Manufacturing system and method for manufacturing ceramic articles

Abstract

A method and system (1) for manufacturing a ceramic article (T). A manufacturing system (1) comprises: a feeding assembly (2) for feeding a powdered ceramic material (CP); a compaction device (4); a conveyor assembly (6) for transporting the powder ceramic material (CP) along a given path (P) in a direction of movement (A); a degassing assembly (8) arranged upstream of the compacting device (4) along the given path (P) for transmitting vibrations having at least a vertical vibration component, i.e. In the vertical direction, to the powder ceramic material (CP) arranged in use at a section (PA) of the given path (P) in order to densify the powder ceramic material (CP) and obtain a densified powder layer, the densified powder layer is then compacted by a compacting device (4). The length of the section (PA) is between 0.5 m and 2 m.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the priority of Italian Patent Application No. 102022000007550 filed on April 14, 2022, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to a manufacturing system and method for manufacturing ceramic articles, particularly ceramic panels and tiles. Background Art

[0004] In the field of ceramic product production, known methods and systems for manufacturing ceramic products, in particular ceramic slabs and tiles, provide for feeding a semi-dry powder, in particular with a moisture content of about 5%-7%, followed by pressing the ceramic powder to obtain a compacted ceramic powder layer.

[0005] The compaction step (whether performed with a continuous or discontinuous system) is particularly delicate, since an incorrect performance of this step may lead to the appearance of cracks and other defects, at least in part due to a failure to degas the ceramic powder during the compaction step. In fact, the percentage of air in powder materials with a particle size ranging from 200 to 600 μm, which is commonly used in the ceramic field, constitutes more than 50% of the total volume of the powder material. Therefore, the processing of powdered ceramic materials, and in particular their compaction during the so-called degassing step, first requires the removal of a large amount of intergranular air from the spaces between the ceramic powder particles or granules, and then the application of the compaction pressure. Therefore, in other words, in order to perform proper compaction, it is necessary to first remove at least a part of the large amount of air from the intergranular spaces before the actual compaction is carried out.

[0006] This degassing step is usually carried out with a very gentle increase in the compaction pressure in order to give time for the air to escape through the intergranular spaces. In detail, in conventional hydraulically controlled discontinuous presses, this degassing step is carried out by appropriately controlling the hydraulic circuit so as to correctly calibrate the piston displacement in terms of speed and applied force. In a continuous compaction system, on the contrary, this degassing step is carried out by placing the upper compacting belt inclined relative to the conveying plane of the ceramic powder so as to form a gradual reduction of the pores present between the upper (inclined) belt and the lower belt on which the ceramic powder is conveyed, thereby gradually increasing the compaction force so that the intergranular air has time to be expelled.

[0007] As is clear from the foregoing, this degassing step slows down the manufacturing cycle of the ceramic article because it requires slow pressing, which must be done slowly to ensure proper degassing of the ceramic powder.

[0008] It is also clear that the greater the thickness of the ceramic powder to be compacted, the longer this evacuation step will be overall.

[0009] This results in a limitation in the maximum processable thickness (and therefore in the thickness of the ceramic article) at the same production speed and / or a limitation in the production speed at the same thickness and compaction quality.

[0010] The following documents related to a system for manufacturing known types of ceramic products using a conventional press are reported: document CN201244859Y, which relates to a feeding device for manufacturing ceramic coatings; document JPH10264134A, which relates to a method and apparatus for feeding powder material to a conventional discontinuous press; document CN205685520U, which focuses on a grid for loading a conventional discontinuous press; and document JP2008194987A, which relates to a method for forming large-sized ceramic products using a conventional press.

[0011] Also noteworthy are WO2021048797A1 relating to an apparatus for manufacturing ceramic plates and / or stone slabs, and document KR20160149306A describing a method and system for manufacturing ceramic products by means of a continuous compaction system. Summary of the invention

[0012] The object of the present invention is to provide a system and a method for manufacturing ceramic articles which are able to at least partially overcome the limitations of the prior art while increasing the production speed and thickness of ceramic powder layers that can be processed with the same compaction quality.

[0013] According to the present invention, there is provided a method and a system for manufacturing a ceramic article as set out in the accompanying independent claim and preferably in any claim directly or indirectly dependent on the independent claim.

[0014] The claims describe preferred embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The invention will now be described with reference to the accompanying drawings, which illustrate some non-limiting embodiments, in which:

[0016] - Figure 1 shows a schematic side view of a portion of a system for manufacturing a ceramic article according to an embodiment of the present invention;

[0017] - Figure 2 shows a schematic side view of a portion of a system for manufacturing a ceramic article according to another embodiment of the present invention;

[0018] - Figure 3 A schematic side view showing a portion of a system for manufacturing a ceramic article according to yet another embodiment of the present invention; and

[0019] - Figure 4 A graph showing the particle size distribution of ceramic powders used to make ceramic articles is shown. DETAILED DESCRIPTION

[0020] In the attached drawings, numeral 1 denotes as a whole a system for manufacturing a ceramic product T. In particular, the ceramic product T is essentially (but not necessarily) a flat product, in particular a ceramic plate; more precisely, tiles of different sizes, for example, such as large sizes with a cross section of 1200 / 1800×2400 / 3600 mm, or smaller sizes with a cross section of 900 / 1200×1800 / 2000 mm, up to 400×400 mm), etc., and a thickness ranging from about 3 to about 50 mm, preferably from about 6 mm to about 30 mm.

[0021] The manufacturing system 1 of the ceramic product T includes: a feeding assembly 2, which is configured to feed a powdered ceramic material CP to an input station 3; a compacting device 4, which is arranged at a compacting station 5 and is configured to compact the powdered ceramic material CP (in particular, as will be explained below, a dense powder layer S including the powdered ceramic material CP—formed by the powdered ceramic material CP—) to obtain (i.e., form) a compacted powder layer KP; and a conveyor assembly 6, which is configured to transport the powdered ceramic material CP along a given path P extending in a moving direction A at least from the input station 3 to the compacting station 5, and to transport the compacted powder layer KP along the same given path P at least out of the compacting station 5 (see Figure 1 , Figure 2 and Figure 3 ).

[0022] Advantageously, but not limitingly, the feeding assembly 2 comprises at least one feeding device 7 , such as a hopper, of known type and not further described herein, for feeding a (metered) amount of powdered ceramic material CP at the input station 3 .

[0023] Advantageously, but not limitingly, the ceramic article T comprises (in particular is formed of) a powdered ceramic material CP including clay, sand, feldspar and other minerals, which are ground together and atomized to obtain a homogeneous composition.

[0024] Furthermore, advantageously but not necessarily, the powdered ceramic material CP comprises (particularly, is formed of) a semi-dried ceramic powder. Figure 4 As can be seen from the particle size curve shown, the semi-dried ceramic powder has a moisture content in the range of from about 5% to about 10% and a measured particle size in the range of from about 200 μm to about 600 μm. Figure 4The size of the particles forming the powder ceramic material CP, in particular the equivalent diameter, is shown in the abscissa, and the % of the material having such size characteristics included in the above-mentioned powder ceramic material CP is shown in the ordinate.

[0025] In an advantageous but non-limiting detail, the particle size profile is constructed by a sieving device comprising a sieve having pores of decreasing size in the range from about 600 μm to about 63 μm.

[0026] Advantageously, but not restrictively, the manufacturing system 1 for the ceramic product T also includes at least one ceramic product firing kiln (known and not further described or shown herein), which is configured to fire basic ceramic products CB comprising a compacted ceramic powder layer KP (in particular, they are formed by at least a portion of the compacted ceramic powder layer KP) to obtain finished ceramic products T, i.e. ceramic panels or tiles.

[0027] Furthermore, advantageously, the manufacturing system 1 of the ceramic product T comprises a degassing unit 8 (i.e., a densification unit 8) which is arranged upstream (in particular, immediately adjacent) of the compacting device 4 along the given path P and is configured to transfer the vibration action (in Figures 1 to 3 ) is transmitted to the powder ceramic material CP located at (i.e., passing / going through) a section PA of a given path P during use, so as to densify the powder ceramic material CP and obtain a densified powder layer S, as described above, and then the densified powder layer S is compacted by the compacting device 4. In detail, advantageously, the compacting device 4 is configured to transmit the compaction pressure to the densified powder layer S to obtain the above-mentioned compacted powder layer KP.

[0028] Advantageously, but not restrictively, said section PA of a given path P associated with the above-mentioned vibrating action (i.e., at which the vibrating action is transmitted) extends (immediately) upstream of the compacting station 5 and has an extension in the range of from at least about 0.5 m to about 2 m, in particular from about 1 m to about 1.5 m. Even more advantageously, but not restrictively, such section PA of a given path P extends between the input station 3 and the compacting station 5, and even more advantageously, such section PA comprises a portion of the given path P which starts (i.e., begins) immediately after the input station 3 and which extends in the direction of movement A over a length in the range of from about 0.5 m to about 2 m.

[0029] According to other advantageous but non-limiting embodiments, not shown, the conveyor assembly 6 comprises: an upper conveyor device, for example a conveyor belt extending along a first branch of a path P determined from the input station 3 to the discharge station; a lower conveyor device, arranged at a lower height than the upper conveyor device and extending along a second branch of the path P determined downstream of the first branch; and a so-called fence device, arranged at the discharge station, immediately downstream of the upper conveyor device and immediately upstream of the lower conveyor device along the determined path P, and configured to receive the encrypted powder layer S from the upper conveyor device and to guide it onto the lower conveyor device. In this case, advantageously but not limitatively, the section PA of the given path P associated with the above-mentioned vibration action (i.e., at which the above-mentioned vibration action is transmitted) extends along the first branch of the given path P, in particular between the input station 3 and the discharge station, and has an extension in the range from at least about 0.5 m to about 2 m, in particular, from 1 m to about 1.5 m.

[0030] Advantageously, the section PA is dimensioned so as to ensure densification of the powder material CP placed and moved along the section PA in use, due to the vibration effect transmitted by the above-mentioned degassing (ie densification) unit 8.

[0031] According to some advantageous but non-limiting embodiments, the conveyor assembly 6 is configured to move the powdered ceramic material CP at least along the section PA at a moving speed in the range of about 1 meter per minute (particularly about 5 meters per minute) to about 100 meters per minute (particularly about 12 meters per minute). This ensures that the powdered ceramic material CP is subjected to the vibration action for a period of time sufficient to ensure proper densification of the powdered ceramic material CP itself, i.e., to remove at least part of the intergranular air contained between the granules of the powdered ceramic material CP.

[0032] In detail, in the present disclosure, the expression "degassing (ie, densification) of the powder ceramic material CP" refers to the evacuation of at least a part (advantageously, a majority) of air present between the pellets of the powder ceramic material CP.

[0033] Advantageously, but not limitingly, the above-mentioned vibration action for achieving such degassing / densification has a vibration frequency in the range from about 1 Hz (in particular, from about 10 Hz) to about 1000 Hz (in particular, to about 200 Hz).

[0034] In addition, advantageously but not limitingly, the above-mentioned vibration effect has at least one (especially, it is essentially) up and down vibration component (sussultatory component). In other words, advantageously but not limitingly, the vibration effect includes at least one movement component along the vertical direction (especially, the vertical direction is essentially perpendicular to the movement direction A; even more particularly, the vertical direction is essentially perpendicular to the movement plane defined by the conveyor assembly 6 along the aforementioned given path P); more particularly, the vibration effect includes (especially, is) an essentially vertical effect.

[0035] According to some advantageous but non-limiting embodiments (for example, those shown), the conveyor assembly 6 includes at least one conveyor 9, which extends from the input station 3 to at least one compacting station 5 through at least a section PA of a given path P, and the degassing / densification unit 8 includes at least one vibration generator 10 for generating the above-mentioned vibration effect, and at least one transmission element 11, which is connected to the conveyor 9 (advantageously, but not restrictively, mechanically) to transfer the vibration effect from the vibration generator 10 to the conveyor 9 (for example, a conveyor belt or trolley to be further explained below), to (at least) a section PA of the given path P, so as to transfer the vibration effect to the powdered ceramic material CP located on the section PA (i.e., passing / transported along the section PA) and densify it.

[0036] Advantageously but not limitingly, the vibration generator 10 comprises (particularly consists of) an eccentric motor of a known type suitable for generating the above-mentioned vibration effect and not further described herein. In particular, according to certain advantageous but non-limiting embodiments, the vibration generator 10 comprises (particularly consists of) a mechanical system suitable for vibrating a mass of at least about 0.1 kg and less than about 10 kg at a vibration frequency of at least about 1 Hz, in particular in the range from at least about 1 Hz to about 1000 Hz (in particular, from at least about 10 Hz to about 200 Hz).

[0037] It will be understood that, according to other advantageous but non-limiting embodiments, the vibration generator 10 may be of electromagnetic, pneumatic or piezoelectric type, conveniently in communication (advantageously mechanically) with the conveyor 9 at least in the section PA of the given path P.

[0038] In particular, advantageously but not limitingly, the transmission element 11 comprises (in particular, is formed by) a plate arranged (advantageously but not limitingly) below the conveyor 9 and in contact with the conveyor 9. Advantageously but not limitingly, such a plate has a length (i.e. an extension along said movement direction A) in the range from at least about 0.5 m to about 2 m, so as to affect the powdered ceramic material CP along the entire section PA and transmit the vibration action to the powdered ceramic material CP.

[0039] In detail, in the embodiment shown in the figures, the vibration generator 10 is arranged below the transmission element 11 and in contact with the transmission element 11 , in particular with a plate which in turn is in contact with the conveyor 9 .

[0040] According to an alternative embodiment not shown, the vibration generator 10 is arranged spaced apart (in other words, not in contact) relative to the transmission element 11, and the manufacturing system 1 (in particular, the degassing / encryption unit 8) includes a mechanical transmission system, which is configured to transmit the vibrations to the transmission element 11; for example, the vibration generator 10 can be arranged above the conveyor assembly 6 to facilitate access to it, for example in the case of adjustments, maintenance operations, etc.

[0041] According to another non-limiting embodiment not shown, the vibration generator 10 comprises (in particular, consists of) a sound wave generator, such as a speaker suitable for generating sound waves of a suitable frequency, which is arranged to transmit the vibration and generate the above-mentioned vibration effect. Alternatively or additionally, according to certain non-limiting and not shown embodiments, the vibration generator 10 can be arranged to transmit the vibration effect to the powder ceramic material CP immediately downstream of the feeding station 2, in particular immediately downstream of the feeding device 7, so as to encrypt the powder ceramic material CP once the powder ceramic material CP is fed to the conveying assembly 6 (even before it reaches the conveying assembly 6).

[0042] According to some advantageous but non-limiting embodiments (such as Figure 2), the conveyor assembly 6 is configured to transport the powder ceramic material CP, the densified powder layer S and the compacted powder layer KP along a given path P in a substantially continuous manner. Advantageously but not restrictively, in this case (i.e., when the conveyor assembly 6 is of the substantially continuous type), the conveyor assembly 6 is configured to move the densified powder layer S and the compacted powder layer KP along the given path P at a speed ranging from about 1 meter per minute to about 10 meters per minute. Moreover, advantageously but not restrictively, in this case, the compacting device 4 (which is known per se) comprises: an upper compacting belt 13, which is arranged above the conveyor 9 at the compacting station 5 and cooperates with the conveyor 9 to compact the densified powder layer S in a substantially continuous manner, thereby obtaining the compacted powder layer KP. In this case, advantageously but not restrictively, the conveyor assembly also includes an additional conveyor 9' arranged downstream of the conveyor 9 along the given path P to receive the compacted powder layer KP and guide it to the cutting station 14, which will be further explained below. Even more advantageously, but not limitingly, there is an intermediate conveyor (see also 9 ) advantageously with rollers between the conveyor 9 and the subsequent conveyor 9 ′. Figure 2 ).

[0043] According to an alternative, advantageous but non-limiting embodiment, for example Figure 1 In the embodiment shown, the compacting device 4 (known per se) comprises: a lower compacting belt 12 in contact with the conveyor 9, and an upper compacting belt 13, which is arranged above the conveyor 9 at the compacting station 5 and cooperates with the lower compacting belt 12 to compact the dense powder layer S in a substantially continuous manner, thereby obtaining the compacted powder layer KP.

[0044] In this case, advantageously, the conveyor 9 comprises (in particular is formed by) a conveyor belt which advantageously but not restrictively encloses this lower compacting belt 12 therein and which extends from the input station 3 to the outlet of the compacting station 5 via a section PA of a given path P. In this case, advantageously but not restrictively, this section PA extends upstream (immediately) of the compacting belts 12 and 13 along the given path P, so that the powdered ceramic material in use is first densified by the vibration action transmitted at this section PA and then, once densified, is compacted by the compacting device 4 (as described above).

[0045] Furthermore, according to other non-limiting embodiments that are particularly advantageous when processing a high thickness of the powdered ceramic material CP without compromising the production speed (more specifically the speed of movement of the conveyor 9), the manufacturing system 1 of the ceramic article T provides for feeding the powdered ceramic material CP via two different feeding devices 7 arranged in sequence along a given path P and densifying the powdered ceramic material CP at two separate times. In this case, advantageously but not limitingly, the section PA of the given path P comprises (in particular, is subdivided into) two portions T1 and T2 that are advantageously arranged one behind the other without interruption along the movement direction A (see Figure 2 ), and the feeding assembly 2 comprises a first feeding device 7 and a second feeding device 7, the first feeding device 7 being configured to feed a first amount of powdered ceramic material CP in the region of a first portion T1 of the section PA, the second feeding device 7 being arranged downstream of the first feeding device 7 along a given path P and being configured to feed a second amount of powdered ceramic material CP in the region of a second portion T2 of the section PA along a given path P (on the first amount of powdered ceramic material CP to be fed in use) (see Figure 2 ), the second portion T2 being located downstream of the first portion T1. In this case, advantageously but not restrictively, the degassing / cooling unit 8 comprises at least one further transport element 11 ', which is arranged downstream of the transport element 11 along the given path P and is (advantageously mechanically) connected to the conveyor 6 to transmit the vibration action from the vibration generator 10 or 10' to the conveyor 6. In detail (advantageously but not necessarily), the transport element 11 ' is arranged to transmit the vibration action to the conveyor 9 arriving at the first portion T1 of the section PA, so as to densify the first quantity of powdered ceramic material CP in use; and the further transport element 11 ' is arranged to transmit the vibration action to the conveyor 9 arriving at the second portion T2 of the section PA, so as to densify the second quantity of powdered ceramic material CP fed onto the first quantity in use.

[0046] According to alternative advantageous but non-limiting variants (such as Figure 2 In the variant shown), the degassing / encryption unit 8 includes a vibration generator 10 connected to the transmission element 11 (for example, arranged directly below the transmission element 11 as shown in the figure) and a further vibration generator 10', which is similar to the previous vibration generator and is arranged downstream along the given path P and directly below the further transmission element 11'.

[0047] According to some advantageous but non-limiting embodiments, such as those described herein (see e.g. Figure 1 and Figure 2), the manufacturing system 1 for ceramic products T comprises at least one cutting station 14 arranged downstream of the compacting station 5 along a given path P, wherein a cutting device 15 (known per se and not further described herein) cuts the compacted ceramic powder layer KP to obtain a plurality of basic ceramic products BC, which are then fired in a firing kiln (not shown) as described above to obtain the final ceramic product T.

[0048] According to other advantageous but non-limiting embodiments (such as Figure 3 ), the manufacturing system 1 of the ceramic product T is of discontinuous type. In this case, advantageously but not limitingly, the compacting device 4 is a discontinuous type press and comprises a mold 16, a drive unit (not shown) to operate the mold 16 and to impart a defined compaction pressure to the densified powder layer S in use. In detail, advantageously but not limitingly, the mold 16 comprises a lower half mold 17 and an upper half mold (in Figure 3 The lower mold half 17 and the upper mold half are arranged to face each other and can be moved towards and away from each other, in particular in the vertical direction, to define a compacting chamber 18 between them, which is intended to receive the encrypted powder layer S to be compacted.

[0049] According to some advantageous but non-limiting embodiments (such as Figure 3 ), the conveyor 9 is a movable distribution grid between a loading position C and a release position R, at which the conveyor 9 receives a given amount of powdered ceramic material CP, and at which the conveyor 9 releases a given amount of powdered ceramic material CP into the compacting chamber 18. In detail, advantageously but not restrictively, the conveyor 9 also includes a carriage (in particular, is formed by the carriage), which can be operated by the aforementioned drive unit to move the distribution grid between the loading position C and the release position R (see Figure 3, wherein the distribution grid in the release position R is shown in dotted lines), and the feeding device 7 comprises a hopper (in particular, is formed by the hopper) having an adjustable discharge opening to adjust the amount of powdered ceramic material CP to be fed onto the conveyor 9, in particular into the distribution grid. Advantageously, but not restrictively, in this case, the conveyor 9 (in particular, the above-mentioned carriage) is configured to move the distribution grid between the loading position C and the release position R at a speed in the range from about 5 meters per minute to about 150 meters per minute (in particular, to about 120 meters per minute). Advantageously, but not restrictively, the section PA of the given path P extends at said loading position C. Even more particularly, in this case, the transport element 11 of the degassing / densification unit 8 comprises a sliding plate arranged below the conveyor 9 at said loading position C to transmit the above-mentioned vibration action to the given amount of powdered ceramic material CP loaded into the distribution grid to densify it and obtain a densified powder layer S.

[0050] In detail, in this case, advantageously but not limitingly, the compacted powder layer KP coincides with the basic ceramic product CB, since the distribution grid is loaded by the feeding device 7 with metered quantities of powdered ceramic material CP which, once densified and compacted, forms the basic ceramic product CB.

[0051] Furthermore, advantageously but not restrictively, in this case, the compacting device 4 also includes a discharge device (known in itself and not shown or further described herein) which can be operated by a drive unit to discharge the compacted powder layer KP (in particular, the base ceramic product CB) from the compacting station 5 to an outlet along a given path P.

[0052] According to another aspect of the present invention, a manufacturing process for a ceramic product T is proposed, which provides a feeding step, during which a feeding component 2 (advantageously but not limited to the type described above with respect to the manufacturing system 1 for the ceramic product T) feeds powdered ceramic material CP to an input station 3; a compacting step, during which a compacting device 4 (advantageously but not limited to the type described above with respect to the manufacturing system 1 for the ceramic product T) is operated to obtain a compacted powder layer KP, and the compaction will encrypt the powder layer S as explained below; and a conveying step, during which a conveying unit 6 (advantageously but not limited to the type described above with respect to the manufacturing system 1 for the ceramic product T) transports the powdered ceramic material CP from the input station 3 to the compacting station 5 in the aforementioned moving direction A along the aforementioned given path P, and transports the compacted powder layer KP along the given path P to at least the outlet of the compacting station.

[0053] Advantageously, the manufacturing process of the ceramic product T also includes a degassing step (i.e., a densification step) (at least partially) before the compaction step and (at least partially) after the feeding step, during which degassing step, a degassing / densification unit 8 arranged upstream of the compaction device (4) along the given path (P) transmits a vibration action to the powdered ceramic material CP to obtain a densified powder layer S, which is compacted during the compaction step when the compaction device 4 compacts the densified powder layer S to obtain the compacted powder layer KP.

[0054] Advantageously, but not restrictively, during this degassing / encryption step, the degassing / encryption unit 8 transmits the above-mentioned vibration action for a duration ranging from at least about 3 seconds to about 20 seconds (in particular, for a duration ranging from about 5 seconds to about 15 seconds; even more in particular, for a duration of about 12 seconds).

[0055] Advantageously, but not restrictively, during the conveying step, the conveyor 9 (advantageously of the type described above) moves the powdered ceramic material CP through a section PA of said given path P; as already mentioned above with respect to the manufacturing system 1 for ceramic products T, this section PA extends upstream of (immediately adjacent to) the compacting station 5 and has an extension in the range of from at least about 0.5 m to at least about 2 m, in particular from about 1 m to about 1.5 m.

[0056] According to certain advantageous but non-limiting embodiments, the degassing (i.e., densification) step includes a vibration generating sub-step and a transmission sub-step, during which the above-mentioned vibration effect is generated (advantageously but not limitatively, with the aid of a vibration generator 10 manufactured according to one of the above-mentioned embodiments), and during the transmission sub-step, a transmission element 11 (advantageously but not limitatively of the above-mentioned type) connected to the conveyor component 6, in particular to the conveyor 9 (advantageously but not limitatively mechanically) transmits the vibration effect to the conveyor component 6 (in particular the conveyor 9), to the section PA, so that the powdered ceramic material CP positioned and moved to the section PA during use is densified.

[0057] Regarding the vibration action, the considerations set out above regarding the system 1 for manufacturing a ceramic article T remain valid. In detail, advantageously but not limitingly, the vibration action has a vibration frequency ranging from about 1 Hz to about 1000 Hz, in particular from about 10 Hz to about 200 Hz.

[0058] According to some embodiments, such as Figure 1 and Figure 2In the embodiments schematically shown in the figure, during the transport step, the conveyor assembly 6 transports the powder ceramic material CP, the densified powder layer S and the compacted powder layer KP along a given path P in a substantially continuous manner; in this case, the compaction step and the degassing / densification step are (at least partially) carried out simultaneously with the transport step. Moreover, advantageously but not restrictively, during the compaction step (at least partially) after the densification step, the densified powder layer S is compacted by a continuous compacting device 4, which is advantageously but not restrictively implemented as described above with respect to the manufacturing system 1 for ceramic products T. In particular, advantageously but not restrictively, with particular reference to Figure 2 The continuous compacting device 4 comprises at least one upper compacting belt 13 arranged above the conveyor 9, and during the compacting step, the conveyor 9 and the upper compacting belt 13 cooperate to compact the dense powder layer S in a substantially continuous manner to obtain a compacted powder layer KP.

[0059] Alternatively, advantageously but not restrictively, with particular reference to Figure 1 The continuous compacting device 4 includes at least a lower compacting belt 12 arranged below and in contact with the conveyor 9 and an upper compacting belt 13 arranged above the conveyor 9, and during the compaction step, the lower compacting belt 12 and the upper compacting belt 13 cooperate to compact the dense powder layer S in a substantially continuous manner to obtain a compacted powder layer KP.

[0060] Furthermore, as already mentioned with respect to system 1, according to some advantageous but non-exclusive variants, the feeding step provides a first feeding sub-step and a second feeding sub-step (at least partially) following the first feeding step, during which the first feeding sub-step the first feeding device 7 feeds a first amount of powdered ceramic material CP to the area of ​​the first part T1 of the segment PA, and during which the second feeding sub-step the second feeding device 7 arranged downstream of the first feeding device 7 along a given path P (on the first amount of already encrypted powdered ceramic material CP) feeds a second amount of powdered ceramic material CP to the area of ​​the second part T2 of the segment PA downstream of the first part T1. In this case, in practice, the degassing / encryption step includes a first degassing (i.e., encryption) sub-step (at least partially) after the first feeding step and (at least partially) before the second feeding step, and a second degassing (i.e., encryption) sub-step (at least partially) after the first degassing (i.e., encryption) sub-step and the second feeding step, during which the first amount of powder material CP is encrypted, and during which the second degassing (i.e., encryption) sub-step is encrypted.

[0061] According to other advantageous but non-limiting embodiments (e.g. Figure 3), the conveying step comprises a first transport sub-step, during which the conveyor 9 (in this case comprising (particularly formed by) a movable distribution grid) receives a given amount of powdered ceramic material CP at a loading position C and transports it, advantageously but not restrictively, along the above-mentioned section PA to a release position R. Advantageously but not restrictively, the degassing (i.e., densification) step is carried out (at least partially) simultaneously with the first transport sub-step; more particularly (advantageously but not restrictively), the degassing (i.e., densification) step occurs when the conveyor 9 is in the loading position C.

[0062] Advantageously but not restrictively, during the compaction step, the dense powder layer S is compacted in a discontinuous mold 16 (advantageously but not restrictively, of the type described above, i.e., having at least one lower half mold 17 and a second upper half mold not shown, said lower half mold 17 and the second upper half mold being arranged facing each other and being movable towards and away from each other) to compact the dense powder layer S and obtain a compacted powder layer KP, in particular the basic ceramic product CB as explained above with respect to the manufacturing system 1 for the ceramic product T.

[0063] The method and system 1 for manufacturing a ceramic article T of the present invention has several advantages, including the following.

[0064] Due to the degassing / densification unit, at least a portion (particularly a large portion) of the air present between the granules of the ceramic powder material CP is evacuated before the powder material CP is subjected to the pressure required for compaction. This makes it possible to settle the particles (i.e., granules) of the powder ceramic material CP, promote and accelerate the subsequent compaction action, resulting in a favorable increase in the compaction efficiency, which is considered to be the maximum compaction ratio that can be achieved according to the final density of the ceramic product T.

[0065] In fact, after the degassing (i.e., densification) step, and therefore after the degassing / densification action performed by means of the degassing (i.e., densification) unit 8, it is surprisingly observed that the thickness of the powder ceramic material CP fed by the feeding assembly 2 is reduced by at least about 8% (in particular, from 8% to about 20%), which promotes compaction.

[0066] The result is that for the same thickness of the powdered ceramic material CP to be compacted, the production speed increases, or for the same production speed, the thickness of the powdered ceramic material CP to be compacted increases.

Claims

1. A manufacturing system (1) for a ceramic product (T), wherein the ceramic product (T) is in particular a ceramic plate or a tile; the manufacturing system (1) comprises: at least one feeding assembly (2) for feeding powdered ceramic material (CP) to an input station (3); a compacting device (4) arranged at the compacting station (5) to obtain a compacted powder layer (KP); a conveyor assembly (6) configured to transport the powdered ceramic material (CP) in a moving direction (A) along a given path (P) from the input station (3) to the compacting station (5), and to transport the compacted powder layer (KP) at least out of the compacting station (5) along the given path (P); The manufacturing system (1) of the ceramic product (T) is characterized in that it comprises a degassing unit (8) which is arranged upstream of the compacting device (4) along the given path (P) and is configured to transmit a vibration action having at least an up and down vibration component to the powdered ceramic material (CP) arranged at a section (PA) of the given path (P) in use, so as to densify the powdered ceramic material (CP) and obtain a densified powder layer (S); The section (PA) extends upstream of the compacting station (5) and has a length ranging from at least about 0.5 m to at least about 2 m; and The compacting device (4) is configured to transmit compaction pressure to the densified powder layer (S) to obtain the compacted powder layer (KP).

2. The manufacturing system (1) of a ceramic product (T) according to claim 1, wherein the vibration frequency of the vibration action is in the range from about 1 Hz (especially from about 10 Hz) to about 1000 Hz (especially to about 200 Hz).

3. A system (1) for manufacturing a ceramic product (T) according to any one of the preceding claims, wherein the conveyor assembly (6) is configured to move the powdered ceramic material (CP) at a moving speed in the range of from about 1 meter per minute (particularly, about 5 meters per minute) to about 150 meters per minute (particularly, about 120 meters per minute) at least in the area of ​​the section (PA) of the given path (P).

4. A system (1) for manufacturing a ceramic product (T) according to any one of the preceding claims, wherein: The conveyor assembly (6) comprises at least one conveyor (9) extending from the input station (3) through the section (PA) of the given path (P) to at least the compacting station (5); and The degassing unit (8) comprises at least one vibration generator (10) for generating the vibration effect and at least one transmission element (11) connected to the conveyor (9) to transmit the vibration effect from the vibration generator (10) to the conveyor (9) at the section (PA) of the given path (P).

5. A manufacturing system (1) for ceramic products (T) according to claim 4, wherein the transmission element (11) includes (in particular, is) a plate arranged under the conveyor (9) and in contact with the conveyor (9), and the length of the plate is in the range from at least about 0.5m to at least about 2m.

6. The manufacturing system (1) of a ceramic product (T) according to claim 4 or 5, wherein: The conveyor assembly (6) is configured to transport the powdered ceramic material (CP), the densified powder layer (S) and the compacted powder layer (KP) along the given path (P) in a substantially continuous manner; The compacting device (4) comprises a compacting belt (13) arranged above the conveyor (9) at the compacting station (5) and cooperating with at least the first conveyor (9) in order to compact the densified powder layer (S) in a substantially continuous manner, thereby obtaining the compacted powder layer (KP); The conveyor (9) comprises a conveyor belt (particularly, consists of a conveyor belt); In particular, said section (PA) of said given path (P) extends along said given path (P) upstream of said compacting belt (13).

7. The manufacturing system (1) of a ceramic product (T) according to claim 6, wherein: The feeding assembly (2) comprises at least a first feeding device (7) and a second feeding device (7), the first feeding device (7) being configured to feed a first amount of powdered ceramic material (CP) at a first portion (T1) of the section (PA), the second feeding device (7) being arranged downstream of the first feeding device (7) along the given path (P), and being configured to feed a second amount of powdered ceramic material (CP) at a second portion (T2) of the section (PA), the second portion (T2) being downstream of the first portion (T1) along the given path (P); the degassing unit (8) comprising at least one further transport element, which is arranged downstream of the at least one transport element (11) along the given path (P) and is connected to the conveyor (9) to transmit the vibration action from the vibration generator (10) to the first conveyor (9); The at least one transmission element (11) is arranged to transmit the vibration action to the conveyor (9) at the first part (T1) of the section (PA) so as to densify the first amount of powdered ceramic material (CP) during use; and the further transmission element (11) is arranged to transmit the vibration action to the conveyor (9) at the second part (T2) of the section (PA) so as to densify the defined second amount of powdered ceramic material (CP) during use.

8. The system (1) for manufacturing a ceramic product (T) according to any one of claims 1 to 5, wherein: The compacting device (4) comprises a mould (16) which in turn comprises a compacting chamber (18) and is configured to apply a defined compacting pressure to the densified ceramic powder layer (S) in order to obtain a compacted powder layer (KP) (in particular, a basic ceramic product (CB)); The conveyor (9) is a distribution grid movable between a loading position (C) and a release position (R), wherein the distribution grid receives a given amount of powdered ceramic material (CP) and releases the given amount of powdered ceramic material (CP) into the compacting chamber (18); and the section (PA) of the given path (P) extends in the region of the loading position (C); In particular, the transport element (11) of the degassing unit (8) comprises a sliding plate which is arranged below the conveyor (9) in the area of ​​the loading position (C) so as to transmit the vibration action to the given amount of powdered ceramic material (CP) loaded on the distribution grid (9) during use so as to densify it.

9. A method for producing a ceramic product (T), in particular a ceramic plate or a tile, comprising: a feeding step during which the feeding assembly (2) feeds the powdered ceramic material (CP) to the input station (3); a compacting step, during which a compacting device (4) arranged at a compacting station (5) is operated to obtain a compacted powder layer (KP); as well as a conveying step, during which a conveyor assembly (6) transports the powdered ceramic material (CP) in a moving direction (A) along a given path (P) from the input station (3) to the compacting station (5), and transports the compacted powder layer (KP) at least out of the compacting station (5) along the given path (P); The method for manufacturing a ceramic product (T) is characterized in that it comprises a degassing step at least partially before the compacting step and at least partially after the feeding step, during which a degassing unit (8) arranged upstream of the compacting device (4) along the given path (P) transmits a vibration action having at least an upper and lower vibration component to the powdered ceramic material (CP) to obtain a dense powder layer (S); and during the compacting step, the compacting device (4) compacts the dense powder layer (S) to obtain the compacted powder layer (KP).

10. The method for manufacturing a ceramic product (T) according to claim 9, wherein: During the degassing step, the degassing unit (8) transmits the vibration action to the powdered ceramic material (CP) for an amount of time ranging from at least about 3 seconds to about 20 seconds (particularly, for an amount of time ranging from about 5 seconds to about 15 seconds; more particularly, for an amount of time of about 12 seconds).

11. The method for manufacturing a ceramic product (T) according to claim 9 or 10, wherein: During the conveying step, a conveyor (9) moves the powdered ceramic material (CP) through a section (PA) of the given path (P); and The degassing step comprises a vibration generation sub-step, during which the vibration action is generated, and a transmission sub-step, during which a transmission element (11) connected to the conveyor assembly transmits the vibration action to the conveyor assembly (6) in the area of ​​the section (PA) of the given path (P) in order to densify the powdered ceramic material (CP) arranged in the area of ​​the section (PA) in use; In particular, the vibration frequency of the vibration action is in the range from about 1 Hz (in particular, from about 10 Hz) to about 1000 Hz (in particular, to about 200 Hz).

12. The method for manufacturing a ceramic product (T) according to claim 9, 10 or 11, wherein: During the conveying step, the conveyor assembly (6) transports the powdered ceramic material (CP), the densified powder layer (S) and the compacted powder layer (KP) along the given path (P) in a substantially continuous manner; The compacting step and the degassing step are at least partially performed simultaneously with the transporting step; The compacting step at least partially follows the degassing step, and during the compacting step, the conveyor (9) and at least one compacting belt (13) arranged above the conveyor (9) cooperate to compact the encrypted powder layer (S) in a substantially continuous manner, thereby obtaining the compacted powder layer (KP).

13. The method for manufacturing a ceramic product (T) according to claim 12, wherein: The feeding step comprises a first feeding sub-step and a second feeding sub-step at least partially following the first feeding sub-step, during which a first feeding device (7) feeds a first amount of powdered ceramic material (CP) at a first portion (T1) of the section (PA), and during which a second feeding device (7) arranged downstream of the first feeding device (7) along the given path (P) feeds a second amount of powdered ceramic material (CP) at a second portion (T2) of the section (PA), the second portion (T2) being downstream of the first portion (T1) along the given path (P); The degassing step comprises a first degassing sub-step and a second degassing sub-step at least partially following the first degassing sub-step, during which the first amount of powder material (CP) is densified, and during which the second amount of powder material (CP) is densified.

14. The method for manufacturing a ceramic product (T) according to claim 11, wherein: The conveying step comprises a first transport sub-step, during which the conveyor (9) comprising (in particular consisting of) a movable distribution grid receives a given amount of powdered ceramic material (CP) at a loading position and transports it along the section (PA) to a release position; The degassing step is performed at least partially simultaneously with the first transporting substep; and During the compacting step, at least partially subsequent to the degassing step, a mould (16) applies a defined compacting pressure to the densified powder layer (S) to obtain a compacted powder layer (KP).

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