface contour of the base and top surface is ideal and enables a direct stacking of superimposed semi-finished products or molded parts. A method for producing a thin-walled, three-dimensionally shaped semi-finished or finished part according to claim 1,
characterized in that the semi-finished or finished part made of a mixture of wood fiber particles with an average length of the wood fibers of 1.5 mm to 20 mm and an average thickness of 0.05 mm to 1.0 mm and a liquid, heat-reactive binder with a mass fraction is formed on the mixture from 2% to 8% in a heatable permanent mold under a pressure of 20 bar to 45 bar depending on the product and at a reaction temperature of 140 ° C to 180 ° C. A method for producing a thin-walled, three-dimensionally shaped semi-finished or finished part according to claim 2,
characterized in that the semi-finished or finished part from a mixture from slender wood fiber particles with an average length of the wood fibers of 1.5 mm to 20 mm and an average thickness of 0.05 mm to 1.0 mm, whose share in the total mass of the particles is 75 M% to 95 M%, and from essentially cubic and / or approximately spherical wood fiber particles with a fraction size between 0.005 mm and 1.0 mm, their share in the total mass of the particles 5 M%. is up to 25 M%, and a liquid, heat-reactive binder with a mass fraction of the mixture of 2% to 8% in a heatable permanent mold under a pressure of 20 bar to 45 bar depending on the product and at a reaction temperature of 140 ° C to 180 ° C. The method of claim 1 or 2,
characterized in that the wood and / or wood fiber material and / or vegetable fiber particles are defibrated in a defibrator after prior plasticization and dried in a further step. The method of claim 27
characterized in that the moisture content of the fiber particles is adjusted to 6% to 10%. The method of claim 27
characterized in that the average size of the fiber particles is adjusted by changing the width of the grinding gap and / or the length of time in the defibrator. Method according to one of claims 1, 2, 27 or 28,
characterized in that the dried, loosened and adjusted to a predetermined residual moisture content of the fiber particles are wetted with the liquid binder, formed into a nonwoven fabric and pre-compressed. A method according to claim 30,
characterized in that the pre-compressed fleece is trimmed in length and width and subsequently formed into a semi-finished or finished part in a preheated die. A method for producing a thin-walled, three-dimensionally shaped semi-finished or finished part according to claim 1,
characterized in that the semi-finished or finished part from a mixture of different lignocellulosic fibers with an average length of the fibers of 1.5 mm to 20 mm and an average thickness of 0.05 mm to 1.0 mm and a liquid, heat-reactive binder with a mass fraction of the mixture of 2% to 6% in a heatable permanent mold under a pressure of 20 bar to 45 bar depending on the product and at a reaction temperature of 140 ° C to 180 ° C. A method for producing a thin-walled, three-dimensionally shaped semi-finished or finished part according to claim 2,
characterized in that the semi-finished or finished part from a mixture made of various slim lignocellulosic fibers with an average length of the fibers of 1.5 mm to 20 mm and an average thickness of 0.05 mm to 1.0 mm with a share in the total mass of the particles of 75 M% to 95 M% and from various, essentially cubic or approximately spherical lignocellulosic fibers with a fraction size between 0.005 mm and 1.0 mm with a proportion of the total mass of the particles of 5 M% to 25 M%, and a liquid, heat-reactive binder with a mass fraction of the mixture of 2% to 8% in a heatable permanent mold under a pressure of 20 bar to 45 bar depending on the product and at a reaction temperature of 140 ° C to 180 ° C. Method for producing a thin-walled, three-dimensionally shaped semi-finished or finished part according to one of claims 1, 2, 25, 26 or 33,
characterized, that the mold decks are pressed together with the intermediate layer, in particular in the area of the edge band of a heated press, and that at least one bore arranged in the edge band creates a negative pressure between the mold deck, edge band and intermediate layer.

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