PROCESS FOR THE APPLICATION OF A COVERING LAYER TO A POLYMERIC PRODUCT, DEVICE FOR CARRYING OUT SAID PROCESS AND PRODUCT MADE WITH SAID PROCESS

Abstract

Process for the application of a covering layer to a polymeric product (10), in particular a sheet or a panel, comprising the steps of: —providing a planar substrate (11) of polymeric material, with an ink layer (12) deposited on a surface of said planar substrate (11) to define a printing pattern; —applying, above said ink layer (12), an interface layer in a respective application station (3); —applying a covering layer (14) of transparent polymeric material, above said interface layer and as a protection of the printing pattern in a respective rolling station (4).

Claims

1. A process for the application of a covering layer to a polymeric product, in particular a sheet or a panel, comprising the steps of: providing a planar substrate of polymeric material, with an ink layer deposited on a surface of said planar substrate to define a printing pattern; applying, above said ink layer, an interface layer; applying a covering layer of transparent polymeric material, above said interface layer and as a protection of the printing pattern.

2. The process according to claim 1, wherein said interface layer comprises at least one adhesive substance.

3. The process according to claim 2, wherein said adhesive substance is a polymerizable adhesive substance, the process further comprising a step of polymerizing said interface layer.

4. The process according to claim 3, wherein said step of polymerizing the interface layer is subsequent to the step of applying the covering layer.

5. The process according to claim 4, wherein in said step of polymerizing the interface layer it is exposed to an ultraviolet light.

6. The process according to claim 1, wherein said planar substrate and the covering layer are both made of polyvinylchloride.

7. The process according to claim 1, wherein said step of applying the covering layer is made by rolling.

8. The process according to claim 7, wherein said rolling that applies the covering layer is a cold rolling.

9. The process according to claim 1, wherein said ink layer comprises a U.V. ink.

10. The process according to claim 1, wherein the interface layer is applied through an application roller.

11. The process according to claim 1, wherein said step of providing the planar substrate comprises a step of digital printing in which the ink layer is deposited, said step of digital printing being carried out in-line with the subsequent steps of applying the interface layer and of applying the covering layer.

12. A device for applying a covering layer to a polymeric product, in particular a sheet or a panel, comprising: means for moving forward a planar substrate of polymeric material, with an ink layer deposited on a surface thereof to define a printing pattern, along a forward direction; an application station for applying an interface layer above said planar substrate; and a rolling station for rolling a covering layer of transparent polymeric material on the planar substrate placed downstream of said application station.

13. The device according to claim 12, further comprising a digital printer for depositing the ink layer above the forward-moving planar substrate, placed in-line downstream of said application and rolling stations.

14. A polymeric product, in particular a sheet or a panel, comprising: a planar substrate of polymeric material; an ink layer defining a printing pattern directly in contact with a surface of said planar substrate; a covering layer of transparent polymeric material placed above said ink layer and as a protection of the printing pattern; and an interface layer interposed between the ink layer and the covering layer.

15. The polymeric product according to claim 14, wherein said ink layer comprises a U.V. ink and said interface layer comprises a polymerizable adhesive.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG. 1 shows a schematic view, with altered proportions in order to highlight the aspects of interest, of a polymeric product, in particular a PVC sheet, made according to the prior art;

[0048] FIG. 2 shows a schematic view, with altered proportions in order to highlight the aspects of interest, of a polymeric product, in particular a PVC sheet, made according to the present invention;

[0049] FIG. 3 schematically illustrates a device for implementing the process for applying the covering layer according to the present invention.

DETAILED DESCRIPTION

[0050] With reference to the attached FIG. 3, reference number 100 wholly indicates a device for the application of a covering layer to a polymeric product 10, in particular a PVC sheet.

[0051] In the following description, terms such as on, under, below, upper, or derivatives thereof are to be intended with reference to the normal configuration of use of the device 100 illustrated in the above-mentioned figure.

[0052] The device 100 provides forward means, not represented since they are per se known, for moving forward a PVC planar substrate 11, of a neutral colour (for instance white), along the different process stations.

[0053] A first process station is represented by a digital printer 1, schematically illustrated in the above figure.

[0054] In a per se known manner the digital printer has one or more printing modules, for instance four printing modules relating to the different colours of a four-color printing. Each module comprises one or more printing heads arranged to release ink drops onto the planar substrate 11 which passes there below.

[0055] In the decoration process according to the prior art, a printing pattern is thus made on the upper surface of the planar substrate 11. The printing pattern is identified in the present description as an ink layer 12.

[0056] The above printing pattern may represent for instance a wooden, stone or metal appearance, so that the resulting polymeric sheet will constitute the decorative coating for instance of a flooring vinylic panel.

[0057] The inks dispensed by the digital printer 1 are preferably U.V. inks, and a fixing station 2 for fixing the colour constituted in this case by an ultraviolet light lamp is consistently placed at the exit.

[0058] A different fixing station 2 may be provided according to the type of ink used. In the case of a water-based ink, for instance, a drying station may be provided. The drying station may be constituted, in a per se known manner, by a hot air oven or an I.R. dryer.

[0059] Downstream of the fixing station 2 an application station 3 for applying an interface layer 13 is provided. Said station may be formed by an application roller and an opposite return roller, wherein the application roller is fed with a polymerizable adhesive substance that constitutes the above interface layer 13.

[0060] At this station, the process thus provides for the application of the interface layer 13, which covers the planar substrate 11 by overlapping the printing pattern defined by the ink layer 12.

[0061] Subsequently to the application station 3 a rolling station 4 is provided, which is constituted in a per se known manner by two rolling calenders.

[0062] In this station, the process provides for the coupling to the planar substrate 11 of a covering layer 14, fed continuously. The covering layer 14 in the present embodiment is a PVC transparent film, that protects the previously made printing pattern. The interface layer 13 is that between the planar substrate 11 and the covering layer 14, as visible in FIG. 2.

[0063] Finally, the device provides a last polymerization station 5 for polymerizing the interface layer 13, placed at the exit of the above rolling rollers 4.

[0064] The polymerization station 5 may be an ultraviolet light lamp. Preferably, for the polymerization station 5 a LED lamp is used, which concentrates the peak of power to a specific wavelength, comprised between 385 nm and 405 nm according to the project choices. Actually, it has been verified that PVC, generally impermeable to ultraviolet light, has a minimum permeability around said wavelengths.

[0065] In the polymerization station 5 a polymerization step for polymerizing the interface layer is carried out, in which the adhesive substance used reticulates, thus defining an integral and stable coupling between planar substrate 11 and covering layer 14, though the interposed presence of U.V. ink drops.

[0066] Obviously, a skilled person can make several changes and variants to the above described invention, in order to meet contingent and specific needs, all of them by the way contained in the scope of protection of the invention as defined by the following claims.