MX2008009120A - Method for producing a cladding element - Google Patents

Abstract

The invention relates to a method for producing a cladding element (10) comprising a base panel (12), one surface (12a, 12b) of which is provided with a resin-impregnated paper layer (14, 18). According to the invention, in a first step (BID, BIR), the resin is applied to the surface (12a, 12b) of the base panel (12), in a second step (DS, RS), the paper layer (14, 18) is applied to the surface (12a, 12b) of the base panel (12) and in a third step (HP), the base panel (12), whose surface (12a, 12b) has been provided with resin, and the paper layer (14, 18) are laminated.

Description

METHOD FOR THE PRODUCTION OF A COATING ELEMENT DESCRIPTION OF THE INVENTION The invention relates to a method for the production of a coating element, for example, a floor panel, a wall covering element, an element visible front of a piece of furniture, or the like, the covering element comprising a substrate sheet which is provided on a surface, namely on its visible side or on the supporting surface, opposite the visible side, with a layer of paper soaked with resin. Methods of this type according to the state of the art are public knowledge. Such a method is described below with reference to Fig. 2. But already at this time it is anticipated that the method of the state of the art, described below, does not differ in terms of the materials used in the inventive method. All the indications that are made in relation to the known method, as well as the indications in relation to other parameters such as layer thicknesses, grams and the like, apply, therefore, also in the same way for the inventive method. Both the known method, whose method steps are shown schematically in FIG. 2, and also the inventive method discussed below, have as their objective the production of a coating element 10, as shown in FIG. 3: The coating element 10 comprises a substrate plate 12 which is preferably formed of a wood material, for example a chipboard or a fiber board, for example an MDF plate (medium density fiberboard, by its acronym in English) or an HDF plate (high density fiber board, for its acronym in English). In case the coating element finds application as a floor panel, then it preferably has a thickness of about 5mm to about 15mm. On its visible side 12a the substrate plate 12 is provided with a layer 14 of decorative paper comprising at least one sheet 16 of decorative paper. On its visible side 14a the layer 14 of decorative paper, respectively, the sheet 16 of decorative top paper, is printed with a desirable decoration, for example, a decoration that imitates wood, stone, tiles or materials, respectively, similar products. The paper used for the decorative paper layer 14 usually has a total gram index of about 45 g / m2 to about 160 g / m2. Decorative papers of this type are impregnated, respectively, soaked with an impregnating resin in special impregnation machines, which is indicated in FIG. 3 with a dotted line. The amount of impregnation resin applied, referred to the weight of the raw paper of the decorative paper layer 14, amounts to approximately 100% to approximately 140%. In order to prevent a deformation of the covering element 10 due to the stresses coming from the decorative paper layer 14, for example a bending, which destroys the completely flat and extended configuration desirable, it is possible that it is optionally arranged on the face 12b posterior, disposed on the side opposite the visible face 12a of the substrate plate 12, a layer 18 of opposite pull paper. The layer 18 of the counter-tensioned paper is also impregnated with impregnation resin, as insinuated by the dotted line in FIG. 3. With respect to the weight of the raw paper, ie the gram number of the waste paper, and the amount of the impregnation resin applied, the opposite pull paper 18 corresponds essentially to the decorative paper layer 14, to ensure that both paper layers 14 and 18 exert tension actions on the substrate plate 12 which essentially they cancel each other. In order to protect the decorative paper layer 14 against erosion, which is important not only in the use of the covering element 10 as a floor panel, but also in its use as a wall covering element or as a visible front furniture element, a layer 20 of coating paper (designated in the technical terminology can also be applied optionally on the visible side 14a of the decorative paper layer 14). paper layer "Overlay"). The usual coating papers, respectively, Overlay papers preferably have a weight of rough paper of about 10 g / m2 to about 80 g / m2, and are transparent, in particular when soaked with impregnation resin, so as not to obstruct the view to the decoration of decorative paper layer 14. In relation to the weight of the raw paper, the amount of impregnating resin amounts to between approximately 100% and approximately 300%. To increase the erosion resistance, a suitable additive, for example corundum, can be mixed with the impregnating resin for the coating paper layer 20, preferably in an amount of about 5 g / m2 to about 50 g / m2. As the impregnation resins, aminoplast resins are preferably used, for example, urea resins or melamine resins, or mixtures of urea and melamine resins, the use of melamine resin being preferred to impregnate the coating paper layer 20 . The known method for the production of such a coating element 10, whose method steps are shown schematically in FIG. 2, is oriented in the production cycle of the substrate plate 12. It is therefore necessary to store all the papers used in the sheet metal structure of the covering element 10 in reserve tanks in order to avoid delays in the advance of the substrate sheets 12. In step D, as an example, a printed decorative paper 14 is prepared with a desirable decoration. This is impregnated in a DI stage with the impregnation resin in a special impregnation machine. The impregnation resin can be applied, in this, in one or several steps in the decorative paper 14, penetrate it and finally dry. The decorative paper 14, thus impregnated, is subsequently formatted in an additional DF stage, that is, cut to a size adjusted to the size of the fed substrate plates 12. The decorative paper 14 is now ready for further processing, in particular, the hot pressing for joining it to the substrate plate 12, and is fed in a stage DL to an intermediate container 22, where it remains until further processing.

Analogously, the counter-tensioned paper 18 and the coating paper 20 are fed in stages R and O, analogous to stage D, such as raw paper, and are impregnated in stage Rl or 01, analogous to stage DI, with impregnation resin, is cut to format in the RF and OF stage, analogous to the DF stage, and is fed in the stages RL and OL, analogous to the DL stage, to intermediate tanks 24 and 26, analogous to the intermediate tank 22 . If a substrate plate 12 is now fed in stage B, then in each case DS, RS and OS in each case a decorative paper 14, counter-tensioned paper 18 and coating paper 20, impregnated and cut to size, are removed, of the associated intermediate deposits 22, 24 and 26, and stacked in the sequence described above with reference to Fig. 3. This pile is then fed in an HP step to a hot stamping press 28 in which the layers are bonded. 14, 18 and 20 of paper with the substrate plate 12 to form the desirable finished product, namely the coating element 10, using an increased pressure and an increased temperature. However, the hot stamping press 28 is very schematically insinuated in the form of two press plates, that is, in the form of a press that operates stationary, it is understood that presses working with the same type can also be used. continuous or virtually continuous, for example, step presses. The known method has the disadvantage that the papers, impregnated with the impregnation resin, have only a storage stability limited in time. Namely, the impregnation resin must not be completely dry before the hot pressing, but must only be dried on contact with the individual layers of paper in the intermediate tanks, as an example, the intermediate deposit 22 for the decorative paper 14 , do not stick together. However, the papers continue to dry in the intermediate tank, in particular the impregnation resin with which they are soaked, so that they reach a degree of drying, in the case of an excessive storage period, which no longer allows a pressing in. hot tidy Paper impregnated with an excessive storage duration, therefore, must be separated and eliminated, which is a disadvantage not least because of the high material costs for the aminoplast resins, usually used for impregnation. Against this, it is the object of the present invention to indicate a method of the type mentioned initially that allows to reduce the wasted quantities, if not to avoid them altogether. This objective is achieved inventively by a method of the type mentioned initially in what is applied in a first stage the resin to the surface of the substrate plate and in what, in a second stage that follows in time to the first stage, is placed the layer of paper on the surface of the substrate plate and in which, in a third stage that follows in time to the second stage, the substrate plate, provided with resin on the surface, and the paper layer are joined by pressing. That is, the paper layer with resin is not impregnated before the intermediate storage, but it is put in contact with the resin, applied in the substrate plate, only during the pressing connection of the paper layer and the substrate plate and soak in this with the resin. That is to say, the impregnation itself is carried out only in the union by pressing. The raw paper, therefore, can be deposited in an intermediate way so that it is no longer subject to a temporary restriction as to the duration of the intermediate storage. It is understood in this sense by raw paper, in the case of the decorative paper layer, also paper already printed with the decoration. Because the resin is applied inventively in the substrate plate, it is furthermore guaranteed that the resin is always consumed only when there are indeed substrate plates for processing. The resin can be applied on the visible surface or / and the support surface, by way of example, with a weight per area of between approximately 50 g / m2 and approximately 200 g / m2. The application can be carried out, by way of example, by means of a cylinder application mechanism that is, in itself, known. In a further development of the invention, a hardener, necessary to harden the resin, preferably as a mixture of resin and hardener, can be applied to the surface of the substrate board in the first stage together with the resin. As an alternative it is also possible, and even advantageous, if the hardener and the resin are applied to the surface of the substrate plate in two separate stages from each other. And to wit, the hardener is preferably applied in a fourth stage that precedes the first stage, separated from the resin, on the surface of the substrate plate. By this variant of the method, mentioned last, the problem can be avoided that the resin, once mixed with the hardener, must be processed within a predetermined processing period, also called pot time. This has as a consequence a further reduction in the risk of waste of material and therefore contributes to a reduction in the production costs of the coating elements. As the hardener, there can be used, for example, an ammonium chloride solution, or an ammonium sulfate solution, or a solution of maleic acid anhydride. As is known, in itself, from the state of the art, also in the inventive method it is possible to cut the paper layer to format in a fifth stage that precedes in time to the second stage, being the difference to the method of the state of the art. the technique only that the paper layer is cut to format as a rough paper layer. Depending on the desired structure of the coating element to be produced, it is possible to apply, according to the inventive method, only one layer of decorative paper on the visible surface of the substrate plate. In consideration of the deformation problem explained initially, a layer of counter-tensioned paper could be additionally provided on the support surface of the substrate plate. If the substrate plate is provided both on its visible surface and also on its support surface in each case with a paper layer, namely a layer of decorative paper on the visible surface, and a layer of paper of opposite tension in the supporting surface is advantageous according to a further development of the invention, since it saves time, if the first stages of application of the respective resin on the respective surface or / and the second steps of applying the respective paper layer on the respective surface provided with resin or / and the third steps of pressing together of the respective paper layer with the substrate sheet are performed essentially simultaneously. In addition, it is further possible, by virtue of the wear and erosion problems initially described, to provide on the visible side of the substrate plate still a layer of coating paper on top of the decorative paper layer. In this case, the amount of resin applied in the first stage on the visible surface of the substrate plate can be dosed in such a way that it reaches to soak, respectively, impregnate at the juncture by pressing the paper layers with the substrate plate on the substrate. The third stage of the method for soaking, respectively, is to impregnate both the decorative paper layer and the coating paper layer. Additionally, it is possible, if the substrate plate has been provided on its visible surface both with a decorative paper layer, as well as with a coating paper layer, performing essentially simultaneously the second steps of applying both layers of paper to the substrate. visible surface of the substrate plate provided with resin or / and in the third step of pressing together both layers of paper with the substrate plate. As mentioned in the beginning, the resin can be an aminoplast resin, preferably a urea resin or a melamine resin, or a mixture of urea resin and melamine resin. The resin may also contain, in particular to impregnate the paper layers provided on the side of the visible surface, at least one substance that increases the erosion resistance, for example corundum. It should still be noted that each layer of paper, i.e., the decorative paper layer or / and the opposing traction paper layer or / and the coating paper layer, can be formed by a multiplicity of layers of paper. If desired, the coating element produced in this way can be subjected to a surface treatment. For this purpose, the surface of the decorative paper layer, respectively, if applicable, is applied to the surface of the coating paper layer, firstly to a surface treatment. This surface treatment may comprise a chemical treatment, for example, the application of an adhesion agent and / or a fluorination, or / and a mechanical treatment, for example, a light grinding of the surface, or / and an electrical treatment, for example, a corona treatment or / and a plasma treatment. A layer of lacquer can then be applied to the surface thus treated and dried. If desired, it is possible to repeat this lacquer application also several times, if necessary accompanied by a new pretreatment of the surface of the newly applied lacquer layer. As an adhesive agent, for example, the product "Hydrohaftgrund E643" marketed by Cia. Henelit, Villach, Austria, or organofunctional silane. The organofunctional silanes are hybrid compounds with a reactive organic group and an inorganic alkyl silicate in which both the organic functional group, as well as the hydrolysable inorganic alkoxy group can be adjusted for the respective impregnation resin, respectively, the aminoplast resin, and the lacquer used, to achieve favorable adhesion agency characteristics. In fluorination, the decorative paper layer, pressed together with the substrate plate and soaked with resin, can be treated in a vacuum reactor. After evacuating and inerting the reactor, that is to say, after removing contaminations which are still adhered to or bonded to the surface of the reactor, for example by washing with inert gas, heating the reactor or similar measures, fluorine and gas are deliberately added. inert, being able to use a variable concentration profile of the fluorine mixture to achieve optimal results. Then the reactor is evacuated, washed and the layer of decoration paper can be removed. This so-called out-of-line fluoridation can be integrated as a treatment method after each production process. Fluoridation improves the surface tension and therefore the surface wetting by a lacquer. In addition a polar surface is achieved, which produces a better adherence of a lacquer layer. In a corona treatment, the air that is located in the interstice between two electrodes is ionized. These ions then penetrate, as a function of their kinetic energy, into the surface of the decorative paper layer to be treated, located between the electrodes, namely, for example, to a depth of 10 μm. The physical and chemical changes caused by this on the surface of the decorative paper layer to be treated can not yet be explained univocally. It is assumed, however, that both the oxidation processes on the surface have a role, as well as physical and chemical changes of the surface due to the impact of accelerated ions and electrons. But it is a fact assured by science that a corona treatment causes an improved adhesion of the surface, so that a layer of applied lacquer adheres better on a layer of decorative paper treated in this way. Similar effects are also achieved by a plasma treatment, not taking advantage in this case for the surface treatment of the direct electric light arc, which arises in the electrodes exposed to high voltage, but is generated by charge separation a jet of reactive particles, free of ionized air potential and Orient against the surface of the decorative paper layer to be treated. By means of a corresponding polishing of the surface with such a subsequent, in particular lacquered, treatment, it is possible to achieve in a simple manner any characteristic of desirable surface reflection, of a matt gloss up to a strong gloss. In particular, on a polished surface with a strong gloss, it is not possible to differentiate between a cladding element whose decorative paper layer is printed with a wooden decoration made of real wood. The invention is explained in more detail below with reference to the attached figures 1 to 3 by means of an exemplary embodiment. FIG. 1 is a schematic flow diagram of one embodiment of the inventive method; Fig. 2 a view similar to Fig. 1 of a production method according to the state of the art; and Fig. 3 a schematic representation for explaining the layer structure of a coating element to be produced following the inventive method. Referring to Fig. 1, an inventive method for the production of a cladding element 10 having the structure already explained at the beginning with reference to Fig. 3 is explained, that is, it is provided in particular with a 12a surface visible with a layer 14 of decorative paper and a layer 20 of cover paper, and on its support surface 12b with a layer 18 of opposite stretch paper. As shown in Fig. 1 the layer 14 of decorative paper is enlisted in a step D as raw paper and cut to a size adjusted to the dimensions of the substrate plate 12. In a DL stage the decorative paper layer 14 is then fed to an intermediate tank 22 where it is stored until further processing. In an analogous manner, the layers 18 of opposite traction paper, respectively, layers 20 of coating paper prepared in stages R, respectively, O, analogous to stage D, in RF stages, respectively, OF, in analogues to the stage DF, and are fed in stages RL, respectively, OL, analogous to the stage DL, to a deposit 24, respectively, 26 intermediate. Unlike the method of the state of the art initially explained, the papers stored in the intermediate tanks 22, 24 and 26 are not impregnated with resin. This completely avoids the problem, which arises in known methods, that maximum intermediate storage durations derived from the drying time of the resin have to be taken into consideration. In the inventive method a substrate plate 12, enlisted in stage B, is provided in a BID stage on its visible side 12a with a layer of impregnation resin, more precisely, with a layer of a mixture of impregnating resin and hardener . If required, the substrate plate 12 can also be provided on its rear face, ie on the support surface 12b in a BIR stage with an analogous layer. As an alternative, the steps BID and BIR can also be separated, in each case, in steps BHD and BAD, respectively, BHR and BAR that are carried out at a distance in time, which is insinuated in FIG. 1 by means of arrows with interrupted line. In the steps BHD and BHR, the rear face 12b of the substrate plate 12, a hardener necessary to harden the impregnation resin, is first applied on the visible side 12a, respectively, and the application, per se, of the the impregnation resin. This last variant of the method is an advantage in consideration of the pot time problem of a mixture of impregnation resin and hardener. The BID and BIR steps, respectively BHD and BHR, and the BAD and BAR steps may preferably be performed essentially simultaneously. The substrate plate 12, coated on its two surfaces 12a, 12b with resin, is transported in a step BS to a stacking step in which a layer 14 of decorative paper is placed on the visible side 12a of the substrate plate 12, fed in a DS stage, and a layer 20 of coating paper fed in an optional OS stage, as well as additionally on the support face 12b of the substrate plate 12 a layer 18 of counter-tensioned paper, fed in a step of RS feed. The stack thus formed is conveyed in an HP step to a hot stamping press 28 in which the different layers of paper are bonded to the substrate plate 12 with an increased pressure and an increased temperature. In particular, during this pressing step the resin applied on the substrate plate 12 in the different layers of paper, and soaks them, respectively, impregnates them. A cladding element 10 is thus obtained having the sheet metal structure shown in Fig. 3. The cladding element 10 can then be subjected to., thus produced, still at a surface finishing stage. For this purpose, the surface 14a of the decorative paper layer, respectively, optionally the surface 20a of coating paper 20 is applied, firstly to a surface treatment. This treatment can comprise a chemical treatment, for example, a light grinding of the surface, and / or an electrical treatment, for example, a corona treatment and / or a plasma treatment. On the surface, thus prepared, a lacquer layer 30 can then be applied and dried, which is implied in FIG. 3 only with an interrupted line. If desired, it is also possible to repeat this lacquer application several times, if necessary with a pretreatment of the surface of the newly applied lacquer layer. According to an exemplary embodiment, the surface treatment comprises firstly the application of an adhesion agent, for example, the product "Hydrohaftgrund E643" marketed by the company Henelit, Villach, Austria, and in amounts of between about 5 g. / m and approximately 30 g / m. This adhesion agent is then hardened by UV radiation. In order to further improve the adhesion strength of the subsequent application of lacquer, the surface can be rectified, if desired. The lacquer can be applied in the form of spray lacquer or spray lacquer. As a lacquer, for example, a polyurethane lacquer or a UV lacquer can be used, as well as the "UV Hydro brillant" lacquer marketed by Cía. Henelit, Villach, Austria. The lacquer application can be carried out in an amount of between about 15 g / m2 and about 30 g / m2 and between about 5 g / m2 and about 10 g / m2 for the subsequent lacquer layers. To increase the erosion resistance of the lacquer layer an appropriate additive, for example corundum, can be mixed, preferably in an amount of about 5 g / m2 to about 50 g / m2. Provided that the erosion resistance of the lacquer layer thus applied is sufficient, the use of a coating paper can be dispensed with. Since the lacquer layer does not produce additional stresses on the visible face 12a of the veneer structure applied to the substrate plate 12, it is not necessary to take particular measurements on the rear face 12b of the substrate plate 12 in the paper layer 18 of contrary traction.

Claims (17)

1. Method for the production of a coating element, for example, of a floor panel, a wall covering element, a visible front furniture element, or the like, the covering element comprising a substrate plate which is provided on two surfaces, namely, its visible face and its supporting face opposite to the visible face, in each case with a layer of paper soaked in resin, characterized in that the resin is applied in a first stage on the surfaces of the substrate plate, because it is placed in a second stage, which follows the first stage temporarily, the paper layers on the surfaces of the substrate plate and because it is pressed together substantially simultaneously in a third stage, that follows in a temporal sense to the second stage, the substrate plate provided on the surfaces with resin and the two layers of paper, both layers of paper being soaked in this only up to the third stage with the resin.

Method according to claim 1, characterized in that a hardener, necessary for hardening the resin, is applied in a first step together with the resin on the surface of the substrate plate, preferably a mixture of resin and hardener.

3. Method according to claim 1, characterized in that a hardener, necessary to harden the resin, is applied separately from the resin, preferably in a fourth step above, in a temporal sense, the first stage, on the surface of the substrate plate .

Method according to one of claims 1 to 3, characterized in that the format of the paper layer is adjusted in a fifth stage that precedes, in a temporal sense, the second stage.

Method according to one of claims 1 to 4, characterized in that it is carried out, in case the substrate plate is provided both on its visible face and also on its support face respectively with a paper layer, essentially simultaneously the first steps of applying the respective resin on the respective surface and / or the second step of placing the respective paper layer on the respective surface provided with resin and / or the third step of pressingly bonding the respective paper layers with the substrate plate.

Method according to one of claims 1 to 5, characterized in that it is applied, in case the substrate plate is provided on its visible face both with a decorative paper layer and also with a coating paper layer, in the first stage a quantity of resin on the visible side of the substrate plate that is dimensioned in consideration of both layers of paper.

Method according to one of claims 1 to 6, characterized in that it is carried out, in case the substrate plate is provided on its visible face both with a decorative paper layer and also with a coating paper layer, essentially in simultaneously the second steps of placing the two layers of paper on the visible face of the substrate sheet provided with resin and / or the third steps of pressing together the two layers of paper with the substrate sheet.

8. Method according to one of claims 1 to 7, characterized in that the resin is an aminoplast resin, preferably a urea resin or a melamine resin, or a mixture of urea resin and melamine resin.

9. Method according to one of claims 1 to 8, characterized in that the resin contains at least one substance that increases the resistance to erosion, for example, corundum.

Method according to the general concept of claim 1 and, if desired, the feature of one of claims 1 to 9, characterized in that a visible surface of the decorative paper layer or the coating paper layer is first subjected to at least one surface treatment, and because at least one layer of lacquer is then applied to this treated surface.

11. Method according to claim 10, characterized in that the at least one surface treatment comprises a chemical treatment.

Method according to claim 11, characterized in that the at least one surface treatment comprises the application of an adhesion agent, for example, organofunctional silane, or fluorination.

Method according to one of claims 10 to 12, characterized in that the at least one surface treatment comprises an electrical treatment.

Method according to claim 13, characterized in that the at least one surface treatment comprises a corona treatment or a plasma treatment.

15. Method according to one of claims 10 to 14, characterized in that the at least one surface treatment comprises a mechanical treatment.

16. Method according to claim 15, characterized in that the at least one surface treatment comprises a light grinding of the surface. Method according to one of claims 10 to 16, characterized in that the lacquer contains at least one substance that increases the resistance to erosion, for example, corundum.