WO2002087893A1

WO2002087893A1 - A support for the decorative printing of surfaces, particularly of ceramic materials and the like

Info

Publication number: WO2002087893A1
Application number: PCT/EP2001/009895
Authority: WO
Inventors: Mauro Cestari
Original assignee: Arktype S.R.L.
Priority date: 2001-04-26
Filing date: 2001-08-28
Publication date: 2002-11-07

Abstract

A support for the decorative printing of surfaces (2) is described, having a plate-like silicone structure on one face (3) of which is distributed a colouring substance to be transferred onto said surface (2), and comprising a reinforcing structure (6) at least partially embedded in the plate-like structure.

Description

A support for the decorative printing of surfaces, particularly of ceramic materials and the like Technical field

The present invention relates to a support for the decorative printing of surfaces, particularly of ceramic materials and the like, according to the preamble of the main claim. Technological background

The invention is particularly, although not exclusively, designed for the decorative printing of surfaces of ceramic materials and the like, but equally advantageously it lends itself to being applied in all those fields in which it is necessary to print characters or decorative figures on surfaces for example of products or in the field of advertising posters.

In the technical field of decorative printing of surfaces, so-called "contact" printing is known, in which provision is made for there to be contact between the support or printing means and the surface to be decorated. A first known printing methodology provides for the use of printing rollers on the outer surface of which is wound a silicone tape. On the tape is distributed the colouring substance, for example an ink or similar pigment, which is transferred onto the surface to be decorated by contact of the silicone tape on the surface itself. The advantage of selecting a silicone-based printing support in tape form lies on the one hand in the distinct water-repellent characteristics of the silicone which facilitate the distribution and the transfer of the typically water-based inks onto the surfaces to be decorated, and on the other hand in its relative elasticity, which avoids the occurrence of localised overloads on the surface to be decorated as a consequence of the contact of the printing roller. This methodology, however, allows the printing and decorating of surfaces of limited dimensions, dictated principally by the extent and overall dimensions of the printing rollers, which have objective structural limits of construction.

A second methodology provides for the use, as an alternative to printing rollers, of silicone supports in plate form, substantially flat and mounted on respective frames. These make it possible to print and decorate surfaces which are also larger than those obtainable with conventional roller printing. Such supports, however, have the drawback of excessive elasticity in directions substantially parallel to the printing plane, which involves undesirable elongation of the support, with the result that smudging of the distributed colours is caused, which compromises their final quality. This has proved even more obvious in so-called multi-channel printing, in which several colours are superimposed on the printing surface.

Similarly to the flat plate form, the behaviour of a closed tape in ring form, and therefore endless, which rotates on driven cylinders may be considered.

The problem underlying the present invention is that of providing a support for the decorative printing of surfaces, structurally and functionally designed to remedy the drawbacks mentioned with reference to the prior art cited. Description of the invention This problem is solved by the invention by means of a support for the decorative printing of surfaces which is produced in accordance with the following claims. Brief description of the drawings The characteristics and advantages of the invention will become clear from the detailed description of one of its preferred exemplary embodiments illustrated by way of non- limiting example with reference to the appended drawings, in which: Figure 1 is a diagrammatic view in section and on an enlarged scale of a plate-like printing support according to the present invention,

Figure 2 is a diagrammatic partial plan view from above of the support in Figure 1, Figure 3 is a view corresponding to Figure 1 of a first alternative embodiment of the plate-like support of the invention,

Figure 4 is a view corresponding to Figure 1 of a second alternative embodiment of the plate-like support of the invention,

Figures 5 and 6 are views corresponding to Figure 1 of further alternative embodiments of the support according to the invention,

Figures 7 and 8 are diagrammatic views corresponding respectively to Figures 1 and 5 illustrating the support according to the invention in the presence of a discontinuous surface to be printed. Best modes for carrying out the inventions With reference to the drawings mentioned, 1 indicates as a whole a support for the decorative printing of a surface 2 according to the present invention.

The support 1 has a plate-like structure having a thickness indicated by S comprised between opposed faces 3 and 4 and is produced with a silicone matrix. On the surface of the face 3 are provided, for example by means of laser technology, a plurality of impressions, all indicated by 5, constituting seats for receiving one or more colouring substances with which the surface 2 is decorated. For this reason the face 3 will also be indicated in the following description as the printing face.

Owing to the distinct water-repellent characteristics of the silicone, the colouring substance, typically a water- based ink or similar pigment, is easily transferred onto the surface 2 by flowing from the impressions 5, without any problem of formation of deposits or layers of colorant within the impressions .

According to a principal characteristic of the invention, the support 1 comprises a reinforcing armature 6 embedded within the thickness S in the plate-like silicone structure .

The armature 6 is formed by a network of glass fibres 7 distributed in a random so-called "MAT" configuration, or without any preferential orientation in predetermined directions, as illustrated in Figure 2.

More particularly, the armature 6 is disposed within the thickness S of the plate-like support on the opposite side from the printing face 3. The glass-fibre reinforcement 6 is such as to impart to the plate-like support, characteristics of distinct rigidity (and consequently limited elasticity) in directions parallel to the plane of the plate-like support. At the same time, the armature 6 does not confer rigidity in a direction perpendicular to the plane of the support, indicated by the axis X in Figure 1, along which adequate elasticity is ensured owing to the silicone matrix (or even silicone foam matrix) having the thickness S. The plate-like support 1 may be fixed at the perimeter on a frame 8, only partially illustrated in Figure 2, through which it is handled during the operations of printing the surface 2.

To this end, prior to the printing step, the colouring substance is distributed in the impressions 5 according to a preselected configuration correlated to the decorative figure to be obtained on the surface 2. The printing face is then brought into contact with the surface 2 with consequent distribution of the colorant. It should be noted that owing to the elasticity conferred by the silicone in a direction perpendicular to the plane of the printing support, contact between the surfaces 2 and 3, during printing, takes place without the occurrence of localised overloads due to non- uniform bearing of the support on the surface to be decorated. This proves particularly advantageous in the presence of specific materials, such as, for example, ceramic materials or the like.

On the other hand, as a result of the rigidity conferred by the reinforcement with glass fibres in directions contained within the plane of the support, deformations in said directions are prevented or at most extremely limited within very narrow tolerances, imparting dimensional stability to the support itself . This makes it possible also to limit within said tolerances the dimensions of the decorative figures printed, and this proves advantageous for example in multi-channel printing, where several colours are printed in succession, superimposed one upon the other. Such rigidity conferred in the plane of the support thus makes it possible to observe predetermined dimensional tolerances, preventing smudging at the outlines of the decorative figures printed due to undesirable elongation of the support itself.

Owing, then, to the provision of the armature of glass fibre in random arrangement without any preferential orientation, any breakage of one or more fibres, due for example to the formation of the holes or the impressions for distribution of the colour, is not such as to compromise the stability and overall rigidity of the plate-like structure of the support .

It should further be noted that the armature embedded in the plate-like support may be produced with reinforcing fibres of a different chemical nature, although the choice of glass fibres represents a preferred choice, owing to the compatibility between the silicone matrix, with which the printing support 1 is produced, and silica, the basic component of the glass fibres. It should be noted that the armature may also be produced with fibres disposed substantially regularly, as long as they ensure dimensional stability.

In an alternative embodiment of the invention, shown diagrammatically in Figure 3, provision is made for the support 1 to be formed from an open porosity silicone foam having characteristics of permeability and porosity to air and vapour but not directly to water. Such a structure makes it possible to subject the plate-like support to one or more jets of compressed air directed onto the face 4 opposed to the printing face, with consequent squeezing of the impressions 5 to obtain the outflow of the colouring substance and also its transfer onto the surface to be decorated. Such printing methodology is usable precisely owing to the porosity of the silicone material which facilitates the pressure action of the compressed air through the thickness S to obtain the discharge of the impressions and pits filled with colorant.

A second alternative embodiment of the invention, shown diagrammatically in Figure 4, differs from the example in Figure 3 in that it further comprises a non-porous silicone layer 9 at the face 3, which layer is perforated to form the impressions 5 constituting seats for the printing ink. Said alternative form allows the compressed air which passes through the porous layer to emerge only through the impressions (5) , expelling the ink deposited therein.

In a further variant of the invention, proposed with reference to Figures 5 to 8, provision is made for the porosity in the porous silicone layer to be obtained by processing the same with formation of a plurality of blind holes 50 which involve said layer, and are preferably obtained by laser perforation. A suitably calibrated laser beam is guided substantially perpendicularly to the surface of the face 4 (opposed to the printing surface) such as to provide a dense network of parallel and non-intersecting holes, having a mean diameter of 0.2 - 2 mm and with a mean distance between centres of 0.4 - 2.5 mm.

In the example of Figure 5 the aforesaid holes are interrupted at a distance from the cavities of the impressions 5, rendering the support suitable for contact printing, as already indicated previously. In the example of Figure 6, on the other hand, the holes communicate with the printing surface through one or more capillary holes 51 which start from the bottom of the blind holes 50. The capillary holes 51 are also preferably produced by laser perforation, in a manner analogous to that of the execution of the holes 50.

With the porosity provided by means of the holes 50 the further advantage is obtained of improved flexibility of the support 1 in a direction perpendicular to the printing surface, facilitating the absorption of superficial roughness and/or irregularities of the surface to be printed, by means of localised deformation of the support almost exclusively in the perpendicular direction indicated above, or without substantial deformation in directions parallel to the printing surface. This is indicated with reference to Figures 7 and 8, in which it can be seen that the support of Figure 8, relative to that of Figure 7, permits better adherence to superficial roughness and unevenness of the surface to be printed 2 owing to the improved deformability conferred by the blind holes 50.

Preferably, the silicone-based elastomer with which the support 1 is produced (case of single-layer support) or at least one of the layers thereof (case of multi-layer support) is modified by the addition of reactive and/or interpolant groups and/or of fillers having a chemical base of Si0₂ - SiCH₃ - SiOH.

The invention thus solves the problem posed, by providing numerous advantages with respect to the known solutions.

A first advantage lies in the fact that printing supports according to the invention allow the decorative printing of surfaces much larger than those obtainable with conventional printing rollers, guaranteeing, however, dimensional stability within the typically accepted tolerances .

A second advantage lies in the fact that the relative rigidity of the support in directions parallel to the plane of the support itself guarantees optimum superimposition of the colours distributed, in particular in multi-channel printing, devoid of smudging even in the case of large dimensions of the surface to be printed.

A further advantage is that the high degree of rigidity in the plane of the support does not prejudice the characteristics of elasticity of the support in a direction perpendicular to the plane itself for optimum bearing contact of the support on the surface to be printed.

A still further advantage lies in being able to use a porous printing means, which assists the expulsion of the ink through compressed air which filters through the porosity, to the point of no longer making contact between the printing means and the surface to be printed necessary.

Claims

1. A support for the decorative printing of surfaces (2) , having a plate-like silicone structure on one face (3) of which is distributed a colouring substance to be transferred onto said surface (2) , characterised in that it comprises a reinforcing armature (6) at least partially embedded in the plate-like structure.

2. A support according to claim 1, wherein said armature (6) comprises a plurality of fibres (7) embedded in the silicone structure.

3. A support according to claim 1 or 2 , wherein the fibres (7) of said armature (6) are glass fibres distributed in a MAT configuration, without any prevalent orientation in predetermined directions.

4. A support according to claim 2 or 3 , wherein said armature (6) with fibres (7) is disposed within the thickness (S) of said plate-like structure on the opposite side from the printing face (3) .

5. A support according to one or more of the preceding claims, wherein the surface of the printing face (3) comprises a plurality of impressions (5) adapted to receive the colouring substance distributed thereon in order to transfer it onto the surface to be decorated (2) .

6. A support according to one or more of claims 1 to 5, wherein the silicone of said plate-like structure has characteristics of porosity to air such that the action of a jet of compressed air directed onto the plate-like structure, on the opposite side from the printing face (3) , effects the squeezing of said impressions (5) with the emptying of the latter and consequent transfer of the colouring substance onto the surface to be decorated (2) .

7. A support according to claim 6, further comprising a layer (9) of non-porous silicone at the printing face (3) , said impressions (5) being formed by perforation of said layer (9), such that the compressed air, once it has passed through the porous layer, can emerge to the outside exclusively through the impressions (5) , taking with it the colouring substance deposited therein.

8. A support according to one or more of the preceding claims, comprising, on the opposite side from the printing surface (3) , a plurality of blind holes (50) , interrupted at a predetermined distance from said printing surface.

9. A support according to claim 8, wherein said holes (50) extend perpendicularly to the printing surface (3) and are obtained by laser perforation.

10. A support according to claim 8 or 9, wherein each of said holes (50) communicates with the printing surface (3) through one or more capillary holes (51) .

11. A support according to claim 10, wherein said capillary holes (51) are obtained by laser perforation.

12. A support according to one or more of the preceding claims, produced from silicone-based elastomer with the addition of reactive and/or interpolant groups and/or of fillers having a chemical base of Si0₂-SiCH₃-SiOH.