METHOD FOR MANUFACTURING A FLOOR BOARD

Abstract

A method of manufacturing a floor board comprises the steps of supplying a panel, printing a curable substance or surface removing substance onto the panel in a predefined pattern for creating an elevation on the panel at the pattern or removing a portion of the surface of the panel at the pattern, respectively, and curing the curable substance or removing any reaction products of the surface removing substance and the panel.

Claims

1. A method of manufacturing a floor board, comprising the steps of: supplying a panel, printing a substance onto the panel in a predefined pattern for creating an elevation on the panel at the pattern, wherein said substance is printed onto the panel by first printing a liquid onto the panel in said predefined pattern, and then providing a powder to the liquid, heating the powder so that the powder is melted together into a single mass which is elevated above the initial upper surface of the panel, hence forming the floor board.

2. A method according to claim 1, wherein the step of printing is digitally controlled.

3. The method according to claim 1, wherein the maximal thickness of the substance lies between 20 and 250 .Math.m.

4. The method according to claim 1, wherein the maximal thickness of the substance lies between 5 and 1000 .Math.m.

5. The method according to claim 1, wherein said powder stick to the liquid whereas abundant powder is removed.

6. The method according to claim 5, wherein the abundant powder is removed by suction.

7. The method according to claim 1, wherein the panel already comprises a basic decorative pattern.

8. The method according to claim 7, wherein the basic decorative pattern is directly printed on the panel.

9. The method according to claim 1, wherein the panel already comprises an embossment.

10. The method according to claim 1, wherein the panel comprises a flat surface.

11. The method according to claim 1, wherein the liquid is transparent or colored.

12. The method according to claim 1, wherein in said heating step the entire panel including the curable substance is placed in a heated environment.

13. The method according to claim 12, wherein after heating said panels are cooled before storing.

14. The method according to claim 1, wherein the liquid pattern only functions as a temporary carrier for carrying the powder in the desired pattern.

15. The method according to claim 14, wherein the liquid partly or fully disappears during the step of heating.

16. The method according to claim 15, wherein the liquid disappears by evaporation.

17. The method according to claim 1, wherein the powder comprises wear resistant particles.

18. The method according to claim 1, wherein the predefined pattern substantially corresponds to a decorative basic pattern being present on the panel.

19. The method according to claim 18, wherein camera recognizes the basic decorative pattern printed on the panel before arriving at a printing station for printing the liquid.

20. The method according to claim 1, wherein to form depressed portion in said pattern the substance is printed beside said intended depressed portions.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Aspects of the invention will be explained in more detail hereinafter with reference to drawings, which are very schematic representations of embodiments of the invention.

[0020] FIG. 1 is a schematic side view of an apparatus for performing an embodiment of the method.

[0021] FIG. 2 is a similar view as FIG. 1 of an alternative embodiment.

[0022] FIG. 3 is a similar view as FIG. 1 of another alternative embodiment.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT

[0023] FIG. 1 illustrates the main steps of an embodiment of the method. The manufacturing process performed by an apparatus 1 runs from the right to the left in FIG. 1. In this case a panel 2 is transported first to a digital printing station 3. At the digital printing station 3 a liquid is printed on an upper surface of the panel 2 in a predetermined pattern. The liquid may be an ink or varnish, being transparent or colored or any other liquid material.

[0024] Then, the printed panel 2 is transported to a powder unit 4, where an intermediate substance or a powder 5 is spread over the panel 2. The powder 5 will stick to the liquid. The liquid and the powder 5 form a substance which is curable. A part of the powder 5 may fall beside of the printed pattern or on a portion of the printed pattern which is already dry. That part of the powder 5 will be removed from the panel 2 by a suction device 6, but an alternative powder removing device is conceivable.

[0025] In a subsequent step the formed substance on the panel 2 is cured at a heating station 7. Before storing the resulting floor boards 2a at a storage station 9 the panels 2 may be cooled at a cooling station 8. In the heating station 7 the powder may be melted together into a single mass which is elevated above the initial upper surface of the panel 2. It is conceivable that the liquid and powder together form a curable substance or the powder itself forms a curable substance adhering to the panel 2 upon curing.

[0026] It is also conceivable that the powder forms the curable substance whereas the liquid pattern only functions as a temporary carrier for carrying the powder in the desired pattern. In this case the liquid may partly or fully disappear during the step of heating, for example by evaporation.

[0027] The powder 5 may be a swelling powder such that upon curing the volume of the substance becomes larger (and the elevations higher) than that of the sum of the liquid and the powder 5 separately. In practice, the maximal thickness of the substance after curing lies between 50 and 250 .mu.m, but a higher or lower thickness is conceivable. In practice, a thickness of 5-1000 .mu.m is preferred.

[0028] Furthermore, the powder 5 can also contain wear-resistant particles, for example corundum particles. It is advantageous that in the embodiment as illustrated in FIG. 1 the wear resistant particles are supplied separately from a printing head of the digital printing station, thus avoiding wear of the printing head through the presence of wear resistant particles.

[0029] Due to curing of the mixture of the liquid and the powder 5 or the powder 5 alone a solid elevated region arises on the panel 2 at the location where the liquid pattern was printed. The pattern may represent a real wood pattern or the like. The heating station 7 may comprise a UV-laser, for example, but alternative curing means are conceivable.

[0030] The apparatus of FIG. 1 may comprise a camera (not shown) for recognizing a basic pattern being printed on the panel 2 before arriving at the digital printing station 3. The pattern to be printed on the panel 2 at the digital printing station 3 may correspond to the basic pattern such that the panel 2 obtains an embossment in register.

[0031] Several types, shapes and dimensions of the powder 5 are conceivable. For example, metallic resin powder which creates a metallic effect after melting, lustrous resin powder in which lustrous particle are added to the powder, anti-static powder which avoids build-up of electrostatic charge, and powders which generate pearlescent effect, matt effect, or odour effect.

[0032] In an alternative embodiment the curable substance is directly printed at the printing station 10 in a predetermined pattern on a panel 2. This is illustrated in FIG. 2. In this case, a relatively large amount of substance has to be printed by the printing station 10. Other features as described in relation to the embodiment as illustrated in FIG. 1 are also applicable to the embodiment as illustrated in FIG. 2.

[0033] In a further alternative embodiment of the method a layer of the substance is spread onto the panel 2 at a substance spread device 11 and then the predetermined relief pattern is created by a digitally controlled impacting member 12, see FIG. 3. In this case the substance may be spread uniformly over the panel 2. The digitally controlled impacting member 12 is repeatably pressed into the curable substance and movable in a plane extending parallel to the panel 2 so as to form the relief pattern. Other features as described in relation to the embodiment as illustrated in FIG. 1 are also applicable to the embodiment as illustrated in FIG. 3.

[0034] Instead of locally displacing the substance by an impacting member 12 it is also conceivable to remove the substance locally from the panel, for example by a suction device.

[0035] In another alternative method a surface removing substance can be applied on the panel (directly or indirectly via powder in a printed liquid as described hereinbefore) such that the local surface of the panel 2 at the intended pattern is removed. The substance can be applied on the panel in a manner as illustrated in FIGS. 1 and 2. The substance is selected such that it reacts with the surface of the panel 2 so as to remove a portion thereof. Contrary to the embodiments as described above the relief pattern of the panel 2 is formed by removing material from the panel 2 instead of adding material. After heating and/or cooling of the substrate on the panel any reaction products may be removed by pressed air, for example. It is also possible that neither heating nor cooling is necessary in this embodiment. After applying the embossment in this way the panel may be covered with a finishing layer containing wear resistant particles.

[0036] Alternatively, the surface removing substance is selected such that it reacts with the surface of the panel 2 after being activated. For example, the substance can be activated by a heat source, UV radiation, a laser beam or the like. When the surface removing substance is printed in a predefined pattern onto the panel 2, an activation device needs not to be focussed very accurately on specific areas of the panel surface since only those areas will be activated where the substance is present. After activation and reaction of the substance with the panel surface, any reaction products may be removed.

[0037] Panels having the same decorative basic pattern may be provided with different relief patterns, for example one of the type embossing-in-register and the other one of the type brushed all-over. This enlarges the variation of appearances of floor boards.

[0038] The panel 2 on which the curable substance or surface removing surface is applied, may be made of HDF, WPC, polymer composite or engineered polymer, LVT, PVC or the like. It is noted that the method can also be applied on a flexible sheet which will be laminated to a substrate at a later stage so as to form a floor board.

[0039] The invention is not limited to the embodiments shown in the figures, which can be varied in several ways within the scope of the invention. It is for example possible that the method is applied on alternative substrates than on a panel or a sheet, for example on the packaging material of floor panels. Furthermore, the digital printing station may be replaced by alternative printing means, for example a conventional printing roller as known from the prior art roller printing process.