METHOD FOR MANUFACTURING A DECOR SHEET FOR DECORATIVE PANEL

Abstract

A method is provided for manufacturing a printed dcor sheet. The method may involve providing a first printable or printed substrate. At least one predetermined operation may be performed on the substrate, wherein the predetermined operation causes the deformation of the substrate in at least one direction. The deformation may be measured to obtain at least one deformation parameter. A first master image may be provided. An image processing operation may be performed on the first master image to obtain a second master image. The second master image may be printed on a second printable substrate to obtain the dcor sheet. The image processing operation may involve at least modifying the first master image on the basis of the at least one deformation parameter.

Claims

1. A method for manufacturing a printed decorative layer the method comprising: providing a first printable or printed substrate; wherein the first printable or printed substrate includes a paper layer; performing at least one predetermined operation on the first substrate, wherein the predetermined operation causes a deformation of the first substrate in at least one direction; measuring the deformation to obtain at least one deformation parameter; providing a first master image; performing an image processing operation on the first master image to obtain a second master image; printing the second master image on a second printable substrate to obtain the decorative laver; wherein the image processing operation involves at least modifying the first master image on the basis of the at least one deformation parameter.

2. The method according to claim 1, wherein the at least one deformation parameter is a scale parameter; and wherein the image processing operation involves enlarging or reducing one or more dimensions of the first master image on the basis of the at least one deformation parameter.

3. The method according to claim 1, wherein the image processing operation involves deforming the first master image of a deformation that is opposite to the measured deformation.

4. The method according to claim 1, wherein the image processing operation involves modifying the first master image on the basis of at least one modification parameter that is function of the at least one deformation parameter.

5. The method according to claim 1, wherein the image processing operation involves: dividing the first master image into at least two areas; and modifying at least one of the areas.

6. The method according to claim 5, wherein the image processing operation involves modifying each area on the basis of a different modification parameter.

7. The method according to claim 1, further comprising: printing at least a pattern on the first printable substrate.

8. The method according to claim 1, further comprising: printing a plurality of patterns on respective portions of the first printable substrate.

9. The method according to claim 8, wherein each pattern of the plurality is printed with a respective predetermined ink amount.

10. The method according to claim 7, wherein the pattern differs from the first master image.

11. The method according to claim 1, further comprising: identifying a plurality of sectors on the surface of the first printable or printed substrate; and measuring the deformation to obtain at least one deformation parameter for each of the sectors.

12. The method according to claim 1, wherein the predetermined operation is selected from the group comprising: impregnating, heating, pressing, and/or laminating.

13. The method according to claim 1, wherein the printing operation is performed via inkjet printing.

14. The method according to claim 1, wherein the printing is performed via water-based inks.

15. The method according to claim 1, wherein the first printable or printed substrate comprises an ink receiver layer.

16. The method according to claim 1, wherein the second substrate is the same as the first substrate.

17. The method according to claim 1, wherein the second substrate comprises one or more features in common with the first substrate.

18. A method for manufacturing a panel, the method comprising: providing a substrate; attaching a decorative layer obtained from the method according to claim 1 on the substrate.

19. The method according to claim 18, wherein the decorative layer is subject to the predetermined operation.

20. A decorative layer for a decorative panel obtained from the method according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0058] 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:

[0059] FIGS. 1a to 1e schematically show some steps in an image processing operation according to the method of the invention;

[0060] FIG. 2 shows a printed substrate;

[0061] FIG. 3 shows some steps in a method in accordance with the first aspect of the invention;

[0062] FIG. 4 shows some steps in a method in accordance with the first aspect of the invention;

[0063] FIG. 5 shows in perspective a panel obtained by means of the method of FIG. 6;

[0064] FIG. 6 shows some steps of a method for manufacturing a panel in accordance with a second aspect of the invention.

DESCRIPTION OF NON-LIMITING EMBODIMENTS

[0065] FIG. 1 schematically illustrates a first master image 1, in this case representing a wood dcor. In the method according to the invention, the first master image 1 is printed on a first substrate 2. illustrated in FIG. 2, for forming a first printed dcor 3.

[0066] In this example the first substrate 2 comprises a paper sheet 4 having an ink receiver coating 5 on one of its surfaces. The paper sheet 4 comprises a weight of about 70 grams per square meter and a starting Gurley value below 30 s. In the example the ink receiver coating 5 comprises polyvinyl-alcohol as binder, silica particles as pigments and a cationic metal salt chosen from the list consisting of CaCl2, MgCl2, CaBr2, MgBr2, CMA (Calcium Magnesium Acetate), NH4Cl, Calcium Acetate, ZrCl4, calcium nitrate and Magnesium Acetate.

[0067] Said ink receiver coating 5 is provided in a predetermined amount between 0.5 g/sqm and 5 g/sqm on the paper sheet 4.

[0068] The first master image 1 is printed on the first substrate 2 by inkjet printing so to provide on said first substrate an amount of ink between 0.01 gsm and 5 gsm dry weight. Ink is preferably water-based pigment containing ink.

[0069] After printing, the first substrate 2 is subjected to a predetermined operation shown in FIG. 3. In the example, the predetermined operation involves impregnating the first substrate 2 with a thermosetting resin 6, in particular a melamine-based resin. In particular, the first substrate 2 is taken from a starting roll 7 and transported to a first impregnation station 8 where said first substrate 2 is immersed in a bath 9 of said thermosetting resin 6, more particularly a mixture of water and thermosetting resin composition. The first substrate 2 is then allowed to rest while in this case being transported upwards. The resting allows for the resin 6 to penetrate the core of the paper sheet 4. The first substrate 2 then comes into a second impregnation station 10 where the first substrate 2 is, in this case, again immersed in a second bath 11 of resin 6, more particularly a mixture of water and resin. A set of squeezing rollers 12 allows to dose the amount of resin applied to the first substrate 2.

[0070] In the example several doctor blades 13 are available for partially removing resin 6 at the surface of the resin provided first substrate 2.

[0071] The first substrate 2 is then dried and its residual humidity level is brought to below 10%. In the example hot air ovens 14 are used, but alternatively other heating equipment can be used, such as microwave or infrared drying equipment. The first substrate is for example subsequently rolled on a second roller 16 or cut into sheets

[0072] The predetermined operation illustrated in FIG. 3 causes a deformation of the first substrate as illustrated in FIG. 1c. In the example, said deformation comprises an expansion of the first substrate 1 in both a longitudinal Y and a transversal X direction of the first substrate. The example it is also shows that the expansion in the longitudinal direction Y may vary along the transverse direction X.

[0073] Coming back to FIG. 3, after the predetermined operation, in the example after drying, the first substrate 2 is subjected to a measuring step for measuring the deformation and determine at least a deformation parameter DP. Preferably to determine said deformation parameter DP multiple measurement can be performed, by respective measuring devices 15, in particular before and after said predetermined operation, so that the deformation parameter is defined by the difference between said measured values.

[0074] As shown in FIGS. 1b and 1c a plurality of sectors 18 are identified on the surface of said first printable or printed substrate 1, in particular in said first printed dcor 3. Said sectors 18 can be physically identified by printing separating lines on the substrate or by leaving blank areas on the surface of the first substrate 2. Alternatively, the sectors 18 can be only virtually identified. The method involves the step of determining at least one deformation parameter DP for each sector 18.

[0075] In the example, the sectors 18 are disposed in a raster manner on a predetermined number of columns 1, 2, . . . i and on a predetermined number of rows 1, 2, . . . j. For each sector 18 is determined the deformation parameter DP.sub.i.j.

[0076] The deformation parameters DP.sub.i.j are stored in memory of a processing unit PU (shown in FIG. 3), for example a personal computer. Said processing unit PU performs an image processing operation on the first master image 1 that in the example involves identifying multiple areas 19 of said first master image 1 (FIG. 1d), each of them corresponding to a respective sector 1 on the first substrate 2 and involves modifying each area of the first master image 1 on the basis of the respective deformation parameter DP.sub.i.j. In the example each area is modified on the basis of a respective modification parameter MP.sub.i.j that is calculated by the processing unit PU. In the example, the modification parameter MP.sub.i.j for each area is the opposite of the respective deformation parameter DP.sub.i.j: MP.sub.i.j=DP.sub.i.j.

[0077] As a result of said image processing operation a second master image 20 is obtained which is a deformed version of the first master image 1 as shown in FIG. 1e. In particular, with relation to example given, the second master image 20 is smaller than the first master image 1.

[0078] The method then continues as described in FIG. 4. FIG. 4 illustrates that a second substrate 21, for example in form of a paper sheet 4 may be un-winded from a starting roller 22 and coated with the ink receiver coating 5 in a coating station 23. The second substrate 21 is then fed to an inkjet printer 24. The printer 24, in this example, relates to a printer of the single pass type. The inkjet printer 24 is commanded for printing the second master image 20 on the second substrate 21 thereby forming a second printed dcor 25 on said second substrate 21. The printed second substrate 21 is optionally dried in a dryer 26 to finally obtain a printed layer 27 that is subsequently wound up in a second roller 28.

[0079] It is noted that the features of the paper 4, of the ink receiver coating 5, of the ink and of the printing parameters are substantially the same as those involved in the manufacturing of the first printed substrate.

[0080] The obtained printed layer 27 can be used as a decorative layer 27 in a decorative panel 30 as illustrated in FIG. 5. The obtained decorative panels 30 at least comprise a substrate 31, for example of HDF or MDF, and a top layer 32. The top layer 32 comprises the decorative layer formed by the printed layer 27. In the example the decorative panel 30 is a floor panel comprising coupling means 33 on the long and short edges for coupling with adjacent floor panels in a floor covering. As illustrated in FIG. 5 such coupling means or coupling parts 33 can basically have the shape of a tongue and a groove.

[0081] To this aim the printed layer 27 is used in laminate panel manufacturing process, some steps of which are illustrated in FIG. 6. In particular, FIG. 6 shows that the printed layer 27 is subjected to the above-mentioned predetermined operation, in the example is impregnated with a melamine resin 6. Said impregnation is preferably conducted in the same way as for the first substrate and as described in FIG. 3. In FIG. 6, after drying in the oven 14 the printed layer 27 is cut into sheets 29.

[0082] As a result of the said impregnation the printed layer 27 and the printed dcor thereof will deform substantially as predicted with the first printed substrate so to recover the shape and dimension of the first master image 1.

[0083] FIG. 6 further illustrates that a sheet of the impregnated printed layer 27 is taken up in a stack to be pressed in a short daylight press 40 between upper and lower press plates 41-42. Said stack comprises from bottom to top a counter layer 43, a plate shaped substrate 31, the abovementioned resin provided printed layer 27 and a wear layer 44, wherein the counter layer 43 and the wear layer 44 both comprise a paper sheet 45, in case of the wear layer 44 called overlay paper, and resin 6. The stack is then pressed and the press treatment results in a mutual connection between the constituent layers 27-43-44 including the substrate 31, of the stack, as well as in a hardening or curing of the available resin 6. More particularly here a polycondensation reaction of the melamine-based resin takes place, having water as a by-product.

[0084] The upper press plate 41 is a structured press plates having a structure relief 46 that provides a relief in the melamine surface of the panel 30 during the same press treatment, by bringing the structured surface of the upper press plate 41 into contact with the melamine of the wear layer 44. Thanks to the fact that the deformation that occur during the predetermined operation is compensated by the method according to the invention, the relief can be made formed in register with the printed dcor with a increased precision thereby leading to an higher quality of the panel.

[0085] The present invention is in no way limited to the above described embodiments, but such methods, paper layers, panel may be realized according to several variants without leaving the scope of the invention.

[0086] The invention is further disclosed by the following item list as defined by the below numbered items.

[0087] 1. A method for manufacturing a printed decorative layer (27) comprising the steps of: [0088] providing a first printable or printed substrate (2) wherein said first printable or printed substrate (2) comprises a paper layer (4); [0089] performing at least one predetermined operation on said first substrate (2), wherein said predetermined operation causes the deformation of the first substrate (2) in at least one direction (X,Y); [0090] measuring said deformation to obtain at least one deformation parameter (DP); [0091] providing a first master image (1); [0092] performing an image processing operation on said first master image to obtain a second master image (20); [0093] printing said second master image (20) on a second printable substrate (21) to obtain the dcor sheet (27); [0094] characterized in that said image processing operation involves at least modifying the first master image (1) on the basis of said first deformation parameter (DP).

[0095] 2.Method according to item 1, wherein said at least first deformation parameter (DP) is a scale parameter, and in that said image processing operation involves enlarging or reducing one or more dimensions of said first master image (1) on the basis of said least first deformation parameter (DP).

[0096] 3.Method according to item 1 or 2, wherein said image processing operation involves deforming said first master image (1) of a deformation that is opposite to the measured deformation.

[0097] 4.Method according to any of the preceding items, wherein said image processing operation involves modifying the first master image (1) on the basis of at least a modification parameter (MP) that is function of said first deformation parameter (DP).

[0098] 5.Method according to any of the preceding items, wherein said image processing operation involves dividing said first master image (1) into at least two areas (19) and involves modifying at least one of said areas (19).

[0099] 6.Method according to item 5, wherein said image processing operation involves modifying each area (19) on the basis of a different modification parameter (MP).

[0100] 7.Method according to any of the preceding items, wherein it comprises printing at least a pattern on said first printable substrate (2), preferably said pattern corresponding to the first master image (1).

[0101] 8.Method according to any of the preceding items, wherein it comprises printing a plurality of patterns on respective portions of said first printable substrate (2).

[0102] 9.Method according to item 8, wherein each pattern of said plurality is printed with a respective predetermined ink amount.

[0103] 10.Method according to any of the preceding items, wherein said pattern differs from said first master image (1).

[0104] 11.Method according to any of the preceding items, wherein it comprises identifying a plurality of sectors (18) on the surface of said first printable or printed substrate (2) and measuring said deformation to obtain at least one deformation parameter (DP.sub.i.j) for each of said sectors (18).

[0105] 12.Method according to any of the preceding items, wherein said predetermined operation is selected between the group comprising: impregnating, heating, pressing and/or laminating.

[0106] 13.Method according to any of the preceding items, wherein said printing operation is performed via inkjet printing.

[0107] 14.Method according to any of the preceding items, wherein said printing operation is performed via water-based inks.

[0108] 15.Method according to any of the preceding items, wherein said first printable or printed substrate (1) comprises an ink receiver layer (5).

[0109] 16.Method according to any of the preceding items, wherein the second substrate (21) is the same of the first substrate (1).

[0110] 17.Method according to any of the preceding items, wherein the second substrate (21) comprises one or more features in common with the first substrate (2), preferably said feature in common belong to the group comprising: weight, thickness, Gurley value, resin penetration time, ash content.

[0111] 18.Method for manufacturing a panel, preferably a floor, wall, furniture or ceiling panel, comprising the steps of: [0112] providing a substrate (31), preferably wood based substrate; [0113] attaching a decorative layer (27) obtained in the method according to any of the preceding items on said substrate (31).

[0114] 19.The method according to item 18, wherein said decorative layer (27) is subject to said predetermined operation.

[0115] 20.Decorative layer (27) for decorative panel obtained in the method according to any of the items from 1 to 17.