DE102009034706A1 - Coated and reinforced wood and plastic sheets and methods of making such wood and plastic sheets - Google Patents

Abstract

The present invention is a process for coating and reinforcing wood and plastic plates, as they are used as underlays in the concrete block industry, and wood and plastic sheets provided with such a surface coating and reinforcement, especially used backing plates that require a work-up.

Description

The The present invention relates to a method of coating and Reinforcement of wood and plastic panels, as they are called Base plates are used in the concrete block industry, and Wood and plastic panels provided with such a surface coating and reinforcement, in particular used underlay panels, which require a work-up.

sole plates serve in the production of concrete products, such as composite bricks, Plates, blocks, curbs and the like, as a support during the manufacturing process of concrete moldings. The underlay plates are taken for this purpose from shelf storage and in a molding machine introduced, which a raised and lowered form and a Compression stamp with stamp plate has. The base plate is pushed below the mold on a vibrating table, which can be vibrated by an eccentric or the like. After inserting the base plate, the mold is on the board lowered and topped with a mixture of concrete or other hardening materials filled. The filled Mixture is made by the pressure of the above-lowered press ram and compresses the vibrations of the vibrating table. Subsequently Press ram and mold are pulled up and the base plate with the concrete molding thereon from the molding machine out on transport rails by means of a latch band or similar Transport facilities moved to spent in a drying room to become where the concrete molding hardens. In a removal station is the cured concrete moldings as finished concrete product removed from the base plate and in a warehouse for final curing and drying out fed.

There the loaded base plates often only on two edge areas on the rails of the stacking cart, the shelf rails of the drying room or on stack feet must rest to the flexural rigidity of the base plate even with longer Storage and possibly supplied heat of drying high demands are made.

If the base plate is not sufficiently flat, arise in the Curing the solidified concrete mixture crazing, which affect the quality of the concrete product. For a high quality smooth surface of concrete blocks It is also important that the base plate seamless and without cracks.

sole plates are largely made of wood, with different ones Wood species such as fir, spruce or pine, as well as various tropical woods be used. These boards are available in many different ways Dimensions. Their construction can be layered with glue, with or without tongue and groove, with reinforcements (eg iron bars) and be formed. Base plates made of softer European Main wood species are subject to greater wear, on the other hand but is the use of woods from the tropical rainforests to avoid from an ecological point of view.

It are still known backing plates, which are recycled from thermoplastic materials are produced. To increase the bending stiffness in the longitudinal direction of the base plate either reinforcing tubes in the plate body be cast in the longitudinal or transverse direction or it will be U- or C-shaped metal reinforcement rails attached to the longitudinal edges of the plate body. The disadvantage is the weight of such a board made of plastic to call with metal reinforcements. Besides that, too proved to be disadvantageous that a lack of connection to the metal reinforcements and low impact toughness of the thermoplastic of the board can lead. From a too low bending stiffness is the outer shape of a concrete part produced thereon impaired, since the base plate is part of the manufacturing form of the concrete part forms.

Adjacent is a base plate made of a wood material as the core section ( DE 102005058983 B4 ) provided on all sides with a protective layer of a plastic. For this purpose, pourable PU plastic has been proposed. The wood material usually has a much higher flexural rigidity than the plastic.

The in the concrete industry used underlay plates, in particular if they are made of wood, are subject to the first day of production at a wear of the surface, as well as a structural weakening and usually need replaced at regular intervals become. This means a huge resource consumption and corresponding Costs.

The Object of the present invention is therefore to provide a base plate to provide which avoids the above disadvantages as much as possible and improved resistance to deflections, a smooth and highly resistant surface finish and has a high dimensional accuracy. About that In addition, the inventive measures even when using softwoods such as pine, fir or Spruce have a high strength, also in terms of abrasion, possess and softwood panels lent properties like hardwood boards otherwise exhibit.

The object is achieved by the subject matter of the independent claims. Preferred embodiments of the invention are specified in the subordinate claims or described below.

The Coating is by means of a hardening plastic produced. This forms, when solidified, hard and simultaneously high impact and weather resistant surfaces, which gives the plates effective wear protection. At the same time the plastic ensures a better Separation to the concrete material and helps the consumption of release agents minimize during concrete production. The surface can usually be done by brushing free the adhering concrete residues.

The used underlay plates (plate material) are made of wood, including Wood-based materials, such as ORF layered, barrier, chipboard or plywood boards, and / or plastic. The plastic material is common a recylate. Particularly advantageous is the base plate in Core of wood. This core section of wood is covered with a plastic layer the top and bottom coated, whereby the wood also prevails penetrating moisture and wood pests protected becomes.

The End faces and / or the longitudinal edges are according to a preferred Embodiment, however, cut from the coating, to ensure that this moisture diffusion. An advantage of wooden panels over pure plastic panels is that they have a reduced weight, what in handling, storage and transport is advantageous.

The Plastic plates consist in particular of a recylate. This can high proportions (eg greater than 30 wt .-% or in particular greater than 50% by weight) of polyvinyl chloride (PVC) included.

When Another example may be called plastic waste, the essentially have the following composition: 70-90% by weight Polyolefins, 0-15% by weight Polystyrene 0-10% by weight PVC, possibly residual components of other plastics and / or dirt.

The Plastic cover layer on the top and bottom of the base plate preferably has an average thickness of 1 to 5 mm, in particular 1 to 2.5 mm.

As the coating material for producing the plastic top layer, epoxy resins, polyester resins and polyurethane resins (including polyurea resins) are particularly suitable. The coating material can be applied in quantities of 1.5 to 3.5 kg per m ^{2 of} plate surface.

When PU plastics can be used those which mixtures from 30 to 50 parts by weight of hard and 80 to 120 parts by weight Have polyol.

in the Cases of using PU one-component systems are particularly suitable according to the invention Reaction products of any organic polyisocyanates with Substandard amounts of compounds with against Isocyanate groups reactive hydrogen atoms in an equivalent ratio of isocyanate groups towards isocyanate-reactive groups of 1.5: 1 to 15: 1 (NCO prepolymers). In case of using the NCO prepolymers are preferably cured by reaction with water. The water can be contained in the substrate or added to the substrate.

at the use of two-component systems are organic polyisocyanates with compounds having isocyanate-reactive Groups in an equivalent ratio of approx. 0.8: 1 to 1.2: 1 used. Here, the mixing of the Reaction components just before use. The curing is then carried out by the between the isocyanate groups and the opposite Isocyanate-reactive groups spontaneously expiring Isocyanate addition reaction.

Either for the preparation of NCO prepolymers and as a reaction component Polyisocyanates can be used in the two-component systems be such. Hexamethylene diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyantomethylcyclohexane, 2,4- and 2,6-toluene diisocyanate and any mixtures of these Isomers, 4,4'-diphenylmethane diisocyanate and 4,4'-dicyclohexylmethane diisocyanate.

usable are also NCO-containing biurets, uretdiones, trimers and other reaction products of said monomeric polyisocyanates.

Both for the preparation of the NCO prepolymers and as a reaction component in the two-component systems, any, in the sense of the isocyanate addition reaction at least difunctional compounds with isocyanate-reactive hydrogen atoms can be used. Preferably, the corresponding hydroxyl, amine and / or sulfhydryl-containing polymerization or polycondensation products having a molecular weight of 150 to 10,000, preferably 1000 to 5000, are used. Examples of these are the polyether polyols known in polyurethane chemistry, such as those produced by polymerization, copolymerization or block copoly merization of alkylene oxides, such as ethylene oxide, and / or propylene oxide using di- or polyfunctional active hydrogen atoms starter molecules, such as. For example, water, ammonia, ethylenediamine, ethylene glycol, trimethylolpropane, glycerol, pentaerythritol, sorbitol, phosphorous acid and phosphonic acids can be obtained. Also suitable are polyacetals, such as. As the polycondensation products of formaldehyde and diols or polyols of the aforementioned type, as they can be obtained using acidic catalysts.

preferred Polyisocyanates for preparing the prepolymers are 4,4'-diphenylmethane diisocyanate or isomer mixtures of 4,4'- and 2,4'-diphenylmethane diisocyanate. Particularly suitable polyisocyanate mixtures consist of a) 0-5% 2,2'-diisocyanatodiphenylmethane, b) 20-80, preferably 30-70% 2,4'-diisocyanatodiphenylmethane and c) 80-20, preferably 70-30% 4,4'-diisocyanatodiphenylmethane and / or higher as difunctional polyisocyanates of the diphenylmethane series.

Besides The PU masses may contain auxiliaries and additives. This is, for example, in polyurethane chemistry common catalysts such. B. tertiary Amines or organic metal compounds, plasticizers, in particular those are characterized by resistance to distinguish the alkaline components of the structures, such. B. Phosphoric acid esters, as well as reaction products of chlorosulfonated Paraffins with phenol and phenol derivatives, pigments in powder form or as pastes, inorganic fillers, such as. Sand, Kaolin, chalk, barium sulfate, silicon dioxide, emulsifiers, flame retardants, Anti-aging agents or adhesion promoters. To stabilize the through Carbon dioxide formation resulting foam structures can also known from polyurethane chemistry Polyetherpolysiloxane to be used with. Although it is in the inventive Method to be used PU compositions preferably solvent-free Systems is the co-use of solvents such as As ethyl acetate, butyl acetate or xylene is not in principle excluded.

To an embodiment of the present invention is particularly advantageous when the curing plastic together with a natural fiber mat, z. Hemp, jute, coconut, Sisal, flax, wood fibers, textile fibers or mixtures thereof, applied becomes. The mats are cut to size Plate top and bottom placed. Overhanging areas can after curing by edge or corner milling be separated. The mats are compressible and the plastic penetrates these, unloaded, these preferably have strengths from 6 to 8 mm and after compaction from 1.5 to 2.5 mm.

Instead of or in addition to using a natural fiber mat also grinding or sawdust of wood or plastic materials be incorporated, in particular, that of grinding operations the underlays comes. Such materials can be incorporated in one of the binder components, for. In the polyol component when using a PU plastic.

For pressing the coating, pressures of in particular 0.5 to 4 kg / cm ² can be used. In the case of temperature-curing PU plastics in this case temperatures of 50 to 80 ° C are applied. The thermosetting plastics can be applied by casting or spraying. The reaction time in the press can be 4 to 6 minutes. The coating can be fully loaded after approx. 72 hours. In particular, when coating new, ie unused wood or plastic plates can also be dispensed with the use of mats and pressing.

The Base plates have recesses. The plastic to the Filling the recesses is preferably the same as for coating, watering and / or pressing, if necessary under the action of heat.

The in the plate surfaces on both sides or unilaterally introduced Line-shaped recesses preferably have widths from 5 to 30 mm and depths from 2 to 15 mm, especially 5 to 10 mm up. Preferably, recesses are at an angle of 20 up to 60 °, in particular 40 to 50 °, relative to Surface normal milled out to undercuts train. Preferably, the recesses therefore at least an undercut and are z. In the form of a dovetail groove or an incision angled to the surface executed.

The Recesses can be spaced 5 to 8 cm apart be executed and are particularly preferably close to the Edges as edge protection over the entire length or width of the plate. At the same time the edges after curing of the coating and in particular the filled recesses, according to one embodiment the edges form chamfered or broken executed as another edge protection.

One Milling is always possible without any problems if C-rails and screw-in bars do not reach the plate edges pass. Therefore, an optional metal rail advantageously arranged in particular about 2 mm below the plate surface.

To an embodiment of the invention are the end faces, especially where there takers for the longitudinal transport attack the pads, such. B. pawls at a pawl feed, provided with hardwood or plastic plugs. these can preferably 0.1 to 2 mm, in particular 0.5 to 2 mm from the end faces stand out. The slots for picking up the hardwood or plastic plugs preferably have a depth of 2 to 10 cm, preferably 4 to 6 cm, and a width (optionally as a diameter) of 20 to 30 mm and are especially round. Per driver are preferably 1 to 3 hardwood or plastic plugs provided, d. H. per face 2 to 6. In case of use Plastic plugs are preferably made of the same material how the surface coating is made.

Especially when using softwood panels reinforce with plastic filled openings advantageous the material of Shim. The openings point in one plane of the surface advantageously diameter of 1 to 8 cm, in particular from 2 to 6 cm, up. The openings are arranged in particular there where the concrete forms are laid The openings are as running through holes. The through holes have in particular double wedge shape, d. H. they dilute towards the center and have a wider extension on both sides in the edge area or the other way around. Transfer the holes filled with plastic the vibration of the vibrating table particularly effective the shape and avoid overstressing the base plate especially if it is made of softwood.

• (a) Bereitstellen einer Unterlagsplatte aus Holz und/oder Kunststoff;
• (b) ggf. Abschleifen der Oberfläche, z. B. um im Mittel 1 bis 3 mm, z. B. bei gebrauchten Unterlagsplatten,
• (c) Einfräsen oder Sägen von Ausnehmungen, vorzugsweise streifenförmigen Ausnehmungen, insbesondere im Kantenbereich und/oder Einbringen von Durchbrechungen,
• (d) Auffüllen der Ausnehmungen und Durchbrechungen mit einem aushärtendem Kunststoff,
• (e) Versehen der Ober- und Unterseite der Platte mit einer Kunststoffbeschichtung. Die Beschichtung kann entweder nur als flüssiger Kunststoff (mit oder ohne Füllstoffe und andere Additive) oder in Verbindung mit einer – idealerweise PU-getränkten – Fasermatte aufgebracht werden. Die benetzte Matte wird hierzu aufgelegt, ggf. auch als teil- oder ganz ausgehärtete dünne Platten umfassend die Matte,
• (f) Aushärten der Kunststoffbeschichtung, bei Einsatz einer Fasermatte insbesondere unter Verpressen der getränkten Fasermatte unter Anwendung von Wärme zum Aushärten des PU-Kunststoffes.

The method according to the invention for producing the base plates has the following method steps:

• (A) providing a base plate made of wood and / or plastic;
• (b) if necessary abrading the surface, z. B. to an average of 1 to 3 mm, z. B. in used boards,
• (c) milling or sawing recesses, preferably strip-shaped recesses, in particular in the edge region and / or introducing apertures,
• (d) filling the recesses and openings with a hardening plastic,
• (e) Cover the top and bottom of the plate with a plastic coating. The coating can be applied either only as a liquid plastic (with or without fillers and other additives) or in combination with a - ideally PU-impregnated - fiber mat. The wetted mat is placed for this purpose, possibly also as partially or fully cured thin plates comprising the mat,
• (F) curing the plastic coating, when using a fiber mat in particular under compression of the impregnated fiber mat using heat to cure the PU plastic.

To the method of the invention can refurbished new pads and worked up worn pads become. The base plates are according to the invention Process coated with a highly abrasion-resistant material.

usable are usual bases made of softwood or hardwood as well as plastic or multilayer plates. critical is that here also a structural strengthening of the Wood panel is made, as the plastic in all milled penetrates the plate and makes a firm connection with the wood. The optional pressing leads to underlay plates Softwood in addition to significantly compacting the boards, whereby the bulk density and strength are increased.

So far It was common to use used underlays due to excessive wear and structural damage after a few years to exchange for new plates, which regularly associated with high investment.

• • eine zusätzliche Behandlung mit Wasser oder Öl ist nicht mehr erforderlich,
• • ein Austrocknen von Platten, die aus dem Kreislauf genommen wurden, wird verhindert,
• • die Oberfläche ist fugenlos, planeben und hochabriebfest,
• • beschichte Platten bieten hervorragende Verdichtungseigenschaften,
• • die Tragfähigkeit der Platten wird erhöht, womit auch Produkte mit hohem Gewicht rissfrei gefertigt werden können,
• • die Maßhaltigkeit der Produkte wird deutlich verbessert
• • die Beschädigungen an den Ecken oder Kanten werden deutlich reduziert und
• • auch nach Jahren der Nutzung kann eine erneute Neubeschichtung problemlos erfolgen.

The repair and coating process according to the invention renovated old, worn plates again and thus offers significant cost savings potential. New underlay boards, in particular made of softwood, obtained by the coating according to the inventive properties which ensures quality improvement and cost savings in the production of concrete products. After coating, the following aspects can be observed:

• • additional treatment with water or oil is no longer necessary
• • Dehydration of plates that have been removed from the circulation is prevented
• • the surface is seamless, level and highly abrasion resistant,
• • coated panels offer excellent compaction properties
• • the load-bearing capacity of the panels is increased, which means that even products with high weight can be manufactured without cracking,
• • The dimensional stability of the products is significantly improved
• • the damage to the corners or edges are significantly reduced and
• • Even after years of use, re-coating can be carried out without difficulty.

The abrasion test was based on the DIN EN ISO 5470-1 (09/1999) . ISO 7784-2 (02/1997) and ASTM D 4060-01 , carried out according to the method CS10 / 1000/1000 for a PU coating. It is a commonly used method to test heavy-duty industrial floor coatings. According to this method, the pads have an average abrasion of 62.5 mg.

at the highly abrasion resistant floor coatings is the Attrition by this method between 50 mg and 70 mg. In a comparison test was found that the abrasion value of uncoated larch plates around 120 mg.

Uncoated Underlays show after many years of use in many cases not only a badly worn surface on, but are often also damaged at the edges, caused by mechanical effects during horizontal transport and during stacking / unstacking the plates.

The Invention is based on embodiments in the Drawings explained in more detail, without being limited thereto to be. Show it

1 : a base plate in longitudinal section and

2 : the top view of a base plate.

In 1 is a base plate 1 shown in longitudinal section. The upper 2 and subpages 3 of the core 10 made of wood or plastic are next to the coating 4 at the top and bottom filled with PU plastic recesses 5 Mistake. The recesses 5 as shown different shapes (oblique incisions 5 ' and 5 '' or triangular shape 5 '' ) to have. Particularly preferred are dovetailed recesses ( 5 '' ).

Likewise are filled with plastic openings 11 shown. The openings are arranged in the plate surface substantially perpendicular to the conveying direction, especially where the concrete forms are placed. Breakthroughs can be used as holes ( 11 ' ) in the plate surface or as through holes ( 11 '' ), z. B. in wedge or trapezoidal shape.

On two of the long sides ( 6 ) of the base plate 1 are reinforcing rails ( 7 ) molded with C-shaped profile. On the front side ( 8th ) engage the longitudinal conveyor (indicated by arrows). The front side ( 8th ) is with inserts ( 9 ), which are firmly inserted in slots. The front pages ( 8th ) are not covered with plastic.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 102005058983 B4 [0007]

Cited non-patent literature

• - DIN EN ISO 5470-1 (09/1999) [0040]
• - ISO 7784-2 (02/1997) [0040]
• ASTM D 4060-01 [0040]

Claims (13)

Base plate ( 1 ) provided with a coating ( 5 ) of a hardening plastic on the upper ( 2 ) and underside ( 3 ) a wooden or plastic plate ( 10 ), characterized in that the coating ( 5 ) on the upper ( 2 ) and underside ( 3 ) of the wood or plastic plate ( 10 ) have a mean thickness of 1 to 5 mm and are further provided: a) recesses in the wood or plastic plate with a width of 5 to 30 mm and a depth of 2 to 30 mm and the recesses ( 5 ) are also filled with a hardening plastic, so that the filling of the recesses ( 5 ) and the coating ( 4 ) form a firmly connected unit and / or b) several openings ( 11 ), whereby the openings ( 11 ) the upper ( 2 ) and underside ( 3 ) and are filled with a hardening plastic as a filling, wherein the filling of the openings ( 11 ) and the coating ( 4 ) form a firmly connected unit and / or c) on at least one end face of the base plate several hardwood or plastic plugs ( 9 ) in oblong holes of a depth of 2 to 10 cm and a width of 20 to 30 mm. Base plate according to claim 1, characterized in that the curing plastic a polyepoxide, a polyester and / or a polyurethane, in particular a thermosetting polyurethane. Base plate according to claim 1 or 2, characterized in that coating and filling of the recesses ( 5 ) consist of the same plastic. Base plate according to at least one of the preceding claims, characterized in that the coating is applied in quantities of 1.5 to 3.5 kg per m ² plate surface. Underlay plate according to at least one of the preceding claims, characterized that in the coating a natural fiber mat and / or fillers, such as sawdust, natural fibers and / or inorganic particles, are incorporated. Base plate according to at least one of the preceding claims, characterized in that the recesses ( 5 ) Have undercuts. Base plate according to at least one of the preceding claims, characterized in that the recesses ( 5 ) are linear and the lines preferably extend substantially over the entire plate. Base plate according to at least one of the preceding claims, characterized in that the recesses ( 5 ) are arranged at least close to the edges as edge protection and are independently of this preferably carried out with 5 to 8 cm apart from each other. Backing plate according to at least one of the preceding claims, characterized in that the hardwood or plastic plugs ( 9 ) from the front side ( 8th ), preferably by 0.1 to 2 mm. Underlay plate according to at least one of the preceding claims, characterized that the hardwood or plastic plugs in the area of the driver a conveyor transport device are arranged. Method for producing the underlay plates according to at least one of the preceding claims, comprising the following method steps: (a) providing a base plate ( 1 ) made of wood and / or plastic; (b) if necessary abrading the surface ( 2 . 3 ) to an average of 1 to 3 mm, (c) milling and / or sawing strip-shaped recesses ( 5 ), in particular in the edge region and / or introduction of openings ( 11 ), (d) filling in the recesses ( 5 ) and / or perforations ( 11 ) with a hardening plastic, (e) providing the upper ( 2 ) and underside ( 3 ) of the plate ( 10 ) with a plastic coating of thermosetting plastic, and (f) curing the plastic coating, in particular under compression and / or with the application of heat, and the filled-in recesses ( 5 ) and / or the filled openings ( 11 ). Process according to claim 11, characterized characterized in that step (e) is the introduction of a fiber mat or fillers, such as sawdust, natural fibers and / or inorganic particles, in particular a natural fiber mat, in the plastic coating. Use of the base plate ( 1 ) according to at least one of claims 1 to 10 in the concrete industry as a substrate for concrete products during the molding process.

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