Panel and Methods for Manufacturing a Panel

The present invention relates to a panel with an alternative top layer, such as with an alternative decorative and/or wear-resistant layer, as well as to methods for the manufacture thereof.

In particular, the invention relates to a panel comprising a substantially plate-shaped core or substrate, such as a polymer core, and a decorative, wear-resistant layer, wherein said decorative, wear-resistant layer is bonded at least partially to a surface of said polymer core, as well as methods for manufacturing said panel. Material of this kind is known for example from WO 2019/086566 A1.

Floor coverings that comprise a polymer core, in particular based on polyvinyl chloride (PVC), also known as vinyl floors or as LVT (Luxury Vinyl Tiles), have a number of various advantages that make them very suitable for use in living spaces. Thus, they have good hygienic properties, they are very functional and comfortable, and it is possible to provide these floor coverings with printed finishing layers, for example with a wood pattern. These floor coverings are manufactured in thicknesses of approx. 5 mm and can be glued to the substrate. Moreover, PVC panels are also known that are suitable, by means of click profiles, for glueless, floating placement. With respect to laminate floors for example, the advantage of PVC floors is that they are moisture-resistant, feel more comfortable and have significantly better properties relating to sounds from contact and walking.

However, to ensure an acceptable quality and life of these floor coverings, they generally comprise one or more additional layers that increase the comfort and/or the wear resistance further. WO 2018/087637 A1 discloses for example a floor panel with a substrate or core comprising a polymer material, for example PVC, and a separate decorative layer and wear-resistant layer provided thereon. This floor panel with a core of polyvinyl chloride (PVC) may in addition comprise fillers. The addition of fillers in such floors is also known from WO 2019/086566 A1. A plate material of this kind is called SPC (Stone Plastic Composite). The plate material produced by this process is largely dimensionally stable and water-resistant, and has a high specific gravity. It ensures a pleasant sound of walking and is hard enough to compensate for irregularities in the subfloor or to prevent them “by telegraphing”, furthermore it is stable enough to carry out edge profiling and to join several panels together without glue by means of so-called “click profiles”.

Each of the floor coverings and/or floor panels discussed have the feature in common that they preferably make use of a wear-resistant layer, which increases their quality and life. In practice, a first laminated layer then generally provides the decorative finish, and a second laminated layer provides the wear resistance. However, it therefore follows that the production process is quite complex and that often specific conditions are imposed on the decorative and/or wear-resistant layer, in particular the decorative possibilities are quite limited and they are generally applied in the form of a laminated film, which is often perceived as an imitation. Because of its thickness, and its incomplete transparency, the wear layer may be detrimental to the quality of the decor.

The invention aims firstly to provide an alternative panel, wherein according to various preferred embodiments, a solution can be obtained for the problems relating to the decorative and/or wear-resistant layer as described above. Some embodiments of the invention aim in addition to provide imitations for existing tile products that are of good quality but are easier or more practical for handling and/or placement, such as concrete tiles, particularly grit-filled concrete tiles. The invention also aims to provide a good-quality imitation of the appearance of related PVC-based products, such as the so-called compact vinyl tile (CVT).

For this purpose, according to its first independent aspect, the invention relates to a panel comprising a substantially plate-shaped polymer core and a top layer, preferably a decorative and/or wear-resistant layer, wherein said decorative and/or wear-resistant layer is bonded at least partially to and/or in a surface of said polymer core, wherein said decorative and/or wear-resistant layer comprises a granular and/or fibrous material. By using said granular and/or fibrous material that is bonded at least partially to and/or in a surface of the polymer core, there is no longer the need to apply a separate decorative film, or a separate wear-resistant film, on the panel. The invention as described herein namely allows the panel to be provided with an innovative decorative layer that may inherently possess wear-resistant properties.

In the sense of the present invention, the term “panel” means a plate-shaped material, said plate-shaped material being available both in cut form, for example cut to measure, and in uncut form. In particular, reference is made herein to, among others, Luxury Vinyl Tiles (LVT), Stone Polymer Composite (SPC), or other polymer-based panels.

The terms “decorative layer” and “wear-resistant layer” mean, in the sense of the present invention, a single, i.e. unassembled, layer, which provides the panel with a decor, or with wear-resistant properties. Thus, known decorative layers provide a panel for example with a wood grain pattern or with coloring that imitates stone. Said layer extends in particular over an approximately horizontal region of the panel and preferably through a substantial thickness of the panel. This layer is possibly a uniform, continuous layer, for example an extruded polymer layer, or comprises an assembly of material zones that extend continuously in the approximately horizontal region of the panel, as is the case when using separate particles, for example grit. In the prior art, a decorative layer is generally applied on a substrate or core, and the decorative layer is provided in its turn with a wear-resistant layer. According to the present invention, however, the granular and/or fibrous material provides both properties simultaneously. Consequently, application of additional and/or separate wear-resistant layers is possible, but superfluous.

In the sense of the present invention, the term “granular material” means a material that comprises separate particles. Various terms may be used, depending on the order of magnitude of these separate particles. In particular, “granular” is a more general term, i.e. covering a wide range of order of magnitude, and in the case of smaller particles reference may be made for example to “pulverulent material”. It is thus apparent that the granular material possibly assumes a natural form, for example in the case of grit, or may be cut, ground or shredded, for example in the case of polymer granules. The particle size of the granular material can be measured by various techniques from the prior art. In particular, for larger granules the particle size may possibly be determined by means of sieving techniques. The particle size of smaller particles may possibly be determined by laser granulometry, a technique that is carried out in accordance with ISO 13320. This relates to a dynamic light scattering technique using a laser with an emission wavelength of 632.8 nm, measurement being effected at a scattering angle of 90 degrees. This technique may for example be carried out with a Malvern® Mastersizer 2000 or with a Malvern® Mastersizer 3000. For carrying out the measurement of particle size distribution, the respective particles may be dispersed in a liquid, such as water.

According to a preferred embodiment, the granular and/or fibrous material is selected from the group of stone, grit, gravel, quartz, aluminum oxide (AlO), polyvinyl chloride (PVC), synthetic fibers, textile fibers, natural fibers, or combinations thereof. Suitable synthetic fibers are for example nylon or PET fibers. The choice of the granular and/or fibrous material thus allows very varied decoration possibilities, without it being necessary to apply an additional wear-resistant layer or to tailor such a layer specifically to a decorative layer.

It is clear that in the context of the invention, according to its first aspect, a top layer, for example a decorative and/or wear-resistant layer, may be produced that eliminates the need to apply separate and/or additional wear-resistant layers, and that allows very varied decorative possibilities. In contrast to decorative and/or wear-resistant layers as known in the prior art, the granular and/or fibrous material makes it possible to build up a relatively uniform top layer, in particular of substantial thickness, with exceptionally good wear resistance.

According to a further or another embodiment, the granular and/or fibrous material forms a substantially flat and homogeneous scatter layer on and/or in the surface of said polymer core.

In some embodiments the scatter layer or the layer of granular material has a thickness between 0.05 and 10.00 mm, preferably between 0.10 and 8.00 mm, more preferably between 0.50 and 5.00 mm. The scatter layer or layer of granular material is, in each of these embodiments, bonded to and/or in the polymer core, wherein the possibility exists that the scatter layer or the layer of granular material and the polymer core run partially into each other, or that they merely touch each other and so do not run into each other. The scatter layer with a thickness within the range described herein allows the scatter layer to form a relatively uniform decorative and/or wear-resistant layer, wherein the polymer core is only slightly or is not visible through this decorative and/or wear-resistant layer. In some embodiments the granular and/or fibrous material consists of particles with a particle size and/or transverse dimension between 0.05 and 10.0 mm. According to some embodiments, particles with a larger particle size may also be used, wherein a coarser structured surface is obtained. Preferably, the granular and/or fibrous material consists of particles with a particle size and/or transverse dimension between 0.10 and 8.00 mm, more preferably between 0.50 and 5.00 mm. Consequently, relatively uniform spreading of the granular and/or fibrous material over the surface of the polymer core is possible, wherein a structured decorative and/or wear-resistant layer is formed, which differs markedly from for example a flat printed film.

According to some embodiments, the coverage of the granular and/or fibrous material is at least 90%. This means that a perpendicular projection of the granular and/or fibrous material on the surface of the polymer core covers this surface to at least 90%. Preferably, the coverage of the granular and/or fibrous material is at least 95%, more preferably at least 99%.

According to some embodiments, the individual particles of the granular and/or fibrous material have only limited hues, wherein a decor is obtained that is substantially uniform. According to some other embodiments, the individual particles of the granular and/or fibrous material have a number of different hues, wherein they display arbitrary ordering. Yet other embodiments relate to those in which the individual particles of the granular and/or fibrous material have a number of different hues, and wherein their ordering follows a pattern. It is thus clear that the decorative possibilities of the decorative and/or wear-resistant layer as described herein are very varied. According to yet another possibility there is printing or other coloring on the granular and/or fibrous material. This printing or coloring may be continuous over substantially the whole surface of the respective panel or may be interrupted.

Although the present invention eliminates the need for separate and/or additional wear-resistant layers, it is possible to apply said layer on top of the granular and/or fibrous material. Possibly said additional wear-resistant layer relates to a wear-resistant film, or a transparent varnish coat applied in liquid form, or printing or coloring as stated above.

With the same aim as in the first aspect, according to an independent second aspect the present invention relates to a panel comprising a substantially plate-shaped polymer core and a top layer, such as a decorative and/or wear-resistant layer, wherein said decorative and/or wear-resistant layer is bonded at least partially to the surface of said polymer core, particularly wherein the thickness of said decorative and/or wear-resistant layer and the thickness of said polymer core are in a ratio between 1:5 and 5:5. The advantage of this is that the top layer or decorative and/or wear-resistant layer has an inherent wear resistance, wherein the need for the application of separate and/or additional wear-resistant layers is eliminated. The decor of the top layer or decorative and/or wear-resistant layer now extends through a substantial thickness, so that the decor remains intact, even though this layer will display wear after a certain time. This contrasts with the decorative films known from the prior art, wherein slight damage of the decorative film may already reduce the quality of the decor drastically, hence the need for a separate and/or additional wear-resistant film. However, the top layer or decorative and/or wear-resistant layer of the second aspect provides a decor that extends both in the surface of the panel, and perpendicular to the surface of the panel. The decor is thus also visible along any saw cuts, or where the decorative and/or wear-resistant layer is damaged locally and/or on the surface. Preferably, the ratio of the thickness of the top layer or decorative and/or wear-resistant layer to the thickness of the polymer core is between 2:5 and 4:5

According to a preferred embodiment, the polymer material of the top layer or decorative and/or wear-resistant layer is an extruded polymer material. This extruded polymer material can be fastened to the polymer core by regular techniques, which include heat lamination or gluing, and the two layers may possibly be coextruded. The use of an extruded polymer material has the further advantage that any coloring matter can be incorporated directly in the polymer material to be extruded, thus determining the appearance of the decor directly.

According to another preferred embodiment, the polymer material of the top layer or decorative and/or wear-resistant layer is a scattered polymer material. This scattered polymer material may be bonded to the polymer core by regular techniques, for example by heating and/or pressing.

According to some embodiments, the polymer material of the top layer or decorative and/or wear-resistant layer comprises one or more colorants. The colorants are then distributed over the polymer material as uniformly as possible, or may be dosed specifically so that certain hues are obtained. The dosage of the one or more colorants thus determines the decor of the decorative and/or wear-resistant layer.

According to some embodiments as described in the first and/or second aspect of the invention, the polymer core is an extruded polymer core.

In some embodiments, the polymer core and/or the polymer material of the top layer or decorative and/or wear-resistant layer comprises one or more polymers from the group of modified or unmodified polyolefins, for example polyethylene, polypropylene, polyvinyl chloride, or copolymers thereof.

Preferably, the polymer core and/or the polymer material of the top layer or decorative and/or wear-resistant layer comprises polyvinyl chloride (PVC). Preferably, in the case of the top layer, the polyvinyl chloride has a concentration of at least 95 wt %, more preferably at least 99 wt %, most preferably 100 wt %. Preferably, in the case of the polymer core, the polyvinyl chloride has a concentration of at least 20 wt %.

It is possible that the polymer core further comprises one or more fillers selected from the group of inorganic fillers, such as chalk, lime and/or talc, or organic fillers, such as wood, bamboo and/or cork, and/or mineral fillers.

According to a further or another embodiment, the polymer core and/or the polymer material of the top layer or decorative and/or wear-resistant layer comprises polyvinyl chloride (PVC) and calcium carbonate (CaCO) as filler.

Preferably, the polymer core and/or the polymer material of the top layer or decorative and/or wear-resistant layer comprises one or more additives selected from the group of Ca/Zn stabilizers, impact strength modifiers, waxes, or combinations thereof.

According to some embodiments, the calcium carbonate (CaCO) has a concentration of at most 80 wt % and the polyvinyl chloride (PVC) has a concentration of at least 20 wt %, wherein these concentrations may be employed in the polymer core and/or in the top layer. Preferably, the calcium carbonate (CaCO) has a concentration between 10 and 80 wt % and the polyvinyl chloride (PVC) has a concentration between 20 and 90 wt %. More preferably, the calcium carbonate (CaCO) has a concentration between 60 and 80 wt % and the polyvinyl chloride (PVC) has a concentration between 20 and 40 wt %. It was found that a particularly good result is achieved when the proportion of calcium carbonate is greater than the proportion of PVC. Preferably, the calcium carbonate (CaCO) has a concentration between 65 and 80 wt % and the polyvinyl chloride (PVC) has a concentration between 20 and 35 wt %. More preferably, the calcium carbonate (CaCO) has a concentration between 70 and 80 wt % and the polyvinyl chloride (PVC) has a concentration between 20 and 30 wt %. Most preferably, the calcium carbonate (CaCO) has a concentration of 75 wt % and the polyvinyl chloride (PVC) has a concentration of 25 wt %.

Of course, any proportion of additives should be taken into account. According to some embodiments, the concentration of the additives is at most 5 wt %.

In the sense of the present invention, it is to be understood in particular that the panel according to the preceding embodiments is free from resins, adhesives and/or glues between the polymer core and the decorative and/or wear-resistant layer. The bond between the various layers may thus be achieved unequivocally by the polymer material of the polymer core. Alternatively, however, one or more materials may be applied between the polymer core and the decorative and/or wear-resistant layer. Thus, for example, a layer of a flexible polymer, for example a layer that contains PVC and plasticizer, for example 15 phr plasticizer or more, may be provided on the surface of the polymer core facing the top layer. Said layer may have a favorable influence on embedding of a granular material or a fibrous material, and may also have a positive effect on walking comfort and the sound of walking.

The panel as described in each of the various embodiments is preferably a floor board or floor panel, a ceiling board or ceiling panel, or a wall board or wall panel.

In a further or another embodiment, the invention also envisages that the panel as described herein can be placed easily, wherein the risk of errors in laying, or of gaps between the placed boards or panels, is minimized. According to some embodiments, the invention envisages that the panel as described herein excludes or at least optimally counteracts the formation of any gaps or cracks. To this end, the invention relates to a board or panel according to one of the embodiments described above, wherein at the edges of two sides located opposite each other, the panel is provided with interacting coupling parts, substantially in the form of a tongue and a groove. These coupling parts are provided with integrated mechanical locking means, which prevent the moving of two coupled boards or panels apart in a direction perpendicular to the respective edges and parallel to the underside of the coupled floor panels. Preferably, these coupling parts are shaped in such a way that they allow any clearance between the boards or panels to be minimized, or more preferably excluded. In particular, for this purpose the coupling parts comprise an upper lip and a lower lip, which delimit the groove, and the tongue is a tongue-shaped element.

“Integrated mechanical locking means” is to be understood to mean that these form a fixed component of the boards or panels, either by being bonded rigidly to the boards or panels, or by being formed in one piece therewith. In one embodiment, the coupling parts are provided with locking means, which, in the coupled state of two or more of such boards or panels, exert a clamping force on each other, which forces the panels, for example floor panels, together. The result is that not only the formation of gaps is counteracted during application, but also the development of gaps at a later stage is counteracted.

According to some embodiments, the coupling parts are made in one piece with the polymer material of the polymer core of the panel, but not with the top layer or decorative and/or wear-resistant layer. This is for example the case when a coarse granular material is used as decorative and/or wear-resistant layer, such as grit. According to some other embodiments, the coupling parts are made in one piece with both the polymer material of the polymer core and with the polymer material of the top layer or decorative and/or wear-resistant layer. In some embodiments, the contact surface, more particularly the horizontally active contact surface on the sealing face of the panels, between the tongue-shaped element and the upper lip, is formed by the polymer material of the polymer core, and the top layer or decorative and/or wear-resistant layer is only present on a horizontal level above this contact surface. In some other embodiments, the contact surface, more particularly the horizontally active contact surface on the sealing face of the panels, between the tongue-shaped element and the upper lip, is formed by the polymer material of the top layer or decorative and/or wear-resistant layer, wherein a completely seamless decor is possible.

According to some embodiments, a part of the upper lip is formed by the top layer or decorative and/or wear-resistant layer, so that a continuous decor is possible between successive panels. According to some other embodiments, the granular material may partially cover and thus camouflage any seam between successive panels.

According to some embodiments, at least 10% of the thickness of the upper lip is formed by the polymer material of the top layer or decorative and/or wear-resistant layer. Preferably at least 20% of the thickness of the upper lip is formed by the polymer material of the top layer or decorative and/or wear-resistant layer, more preferably at least 40%, at least 60%, most preferably at least 80%.

According to some embodiments, said design of the coupling parts consists in that the panel has the following combination of properties: that the coupling parts and locking means are made in one piece with the polymer material of the polymer core and/or polymer material of the decorative and/or wear-resistant layer; that the coupling parts have a form such that two successive boards or panels may be fastened together exclusively by clicking into each other and/or turning, wherein each successive panel can be coupled sideways in the preceding one; that the coupling parts ensure clearance-free locking in all directions in the plane that is perpendicular to the aforementioned edges; that any difference between the upper lip and the lower lip of the lips that delimit the aforementioned groove, measured in the plane of the floor panel and perpendicular to the longitudinal direction of the groove, is less than 1×the total thickness of the panel; and that the total thickness of each related panel is greater than or equal to 4 mm or is greater than or equal to 5 mm.

In particular, when the coupling parts provide clearance-free locking, and these coupling parts are made from one piece from the polymer material of the polymer core and/or top layer or decorative and/or wear-resistant layer of the panel, a perfect join between adjacent floor panels can always be guaranteed, even in repeated expansion and contraction of the floor surface, for example under the effect of temperature changes.

This combination of properties may or may not be combined with the aforementioned property that stipulates that the locking means exert a clamping force on each other. According to a further or another embodiment, the properties of which may or may not be combined with the properties of the embodiments described above, the panel is characterized in that the lower lip, which delimits the underside of the groove, reaches farther than the upper lip; that the locking means are formed from at least one portion that slopes inwards; and that this portion is located, at least partially, in the portion of the lower lip that extends beyond the upper lip.

A third aspect of the present invention relates to a method for manufacturing an extruded, preferably decorative, panel, comprising the steps:

It is thus clear that the finishing material does not necessarily form the complete top layer of the decorative panel. It is also clear that the method of the third aspect is eminently suitable for manufacturing the panels with the characteristic features of the first and/or second aspect of the invention, as well as the preferred embodiments thereof.

A particular advantage of the present method is that both the decorative and the wear-resistant functions can be applied in a single layer, which greatly simplifies the production process, as well as the required raw material streams. Preferably, the top layer or decorative and/or wear-resistant layer extends through a substantial thickness, which leads to a considerable improvement in wear resistance, in comparison with techniques currently in use.

Preferably, application in step e) comprises the scattering of the granular and/or fibrous material. Scattering of the granular and/or fibrous material allows a homogeneous distribution thereof on and/or in the surface of the polymeric core, wherein a good-quality decor and a uniform wear resistance are obtained in a single step, i.e. application of a so-called scatter layer.

According to a further or another embodiment, the granular and/or fibrous material is selected from the group of stone, grit, gravel, quartz, aluminum oxide (AlO), polyvinyl chloride (PVC), synthetic fibers, textile fibers, natural fibers, or combinations thereof. Suitable synthetic fibers are nylon or PET fibers. The choice of the granular and/or fibrous material thus allows very varied decoration possibilities, without the need to apply an additional wear-resistant layer or to tailor such a layer specifically to this.

In some embodiments this scatter layer or layer of granular material has a thickness between 0.05 and 10.00 mm, preferably between 0.10 and 8.00 mm, more preferably between 0.50 and 5.00 mm. The scatter layer or layer of granular material is, in each of these embodiments, bonded to and/or in the polymer core, where it is to be understood that the scatter layer and the polymer core possibly run partially into each other. The scatter layer or layer of granular material with a thickness within the limits described herein allows the layer to form a relatively uniform decorative and/or wear-resistant layer, wherein the polymer core is only slightly or is not visible through this top layer or decorative and/or wear-resistant layer. In some embodiments the granular and/or fibrous material has a particle size and/or transverse dimension between 0.05 and 10.0 mm. According to some embodiments, particles with a larger particle size may also be used, wherein a coarser structured surface is obtained. Preferably the granular and/or fibrous material consists of particles with a particle size and/or transverse dimension between 0.10 and 8.00 mm, more preferably between 0.50 and 5.00 mm. Consequently, a relatively uniform spreading of the granular and/or fibrous material is possible, wherein a structured decorative and/or wear-resistant layer is formed, which differs markedly from for example a flat printed film.

According to some embodiments, the panel obtained comprises a coarse-structured surface, said surface being defined by the specific shape of the granular and/or fibrous material. In some embodiments the specific shape of the granular and/or fibrous material is flattened, for example by means of grinding techniques, possibly before scattering the granular and/or fibrous material, or else thereafter.

According to some embodiments, the individual particles of the granular and/or fibrous material have only limited hues, wherein a decor is obtained that is substantially uniform. According to some other embodiments, the individual particles of the granular and/or fibrous material have a number of different hues, wherein they display arbitrary ordering. In yet other embodiments, the individual particles of the granular and/or fibrous material display a number of different hues, and their ordering follows a pattern. It is thus clear that the decorative possibilities of the decorative and/or wear-resistant layer as described herein are very varied. Possibly, any voids between individual particles are filled with a polymer powder in order to obtain a more uniform surface.

According to a further or another embodiment, prior to step e) the polymer core is provided with a relief print. The forming of a relief print prior to application of the decorative and/or wear-resistant layer allows a panel to be obtained with a well-defined relief. Because the relief is applied prior to application of the top layer or decorative and/or wear-resistant layer, the wear-resistant properties of the panel obtained are not adversely affected thereby. Application of a relief further increases the decorative possibilities. Preferably, the final surface of the panel, for example the top layer formed by granular and/or fibrous material, also displays the relief that is applied in the surface of the polymer core. However, it is possible that this relief is available on the surface to a somewhat weakened extent, depending on the nature and dimensions of the granular and/or fibrous material.

With the same aim as in the third aspect, according to an independent fourth aspect the present invention relates to a method for manufacturing an extruded, preferably decorative, panel, comprising the steps:

Preferably, the layer comprising the second polymer mixture comprises one or more colorants. The colorants stated herein allow the second polymer mixture to be provided partially, if not completely, with one or more colors, which contribute to the decor of the top layer or decorative and/or wear-resistant layer. Since this layer is manufactured to a substantial thickness, particularly according to the relations as described herein, the decor also extends through said substantial thickness. When a decorative film only provides the surface with decor, the present method thus makes it possible to form a deeper decor that is also visible along any saw cuts, or places where the decorative and/or wear-resistant layer is damaged locally and/or on the surface.