METHOD OF MANUFACTURING A PANEL

Abstract

A method is provided for manufacturing a panel. of the method may involve supplying a substrate having an upper side. A layer may be provided onto the upper side. The upper side may be irradiated so as to cure at least a part of the layer by irradiation, hence forming the panel. The layer may include a liquid coating on substantially the entire upper side and a substance which is digitally printed locally on the upper side. The substance and the liquid coating may cooperate such that either (1) the coating and the substance react with each other, whereas the substance is a liquid that is printed on the upper side before the coating is applied and wherein the substance and the coating have different surface tensions, or (2) the coating is non-curable or only curable to a limited extent by the irradiation, whereas the substance makes the coating curable by the irradiation at locations where they meet each other.

Claims

1. A method of manufacturing a panel, the method comprising: supplying a substrate having an upper side; applying a layer onto the upper side; and irradiating the upper side so as to cure at least a part of the layer by irradiation, hence forming the panel; wherein the layer includes a liquid coating on the entire upper side and a substance which is digitally printed locally on the upper side; wherein the substance and the liquid coating cooperate such that either the liquid coating and the substance react with each other, wherein the substance is a liquid that is printed on the upper side before the liquid coating is applied, and wherein the substance and the liquid coating have different surface tensions, or the liquid coating is non-curable or only curable to a limited extent by the irradiation, wherein the substance makes the liquid coating curable by the irradiation at locations where the substance and the liquid coating meet each other.

2. The method according to claim 1, wherein the liquid coating and the substance react with each other; and wherein the substance is a liquid that is printed on the upper side before the liquid coating is applied; and wherein the substance and the liquid coating have different surface tensions.

3. The method according to claim 2, wherein the liquid coating and the substance start to react with each other before the irradiating.

4. The method according to claim 2, wherein the substance has a higher surface tension than the liquid coating.

5. The method according to claim 2, wherein the substance is a varnish.

6. The method according to claim 2, wherein the liquid coating is a glossy coating.

7. The method according to claim 1, wherein the liquid coating is non-curable or only curable to a limited extent by the irradiation; and wherein the substance makes the liquid coating curable by the irradiation at locations where the substance and the liquid coating meet each other.

8. The method according to claim 7, wherein the substance comprises a photo-initiator.

9. The method according to claim 7, wherein the substance is a first substance; wherein a second substance is digitally printed locally on the upper side adjacent to the first substance; and wherein the second substance inhibits curing of the liquid coating at locations where the second substance and the liquid coating meet each other such that the coating remains liquid there.

10. The method according to claim 9, wherein the second substance comprises a UV absorber so as to inhibit propagation of radicals.

11. The method according to claim 9, wherein the first and the second substances are printed synchronously.

12. The method according to claim 7, wherein remaining liquid is removed from the upper side after irradiating the upper side.

13. The method according to claim 7, wherein the substance is printed after applying the liquid coating on the upper side.

14. The method according to claim 1, wherein the substrate is made of a wood-based material or a plastic-based material or a mineral-based material.

15. The method according to claim 1, wherein the irradiating comprises UV irradiating.

16. The method according to claim 1, further comprising applying a decor on the upper side before applying the layer.

17. The method according to claim 16, wherein the decor is printed directly onto the upper side.

18. The method according to claim 16, wherein a primer, or an alternative basecoat, is applied onto the upper side before applying the decor.

19. The method according to claim 16, wherein the decor is applied by means of a decorative layer which is attached to the substrate.

20. The method according to claim 1, wherein the liquid coating is transparent.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The invention will hereafter be elucidated with reference to very schematic drawings showing embodiments of the invention by way of example.

[0039] FIG. 1 is an illustrative view, showing steps of an embodiment of a method of manufacturing a panel according to invention.

[0040] FIG. 2 is a similar view as FIG. 1, illustrating an alternative embodiment.

DESCRIPTION OF NON-LIMITING EMBODIMENTS

[0041] FIG. 1 illustrates successive steps of an embodiment of a method of manufacturing a panel 1 according to invention. The left side of FIG. 1 shows a substrate 2 which has an upper side 3 and a lower side 4. The substrate 2 may be made of a wood-based material, a plastic-based material or mineral-based material. A primer 5 is applied on the upper side 3 by means of a roller 6. After curing the primer 5 by a curing device 7 a decor 8 is printed on the cured primer 5 by means of a digital decor printer 9. When the printed decor 8 has dried a digital varnish printer 10 prints a liquid substance in the form of a UV-curable varnish 11 at discrete areas on the upper side 3 of the substrate 2, possibly in register with the decor 8. Subsequently, a UV-curable liquid glossy coating 12 is provided on the entire upper side 3 by means of a coating device 13 such that the varnish 11, the decor 8 and the primer 5 are fully covered by the coating 12.

[0042] The varnish 11 and the coating 12 have different surface tensions such that they repel each other. Consequently, the varnish 11 does not fully spread across the upper side 3. Furthermore, the varnish 11 and the coating 12 cooperate such that they react with each other, resulting in a finely textured upper surface of the coating 12 at the areas where the varnish 11 has been printed. In a next step the upper side 3 is irradiated by means of a UV radiator 14 so as to cure the coating 12 and the varnish 11, hence forming the panel 1. The rightmost picture of FIG. 1 shows the resulting panel 1, of which the upper side 3 has glossy regions 15 and matt regions 16.

[0043] In this embodiment the coating 12 and the varnish 11 already start to react with each other before the step of irradiating. It is also possible that the reaction only occurs during the step of irradiating or that the reaction has ended before the step of irradiating. The coating 12 and the varnish 11 together form a layer which is applied on the upper side 3 of the substrate 2 before irradiating the upper side 3 so as to cure the layer. The UV radiator 14 may be provided with Hg lamps and/or LED lamps for creating photo-polymerization in the coating 12 and the varnish 11.

[0044] FIG. 2 illustrates successive steps of an alternative embodiment of a method of manufacturing a panel 1 according to the invention. The first steps are comparable to the embodiment as described hereinbefore, but when the printed decor 8 has dried a liquid coating 17 which is not curable by means of the UV radiator 14 is applied on the upper side 3 by means of a non-curable coating device 18. Subsequently, a photo initiator 19 is printed to the liquid coating 17 in register with the decor 8 by means of a photo initiator printer 20. Although FIG. 2 shows that the photo initiator 19 lies on top of the coating 17 it may also penetrate into the coating 17. The photo initiator 19 makes the coating 17 curable where they meet each other. At the same time or in a next step a UV absorber 21 is printed to the coating 17 by means of a UV absorber printer 22, in register with the decor 8. In this case the term ‘in register’ means that the UV absorber 21 is printed adjacent to regions where the photo initiator 19 is printed, hence adjacent regions where the decor 8 is located. It is noted that in some embodiments the UV absorber 21 and the photo initiator 19 can be printed with the same printer.

[0045] FIG. 2 shows that the UV absorber 21 is only printed within small areas adjacent to the regions where the photo initiator 19 is printed, but it is also possible to fill the entire areas where the photo initiator 19 is absent. The UV absorber 21 inhibits curing of the coating 17 at locations where they meet each other such that the coating 17 remains liquid there. By printing the UV absorber 21 adjacent to the photo initiator 19 the areas of the coating 17 that are intended to be cured can be bordered accurately since uncontrolled propagation of the curing reaction can be limited; for example, the UV absorber 21 inhibits propagation of radicals formed by the photo initiator 19. It is possible to vary the curing conditions by changing the quantity of the printed photo initiator 19, for example.

[0046] In a next step the upper side 3 is irradiated by means of the UV radiator 14 after which remaining non-curable coating 17 is removed by a mechanical device, such as a brushing machine 23. The resulting panel 1 has elevated surface areas at the printed decor 8.

[0047] The removal of non-curable or non-cured coating can also be carried out by an air jet with high pressure or by a water jet with high pressure or by using a suitable solvent, for example.

[0048] The invention is not limited to the embodiments shown in the drawings and described hereinbefore, which may be varied in different manners within the scope of the claims and their technical equivalents.

[0049] The invention is further disclosed by the following list of numbered items.

[0050] 1. A method of manufacturing a panel (1), comprising the steps of supplying a substrate (2) having an upper side (3), applying a layer onto the upper side (3) and subsequently irradiating the upper side (3) so as to cure at least a part of the layer by irradiation, hence forming the panel (1), wherein the layer comprises a liquid coating (12, 17) on substantially the entire upper side (3) and a substance (11, 19, 21) which is digitally printed locally on the upper side (3), wherein the substance (11, 19, 21) and the liquid coating (12, 17, 21) cooperate such that either [0051] the coating (12) and the substance (11) react with each other, whereas the substance (11) is a liquid that is printed on the upper side (3) before the coating (12) is applied and wherein the substance (11) and the coating (12) have different surface tensions, or [0052] the coating (17) is non-curable or only curable to a limited extent by the irradiation, whereas the substance (19) makes the coating (17) curable by the irradiation at locations where they meet each other.

[0053] 2. A method according to item 1, wherein the coating (12) and the substance react with each other, whereas the substance (11) is a liquid that is printed on the upper side (3) before the coating (12) is applied and the substance (11) and the coating (12) have different surface tensions.

[0054] 3. A method according to item 2, wherein the coating (12) and the substance (11) already start to react with each other before the step of irradiating.

[0055] 4. A method according to item 2 or 3, wherein the substance (11) has a higher surface tension than the coating (12).

[0056] 5. A method according to any one of the items 2-4, wherein the substance is a varnish (11).

[0057] 6. A method according to any one of the items 2-5, wherein the coating is a glossy coating (12).

[0058] 7. A method according to items 1, wherein the coating (17) is non-curable or only curable to a limited extent by the irradiation, whereas the substance (19) makes the coating curable by the irradiation at locations where they meet each other.

[0059] 8. A method according to items 7, wherein the substance comprises a photo-initiator (19).

[0060] 9. A method according to items 7 or 8, wherein the substance is a first substance (19) and wherein a second substance (21) is digitally printed locally on the upper side (3) adjacent to the first substance (19), which second substance (21) inhibits curing of the coating (17) at locations where they meet each other such that the coating (17) remains liquid there.

[0061] 10. A method according to item 9, wherein the second substance comprises a UV absorber (21), such as an electron scavenger or an anti-oxidant so as to inhibit propagation of radicals.

[0062] 11. A method according to item 9 or 10, wherein the first and second substances (19, 20) are printed synchronously.

[0063] 12. A method according to any one of the items 7-11, wherein remaining liquid (17) is removed from the upper side (3) after the step of irradiating the upper side (3).

[0064] 13. A method according to any one of the items 7-12, wherein the substance (19) is printed after applying the coating (17) on the upper side (3).

[0065] 14. A method according to any one of the preceding items, wherein the substrate (2) is made of a wood-based material, preferably MDF or HDF, or a plastic-based material, preferably PVC or PP, or mineral-based, preferably MgO, or cement.

[0066] 15. A method according to any one of the preceding items, wherein the step of irradiating comprises UV irradiating (14).

[0067] 16. A method according to any one of the preceding items, wherein a decor (8) is applied on the upper side (3) before the step of applying the layer (11, 12, 17, 19, 21).

[0068] 17. A method according to item 16, wherein the decor (8) is printed directly onto the upper side (3).

[0069] 18. A method according to item 17, wherein the decor (8) is at least partly cured before applying the layer (11, 12, 17, 19, 21).

[0070] 19. A method according to any one of the items 16-18, wherein a primer (5), or any alternative basecoat, is applied onto the upper side (3) before applying the decor (8).

[0071] 20. A method according to item 19, wherein the primer (5) is at least partly cured before applying the decor (8).

[0072] 21. A method according to item 16, wherein the decor is applied by means of a decorative layer which is attached to the substrate, for example a printed paper or plastic foil.

[0073] 22. A method according to any one of the preceding items, wherein the coating (12, 17) is transparent.