Apparatus and method for the drying/curing of chemical products

Abstract

An apparatus for matting a coating applied on mainly flat panels includes a cleaning workstation and an excimer treatment workstation where the panels are conveyed by a belt conveyor having an upper outward section and a lower return section. In the cleaning workstation, the upper outward section of the belt conveyor has a V-shaped path, which is formed by two rollers in contact with the plane of advancement of the panel, and a roller in lower position, and which is bridged by advancing rollers, among which gaseous nitrogen is supplied that brushes all sides of the panel. In the treatment workstation, the upper outward section of the belt has a V-shaped path, where the panel is irradiated by an excimer emitter, and which is formed by two rollers in contact with the plane of advancement of the panel, and a roller in lower position, and is bridged by advancing rollers.

Claims

1. An apparatus (100) for matting a coating applied on mainly flat panels (10), comprising: a cleaning workstation (300); and an excimer treatment workstation (500), wherein said panels (10) are conveyed by a belt conveyor (30) provided with an upper outward section (31) and a lower return section (32), wherein in said cleaning station (300) the upper outward section (31) of said belt conveyor (30) has a V-shaped path defined by three rollers (41, 42, 43), of which a first roller (41) and a third roller (43) are in contact with a panel advancing plane, and a second roller (42) is placed lower than the first and the third roller (41, 43), and wherein, in correspondence of the V-shaped path a panel (10) moves on at least two advancing rollers, among which gaseous nitrogen is supplied, brushing all the sides of the panel.

2. The apparatus according to claim 1, wherein, in said excimer treatment workstation (500), the upper outward section (31) of the belt conveyor has a second V-shaped path formed by a group of three rollers (4G, 42′, 43′), of which a first (4G) and a third roller (43′) are in contact with the panel advancing plane, and a second roller (42′) is placed lower than the first and the third roller (41, 43), and wherein, in correspondence of the V-shaped path in said excimer treatment workstation (500), said panel (10) moves on at least two advancing rollers, and said panel (10) is irradiated by an excimer emitter (56).

3. The apparatus (100) according to claim 1, wherein one of the advancing rollers in the cleaning workstation (300) or the excimer treatment workstation (500) is provided with a plurality of biconical sectors with reflecting surfaces.

4. The apparatus (100) according to claim 2, wherein the first and the second advancing rollers (5G, 53′) in the excimer treatment workstation (500) are motorized and made of mirror-polished metal.

5. The apparatus (100) according to claim 1, wherein the advancement of said panel (10) occurs inside an inert chamber (120) supplied with gaseous nitrogen, supplied by a plurality of laminar devices (60, 61, 62, 63, 64).

6. The apparatus (100) according to claim 1, wherein said excimer treatment workstation is supplied by an excimer emitter (56) placed inside the excimer treatment workstation (500).

7. The apparatus (100) according to claim 1, wherein, at an entrance of said panel (10) into the apparatus (100), there is provided an initial workstation supplying nitrogen (200).

8. A treatment method for matting a coating applied to panels (10) making use of the apparatus (100) according to claim 1, comprising the following steps: c) inserting the panel (10), coated with a UV coating and previously gelled, inside said apparatus (100) in inert atmosphere, conveying the panel towards the cleaning workstation (300); d) cleaning said coated and gelled panel (10) with gaseous nitrogen, so as to remove oxygen molecules deriving from natural atmosphere; e) conveying said panel (10) in an inert atmosphere toward the excimer treatment workstation (500); f) irradiating said panel (10) with excimer light in an inert atmosphere; and g) conveying the panel (10) out of the excimer treatment apparatus (100) in the natural atmosphere again.

9. The treatment method according to claim 8, further comprising the following steps upstream of step c): a) Coating the panel (10) on five sides comprising a plan side and four lateral edges of the panel with a coating containing polymerizable monomers and a photoinitiator sensitive to UV radiation; and b) Optionally, gelling the coated panel through UV radiation.

10. The treatment method according to claim 8, further comprising the following step downstream of step g): h) Optionally, completely polymerizing said panel, using a second apparatus placed downstream of said apparatus (100) according to claim 1.

Description

[0034] Further advantages and properties of the present invention are disclosed in the following description, in which exemplary embodiments of the present invention are explained in detail on the basis of the drawings:

[0035] FIG. 1 Example of a raised panel, axonometric view;

[0036] FIG. 2 Longitudinal section of the apparatus according to the present invention;

[0037] FIG. 3 Longitudinal section of a detail of the cleaning workstation;

[0038] FIG. 4 Axonometric view of a detail of the treatment workstation;

[0039] FIG. 5 Transversal section of the treatment workstation.

[0040] FIG. 1 shows an axonometric view of an example of a raised furniture door. A panel 10 is provided with two main sides, the upper side 1 and its opposed side, which is not visible in the Figure; a head edge 2, a tail edge 5 and two longitudinal edges 3 and 4. The raising is clearly visible in the Figure on the main side 1. In the present description, overall the head edge 2, the tail edge 5 and the two longitudinal right 3 and left edge 4 are grouped in the term lateral edges. Coating five out of six sides of the panel 10 means coating the main side 1 and the lateral edges 2, 3, 4, 5.

[0041] FIG. 2 shows a longitudinal section of an apparatus 100 for matting panels through excimer treatment according to the present invention. The advancing of the panel 10 inside the apparatus 100 occurs in the direction indicated by the bold arrow, in an inert atmosphere supplied with gaseous nitrogen. Said apparatus 100 comprises a plurality of housings 20 intended for insulating the panels from natural atmosphere, keeping them inside an inert chamber 120, better visible in FIG. 5. The assembly of the housings 20 forms a tunnel-like chamber 120 extending in the advancement direction of the upper outward section of a belt conveyor.

[0042] Moreover, the apparatus 100 comprises an initial workstation 200 for supplying gaseous nitrogen, a cleaning workstation 300 and a treatment workstation 500.

[0043] Said apparatus 100 further comprises a belt conveyor 30 covered with a section covering formed by said housings 20 intended for providing an inert chamber.

[0044] The closed belt 30 causes the advancement of panels 10 to be treated. The closed belt 30 is provided with the known shape, providing an upstream outward section 31 and a lower return section 32, actuated by end rollers 21 and 22, of which the roller 21 is a motorized roller, while the roller 22 is an idle roller.

[0045] Upstream the apparatus 100 the panels 10 are coated on five sides (main side 1 and all lateral edges 2, 3, 4, 5), preferably spray-coated. The coating contains polymerizable monomers in a suitable solvent, and a photoinitiator sensible to UV radiation. Again upstream said apparatus 100, successively the coating applied on the panel 10 preferably undergoes a gelling treatment, preferably through an UV LED lamp.

[0046] FIG. 3 shows a detail of the initial workstation 200 for providing gaseous nitrogen, placed at the entrance of panels 10 into apparatus 100. Said initial workstation 200 comprises at least a device 60, preferably two devices 60 for supplying gaseous nitrogen in the initial portion of the panels path.

[0047] Moreover, FIG. 3 shows a detail of the cleaning workstation 300 in a lateral section. Inside the cleaning workstation, the upper outward section 31 for conveying panels 10 takes a V shape thanks to three rollers: a first roller 41, a second roller 42, and a third roller 43. The two first and third rollers 41 and 43 lie on the same plane, and are placed immediately under the upper outward section 31 of the belt conveyor 30, and therefore immediately under the advancement plane of panels 10. The second roller 42 lies on a plane lower than the plane of rollers 41 and 43, so forming a V-shaped path of the upper outward section 31 of the belt conveyor 30.

[0048] The panels 10 advance in the direction indicated by the bold arrow, lying with their (non-coated) bottom side on three motorized advancing rollers 51, 52, 53. After said rollers, the panels are again supported by the upper outward section 31 of the belt conveyor. Said rollers 51, 52, 53 are smooth metal rollers.

[0049] Above the advancing plane of panels 10 there are provided two devices 61, 62 for supplying gaseous nitrogen, while under the advancing plane there is provided a third device 63, and optionally a fourth device 64 for supplying gaseous nitrogen.

[0050] Said devices 61, 62, 63, 64 for supplying gaseous nitrogen are as long as the width of the belt conveyor 30, and anyway are provided with a length longer than the panel to be treated; they supply gaseous nitrogen in a laminar way, which brushes all the surfaces of the panel 10.

[0051] Overall, the devices 61, 62, 63, 64 supplying gaseous nitrogen constitute the cleaning workstation 300 of the panel 10, intended for removing as much as possible from the surfaces 1, 2, 3, 4, 5 of the panel to be treated the oxygen molecules deriving from the natural atmosphere outside the apparatus 100.

[0052] Inside the cleaning workstation 300 there are preferably provided pipes 57 for suctioning the oxygen removed from the surface of the panel 10 thanks to the nitrogen supply, and a (not shown) suctioning device, intended for removing oxygen from the chamber 120.

[0053] Once the panel 10 is beyond the cleaning workstation 300 and is supported again by the upper outward section 31 of the conveyor belt 30, the panel continues its conveying towards the excimer treatment workstation 500. Such conveying occurs obviously inside the chamber 120 containing an inert atmosphere (nitrogen).

[0054] FIG. 4 shows the treatment workstation 500 in an axonometric view. Said treatment workstation 500 is provided with a structure analogue to that of the cleaning workstation 300, with a similar V-shaped path formed by the upper outward section 31 thanks to the presence of three rollers: a first roller 41′, a second lower roller 42′, and a third roller 43′, analogue to the above-described rollers 41, 42, 43.

[0055] The panels 10 advance in the direction indicated by the bold arrow, and their bottom (non-coated) side is supported by three motorized rollers 51′, 54, 53′. Subsequently, the panels 10 are supported by the upper outward section 31 of the belt conveyor again.

[0056] The three advancing motorized rollers 51′, 54, 53′ allow the advancing of the panels 10 analogously to the advancing motorized rollers 51, 52, 53 of the cleaning workstation 300. Nonetheless, they have a worked surface intended for diffusing the radiations emitted by an excimer emitter 56 for the treatment of the surfaces 1, 2, 3, 4, 5 of panels 10, as better explained in the following.

[0057] The rollers 51 and 53 are metal, mirror-polished rollers intended for diffusing the radiations emitted by the excimer emitter 56 for matting the head 2 and tail edges 5 of panels 10.

[0058] The roller 54, differently from roller 52, is provided with a reflecting, cone-shaped surface. The cone-shaped surface is intended for diffusing the radiations emitted by the excimer emitter 56 for the matting treatment, mainly for matting the longitudinal edges 3 and 4 of panels 10.

[0059] The excimer emitter 56 (visible in FIGS. 2 and 5) is a UV light source produced by the spontaneous emission of excimer molecules (excited dimers). In particular, in a preferred embodiment the wavelength used for this specific application is 172 nm, produced preferably by a xenon lamp. Nonetheless, excimer emitters emitting a slightly different wavelength can be used, inside a 165-185 nm range.

[0060] FIG. 5 shows a transversal section of the cleaning workstation 500 taken at the height of the advancing roller 54. Said Figure allows to better appreciate the geometry of the advancing roller 54, comprising a plurality of mirror cones, capable of reflecting the light emitted by the excimer emitter 56. FIG. 5 also allows to appreciate the chamber 120 for panel conveying, closed and provided with inert atmosphere.

[0061] Once a panel 10 underwent the matting treatment through the excimer emitter 56, it continues on the final portion of the upper outward section 31 of the belt conveyor 30, and then leaves the apparatus 100 toward the subsequent workstation.

[0062] The matting method through excimer treatment comprises the following steps: [0063] a) Coating a panel 10 preferably on five of its sides (main side 1 and lateral edges 2, 3, 4, 5), preferably spray-coating with a coating containing polymerizable monomers and a photoinitiator sensitive to UV radiation; [0064] b) Optionally gelling the coating layer through UV radiations, preferably in a natural atmosphere; [0065] c) Inserting the coated and gelled panel inside the treatment apparatus 100 in inert atmosphere, conveying it toward a cleaning workstation 300; [0066] d) Cleaning the coated and gelled panel with gaseous nitrogen, intended for removing the oxygen molecules deriving from natural atmosphere; [0067] e) Conveying said panel 10 in inert atmosphere toward the excimer treatment workstation 500; [0068] f) Irradiating said panel 10 with excimer radiation in inert atmosphere; [0069] g) Conveying the matted panel outside the treatment apparatus 100, in natural atmosphere again; [0070] h) Optionally, definitively polymerizing the matted panel through an apparatus placed downstream the apparatus 100 according to the present invention.

[0071] The above-described method is the preferred embodiment for matting panels. Nonetheless, in an alternative embodiment, the gelling of the coating layer (step b) occurs in inert atmosphere inside the chamber 120 for conveying panels placed in the apparatus 100 according to the present invention. A further UV lamp is inserted for gelling downstream the initial workstation 200 for supplying nitrogen, but upstream the excimer treatment workstation 500, preferably between the cleaning workstation 300 and the treatment workstation 500. [0072] 1 main side [0073] 2 head edge [0074] 3 right longitudinal edge [0075] 4 left longitudinal edge [0076] 5 tail edge [0077] 10 panel [0078] 20 housing [0079] 21 motorized roller [0080] 22 idle roller [0081] 30 belt conveyor [0082] 31 upper outward section [0083] 32 lower return section [0084] 41 first roller [0085] 42 second roller [0086] 43 third roller [0087] 51 first advancing roller [0088] 52 second advancing roller [0089] 53 third advancing roller [0090] 54 worked second advancing roller [0091] 56 excimer emitter [0092] 57 pipes for oxygen suctioning [0093] 60 initial nitrogen supplying device [0094] 61 first nitrogen supplying device [0095] 62 second nitrogen supplying device [0096] 63 third nitrogen supplying device [0097] 64 fourth nitrogen supplying device [0098] 100 apparatus according to the present invention [0099] 120 conveying chamber [0100] 200 initial nitrogen supplying workstation [0101] 300 cleaning workstation [0102] 500 excimer treatment workstation