MACHINE FOR THE FLAT MOUNTING OF FLEXOGRAPHIC PRINTING PLATES

Abstract

A machine for flat mounting of flexographic printing plates, comprising a base, a table, supported by said base, defining a support surface for mounting a printing plate on a respective support. The table comprises a front side, a rear side and two opposing sides. The machine also comprises parallel lateral guides, provided along the sides of the table, a carriage slidingly engaged in the lateral guides, a pressure roller associated with the carriage, to determine the adhesion of the printing plate on the respective support, and a vacuum generation system, to constrain the support to the surface of the table, during mounting of the printing plate. The machine comprises at least one layer of fabric, or breathable material, positioned on the surface of the table, on the upper surface of which the support is intended to be positioned, for the subsequent mounting, on it, of the printing plate.

Claims

1. Machine for flat mounting of flexographic printing plates, comprising a base, a table, supported by said base, defining a support plane for mounting a printing plate on a respective support, said table comprising a front side, a rear side and two opposing sides, parallel lateral guides, provided along said sides of said table, a carriage slidingly engaged in said lateral guides, a pressure roller associated with said carriage, to determine the adhesion of the printing plate on the respective support, a vacuum generation system, to constrain the support to the surface of the table, during mounting of the printing plate, at least one layer of fabric or breathable material, positioned on the surface of the table, on the upper surface of which the support is intended to be positioned, for the subsequent mounting of the clich on it.

2. Machine according to claim 1, wherein said layer of fabric, or breathable material, is porous.

3. Machine according to claim 2, wherein said fabric, or breathable material, is natural or synthetic.

4. Machine according to claim 3, wherein said fabric, or breathable material, is of the woven pile type, such as carpet or the like.

5. Machine according to claim 1, comprising fastening means for attaching said layer of fabric, or breathable material, to the surface of said table.

6. Machine according to claim 5, wherein said fastening means comprise strips of double-sided tape, interposed between the surface of said table and said layer of fabric, or breathable material.

7. Machine according to claim 1, wherein said vacuum generation system comprises a plurality of upper holes, which affect said table.

8. Machine according to claim 7, wherein said upper holes of said table communicate with respective lower holes provided in respective channels positioned underneath said table.

9. Machine according to claim 8, wherein said channels are supported, parallel to each other, by said table, and are arranged so as to achieve a certain distribution of said lower holes, and therefore also of said upper holes, over the entire surface of said table.

10. Machine according to claim 9, wherein said channels are placed in communication, via respective ducts, with one or more pumps of said vacuum generation system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] These and further advantages will be better understood by any person skilled in the art from the following description and the attached drawings, given as a non-limiting example, in which:

[0032] FIG. 1 is a schematic axonometric view of the machine according to the invention;

[0033] FIG. 2 is another axonometric view of the same machine, from a different angle;

[0034] FIG. 3 is an isometric view of the machine, with the carriage removed for clarity;

[0035] FIG. 4 is an isometric view of the machine with the carriage and layer of fabric, or breathable material, removed for clarity;

[0036] FIG. 5 is a detailed isometric view of the machine with the table removed for clarity;

[0037] FIG. 6 is an isometric view of the machine with the carriage removed and the layer of fabric, or breathable material, lifted off the table;

[0038] FIG. 7 is an axonometric view of the machine with the support, and the respective printing plate, positioned on the layer of fabric, or breathable material;

[0039] FIG. 8 is a detailed and sectioned axonometric view of the machine, with the support, and the respective printing plate, positioned on the layer of fabric, or breathable material.

EMBODIMENTS OF THE INVENTION

[0040] With reference to FIGS. 1, 2, the numeral 1 generally indicates a machine for the flat mounting of flexographic printing plates according to the present invention.

[0041] Machine 1 has a base, indicated overall with 2.

[0042] The machine also includes a table 3, supported by the base 2.

[0043] Table 3 defines a support surface for mounting a printing plate 4 on a respective support 5 (for example made of Mylar, or other similar material), by interposing a double-sided adhesive material.

[0044] In more detail, on table 3 it is possible to position support 5, as well as printing plate 4 on the latter, in such a way as to superimpose the position references provided on printing plate 4 itself on corresponding crosses on the monitors of cameras 16, 17: this, therefore, allows checking the correct assembly of printing plate 4 on support 5.

[0045] Conventionally, and with reference to the normal conditions of use of machine 1, table 3 comprises a front side 6, a rear side 7, and two opposing sides 8.

[0046] Machine 1 also includes parallel lateral guides 9, which are provided along the sides 8 of table 3.

[0047] Machine 1 also includes a carriage 10.

[0048] The carriage 10 is engaged, in a sliding manner, in the aforementioned lateral guides 9.

[0049] Carriage 10 has a substantially portal or bridge structure.

[0050] Carriage 10 can, therefore, move over the entire surface of table 3.

[0051] Carriage 10 comprises, in more detail, a horizontal crosspiece 11 and two opposing vertical uprights 12, slidingly engaged in the lateral guides 9.

[0052] Carriage 10 supports, in a rotatable manner, at least one pressure roller 13.

[0053] The pressure roller 13 has the function of exerting a pressure of a predetermined amount on the surface of the printing plate 4, so that the latter adheres perfectly to the respective support 5 (thus also eliminating any air bubbles trapped between them).

[0054] Machine 1 comprises a vacuum generation system, indicated overall with 14 (FIG. 5), to constrain the support 5 to the surface of the table 3, during the assembly of the printing plate 4.

[0055] The machine 1 also comprises optical means, indicated overall by 15, for checking the mounting position of the printing plate 4 on the respective support 5.

[0056] In more detail, the optical means 15 comprise a first camera 16 and a second camera 17, suitable for checking the mounting position of respective references provided on the printing plate 4 with respect to corresponding references provided on the support 5.

[0057] The optical means 15 also comprise an upper guide 18, fixed to the carriage 10 (in correspondence with the front side 6 of the table 3), to which the first camera 16 and the second camera 17 are associated.

[0058] The first camera 16 and the second camera 17 can be moved along the upper guide 18 manually or automatically, by means of respective drive units.

[0059] The first camera 16 and the second camera 17 are movable in a direction perpendicular to that of the lateral guides 9 (and therefore in a transverse direction with respect to the table 3).

[0060] In use, the first camera 16 and the second camera 17 film, from above, respective pre-set mounting areas of the support 5, or of the printing plate 4.

[0061] The optical means 15 further comprise a central monitor 19, fixed to the carriage 10, to which the first camera 16 and the second camera 17 are operationally connected.

[0062] The central monitor 19 is visible to the operator when he is positioned at the front side 6 of the table 3.

[0063] The central monitor 19 allows the operator to view, enlarged, the images taken by the cameras 16, 17 themselves, in order to check/modify the positioning of the printing plate 4 with respect to the support 5.

[0064] The machine 1 also includes a user interface U for controlling and managing the entire operation; the user interface U is fixed to the table 3, or to the base 2, at the front side 5 of the table 3 itself.

[0065] The machine 1 may also include a second monitor 20, positioned opposite the central monitor 19 with respect to the carriage 10 (i.e., visible from the opposite side with respect to the central monitor 19, when the operator is located at the rear side 7).

[0066] The second monitor 20 allows the operator to view the images captured by the cameras 16, 17 even when working at the rear side 7 of the table 3.

[0067] It should be emphasized that all the movements of machine 1 (mainly those of the carriage 10, the pressure roller 13, the cameras 16, 17, etc.) can be manual or automated, managed by respective actuators operationally connected to the central control unit of machine 1.

[0068] With particular reference to FIGS. 4 and 5, the vacuum generation system 14 comprises a plurality of upper holes 21, which affect the table 3.

[0069] The upper holes 21 of the table 3 communicate with respective lower holes 22 provided in respective channels 23 positioned underneath the table 3.

[0070] The channels 23 are supported, parallel to each other, by the table 3, and they are arranged in such a way as to create a certain distribution of the lower holes 22, and therefore also of the upper holes 21, over the entire surface of the table 3.

[0071] The channels 23 are placed in communicationvia respective ducts 24with one or more pumps of the vacuum generation system 14, not visible in the attached figures.

[0072] According to one aspect of the invention, machine 1 comprises at least one layer of fabric 25 or breathable material, positioned on the surface of the table 3.

[0073] On the upper surface of the fabric layer 25, or breathable material, the support 5 is intended to be positioned, for the subsequent mounting, on it, of the printing plate 4.

[0074] Advantageously, and surprisingly, the applicant has observed that the layer of fabric 25, or breathable material, placed in direct contact with the surface of the table 3and therefore with the upper holes 21 of the vacuum generation system 14allows for a notable increase in the performance of the vacuum generation system 14 itself, and therefore its effectiveness in obtaining the adhesion of the support 5 to the surface of the layer of fabric 25, or breathable material, itself.

[0075] The layer of fabric 25, or breathable material, can be sized to cover the entire surface of the table 3, or possibly just a portion of it, depending on the specific usage requirements.

[0076] Furthermore, in accordance with another aspect of the invention, the fabric layer 25, or breathable material, is porous.

[0077] In more detail, the applicant observed that the porosity of the fabric layer 25, or breathable material, allows for the effect of the activation of the vacuum generation system 14 to be increased and intensifiedin a very evident and therefore decisive waycompared to what can be obtained with the solutions existing to date.

[0078] This beneficial effect has been observed specifically when using very thick supports (e.g. 0.7 mm and above), which are therefore considerably rigid and elastic.

[0079] The fabric used to make layer 25, or breathable material, can be natural or synthetic.

[0080] For example, in a preferred, but not exclusive, embodiment of the invention, the fabric used to make the layer 25, or breathable material, may be of the woven pile type (such as carpet, or the like).

[0081] According to another aspect of the invention, the machine 1 comprises fastening means 26 of the layer of fabric 25, or breathable material, to the surface of the table 3.

[0082] The aforementioned fastening means 26which prevent, in fact, any movement of the fabric layer 25, or breathable material, with respect to the table 3 itselfcan be of any suitable type.

[0083] More specifically, in an embodiment of the invention of particular practical interestand illustrated in the attached figuresthe fastening means 26 comprise strips of double-sided tape 27, placed between the surface of the table 3 and the layer of fabric 25, or breathable material.

[0084] For exampleas shown in FIG. 6the double-sided tape strips 27 can be positioned peripherally on the surface of the table 3, i.e. along its sides.

[0085] In an alternative embodiment, the fastening means 26 could comprise metal profiles fixed along the edges of the table 3, overlapping the end edges of the fabric layer 25, or breathable material.

[0086] The method of use and operation of the machine 1 according to the invention is, in light of what has been described, the following.

[0087] For better understanding, please refer to FIG. 6, which shows an enlarged section of the machine 1 according to the invention.

[0088] The support 5 is first positioned on the surface of the fabric layer 25, or breathable material; the positioning of the support 5 is facilitated by its folded terminal edge 28, which is hooked at a special profile 29 provided at the front side 6 of the machine 1.

[0089] Simultaneously with this positioning, or even before it, the vacuum generation system 14 of machine 1 is activated.

[0090] Thanks to the presence of the fabric layer 25, or breathable material, on the table 3 of the machine 1, surprisingly, the effect of the activation of the vacuum generation system 14 is increased and amplified, even in areas of the surface of the table 3 that are devoid of the upper holes 21.

[0091] Therefore, thanks to the presence of the fabric layer 25, or breathable material, the support 5 (even if of high thickness, for example 0.7 mm or more) remains perfectly adhered to the table 3 over its entire surface. At this point the printing plate 4 can be fixed on the surface of the support 5, with the interposition of double-sided tape (obviously, with the aid of the optical means 15).

[0092] Following this, and once the correct positioning of the printing plate 4 has been achieved, the pressure roller 13 of the carriage 10 is activated, in order to obtain perfect adhesion of the printing plate 4 on the support 5, and to eliminate any air bubbles trapped between the two parts.

[0093] Once assembly is complete, the vacuum generation system 14 can be deactivated, and the support 5, together with the printing plate 4, can be removed to be positioned on a printing cylinder.

[0094] It has thus been seen how the invention achieves the proposed objectives.

[0095] The solution according to the present invention allows for the effective and reliable mounting of a flexographic printing plate 4 on a respective Mylar support 5, even if the latter is of relatively high thickness (for example, 0.7 mm and above).

[0096] The support 5, even if relatively thick, remains stably attached to the table 3 of the machine 1 throughout the assembly phase, even, and above all, during the passages of the pressure roller 13.

[0097] This result is achieved, surprisingly, with a technically very simple and extremely economical solution, which can also be implemented on existing machines, without any limitations or impediments.

[0098] The present invention has been described according to preferred embodiments, but equivalent variants can be conceived without departing from the scope of protection offered by the following claims.