Method and plant for manufacturing ceramic products

1. A method for manufacturing ceramic products comprising;

a feeding step to feed a mixture of at least two ceramic powders having different features and/or colours from one another so as to obtain a powder material strip;

a compacting step to compact the powder material strip so as to obtain a compacted powder layer provided with respective surface chromatic effects and with respective chromatic effects in the thickness;

a printing step to create a graphic decoration on the surface of the compacted powder layer so as to make the compacted powder layer more similar to a natural product;

the printing step comprises the further steps of:

acquiring a surface image of the compacted powder layer, which reproduces the respective surface chromatic effects;

processing said surface image so as to obtain the graphic decoration to be applied on the surface of the compacted powder layer, which is coordinated with the respective chromatic effects in the thickness; and

printing the graphic decoration on the surface of the compacted powder layer the method comprising the further steps of:

identifying a reference image of the surface image of the compacted powder layer within an archive, where a plurality of reference images are stored, each of the reference images reproducing given surface chromatic effects; and

processing the reference image so as to obtain the graphic decoration to be applied on the surface of the compacted powder layer,

wherein the step of identifying a reference image of the surface image of the compacted powder layer comprises the further steps of;

processing the surface image of the compacted powder layer so as to identify the trajectories of the most significant surface chromatic effects to be compared with the reference images contained in said archive; and

identifying, among the reference images contained in said archive, the one that is the most similar to the surface image of the compacted powder layer.

2. A method according to claim 1 , further comprising the step of:

processing the reference image by means of graphic processing means so as to obtain the graphic decoration to be applied on the surface of the compacted powder layer.

3. A method according to claim 1 , prior to the step of processing in order to identify the trajectories of the most significant surface chromatic effects, the method further comprising the step of:

filtering the surface image of the compacted powder layer so as to remove the possibly present background noise.

4. A method according to claim 3 , prior to the filtering step, the method further comprising the step of:

processing the surface image so as to increase the contrast between the surface chromatic effects and a background of the compacted powder layer.

5. A method according to claim 1 , further comprising the step of:

applying a covering primer enamel on the surface of the compacted powder layer before printing the graphic decoration on said surface.

6. A method according to claim 1 , further comprising a separation step of:

separating the compacted powder layer into single slabs, each provided with respective surface chromatic effects and with respective chromatic effects in the thickness.

7. A method according to claim 6 , wherein the separation step is prior to the printing step.

8. A system for manufacturing ceramic products comprising:

a feeding assembly to feed a mixture containing at least two ceramic powders having different features and/or colours from one another so as to obtain a powder material strip (CP);

a pressing unit to press the powder material strip, which is arranged downstream of the feeding assembly so as to obtain a compacted powder layer provided with respective surface chromatic effects and with respective chromatic effects in the thickness; and

a printing device, which is designed to create a graphic decoration on the surface of the compacted powder layer to thereby make the compacted powder layer more similar to a natural product;

wherein the system comprises an optical detection device, which is arranged upstream of the printing device and is designed to acquire a surface image of the compacted powder layer, which reproduces the respective surface chromatic effects; and

a processing unit, which receives the surface images of the compacted powder layer from the optical detection device and processes them so as to obtain the graphic decoration to be transmitted to the printing device, the processing unit further:

identifying a reference image of the surface image of the compacted powder layer within an archive, where a plurality of reference images are stored, each of the reference images reproducing given surface chromatic effects; and

processing the reference image so as to obtain the graphic decoration to be applied on the surface of the compacted powder layer,

wherein the step of identifying a reference image of the surface image of the compacted powder layer comprises the further steps of:

processing the surface image of the compacted powder layer so as to identify the trajectories of the most significant surface chromatic effects to be compared with the reference images contained in said archive; and

identifying, among the reference images contained in said archive, the one that is the most similar to the surface image of the compacted powder layer,

wherein the graphic decoration is coordinated with the respective chromatic effects in the thickness of the compacted powder layer.

9. The system according to claim 8 , wherein the optical detection device comprises a digital camera with a grayscale scan line.

10. The system according to claim 8 , further comprising:

a cutting device, wherein:

the cutting device is designed to separate the compacted powder layer into single slabs; and

each slab is provided with respective surface chromatic effects and with respective chromatic effects in the thickness.

11. The system according to claim 10 , wherein the optical detection device is interposed between the cutting device and the printing device.