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EP-4382214-B1 - A METHOD OF MANUFACTURING A PANEL

EP4382214B1EP 4382214 B1EP4382214 B1EP 4382214B1EP-4382214-B1

Inventors

  • VERMEULEN, BRUNO
  • CLEMENT, BENJAMIN

Dates

Publication Date
20260506
Application Date
20211222

Claims (15)

  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 the coating (12) and the substance (11) react with each other, characterized in that 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.
  2. A method according to claim 1, wherein the coating (12) and the substance (11) already start to react with each other before the step of irradiating.
  3. A method according to claim 1 or 2, wherein the substance (11) has a higher surface tension than the coating (12).
  4. A method according to any one of the preceding claims, wherein the substance is a varnish (11).
  5. A method according to any one of the preceding claims, wherein the coating is a glossy coating (12).
  6. A method according to claim 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.
  7. A method according to claim 6, wherein the substance comprises a photo-initiator (19).
  8. A method according to claim 6 or 7, 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.
  9. A method according to claim 8, 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.
  10. A method according to claim 8 or 9, wherein the first and second substances (19, 20) are printed synchronously.
  11. A method according to any one of the claims 6-10, wherein remaining liquid (17) is removed from the upper side (3) after the step of irradiating the upper side (3).
  12. A method according to any one of the preceding claims, 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.
  13. A method according to any one of the preceding claims, wherein the step of irradiating comprises UV irradiating (14).
  14. A method according to any one of the preceding claims, wherein a decor (8) is applied on the upper side (3) before the step of applying the layer (11, 12, 17, 19, 21), preferably wherein the decor (8) is printed directly onto the upper side (3).
  15. A method according to any one of the preceding claims, wherein the coating (12, 17) is transparent.

Description

The present invention relates to a method of manufacturing a panel, comprising the steps of supplying a substrate having an upper side, applying a layer onto the upper side and subsequently irradiating the upper side so as to cure at least a part of the layer by irradiation, hence forming the panel. Such a method of manufacturing a panel is known from WO 2021/214659 A1, US 2015/030817 A1 and EP 3 865 308 A1. An object of the invention is to provide an efficient method of manufacturing a panel for covering a floor, a wall, a ceiling or furniture. This object is achieved by the subject-matter of claim 1. Advantageous further developments are subject-matter of the dependent claims. An advantage of the present invention is that it provides an efficient method to create a textured surface at the upper side of the resulting panel. Digital printing of the substance provides the opportunity to print the substance in numerous different possible patterns and to control the velocity of the printed substance. Digital printing may be performed by inkjet printing, for example. The resulting panel may be suitable for a floor, wall or ceiling covering or alternative coverings. It may also be a panel that is suitable for furniture, or the like. According to the invention the substance is printed as a liquid on the upper side before the coating is applied, whereas the substance and the coating have different surface tensions and react with each other, provides the opportunity to influence the surface structure of the upper surface of the coating. Due to the different surface tensions between the coating and the substance they repel each other, creating a finely textured upper surface at regions where the substance is printed, i.e. a microstructure. This results in a tactile and visual effect which distinguishes areas where the substance is printed from areas where the substance is not printed. It is noted that variations in substance thickness and coating thickness may vary the final result of the tactile and visual effect. The coating and the substance may cooperate with each other such that the substance penetrates or partly penetrates into the coating. When the word 'liquid' is used herein, it may cover a wide range of viscosities. For example, a pasty material is also regarded as being a liquid. The coating and the substance may already start to react with each other before the step of irradiating. The substance may have a higher surface tension than the coating. The surface tensions of the coating and the substance may be varied by selecting the chemical nature of their base raw materials and by adding specific additives. For example, resins containing polar groups as hydroxyl, amines and aromatic groups will have a surface tension higher than resins containing linear structures of hydrocarbon type. Additives reducing the surface tension may be: silicones, polyether silicones, acrylate silicones, polyether silicones acrylates, fluorinated surfactants, alkoxylated alcohols. Additives increasing the surface tension may be: amines, polyethers macromers-modified polyacrylates, silicon and polyethers macromers-modified polyacrylates. The substance may be a liquid that contains a photo crosslinking resin, for example (meth) acrylate and/or vinyl monomers and/or acrylate oligomers. The substance may be a varnish. Varnishes serve many purposes, for example to be used as a protectant. The varnish may contain water and/or solvents to control its viscosity. Preferably the coating is a glossy coating, such that the textured upper surface of the resulting panel at areas where the substance is applied, create a great contrast against a higher gloss. The surrounding areas of the glossy coating which do not contain the substance remain smooth and glossy, creating a tactile and visual contrast between the areas with and without the printed substance. The coating may have various chemical nature, for example a polyurethane, epoxy, photo-crosslinking, acrylated, acrylic resin or the like. Photo-crosslinking resins have in common the fact of polymerizing and hardening thanks to the energy irradiated by ultraviolet ray devices and/or by irradiation with EB (Electron Beam) and are divided in different types based on the cross-linking mechanism: 1) radical resins, typically from vinyl monomers and acrylate resins that are divided in different subcategories: epoxy-acrylate, urethane- acrylate, polyester-acrylate, polyether-acrylate, amino-acrylate, silicon-acrylate, polyisoprene- acrylate, polybutadiene acrylate and acrylate monomers. Among the vinyl monomers can be cited N-vinyl caprolactame (NVC), acryloyl morpholine (ACMO), diethylene glycol divinyl ether (DVE-2), triethylene glycol divinyl ether (DVE-3) and mixtures thereof. 2) cationic resin such as epoxy resin, polyols and monomers such as oxetanes and vinyl ethers. The coating may be applied by means of inkjet printing, screen printing, roller printing, spraying, curtain coating or the