Panel and Method of Producing a Panel

Abstract

The invention relates to a belt roller system for applying a surface structure in a floor panel or wall panel, said system comprising at least one upper endless belt and at least one lower endless belt, wherein each belt is rotatable around at least two pulleys, and at least one drive unit for rotating the upper endless belt and/or the lower endless belt. At least part of the upper endless belt comprises a surface structure and/or at least part of the lower endless belt comprises a surface structure. The upper endless belt and the lower endless belt are positioned substantially parallel to each other such that a panel can be transported between the upper endless belt and the lower endless belt such that the surface structure of the upper endless belt and/or the surface structure of the lower endless belt is transferred into the panel upon transport of the panel between said upper endless belt and said lower endless belt.

Claims

1. A belt roller system for applying a surface structure in a floor panel or wall panel, said system comprising: at least one upper endless belt and at least one lower endless belt, wherein each belt is rotatable around at least two pulleys, and at least one drive unit for rotating the upper endless belt and/or the lower endless belt, wherein at least part of the upper endless belt comprises a surface structure and/or wherein at least part of the lower endless belt comprises a surface structure, wherein the upper endless belt and the lower endless belt are positioned substantially parallel to each other such that a panel can be transported between the upper endless belt and the lower endless belt such that the surface structure of the upper endless belt and/or the surface structure of the lower endless belt is transferred into the panel upon transport of the panel between said upper endless belt and said lower endless belt.

2. The belt roller system according to claim 1, wherein one of the upper endless belt and the lower endless belt comprises a surface structure and wherein the other comprises a substantially smooth surface.

3. The belt roller system according to claim 1, wherein the surface structure of the upper endless belt and/or the lower endless belt comprises a plurality of protrusions and recessions, wherein a height difference between at least part of the protrusions and recessions is at least 1 mm.

4. The belt roller system according to claim 3, wherein an average diameter of at least part of the protrusions is at least 1 mm.

5. The belt roller system according to claim 1, wherein the surface structure of the upper endless belt and/or the surface structure of the lower endless belt comprises a repeated pattern.

6. The belt roller system according to claim 1, wherein the surface structure of the upper endless belt and/or the surface structure of the lower endless belt defines a cell pattern and/or a grid pattern.

7. The belt roller system according to claim 1, wherein at least one of the upper endless belt and the lower endless belt are made from a material chosen from steel, stainless steel, chilled cast iron, or combinations thereof.

8. The belt roller system according to claim 6, wherein at least part of the surface of at least one endless belt comprises a chrome surface, a plasma treated surface and/or a polytetrafluoroethylene surface, or a combination thereof.

9. The belt roller system according to claim 1, comprising at least one cooling unit configured for cooling at least part of a surface of a panel via the upper endless belt and/or the lower endless belt.

10. The belt roller system according to claim 1, wherein the length over which the upper endless belt and the lower endless belt are positioned substantially parallel to each other is at least 30 cm or at least 50 cm.

11. The belt roller system according to claim 1, wherein the length over which the upper endless belt and the lower endless belt are positioned substantially parallel to each other is in the range of 30 to 100 cm.

12. A method for applying a surface structure in a floor panel or a wall panel, wherein the panel is transported between at least one upper endless belt and at least one lower endless belt which are positioned substantially parallel, wherein at least part of the upper endless belt comprises a surface structure and/or wherein at least part of the lower endless belt comprises a surface structure, such that the surface structure of the upper endless belt and/or the surface structure of the lower endless belt is transferred into the panel upon transport of the panel between said upper endless belt and said lower endless belt.

13. The method according to claim 12, wherein one of the upper endless belt and the lower endless belt comprises a surface structure and wherein the other comprises a substantially smooth surface.

14. The method according to claim 12, wherein the surface structure of the upper endless belt and/or the lower endless belt comprises a plurality of protrusions and recessions, wherein a height difference between at least part of the protrusions and recessions is at least 1 mm.

15. The method according to claim 12, wherein the surface structure of the upper endless belt and/or the surface structure of the lower endless belt comprises a repeated pattern.

16. The method according to claim 12, wherein the surface structure of the upper endless belt and/or the surface structure of the lower endless belt defines a cell pattern and/or a grid pattern.

17. The method according to claim 12, wherein at least one of the upper endless belt and the lower endless belt are made from a material chosen from steel, stainless steel, chilled cast iron, or combinations thereof, optionally wherein at least part of the surface of at least one endless belt comprises a chrome surface, a plasma treated surface and/or a polytetrafluoroethylene surface, or combinations thereof.

18. The method according to claim 12, wherein at least part of a surface of the panel is cooled via the upper endless belt and/or the lower endless belt.

19. The method according to claim 12, wherein the length over which the panel is transported between the upper endless belt and the lower endless belt is at least 30 cm or at least 50 cm.

20. The method according to claim 12, wherein the length over which the panel is transported between the upper endless belt and the lower endless belt is in the range of 30 to 100 cm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The invention will now be elucidated into more detail with reference to the following non-limitative figures. Herein show:

[0035] FIG. 1 is a side view of a belt roller system according to the present invention;

[0036] FIG. 2a is a cutaway perspective view of an endless belt according to the present invention;

[0037] FIG. 2b is a cutaway perspective view of another endless belt according to the present invention;

[0038] FIG. 3 is a side view of another belt roller system according to the present invention;

[0039] FIG. 4a is a perspective view of a plate for the belt roller system of FIG. 3;

[0040] FIG. 4b is a perspective view of another plate for the belt roller system of FIG. 3;

[0041] FIG. 5a is a bottom view of a possible embodiment of a panel obtainable by the method according to the present invention;

[0042] FIGS. 5b-5c are bottom views of various possible embodiments of panels obtainable by the method according to the present invention; and

[0043] FIGS. 6a-6i are cross sectional views of various possible embodiments of cavities in panels obtainable by the method according to the present invention. Within these figures, similar references correspond to similar or equivalent components and/or technical features.

DETAILED DESCRIPTION

[0044] FIG. 1 shows a side view of a belt roller system 1 according to the present invention. The belt roller system 1 comprises an upper endless belt 2 and a lower endless belt 3. Both belts are rotatable around at least two pulleys 4. The at least two pulleys are driven by a drive unit 5. In operation, the drive unit 5 rotates the pulleys 4. A pliable extruded panel (not shown) is directed to an opening 6 between the upper endless belt 2 and the lower endless belt 3. By counter clockwise rotation of the upper endless belt 2 and clockwise rotation of the lower endless belt 3 around the pulleys 4, the panel is fed through the opening and advances through the belt roller system 1 between the endless belts 2,3.

[0045] FIG. 2a shows a cutaway section of the upper endless belt 2 of the belt roller system 1. The surface 7 of the upper endless belt 2 is smooth. FIG. 2b shows a cutaway section of the lower endless belt 3 of the belt roller system 1. The outer surface of lower endless belt 3 comprises a surface structure 8. The surface structure 8 has a hexagonal or honeycomb repeating pattern. The hexagonal shapes protrude from the surface of the lower endless belt 3, while the structure in between the hexagonal shapes is recessed in comparison to the hexagonal shapes.

[0046] Referring now to FIG. 1, an extruded panel, such as an SPC panel, enters the opening 6 and advances through the belt roller system 1. The structured surface 8 of the lower endless belt 3 imprints a negative of the honeycomb pattern in the bottom surface of the panel. At the same time, the smooth upper surface 7 of the upper endless belt 2 ensures that the upper surface of the panel remains smooth while a pattern is being imprinted in the bottom side of the panel.

[0047] As the panel progresses through the opening 6 between both belts 2,3, the structured surface 8 of the lower endless belt 3 remains in contact with the bottom side of the panel. As it takes some time for the panel to pass through the belt roller system 1, tension in the panel is allowed to dissipate while both belts 2,3 engage opposite surfaces of the panel. The panel enters the opening 6 between both rollers at an initial temperature. By the time the panel exits the belt roller system 1, the panel has cooled to a temperature below the initial temperature. As such, the panel has solidified somewhat. As a result of dissipating tension within the panel, and lowering of the temperature of the panel, the panel does not, or to a smaller extend tends to return to its shape prior to imprinting of the pattern, in comparison to a two roller system. A panel produced via a two roller system has cavities with a depth that is 80-90% of the height of the corresponding protrusion present on the roller. The belt roller system 1 enables to increase this dept to above 90% of the height of the corresponding protrusion present on the belt 3. Depths of 95% up to about 100% are attainable with the belt roller system 1.

[0048] To ensure that the structure provided on the panel is as close to a negative of the structure 8 provided on the lower endless belt 3, at least one cooling plate 9 are provided in one or both spaces delimited by the pulleys 4 and the belts 2,3, The at least one cooling plate 9 comprises at least one tube 10 wherein a cooling agent is allowed to circulate. Advantageously, the at least one cooling plate 9 cools down the panel while a structure is provided to the panel. Telegraphing of the structured surface of the panel is also prevented or at least reduced by the belt roller system 1. The at least one cooling plate 9 further decreases telegraphing.

[0049] FIG. 3 shows another embodiment of the belt roller system 1 according to the present invention. In this system 1, plates 10,11 are provided on the endless belts 2,3. The plates are connected to the endless belts 2,3 via interconnects 12. Advantageously, this allows individual plates to be replaced when worn. In this belt roller system 1, plates 11 having a surface structure are carried by the lower endless belt 3 via interconnects. The upper endless belt 2 carries plates 10 having a smooth surface structure. In operation the upper endless belt 2 rotates clockwise, while the lower endless belt 3 rotates counter clockwise. An extruded polymer melt (not shown) is caught between opposing plates, and the surface structure of the plate 11 is transferred on the melt evenly, shaping the melt into a panel having a bottom surface structure.

[0050] FIGS. 4a and 4b show a plate 10 with a smooth surface and a plate 11 with a structured surface 8. The plates 10,11 have edges 13 that prevent the pliable panel material from being pushed outward, towards the sides of the plate 10, 11, in a direction perpendicular to a direction of movement of the panel through the belt roller system 1. This ensures that the thickness of the panel remains uniform throughout the structure application process.

[0051] FIG. 5a shows a schematic representation of a possible embodiment of a panel 300 obtainable according to the method of the present invention. The figure shows a bottom view of a panel 300. The panel comprises a core layer 301, preferably comprising a composite material comprising a mixture of mineral material and thermoplastic material. The core layer 301 has a top surface (not shown) and a bottom surface which is shown in the picture. Part of the bottom surface of the core layer 301 is provided with a plurality of cavities 302. The cavities 302 extend towards the top surface of the core layer 301. The cavities 302 are integrally formed cavities 302. In the shown embodiment, the cavities 302 define a cell pattern, in particular a polygonal cell pattern. The figure show that the cavities 302 are separated via partitions 303, wherein at least part of the partitions 303 between the cavities 302 have a thickness which is smaller than the length and/or width of the cavities 302. In the shown embodiment, the cavities 302 are imprinted into the bottom surface of the core layer 301. Hence, the cavities 302 are imprinted cavities 302.

[0052] FIGS. 5b-5c show a bottom view of various further possible embodiments of a panel according to the present invention. The figures are in line with FIG. 3a, and show a bottom view of part of a panel according to the present invention. The figures show for each embodiment a plurality of impressed cavities 302, in particular in a repeated pattern. The cavities 302 are separated via partitions 303, wherein at least part of the partitions 303 between the cavities 302 have a thickness which is smaller than the length and/or width of the cavities 302.

[0053] FIGS. 6a-6i show cross sectional views of various possible embodiments of impressed cavities 402 of a panel obtainable by the method according to the present invention. It can be seen that the cavities 402 have rather clear boundaries, wherefore the cavities 402 could also function as attenuation chambers. The belt roller system 1 allows the cavities 402 to be form with a higher precision. This in turn enables acoustic designs to function optimally, as the cavities 402 are impressed in the panel as intended, and do not deform after impressing.

[0054] It will be apparent that the invention is not limited to the working examples shown and described herein, but that numerous variants are possible within the scope of the attached claims that will be obvious to a person skilled in the art.

[0055] The above-described inventive concepts are illustrated by several illustrative embodiments. It is conceivable that individual inventive concepts may be applied without, in so doing, also applying other details of the described example. It is not necessary to elaborate on examples of all conceivable combinations of the above-described inventive concepts, as a person skilled in the art will understand numerous inventive concepts can be (re)combined in order to arrive at a specific application.

[0056] The verb “comprise” and conjugations thereof used in this patent publication are understood to mean not only “comprise”, but are also understood to mean the phrases “contain”, “substantially consist of”, “formed by” and conjugations thereof. When it is referred to reinforcing layer also a reinforcing element can be meant, or vice versa. Within the scope of this invention, where the term ‘impressed cavity’ is used, also the term ‘cavity’ could be applied, or vice versa.