MECHANICAL REFLECTION AND IRRADIATION SYSTEM FOR CROSS-LINKING UV POLYMERIZABLE PAINTS

Abstract

A mechanical reflection and irradiation system applicable to common ovens for cross-linking, induced by Excimer lamps, of UV-curable paints applied to three-dimensional elements, such as door parts, doors, panels, windows etc., with cubic elements, parallelepipeds and other solids of rotation and in any case of elements in general characterized by combinations of flat and vertical surfaces to obtain ultra-matt surfaces.

Claims

1. Mechanical system for reflection and irradiation applicable to ovens for cross-linking UV-curable paints applied to a three-dimensional element or support, said mechanical system comprising a system for transporting and moving said three-dimensional element through: a painting area, a pre-gelling zone (step 3), a surface polymerization zone (phase 4), and a final polymerization zone (phase 5), in which at least the surface polymerization zone is provided with: a lower reflecting element; an upper reflective element; at least one Excimer lamp; one or more translation guides for moving the three-dimensional element, said translation guides being such as to space the three-dimensional element by a distance with respect to the lower reflecting element.

2. Mechanical system according to claim 1, wherein the surface polymerization zone is further provided with two lateral reflecting elements.

3. Mechanical system according to claim 2, wherein at least one area of the pre-gelling and final polymerization zones is provided with: a lower reflective element; an upper reflective element; at least one light source; one or more translation guides for moving the three-dimensional element, said translation guides being such as to space the three-dimensional element by a distance with respect to the lower reflecting element.

4. Mechanical system according to claim 3, wherein two lateral reflecting elements are associated with the lower reflecting element and the upper reflecting element.

5. Mechanical system according to claim 3, wherein the light source is chosen from: LED lamps capable of emitting a radiation with a wavelength between 365 and 405 nm, preferably 395 nm, and with a power of between 2 and 20 W/cm, preferably 8 Watt/cm; low power arc UV lamps such as gallium, mercury or iron lamps with a power between 10 and 50 W/cm or other UV lamps; UV lamps capable of producing monochromatic wavelengths in the UV-C region (200-300 nm); Gallium UV lamps or UV-LED lamps capable of emitting radiation with a wavelength between 300 and 420 nm, preferably 395 nm, and with a power of between 2 and 20 Watt/cm, preferably 8 W/cm; mercury lamps with variable powers between 80 and 200 W/cm; and related combinations.

6. Mechanical system according to claim 1, in which Excimer lamps are used, capable of emitting a radiation with a wavelength preferably of 172 nm and a power of between 0.5 and 50 Watt/cm, with water or air cooling and in an inert nitrogen atmosphere with oxygen levels between 1 and 1,000 ppm.

7. Mechanical system according to claim 1, which is realized as: a single device where the pre-gelling steps (step 3), Excimer surface polymerization (step 4), final polymerization (step 5) are carried out continuously.

8. Mechanical system according to claim 1, wherein the Excimer lamp is arranged above the support perpendicularly with respect to the transport direction or with an inclination up to 60°.

9. Mechanical system according to claim 3, wherein each of the light sources and is independently arranged above the support perpendicularly with respect to the transport direction or with an inclination up to 60°.

10. Mechanical system according to claim 3, wherein the lower, upper and lateral reflecting elements are chosen from: mirror-polished AISI 316 stainless steel mirrors or aluminum.

11. Mechanical system according to claim 3, wherein the length of each of the light sources and of the Excimer lamp independently covers all the width of the support and protrudes on both sides for a distance of at least 10%, up to 100%, with respect to the width of the support itself

12. Mechanical system according to claim 2, wherein the lateral reflecting surfaces are provided with systems for adjusting the inclination with respect to the plane or for adjusting the distance to the support.

13. Mechanical system according to claim 3, wherein the support is located at a distance from the light sources and from the Excimer lamp, said distance being adjustable independently for each of said lamps and light sources.

14. Mechanical system according to claim 3 wherein the support is raised up to a distance greater than 0.1 mm, preferably between 0.1 mm and 5 cm, more preferably between 0.1 mm and 2 cm, with respect to the lower reflecting element, to allow a UV uniform reflected radiation.

15. Method for the realization of ultra-matt coated surfaces obtained by using UV cross-linkable coating products, characterized in that it is carried out in the mechanical system according to claim 1, and comprising the following steps: application of the UV cross-linkable coating product with a thickness from 30 to 300 λm, possible evaporation of solvents and/or coalescents or water, pre-gelling, polymerization of the surface layer of the coating film, induced by Excimer lamps, final polymerization of the coating film.

16. Three-dimensional coated products obtained with the device according to claim 1, wherein all surface zones of the product have the same resistance to the squaring test carried out according to the UNI EN ISO 2409:2013 standard.

Description

[0035] Further characteristics and advantages of the invention will be clearer from the description of a preferred but not exclusive embodiment of the mechanical system of the present patent application, illustrated by way of and indicative but non-limiting example in the appended drawings below:

[0036] FIG. 1 shows in axonometric view a mechanical system (1) designed to extend the irradiation of Excimer UV radiation to the shaded areas of a coated three-dimensional element or support (2), wherein said mechanical system (1) is composed of: [0037] a lower reflecting element (3a); [0038] an upper reflecting element (3b); [0039] two lateral reflecting elements (4a, 4b); [0040] at least one LED lamp (5a); [0041] at least one Excimer lamp (5b); [0042] at least one UV lamp (5c); [0043] two translation guides (6a, 6b) for moving the three-dimensional element (2);

[0044] FIG. 2 shows in a lateral view the mechanical device (1) in FIG. 1. wherein: [0045] (A) represents the angle of inclination of the lateral reflecting elements (4a, 4b); [0046] (C) represents the adjustment distance of the lateral reflecting elements (4a, 4b); [0047] (D) represents the adjustment distance of the LED lamp (5a), of the Excimer lamp (5b) and of the UV lamp (5c) with respect to the coated support (2);

[0048] FIG. 3 shows in a view from above the mechanical system (1) in FIG. 1. wherein: [0049] (B) represents the angle of inclination of the Excimer lamp (5b); [0050] (E) represents the adjustment angle of the UV lamp (5c).

[0051] FIG. 4 shows in an axonometric view the translation guides (6a, 6b) and the transport and moving system of the (not shown) three-dimensional element (2) made of one or more chain elements (7a, 7b, 7c) to be associated with the mechanical system (1) of FIGS. 1-3;

[0052] FIG. 5 shows in a front perspective view what was described in FIG. 4.

[0053] These and other purposes are achieved with the present invention which relates to a mechanical reflection and irradiation system applicable to standard Excimer lamp-induced cross-linking ovens of UV polymerizable coatings applied to three-dimensional elements, such as furniture doors, doors, panels, windows etc., to cubic elements, parallelepipeds and other rotation solids and in any case to elements generally characterized by combinations of flat and vertical surfaces to obtain ultra-matt surfaces.

DETAILED DESCRIPTION OF THE INVENTION

[0054] According to the present invention, the terms “ultra-matt paint” and “low-gloss” coated surfaces are meant to refer to surfaces which reflect light with a brightness degree lower than 5 Gloss Unity GU, measured with a geometry at 60° according to the UNI EN ISO 2813/2016 standard.

[0055] According to a preferred—but not limiting—embodiment, the present invention relates to a mechanical system (1) of reflection and irradiation applicable to normal cross-linking ovens, induced by Excimer lamps of UV polymerizable paints applied to a three-dimensional element or support (2), such as for example furniture doors, doors, panels, windows etc., to cubic elements, parallelepipeds and other rotation solids and in any case to elements generally characterized by combinations of flat inclined vertical surfaces for obtaining ultra-matt surfaces. According to the invention, following elements are also comprised: [0056] the flat surfaces, [0057] the curved surfaces, where curved refers to convexity and concavity, [0058] the profiles of said flat and curved surfaces,
all surfaces being disposed vertically, horizontally and inclined in the space.

[0059] Said mechanical system (1) consists of: [0060] a lower reflecting element (3a); [0061] an upper reflecting element (3b); [0062] two possible lateral reflecting elements (4a, 4b); [0063] at least one possible LED lamp (5a); [0064] at least one Excimer lamp (5b); [0065] at least one possible UV lamp (5c); [0066] one or more, for example two translation guides (6a, 6b) for moving the three-dimensional element (2).

[0067] Said mechanical system (1) can be applied either to the only cross-linking surface area [step(4)] as explained below, or also independently to each of the pre-gelling steps [step(3)] with the aid of the LED lamp (5a) and the final polymerization [step(5)] with the aid of the UV lamp (5c).

[0068] The production of ultra-matt painted surfaces with low light reflection (low “gloss”) and high physical chemical performance by using UV cross-linkable coating products takes place by means of a process consisting of the following steps: [0069] 1) application of the UV cross-linkable coating product, [0070] 2) possible evaporation of solvents and/or coalescents or water on a “flash off” plant, [0071] 3) pre-gelling, [0072] 4) polymerization (cross-linking) of the surface layer of the coating film, induced by Excimer lamps (5b), [0073] 5) final polymerization (cross-linking) of the coating film.

[0074] Ultra-matt surfaces with low “gloss” on three-dimensional elements (2) (flat and vertical surfaces such as edges of products such as furniture doors, doors, panels, windows, etc.) are obtained by combining the use of UV coating products with a mechanical reflection and irradiation system (1) of the radiation produced by Excimer lamps of this patent application. In detail, the steps of the process indicated above, which allow ultra-matt surfaces with low “gloss” to be obtained and which can be applied not only to flat surfaces, but also and above all to three-dimensional products thanks to the system (1) of this patent application, are described below. [0075] 1) The application of the coating products is carried out using the coating systems known in the state of the art, in particular the manual and/or mechanised spray coating system using paint robots. The coating film applied may have a thickness ranging from 30 to 300 microns. [0076] 2) The evaporation of solvents and/or coalescents and/or water, present in the formulation of the coating products, can be achieved by means of a “flash off”/evaporation system known in the state of the art, which uses a laminar air flow in combination with heating systems consisting of IR lamps, or any other instrument, combined with low intensity UV lamps (TI lamps). [0077] 3) The pre-gelling process of the coating products must be applied to coating films of a thickness of more than 10 microns on flat surfaces and edges of three-dimensional elements and consists of achieving a pre-polymerization of the inner layer of the film, while the outer surface layer remains in the liquid state for a thickness of about 10 microns. The pre-gelling process is induced and controlled using UV radiation sources such as low power UV lamps (EP2794126B1), LED lamps (5a), UV-C lamps. Depending on the emission profile and power of the UV radiation chosen for the pre-gelling process, the thickness of non-pre-gelled liquid paint that remains on the outer surface of the coating film influences and determines some characteristics of the finished product, such as the three-dimensional effects of the “soft touch” type (extreme softness to the touch induced by a micro-roughness of the surface layer) and/or surface texturing, as well as determining the intensity of the “gloss” and the chemical-physical characteristics of resistance to scratching, abrasion and chemical agents of the coating film and the intensity of its adhesion to the coated surface. In addition, the pre-gelling process makes it possible to obtain the textured effects and characteristics previously described also on more regular geometric structures such as hemispheres or regular three-dimensional “patterns” (DE102016120878A1). [0078] 4) The surface polymerization/cross-linking process of the coating products applied to flat surfaces and edges of three-dimensional elements is induced by Excimer lamps (5b) with air or water-cooled UV radiation of 172 nm and power between 0.5 and 50 W/cm. The polymerization/cross-linking process takes place in an inert nitrogen atmosphere with oxygen levels between 1 and 1.000 ppm. [0079] 5) The final polymerization/cross-linking process of coating products applied to flat surfaces and edges of three-dimensional elements involves the use of one or more Gallium UV lamps (5c) in combination with one or more Mercury lamps with powers between 80 and 250 W/cm, or alternatively with UV LED lamps, with radiation emission at wavelengths between 300 and 420 nm, and powers between 2 and 20 W/cm.

[0080] The object of this patent application consists of a mechanical reflection and irradiation system (1) of UV radiation applicable to standard Excimer lamp cross-linking ovens and such as to allow the irradiation to be extended also to points of the three-dimensional element not directly exposed to the lamp (shaded areas), in combination with coating products to be applied on flat surfaces and edges of three-dimensional elements to achieve the polymerization/cross-linking of the coating film without having to resort to the “edge banding” technique and obtain surfaces with low “gloss” and high performance characteristics in terms of resistance to scratches, abrasion, chemical agents. Said innovative mechanical system (1), non-existent in the state of the art, is advantageously used in the pre-gelling, polymerization/surface cross-linking steps induced by Excimer lamps (5b) and final polymerization/cross-linking of the coating film.

[0081] The mechanical system (1) can be conceived either as a single apparatus where the three pre-gelling steps (step 3), Excimer surface polymerization/cross-linking (step 4), final polymerization/cross-linking (step 5) occur continuously (FIGS. 1-3), or as an apparatus consisting of three separate sections in which the three pre-gelling steps (step 3), Excimer surface polymerization/cross-linking (step 4), final polymerization/cross-linking (step 5) can be conducted separately in a discontinuous manner.

[0082] In the case of three separate sections (embodiment non shown), the section relating to step 4 will comprise the following elements: [0083] a lower reflecting element (3a); [0084] an upper reflecting element (3b); [0085] two possible lateral reflecting elements (4a, 4b); [0086] at least one Excimer lamp (5b); [0087] one or more, for example two translation guides (6a, 6b) for moving the three-dimensional element (2).

[0088] Each further section, applicable independently to step 3 and step 5 will comprise lower (3′a) and upper (3′b) reflecting elements; possible lateral reflecting elements (4′a, 4′b); light sources (5a) and (5c) chosen as a function of the step; one or more translation guides, for example (6′a, 6′b), for moving the three-dimensional element (2),

[0089] For the pre-gelling step (step 3) the mechanical system (1) uses one or more radiation sources UV (5a) capable of emitting a radiation at a wavelength between 365 and 405 nm, preferably 395 nm, and having a power between 2 and 20 W/cm, preferably 8 Watt/cm. The radiation source (5a) is arranged above the coated support (2) perpendicular to the direction of transport or with an inclination of up to 60° (not shown in FIG. 3).

[0090] The radiation sources UV (5a) with the emission characteristics cited above can be chosen from LED lamps, low power UV arc lamps as gallium, mercury or iron lamps, with power from 10 to 50 W/cm or other UV lamps.

[0091] As a UV radiation source (5a) also the use of UV lamps can be considered, which are able to produce mono-chromatic wavelengths within the range UV-C (200-300 nm). Each of the UV radiation sources (5a) mentioned above, even if it emits radiations with different wavelength, is able to produce an adequate cross-linking even if it leaves the outer surface layer of the paint in the liquid state for a thickness of about 10 μm.

[0092] For the Excimer surface polymerization/crosslinking step (step 4) the system uses one or more Excimer lamps (5b) capable of emitting radiation at a wavelength preferably of 172 nm and having a power between 0.5 and 50 Watt/cm, with water or air cooling and inert nitrogen atmosphere with oxygen levels between 1 and 1,000 ppm.

[0093] The UV radiation source (5b), preferably an Excimer lamp or other UV radiation source of similar performances, is arranged above the coated support (2) perpendicular to the direction of transport or with an inclination (B) of up to 60°.

[0094] For the final polymerization/cross-linking step (step 5) the system uses one or more Gallium UV lamps (5c). The Gallium UV lamps (5c) can be chosen between: Gallium UV lamps also in combination with one or more mercury lamps with powers ranging from 80 to 200 W/cm or, alternatively, UV-LED lamps capable of emitting radiation at a wavelength ranging from 300 to 420 nm, preferably 395 nm, and having a power ranging from 2 to 20 Watt/cm, preferably 8 W/cm.

[0095] The lamp (5c) is arranged above the coated support perpendicular to the direction of transport or with an inclination (E) of up to 60°.

[0096] The length of the lamp (5a-5b-5c), covers the entire width of the coated support (2) and protrudes on both sides for a distance (C) of at least 10%, up to 100%, with respect to the width of said support (2).

[0097] At the sides, below and above the coated support (2) lateral reflecting elements (4a, 4b), a lower reflecting element (3a) and an upper reflecting element (3b), for example mirrors, AISI 316 mirror polished stainless steel elements (EN188-2) are respectively arranged, so that the UV radiation of the pre-gelling LED lamps (5a), the Excimer lamps (5b) and that of the final cross-linking (5c) are reflected to radiate not just the surfaces directly exposed to the UV source, but also the surfaces not directly exposed (shaded areas). In order to obtain ultra-matt surfaces both on the plain surfaces and on the variably curved surfaces and also on the edges of a three-dimensional element according to the present invention: [0098] in the pre-gelling step (step 3) and the final polymerization/cross-linking step (step 5) , the lateral reflecting elements (4a, 4b), the lower reflecting element (3a) and the upper reflecting element (3b), are optional; [0099] the lateral reflecting elements (4a, 4b) are optional in the surface polymerization/cross-linking step, also called Excimer step (step 4), as it can be obtained with lamps having performances similar to those of the Excimer lamps; [0100] the lower (3a) and upper (3b) reflecting elements are most important in the surface polymerization/cross-linking step, also called Excimer step (step 4) as previously indicated.

[0101] It has been found out that, even if the lateral reflecting elements (4a, 4b) are optional in all steps, it is possible to obtain ultra-matt surfaces also on the edges of the three-dimensional element, as the reflexion mechanism from the reflexion surface is not a direct reflexion mechanism but a diffused reflexion mechanism.

[0102] This is possible as a feature of the radiation typology emitted from an Excimer lamp is that, when it meets a reflecting surface, it is subjected to a diffused and not direct radiation. Therefore a precise reflexion angle does not exhist and the diffusion component of the reflecting surface is predominant with respect to the direct one.

[0103] The lateral reflective surfaces (4a, 4b) are equipped with systems for adjusting (not shown) the inclination (A) with respect to the plane or for adjusting the distance (not shown in FIG. 2) with respect to the support (2).

[0104] The transport and handling system is designed so that the support (2) is lifted with respect to the lower reflecting element (3a) up to a distance (H), preferably of 0.1 mm or more, more preferably from 0.1 mm to 5 cm; particularly preferred is the range from 0.1 mm to 2 cm, so as to allow a uniform UV reflected radiation.

[0105] The adjustment distance (D) from the coated support (2) of the LED lamp (5a), of the Excimer lamp (5b) and of the UV lamp (5c) to the Gallium can be adjusted independently for each of them.

[0106] The mechanisms for adjusting the inclination of the reflective lateral elements (4a, 4b) and of the height of the UV radiation sources for the pre-gelling element (5a), Excimer (5b) and final cross-linking (5c) may entail the use of: [0107] linear motors, brushless motors both stepper and drive; [0108] recirculating ball screws for height adjustment through the drive of the motor which, via a transmission shaft system, moves said screws synchronously.

[0109] Pneumatic systems can also be used to simplify the realization of the mechanical system according to the invention.

[0110] It is also possible to use levers to manage the adjustments of the adjustable movable elements such as mirrors and their inclination and distance, the height of the various lamps.

[0111] Measurement guides (not shown) or other suitable instruments may be installed to assess the various angles and the positioning of all the reflective elements (3, 4a, 4b).

[0112] All the adjustments can be equipped with control systems (not shown) to detect the actual position of the heights and perform positioning with electronic control systems.

[0113] The transport system can be made in a single element for all three steps of the process (pre-gelling, surface polymerization/cross-linking, final polymerization/cross-linking) or in three separate and distinct elements. It may provide for the use of one or more catenary elements (roller chain), or alternatively one or more transmission chains, alternatively two or more free roller chains, alternatively one or more tracked chains, alternatively one or more conveyor belts with or without raised shims, alternatively slatted conveyor belts.

[0114] The mechanical system (1) of this patent application, used in combination with the coating products, makes it possible to obtain immediately handled, stackable three-dimensional coated elements, characterized by ultra-matt surfaces with low “gloss” (less than 10) and with very high performance characteristics of resistance to scratches, abrasion and chemical agents, self-repair via induced heat for scratches procured with diamond tip and applied force less than 5 N, relative to all surfaces (flat and edges) of the coated three-dimensional element.

[0115] With reference to what described before, tests are shown below which are illustrative and non limiting of the physical-chemical performances of a Excimer lamp UV cross-linking coating product, both on the plane and on the edges of a three-dimensional element with the use of the mechanical system according to the invention.

[0116] The test report LABPCF 10049 makes reference to a painting cycle made on a polyester oak support with dimensions 50×50 cm and thickness 2 cm. The finishing is a specific formulation for a UV polymerization with Excimer lamps based on acrylic resins with a total dry residue of 85% and provides a content of matting silicas very low (<1%) (UVX5818F produced by Industria Chimica Adriatica S.p.A.). The final aesthetic result obtained is a surface very soft to the touch, with a very good opacification and gloss uniformity lower than 5 (60°) and 15(85°).

[0117] Chemical resistance: a comparison is made between plane and edge. The chemical resistances are identical on both surfaces and are very high.

[0118] Scratch resistance: a comparison is made between plane and edge by using the Dur-O-test method with Erichsen pen. The scratch resistances are identical on both surfaces and are very high.

[0119] List of Tested Samples

[0120] The tests were carried out on the edge and on the plane of the same specimen.

TABLE-US-00001 TABLE 1 Tests performed/Test: Squaring Test, Dur-O-Test, Resistance to cold liquids, Internal light resistance, Thickness - Ultrasonic Thickness meter Used supports/Support: Oak Phase Product Additive Catalyst Thinner Quantity Time Comments Manual POLYESTER PLANE spray GROUND Manual 320 sandpapering Manual UVX5818F 2% FI55 C200 5 90 spray Pre-gelling 5′ 35° C. tunnel LED lamp 50% 5 cm 5 m/min LED lamp Excimer 50% 5 m/min UV 2 tunnel p. lamps

Squaring Test (UNI EN ISO 2409: 2013)

[0121] Method:

[0122] On the painted support, six perpendicular incisions are performed with a special cutting tool spaced 1, 2, or 3 mm depending on the thickness of the paint film. In this way, a lattice consisting of 25 squares is created. This is applied with standard adhesive tape and pulled away in a regular motion. The analyzed surface is evaluated.

[0123] Ratings:

[0124] 0=The edges of the incisions are perfectly intact: no small square has come off.

[0125] 1=Small flakes of paint are detached at the intersections of the lines for a surface smaller than 5% of the total area.

[0126] 2=Small flakes of paint are detached at the intersections of the lines for a surface between 5 and 15% of the total area.

[0127] 3=The paint has detached along the edges of the cracks and in part of the squares for 15-35% of the total area.

[0128] 4 =The separation of the squares involves 35 to 65% of the total area.

[0129] 5 =The detachment is almost total or total.

[0130] Usable methods: 1) Single-blade tool; 1a) Manual single blade tool; 1b) Motorized single blade tool; 1c) Cutter with rigid blade with sharp V-shaped edge; 2) Multi-blade tools; 2a) Manual multi-blade tool; 2b) Motorized multi-blade tool

[0131] Referring to table 2 above, zones 1, 2 and 3 are three randomly chosen positions of the same support. The 2 mm spacing indicates the distance between the individual incisions necessary to realize the lattice indicated in the test description.

TABLE-US-00002 TABLE 2 LAB: 62775 Description of specimen Plane SPECIMEN: 1 Zone Spacing Method Evaluation zone 1 2 mm 1c 0 zone 2 2 mm 1c 0 zone 3 2 mm 1c 0 LAB: 62984 Description of specimen UVX5818F Edge SPECIMEN: 1 Zone Spacing Method Evaluation zone 1 2 mm 1c 0 zone 2 2 mm 1c 0 zone 3 2 mm 1c 0

[0132] With reference to above table 2, zones 1, 2 and 3 are three casually chosen positions of the same support. The spacing of 2 mm indicates the distance among the single etchings necessary for realizing the lattice indicated in the test description.

Evaluation of the Resistance of Surfaces to Cold Liquids

UNI EN 12720: 2013

Conditioning

[0133] N° 7 days at 23±2° C. and 50±5% relative humidity

[0134] Method:

[0135] The chemical agents are applied on filter paper placed in contact with the painted surface and covered with watch glass slides. After the time prescribed by the regulations, the surface is cleaned and, after twenty-four hours, the results are evaluated.

[0136] For the sake of completeness, the meaning given by the UNI EN 12720 standard to the numbering is reported:

[0137] 1: Strong change: the tested area is distinguishable in all observation directions. The structure is extremely modified.

[0138] 2: Significant change: the tested area is distinguishable in all directions of observation. Structural changes (formation of bubbles, fiber lifting cracks) occur as well as changes in opacity and color.

[0139] 3: Moderate change: the tested area is distinguishable in many observation directions. There are no changes in structure (formation of bubbles, breakages, lifting of the fiber, etc.) but only changes in opacity and color.

[0140] 4: Slight change: the tested area is distinguishable only in one direction of observation. There are no changes in structure (formation of bubbles, breaks, lifting of the fiber) but only changes in opacity and color.

[0141] 5: No change: the tested area is not distinguishable from the rest of the sample.

TABLE-US-00003 TABLE 3 Code number: LABPCF_10039_001: Support: Oak Gloss: Product Additive Catalyst % cat: POLYESTER GROUND UVX5818F 2% FI55 C200 5 10 2 10 1 6 8 16 24 Chemical agent sec min min hour hours hours hours hours Acetic acid 10% 5 Citric acid 10% 5 Water 5 Etyl alcohol 48% 5 Ammonia 10% 5 Coffee 5 Liquid paraffin 5 Detergent solution 5 Basic sweat 5 Code number: LABPCF_10049_002: Support: Oak Gloss: Product Additive Catalyst % cat: POLYESTER GROUND UVX5818F 2% FI55 C200 5 10 2 10 1 6 8 16 24 Chemical agent sec min min hour hours hours hours hours Acetic acid 10% 5 Citric acid 10% 5 Water 5 Etyl alcohol 48% 5 Ammonia 10% 5 Coffee 5 Liquid paraffin 5 Detergent solution 5 Basic sweat 5

Determination of Light Resistance

UNI EN 15187: 2007

[0142] Method:

[0143] The painted panels are exposed to the radiation produced by a xenon lamp (1.25 Watt/m2 at a wavelength of 420 nm) for a time determined by the variation of the gray scale variation of the standard n. 6 of blue wool. The test is performed at a temperature of 50° C.

[0144] With this test the light resistance of a surface behind glass is simulated. Color change evaluation is done visually through the gray scale with spectro-photometric measurement.

[0145] Tools used: XENON TEST CHAMBER of the company Q-SUN

TABLE-US-00004 TABLE 4 Sample LAB description DL DA DB DE Evaluation 62775 PLANE −0.31 −0.34 −1.49 −1.56 4/5

[0146] Referring to table 4 above, the colour of a surface is measured using a three-axis Cartesian system where: [0147] L represents the light-dark axis [0148] A represents the red-green axis [0149] B represents the yellow-blue axis

[0150] Therefore DL, DA and DB represent the variation for each color axis with respect to the initial reference.

[0151] The measurement is carried out by spectrophotometer and the value 4/5 indicates the variation of the color on the gray scale, or an almost imperceptible variation, using colorimetric references available to the operator.

Spring Hardness (Dur-O-Test)

Hard Surfaces—Internal method

[0152] Method:

[0153] Using a special tool, consisting of a tungsten tip or a diamond point, to which pressure is applied by an adjustable spring, a mark is drawn on the painted surface. The Tungsten tip, when the applied forces range from 2N to 0.3N is used in opaque products to observe how the opacant is superficially lined; applying greater strength the film hardness is examined, understood as resistance to a pressure localized on a small surface. The diamond point, being able to engrave/cut the surface, allows to observe the scratch resistance of the product.

[0154] The tool is equipped with three springs (red and blue silver) at different voltages; [0155] Silver from 0 to 300 g [0156] Red from 0 to 1000 g [0157] Blue from 0 to 2000 g

[0158] The spring is chosen by observing the first that leaves a mark by applying the maximum pressure (eg Silver 300 g). Different marks are made for different forces and each mark is evaluated in a scale from 1 to 5. The etching caused by the tip on the surface is evaluated after 24 h, in the observation booth described in all the regulations on painted surfaces.

[0159] 1: Pronounced mark. The coating film is totally/partially raised or the mark is whitened.

[0160] 2: Pronounced mark. The surface is deeply etched and is easily recognizable by touch.

[0161] The mark is visible from every direction. The lifting of the paint film is not observed.

[0162] 3: Slight mark. Not distinguishable by touch and easily visible from many directions of observation.

[0163] 4: Slight change of brightness only when the light source is reflected in the test surface, on the mark or very close to it and is reflected towards the eye of the observer, or some isolated marks just visible.

[0164] 5: No visible change (no damage).

TABLE-US-00005 TABLE 5 LAB Description of specimen 62775 Plane 20N 15N 10N 6N 5N 4N 3N 2N 1.5N 1N 0.7N 0.5N 0.3N 4 4 4 4 4 4 5 5 5 5 5 5 5 1N 0.7N 0.5N 0.3N 0.1N 4 4 4 5 5 62984 UVX5818F Edge 20N 15N 10N 6N 5N 4N 3N 2N 1.5N 1N 0.7N 0.5N 0.3N 4 4 4 4 4 4 5 5 5 5 5 5 5 1N 0.7N 0.5N 0.3N 0.1N 4 4 4 5 5

[0165] The test was performed by analyzing the scratch generated by the tungsten tip starting from 0.5 mm from the upper edge up to 0.5 mm from the lower edge. From the report of each test it is clear that the performances obtained are identical both on the plane and on the edge of a three-dimensional element. The characterizing element is the high scratch resistance (Dur-O-TEST) for both surfaces. Currently it is not possible to obtain these results with a traditional UV paint cured with UV arc lamps, as the high quantity of opaque silicas and the type of resins used would give much lower chemical resistance and scratch resistance.

[0166] Using an Excimer lamp without the use of the mechanical system of the present invention it would be possible to obtain excellent performances on the surface but not on the edges.

[0167] The materials and dimensions of the invention as described above, illustrated in the accompanying drawings and claimed below, may be any according to requirements. Furthermore, all the details can be replaced with other technically equivalent ones, without departing from the scope of the present patent application.