Floor covering, floor panels, method for their realization

0001This invention relates to a floor covering consisting of hard panels, as well as to floor panels for forming such floor covering, and a method for realizing such floor panels.

0002In particular, it relates to a floor covering formed of laminated panels, also called laminated parquet.

0003It is known that with such laminated parquet, the appearance of wood is imitated by providing the floor panels at their upper surface with a decorative layer printed with a wood pattern, on top of which a transparent layer of synthetic material is provided.

0004Mostly, the printed decorative layer consists of printed paper. Usually, the layer of synthetic material consists of an synthetic resin or one or more transparent or translucent material layers soaked in synthetic resin, in which possibly products can be worked in, in order to enhance, for example, the wear and tear resistance of the final surface.

0005The printed decorative layer and the layer of synthetic material are provided on an underlying basic layer, which can be realized according to different techniques.

0006So, for example, this is possible by soaking the decorative layer in resin and bringing it, after hardening, together with said layer of synthetic material, which then preferably also consists of a thin transparent paper layer also soaked in resin, and together with a basic layer and possible other layers, into a press and compressing it, under the supply of heat, to one hardened whole. This technique is known under the denomination of DPL (Direct Pressure Laminate).

0007Of course, other techniques are possible, too. So, for example, first a top layer may be formed which, amongst others, comprises the aforementioned decorative layer and the layer of synthetic material present thereupon, after which this top layer is attached on a basic layer or basic structure.

0008Also, said basic layer may consist of different materials or material layers. A material often used to this end is MDF (Medium Density Fibre board), HDF (High Density Fibre board), respectively.

0009It is also known that impressions can be realized in the transparent layer of synthetic material, this in order to obtain an imitation of wood pores and other unevennesses which can be present at the surface of real wood. With the known embodiments, this is performed by simply providing a series of impressions in the floor panels, which impressions substantially extend according to one and the same direction. Notwithstanding the use of such impressions, the known embodiments show the disadvantage that the imitation effect still is not optimum. So, for example, they show the disadvantage that, if one looks at such floor panels at a relatively small angle, a light refraction at the transparent layer of synthetic matter is created, as a result of which only a glossy surface can be seen, without any visible effect of the actual print being perceived.

0010<patcit id="pcit0001" dnum="WO0148333A"><text>WO-A-01/48333</text></patcit> is a document falling under Article 54(3) EPC and is therefore not relevant to the question of inventive step. This document addresses problems associated with using decor paper in the manufacture of decorative laminates by printing a decorative pattern directly onto the upper side of the supporting core and then providing the upper side with a protecting wear layer to thereby provide a surface element. The décor side of the surface element may be provided with a surface structure to enhance the realism of the décor.

0011<patcit id="pcit0002" dnum="WO9731776A"><text>WO-A-97/31776</text></patcit> relates to a process for the manufacture of a decorative thermosetting laminate with a décor pattern having décor sections directed in different directions. To provide the décor sections with matching surface structure, <patcit id="pcit0003" dnum="WO9731776A"><text>WO-A97/31776</text></patcit> proposes the use of two or more matrixes provided with surface structure sections which coincide with corresponding décor pattern sections. The laminate thereby gets a décor surface with a surface structure the different directions of which correspond with the directions of the different décor sections of the décor pattern. This document does not propose how to provide a structured floor covering in which the décor pattern extends in a single direction and in which a highly realistic imitation of a wood pattern is attained.

0012The invention aims at a floor covering, and more particularly at floor panels, whereby the top layer has technical characteristics which contribute to a considerable improvement of the imitation of the wood pattern, or at least the visual perception of this wood pattern, and whereby the aforementioned disadvantages of the known embodiments are minimized.

0013To this aim, the invention thus relates to a floor covering as defined in claim 1, consisting of hard panels, with a laminated structure, whereby at least at the upper surface a printed decorative layer with a wood pattern is present, with thereupon a transparent layer of synthetic material in which impressions are formed, with as a characteristic that the impressions substantially follow the wood pattern, with which it is meant that they substantially are provided in function of the wood pattern. Hereby, it is preferred that the impressions follow the wood pattern substantially in longitudinal direction as well as substantially in transverse direction and in directions situated in between.

0014Thereby, a technical solution is offered for letting the printed pattern seem more real, without the necessity of refining the printing technique itself in an expensive manner, which is very important with laminated panels provided with such printed pattern. By having the impressions run not only substantially according to one well-defined direction, then, when a person moves over the floor covering, an effect is obtained that the light incidence moves, as a result of which, so to speak, a living light effect is created. Also, a better depth effect is obtained, and the colours of the printed pattern are better perceptible.

0015As usual with the known laminated parquet panels, the printed decorative layer preferably consists of paper, however, other materials, either on the basis of cellulose or not, are not excluded. Moreover, this decorative layer can be processed in different manners, for example, previous to the application thereof on the underlying basic layer, soaked in a synthetic resin or such.

0016The aforementioned "transparent layer of synthetic material", is sufficiently transparent for perceiving the printed wood pattern. This layer

0017as usual with known laminated parquet panels, consists of one or more transparent or translucent material layers soaked in synthetic resin, for example, very thin transparent layers of paper.

0018In the layer of synthetic material, substances may be present by which the wear and tear resistance of the surface is enhanced.

0019Although the invention aims at impressions which substantially follow the printed wood pattern, it is evident that this inventive idea can be realized in different ways.

0020So, for example, impressions can be applied which are bent or curved and which follow the bent shapes of the wood pattern.

0021Also, opposite to the known embodiments, whereby mostly relatively short impressions are applied, now longer impressions can be applied, for example, with lengths of 3 cm or more, or even over the entire length of a wood nerve.

0022It is noted that by the term "wood pattern", different aspects of such wood pattern can be understood. So, in accordance with the invention, the impressions, or at least a number of the impressions, are provided in function of the course of the wood nerves of the printed wood pattern, however, according to a variant, which can be combined with the preceding, impressions are provided which are applied in function, and more particularly at the location, of the so-called wood pores of the printed wood pattern. Wood pores mostly are dark, often strip-shaped specks in wood, which up to now have been particularly difficult to imitate. In the first place, this problem is pertinent when imitating oak, where often less nerves are present, however, the wood pores are very important. By providing, impressions at the location of these wood pores, the imitated specks will almost have the look of real pores.

0023In the most preferred forms of embodiment, the floor covering, and more particularly each floor panel concerned, will be provided with impressions which are obtained by means of a pressing mould, more particularly pressing plate, the relief of which was realized by means of image-processing technology, starting from a wood pattern, either an image of a wood pattern or a real wood pattern. Hereby, one starts from the same wood pattern than the one of the print of the decorative layer.

0024Of course, the invention also relates to floor panels for realizing the floor covering described in the aforegoing.

0025Further, the invention also relates to a method for realizing such floor panel, which method is characterized in that the aforementioned impressions are applied in said layer of synthetic material by means of a pressing mould, more particularly a pressing plate. Of course, the pressing plate is provided with a relief, more particularly protruding parts, such that impressions are formed which, as aforementioned, follow the printed wood pattern and/or are realized in function of this wood pattern.

0026Preferably, hereby use is made of a pressing mould, more particularly a pressing plate, the relief of which was realized by means of image-processing technology, starting from a wood pattern, either an image of a wood pattern or a real wood pattern. By realizing said relief by means of image-processing, a true copy is obtained. More particularly, for forming, on one hand, the pressing plate and, on the other hand, the patterns to be printed, it is started from one and the same wood pattern, with the advantage that the relief and the printed pattern can be perfectly attuned to each other.

0027Of course, the results obtained by image-processing can be processed further.

0028It is also not excluded to determine the locations where the impressions have to be realized and therefore also the relief of the pressing plate in other ways, for example, by starting from an image of a wood pattern, to determine the locations and shapes of the desired impressions, either by means of or with the support of a computer program.

0029According to the invention, during image-processing, preferably a separation is performed, on one hand, for forming one or more image layers and, on the other hand, for forming one or more structural layers. A separation for image layers already is a known technique and is necessary for being able to print the different colours. According to the invention, now still an additional separation is performed for the aforementioned structural layers, in other words, for forming said relief at the pressing plate or such. To this end, an image of the wood pattern is made and, by means of image-processing technology, an image is formed therefrom which determines the position, and possibly also the depth and the size, of the impressions, after which, by means thereof, a pressing plate is realized, for example, by means of etching techniques or any other technique. It is evident that for the image processing for creating, starting from, for example, the pattern of a real piece of wood, an image which is suitable for forming the relief, different image-processing programs, possibly especially designed to this aim can be applied.

0030Preferably, the floor panels are realized according to the classical technique which is applied for forming DPL (Direct Pressure Laminate), with the only difference that a pressure mould, more particularly, a pressing plate is applied in the usual production press which is provided with a relief by which impressions, such as mentioned in the aforegoing, are formed. As usual, the floor panels hereby are formed from larger plates. These plates are formed by bringing a basic layer, more particularly a base plate, together with the decorative layer and the layer of synthetic material, and possible other layers, in a heated press and compressing them to a whole, whereby said synthetic resins provide for adhesion and hardening. Simultaneously to pressing, the impressions are applied, as the press, at the surface of the pressing part which comes into contact with the upper side of the aforementioned plate, is provided with said pressing plate comprising the relief which is necessary for applying impressions in accordance with the invention.

0031Preceding the pressing, according to the present invention, preferably a positioning is performed between, on one hand, the decorative layer and, on the other hand, the applied pressing plate, in order to position the printed pattern on the decorative layer and the pattern present at the pressing plate over each other.

0032Practically, the positioning preferably is performed by shifting the base plate, together with the decorative layer and layer of synthetic material present thereupon, until they obtain the desired position.

0033The aforementioned positioning may be performed in different manners, however, it can be realized in a particular manner by performing such positioning by means of one or more marks provided on the decorative layer.

0034With the intention of better showing the characteristics of the invention, hereafter, as an example without any limitative character, several preferred forms of embodiment are described, with reference to the accompanying drawings, wherein: <ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">figure 1</figref> schematically represents a part of a floor covering which is composed of panels according to the invention;</li><li><figref idref="f0001">figure 2</figref> represents a panel of the floor covering from <figref idref="f0001">figure 1</figref> in plan view;</li><li><figref idref="f0001">figures 3 and 4</figref> represent cross-sections according to lines III-III and IV-IV in <figref idref="f0001">figure 2</figref>, respectively;</li><li><figref idref="f0002">figure 5</figref>, at a larger scale, represents a cross- section according to line V-V in <figref idref="f0001">figure 1</figref>;</li><li><figref idref="f0002">figure 6</figref>, at a larger scale, represents a cross- section according to line VI-VI in <figref idref="f0001">figure 1</figref>;</li><li><figref idref="f0003">figure 7</figref>, at a larger scale, represents the part indicated by F7 in <figref idref="f0002">figure 6</figref>;</li><li><figref idref="f0003">figure 8</figref> represents a view analogous as in <figref idref="f0003">figure 7</figref>, but whereby the panels are shifted towards each other substantially in one and the same plane;</li><li><figref idref="f0003">figure 9</figref>, in cross-section, represents another panel according to the invention, with bevels provided with a print;</li><li><figref idref="f0003">figure 10</figref> schematically represents how the print in the embodiment of <figref idref="f0003">figure 9</figref> can be provided;</li><li><figref idref="f0004">figure 11</figref> schematically represents a cross-section according to line XI-XI in <figref idref="f0003">figure 10</figref>;</li><li><figref idref="f0004">figure 12</figref>, at a larger scale, represents the upper surface of a floor panel according to the invention, in particular the part indicated by F12 in <figref idref="f0001">figure 2</figref>;</li><li><figref idref="f0004">figure 13</figref> represents a cross-section according to line XIII-XIII in <figref idref="f0004">figure 12</figref>;</li><li><figref idref="f0004">figure 14</figref> schematically represents how plates can be realized from which floor panels according to the invention can be formed.</li></ul>

0035As represented in <figref idref="f0001">figures 1 and 2</figref>, the invention relates to a floor covering 1, as well as to hard panels, more particularly floor panels 2, from which such floor covering 1 is assembled, whereby these floor panels 2, at their top side 3 or decorative side, are provided with a top layer 4 with a printed wood pattern 5.

0036In the represented example, the floor panels 2 are rectangular, however, it is clear that they, according to not-represented variants, also can have another shape, for example, can be square or polygonal.

0037Preferably, the floor panels 2, at least at two opposite edges 6-7, and even better, as represented in <figref idref="f0001 f0002 f0003">figures 2 to 8</figref>, at both pairs of edges 6-7, 8-9, respectively, are provided with coupling means 10, by means of which several of such floor panels 2 mutually can be coupled, such that these coupling means 10 provide for a locking according to a direction R1 perpendicular to the plane of the floor covering 1, as well as in a direction R2 perpendicular to the edges 6-7 and/or 8-9 concerned and parallel to the plane of the floor covering 1.

0038Hereby, such coupling means 10 can be realized such that the different floor panels 2 mutually can be coupled by means of translation movements T1 and/or T2 and/or pivoting movements W1, such as indicated in <figref idref="f0001">figure 1</figref>, as well as made clear in <figref idref="f0002 f0003">figures 6 to 8</figref>.

0039Such coupling means 10 which allow a glue-free mutual coupling of the floor panels 2, as well as an uncoupling thereof, are already known in themselves from the international patent application <patcit id="pcit0004" dnum="WO9747834A"><text>WO 97/47834</text></patcit>.

0040It is noted that the present invention, however, is not limited to floor parts with coupling means 10 which provide for a mechanical locking in the directions R1 and R2, but in fact also can relate to floor panels which are provided with other coupling means, for example, with a classical tongue and groove which can be glued into each other, or even to floor panels comprising no coupling means at all.

0041Besides, the floor panels 2 either can be provided with additional particularities or not, such as bevels 11 at the upper edges, for example, such as represented in <figref idref="f0001 f0002 f0003">figures 3 to 10</figref>, on which, as specifically illustrated in <figref idref="f0003">figures 9 and 10</figref>, either a decorative layer 12 is provided or not, for example, by means of transfer printing, whereby, such as schematically represented in <figref idref="f0003">figures 10</figref> and <figref idref="f0004">11</figref>, a print layer 13, which is present on a carrier, is transferred to the surface of the bevels 11, for example, by means of a heated pressing roll 15.

0042The actual invention to which the present application is relating, is represented schematically in <figref idref="f0004">figures 12 and 13</figref>.

0043The particularity thereby consists in that at the top side of the floor panels 2, a decorative layer 16 is present, with thereover a transparent layer of synthetic material 17, in which impressions 18A-18B-18C are formed. Hereby, the decorative layer 16 and the layer of synthetic material 17 are of the kind as described in the introduction and together form the top layer 4 indicated schematically in <figref idref="f0001 f0002 f0003">figures 3 to 10</figref>.

0044According to the invention, the impressions 18A-18B-18C follow the printed wood pattern 5, preferably substantially in longitudinal direction as well as substantially in transverse direction and in directions situated in between.

0045As represented in <figref idref="f0004">figure 13</figref>, the impressions 18A-18B-18C preferably only extend up to such a depth that they are situated above the printed decorative layer 16.

0046As indicated by 18A and 18C, the impressions may consist of successive short impressions, or, as represented by 18B, of longer, uninterrupted, possibly bent impressions. Of course, other designs are not excluded. However, it is important that the location and/or shape of the impressions is in function of the wood pattern 5, with which it is meant in the first place that these impressions are realized in function of the wood nerves and possibly additionally in function of the wood pores.

0047In the case of short impressions, these, such as indicated by 18A, can be directed with their length according to the printed wood nerve 19 or, as indicated by 18C, also be directed with their longitudinal direction otherwise, however, positioned such that their configuration globally follows the wood nerve 19.

0048It is noted that the three possibilities of impressions 18A-18B-18C represented in <figref idref="f0004">figure 12</figref> are not limitative. Also, these will normally not be applied in combination with each other, but one well-defined type 18A or 18B or 18C or another configuration will be used.

0049In <figref idref="f0004">figure 14</figref>, a form of embodiment of the method for realizing said floor panels 2, described in the introduction, is represented schematically.

0050As represented, the impressions concerned, for example 18A and/or 18B and/or 18C, hereby are formed by using a pressing mould, more particularly a pressing plate 20, which, at the side intended for coming into contact with the products to be treated, is provided with a suitable relief 21.

0051First, during production, large plates are manufactured, from which several floor panels 2 can be formed, more particularly can be sawn therefrom, which subsequently can be provided with coupling means 10, for example, by means of a milling treatment.

0052For forming said plates, as schematically represented in <figref idref="f0004">figure 14</figref>, at least a printed decorative layer 16 and a layer of synthetic material 17 are provided on a base plate 22, such in a press 23, after which the whole is compressed by means of the pressing plate 20, preferably while supplying heat.

0053According to the invention, previous to pressing, a positioning is performed between, on one hand, the decorative layer 16 and, on the other hand, the applied pressing plate 20, in order to position the printed pattern on the decorative layer 16 and the pattern present at the pressing plate 20 over each other.

0054In the example, this positioning is performed by shifting the base plate 22, together with the decorative layer 16 and layer of synthetic material 17 present thereon, until the desired position is achieved. This positioning is realized by means of one or more adjustable stops 24 against which the base plate 22, with the decorative layer 16 and layer of synthetic material 17 present thereupon, and possible other layers, is positioned, possibly by means of marks which are applied on the decorative layer 16, which are perceived by means of one or more sensors 25, and whereby, by means of control means 26 and in function of the signals obtained from the sensors, it is provided for the control of driving means 27 of the movable stops 24.

0055Obviously, the positioning can be achieved in the two directions of the plane of the base plate 22.

0056It is evident that, according to a variant, the layer of synthetic material and the decorative layer, already before their application on the base plate, may consist of a single layer, for example, in that the decorative layer is soaked such that sufficient synthetic material is present thereupon in order to form impressions therein. It is also not excluded to start from a layer of synthetic material which is provided with a decorative layer at the underside, which layer is exclusively formed by a print. The term print must be interpreted in the broadest sense, and thereby any technique is intended with which an image of a wood pattern can be realized.

0057Also, other layers may be taken up in the top layer, such as, for example, a layer of white paper, also impregnated with resin, which is provided under the decorative layer, which has the purpose of forming a neutral underground.

0058The present invention is in no way limited to the forms of embodiment described as an example and represented in the figures, on the contrary may such floor covering, and more particularly said panels, as well as said method, be realized in different variants without leaving the scope of the invention as defined by the appended claims.