METHOD FOR MANUFACTURING A PANEL

Abstract

A method may be provided for manufacturing a panel of the type having a support and a top layer. The top layer may have a printed motif and a wear layer disposed above the motif. The wear layer may be fabricated from PVC. The top layer may include an inkjet receiving layer that has less than 10% by weight of water absorbing substances. The method may involve providing a printing substrate, providing the printing substrate with the inkjet receiving layer, and digitally inkjet printing the motif with a set of water based inks. The digital inkjet printing may involve one or more printing operations. Each of the printing operations may be dedicated to print one color. The method may involve one or more ink drying steps. Each of the drying steps may be performed after performing one or more respective printing operations.

Claims

1. A method for manufacturing a panel having a support and a top layer, the top layer having a printed motif and a wear layer disposed above the printed motif, the wear layer including PVC, the top layer having an inkjet receiving layer the includes less than 10% by weight of water absorbing substances, the method comprising: providing a printing substrate; providing printing substrate with the inkjet receiving layer; inkjet printing motif with a set of water-based inks; wherein the digital inkjet printing includes one or more printing operations, each of the printing operations being dedicated to print one; and one or more ink drying steps, wherein each of the ink drying steps is performed after performing one or more respective printing operations.

2. The method of claim 1, wherein the set of water-based inks comprises multiple colors; and wherein each ink drying step is performed after printing a correspondent ink.

3. The method of claim 1, wherein the inkjet receiving layer is free from water absorbing substances.

4. The method according to claim 1, wherein the inkjet receiving layer comprises a multivalent metal salt or an acid component.

5. The method according to claim 4, wherein the inkjet receiving layer comprises between 30 and 80% of multivalent metal salt.

6. The method according to claim 1, wherein the inkjet receiving layer comprises a water-based dispersion of terpolymer vinyl chloride, vinyl acetate ethylene, a water-based dispersion of copolymer vinyl chloride, vinyl acetate, a water-based aliphatic PU dispersion, a water-based acrylic dispersion, a water-based styrene acrylic dispersion, or combinations thereof.

7. The method according to claim 1, comprising providing an adhesion layer between the printed motif and the wear layer.

8. The method according to claim 7, wherein the adhesion layer comprises a water-based dispersion of terpolymer vinyl chloride, vinyl acetate ethylene, a water-based dispersion of copolymer vinyl chloride, vinyl acetate, a water-based aliphatic PU dispersion, a water-based acrylic dispersion, a water-based styrene acrylic dispersion, or combinations thereof.

9. The method according to claim 1, wherein the printed motif is printed directly on the support of the panel.

10. The method according to claim 1, wherein the printed motif is printed on a thermoplastic foil that is subsequently attached to a substrate.

11. The method according to claim 1, wherein the water-based ink comprises a binding agent.

12. The method according to claim 11, wherein the binding agent of the water-based ink is VC-VAC copolymer or polymer latexes, either acrylates or urethane dispersion or combinations thereof.

13. The method according to claim 11, wherein the binding agent of the ink shows a MFFT below 60° C.

14. The method according to claim 1, wherein the digital inkjet printing is performed at a temperature above room temperature.

15. The method according to claim 1, wherein each of the ink drying steps is performed via NIR pins.

16. A method for manufacturing a thermoplastic foil printable with an inkjet printer for use as a decor foil in a laminate panel, the method comprising: providing a thermoplastic foil; and coating at least one side of the thermoplastic foil with an inkjet receiving layer; wherein the inkjet receiving layer has a content of water absorbing substance below 10% wt.

17. The method according to claim 16, wherein the water absorbing substance comprises pigments.

18. The method according to claim 17, wherein the inkjet receiving layer comprises a water-absorbing particle content below 5% wt.

19. The method according to claim 16, wherein the inkjet receiving layer comprises polymeric binder.

20. The method according to claim 19, wherein the polymeric binder comprises a water-based dispersion of terpolymer vinyl chloride, vinyl acetate ethylene, water-based dispersion of copolymer vinyl chloride, vinyl acetate, water-based aliphatic PU dispersion, non-blocking water-based acrylic dispersions, a water-based styrene acrylic dispersion, or combinations thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0057] With the intention of better showing the characteristics according to the invention, in the following, as an example without limitative character, an embodiment is described, with reference to the accompanying drawings, wherein:

[0058] FIG. 1 shows in perspective a panel according to the invention;

[0059] FIG. 2 shows a view according to the line II-II indicated on FIG. 1;

[0060] FIG. 3 on a larger scale provide a view on the area F3 illustrated in FIG. 1;

[0061] FIG. 4 shows some steps in a method for forming the panel of FIG. 1;

[0062] FIG. 5 shows some steps in an alternative method for forming the panel of FIG. 1;

[0063] FIG. 6 schematically shows a side view of a printer operated in single-pass mode on a central cylinder.

DESCRIPTION OF NON-LIMITING EMBODIMENTS

[0064] FIG. 1 illustrates a decorative panel 1 comprising a substrate 2 made of a thermoplastic material, preferably rigid PVC in the form of the so called SPC and a top layer 3 provided with a printed motif 4, in this case imitating a wood decor. The panel 1 can have the shape of a rectangular and oblong floor panel, with a pair of long sides 5 and a pair of short sides 6. In this case the panel 1 is provided at least at the long sides 5 with coupling means 7 allowing to lock the respective sides 5 together with the sides of a similar panel both in a direction R1 perpendicular to the plane of the coupled panels, as in a direction R2 perpendicular to the coupled sides and in the plane of the coupled panels. As illustrated in FIG. 2 such coupling means or coupling parts can basically have the shape of a tongue 8 and a groove 9, provided with additional cooperating locking means 10 allowing for said locking in the direction R2.

[0065] FIG. 2 and FIG. 3 show that the top layer 3 comprises a decorative foil 11 and a wear layer 12 provided on top of the decorative foil 11. The decorative foil 11 comprises a thermoplastic foil 13 for example made of PVC, and the digitally printed decor 4. The decorative foil 11 further comprises an inkjet receiving layer 14. In the example the inkjet receiving layer comprises a binder and is free from any water absorbing substance. The binder preferably comprises water-based dispersion of terpolymer vinyl chloride, vinyl acetate ethylene; water-based dispersion or copolymer vinyl chloride, vinyl acetate; water-based aliphatic PU dispersion; other non-blocking water-based acrylics dispersions. The inkjet receiving layer further comprise a cross linker, a metal salt and other additives like dispersant, coupling agent, wetting agent or PH modifiers.

[0066] In the example, the wear layer 12 is a transparent thermoplastic foil, preferably made of PVC.

[0067] Between the decorative foil 11 and the wear layer 12 is provided an adhesion layer 15 comprising water-based dispersion of terpolymer vinyl chloride, vinyl acetate ethylene; water-based dispersion or copolymer vinyl chloride, vinyl acetate; water-based aliphatic PU dispersion; other non-blocking water-based acrylics dispersions, thereby strongly improving lamination between the decorative foil and the wear layer.

[0068] FIG. 4 shows some step of a method for manufacturing the panel 1. In the method is illustrated a step 51 of providing the thermoplastic foil 13 by uncoiling it from a first roll 16. The foil 13 is then provided, on at least one surface, with the inkjet receiving layer 14, for example with a doctor blade or a sprayer, in a step S2.

[0069] The coated foil 13 is then printed (step S3) in a single pass printer 20 using water-based ink. The ink comprises a binding agent having preferably a MFFT below 40° C. for example the binding agent are VC-VAC copolymer or polymer latexes, either acrylates or urethane components, dispersion or combinations thereof.

[0070] After printing, the obtained decorative foil 11 is coiled again in a second roll 17 and then stocked, as indicated in step S4.

[0071] For the production of the panel 1, the decorative foil 11 can be uncoiled from second roll 17 in a step S5 and then coated with the adhesion layer 15 in a step S6. The decorative foil 11 can then be cut into sheets 18, in a step S7. The sheets 18 are then sandwiched between a support 2 and a wear layer 12 and then thermally laminated to form the panel 1.

[0072] In FIG. 5 it is shown an alternative method that differs from that of FIG. 4 in that after printing step S3 the decorative foil 11 is immediately coated with the adhesion layer 15 and then laminated onto the substrate 2. In this case, the printing line can be in line with a support manufacturing equipment, not show, for example an extruder.

[0073] FIG. 6 illustrates that the foil 13 having the inkjet receiver coating 14 may be printed by means of an inkjet printer 20, which, in this example comprises a central cylinder 21 upon which the foil 13 is partially wound and several printing units 22, each comprising one or more print heads, disposed radially around the central cylinder 21 and over the area of the foil 13 to be printed. The printer 20, in this example, relates to a printer of the single pass type, wherein the provision of the printed motif involves a relative motion of said inkjet printer 20, more particularly the printing unit 22, and said foil 13 during printing in a printing direction D. In this case, the printing unit 22 and the print heads are at standstill, while the foil 13 moves during ejection of inks onto the foil 13, more precisely onto the inkjet receiver coating 14 applied to the foil 13. The foil 13 gets printed during a single continuous movement of the foil 13 itself relative the printer 20.

[0074] Preferably each printing unit 22 is configured for printing only one color. Preferably each printing unit 22 extends above the entire width of the foil 13 to be printed. For example, each printing unit is composed by a so called colorbar.

[0075] In the embodiment illustrated in the example the printer 20 is provided with a plurality of NIR pins 23 each disposed after a respective printing unit 22 so that each pin 23 immediately dries the ink just printed by the respective printing unit 22. In the example the central cylinder 21 comprises a heating device 24 to heat the foil 13 during printing to further help drying of the ink. Preferably the printing operation is performed at a temperature above external environment temperature but, in any case, below 100° C. to prevent deformation of the foil.

[0076] In the example each printing unit comprises an ink recirculating circuit 25 configured to recirculate a flow of ink 10 ml/min or more.

[0077] It is generally noted that the dimensions of the represented top layer 3 and its components is, in the figures, drawn out of scale in order to better illustrate the invention.

[0078] The invention is further disclosed by the following paragraph list as defined by the below numbered items. [0079] 1. A method for manufacturing a panel of the type comprising a support and a top layer, wherein the top layer comprises a printed motif and a wear layer disposed above said motif, wherein said wear layer comprises PVC, the top layer comprising an inkjet receiving layer and said inkjet receiving layer comprising less than 10% by weight of water absorbing substances, wherein the method comprises the step of providing a printing substrate, the step of providing said printing substrate with said inkjet receiving layer, the step of digitally inkjet printing said motif with a set of water based inks, and wherein said step of digital inkjet printing comprises one or more printing operations, each of said printing operations being dedicated to print one color, characterized in that the method comprises one or more ink drying step, wherein each of said drying steps is performed after performing one or more respective printing operations. [0080] 2. The method of item 1, wherein said set of inks comprises multiple color, and wherein each ink drying step is performed after printing a correspondent ink. [0081] 3. The method of item 1, wherein the inkjet receiving layer is free from water absorbing substances. [0082] 4. The method according to any of the preceding items, wherein the inkjet receiving layer comprises a multivalent metal salt or an acid component. [0083] 5. The method according to item 4, wherein the inkjet receiving layer comprises between 30 and 80% of multivalent metal salt. [0084] 6. The method according to any of the preceding items, wherein the inkjet receiving layer comprises a water-based dispersion of terpolymer vinyl chloride, vinyl acetate ethylene, water-based dispersion of copolymer vinyl chloride, vinyl acetate or water-based aliphatic PU dispersion or a water-based acrylic dispersion or a water-based styrene acrylic dispersion or combinations thereof. [0085] 7. The method according to any of the preceding items, wherein it comprises the step of providing an adhesion layer between the printed motif and the wear layer. [0086] 8. The method according to item 7, wherein the adhesion layer comprises a water-based dispersion of terpolymer vinyl chloride, vinyl acetate ethylene, water-based dispersion of copolymer vinyl chloride, vinyl acetate or water-based aliphatic PU dispersion or water-based acrylic dispersion or a water-based styrene acrylic dispersion or combinations thereof. [0087] 9. The method according to any of the preceding items, wherein the printed motif is printed directly on the support of the panel. [0088] 10. The method according to any of the items from 1 to 8, wherein the printed motif is printed on a thermoplastic foil subsequently attached to a substrate. [0089] 11. The method according to any of the preceding items, wherein the ink comprises a binding agent. [0090] 12. The method according to item 11, wherein the said binding agent of the ink is VC-VAC copolymer or polymer latexes, either acrylates or urethane dispersion or combinations thereof. [0091] 13. The method according to item 11 or 12, wherein the said binding agent of the ink shows a MFFT below 60° C., preferably below 40° C. [0092] 14. The method according to any of the preceding items, wherein the printing step is performed at a temperature above room temperature. [0093] 15. The method according to any of the preceding items, wherein each drying step is performed via NIR pins. [0094] 16. A method for manufacturing thermoplastic foil printable with an inkjet printer for use as a decor foil, in a laminate panel, wherein the method at least comprises the following steps: [0095] the step of providing a thermoplastic foil; [0096] the step of coating at least one side of said foil, with an inkjet receiver coating; wherein said inkjet receiving coating comprises a content of water absorbing substance below 10% wt. [0097] 17. The method according to item 16, wherein said water absorbing substance comprises pigments, in particular minerals, like silicate or aluminum silicates, for example talc, clays, calcined clays, kaolin, silica. [0098] 18. The method according to item 16 or 17, wherein the inkjet receiving layer comprises a water-absorbing particle content below 5%, preferably below 1%, more preferably is free from water-absorbing particles. [0099] 19 The method according to any of the items from 16 to 18, wherein the inkjet receiver layer comprises polymeric substance, also called binder, preferably a thermosetting substance. [0100] 20.The method according to item 19, wherein the binder comprises water-based dispersion of terpolymer vinyl chloride, vinyl acetate ethylene; water-based dispersion or copolymer vinyl chloride, vinyl acetate; water-based aliphatic PU dispersion; other non-blocking water-based acrylics dispersions or a water-based styrene acrylic dispersion or combinations thereof. [0101] 21.The method according to item 19, wherein polymeric substance in said inkjet receiver coating at least or mainly polyvinyl alcohols are used. [0102] 22.The method according to item 19, wherein the polymeric substance in said inkjet receiver coating polyvinyl acetates, ethylvinylacetates, block copolymers based on polyvinylacetate, block copolymers based on polyvinylalcohol, acrylates, latexes, polyvinyl derivaties, VCVAC derivatives, polyurethanes based on polyols and isocyanates, polyurethanes based on polycarbamates and polyaldehydes, e.g. both as a waterbaseddispersion/emulsion or a waterbased or solvent solution. [0103] 23. The method according to any of the items from 19 to 22, wherein the ink receiver coating comprises a crosslinking agent for the crosslinking reaction of the polymeric substance itself. [0104] 24. The method according to any of the items from 16 to 23, wherein the inkjet receiver coating comprises a dispersant, preferably polycarboxylates, polyphosphates, a polyionic polymer, preferably polyDADMAC (Polydiallyldimethylammonium chloride) polyamine or alumina salts. [0105] 25. The method according to item 24, wherein the inkjet receiver coating is provided with less than 10%, more preferably less than 5% based on dry coating weight of dispersant, for example between 5 and 0.1%. [0106] 26. The method according to any of the items from 16 to 25, wherein the inkjet receiver coating comprises a flocculant, preferably a metal salt, preferably a cationic metal salt. [0107] 27. The method according to item 26, wherein the inkjet receiver coating is provided with 20 to 60%, based on dry coating weight of flocculating agent, in particular of metal salt. [0108] 28. The method according to any of the items from 16 to 27, wherein the inkjet receiving coating is acidic, preferably it comprises one or more organic or inorganic acid component, for example citric acid, formic acid, lactic acid, propionic acid or a combination thereof. [0109] 29. The method according to any of the items from 16 to 28, wherein the thermoplastic foil onto which the inkjet receiver coating is applied has a base weight of 50 to 100 grams per square meter, e.g. between 60 and 80 grams per square meter. [0110] 30. The method according to any of the items from 16 to 29, wherein the thermoplastic foil is as polyvinylchloride (PVC) foil, polypropylene (PP) foil, polyethylene (PE) foil, polyethylene-terephthalate (PET) foil or thermoplastic polyurethane (TPU). [0111] 31. The method according to item 19, wherein thermoplastic foil is made of PVC and the binder for use on such thermoplastic foils is polyurethane based, acrylate based, or polyvinyl acetate based. [0112] 32. The method according to any of the items from 16 to 31, wherein said inkjet receiver coating is applied in one step in order to form a unique layer having the inkjet receiving coating composition [0113] 33. The method according to any of the items from 16 to 32, wherein said inkjet receiving coating is a liquid substance which is deposited on said foil, preferably the liquid substance is a water-based suspension of at least said binder. [0114] 34. The method according to item 33, wherein the deposition of the liquid substance for the ink receiving coating is performed in a rotogravure coating line or, alternatively, on the printing equipment, immediately before the printing operation. [0115] 35. The method according to item 34, wherein in case the coating is wholly or partially done on a printing equipment for printing a pattern, the printing equipment is preferably roll-to-roll or a roll-to-sheet printer, comprising a coating device upstream of the print heads, for example a gravure coater and/or additional printing heads suitable for printing the liquid substance for the respective sublayer of the inkjet receiver coating. [0116] 36. The method according to item 35, wherein said additional printing heads, for example an additional row of printing heads, may have nozzles with a larger diameter than those used for the actual printing of the pattern, preferably resolution of 1 to 100, or even 1 to 25 dots per inch may suffice for these nozzles. [0117] 37. A thermoplastic foil for inkjet printing, wherein said foil at least at one side is provided with an inkjet receiver coating having an absorbing substance content below 10% wt, preferably said inkjet receiver coating is free from any water absorbing substance. [0118] 38. A method for manufacturing a panel of the type comprising a support and a top layer, wherein the top layer comprises a printed motif, wherein said printed motif is provided on a printable substrate having an inkjet receiver coating having an absorbing substance content below 10% wt, preferably said printable substrate is a thermoplastic foil according to item 37 or obtained in a method according to any of the items from 16 to 36, wherein the motif is printed by means of an inkjet printer, preferably using water-based inks or hydro-UV inks. [0119] 39. The method according to item 38, wherein the foil is attached to said substrate material by means of a hot-pressing treatment, for example thermal lamination. [0120] 40. The method according to item 38 or 39, wherein said ink comprises a binder, preferably said binder comprises VC-VAC copolymer or polymer latexes, either acrylates or urethane components dispersion or combinations thereof and/or preferably said binder shows a MFFT below 60° C., more preferably below 50° C., for example 40° C. or less. [0121] 41. The method according to any of the items from 38 to 40, wherein the step of printing is performed at a temperature above external environment temperature, for example below 100° C., preferably below 60° C. [0122] 42. The method according to any of the items from 38 to 41, wherein after printing the ink is dried to remove water or vehicle residues, preferably multiple drying steps to dry one or more inks are performed, for example, in case of printing a set of inks, preferably a set of colored inks, drying step dedicated do each color is performed. [0123] 43. The method according to item 42, wherein after each printing head or printing unit a drying unit is provided, for example a drying NIR (Near Infra-Red) pin, to perform one drying step between the printing units. [0124] 44. The method according to any of the items from 41 to 43, wherein during printing, the foil is placed on a heated support, for example a heated printing drum. [0125] 45. The method according to any of the items from 38 to 44, wherein the top layer comprises a wear layer disposed above said motif, wherein said wear layer preferably comprises PVC. [0126] 46. The method according to any of the items from 38 to 45, wherein the top layer is provided with a first adhesion layer between the motif and the top layer and/or a second a adhesion layer between the foil and the substrate. [0127] 47. The method according to the item 46, wherein the first and/or second adhesion layer comprises, or is formed by, the same substance forming the binder of the ink receiving layer. [0128] 48. The method according to the item 46 or 47, wherein the first and/or second adhesion layer comprises a water-based dispersion of terpolymer vinyl chloride, vinyl acetate ethylene; water-based dispersion or copolymer vinyl chloride, vinyl acetate; water-based aliphatic PU dispersion; other non-blocking water-based acrylics dispersions or a water-based styrene acrylic dispersion or combinations thereof. [0129] 49. The method according to any of the items from 45 to 48, wherein the wear layer is applied above the printed motif after printing, e.g. by way of a plastic thermoplastic foil or a liquid coating, preferably while the printed foil is laying on the substrate, either loosely or already connected or adhered thereto. [0130] 50. The method according to any of the items from 38 to 49, wherein the method comprises a step of embossing the upper surface of the panel, for example by embossing the wear layer and/or the printed foil, preferably the embossing step is performed before, after or during thermal lamination of the thermoplastic foils on the substrate or alternatively it is possible that the wear layer is provided with an embossed structure. [0131] 51. The method according to any of the items from 38 to 50, wherein the printing operation is performed directly on the support, for example wherein the printable substrate is the support or wherein a blank printable foil is attached on the support before printing. [0132] 52. The method according to any of the items from 38 to 51, wherein the printable substrate is made of a thermoplastic material. [0133] 53. The method and or the foil according to any of the preceding items, wherein the foil of the invention may be a colored, pigmented and/or dyed base foil [0134] 54. The method and or the foil according to any of the preceding item, wherein the ink receiving layer is colored or pigmented with colored pigments.

[0135] The present invention is in no way limited to the above described embodiments, but such methods, thermoplastic foils and panel may be realized according to several variants without leaving the scope of the invention.