IT202100008192A1 - METHOD TO DECORATE A MATERIAL - Google Patents

Description

FIELD OF APPLICATION

The present invention fits into the technical sector of materials and methods for generating three-dimensionality? and embossing on the surfaces of artefacts, substrates, supports in different types of materials such as panels for the production of floors, coverings, furnishings and more. generally for architecture and design surfaces.

The present invention exploits the combination of both the properties of traditional technologies, which offer high properties? mechanical, chemical-physical and low cost and versatility? digital that allows total customization and high precision.

The present invention relates to a process for making transferable decorations and in particular to a transferable decoration obtained by means of this process.

The process and the transferable decoration, object of the present invention, are introduced in the field of production for the creation of decorations to be transferred, preferably cold, on surfaces of any type, both smooth and rough (such as wood, glass, metal, plastic, plaster, etc.) and in particular for interior architecture such as floors, coverings, furniture, skirting boards, doors and fixtures.

The process and the transferable decoration, object of the present invention, allows to obtain a decorated surface as if it had been printed and finished in the traditional way.

STATE OF ART

Digital printing and in particular inkjet printing is becoming increasingly popular. establishing itself in the industrial sectors by replacing the traditional methods based on analogical printing. The advantages of digital printing are considerable and include the? High flexibility?, the possibility? to produce short runs and the reduction of consumables waste.

In particular, the reproduction of wood on various materials represents a typical application of digital printing for the production of floors, panels for furniture, skirting boards, profiles and in general in the fields of design and architecture.

Typically the materials can consist of wood and derivatives (MDF/HDF/Chipboard/plywood), plastics (PVC/polyolefin), metals, on which the image is printed and which in turn is? normally protected by a varnish in order to increase its resistance to abrasion and scratches.

In particular in the case of floors and panels for furniture, the finishing after printing involves the use of a layer of melamine resin (laminates) or a varnish applied with the normal techniques in use (roller/spray/veil/extruder) . The paint can be of various nature, photo-crosslinkable, epoxy, polyurethane, hot-melt and pu? contain water and/or solvents to control its viscosity.

In the reproduction of natural materials such as wood and stones, in order to obtain a more similar to the original also in touch, in addition to the image? necessary to reproduce also the surface structure

Embossing is normally done on the surface layer and can be obtained by various methods such as pressing with moulds, rollers or belts on which ? reproduced the structure to be imprinted. The process can take place by pressure on not totally hardened resins, on thermoplastic materials, on photo-crosslinkable resins with simultaneous irradiation and photopolymerization.

Always with the aim of faithfully reproducing natural materials, a desired feature? that of having the embossed structure in register with the? printed image or to obtain correspondence between concavity?/convexity? and the printed image. With traditional processes, register embossing (better known by the English acronym EIR: Embossing In Registration) is not possible. simple to obtain, both for the necessary precisions, both for the necessity? to have multiple molds corresponding to the various structures to be printed with the corresponding image.

even more with digital printing making it possible to easily produce different images, a method to obtain the surface structure in a simple and efficient way would be desirable.

In fact, the modern scanners used to acquire the image of materials, for example METIS DRS 2000, also allow the simultaneous acquisition of the surface structure which can be advantageously used for register embossing.

In the past, various technologies have been proposed which provide for the decoration and the formation of surface structures using direct printing on the material to be decorated using inkjet technology:

The EP2108524B1 and EP2507063 patents provide for the use of a UV formulation to generate the 3D structure to generate three-dimensional structures in order to imitate the wood grain.

The EP3109056 patent involves the use of a UV formulation applied by inkjet printing on an uncured UV varnish to generate three-dimensional structures in order to mimic the grain of wood.

The patent WO2020039361A1 provides for direct printing and the creation of three-dimensional structures, in order to imitate the wood grain, by the removal of material.

While the technologies described above provide three-dimensional decoration and structure by means of digital technology, they cannot be used for printing a finished floor plank and cannot be used for decorating three-dimensional (3D) profiles, with contiguous planes.

? therefore it is desirable to identify new methods of decoration and embossing of the surfaces of objects, which are quick, simple and applicable in register on surfaces of different materials, as well as? with low costs.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with one aspect of the invention, the Applicant has found a method for decorating a material by means of digital printing technology.

The present invention is particularly suitable for decorating three-dimensional profiles which can hardly be printed directly. Such profiles are for example skirting boards, door profiles and window profiles.

In the case of digital decoration, the 3D profiles are generally decorated by applying on the surface a plastic or paper film printed by ink jet printing which is subsequently finished with a varnish suitable for protecting the print. The application is normally carried out with the use of a glue, generally of the hotmelt type. The high thickness of the film requires a high adhesive weight (60-90 g/m2) which then makes it difficult to trim the film after application.

If the sticker were printed by ink jet printing, the quantity could be reduced, applying it in a differential manner with quantities greater where the mechanical stress ? more high as for example on the radius of the profile.

The process and the transferable decoration object of the present invention reduces the total thickness of the various layers to be transferred, decreasing the adhesive weight required for application.

Advantageously, the reduction in the total thickness of the decorative package makes the decoration more natural and less plastic.

A further requirement of the market regards the possibility? to print ready-to-use panels. Most floors have a mechanical joint (locking, click) for coupling them during installation. Said profile ? present on all 4 sides and is generally produced using profiling machines after the decoration and cutting of the panels. During profiling, a chamfer (bevel) is normally generated which must then be colored to make it homogeneous with the color of the floor.

Another problem for the decoration of finished floors? the application of the protective varnish which, being applied at high weights, typically 80-250 g/m<2 >, tends to dirty the bevel, the joint system and create the typical creasing effect near the? edges due to the abundance of paint.

It would therefore be desirable to find a solution capable of decorating a finished floor plank while avoiding the aforementioned problems.

DETAILED DESCRIPTION OF THE INVENTION

The method object of the invention foresees the use of a transferable decoration composed of the following phases:

to. Making a three-dimensional layer by inkjet printing on at least part of a support.

b. Apply one or more of the following layers on at least part of the support:

the. Release layer

ii. Protective layer

iii. Decorative layer

iv. White layer

v. Colored layer

you. Adhesive layer

c. Apply the transferable decoration on at least one part of a material to be decorated.

d. Remove the media.

In a preferred embodiment of the invention, the method object of the invention provides for the use of a flexible support as a means for transferring the layers applied to it onto the material to be decorated.

In a preferred embodiment of the invention the support ? flexible and can be made of synthetic polymers such as BOPP, PP, PET, PE, PVC; natural polymers such as cellulose, paper and combinations thereof. In order to keep costs down, the flexible media is between 12? and 100?. Lower thicknesses are more? complex to manage in the machine, especially at high speeds, while higher thicknesses could be inconvenient, especially if the film is used only once. Obviously nobody forbids that different thicknesses can be used to meet specific needs.

In one aspect of the invention the flexible support is used only once and after having transferred the desired layers, it is rewound and destined for raw material recycling. In this case the three-dimensional structure remains integral with the flexible support.

In another aspect of the invention the flexible support is used continuously. All layers, including the three-dimensional one, are transferred onto the material to be decorated. In this way the flexible support can? be reused to repeat the operation indefinitely. For this application, the flexible support ? preferably made of a mechanically resistant material consisting of but not limited to a rubber such as silicone rubber, FKM, EPDM, with a thickness between 0.5mm and 5mm.

In another form of the invention, the support ? rigid and is used as if it were a mold which transfers the decoration by pressing it onto the material to be decorated.

In order to obtain different glosses, the flexible support can in turn have a defined gloss that will? then repeated from the first layer applied to the flexible support. For example, if the flexible support had a gloss of 8(60?) and the first layer was the protective varnish, once transferred this would have a gloss of 8(60?).

In principle, all the layers that make up the transfer can be applied by inkjet printing.

Inkjet printing can be both in mode? multipass/scanning where the image is generated with multiple passes of the head while the material to be printed advances or in mode? singlepass, where the material to be printed passes only once under the heads that are installed at the width of the same material. Single pass printing? used for large runs (>1000 m2/h) while the multipass one, used for small and medium runs (10-600 m2/h), is surely the most common.

Inkjet printing typically involves the use of a head to create and throw droplets of liquid which will then form the image to be printed. As an example details of this type of printing can be found in the book ?Fundamentals of inkjet printing: the science of inkjet and droplets? (Hoath, Stephen).

Depending on the inkjet head used, the droplets produced can have different volumes and consequently different diameters

In addition to the native size of the drop, an intrinsic characteristic of the head, larger drops can be generated by the head itself. For example, a head capable of throwing 4 levels of gray, will have? the drop pi? small of 6 pl while the pi? great will be of 18 pl.

Alternatively, traditional film application technologies such as gravure, flexography, roller and curtain coaters can be used.

In a preferred aspect of the invention, the use of slot-die which allows to easily dose the quantity is particularly suitable. applied and to modulate the application width through the use of inserts.

The three-dimensional layer is preferably generated by ink jet printing with the advantage of easily obtaining registration with the underlying image. Like a mold or cylinder, the three-dimensional layer will produce in the protective varnish its negative.

In the event that the three-dimensional layer is transferred together with the other layers, in order to obtain the three-dimensional structure created in the protective varnish, the three-dimensional layer will go? removed. The three-dimensional layer? formulated in order to obtain a material more? tender / fragile of the protective varnish in which the three-dimensionality? will be incorporated. In general, the Tg of the three-dimensional layer will have to? be lower than the Tg of the protective varnish, facilitating its removal.

Preferably the removal of the three-dimensional layer will be? mechanical type and pu? therefore be carried out with the same machinery used for the rustication/brushing of the wood. These machines use brushes and / or pads made of materials more? or less aggressive (steel, brass, nylon fibres, polyester fibres) according to the hardness of the material to be removed and the degree of finish desired. material to be removed and the desired degree of finish. The equipment described above is, for example, produced by CEFLA (e.g. RSP4) and QUICKWOOD (e.g. CDI/300 LEV).

The removal of the three-dimensional layer can? can also be carried out by means of a jet of air with high pressure or by a jet of water with high pressure.

In a further form of the invention the three-dimensional layer can be removed with the use of a roller or adhesive tape that can? then be cleaned and reused again.

In a further form of the invention the three-dimensional layer can be removed using a suitable solvent.

The depth? of three-dimensionality? created in the protective paint? function of the thickness of the three-dimensional layer and of the layer applied subsequently to the three-dimensional layer.

The protective layer? applied (typically 20-200 g/m<2>) over the three-dimensional layer, its function? to create the three-dimensionality? and protect the press that will come? subsequently applied on the three-dimensional paint layer. The protective varnish can contain anti-abrasive materials to increase abrasion resistance. The abrasion resistance? function of the chemical composition of the paint itself, the presence of anti-abrasive particles, such as aluminum oxide and the thickness applied.

The decorative layer? preferably applied by inkjet printing and generates the decorative image but could also form a plain colour.

The white layer? used to uniform the color of the base and to bring out the decorative layer. The quantity? of white base generally varies between 10 g/m<2 > and 50 g/m<2>, depending on the background color of the material to be decorated and the desired white point.

In another form of the invention, the white base could be made by applying a white film on the material to be decorated. This operation ? commonly used for SPC, onto which a white PVC film is laminated.

The colored layer can be applied in place of the white layer in order to reduce ink consumption and homogenize the background. The color can be applied already? formulated or can? be created online by combining different colors. For example, ? is it possible to overlap more? colored layers to generate the desired tint.

In a further form of the invention, the colored layer is subsequently applied to the white layer with the aim of making a deep incision due to wear less evident. In this case, to increase the resistance to abrasion, the colored layer can contain anti-abrasive fillers

The adhesive layer can be of various nature, such as, but not limited to, hot-melt, heat-activated, PSA and combinations thereof. Preferably the?adhesive ? made of a PSA (pressure sensitive adhesive) with the advantage of obtaining immediate adhesion on the material to be decorated, without using heat and high pressures which could generate mechanical/thermal stress on the previous layers causing damage/breakage.

In a further aspect of the invention, the PSA ? type dual-cure, for example, the curing of the PSA can? take place by means of UV radiation and at the same time you can? activate a secondary reaction between isocyanate and hydroxyl. This type of reaction could be favored by heat.

In a preferred aspect of the invention, the PSA ? applied by inkjet printing.

In another aspect of the invention, the adhesive layer is applied by generating a three-dimensional pattern designed to let the air out during the application of the transfer and therefore minimizing the formation of air bubbles.

In a further aspect of the invention, the adhesive layer is applied in quantity? different in the latitudinal and/or longitudinal direction of printing, by applying greater quantities? where necessary.

In a further aspect of the invention, some layers can be applied by direct application on the material to be decorated. In particular, can be advantageous to apply the white layer with traditional methods as you can? obtain good coverage and given the reduced weight there is no risk of dirtying the bevel and/or the locking.

In a preferred aspect of the invention the adhesive layer is applied directly to the material to be decorated. In this way the transfer will adhere? only on the parts of the material to be decorated where ? been applied the adhesive layer avoiding that it is transferred on parts of the material where the transfer is not ? wanted.

In a preferred embodiment of the invention the adhesive state is applied both on the material to be decorated and on the transfer. In this way you will get greater ease? of adhesion between the 2 layers to be coupled.

In a further form of the invention one or more? of the layers to be transferred also possess properties? stickers. For example, the blank layer and/or the patterned layer may be formulated to be PSAs rather than heat activatable formulations.

In another form of the invention, the layers can react with each other. For example, one layer may contain isocyanate groups and the next and/or previous layer may contain hydroxyl groups forming an isocyanate-type bond between the 2 layers.

In a further aspect of the invention, before applying the three-dimensional layer, a release layer is applied. This layer has the function of facilitating the detachment of the transfer, leaving the support material clean, ready to receive the next layer.

In principle, all the layers that make up the transfer can be applied by inkjet printing.

Alternatively, traditional film application technologies such as rotogravure, flexography, roller and curtain coating machines can be used.

In a preferred aspect of the invention, the use of slot-die which allows to easily dose the quantity is particularly suitable. applied and to modulate the application width through the use of inserts.

Typically, the layers may be of various chemical nature such as, but not limited to, a polyurethane, epoxy, acrylate, acrylic system and combinations thereof.

Preferably the layers consist of 100% solids in order to avoid the operations of evaporation of solvent and/or water.

In a preferred embodiment of the invention the layers are of a photo-crosslinkable nature, a technology amply described in the text ?Radiation Curing: Science and Technology? (Pappas).

Photocrosslinkable resins have in common the fact that they polymerize and harden thanks to the energy radiated by ultraviolet rays devices and/or by irradiation with EB (Electron Beam) and are divided into two types on the basis of the crosslinking mechanism:

1) radicals, typically from vinyl monomers and acrylate resins which are divided into several sub-categories: epoxy acrylate, urethane acrylate, polyester acrylate, polyether acrylate, amino acrylate, silicone acrylate, polyisopren acrylate, polybutadien acrylate and acrylate monomers. Among the vinyl monomers we can mention N-vinyl caprolactam (NVC), acryloyl morpholine (ACMO), diethylene glycol divinyl ether (DVE-2), triethylene glycol divinyl ether (DVE-3) and mixtures thereof.

The term acrylate refers to both acrylate and methacrylate resins.

2) cationic resins such as epoxies, polyols and monomers such as oxetanes and vinyl ethers.

Typically, UV light curing can be carried out with one or more? Hg lamps and/or with LED lamps.

In a preferred embodiment of the invention, for carrying out the method of the invention, LED lamps are used, characterized by lower consumption, longer life and lower heat emission compared to traditional Hg lamps.

The application of the transfer can? take place continuously using for example calenders, double belt presses, rolling lines or discontinuously using for example flat presses and membrane presses.

In the case of profiles, the covering machines normally used for the covering of profiles (Barberan/Cefla) can be used.

In a preferred embodiment of the invention, after the three-dimensional layer has been removed, a finishing varnish is applied to the surface of the protective varnish in order to obtain the desired aesthetics in terms of gloss, touch, scratch resistance and chemical resistance.

In a preferred form of the invention the transfer has a slightly larger size? wide of the material to decorate. This abundance facilitates centering and application. The excess is easily removed with the same machine simultaneously with the removal of the three-dimensional layer incorporated in the protective varnish.

In another form of the invention, the transfer ? consisting of only a few layers. For example, only the protective varnish could be transferred with or without a three-dimensional layer. Or the decorative layer alone could be transferred, without the protective varnish which could then be applied later.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGURE 1

Figure 1A illustrates the structure of the transferable decoration object of the invention.

Figure 1B illustrates the transferable decoration object of the invention applied to the material to be decorated.

Figure 1C illustrates the removal of the flexible support with the 3D layer integral with the support itself.

Figure 1D illustrates the removal of the flexible support only while the 3D layer remains embedded in the protective layer

FIGURE 2

Figure 2 illustrates the process for making and applying the transfer with the flexible support that is continuously reused.

FIGURE 3

Figure 3 illustrates the process for making and applying the transfer with the disposable flexible support and with the 3D structure integral with it.

FIGURE 4

Figure 4 illustrates the decoration of a floor plank with the locking system. The adhesive? applied on the plank surface and on the bevel. Does the transfer adhere where? present the sticker.

FIGURE 5

Figure 5 illustrates the top view of a pattern functional to the release of the air during the application of the transfer:

- 5A pyramid pattern.

- 5B hemispherical/conical pattern.

FIGURE 6

Figure 6 illustrates the three-dimensional layer representing the structure of a brushed wood.

EXAMPLES

EXAMPLE 1

Using continuous flexible media.

- A silicone membrane, thickness 330x1200x3mm ? Was a three-dimensional layer with a thickness of 140 applied? (figure 6) representing the structure of a brushed wood. The three-dimensional layer? was made by printing? ink jet mode? singlepass with a photo-curable formulation designed to allow detachment from the silicone membrane. Structure ? been cured using a 395nm LED UV lamp.

- Subsequently, by slot-die, ? was applied the protective layer, 200?, consisting of a photo-crosslinkable varnish containing aluminum oxide to increase its properties? anti-abrasive. The protective layer? It was then polymerized using a 395nm LED UV lamp. - Subsequently ? Has the image of the wood corresponding to its structure been printed using ink jet printing? single pass. The decorative layer? It was then polymerized using a 395nm LED UV lamp. - On the surface and on the bevel of an SPC (Stone Plastic Composite) plank ? a white layer consisting of a photo-curable formulation was applied. The application ? carried out using a rolling machine in 2 passes of 20 g/m<2 > each. The white layer? It was then polymerized using a 395nm LED UV lamp.

- On the surface where? was the white layer applied? the adhesive layer was applied by means of singlepass type inkjet printing, 25 g/m<2>, consisting of a photo-crosslinkable PSA formulation which ? was then polymerized, using a 395nm LED UV lamp, leaving the adhesive and receptive surface.

- The silicone membrane? was then turned and the transfer applied by means of a calender on the surface of the adhesive SPC surface. The silicone membrane? been pressed on the surface of the SPC making it adhere well to the surface and on the bevel.

- The silicone membrane? was then removed leaving it clean with the transfer applied perfectly to the surface of the SPC dashboard. The three-dimensional layer? visible and incorporated in the protective paint.

- Subsequently by brushing with wire brushes ? The 3D layer has been removed generating its negative inside the protective layer. Simultaneously with the use of TINEX brushes, less aggressive than those previously used, ? been removed? Abundance of the transfer which is facilitated by the fact that it is not? adhesive.

- Finally ? a finishing layer consisting of a photo-crosslinkable formulation for floors with gloss 8, polymerised with a Hg lamp, was applied by roller painting.

Structure ? well defined, with depth? maximum of 140?. Abrasion according to EN13229 corresponds to AC5.

EXAMPLE 2

Use of a disposable flexible support.

- BOPP film, dimensions 14000x80x0,05mm ? was a three-dimensional layer with a thickness of 80 applied? (figure 6) representing the structure of a brushed wood. The three-dimensional layer? was made by printing? ink jet mode? singlepass with a photo-curable formulation designed to ensure adhesion on the flexible support. Structure ? been cured using a 395nm LED UV lamp.

- Later by slot-die ? was applied the protective layer, 100?, consisting of a photo-crosslinkable varnish containing aluminum oxide to increase its properties? anti-abrasive. The protective layer? It was then polymerized using a 395nm LED UV lamp. - Subsequently ? Has the image of the wood corresponding to its structure been printed using ink jet printing? single pass. The decorative layer? It was then polymerized using a 395nm LED UV lamp. - Subsequently ? was applied, 25 g/m<2 >by means of singlepass type ink jet printing, the adhesive layer consisting of a photo-curable PSA which is It was then polymerized using a 395nm LED UV lamp.

- Flexible support ? was then rewound.

- After the transfer? was applied, using a BARBERAN resurfacing machine, to a white PVC skirting board profile.

- After the application, the flexible support? been removed leaving the transfer perfectly adhered to the profile.

- The surface of the profile appears decorated with a three-dimensional protective varnish representing a brushed wood grain.

Structure ? well defined, with depth? maximum of 80?.

Claims (15)

1. A process for making a transferable decoration comprising the steps of: to. Create a three-dimensional structure on at least one part of a support. b. Create a transferable decoration by applying one or more? of the following layers on at least part of the support on which ? the three-dimensional structure was created: the. Release layer ii. Protective layer iii. Decorative layer iv. White layer v. Colored layer you. Adhesive layer c. Apply the transferable decoration on at least one part of a material to be decorated. d. Remove the media. 2. Method according to claim 1 in which the layers consist of photocrosslinkable systems. 3. Method according to the preceding claims in which the adhesive is applied with different weights in the latitudinal and/or longitudinal direction with respect to the material to be decorated. 4. Method according to the preceding claims in which the adhesive is applied with a pattern adapted to facilitate the release of the air during application. 5. Method according to the preceding claims in which one or more? layers in addition to their main feature (release / protective / decorative / white / colored) behave like an adhesive. 6. Method according to the preceding claims in which the adhesive is a PSA (Pressure Sensitive Adhesive). 7. Method according to the preceding claims in which the colored layer is generated by applying 2 or more? overlapping colors. 8. Method according to the preceding claims wherein between 2 or more? layers in contact with each other, a chemical reaction occurs. 9. Method according to the preceding claims in which one or more? layers are applied on the material to be decorated before applying the transferable decoration. 10. Method according to the preceding claims in which the transferable decoration is applied simultaneously on several? contiguous planes of the material to be decorated. 11. Method according to the preceding claims in which after the application of the transfer on the surface to be decorated, the three-dimensional structure remains incorporated in the protective varnish. 12. Method according to the preceding claims in which the three-dimensional structure is removed from the protective varnish, leaving the negative thereof inside the protective varnish. 13. Method according to the preceding claims wherein at least 1 of the layers is applied by ink jet printing. 14. Method according to the preceding claims wherein the substrate to be decorated is a floor plank finished with the locking system and/or bevel, but not decorated. 15. Method according to the preceding claims wherein the support is chosen from synthetic polymers, natural polymers, paper and their combinations.