EP2022568A2

EP2022568A2 - Machine for painting and pattern printing on flat rigid panels

Info

Publication number: EP2022568A2
Application number: EP08104517A
Authority: EP
Inventors: Gianni Maitan
Original assignee: GE MA TA SpA
Current assignee: GE MA TA SpA
Priority date: 2007-08-07
Filing date: 2008-06-24
Publication date: 2009-02-11
Also published as: EP2022568A3; ITVI20070226A1

Abstract

Herein described is a machine for painting and pattern printing on flat rigid panels, made of glass, metal, wood, plastic and other types of material, of the type in which the panel (1) is arranged on a transport organ (2) usually made up of a rotating cylinder or a sliding belt, arranged oppositely positioned with respect to a painting cylinder (3), which deposits the paint on the underlying panel transported by the abovementioned moveable belt/cylinder. The machine is characterised in that the painting cylinder (3) in absence of the underlying panel (1) is arranged at a distance exceeding the thickness of the panel itself and that, at the beginning of the painting or pattern printing operation, the abovementioned painting cylinder is arranged in contact with the panel moving forward, covering its entire width, in a manner orthogonal to the direction of forward movement of the panel and in a predetermined position, regardless of the thickness of the panel to be painted.

Description

The present finding regards a machine for painting and pattern printing on flat rigid panels made of glass, metal, wood, plastic and other types of material, according to the general part of claim 1.
Known over the years, for painting glass or wood panels, are machines made up of a transport organ, usually made up of a rotating cylinder or of a sliding belt oppositely positioned with respect to a painting cylinder, which deposits the liquid product, in particular paint, on the underlying panel transported by the abovementioned rotating cylinder or sliding belt.
In some models of such machines, in order to imprint patterns or deposit small amounts of paint, the rotation of the printing cylinder has a direction of rotation matching the direction of forward movement of the panel.
In other models of such machines, in order to deposit a high amount of paint, the direction of rotation of the painting cylinder is opposite to the direction of forward movement of the panel.
The chemical product (paint, varnish or other products suitable for the propose) can be spread on the painting cylinder by an additional cylinder which, rotating in a direction opposite or matching the direction of rotation of the painting cylinder, arranged in contact or at a minimum distance from abovementioned painting cylinder, defines a channel within which the paint is held.
In other cases, in particular when the painting cylinder has a grooved surface, the chemical product can be spread on the painting cylinder itself by means of a blade commonly known as "spreader" which determines a channel within which the abovementioned chemical product (paint, varnish or other products) is held.
The machines known to the state of art have revealed some operational drawbacks which jeopardise the good performance of the painting or pattern printing operations.
In machines wherein the printing cylinder rotates in a direction opposite to the direction of forward movement of the panel to be printed, the painting operation is complicated and it usually has some defects on the front inlet border of the panel subjected to the action of the abovementioned painting cylinder.
Specifically, when the border of the rigid panel gets into contact with the cylinder, the upper edge of the panel that first gets into contact with the cylinder itself, scrapes the paint which, dripping on the front border of the panel, causes a considerable painting defect.
Such drawback is due to the fact that, when painting, the thickness of the panel must be greater than the distance measured between the painting cylinder and the underlying transport belt or cylinder.
Furthermore, the machines currently available in the market are not capable of performing partial painting of the upper surface of the panel.
Furthermore, the variation of the thickness of the panel requires manual adjustment of the distance between the painting cylinder and the underlying transport cylinder or belt.
This implies that, in order to obtain non-painted zones of the panel surface, protection films - which are removed upon completion of the painting operations - must be glued on the surface of the panel in advance; obviously, said operation requires long processing times and extra expenses.
An objective of the present finding is that of providing a machine for painting and pattern printing on rigid panels, in particular on glass panels, free of the operation drawbacks observed on the roller painting machines of the known type.
Such objective is attained by means of a machine for painting and pattern printing on rigid panels where the printing cylinder, in the absence of the underlying panel, is arranged at a greater distance with respect to the thickness of the panel itself.
At the beginning of the painting operation the painting cylinder is arranged in contact covering the entire length of the panel moving forward at a position arranged at the upper edge of the front border of panel, or at a portion immediately subsequent to the abovementioned edge, or at any of the internal zones of the panel itself, defined previously and with a width defined previously.
In this manner, the ideal contact between the two surfaces - that of the painting cylinder and that of the panel - in mutual movement is always obtained even in case the thicknesses of the panel to be painted have different values.
The machine is provided with a system for detecting the presence and the thickness of the panel which, through an electronic programme, operates a mechanism which moves the printing cylinder alone or the cylinder or the transport and contrast belt alone, or both, in a vertical direction in such a manner to arrange the painting cylinder and the cylinder or the transport and contrast belt at a distance smaller or equivalent to the thickness of the of the panel to be painted and at a predetermined zone of the panel, arranged in an orthogonal manner with respect to the direction of forward movement of the panel itself and at one of the positions described previously.
Furthermore, said electronic programme also determines the period of contact of the painting cylinder with the panel, determining, in such manner, the width and the repetitiveness of the portion of the painted surface of the panel.
The finding shall be further defined through the description of one of its possible embodiments, strictly provided for exemplifying and non-limiting purposes with the help of the attached drawings, wherein;

Figures 1, 2, 3, 4 (tab. I) represent three different initial operation steps of the machine subject of the finding:

Figures 5, 6 (tab. II) represent the plan view of the machine subject of the finding, at two different operation modes:

Figures 7, 8 (tab III) represent two different constructions of the machine subject of the finding.

Referring to the figures, the machine for painting and pattern printing on rigid panels 1 is substantially made up of an organ for drawing the abovementioned panel, indicated in its entirety with reference 2 oppositely positioned with respect to a painting cylinder 3, for defining the passage section 4 of the panel 1.
When painting or pattern printing, the panel 1 must be in contact with the painting cylinder 3, which provides for depositing - on the surface of the abovementioned panel - a uniform layer of the liquid product "P", previously spread on the surface of the cylinder itself.
The printing cylinder 3 may rotate in a direction matching the direction of forward movement of the panel 1, or (as illustrated) in a direction opposite to the abovementioned direction.
Operatively, the machine subject of the finding obtains the initial contact between panel 1 and the painting cylinder 3 along a line of tangency "K" arranged in a perpendicular manner with respect to the direction of forward movement of the panel and arranged at the upper edge of the front border 10 of the panel (fig 2), or at a portion 11, arranged immediately after the abovementioned border (fig. 3) or, still, at any one of the predetermined zones 12, arranged more internally on the same panel (fig. 4) and for a programmed period of time, in such a manner to paint the surface of the panel fully or partially.
In order to ensure that that the contact between the panel 1 and the painting cylinder 3 occurs at the predetermined zone of the panel, the finding provides for that the machine be provided, upstream of the painting cylinder, with an electronic sensor 6, which detects the presence and the thickness of the panel and, through an electronic programme, operates a mechanism which reduces the distance 4 between the painting cylinder and the transport/contrast cylinder or belt to a value equivalent or smaller than the thickness of the panel to be painted, in such a manner to provide the ideal contact between the cylinder and the panel itself.
At the end of the painting or pattern printing operation, the painting cylinder 3, or the transport/contrast cylinder or belt 2, or both, move away from each other, returning to the initial position.
Such movement and thus the contact between the painting cylinder and the panel might occur on the panel 1 only once, after the entire surface of the panel itself has been completely painted or painted on only one band 100, or it might occur several times, in such a manner to provide a series of painted bands 101, 102, 103, all having the same width and equally spaced from each other or having a different width "L" and differently spaced from each other "X".
In a first preferred embodiment, the organ 2.1 for drawing the panel 1 is made up of a rubber belt 20, which lies on a roller 21, which is arranged in a parallel manner with respect to the upper painting cylinder 3, said belt being operated by a control group 22, which operates on the exit roller 23.
In a second preferred embodiment, the drawing organ 2.2 is made up of a roller table 25, arranged upstream and downstream of a rubber roller 26, arranged aligned with respect to an upper painting cylinder 3 and operated by a control group 27, applied directly on said roller.
Furthermore, in case of panels 1 having low thicknesses which allow such flexibility to be planar under the action of the painting cylinder 3, said cylinder is made of steel, with the external surface smooth or grooved.
On the contrary, in case of panels 1 having such thicknesses not to allow the abovementioned flexibility of the panel 1 the painting cylinder 3 is made with a rubber, smooth or grooved external surface.
Obviously, the machine subject of the finding can be made in very different shapes and sizes depending on the intended use and the components employed without, for this reason, departing from the scope of the following claims.

Claims

MACHINE FOR PAINTING AND PATTERN PRINTING ON FLAT RIGID PANELS, made of glass, metal, wood, plastic and other types of materials, of the type in which the panel (1) is arranged on a transport organ (2), usually made of a rotating cylinder or a sliding belt, arranged oppositely positioned with respect to a painting cylinder (3), which deposits the paint on the underlying panel transported by the abovementioned moveable cylinder or belt; being provided for that the painting cylinder (3) has a direction of rotation matching the direction of forward movement of the panel (1), or that the direction of rotation of the painting cylinder (3) be opposite to the direction of forward movement of the panel (1); the chemical product (paint, varnish or other products suitable for the purpose) being spread on the painting cylinder (3) by an additional cylinder which, rotating in a direction opposite or matching the direction of rotation of the painting cylinder, being arranged in contact or at a minimum distance from the abovementioned painting cylinder, defines a channel within which the paint is held, being provided for, alternatively, that when the painting cylinder (3) has a grooved surface, the chemical product be spread on the painting cylinder itself by means of a blade, commonly referred to as spreader, which determines a channel within which the abovementioned chemical product (P) is held,
said machine being characterised in that
the painting cylinder (3), in the absence of the underlying panel (1), is arranged at a greater distance with respect to the thickness of the panel itself and in that at the beginning of the painting or pattern printing operation, the abovementioned painting cylinder is arranged in contact with the panel moving forward, covering its entire length, in an orthogonal manner with respect to the direction of forward movement of the panel and at a predefined position, regardless of the thickness of the panel to be painted.
MACHINE FOR PAINTING AND PATTERN PRINTING ON FLAT RIGID PANELS, according to claim 1, characterised in that the initial contact zone between the panel (1) and the painting cylinder (3) occurs along a line of tangency (K), arranged in a perpendicular manner with respect to the direction of forward movement of the panel and arranged at the upper edge of the front border (10) of the panel itself.
MACHINE FOR PAINTING AND PATTERN PRINTING ON FLAT RIGID PANELS, according to claim 1, characterised in that the initial contact zone between the panel (1) and the painting cylinder (3) occurs at a portion (11), arranged immediately after the front border (10) of the panel itself.
MACHINE FOR PAINTING AND PATTERN PRINTING ON FLAT RIGID PANELS, according to claim 1, characterised in that the initial contact position between the panel (1) and the painting cylinder (3) occurs at any one of the predetermined zones (12), arranged internally on the panel itself, for a predetermined period of time and several times on a same panel, at a predetermined frequency.
MACHINE FOR PAINTING AND PATTERN PRINTING ON FLAT RIGID PANELS, according to one or more of the preceding claims, characterised in that it is provided with a system with for detecting the presence and the thickness of the panel (1) which, through an electronic programme, operates a mechanism which moves the painting cylinder (3) alone in a vertical direction, in such a manner to arrange the painting cylinder (3) and the transport/contrast cylinder or belt (2) at a distance equivalent or smaller than the thickness of the panel to be painted and in a predetermined zone.
MACHINE FOR PAINTING AND PATTERN PRINTING ON FLAT RIGID PANELS, according to one or more of the preceding claims, characterised in that it is provided with a system for detecting the presence and the thickness of the panel (1) which, through an electronic programme, operates a mechanism which moves the transport/contrast cylinder or belt (2) alone in a vertical direction, in such a manner to have between the painting cylinder(3) and the transport/contrast belt or cylinder (2) a distance equivalent or smaller than the thickness of the panel to be painted in a predetermined zone.
MACHINE FOR PAINTING AND PATTERN PRINTING ON FLAT RIGID PANELS, according to one or more of the preceding claims, characterised in that it is provided with a system for detecting the presence and the thickness of the panel (1) which, through an electronic programme, operates a mechanism which moves the painting cylinder (3) and the transport/contrast cylinder or belt (2) in vertical direction, in such a manner to have between the painting cylinder (3) and the transport/contrast cylinder or belt (2) a distance equivalent or smaller than the thickness of the panel to be painted in a predetermined zone.
MACHINE FOR PAINTING AND PATTERN PRINTING ON FLAT RIGID PANELS, according to one or more of the preceding claims, characterised in that it provides for, upstream of the painting cylinder (3), an electronic sensor (6), which detects the presence and the thickness of the panel (1) and operates, through an electronic programme, which operates a mechanism which reduces the distance (4) between the painting cylinder (3) and the transport/contrast cylinder or belt (2) to a value equivalent or smaller than the thickness of the panel to be painted, in such a manner to provide the ideal contact between the cylinder and the panel itself in a predetermined zone.
MACHINE FOR PAINTING AND PATTERN PRINTING ON FLAT RIGID PANELS, according to one or more of the preceding claims, characterised in that at the end of the painting or pattern printing operation, the printing cylinder (3) raises, returning to the initial position.
MACHINE FOR PAINTING AND PATTERN PRINTING ON FLAT RIGID PANELS, according to claim 9, characterised in that the operation of moving the printing cylinder (3) away from the panel (1) occurs several times on a same panel, in such a manner to provide a trail of painted bands (101, 102, 103).
MACHINE FOR PAINTING AND PATTERN PRINTING ON FLAT RIGID PANELS, according to one or more of the preceding claims, characterised in that the transport and contrast organ (2.1) of the panel (1) is made up of a rubber belt (20), which lies on a roller (21) which is arranged in a manner parallel to the upper painting cylinder (3), said belt being operated by a control group (22) which operates on the exit roller (23).
MACHINE FOR PAINTING AND PATTERN PRINTING ON FLAT RIGID PANELS, according to one or more of the preceding claims, characterised in that the transport/contrast organ (2.2) of the panel (1) is made up of a roller table (25), arranged upstream and downstream of a rubber roller (26), arranged aligned with the upper painting cylinder (3) and operated by a control group (27), applied directly on said roller.
MACHINE FOR PAINTING AND PATTERN PRINTING ON FLAT RIGID PANELS, according to one or more of the preceding claims, characterised in that the painting cylinder (3) is made with a rubber, smooth or grooved external surface.