阅读说明：本技术 用于陶瓷制品的表面装饰的方法和机器 (Method and machine for the surface decoration of ceramic products ) 是由 斯特凡诺·斯卡尔多维 克拉迪奥·里奇 安德里亚·布雷夏尼 于 2018-05-16 设计创作，主要内容包括：用于基础制品(3)的表面装饰的方法和机器(2),所述基础制品包括陶瓷材料并具有表面(4)；印刷组件(16)将粘合材料(17)以数字方式并选择性地施加到表面(4)的限定区域(18)上；处理组件(20)将粉末材料(21)以数字方式并选择性地沉积在限定区域(18)中；并且布置在基础制品(3)上的过量的粉末材料(21)被移除。(Method and machine (2) for surface decoration of a base article (3) comprising a ceramic material and having a surface (4); a printing assembly (16) digitally and selectively applies an adhesive material (17) onto defined areas (18) of the surface (4); a processing assembly (20) digitally and selectively depositing powder material (21) in the defined area (18); and the excess powder material (21) arranged on the base product (3) is removed.)

1. A method for the surface decoration of a base article (3) comprising a ceramic material and having at least one surface (4), the method comprising:

a conveying step during which the base article (3) is conveyed along a given path (P) through an application station (13), a work station (14) arranged downstream of the application station (13), and a removal station (15) arranged downstream of the work station (14);

an application step during which a printing assembly (16) arranged at the application station (13) selectively applies an adhesive material (17) in at least one defined region (18) of the surface, so that at least another region (19) of the surface (4) different from the defined region (18) is left free of the adhesive material (17);

a deposition step during which a processing assembly (20) arranged in the workstation (14) selectively deposits the powder material (21) on the binding material (17) in a defined area (18) of the surface (4) so as not to cover at least a portion of the further area (19) of the surface (4) itself; and

a removal step during which excess powder material (21) arranged on the base article (3), in particular powder material not bonded to the binding material, is removed in the removal station (15);

the base articles (3) are conveyed through the work station (14) in an advancing direction (A);

the processing assembly (20) comprises:

at least one container (26) suitable for containing said powder material (21) and having an outlet mouth (27) with a longitudinal extension transversal (in particular perpendicular) to said advancing direction (a);

a plurality of dispensing members (28) arranged in series along the outlet mouth (27);

a plurality of actuators (29), each of which moves a respective dispensing member (28) between a closed position, in which the respective dispensing member (28) blocks the passage of the powder material (21) through the region of the outlet mouth (27) in which it is arranged, and an open position, in which the respective dispensing member (28) allows the passage of the powder material (21) through the region of the outlet mouth (27) in which it is arranged.

2. Method according to claim 1, wherein during the deposition step the handling assembly (20) selectively deposits a first type of said powdered material (21) in a first portion of the defined area (18) and a second type of said powdered material (21) in a second portion of the defined area (18) different from the first portion of the defined area (18) itself.

3. The method according to claim 2, wherein the processing assembly (20) selectively deposits the first type of powder material (21) in a first portion of the defined area (18) and not in a second portion of the defined area (18) itself;

the handling assembly (20) selectively deposits the second type of powder material (21) in a second portion of the defined area (18) instead of in a first portion of the defined area (18) itself.

4. The method according to claim 1 or 2, wherein the processing assembly (20) deposits a first type of the powder material (21) in at least a first portion of the defined area (18);

the processing assembly (20) deposits the powder material (21) of a second type in at least a first portion of the defined area (18).

5. The method according to any one of claims 2 to 4, wherein the first type of powder material (21) and the second type of powder material (21) are different in color from each other;

a conveying device (12) conveys the base articles (3) along the given path (P) through the application station (13), the work station (14) and the removal station (15).

6. The method according to any one of the preceding claims, wherein the powder material (21) comprises a ceramic material;

in particular, the powder material comprises particles having a size ranging from 50 μm to 500 μm.

7. The method according to any one of the preceding claims, wherein, during the application step, the printing assembly (16) applies the adhesive material (17) by ejecting at least one jet of the adhesive material (17);

during the removal step, excess of the powder material (21) (in particular, the powder material not bonded to the binding material) is removed by suction;

in particular, the printing assembly (16) comprises an inkjet head which ejects one or more jets of the adhesive material (17) onto the surface (4).

8. The method according to any one of the preceding claims, wherein, during the application step, the printing assembly (16) applies the adhesive material (17) digitally onto the surface (4) so as to reproduce a defined pattern on the surface (4) itself;

during the deposition step, the processing assembly (20) digitally deposits the powder material (21) so as to reproduce another defined pattern on the surface (4);

in particular, the pattern and the further defined pattern coincide.

9. The method according to any one of the preceding claims, wherein the adhesive material (17) is selected from the group consisting of:

a substantially stable material (in particular, a substantially stable composition) that does not significantly change the properties of the material when in contact with air and at temperatures between at least 15 ℃ and 60 ℃;

a thermoplastic material (in particular, a thermoplastic composition) which hardens at room temperature;

a composition having at least one component capable of being absorbed by the base article (3);

a curable material (curable composition) which hardens upon contact with a hardener present in the powder material (21); and

a combination of the substantially stable material, the thermoplastic material, the composition, and the curable material;

with the provisos that: in case the binding material (17) comprises a curable composition, in particular the binding material is a curable composition, the powder material (21) comprises a hardener for the curable composition.

10. The method according to any one of the preceding claims, wherein the adhesive material (17) comprises a substantially stable material (in particular, the substantially stable composition), in particular the adhesive material being the substantially stable material, which does not significantly change the properties of the material when in contact with air and at a temperature of between at least 15 ℃ and 60 ℃.

11. The method according to any one of the preceding claims, wherein the bonding material comprises a thermoplastic material (in particular, the composition), in particular the bonding material is the thermoplastic material, which hardens at room temperature.

12. The method according to any one of the preceding claims, wherein the adhesive material comprises a composition, in particular the adhesive material is the composition, which has at least one component that is absorbable by the base article (3).

13. Method according to any one of the preceding claims, wherein the binding material comprises a curable composition, in particular the binding material is the curable material, which hardens upon contact with a hardener present in the powder material (21).

14. A machine for the surface decoration of a base article (3) comprising a ceramic material and having at least one surface (4), said machine (2) comprising:

a conveying device (12), said conveying device (12) being intended to convey said base articles (3) along a given path (P) through an application station (13), a work station (14) arranged downstream of said application station (13), and a removal station (15) arranged downstream of said work station (14);

a printing group (16) arranged at the application station (13) and adapted to selectively apply adhesive material (17) in at least one defined region (18) of the surface (4) so that at least another region (19) of the surface (4) different from the defined region (18) is left free of adhesive material (17);

-a handling assembly (20) arranged at said workstation (14) and adapted to selectively deposit a powder material (21) at a defined area (18) of said surface (4) so as not to cover at least a portion of said further area (19) of said surface (4) itself; and

a removal device (22) arranged at the removal station (15) and adapted to remove excess of the powder material (21) (in particular powder material not bonded to the binding material) present on the base article (3);

said conveying means (12) being adapted to convey said base articles (3) through said work station (14) in an advancing direction (A);

the processing assembly (20) comprises:

at least one container (26) suitable for containing said powder material (21) and having an outlet mouth (27) with a longitudinal extension transversal (in particular perpendicular) to said advancing direction (a);

a plurality of dispensing members (28) arranged in series along the outlet mouth (27);

a plurality of actuators (29), each of which is adapted to move a respective dispensing member (28) between a closed position, in which the respective dispensing member (28) blocks the passage of the powder material (21) through the region of the outlet mouth (27) in which it is arranged, and an open position, in which the respective dispensing member (28) allows the passage of the powder material (21) through the region of the outlet mouth (27) in which it is arranged.

15. The machine of claim 14, wherein the processing assembly (20) comprises:

-first deposition means (23) adapted to selectively deposit a first type of said powdered material (21) in a first portion of said defined area (18); and

at least a second deposition device (24), said at least second deposition device (24) being adapted to selectively deposit a second type of said powder material (21) in a second portion of said defined area (18), said second portion of said defined area (18) being different from said first portion of said defined area (18);

in particular, said first deposition device (23) and said second deposition device (24) each comprise at least a respective said container (26), a respective plurality of said dispensing members (28) (fingers), and a respective plurality of said actuators (29).

16. Machine according to claim 14 or 15, wherein the printing assembly (16) comprises at least one inkjet head adapted to eject one or more jets of adhesive material (17) onto the surface (4).

17. The machine of any one of claims 14 to 16, wherein the removal device (22) comprises a suction unit (22') for sucking excess powder material (21), in particular the powder material not bonded to the binding material.

18. The machine according to any one of claims 14 to 17, wherein the printing assembly (16) comprises at least two application devices (30) which are independent of each other and each of which is adapted to eject one or more respective jets of adhesive material (17) onto the surface (4);

in particular, each application device (30) comprises at least one respective ink-jet head.

19. The machine according to any one of claims 14 to 18, further comprising a control unit (25) adapted to control the printing assembly (16) in a digital manner, so that the printing assembly (16) itself applies the adhesive material (17) so as to reproduce a defined pattern on the surface (4);

-the control unit (25) is adapted to digitally control the handling assembly (20) so that the handling assembly (20) itself deposits the powder material (21) so as to reproduce another defined pattern on the surface (4) itself;

in particular, the pattern and the further defined pattern coincide.

20. An apparatus for producing ceramic articles (T), said apparatus (1) comprising:

decorating machine (2) according to any one of claims 14 to 19;

a compacting machine (5) for compacting a powder material (CP) comprising ceramic powder so as to obtain a compacted powder layer (KP);

-a conveying assembly (6) comprising said conveying means (12) and adapted to feed said powder material (CP) to said compacting machine (5) along said given path (P), and from which compacting machine (5) said layer of compacted powder (KP) is conveyed to said decorating machine (2);

the base article (3) comprises at least a portion of the compacted powder layer (KP).

Technical Field

The present invention relates to a method and a machine for the surface decoration of a base product comprising a ceramic material. Furthermore, the present invention relates to a method and a system for manufacturing ceramic articles.

Background

Machines in the field of manufacturing ceramic products (in particular slabs; more particularly tiles) for the surface decoration of base products are known.

In detail, a machine is known which comprises a printing assembly adapted to selectively apply adhesive material in defined areas of the surface of the article, so as to create a pattern on the article itself. The machine is also provided with a deposition device which deposits the powdered material over the entire surface. The powder material deposited in the defined area remains attached to the binding material, wherein powder material arranged in other areas of the surface is removed.

This type of machine has several drawbacks, including the following.

The use of powder materials is excessive. This may result in significant waste of material or require complex and expensive technical measures to recycle the material in large quantities. The recirculation system is prone to wear.

Recovery of the powder material can also cause particle size changes or possible clustering due to glue traces.

The use of different material combinations is only possible by installing various machines on the production line.

Moreover, with these types of machines, it is practically impossible, or though still extremely complex and expensive, to obtain differences in different colors (e.g. grey scales).

Also known is a machine for surface decoration comprising a treatment assembly which deposits a powdered material directly (without prior application of glue) onto a defined area of the surface of an article, so as to create a pattern on the article itself

However, these machines are not without drawbacks, including the following. Unfortunately, currently available processing assemblies are not capable of producing patterns with exceptionally high resolution. Furthermore, the resulting pattern is imprecise and has defects and inconsistencies with respect to the desired pattern.

EP2892657 describes a method and a machine for the digital decoration of products with granular material.

The object of the present invention is to provide a method and a machine for the surface decoration of base articles comprising ceramic material, and a method and an apparatus for the production of ceramic articles, which allow to overcome at least partially the drawbacks of the prior art, and which are both cheap and easy to manufacture.

Disclosure of Invention

According to the present invention, there is provided a method and a machine for the surface decoration of a base article comprising ceramic material, and an apparatus for manufacturing ceramic articles according to what is set forth in the following independent claims, and preferably according to any one of the claims depending directly or indirectly on said independent claims.

Drawings

The invention is described below with reference to the accompanying drawings, which show some non-limiting embodiments, in which:

figure 1 is a schematic side view of an apparatus according to the invention;

FIG. 2 is a schematic perspective view of a detail of the apparatus of FIG. 1;

FIG. 3 is a side cross-sectional view of a detail in FIG. 2;

FIGS. 4 to 7 are schematic side views of successive operating steps of a part of the apparatus in FIG. 1;

FIGS. 8-11 are schematic side views of successive operational steps of a portion of the different embodiments shown in FIGS. 4-7;

FIGS. 12a) -d) are side views of the base article during the various steps shown in FIGS. 4-7;

FIGS. 13a) -d) are plan views of the base article shown in FIGS. 12a) -d), respectively; and

fig. 14 is a schematic side view of a different embodiment of a portion of the apparatus of fig. 4-7.

Detailed Description

The plant for producing ceramic products T is indicated as a whole by the reference numeral 1 in figure 1. In particular, the ceramic product T is a slab (more precisely a tile).

The apparatus 1 comprises: machine 2 for the surface decoration of a base article 3, said base article 3 comprising a ceramic material and having at least one surface 4; a compacting machine 5 for compacting a powder material CP comprising ceramic powder, so as to obtain a compacted powder layer KP; and a conveyor assembly 6, said conveyor assembly 6 being adapted to feed (in a substantially continuous manner) the powder material CP along a given path P from the inlet station 7 to the compactor 5, and to feed the compacted powder layer KP from the compactor 5 to the decorating machine 2 (and to the outlet station 8). In particular, compactor 5 and machine 2 are arranged along path P between inlet station 7 and outlet station 8. More specifically, machine 2 is arranged downstream of compactor 5.

In particular, the base article 3 comprises (at least) a portion of the compacted powder layer KP.

According to some non-limiting embodiments, the apparatus 1 comprises at least one cutting assembly 9 for cutting the compacted powder layer KP transversely so as to obtain a base article 3 having a portion of the compacted powder layer KP. In particular, the cutting assembly 9 is arranged along the path P (more specifically, downstream of the compacting machine 5 and upstream of the machine 2). Advantageously, but not necessarily, the delivery assembly 6 is adapted to feed the compacted powder layer KP to the cutting assembly 9 and to deliver the base article 3 (by means of the machine 2) downstream of the cutting assembly 9.

According to some non-limiting embodiments, the plant 1 further comprises a dryer 10, said dryer 10 being arranged along the path P downstream of the compactor 5 (more specifically downstream of the cutting assembly 9) and upstream of the machine 2.

According to some non-limiting embodiments, the plant 1 further comprises a firing kiln 11, said firing kiln 11 being used for sintering the base product 3 (sintering the compacted powder layer KP) in order to obtain the ceramic product T. In particular, firing kiln 11 is arranged along a given path P downstream of machine 2 (and downstream of removal station 15, said removal station 15 being described in further detail below).

According to some non-limiting and non-illustrated embodiments, the plant 1 does not comprise a compacting machine 5 and a cutting assembly 9, but a conventional compacting machine (of known type) for ceramic tiles. Typically, such pressing machines are provided with a vertical axis hydraulic pressing device adapted to press the ceramic material into a powder so as to directly obtain a single slab of pressed material (which does not require cutting).

The machine 2 comprises a conveying device 12 (which conveying device 12 is in particular part of the conveying assembly 6) for conveying (by substantially continuous movement) the base articles 3 along a given path P through an application station 13 and a work station 14 (said work station 14 being arranged downstream of the application station 13). According to some embodiments, the conveying device 12 is also adapted to convey the base articles 3 through a removal station 15 (in particular, said removal station 15 is arranged along the path P downstream of the work station 14).

The machine 2 further comprises a printing assembly 16, which printing assembly 16 is arranged in the application station 13 and is adapted to apply (digitally) an adhesive material 17 (see, for example, fig. 5, 9, 12 and 13) to the surface 4. In particular, the printing assembly 16 is adapted to selectively apply the adhesive material 17 at least in a defined area 18 of the surface 4, so that at least another area 19 of the surface 4 (in particular, different from the defined area 18) is left free of the adhesive material 17.

The machine 2 further comprises a handling assembly 20, said handling assembly 20 being arranged in the workstation 14 and being adapted to selectively (digitally) deposit a powder material 21 (in particular, on the binding material 17) in a defined area 18 of the surface 4 so as not to cover at least a portion of another area 19 of the surface 4.

The fact that the binding material 17 (the binding material 17 in particular need not be sticky and serves to help retain at least a portion of the powder material 21 on the base article 3) and the powder material 21 are present on the surface 4 at the same time makes it possible to reduce the risk of the powder material 21 moving on the base article 3. This advantage is particularly evident when the powder material 21 is deposited on the binding material 17 already present on the surface 4.

According to some non-limiting embodiments (see fig. 1-11), the machine 2 comprises a removal device 22, said removal device 22 being arranged in the removal station 15 and being adapted to remove the excess powder material 21 (in other words, the powder material not bonded to the binding material) present on the base article 3.

In particular, the powder material comprises (more precisely consists of) a ceramic material.

According to some non-limiting embodiments, the powder material comprises (more specifically, consists of) particles having a size ranging from 50 μm to 500 μm (more precisely, from 100 μm to 500 μm).

The size of the particles is obtained by continuous sieving using a sieve with holes of decreasing size (diameter). The diameter of the apertures of the first screen that do not allow the particles to pass through represents the size (or more precisely the diameter) of the particles.

The measurements made by successive sieving are carried out until the size (or rather the diameter) of the granules and the holes of the sieve allow (in particular to a minimum of 0.05 mm).

Advantageously, but not necessarily, the printing assembly 16 comprises at least one inkjet head (inkjet-known per se and not shown) suitable for ejecting one or more jets of adhesive material towards the surface 4. For example, the printing member 16 is as described in patent application EP 703863. In particular, in some particular cases, the inkjet head is a piezoelectric inkjet head; such as dimatixstartfire^TMSG1024 (made of)Manufacture) or1003 GS40。

Advantageously, but not necessarily, the removal device 22 comprises a suction unit 22 ', said suction unit 22' being intended to suck excess (in other words, not bonded to the surface 4 by the bonding material 17) of the powder material 21. More precisely, the suction unit 22' is configured such that, in use, the powder material 21 is removed by suction upwards. In particular, the suction unit 22' comprises a suction mouth facing downwards.

Suction allows (e.g., as opposed to blowing) to reduce the risk of the powder material 21 reaching undesired areas of the surface 4.

According to some non-limiting embodiments (see fig. 8-11), the processing assembly 20 includes a deposition device 23 and at least one deposition device 24. In particular, the deposition means 23 are adapted to (selectively) deposit a first type of powdered material 21 (of the type indicated by small-size dots in fig. 8 to 11) in a first portion of the delimited area 18; the deposition means 24 are adapted to deposit a second type of powdered material (which is different from the first type of powdered material and is indicated in fig. 8-11 by a larger dot than the first type of dot) in a second portion of the defined area 18, which is different from the first portion of the defined area 18.

More precisely, in some cases, the deposition means 23 are adapted to selectively deposit the first type of powdered material 21 in a first portion of the defined area 18 instead of in a second portion of the defined area 18; the second deposition means 24 are adapted to selectively deposit the second type of powdered material 21 in the second portion of the defined area 18 instead of in the first portion.

In particular, the first and second types of powder material 21 differ from each other in their mechanical/physical properties and/or color.

According to a particular non-limiting embodiment (such as the one shown in fig. 2 and 3), the processing assembly 20 (more precisely, each deposition device 23 and 24) has a front surface 33 in which the powdered material 21 is discharged.

In an embodiment, as shown in fig. 8-11, the front surfaces 33 of the deposition devices 23 and 24 face each other (in opposite directions). In this way, the time between two applications of the powder material 21 is reduced

According to the embodiment shown in fig. 14, the front surfaces 33 of the deposition devices 23 and 24 face in the same direction (specifically, in the advancing direction a).

By having two (or more) deposition devices 23 and 24, a combination of two (or more) types of powder material 21 can be obtained on the surface 4 in a relatively simple manner. In this way, special aesthetic effects may be created, such as combinations of different colors and/or different shades (e.g., different gray differences).

In this regard, it is noted that the first and second types of powder material 21 may be deposited in the same portion of the defined area 18 (in varying amounts), alternatively or in addition to that described above. In this way, for example, shades of different colors can be obtained.

According to some non-limiting and non-illustrated embodiments, the removal device 22 comprises a further suction unit arranged between the deposition devices 23 and 24.

According to some non-limiting and non-illustrated embodiments, machine 2 comprises, in succession, in advancing direction a and along path P, a printing assembly 16 (provided with application device 30), a treatment assembly 20 (provided with deposition device 23), a removal device 22, another printing assembly (substantially identical to printing assembly 16), another treatment assembly (substantially identical to treatment assembly 20), and another removal device (substantially identical to removal device 22).

Advantageously, but not necessarily, the machine 2 also comprises a control unit 25 (shown in fig. 4), the control unit 25 being adapted to control the printing assembly 16 (digitally) so that the printing assembly 16 itself applies the adhesive material 17 in order to reproduce the pattern defined on the surface 4. The control unit 25 is adapted to control the processing assembly 20 (digitally) so that the processing assembly 20 itself deposits the powder material 21 in order to reproduce another pattern defined on the surface 4 itself.

In particular, the pattern and the further pattern are stored in the control unit.

Advantageously, but not necessarily (e.g. as shown in fig. 13c) and 12 c)), said pattern and said further pattern coincide. In these cases, the distribution of the powder material 21 on the surface 4 may appear to be greater than the distribution of the binding material 17 on the surface 4, since the handling component 20 is less precise than the printing component 16 and, in use, the powder material 21 is advantageously deposited in an amount slightly excessive with respect to the amount required (in order to reduce the risk of regions in which the powder material 21 is beneficial being left without the desired amount).

In particular, the conveying means 12 are adapted to convey the base articles 3 in an advancement direction a through the work station 14.

According to some non-limiting embodiments (fig. 2 and 3), the processing assembly 20 (more precisely, each deposition device 23 and 24) comprises: at least one container 26 (in particular, a hopper), the at least one container 26 being adapted to contain the powder material 21 and having an outlet mouth 27, the longitudinal extension of the outlet mouth 27 being transverse (in particular, perpendicular) to the advancement direction a; a plurality of dispensing members 28 (fingers) (only one of which is shown in fig. 2 and 3), which plurality of dispensing members 28 is arranged in series along the outlet mouth 27 (so as to close the outlet mouth 27 itself); and a plurality of actuators 29, each of which is adapted to move a respective dispensing member 28 (independently of the other dispensing members 13) between a closed position, in which the respective dispensing member 28 blocks the passage of the powder material 21 through the region of the outlet mouth 27 in which it is arranged, and an open position, in which the respective dispensing member 28 allows the passage of the powder material 21 through the region of the outlet mouth 27 in which it is arranged.

According to some non-limiting embodiments, the processing component 20 is as described in patent application WO2009118611 (by the same applicant) and/or in patent IT 1314623.

According to some non-limiting embodiments (fig. 8-11), the printing assembly 16 comprises at least two application devices 30, the at least two application devices 30 being independent of each other, and each of said at least two application devices 30 being adapted to eject one or more jets of adhesive material 17 onto said surface 4. In particular, each application device 30 comprises at least a respective ink-jet head.

The presence of two application devices 30 allows the movement of the base articles 3 to be accelerated along the path P and therefore increases the productivity/efficiency of the machine 2 (and/or of the apparatus 1).

In the embodiment shown in fig. 8-11, the application device 30 is arranged upstream of the deposition devices 23 and 24. According to some non-limiting and non-illustrated embodiments, one of the two application devices 30 is arranged between the deposition devices 23 and 24 and applies the bonding material 17 on which the second type of powder material 21 is deposited onto the surface 4.

According to some non-limiting embodiments (e.g., the embodiment shown in fig. 1), the cutting assembly 9 comprises: a cutting blade 31, the cutting blade 31 being adapted to contact the compacted ceramic powder layer KP to cut the compacted ceramic powder layer KP; and a processing unit (known per se and not shown) for moving cutting blade 31 to direction a along a transverse trajectory, more precisely a diagonal. In this way, it is possible to provide the basic article 3 with an end edge substantially perpendicular to the direction a, while advancing the layer KP of compacted ceramic powder in a continuous movement.

Advantageously, but not necessarily, the cutting assembly 9 also comprises two further blades 32, which two further blades 32 are arranged on opposite sides of the path P and are adapted to cut the layer KP of compacted ceramic powder and define lateral edges of the base article 3 that are substantially perpendicular to the end edges (and substantially parallel to the direction a). In some particular cases, the cutting assembly 9 is similar to the one described in patent application publication No. EP 1415780.

According to another aspect of the invention, there is also provided a method for surface decoration of a base article 3 comprising a ceramic material and having at least a surface 4.

Advantageously, but not necessarily, the method is carried out by the machine 2 described above.

The method comprises the following steps: a conveying step during which the base articles 3 are conveyed along a given path P through an application station 13 and a work station 14 (arranged downstream of the application station); an application step during which a printing assembly 16 arranged in the application station 13 applies (digitally) an adhesive material 17 to the surface 4; a deposition step (which is at least partially subsequent to the application step) during which a processing assembly 20 arranged in the workstation 14 (in particular, as defined above) selectively deposits (digitally) a powder material 21 (deposited onto the binding material 17) in a defined area 18 of the surface 4, so as not to cover at least a portion of another area 19 of the surface 4 itself (said other area 19 being different from the defined area 18).

In particular, during the conveying step, the conveying means 12 (in particular, as defined above) convey the base articles 3 along a given path P through the application station 13, the work station 14 and the removal station 15.

Advantageously, but not necessarily, during the deposition step, the processing assembly 20 deposits a slight excess of the powdered material 21 with respect to the quantity effectively required.

According to some non-limiting embodiments, the binding material (in particular, the binding material need not be adhesive and is used to help retain at least a portion of the powder material 21 on the base article 3) comprises (more precisely, consists of) a mixture comprising (or consisting of) glycols (such as DEG or PEG), esters (e.g. fatty acid esters), acetates (e.g. methyl or ethyl acetate), vinyl acetates, polyols (such as polyvinyl alcohol), and the like.

Additionally or alternatively, according to some non-limiting embodiments, the adhesive material is selected from the group consisting of: a substantially stable material (in particular, a composition) which does not significantly change its properties upon contact with air and at temperatures of between at least 15 ℃ and 60 ℃; a thermoplastic material (in particular, a composition) which is hardenable at room temperature; a composition having at least one component absorbable by the base article 3; a curable material (composition) adapted to harden upon contact with a hardener (present in the powder material 21); and combinations thereof. In particular, the adhesive material is selected from the group consisting of: thermoplastic materials (particularly compositions), curable materials, and combinations thereof.

In particular, the adhesive material (more precisely, the substantially stable material) is for example not significantly evaporated (after being applied to the base article 3-between the application step and the deposition step).

If the bonding material comprises, in particular, a curable composition, the powder material 21 comprises a hardener (e.g. a peroxide) for the curable composition.

Advantageously, but not necessarily, the adhesive material is suitable to be applied by means of an ink-jet head (piezoelectric).

Advantageously, but not necessarily, the adhesive material comprises in particular a substantially stable material (in particular a composition).

According to some advantageous non-limiting embodiments, the adhesive material (more precisely, the substantially stable material) is partially absorbed by the base article 3 (between the application step and the deposition step).

According to some non-limiting embodiments, the adhesive material comprises, in particular, a thermoplastic material (in particular, a composition).

According to some non-limiting embodiments, the adhesive material comprises, in particular, a composition having at least one component that can be absorbed by the base article 3.

According to some non-limiting embodiments, the adhesive material comprises, inter alia, a curable material (composition).

According to a particular non-limiting embodiment, the substantially stable material comprises a paraffinic oil or an esterified oil and an inorganic enamel ground and dispersed in these oils (in particular, the paraffinic oil or the esterified oil and the inorganic enamel composition). For example, the substantially stable material isSDS VIK M6.

According to a specific non-limiting example, the thermoplastic material is a hot-melt type material and comprises in particular a mixture of EVA (ethylene vinyl acetate), paraffin and styrene oligomers (Bergeron, V, Bonn, D., Martin, J.Y. and Vovelle, L. (Bergeron, V., Nature, 405, pp. 772-775 (2000); Progress and Trends in Le, H.P in Ink-jet printing Technology, J.ImSci.Tech., 42, pp. 49-62 (1998); Verschueren, M. A Difuse-Interface Model for construction in Flow, Ph D.D. the same, Eindindon University of Technology (1999)).

According to a specific non-limiting embodiment, the composition having at least one absorbable component comprises, in particular, polyvinyl alcohol (e.g., polyvinyl alcohol)Is/are as follows) And/or vinyl acetate (e.g. of the typeIs/are as followsLP BX 860) in aqueous or alcoholic solution.

According to a specific non-limiting embodiment, the curable composition comprises (inter alia) at least one unsaturated resin (more precisely, a mixture of unsaturated resins). In particular, the unsaturated resin is a polyester resin (having an acrylic group). In some non-limiting cases, the unsaturated resin includes a styryl group. The curable composition may be easy compositions^TM(Easy Composites Ltd, Unit 39Park Hall Business Village, Longton, Stoke on Trent. ST35XA; Web. www. Easy Composites. co. uk.) Water Clear Polyester Casting Resin (Water Clear Polyester Casting Resin).

According to some non-limiting and non-illustrated embodiments, during the application step, the printing assembly 16 applies the adhesive material 17 on the entire surface 4.

Advantageously, but not necessarily, during the application step, the printing assembly 16 selectively applies the adhesive material 17 in defined areas 18 of the surface 4, so that at least another area 19 of the surface 4 remains free of the adhesive material 17.

In particular, during the conveying step, the base articles 3 are conveyed along a given path P through a removal station 15 (arranged downstream of the work station). More specifically, the method also comprises a removal step (which is at least partially subsequent to the deposition step) during which the excess (in other words, not bonded to the binding material) powder material 21 arranged on the base article 3 is removed in the removal station 15.

Advantageously, but not necessarily, during the deposition step, the handling assembly 20 deposits (selectively) a first type of powdered material 21 in a first portion of the defined area 18 and deposits (selectively) a second type of powdered material 21 in a second portion of the defined area 18 that is different (at least in part) from the first portion of the defined area 18 itself.

According to some non-limiting embodiments, the processing assembly 20 deposits (selectively) a first type of powder material 21 in a first portion of the defined area 18, but not in a second portion of the defined area 18; the processing assembly 20 deposits (selectively) a second type of powder material 21 in a second portion of the defined area 21, instead of in the first portion.

According to some non-limiting embodiments, the processing assembly 20 (selectively) deposits a first type of powder material 21 in at least a first portion of the defined area 18; the processing assembly 20 (selectively) deposits a second type of powder material 21 in at least a first portion of the defined area 18. In these cases, in particular, a quantity 21 of the first type of powdered material to be deposited is included, which quantity is insufficient to cover the whole first portion of the delimited area 18. More precisely, the second type of powder material 21 adheres to the binding material 17 in an insufficient amount of the first type of powder material 21. In this way, for example, different shades of color and/or special aesthetic effects can be obtained.

In particular, the powder material comprises (consists of) a ceramic material.

In some cases, the powder material includes (more particularly, consists of) particles having a size ranging from 50 μm to 500 μm.

According to some non-limiting embodiments, during the application step, the printing assembly 16 applies the adhesive material 17 by spraying at least one jet of adhesive material 17 itself. In particular, the printing assembly 16 comprises an inkjet head which ejects one or more jets of adhesive material 17 towards the surface 4.

Advantageously, but not necessarily, during the removal step, the excess (not bonded to the binding material) of powder material 21 is removed by suction.

According to some non-limiting embodiments, during the application step, the printing assembly 16 applies the adhesive material 17 digitally onto the surface (in particular, the printing assembly is digitally controlled) so as to reproduce (by the control unit 25) a defined pattern on the surface 4; during the deposition step, the processing assembly 20 digitally deposits the powder material 21 (in particular, it is digitally controlled) in order to reproduce (by means of the control unit 25) another defined pattern on the surface.

In some cases, the pattern and the other pattern are identical.

The above-described method is illustrated in fig. 12 and 13 by way of example with particular reference to the processing performed on the base article 3. More precisely, fig. 12a) and 13a) show the base product 3 still to be treated; fig. 12b) and 13b) show the base article 3 on which the adhesive material 17 has been applied (after the application step); fig. 12c) and 13c) show (after the deposition step) the base article 3 on which the powder material 21 has been applied (it can be observed that the powder material 21 slightly overlaps the binder material 17); and fig. 12d) and 13d) show the base article 3 from which the excess powder material 21 has been removed (after the removal step).

The object of the present invention provides a number of advantages over the prior art. Which comprises the following steps: reducing waste of powder material and/or the amount to be recycled; reducing the risk of changing the particle size; the possibility of obtaining patterns with different colours and/or shades in a simple manner; the possibility of obtaining a quality pattern with good definition in a relatively uncomplicated manner.

The contents of the references (articles, books, patent applications, etc.) cited in this document are incorporated by reference in their entirety unless explicitly stated otherwise. In particular, said references are incorporated herein by reference.