Patent Application
20250026038
This patent application claims priority from Italian Patent Application No. 102021000030488 filed on Dec. 1, 2021 the entire disclosure of which is incorporated herein by reference.
The present invention relates to a cutting method of a layer of ceramic powder material, and to a manufacturing process and manufacturing plant of ceramic articles.
In particular, the present invention finds advantageous application in the field of production of ceramic articles, such as ceramic tiles and slabs of various formats, to which the following description will make explicit reference without losing generality.
In the field of the production of ceramic articles (in particular, slabs; more in particular, tiles) there are known manufacturing plants that provide for the feeding (typically in a substantially continuous manner) of semi-dry ceramic powder (i.e. with a moisture content that is lower than 12%, in particular ranging from 5% to 7%) along a given path through a continuous compaction assembly, which subjects the ceramic powder to a compaction pressure, so as to obtain a band of compacted ceramic powder, which is subsequently cut to obtain a plurality of articles of compacted ceramic powder, having different dimensions according to the type of ceramic article to be obtained, which will then be dried, possibly decorated, and fired in order to obtain the final ceramic products.
The known cutting methods and systems generally provide for a cutting station in which abrasive tools, typically grinding wheels or rotating blades or cylindrical cutters, intercept and cut the band of compacted ceramic powder, generating articles of compacted ceramic powder of various dimensions that are then subjected to subsequent drying, decoration and firing operations.
However, the known methods and systems have drawbacks, including the following.
The cutting systems and methods of the known type envisage using abrasive tools which, besides being very expensive in themselves, are subject to wear and require frequent maintenance and/or replacement operations that can only be performed by stopping the manufacturing cycle with further obvious disadvantages in terms of costs, times and production efficiency.
In addition, the cutting systems and methods of known type present numerous issues related to the large amount of waste powder produced by the abrasive tools during cutting, which, if not recovered by appropriate expensive suction systems, risks dirtying the plant compromising the operation of the components of the plant and/or the aesthetic appearance of the final ceramic articles.
In addition, in the cutting systems and methods of known type, the cutting tools are not able to completely pass through the layer of powder, leaving in the lower end area of the section a small burr that must be removed with other work stations before the firing step. This deburring represents a plant complication and an increase in the cost of the plant.
Aim of the present invention is to provide a cutting method, a manufacturing process and manufacturing plant of ceramic articles, which make it possible to overcome, at least partially, the drawbacks of the known art and are, at the same time, easy and economical to manufacture.
In accordance with the present invention, there are provided a cutting method and a manufacturing process and manufacturing plant of ceramic articles as claimed in the independent claims below and, preferably, in any of the claims dependent directly or indirectly on the independent claims.
The claims describe preferred embodiments of the present invention.
The present invention will now be described with reference to the enclosed drawings, showing some non-limiting embodiments thereof, wherein:
In accordance with a first aspect of the present invention, in
With particular reference to
Advantageously but not in a limiting manner, the ceramic powder CP (i.e. a semi-dry mixture, in particular having a moisture content ranging from 5% to 7%) is mainly silicate-based, i.e. it comprises at least about 35% (in particular, at least about 40%) by weight relative to the total weight of the silica ceramic powder CP (SiO2) and less than about 50% (in particular, less than about 30%) by weight, relative to the total weight of the ceramic powder CP, of alumina (Al2O3).
According to some non-limiting embodiments (such as those schematically shown in
Advantageously, the manufacturing plant 1 to manufacture ceramic articles T also comprises a cutting system 12 arranged at a cutting station 13 and configured to cut a layer S of ceramic powder material, having a breaking load, measured in accordance with EN ISO 10545 Part 4, which is smaller than about 10 N/mm2, in particular smaller than about 8 N/mm2, to obtain articles of ceramic powder material MCP; and a firing kiln 14 (in itself known and not further described herein) which is arranged downstream of the cutting system 12 along the moving direction A to fire the articles of ceramic powder material MCP, advantageously imposing a firing temperature of about 1000-1300° C., so as to obtain ceramic articles T, in particular ceramic slabs, even more in particular ceramic tiles.
The conveyor assembly 7 is, therefore, also configured to convey the layer S of ceramic powder material at least through the cutting station 13 and the articles of ceramic powder material MCP from the cutting station 13 to the firing kiln 14 (possibly passing through a drier 15 and/or a decoration unit 16—as shown for example in
In detail, advantageously but not in a limiting manner, the conveyor assembly 7 also comprises at least a further conveyor device 17, for example a roller conveyor (like in the embodiments of
According to some advantageous but not limiting embodiments (such as those schematically shown in
Furthermore, according to yet some advantageous but not limiting embodiments, the manufacturing plant 1 to manufacture ceramic articles T, also comprises a decoration unit 16 (in itself known and not further described herein) which is configured to apply at least some enamel on the layer S of ceramic powder material (in particular, on the dried band of ceramic powder KP′ so as to obtain an enamelled band of ceramic powder KP″, or on the band of compacted ceramic powder KP so as to obtain an enamelled band of ceramic powder KP′″ or on the already cut and dried articles of ceramic powder material MCP, as will be explained later in this discussion).
In particular, in the present discussion, the term “layer S of ceramic powder material” refers to a layer comprising (in particular, consisting of) ceramic powder CP which is compacted by means of the compaction device 5 but not yet fired. In particular (as will be clearer from the following description of some embodiments of the invention), in some non-limiting cases (such as the one shown in
Advantageously but not in a limiting manner, the aforementioned layer S of ceramic powder material exhibits a loss on ignition (which is a measure of the weight variation of a dried sample measured at about 100° C. after it has been heated at a high temperature above 1000° C. causing combustion and volatilization of part of its content) that is ranging from about 1% to about 80% of the initial weight.
Advantageously, the cutting system 12 comprises at least one water-jet cutting device 21, which is advantageously arranged at a transverse cutting site 22, and is configured to cut the layer S of ceramic powder material along a direction D1 that is orthogonal (in particular, transverse) to the moving direction A. Even more advantageously but not in a limiting manner, the cutting system 12 also comprises at least a further water-jet cutting device 19, which is advantageously arranged at a longitudinal cutting site 20, and is configured to cut the layer S of ceramic powder material along a direction D2 which is parallel to the moving direction A so as to obtain articles of ceramic powder material MCP.
In detail, advantageously, each water-jet cutting device 19, 21 comprises a respective nozzle (not visible in the attached Figures) which is arranged and configured to dispense a jet G of water under pressure (schematically shown in
It is understood that according to further non-limiting and not shown embodiment, the water-jet cutting devices 19, 21 could be arranged below the conveying assembly 7, in particular below the conveyor device 17, so as to dispense the jet on a lower surface of the layer S of ceramic powder material or a portion P1 thereof.
Advantageously but not in a limiting manner, the conveyor device 17 comprises (in particular, is made up of) a roller conveyor or a belt or a net having, at the cutting station 13, openings 29 (at least in a number equal to the number of water-jet cutting devices 19, 19′, 21, 21′) to allow the passage of the jet G of water under pressure during cutting (see the schematic representation of
According to some advantageous but not limiting embodiments such as the one schematically shown in
Alternatively or in addition, advantageously but not in a limiting manner, the cutting station 13 could be protected by a protection system (not shown and in itself known) and/or provided with suction devices to avoid the risk of (excessive) dispersion of water in the plant 1.
Advantageously but not necessarily, the nozzle of each cutting device 19, 21 comprises an outlet hole having a diameter of about 0.10-1.00 mm (in particular, 0.20-0.70 mm) and is configured to dispense the jet G of water under pressure so that it intercepts this layer S of ceramic powder material (in particular the upper surface thereof) with a pressure that is greater than about 1500 bar; in particular, greater than about 3000 bar; even more in particular, greater than about 3600 bar; and advantageously but not in a limiting manner smaller than about 6000 bar.
Advantageously but not in a limiting manner, the water under pressure of the jet G of water under pressure comprises (in particular, is made up of) pure water and at most about 10 g/l (in particular, at most about 5 g/l; even more in particular, at most about 2 g/l) of solid particles. Even more advantageously but not in a limiting manner, the jet G of water under pressure comprises (in particular, is made up of) pure water and from about 0 (excluded) g/l (in particular, from about 0.3 g/l) to about 10 g/l (in particular, to about 5 g/l; even more in particular, to about 2 g/l) of solid particles (in other words, the jet G of water under pressure comprises pure water and an amount of solid particles varying from about 0 (excluded) g/l—in particular, from about 0.3 g/l-to about 10 g/l—in particular, to about 5 g/l-even more in particular, to about 2 g/l). The aforementioned solid particles, advantageously but not in a limiting manner, have an equivalent diameter which is smaller than about 10 μm (in particular, smaller than about 1 μm). Surprisingly, the present invention allows an optimal cutting of the layer S of ceramic powder material even using substantially pure water.
Even in more detail, according to some advantageous but not limiting embodiments (such as the one schematically shown in
According to advantageous but not limiting alternative embodiments (such as the one schematically shown in
According to yet other embodiments (such as the one schematically shown in
Advantageously but not in a limiting manner, according to some embodiments schematically shown in
Even more advantageously, according to some non-limiting embodiments (which are particularly advantageous when the layer S of ceramic powder material coincides with the band of compacted ceramic powder KP or with the enamelled band of ceramic powder KP′″ and the cutting system 12 is arranged upstream of the drier 15), the two water-jet cutting devices 19 and 19′ are side by side transversely to the moving direction A spaced apart from each other, dispensing the jet G of water under pressure so as to remove two opposite side end portions of the layer S of ceramic powder material while this moves along the moving direction A by performing the so-called trimming operation and obtaining a portion (i.e. strip) P1 of said layer S of ceramic powder material. Alternatively, according to other embodiments not shown (and which are particularly advantageous when the layer S of ceramic powder material is made up of the dried band of ceramic powder KP′ or of the enamelled band of ceramic powder KP″ and the cutting system 12 is arranged downstream of the drier 15 or of the decoration station 16) the two (or more) water-jet cutting devices 19 and 19′ are side by side transversely to the moving direction A spaced apart from each other so as to cut the layer S of ceramic powder material into three (or more) portions (i.e. strips).
With particular reference to
In particular (advantageously but not necessarily), in use, the control unit CU operates the support structure 24 and the water-jet cutting device 21 so that it is operated to dispense the respective jet G of water under pressure while translating along the direction D3. Advantageously but not in a limiting manner, the control unit CU is configured to operate the support structure 24 so as to allow the water-jet cutting device 21 to translate along said direction D3 at a translation speed VT which is a function of the inclination of said direction D3 relative to the moving direction A. In other words, the control unit CU is configured to ensure a synchronization between the translation speed VT of the water-jet cutting device 21 and the speed at which the layer S of ceramic powder material or the portion P1 thereof moves along the moving direction A so that said layer S of ceramic powder material or the portion P1 is cut along the transverse direction D1. Even in more detail, according to some advantageous but not limiting embodiments, the cutting speed VT is proportional to the speed at which the layer S of ceramic powder material or the portion P1 is moved along the moving direction A and the proportionality constant is a function of the inclination of said direction D3 relative to said moving direction A, advantageously it is equal to about the reciprocal of the cosine of the angle α of inclination that the direction D3 forms relative to the moving direction A.
Even more advantageously but not in a limiting manner, this direction D3 is inclined relative to the moving direction A by an angle α ranging from about 45° to about 80°.
According to some advantageous but not limiting variants, the support structure 24 comprises a guide 25 which extends above the conveyor assembly 7, in particular the conveyor device 17, along said direction D3, a sliding support body (not visible in the attached Figures) which supports the cutting device 21 and a drive (not shown in the attached Figures, for example a linear motor) which can be operated by the control unit CU to induce the translation of the sliding support body along the guide 25 while the layer S of compacted ceramic powder or a portion thereof P1 moves on the conveyor assembly 7, in particular on the conveyor device 17, advantageously at the translation speed VT.
With particular reference to
In particular, in this case, the control unit CU is configured to control the conveyor assembly 7, in particular the conveyor device 17, so as to stop the layer S of ceramic powder material at the transverse cutting site 22, and subsequently activate the support structure 24 so as to induce the translation of the water-jet cutting device 21 so that the respective jet G of water under pressure intercepts and cuts the surface of the layer S of ceramic powder or a portion thereof along the transverse direction D1 so as to obtain the articles in ceramic powder material MCP.
In detail, advantageously but not in a limiting manner, also in this case, the support structure 24 comprises a guide 25 that extends above the conveyor assembly 7, in particular the conveyor device 17, along the transverse direction D1, a sliding support body (not visible in the attached Figures) that supports the cutting device 21 and a drive (not shown in the attached Figures, in itself known, for example a linear motor) that can be operated by the control unit CU to induce the translation of the sliding support body along said guide 25 while the layer S of ceramic powder material lies or the portion P1 (i.e. is stationary) at the transverse cutting site 22.
According to some advantageous but not limiting variants of such embodiments (such as the one shown in
Advantageously, but not in a limiting manner, in this case, the water-jet cutting devices 19, 19′, 21 and 21′ are carried, respectively, by the support 23 and by the support structure 24 so that the hole of the respective nozzle (of each water-jet cutting device 19, 19′, 21 and 21′ is located above the conveying plane at a distance (i.e. at an elevation) relative to the layer S of ceramic powder material or to the portion P1 (in particular, relative to the upper surface of the layer S of ceramic powder material or of said portion P1) that is smaller than about 15 mm, in particular smaller than about 10 mm. This position ensures an optimal cutting action by the jet G of water under pressure.
With particular reference to
Advantageously but not in a limiting manner, the cutting system 12 comprises two water-jet cutting devices 21, 21′, which are arranged in the transverse cutting site 22 substantially side by side with each other transversely to the moving direction A so that once they have been operated they dispense the respective jet G of water at two fixed points of the transverse cutting site 22 while the portion P1 is located (in particular, goes through) along the segment T2 of the given path P. Even more advantageously, the cutting devices 21, 21′ are carried by such further support 26 and placed side by side with each other, as mentioned above for the transverse cutting devices 19, 19′.
In detail, according to some non-limiting variants of such embodiments (such as the one shown in
In detail, advantageously but not in a limiting manner, the deflection assembly 27 comprises (in particular, is made up of) at least two guide bars which are arranged on the conveyor assembly 7, in particular on the conveyor device 17, and which can be operated, by the control unit CU, to intercept two orthogonal sides of the portion P1 of the layer S of ceramic powder material and induce the aforementioned rotation thereof by about 90°. Alternatively, the deflection assembly 27 could comprise a gripping system that grips and moves the (i.e., each) portion P1 of the layer S of ceramic powder material.
According to another variant schematically shown in
Also in this case, advantageously but not in a limiting manner, the cutting devices 19, 19′, 22 and 21′ are carried, respectively, by the support 23 and by the support 26 so that the hole of the respective nozzle of each water-jet cutting device 19, 19′, 22 and 21′ is located above the conveying plane at a distance (i.e. at an elevation) relative to the layer S of ceramic powder material or to the portion P1 (in particular, relative to the upper surface of the layer S of ceramic powder material or to the portion P1) that is smaller than about 15 mm, in particular smaller than about 10 mm. This position ensures an optimal cutting action by the jet of water under pressure.
It is understood that according to other non-limiting embodiments not shown, each cutting device 19, 19′, 21 and 21′ could be carried by the respective support 23, 26 or by the support structure 24 so as to be able to adjust, manually or through the control unit CU, the distance of the hole of the respective nozzle relative to the layer S of ceramic powder material or of the portion P1 (in particular, relative to the upper surface of the layer S of ceramic powder material or of the portion P1).
It goes without saying that according to other non-limiting embodiments not shown, each cutting device 19, 19′, 21 and 21′ could be connected to one end of a respective anthropomorphic robot operated by the control unit CU to move along given trajectories during the cutting operations described above. In particular, the use of anthropomorphic robots makes it possible to create non-rectilinear cutting profiles (for example, wavy or jagged lines to imitate natural materials, etc.). Furthermore, this case, advantageously but not necessarily, the anthropomorphic robot could be configured to also carry the aforementioned collection device 30 (comprising—in particular made up of—a collection cup) arranged below the aforementioned openings 29 provided on the conveyor device 29 so as to collect the water of the jet G of water under pressure.
According to some advantageous but not limiting embodiments not shown, the manufacturing plant 1 to manufacture ceramic articles T, in particular the cutting system 12 comprises a recovery assembly 31 (schematically shown in
According to some advantageous but not limiting embodiments such as the one schematically shown in
In particular, according to some advantageous but not limiting embodiments, the system of ducts 32 is configured to convey the water of the jet G of water under pressure from the collection container 30 to a ceramic mixture preparation station, where such water is used as normal process water within the grinding mill 33, possibly after having passed into a stirring or storage tank 34 (see
It is further understood that the cutting system 12 could have its own control unit, different from the control unit CU, and be configured to control the cutting system 12, in particular each component of the cutting system, for example the cutting devices 19, 19′, 21, 21′, (when present) the support structure 24, (when present) the deflector assembly 27, etc.
According to a further aspect of the present invention there is proposed a cutting method of a layer S of ceramic powder material having a modulus of rupture that is smaller than about 10 N/mm2, in particular smaller than about 8 N/mm2, measured in accordance with UNI EN ISO 10545-4:2019 Ceramic tiles—Part 4:Determination of the modulus of rupture and the breaking strength and advantageously but not in limiting manner a loss on ignition (which is a measure of the weight variation of a dried sample measured at about 100° C. after it has been heated to a high temperature above 1000° C. causing combustion and volatilization of part of its content) that is ranging from about 1% to about 80% of the initial weight.
As mentioned above with reference to the plant 1, the term “layer S of ceramic powder material” means a layer comprising (in particular, consisting of) ceramic powder CP which has been compacted by means of the compaction device 5 but not yet fired. In detail, the “layer S of ceramic powder material”, in some cases, comprises (in particular, coincides with) the band of compacted ceramic powder KP or its part, in other cases, it comprises (in particular, coincides with) the dried band of ceramic powder KP′ or with the enamelled band of ceramic powder KP″ or their part and in other cases it comprises (in particular, coincides with) the enamelled band of ceramic powder KP″′ or its part.
The cutting method comprises: a moving step, during which the layer S of ceramic powder material is moved by a conveyor assembly 7 along a given path P in a moving direction A through a cutting station 13; and a cutting step, during which at least one water-jet cutting device 21 cuts the layer S of ceramic powder material along a direction D1, which is orthogonal in particular transverse to the moving direction A so as to obtain at least a portion P1 of said layer S. Advantageously but not in a limiting manner, during this cutting step at least a second water-jet cutting device 19 cuts the layer S of ceramic powder material or its portion P1 along a direction D2, which is parallel to the moving direction A, so as to cut the layer S of ceramic powder material or its portion P1 and obtain a plurality of articles of ceramic powder material MCP.
As mentioned above in relation to the plant 1, advantageously, the water-jet cutting devices 19, 21 each comprise a respective nozzle configured to dispense a jet G of water under pressure (in particular, having a pressure that is greater than about 1500 bar; in particular, than about 3000 bar; even more in particular than about 3600 bar) which, during the cutting step the layer S intercepts and cuts the layer S of ceramic powder material (in particular a surface, advantageously an upper surface, of the layer S of ceramic powder material).
Advantageously but not in a limiting manner, during the cutting step each cutting device 19, 21 dispenses a jet G of water under pressure comprising (in particular, made up of) pure water and at most about 10 g/l (in particular, at most about 5 g/l; even more in particular, at most about 2 g/l) of solid particles. Even more advantageously but not in a limiting manner, during this cutting step, each cutting device 19, 21 dispenses a jet G of water under pressure comprising (in particular, made up of) pure water and from about 0 (excluded) g/l (in particular, from about 0.3 g/l) to about 10 g/l (in particular, to about 5 g/l; even more in particular, to about 2 g/l) of solid particles. Such solid particles advantageously have an equivalent diameter which is smaller than about 10 μm (in particular, smaller than about 1 μm.
The fact that the water jet G is substantially made up of pure water with a minimum percentage of particulate matter allows, unlike some well-known water-jet cutting systems (for example for cutting fired ceramic articles) that envisage using water having a high amount of abrasives in its inside, to recover the water of the jet G of water under pressure after carrying out the cut, and to reuse it possibly by re-introducing it in the manufacturing cycle of the ceramic articles T (as explained above), for example inside the mill or to wash other parts of the plant 1, since this waste water is substantially clean water that contains, at most, dissolved or suspended ceramic powder material in its inside.
Advantageously, but not in a limiting manner, the method comprises a recovery step, which is (at least partially) subsequent to the cutting step, during which the water of the jet G of water under pressure dispensed during the cutting step is recovered to be reused, for example by re-introducing it in the manufacturing cycle of the ceramic articles T or to wash the manufacturing plant 1 to manufacture the ceramic articles T or its part.
Advantageously but not in a limiting manner, the cutting step comprises a longitudinal cutting sub-step and a transverse cutting sub-step, which is (at least partially) subsequent to the longitudinal cutting step. In particular (as already explained in relation to the plant 1), advantageously, during the cutting sub-step, the aforementioned at least one water-jet cutting device 19 arranged at a longitudinal cutting site 20 cuts the layer S of ceramic powder material along the longitudinal direction D2, while this layer S of ceramic powder material is moved along the given path P through the longitudinal cutting site 20; while during the transverse cutting sub-step, the aforementioned at least one water-jet cutting device 21 cuts the layer S of ceramic powder material along the transverse direction D1.
Even more advantageously but not in a limiting manner, during the longitudinal cutting sub-step, two water-jet cutting devices 19 and 19′ (advantageously of the type described above in relation to the plant 1) are arranged in the longitudinal cutting site 20 substantially side by side with each other transversely to the moving direction A (in particular, in a fixed position) so as to dispense the respective jet G of water at two fixed points of this longitudinal cutting site 20, so as to intercept the layer S of ceramic powder material that moves along the moving direction A along two substantially linear and parallel cutting paths. In detail, as already said for the plant 1, the two cutting devices 19, 19′ are preferably but not necessarily spaced apart from each other so as to perform the so-called trimming operation obtaining the aforementioned portion P1 or so as to obtain three (or more) portions, in particular in three strips.
According to some advantageous but not limiting embodiments of the method (such as the one schematically shown in
Advantageously, but not in a limiting manner, according to some variants (such as the one shown in
Alternatively, according to other advantageous but not limiting variants (such as those shown in
Even in more detail, as already mentioned in relation to the plant 1, advantageously but not in a limiting manner, according to some non-limiting embodiments (such as the one shown in
According to yet a further aspect of the present invention there is proposed a manufacturing process to manufacture ceramic articles T (such as those described above).
Said manufacturing process to manufacture ceramic articles T comprises a feeding step, during which the ceramic powder CP is fed to an input station 4; a compaction step, during which said ceramic powder CP is compacted by a compaction device 5 which is arranged at a compaction station 6, said compaction device 5 (advantageously but not in a limiting manner of the type described above) applies a compaction pressure on the ceramic powder so as to obtain a band of compacted ceramic powder KP; a cutting step, implemented in accordance with the cutting method above, during which the aforementioned layer S of ceramic powder material (for which the above considerations apply) is cut in order to obtain a plurality of articles of ceramic powder material CP; a firing step, during which the articles of ceramic powder material CP are fired in a firing kiln 14, heating them up to a temperature of about 1000-1300° C., so as to obtain ceramic articles T; and a conveying step, during which a conveyor assembly 7 (advantageously but not in a limiting manner of the type described above) which extends along a given path P in a moving direction A conveys the ceramic powder CP from an input station 4 to the compaction station 6, the band of compacted ceramic powder KP out of the compaction station 6, and the layer S of ceramic powder material at least through the cutting station 13.
In detail, advantageously but not necessarily, the cutting step performed according to one of the embodiments described above is (at least partially) simultaneous with the conveying step, (at least partially) subsequent to the compaction step and (at least partially) prior to the firing step.
According to some advantageous but not limiting embodiments, the manufacturing process further comprises a drying step, during which a drier imposes a temperature of about 120-300° C. on the band of compacted ceramic powder KP (or on the already formed article of ceramic powder material MCP) so as to obtain a dried band of ceramic powder KP′ (or to dry the article of ceramic powder material MCP). In addition, according to some non-limiting embodiments, the manufacturing process to manufacture ceramic articles T also comprises an enamelling step that is at least partially subsequent to the drying step and at least partially prior to the cutting step, during which the enamel is applied on the dried band of ceramic powder KP′ (or on the already dried article of ceramic powder material MCP) so as to obtain an enamelled band of ceramic powder KP″ (or an enamelled article of ceramic powder material MCP).
According to other embodiments of the present invention (like for example those shown in
According to yet other advantageous but not limiting embodiments such as the one shown in
In particular, as already mentioned above in relation to the plant 1 and to the cutting method, when the layer S of ceramic powder material coincides with the dried band of compacted ceramic powder KP′, the cutting step (which advantageously but not in a limiting manner—as better explained above-provides for a longitudinal cutting sub-step in which the layer S of ceramic powder material is cut to obtain the portion P1 and a transverse cutting sub-step which may envisage that the portion P1 is stopped at the cutting site 22 and that the—each—cutting device 21 and 21′—cuts said portion P1 while moving along the cutting path PT in the transverse direction D1, or that the portion P1 is cut, by fixed cutting devices 21, 1′ while moving along the segment T2 of the given path P) is (at least partially) subsequent to the drying step and when provided for to the enamelling step.
Alternatively, according to other non-limiting embodiments (such as the one schematically shown in
The cutting method and the plant 1 and the manufacturing process to manufacture ceramic articles T of the present invention have numerous advantages, including the following.
The present invention makes it possible to cut a layer S of ceramic powder material having a thickness varying from about 3 mm, to about 50 mm, in particular to about 30 mm, making the cut with high precision, without inducing the occurrence of surpluses, irregularities or burrs along the cut edge. In addition, the present invention ensures high efficiency by allowing the cutting to be carried out at a speed ranging from about 1 metre per minute to about 30 metres per minute as the characteristics vary, in terms of composition of the ceramic powder material, physical state—before or after drying—and/or molecular structure—e.g., crystalline, glassy, dissolved, etc.—, of the thickness of the layer S of ceramic powder material.
Furthermore, the use of water-jet cutting devices 19, 19′, 21, 21′ for cutting such as those described above, which do not produce waste powder, means that the present invention can also be used (as explained above) to cut ceramic powder material already dried and/or already enamelled without risking compromising its quality. It follows that the present invention, by envisaging the possibility of cutting a dried band of ceramic powder KP′ or an enamelled band of ceramic powder KP″, allows a unique processing for the entire layer/band of ceramic powder material regardless of the type (in particular the format) of ceramic article T to be obtained.
In addition, relative to some known cutting systems and methods that provide for cutting the already fired ceramic articles, the present invention allows cutting ceramic powder material which is less resistant than the already fired material whose cutting can be done much faster and without the use of abrasive material, with all the consequent advantages in terms of environment and recovery of the waters used by the cutting devices 19, 19′, 21, 21′. In addition, cutting before firing allows a faster firing, having to fire articles of ceramic material MCP having smaller dimensions.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102021000030488 | Dec 2021 | IT | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2022/061595 | 11/30/2022 | WO |
