NL2013100B1

NL2013100B1 - Panel suitable for installation of a waterproof floor or wall covering, method of producing a panel.

Info

Publication number: NL2013100B1
Application number: NL2013100A
Authority: NL
Inventors: Luc Martine Baert Thomas; Drevet Anthony; Van Poyer Tom
Original assignee: Champion Link Int Corp
Priority date: 2014-06-30
Filing date: 2014-06-30
Publication date: 2016-07-11

Abstract

Panel of a substantially flat, rectangular shape suitable for installation of a waterproof floor or wall covering by interconnecting a plurality of said panels with each other, wherein the panel has a top surface, a bottom surface, and at least four substantially linear side edges comprising at least one pair of opposite side edges which are provided with interconnecting coupling means for interconnecting one panel within another, the panel having a layered structure which comprises a main layer basically composed of thermoplastic material and a top layer basically composed of a cement material on the top side of said main layer.

Description

Panel suitable for installation of a waterproof floor or wall covering, method of producing a panel

The invention relates in a first aspect, to a panel of a substantially flat, rectangular shape suitable for installation of a waterproof floor or wall covering by interconnecting a plurality of said panels with each other, wherein the panel having a top surface, a bottom surface, and at least four substantially linear side edges comprising at least one pair of opposite side edges which are provided with interconnecting coupling means for interconnecting one panel within another.

The invention relates in a second aspect to a method of producing a panel according to the first aspect of the invention.

In the field of floor and wall coverings, panels are widely used based on wood materials or derivatives thereof, especially as a material for the main or central layer of the panel. An example is given in US patent 6,688,061. A major disadvantage is the hygroscopic nature of such materials, which affects the lifetime and durability of such panels especially in rooms that are regularly exposed to water spills such as a bathroom and a kitchen.

To render a panel waterproof, thermoplastic materials are used such as polyvinyl chloride for its waterproof properties. Polyvinyl chloride that is used for panels such as in patent CN 100419019, has a flexible quality which requires a perfectly smooth and even surface of the substrate on which the panel covering is applied. If such is not the case, any unevenness will be visible through the panel as it conforms with the underlying substrate surface, which is a detrimental effect from an aesthetic point of view to the user. Furthermore, the upper surface of the panel is less durable because the scratch resistance of the polyvinyl chloride is relatively low. Finally, the flexibility of the panel is cumbersome in regard of installing a covering of interconnected panels, because the assembling of the mutual interconnecting coupling means is more difficult when these can bend away from each other.

An alternative waterproof panel that is more rigid than the above flexible thermoplastic material, is a prefabricated tile from cement or concrete. The thickness required for its application is at least 16 mm, which makes the tile considerably more expensive in comparison to the thermoplastic material. Still, an evening of the underlying substrate surface is required, as well as manually gluing the tile to the substrate. A direction into which such cement- or concrete-based panels have further developed is a layered structure of a magnesium oxide main layer on which a cement top layer is fixed. An example is given in Chinese utility model CN 202644903 U. Such a panel can however only be provided with basic interconnecting coupling means such as a teeth and groove assembly (‘1st generation’ coupling), because the brittle nature of the magnesium oxide layer does not allow the milling of an intricate profiling, such as known from a groove and tongue assembly having interlocking features (‘2nd /3rd / 4th generation’). As such, glue is needed to prevent neighbouring panels from drifting away from each other. Furthermore, the magnesium oxide layer has a relatively high density of 1100 kg/m3, which is a disadvantage. Unsatisfactory in regard of the use as a floor covering is that when the panel is tread upon, the sound of footsteps is relatively loud because of the material use. In addition, the panel is rigid, which requires an evening of the underlying substrate surface.

It is an objective of the invention to meet a general need for an attractive waterproof panel, that eliminates completely or in part, one or more of the disadvantages related to the waterproof panels known from the prior art.

The above objective of the invention, is met by the provision of a panel according to the above preamble, wherein the panel has a layered structure which comprises a main layer basically composed of thermoplastic material and a top layer basically composed of a cement material on the top side of said main layer.

It is thus possible to mill intricate interconnecting coupling means as profiled structures on the side edges of the main layer, while the look and feel of a true cement tile is included on the top surface of the panel. Such intricate coupling means allow for a floating installation of a floor covering, i.e. wherein no glue is needed to prevent the drifting apart of neighbouring panels. Moreover, the panel has a considerably reduced weight, as its main layer has a low density. The low density also entails a lesser burden on the milling tools which positively affects the life time of the milling tools.

Further, the thermoplastic material provides thermal insulation and has sound dampening qualities.

Both layers are waterproof by nature, because both the thermoplastic material and cement are waterproof. Preferably in the panel according to the invention, the cement material is hydraulic cement, and contains more preferably at least 50 wt.% calcium oxide, and most preferably 60 wt.% calcium oxide. The calcium oxide in cement is typically a complex of one calcium oxide molecule with one silicate S1O2 molecule and one or more hydrates H2O molecules.

During the final stage of hardening of cement the following reactions occur: (3Ca0 Si02)2 + (x+3) H20 3 Ca02Si02xH20 + 3 Ca(OH)2 (2Ca0 Si02)2 + (x+1) H20 -> 3 Ca02-Si02-xH20 + Ca(OH)2

Typically, the cement material in the top layer according to the invention contains at least 5 wt.% silica.

Preferably, the panel according to the invention comprises two pairs of opposite side edges which are provided with interconnecting coupling means. As such, a floating floor can be installed without the need of glue at all sides of each panel.

It is further preferred in the panel according to the invention, that the interconnecting coupling means comprise a tongue and a groove wherein the tongue is provided on one side edge of one pair of opposite side edges, and the groove is provided on the other side edge of the same pair of opposite side edges. Such a design of coupling means is well-known in the art and has proven highly suitable for panels for floating floors.

In the panel according to the invention it is preferred that the interconnecting coupling means have an interlocking feature which avoids free movement of interconnected panels. Such an interlocking feature may be a projection and a respective recess provided on the respective opposite side edges by which neighbouring panels interlock with each other.

It is preferred in the panel according to the invention that the thermoplastic material comprises polyvinyl chloride or a derivative thereof. Such a material is highly suitable for its use as main component for the main layer. Another thermoplastic material that can be used for the main layer is polyethylene.

In particular, it is preferred in the panel according to the invention that the thermoplastic material has a foam structure which preferably includes an open-cell structure. The foam structure consists basically of a thermoplastic matrix in which closed and/or open cells are present. The foam structure is typically obtained by adding blowing agents to the thermoplastic melt, before it is formed and hardened into its final shape. As the foam structure has a lower density than a solid structure, the weight of the central layer is further reduced which is advantageous for the panel. The foam structure has furthermore the inherent property of better sound dampening properties than a solid structure, which provides a further attractive property to the panel. Analogously, the foam structure further improves the thermal isolation quality of the thermoplastic layer over a solid structure. The open-cell structure is preferably included as it contributes in a dominant way to the reduced density of the foam structure, and accordingly to the consequent advantageous effects above. Dependent on the chosen parameters, a density of the main layer of 300 to 900 kg/m3 can thus be achieved, of which a density in the range of 650 to 800 kg/m3 is most suitable for the panel.

In respect of the central layer of polyvinyl chloride with a foam structure the following properties are preferred: pore size: 0.01 to 0.15 mm pore volume: 20-50% density: 650 to 800 kg/m3 inherent viscosity: 0.6 to 0.84

It is preferred in the panel according to the invention, that the main layer basically composed of a thermoplastic material contains one or more filler materials chosen from the group comprising calcium carbonate, wood dust, bamboo dust, rubber, cork, jute, straw, seagrass, and paper, wherein preferably the total ratio of filler material in the main layer is 15 wt.% or lower. The filler material imparts rigidity to the main layer, and a better aesthetic appearance. In addition, the main layer may contain a pigment for imparting an attractive color to the thermoplastic material.

Preferably, in the panel according to the invention, the top layer basically composed of a cement material comprises one or more additives in particulate form, the additives being chosen from the group comprising wood, bamboo, fiberglass, straw, jute, seagrass, cellulose, granite, quartz, marble, soapstone, plastic, and mica. The additives render a decorative and/or enforcing quality to the top surface. The amount of additives is preferably at least 10 wt.% , and more preferably at least 30 wt.%. Accordingly, the top layer has a density that varies from 1000 to 1800 kg/m3, the preferred density is 1200 kg/m3.

In a particular embodiment of the panel according to the invention, the top layer is adhered to the main layer by an adhesive material. With further preference, the adhesive material is of a waterproof quality.

In a preferred embodiment of the panel according to the invention, the top layer has a thickness of 1.0 - 16 mm, and the main layer has a thickness of 2.0 - 20 mm. Accordingly, the panel has a preferred overall thickness of 3.0 - 36 mm. In a typical example of the panel the top layer and the main layer each have a thickness of 4.0 mm.

With further preference, in the panel according to the invention, a buffer layer is provided on the bottom side of the top layer. The buffer layer imparts some shock absorbing qualities to the panel in case of a heavy impact on the top surface of the panel. Furthermore, the buffer layer attributes a sound dampening effect to the panel. For that purpose, the buffer layer comprises advantageously one or more materials chosen from the group comprising cork, rubber, leather, jute, cellulosic paper, fiberglass, a plastic polymer sheet.

In a special embodiment of the panel according to the invention, a backing layer is provided on the bottom side of the main layer. Preferably the backing layer comprises one or more materials chosen from the group comprising cork, rubber, a solid foam material, cross-linked polyethylene, and cross-linked ethylene vinyl acetate. The backing layer may compensate further for any unevenness on the substrate surface on which the panels are applied. Furthermore, the backing layer attributes a sound dampening effect to the panel.

It is further preferred in the panel according to the invention, that the interconnecting coupling means are part of the main layer and/or the top layer. Dependent on the thickness of the top layer, the interconnecting coupling means are to be provided in either the top or the main layer, or in both layers, all of which variants are envisaged according to the invention.

In the panel according to the invention, it is preferred that the top layer forms a part of at least one pair of the opposite side edges, preferably of two pairs of the opposite side edges. As such, the top layer surface extends to the respective opposite side edges of which it forms a part, so that the top layers of direct neighbouring panels appear as a continuous layer.

In a particular embodiment of the panel according to the invention, the upper part of at least one side edge of at least one pair of opposite side edges is provided with a bevel. The main purpose of the bevel is to even out any possible height difference between two panels installed next to each other. When two panels installed next to each other have a slight difference in thickness, the thicker panel will have one edge projecting from the floor surface, which is a safety risk for a person walking over the floor. The projecting edge is also more prone to damage, thus reducing the durability of the floor covering. The bevel avoids that any sharp or right cornered edges stick out from the floor surface.

Furthermore, in the panel according to invention, the top layer is preferably provided with a decorative surface. Such can be achieved either by applying an additional decorative layer on the top surface of the top layer, or by colouring of or printing on the top surface.

It is also preferred that the panel according to the invention, has a top layer which has a textured top surface. The textured surface can be chosen such, that it mimics the feel of a natural stone tile, a ceramic tile, etc.

In the panel according to any of the preceding claims, the top layer is preferably coated with a protective material. As such additional protection from scratching or etching during use is provided to the panel. The protective material that is used may include oil or varnish. A special aspect of the invention relates to a waterproof floor or wall covering composed of a plurality of interconnected panels, wherein the panels are conform the first aspect of the invention. Such a covering profits from the same advantages as set out already above.

In a second aspect, the invention relates to a method of producing a panel according to the first step of the invention, comprising the steps of: a) providing a main layer of a substantially flat, rectangular shape which is basically composed of a thermoplastic material, b) providing a top layer of a substantially flat, rectangular shape which is basically composed of a cement material, c) assembling the top layer obtained in the above step on the top side of the main layer obtained in the above step, wherein an adhesive is applied at the interface between both layers, d) applying pressure on the assembly of the top layer and main layer to obtain a layered structure having a top surface, a bottom surface, and two pairs of opposite side edges; e) milling a profile structure on one pair of opposite side edges and preferably on two pairs of opposite side edges, wherein the profile structures are interconnecting coupling means.

The method according to the invention provides a new and expedient way to provide a panel according to the first aspect of the invention.

Step a) can for instance be performed by extruding a melt of said thermoplastic material into a sheet material and subsequent cooling to harden the sheet material. Subsequently the sheet material is cut to a suitable size to obtain a main layer. Other techniques for forming of a main layer out of thermoplastic material are also envisaged.

Step b) can for instance be formed by filling a suitable mold with a fluid precursor of the cement material, and subsequent application of pressure and heat to obtain a hardened top layer.

Step d) can be performed in a cold press. Optionally, heat is applied during pressing.

An alternative method of producing a panel according to the first aspect of the invention comprises the steps of: a) providing a main layer of a substantially flat, rectangular shape which is basically composed of a thermoplastic material, b) applying on the top side of the main layer obtained by the above step, a fluid layer of a precursor of cement material and allowing the precursor to harden so as to obtain a top layer basically composed of a hardened cement material, c) milling a profile structure on one pair of opposite side edges and preferably on two pairs of opposite side edges, wherein the profile structures are interconnecting coupling means.

In this method, no additional adhesive is used, because the fluid precursor of cement material has adhesive properties. The method thus provides a cost saving in producing a panel. Furthermore, it allows to create a very thin top layer of cement (of about 1 mm. thickness) on the main layer, which is not obtainable when the top layer and main layer are produced separately according to the first method described above.

In order to have a sufficient bonding strength between the cement and the main layer in the above alternative method, it is preferred that the main layer has a rough surface or a surface with texture. The rough surface can be created using a sanding machine or steel wire brush roller. The texture can be made using any suitable embossing method during or after the fabrication of the thermoplastic main layer.

In step b) it is practical that the fluid layer is applied on the top side of the main layer within a temporary boundary wall that delimits the surface over which the fluid layer is spread out.

According to a further special aspect, the invention relates to a panel according to the first aspect of the invention, that is produced using the method steps according to the second aspect of the invention.

Example

An example of producing a panel according to the invention is as follows: 1. PVC core a. Raw material: PVC powder, Blowing agent, Plasticizer, Stabilizer, Ink, Lubricant, Bonding agent, Filler (usually calcium carbonate powder and/or wood dust) b. The raw material are weighed and then mechanically mixed under heat (generally 100-120°C). c. Then the PVC compound is fed into a two twin-screw extruders which is heated to a temperature between 160 and 250°C. The twin screw are designed to enable plasticizing and homogenizing of the PVC compound. d. Due to the high temperature, blowing agent evaporates and gas bubbles are being trapped in the PVC compound which create the final foam structure to the PVC sheet. Blowing agent are chosen to evaporate at 180°C degrees. e. The PVC compound is extruded by the twin-screw through a mold which gives it the shape of a sheet. f. The sheet immediately goes through a series of cooling plate which harden the PVC compound. An oil cooling system is preferred because it promotes the foaming homogeneity. The oil temperature is controlled between 80 to 130°C. g. The PVC foam sheet is then cut to the size needed. 2. Cement board a. The raw cement material is weighed and mechanically mixed to obtain a cement precursor. b. The cement precursor is placed in a mold and pressed to remove water and adjust the cement compound to the thickness desired to obtain a cement plate. c. The cement plate is dried in an oven. d. The cement plate surface is polished. 3. As sembly proces s a. The PVC sheet and Cement board are cut at size needed. b. Then a waterproof adhesive is applied on the PVC sheet by passing the sheet through a gluing roller. c. The cement board is immediately placed on top of the adhesive d. The assembly board is then cold pressed (under a pressure of 3 to 8 MPa) for several hours to allow curing of the adhesive. 4. Milling process a. the assembled panel is first led through a series of milling tools that mill a first pair of opposite side edges at the same time. b. the assembled panel is subsequently led through a series of milling tools that mill a second pair of opposite side edges at the same time.

The invention will be further explained with reference to the appended figures wherein:

Fig 1 shows in perspective a preferred embodiment of the panel according to the invention;

Fig. 2 shows a cross section of three preferred embodiments of the panel according to the invention;

Fig. 3 show in detail a cross-section of the layered structure of another preferred embodiment of the panel according to the invention.

Figure 1 shows a panel 1 suitable for assembling a waterproof floor or wall covering by interconnecting a plurality of said panels with each other, wherein the panel has a substantially planar top surface 3, and a substantially planar bottom surface 5, at least four substantially linear side edges 7a,7b,7c,7d comprising at least one pair of opposite side edges 7a,7c which are provided with profile structures as interconnecting coupling means for interconnecting one panel within another, the panel having a layered structure which comprises a foam structured polyvinyl chloride layer as a main layer 2, a top layer 4 basically composed of cement material, and a protective layer 6.

Figure 2 includes three cross sectional views Fig. 2a, 2b and 2c taken across the width of three preferred embodiments of the panel according to the invention. Each embodiment includes a pair of opposite side edges 7b,7d each provided with a profile structure in the form of a tongue 20 and a groove 22 respectively, each having an interlocking feature 24 (a recess), respectively 26 (a projection) which avoids free movement of interconnected panels when the tongue of one panel is inserted in the groove of another neighbouring panel.

The depicted variants shown in fig. 2a, 2b and 2c have different thicknesses of the cement top layer 4 and the thermoplastic main layer 2, such that the interconnecting coupling means 20, 22 are provided in the main layer 2 only (fig. 2a), in the top layer 4 only (fig. 2c), or in both the main layer and the top layer (fig. 2b).

Figure 3 shows in detail a cross-section of the layered structure of panel, which is composed of a protective layer 6, a cement top layer 4, a buffer layer 30, a foam structured polyvinyl chloride layer 2 and a backing layer 32.

Claims

A panel with a substantially flat rectangular shape, suitable for installation of a waterproof floor or wall covering by interconnecting a number of panels with each other, the panel having an upper surface, a lower surface, and at least four substantially linear side edges, comprising at least one pair of overlying side edges, which are provided with mutually connecting coupling means for mutually connecting one panel with another, the panel having a layered structure comprising a main layer consisting of thermoplastic material and a fundamentally consisting of a cement material existing top layer on the top side of the main layer.

Panel according to claim 1, wherein the cement material is hydraulic cement, and preferably comprises at least 50% by weight of calcium oxide and / or 5% by weight of silicon dioxide.

3. Panel as claimed in any of the foregoing claims, comprising two pairs of opposite side edges which are provided with mutually connecting coupling means.

4. Panel as claimed in any of the foregoing claims, wherein the mutually connecting coupling means comprise a tongue and a groove, wherein the tongue is provided on one side edge with one pair of opposite side edges, and the groove on the other side edge is provided with the same pair of opposite side edges. .

5. Panel as claimed in any of the foregoing claims, wherein the mutually connecting coupling means have an mutually locking feature that avoids free movement of the mutually connected panels.

The panel of any one of the preceding claims, wherein the thermoplastic material comprises polyvinyl chloride or a derivative thereof.

The panel according to any of the preceding claims, wherein the thermoplastic material has a foam structure that preferably comprises an open cell structure.

Panel according to any of the preceding claims, wherein the main layer consisting of a thermoplastic material comprises one or more filling materials selected from the group comprising calcium carbonate, wood dust, bamboo dust, rubber, cork, jute, straw, seagrass, and paper, wherein the total ratio of filler material in the main layer is preferably 15% by weight or lower.

Panel according to one of the preceding claims, wherein the top layer consisting of a cement material basically comprises one or more additives in particle form, the additives being selected from the group comprising wood, bamboo, fiber glass, straw, jute, seagrass, cellulose, granite , quartz, marble, soapstone, plastic, and mica.

The panel according to any of the preceding claims, wherein the top layer is adhered to the main layer by means of an adhesive material.

The panel according to any of the preceding claims, wherein the thickness of the top layer is 1.0 - 16 mm, and the thickness of the main layer is 2.0 - 20 mm.

12. Panel according to one of the preceding claims, wherein a buffer layer is provided on the underside of the top layer.

Panel according to one of the preceding claims, wherein a base layer is provided on the underside of the main layer.

14. Panel as claimed in any of the foregoing claims, wherein the mutually connecting coupling means form part of the main layer and / or the top layer.

Panel according to any of the preceding claims, wherein the top layer forms a part of at least one pair of opposite side edges, preferably of two pairs of opposite side edges.

A panel according to any one of the preceding claims, wherein the upper part of at least one side edge of at least one pair of opposite side edges is provided with a bevel.

A panel according to any one of the preceding claims, wherein the top layer is provided with a decorative surface.

The panel according to any of the preceding claims, wherein the top layer has a textured top surface.

The panel according to any of the preceding claims, wherein the top layer is covered with a protective material.

A method of producing a panel of a substantially flat rectangular shape suitable for installing a floor covering, comprising the steps of: a) providing a main layer of a substantially flat rectangular shape that is basically composed of a thermoplastic material, b) providing a top layer of a substantially flat rectangular shape that is basically composed of a cement material, c) assembling the top layer obtained in the above step on the top side of the main layer obtained in the above step, wherein an adhesive is applied to the interface between the two layers, d) applying pressure to the top layer and main layer assembly to obtain a layered structure with an upper surface, a lower surface, and two pairs of opposite side edges; e) milling a profile structure on one pair of opposite side edges and preferably on two pairs of opposite side edges, the profile structures being interconnecting coupling means.

A method of producing a panel of a substantially flat rectangular shape suitable for installing a floor covering, comprising the steps of: - providing a main layer of a substantially flat rectangular shape that is basically composed of a thermoplastic - applying a top layer of a fluid layer of a precursor of cement material obtained by the above step and allowing the precursor to cure to obtain a top layer consisting essentially of a hardened cement material, - milling a profile structure on one pair of opposite side edges and preferably on two pairs of opposite side edges, wherein the profile structures are mutually connecting coupling means.

The panel of any one of the preceding claims 1 to 19, which is produced by the process steps of claims 20 or 21.