System for the manufacturing of ceramic items and related method

Abstract

A system (1) for the manufacturing of ceramic items, in particular ceramic slabs or tiles, comprising: - a conveyor assembly (4) comprising an upper (5) and a lower (6) conveyor device; - a feeding assembly (2) with feeding devices for feeding powder material (CP) to the upper conveyor device (5); - an unloading assembly (3) comprising an unloading device (8) with an unloading channel (9) for receiving the powder material (CP) from the upper conveyor device (5) and feeding it to the lower conveyor device (6). The unloading device (8) comprises a front wall (11) and a rear wall (12), opposite and spaced apart from one another, defining between them the unloading channel (9). In the area of a proximal end (EP) of the unloading channel (9), the front wall (11) has a flat first panel (11A), inclined so that the first panel (11A) and the rear wall (12) converge to one another. The upper conveyor device (5) is configured to feed the powder material (CP) at least partially tangentially to the first panel (11A).

Description

[0001] SYSTEM FOR THE MANUFACTURING OF CERAMIC ITEMS AND RELATED METHOD

[0002] Cross-Reference to Related Applications

[0003] This Patent Appl ication claims priority from Italian Patent Application No . 102024000021122 filed on September 23 , 2024 , the entire disclosure of which is incorporated herein by reference .

[0004] Technical Field

[0005] The invention relates to a system for the manufacturing of ceramic items and to a relative method; in particular ceramic slabs and tiles , even more in particular ceramic slabs and tiles having inner streaks or veins .

[0006] In particular, the invention advantageously (but not exclusively) applies to a system that manufactures ceramic items through compaction of granular material or powders ( in particular spray-dried, ground or regranulated semi-dry powders mixed together in a predetermined or random manner ) .

[0007] Background of the Invention

[0008] In the field of the ceramic item manufacturing industry, there is an increasing need to manufacture ceramic items , such as ceramic s labs and tiles , whose aesthetic appearance reproduces as closely as possible the appearance of natural stones , such as marble , granite , etc . , or wood .

[0009] In particular, the aim is to reproduce the pattern that characterises natural stones or wood and that typically features a main background colour and a series of streaks / veins of di f ferent colours and shapes that develop randomly throughout the thickness of the background colour so as to be visible both on the outer surface of the final ceramic items and on the edges ; in such cases , these are referred to as "through veins .

[0010] In some known systems for the manufacturing of ceramic items , the layer of ceramic powder material that reproduces the desired pattern is created on a first conveyor and compacted on a second conveyor, which is arranged at a lower height than the first conveyor and to which the layer of ceramic powder material is fed by means of an unloading device ( such as for example a hopper arranged substantially vertically) configured to level out the layer of ceramic powder material , so that said layer reaches the compaction station ( in which a continuous or discontinuous pressing takes place ) with an even thickness . In detail , the unloading device generally comprises a wall and a conveyor belt arranged parallel to and at a defined distance from one another, which de fines the even thickness that the layer of ceramic powder material will assume once unloaded from said unloading device .

[0011] However, this solution is af fected by several drawbacks , among which the following ones are worth being mentioned .

[0012] First of all , the unloading channel shaped as mentioned above has the disadvantage that the shape of the decoration in full thickness , which is recreated on the lower conveyor, exclusively depends on parameters intrinsic to the powder material ( such as for example friction) . As a consequence , operators have no parameter to change the shape of the pattern at the exit of the unloading device .

[0013] As a consequence , the pattern created on the layer of ceramic powder material in the area of the first upper conveyor, while maintaining a simi lar overall layout , tends to deform when it goes through the unloading device ( this ef fect is more pronounced the less even the thickness of the layer of ceramic powder material is before reaching the unloading device , that is , the more the level of the layer of ceramic powder material deviates from the hori zontal at the entry of the unloading device ) . In order to address the problem, manufacturers generally use viewing systems designed to detect the deformation of the pattern of the layer of ceramic powder material , once unloaded from the unloading device , and graphic correction systems to be arranged on the second lower conveyor to try and correct such deformations , and / or digital printing devices to make surface decorations on the layer of compacted ceramic powder material to try and reproduce the desired aesthetic appearance .

[0014] In addition, in known solutions , in which the relative position between the digital feeding assembly ( or conveyor belt ) and the unloading device is usually established by means of mechanical adj ustments defined during the machine testing phase , a limitation has also been observed regarding the variation of the level of ceramic material present inside the unloading device . In other words , the free surface of the ceramic material in the unloading device is irregular, for it has areas where there is an excess of material and areas where there is a shortage of material with respect to the theoretical level (namely, a hori zontal level along the entire width ( dimension measured transversely, in particular orthogonally, to a conveying direction in which the ceramic material is conveyed to the unloading device ) . In particular, the level of the ceramic material inside the unloading device can vary due to local variations in the ceramic material in terms of grain si ze and humidity . As a consequence , the theoretical flow rate of the ceramic material fed to the unloading device can vary from point to point along the width of the unloading device .

[0015] Due to the aforementioned deviation (variation) from the optimal (namely, constant and minimum) distance between the unloading device and the first conveyor, a di f ficulty was observed in the control in terms of positioning ( deposition) of the ceramic material that moves relative to and / or separates itsel f from and / or gets mixed with the ceramic material adj acent to it inside the unloading device , thus contaminating (mixing) the colours .

[0016] In other words , the variation in the level of powder material in the unloading device turns into a variation in the distance between the aforesaid free surface and the first conveyor, which causes a variability in the sharpness of the pattern, that is to say in the precision and def inition of the layer of material in the area of the second lower conveyor . However, since the sharpness of the pattern is one of the fundamental requirements for the evaluation of the quality of the finished product (namely, of the ceramic item) obtained using the system, it is important to increase it as much as possible , so as not to compromise the aesthetic appearance of the final ceramic item, in particular in terms of degree of similarity with natural stones or wood .

[0017] Some examples of known solutions disclosed for example in CN111702939A, CN108943361B and CN115648412A involve the use of funnels designed to convey the material in bulk into the unloading device .

[0018] The obj ect of the invention is to provide a system for the manufacturing of ceramic items , which is designed to at least partly overcome the drawbacks of the prior art . Summary

[0019] According to the invention, there are provided a system and a relative method for the manufacturing of ceramic items according to the independent claims attached hereto and, preferably, according to any one of the dependent claims directly or indirectly depending on the aforesaid independent claims .

[0020] The appended claims describe pre ferred embodiments of the invention and form an integral part of the description .

[0021] Brief Description of the Drawings

[0022] The invention wi ll now be described with reference to the accompanying drawings , which show some non-limiting embodiments thereof , wherein : figure 1 is a schematic perspective view (with some parts removed for greater clarity) of a system for the manufacturing of ceramic items according to a first embodiment of the invention;

[0023] - figure 2 is a schematic perspective view (with some parts removed for greater clarity) of a system for the manufacturing of ceramic items according to a second embodiment of the invention; and

[0024] - figure 3 is a schematic cross section view (with some parts removed for greater clarity) of an unloading assembly of figure 1 or 2 .

[0025] Detailed Description

[0026] In the accompanying figures , number 1 indicates , as a whole , a system 1 for the manufacturing of ceramic items . In particular, the ceramic items are ceramic slabs or tiles . Even more in particular, the invention advantageously but not exclusively applies to the manufacturing of ceramic slabs and tiles having full-thickness inner streaks or veins , to which explicit reference will be made in the description below without thereby lacking generality.

[0027] The pattern, shown in a merely schematic manner and by way of example in figure 2, is defined on the layer of powder material CP with chromatic effects in the (entire) thickness of the ceramic items. In other words, it is possible to obtain a pattern with a so-called "through vein". These chromatic effects are, for example, visible veins or streaks in the edges of the ceramic items.

[0028] The system 1 for the manufacturing ceramic items comprises at least: a feeding assembly 2, an unloading assembly 3 and a conveyor assembly 4.

[0029] The feeding assembly 2 is configured to feed the powder material CP to the unloading assembly 3 (in the area of an input station SI) , which, in turn, is configured to feed the powder material CP to the conveyor assembly 4 (in the area of an unloading station S2; in particular, above the conveyor assembly 4) . The unloading station S2 is arranged downstream of the input station SI.

[0030] In detail, the conveyor assembly 4 is configured to convey (advantageously, though not necessarily, in a substantially continuous or discontinuous manner) a powder material CP along a conveying path P (schematically indicated by a means of a dashed line in figure 1) . In particular, the conveyor assembly 4 is arranged and configured to support, from below, the layer of powder material CP and a layer of compacted powder KP (obtained as described below) along the given conveying path P.

[0031] The conveyor assembly 4 comprises an upper conveyor device 5 (for example, a conveyor belt shown in figures 1 and 2) and a lower conveyor device 6 (for example, a conveyor belt shown in figures 1-3) , which is arranged at a lower height than the upper conveyor device 5, said upper conveyor device 5 and said lower conveyor device 6 defining, between them, a conveying direction A along the predefined conveying path P. The upper conveyor device 5 extends along a segment PA of the given conveying path P; on the other hand, the lower conveyor device 6 extends along a second segment PB of the given conveying path P downstream of the segment PA (see, in particular, figure 1) .

[0032] The upper conveyor device 5 is configured to receive the powder material CP from the feeding assembly 2 and to feed it to the unloading assembly 3, which, in turn, feeds the powder material CP to the lower conveyor device 6.

[0033] Advantageously, but not in a limiting manner, as shown in the accompanying figures, the feeding assembly 2 comprises a plurality of (digital) feeding devices 7, preferably arranged in the area of an input station SI, so as to generate a layer of powder material CP. In particular, in the nonlimiting embodiment shown in figure 2, the feeding assembly 2 comprises six (digital) feeding devices 7 for feeding three different types of powder material CP onto the conveyor assembly 4 so as to form the layer of powder material CP. The different types of powder material CP (schematically shown in figure 2 with different fills) have different colours. Alternatively or in addition, the different types of powder materials have different physical characteristics. According to a possible alternative, at least two of the different types of powder materials can coincide with one another (namely, be substantially the same) , for example in terms of colour or physical characteristics.

[0034] According to some non-limiting embodiments (such as those shown in the accompanying figures ) , the feeding assembly 2 is as disclosed in patent application WO2022195547 ( filed by the Applicant ) .

[0035] The unloading assembly 3 is arranged in the area of the unloading station S2 , immediately downstream of the upper conveyor device 5 and immediately upstream of the lower conveyor device 6 , along the given conveying path P . The unloading assembly 3 is arranged transversely, in particular orthogonally, with respect to the upper conveyor device 5 and the lower conveyor device 6 .

[0036] The unloading assembly 3 comprises an unloading device 8 ( in particular, a hopper arranged substantially vertically) , which is provided with an unloading channel 9 configured to receive the powder material CP from the upper conveyor device 5 and to unload it onto to the lower conveyor device 6 . The unloading device 8 comprises a front wall 11 and a rear wall 12 , which are opposite and spaced apart from one another and define , between them, the unloading channel 9 . In particular, the terms " front" and "rear" are defined with reference to the conveying direction A.

[0037] As shown in the accompanying figures , the unloading channel 9 has a proximal end EP, in the area of which the unloading channel 9 is configured to receive the powder material CP from the upper conveyor device 5 , and a distal end ED, which is opposite the proximal end EP and in the area of which the unloading channel 9 is configured to deliver the powder material CP to the lower conveyor device 6 . The front wal l 11 and the rear wall 12 extend below the upper conveyor device 5 and above the lower conveyor device 6 . In the area of the proximal end EP, at least a portion of the front wall 11 and at least a portion of the rear wall 12 converge towards or diverge from one another .

[0038] According to the embodiment of the invention shown in the accompanying figures , at least a portion of the front wall 11 and at least a portion of the rear wall 12 converge towards one another in the conveying direction A of the material CP (namely, the cross section of the unloading channel 9 decreases in the conveying direction A of the powder material CP ) . In detail , the front wall 11 of the unloading channel 9 comprises at least two flat panels 11A and 11B (which, together, define the front wall 11 ) arranged in succession to one another . The term " flat panel" indicates a panel without curvature , namely having a cross section with a substantially rectangular shape . The panel 11A, which is arranged closer to the proximal end EP than the panel 11B, is inclined at an angle a with respect to the panel 11B, so as to allow the powder material CP to be fed at least partially tangentially to the front wall 11 ( in particular, to the panel 11A) . In particular, to allow the powder material CP to be fed at least partially tangentially in proximity, in terms of relative di stance , of the surface of the panel 11A ( relative distance measured transversely, in particular orthogonally, with respect to the surface ) . Therefore , the upper conveyor device 5 is configured to feed the powder material CP in the area of the panel 11A of the front wall 11 at least partially tangentially to the panel 11A itsel f . Preferably, the feeding of the powder material CP takes place , in particular, mainly (more in particular, substantially exclusively) in the area of the inclined panel 11A. In this way, by having the powder material CP fall at least partially tangentially against the panel 11A and move along the inclined panel 11A before continuing in the unloading channel 9 , there substantially is one single direction of arrangement of the powder material CP inside the unloading channel 9 . The term "tangentially" means that the upper conveyor device 5 is configured to feed the powder material CP as close as possible against the panel 11A, so that the material CP can then continue to move along the inclined panel 11A itsel f .

[0039] Preferably, but not in a limiting manner, the upper conveyor device 5 is also configured to feed the powder material CP as close as possible to the proximal end EP of the unloading channel , so as to take greater advantage of the movement of the powder material CP along the panel 11A. The portion of the rear wall 12 facing the panel s 11A and 11B comprises a single flat panel 12A. The panel 12A is arranged vertical ly or inclined at an angle with respect to a vertical plane . In particular, in figure 3 , this angle between the panel 12A and a possible vertical plane is zero .

[0040] Advantageously, the panels 11B and 12A are parallel to one another or converge towards one another or diverge from one another .

[0041] Preferably, but not in a limiting manner, the panels 11B and 12A preferably diverge from one another in the conveying direction A (namely, the cross section of the unloading channel 9 increases in the conveying direction A of the powder material CP ) . This further leads to an improvement in the flow of the powder material CP in the unloading channel 9 along the conveying direction A, as it prevents the occurrence of the so-called "bridge" ef fect (namely, when the powder material CP, by pushing against the walls 11 and 12 , tends , due to inner friction and other factors , to clump together and get stuck in the unloading channel 9 ) . This "bridge" ef fect occurs more frequently (but not exclusively) in powder materials CP that have a high humidity or that tend to clump together, forming a front of aggregated material that prevents the correct flow of the powder material CP towards the distal end ED of the unloading channel 9 .

[0042] Advantageously, by feeding the powder material CP at least partially tangentially to the front wall 11 ( in particular to the panel 11A) , which is inclined at the angle a, it is possible to have a substantially single direction of arrangement of the powder material CP inside the unloading channel 9 . In other words , by having on one side the panel 11A, which is inclined and therefore acts as a partition, the powder material CP poured into the unloading channel 9 can be arranged mainly ( in particular, exclusively) away from said panel 11A and substantially in one single direction of arrangement that is transverse ( in particular, orthogonal ) to the panel 11A itsel f .

[0043] Advantageously, the panel 11A inclined at the angle a af fects the movement of the powder material CP within the entire extension of the unloading channel 9 , counteracting possible deformations in the thickness during the pressing phase or the pattern creation phase , so as to make the ef fect more natural .

[0044] To this regard, the system 1 for the manufacturing of ceramic item advantageously comprises a compaction device 13 ( schematically shown in figure 1 ) , which is arranged in the area of a compaction station S3 . The compaction station S3 lies along the second segment PB of said given conveying path P . The compaction device 13 is arranged downstream of the unloading device 8 . The compaction device 13 is configured to compact (preferably, in a substantially continuous or discontinuous manner ) the powder material CP .

[0045] Advantageously, but not in a limiting manner ( as shown in figure 1 ) , the compaction device 13 comprises a first compacting belt 13 ' placed under and in contact with the lower conveyor device 6 in the area of a compaction station S3 and a second compacting belt 13 ' ’ , which is arranged above the lower conveying device 6 in the area of the compaction station S3 and cooperates with the first compacting belt 13 ' to compact (preferably, in a substantially continuous or discontinuous manner ) the layer of powder material CP, exerting a transverse ( in particular, normal ) pressure upon the conveyor assembly 4 so as to obtain the layer of compacted powder KP, which is then preferably fed to subsequent processing stations , such as a firing station and / or a cutting station (not shown) . The firing station and / or a cutting station are arranged downstream of the compaction station S3 . According to a possible embodiment , the firing station and / or a cutting station are as disclosed in patent application WO20221115547 ( filed by the Applicant ) .

[0046] Therefore , the shape of the unloading channel 9 , in particular of its front wall 11 (more in particular, of the panel 11A inclined at the angle a ) , improves the graphics of the pattern to be obtained, because it counteracts possible deformations in the thickness during the pressing phase or the pattern creation phase , thus making the ef fect more natural . In other words , it counterbalances the stretching ef fect of the pattern, namely of the streak / vein in the thickness , which would occur in the area of the lower conveyor device 6.

[0047] Advantageously, but not in a limiting manner, the angle a ranges from 3 to 30°, in particular from 5 to 15, more in particular is equal to 10°. The size (surface) of the panel 11A depends on the inclination angle a. Laboratory tests carried out have shown that good results are obtained, in terms of improvement of the conveying dynamics, with an angle a ranging from 3 to 30°. These tests revealed that an angle substantially equal to 10° provides a good compromise (in particular, a substantially optimal condition) between the ease of reading the level of the powder material CP by possible detection devices and the size of the panel 11A (and, therefore, of the unloading device 8 itself) . The laboratory tests also showed that good results are obtained in terms of improvement of the conveying dynamics also with angles a of less than 12° (in particular, greater than 3°) , in this case the panel 11A has a very large surface and, therefore, the unloading device 8 is very high (with a consequent greater sliding and, hence, friction between the powder material CP and the panel 11A itself) , or greater than 12° (in particular, less than 30°) , in this case the panel 11A has a reduced surface and, therefore, the unloading device 8 is very compact (with a consequent reduction in the sliding against the walls and , hence, a smaller slowing down action) .

[0048] Advantageously, but not in a limiting manner, the front wall 11 further comprises, in addition to the panels 11A and 11B, a further panel 11c (which, together with the panels 11A and 11B, constitutes the front wall 11) , which is adjacent to the panel 11B and has a cross section substantially having the shape of an arc of a circle, in particular a quarter of a circle .

[0049] Advantageously, but not in a limiting manner, the rear wall 12 comprises , in the area of the distal end ED, a further panel 12B, which is adj acent to the panel 12A and has an cross section that is initially curved ( in particular, concentric to the panel 11c facing it , i f the latter has a cross section substantially having the shape of an arc of a circle ) and in the end part is substantially straight , so as to accompany the powder material CP towards the lower conveyor device 6 .

[0050] Advantageously, but not in a limiting manner, the system 1 comprises at least one , in particular a plurality of , detection means 14 , each configured to detect the actual level of powder material CP in the unloading channel 9 of the unloading device 8 . In particular, said at least one detection means 14 is configured to detect an actual ( average ) level of the powder material CP . Each detection means 14 comprises ( is ) , in particular, a sensor, preferably analogue (more preferably, of the capacitive or ultrasonic or laser kind) .

[0051] Preferably, but not in a limiting manner, the system 1 comprises at least two detection means 14 , which are arranged, preferably spaced apart from one another, along a direction Y that extends transversely, in particular orthogonally, to the conveying direction A so as to detect the progress of the level of the material along the direction Y and to adj ust , by means of feedback control , the feeding of the powder material CP to the unloading device 8 along the direction Y . By so doing, the accuracy of the level monitoring by the system 1 can be increased .

[0052] Advantageously, but not in a limiting manner, said at least one detection means 14 is arranged in the area of at least one of : a wall 11 or 12 of the unloading device 8 ( in particular, the rear wall 12 of the unloading device 8 ; preferably outside the unloading channel 9 ) ; and the upper conveyor device 5 ( in particular, in the area of the belt of the upper conveyor device 5 ) .

[0053] According to an alternative , non-limiting embodiment , the system 1 is devoid of said at least one detection means 14 and, in this a case , the operator manually controls the level of powder material CP during the start-up phase of the system 1 .

[0054] Advantageously, but not in a limiting manner, in order to further improve the quality of the ceramic item manufactured by means of the system 1 , it comprises an adj ustment device 15 ( schematically shown, but not in a limiting manner, in figure 1 under the upper conveyor device 5 ) configured to manually ( in particular, manually by the operator ) or semi-automatically or ( completely) automatically displace the feeding position of the powder material CP in the unloading channel 9 , as a function of the actual level of powder material CP detected by said at least one detection means 14 .

[0055] Advantageously, but not in a limiting manner, the adj ustment device 15 is configured to automatically displace ( adj ust ) ( in particular, by means of feedback control ) the position of the unloading point of the powder material CP in the unloading channel 9 , varying the distance ( in particular, the vertically measured dimension; namely, the height ) between : the actual level of powder material CP in the unloading channel 9 ; and at least the upper conveyor device 5 or at least one component of the feeding assembly 2 , as a function of the actual level of powder material CP detected by said at least one detection means 14. In this way, the powder material CP can be fed in the unloading channel 9 in a flush manner (in particular, in the area of its free surface) with the powder material CP already present in the unloading channel 9. Therefore, by unloading the powder material CP as much as possible flush with the powder material CP (namely, close to its free surface) , it is possible to obtain a more defined pattern, as the powder material CP fed does not mix with the powder material CP. Therefore, by reducing the distance by means of the adjustment device 15, the sharpness of the pattern is increased .

[0056] Advantageously, but not in a limiting manner, the adjustment device 15 comprises a plurality of actuator devices (such as, for example, hydraulic actuators or electric motors) , which can be operated at least partially independently of one another, so as to perform said variation of the distance. The actuator devices are configured to vary the aforementioned distance even during the operation of the system 1 itself.

[0057] According to a possible, non-limiting embodiment, the actuator devices are configured to (directly) act upon the upper conveyor device 5.

[0058] According to a further different embodiment, which is not limiting, the actuator devices are configured to (directly) act upon the feeding device.

[0059] According to an alternative (non-limiting) embodiment, the actuator devices are arranged, for example, in the area of the supports (such as, for example, the support feet (of the frame) ) of the system 1 so as to lift or lower (vertically, namely orthogonally to the support plane of the system 1 ) not only the upper conveyor device 5 , but also the feeding assembly 2 .

[0060] Advantageously, but not in a limiting manner, the variation of the distance ( in particular, the vertically measured dimension; namely, the height ) between the actual level of powder material CP in the unloading channel 9 and at least the upper conveyor device 5 or at least one component of the feeding assembly 2 is less than 5 cm, in particular 3 cm .

[0061] Advantageously, but not in a limiting manner, the adj ustment device 15 is configured to vary the distance between the level of powder material CP present in the unloading channel 9 and at least the upper conveyor device 5 or at least one component of the feeding assembly 2 , maintaining the same orientation of the components . In other words , in this case, the adj ustment device 15 is configured to move ( translate ) at least the upper conveyor device 5 or at least one component of the feeding assembly 2 .

[0062] Preferably, but not necessarily, the adj ustment device 15 is configured to move ( li ft or lower, in particular vertically, namely orthogonally to the support plane of the system 1 ) at least one element chosen from : the upper conveyor device 5 and / or at least one element of the feeding assembly 2 ( such as , for example , the respective feeding device ) and / or the entire feeding assembly 2 and / or a combination thereof , in particular by keeping the feeding of the powder material CP in the unloading channel 9 as much as possible tangent to the inclined panel 11A; in particular by moving ( li fting or lowering) the upper conveyor device 5 . Advantageously, but not in a limiting manner, the system 1 comprises a storage unit (memory) 16 , which is schematically shown in figure 1 . The storage unit 16 can be a physical storage unit or a cloud . The storage unit 16 is configured to store a plurality of parameters relating to the manufacturing of the ceramic item (namely, the so-called "recipe" ) . The stored or storable parameters comprise at least : a theoretical distance between the unloading device 8 and the upper conveyor device 5 or the feeding assembly 2 ; and the theoretical level of powder material CP in the unloading device 8 ; preferably, the parameters also comprise at least one further parameter chosen from : the type of said at least one powder material ( CP ) to be fed, the feeding speed of the powder material CP, the conveying speed of the conveyor devices 5 and 6 or a combination thereof . With reference to the theoretical level , it is linked to the deformation ( counterbalancing) of the pattern, namely of the streak / vein along the thickness , which has to be obtained in the area of the front wall 11 ( in particular, of the inclined panel 11A) of the unloading channel 9 . However, in reality, the actual level oscillates around the value of the theoretical level due to the ef fect of the powder material CP that can be fed, for example , with an actual flow rate di f ferent from the theoretical flow rate and, therefore , creates a local imbalance ( excess or shortage of powder material CP ) with respect to the theoretical level in that point . To this regard, the system 1 preferably comprises a processing unit 17 configured to compare the actual level of powder material CP in the unloading channel 9 detected by said at least one detection means 14 with the theoretical level and to cause the adj ustment device 15 to lower (vertically, namely orthogonally to the support plane of the system 1 ) said at least one element of the unloading system 1 , i f the actual detected level is higher than the theoretical level (without however drowning the lowered component in the powder material CP ) ; or to li ft (vertically, namely orthogonally to the support plane of the system 1 ) the upper conveyor device 5 and / or said at least one element of the feeding as sembly 2 , i f the actual detected level ( in particular, in all points along the direction Y) is lower than the theoretical level . To this regard, since the actual detected level typically is variable along the direction Y of the unloading channel 9 , the li fting ( in particular, vertically, namely orthogonally to the support plane of the system 1 ) is carried out so as to bring all the points in the unloading duct 9 to the same level ( in particular, to the highest detected level ) .

[0063] According to a further aspect of the invention, there is provided a method for the manufacturing of ceramic items , in particular ceramic slabs or tiles .

[0064] In particular, the manufacturing method is implemented by the system 1 described above .

[0065] The method comprises the fol lowing steps (non- exhaustive list ) of :

[0066] - conveying a powder material CP along a conveying path P by means of a conveyor assembly 4 ; the conveyor assembly 4 comprises an upper conveyor device 5 and a lower conveyor device 6 , which is arranged at a lower height than the upper conveyor device 5 , said upper conveyor device 5 and lower conveyor device 6 defining, between them, the conveying path P ;

[0067] - feeding the respective powder material CP to the upper conveyor device 5 by means of one or more feeding devices of a feeding assembly 2 ;

[0068] - providing an unloading device 8 comprising a front wall 11 and a rear wall 12 , which are opposite and spaced apart from one another and define , between them, the unloading channel 9 ; the unloading channel 9 has a proximal end EP, in the area of which the unloading channel 9 is configured to receive the powder material CP from the upper conveyor device 5 , and a distal end ED, which is opposite the proximal end EP and in the area of which the unloading channel 9 is conf igured to deliver the powder material CP to the conveyor device 6 ; wherein, in the area of the proximal end EP, at least a portion of the front wall 11 and at least a portion of the rear wall 12 converge to or diverge from one another ; and unloading the powder material CP from the upper conveyor device 5 into an unloading channel 9 of an unloading device 8 and feeding the powder material CP to the lower conveyor device 6 .

[0069] Advantageously, but not in a limiting manner, during said conveying step, the conveyor assembly 4 transports the powder material CP from the input station S I in a conveying direction A.

[0070] In particular, advantageously, but not in a limiting manner, the conveying step is carried out by means of a conveyor assembly 4 according to one of the variants described above .

[0071] Advantageously, but not in a limiting manner, the feeding step, which takes place at least partially simultaneously with the conveying step, is carried out by means of a feeding assembly 2 according to one of the variants described above and, therefore , the consideration set forth above apply .

[0072] Advantageously, but not in a limiting manner, the unloading step is carried out by means of an unloading assembly 3 according to one of the variants described above .

[0073] Advantageously, the unloading channel 9 comprises at least a portion o f the front wall 11 and at least a portion of the rear wall 12 , which converge towards one another in the conveying direction A of the material CP (namely, the cross section of the unloading channel 9 decreases in the conveying direction A of the powder material CP ) . The front wall 11 is provided with the panel 11A inclined at the angle a with respect to the panel 11B ( in particular, according to one of the variants discussed above for the system 1 ) and the unloading step comprises the step of feeding the powder material CP at least partially tangentially to the front wall 11 . Again, the considerations made above for the system 1 also apply to the method .

[0074] Preferably, but not necessarily, the method comprises the further step of detecting, by means of said at least one detection means 14 , in particular sensor (preferably analogue , more preferably of the capacitive or ultrasonic or laser kind) , the actual level of powder material CP in the unloading channel 9 of the unloading device 8 . In particular, the step of detecting the level is carried out by means of a detection device according to one of the variants described above . Therefore , again, the considerations made above for the system 1 also apply to the method . Preferably, the detection step takes place at least partially simultaneously with the unloading step .

[0075] Advantageously, but not in a limiting manner, in order to increase the accuracy of the level monitoring, the step of detecting the actual level comprises the sub-step of :

[0076] - providing at least two detection means 14 arranged, preferably spaced apart from one another, along a direction Y that extends transversely, in particular orthogonally, to the conveying direction A; and

[0077] - detecting the progress of the material level along the direction Y; and

[0078] - adj usting, by means of feedback control , the feeding of the powder material CP to the unloading device 8 along the direction Y .

[0079] Advantageously, but not in a limiting manner, the step of detecting comprises the sub-step of : detecting the actual level in the area of at least one of : a wall 11 or 12 of the unloading device 8 , in particular the rear wall 12 of the unloading device 8 ; and the upper conveyor device 5 .

[0080] Preferably, in order to further increase the quality of the ceramic item, the method comprises the further step of manually or semi-automatically or automatically displacing, by means of an adj ustment device 15 , the feeding position of the powder material CP in the unloading channel 9 , as a function of the actual level of powder material CP detected by said at least one detection means 14 . The step of displacing takes place at least partially simultaneously with the unloading step . Preferably, the step is carried out by the adj ustment device 15 according to one of the variants previously described with reference to the system 1 and, therefore , the considerations set forth above are also valid for the method .

[0081] Advantageously, but not in a limiting manner, the step of displacing the feeding position of the powder material CP in the unloading channel 9 comprises the sub-step of : automatically adj usting, in particular by means of feedback control , the position of the unloading point of the powder material CP in the unloading channel 9 , varying the distance , in particular the vertically measured dimension, between : the actual level of powder material CP present in the unloading channel 9 ; and at least the upper conveyor device 5 or at least one component of the feeding assembly 2 , as a function of the actual level of powder material CP detected by said at least one detection means 14 . Again, the considerations made above with reference to the system 1 also apply to the method .

[0082] Advantageously, but not in a limiting manner, the step of automatically displacing the position of the unloading point of the powder material ( CP ) in the unloading channel 9 comprises the sub-step of moving, in particular li fting or lowering (vertically, namely orthogonally to the support plane of the system 1 ) , at least one element chosen from :

[0083] - the upper conveyor device ; and / or

[0084] - an element comprised in the feeding assembly 2 , such as for example at least one feeding device ; and / or

[0085] - the entire feeding 2 ; and / or

[0086] - a combination thereof .

[0087] Again, the considerations made above with reference to the system 1 also apply to the method .

[0088] Preferably, the step of automatically displacing the position of the unloading point of the powder material CP in the unloading channel 9 comprises the sub-step of operating, at least partially independently of one another, a plurality of actuator devices of the adj ustment device 15 , so as to perform said variation of the distance . Again, the considerations made above with reference to the actuator devices of the system 1 also apply to the method .

[0089] Advantageously, but not in a limiting manner, the method comprises the further steps of :

[0090] - storing, by means of a storage unit 16 , a plural ity of parameters relating to the manufacturing of the ceramic item; the stored or storable parameters comprise at least : a theoretical distance between the unloading device 8 and the upper conveyor device 5 or the feeding assembly 2 ; and the theoretical level of powder material CP in the unloading device 8 ; preferably the parameters also comprise at least one further parameter chosen from : the type of said at least one powder material CP to be fed, the feeding speed of the powder material CP, the conveying speed of the conveyor devices or a combination thereof ; and

[0091] - comparing, by means of a processing unit 17 , the actual level of powder material CP in the unloading channel 9 detected by said at least one detection means 14 with said theoretical level ; and

[0092] - causing the adj ustment device 15 , by means of the processing unit 17 , to perform the steps of : lowering (vertically, namely orthogonally to the support plane of the system 1 ) said at least one element of the feeding assembly 2 , i f the actual detected level is higher than the theoretical level ; or li fting the upper conveyor device 5 and / or said at least one element of the feeding assembly 2 , i f the actual detected level , in particular in all points along the direction Y, is lower than the theoretical level .

[0093] In particular, advantageously, but not in a limiting manner, the storing step is carried out by means of a storage unit 16 as described above with reference to the system 1 .

[0094] In particular, advantageously, but not in a limiting manner, the step comparing and controlling is carried out by means of a processing unit 17 as described above with reference to the system 1 .

[0095] Advantageously, but not in a limiting manner, the method comprises a compaction step, which is carried out by means of a compaction device 13 . Again, the considerations made above with reference to the compacting device 13 al so apply to the method .

[0096] Advantageously, but not in a limiting manner, the method comprises , downstream of the compaction step, a firing step and / or a cutting step . According to a possible embodiment , the firing step and / or the cutting step are as di sclosed in patent application WO20221115547 ( filed by the Applicant ) .

[0097] The ceramic item manufacturing system 1 and the method for manufacturing ceramic items according to the invention have a plurality of advantages .

[0098] First of all , the system 1 and the method make it possible to obtain a ceramic item having a high graphic quality, in particular with reference to the pattern development (namely, the so-called "vein" in the thickness ) .

[0099] In particular, the system 1 and the method make it possible to obtain a pattern (namely, the so-called "vein" in the thickness ) that is substantially straight ( in particular, parallel to the thickness of the ceramic item itsel f ) .

[0100] Secondly, the system 1 and the method improve , by tangentially feeding to the inclined panel 11A, the control of the falling direction of the powder material CP . In particular, they make it possible to have a fall angle that extends mainly, in particular exclusively, along one single (univocal ) direction away from the panel 11A and transversely to the latter, thus avoiding dispersion, mixing and therefore crosscontamination between powder materials having characteristics ( for example, colour or physical characteristics ) that are different from one another .

[0101] In addition, the system 1 and the method, in particular if provided with the adjustment device 15, make it possible to obtain a synergistic effect, together with the inclined panel 11A, so as to obtain a further improvement in the quality of the ceramic product, in particular in terms of sharpness of the pattern of the layer of compacted powder material KP (and, hence, of a ceramic item obtained from said layer of compacted material KP) . This high sharpness of the pattern be obtained because of the adjustment device 15 that allows the powder material CP to reach the unloading channel 9 as close as possible to the free surface of the powder material CP present in the unloading device 8 . Therefore, the adjustment device 15 makes it possible to reduce the distance between the feeding device or the upper conveyor device 5 and the level of powder in the unloading device 8 to the ideal condition . Therefore, also thanks to the feedback control, it is possible to operate the individual actuators ( in particular, at least partially independently of one another) so as to vary the aforementioned distance, even during the operation of the system 1 itself .

[0102] In addition, the configuration of the unloading channel 9 described above or shown in the accompanying figures improves the flow of the powder material CP contained therein .

Claims

CLAIMS1. A system (1) for manufacturing ceramic items, in particular ceramic slabs or tiles, comprising:- a conveyor assembly (4) configured to convey a powder material (CP) along a conveying path (P) ; the conveyor assembly (4) comprises an upper conveyor device (5) and a lower conveyor device (6) , which is arranged at a lower height than the upper conveyor device (5) , said upper conveyor device (5) and lower conveyor device (6) defining, between them, the conveying path (P) ;- a feeding assembly (2) comprising one or more feeding devices, each configured to feed the respective powder material (CP) to the upper conveyor device (5) ; and an unloading assembly (3) comprises an unloading device (8) provided with an unloading channel (9) configured to receive the powder material (CP) from the upper conveyor device (5) and to feed it to the lower conveyor device (6) ; the unloading device (8) comprises a front wall (11) and a rear wall (12) , which are opposite and spaced apart from one another and define, between them, the unloading channel (9) ; the unloading channel (9) has a proximal end (EP) , in the area of which the unloading channel (9) is configured to receive the powder material (CP) from the upper conveyor device (5) , and a distal end (ED) , which is opposite the proximal end (EP) and in the area of which the unloading channel (9) is configured to deliver the powder material (CP) to the lower conveyor device (6) ; wherein, in the area of the proximal end (EP) , at least a portion of the front wall (11) and at least a portion of the rear wall (12) converge to one another along a conveying direction (A) of the powder material (CP) ; andwherein the front wall (11) of the unloading channel (9) comprises at least two flat panels (11A, 11B) arranged in succession to one another; wherein the first panel (11A) , which is arranged closer to the proximal end (EP) than the second panel (11B) , is inclined at a first angle (a) with respect to the second panel (11B) ; and wherein the upper conveyor device (5) is configured to feed the powder material in the area of the first panel (11A) of the front wall (11) at least partially tangentially to the front panel (11A) itself .

2. The system according to claim 1, wherein the upper conveyor device (5) is configured to feed the powder material (CP) in proximity of the surface of the first panel (11A) .

3. The system (1) according to claim 1 or 2, wherein the first angle (a) ranges from 3 to 30°, in particular from 5 to 15, more in particular is equal to 10°.

4. The system (1) according to any one of the preceding claims, wherein the portion of the rear wall (12) facing the panels (11A, 11B) comprises one single third panel (12A) , which is flat; and the third panel (12A) is arranged vertically or inclined at a second angle with respect to a vertical plane.

5. The system (1) according to any one of the preceding claims, comprising at least one, in particular a plurality of, detection means (14) , in particular preferably analogue sensors, more preferably of the capacitive or ultrasonic or laser kind, each configured to detect the actual level of powder material (CP) in the unloading channel (9) of the unloading device (8) .

6. The system (1) according to claim 5, wherein said at least two detection means (14) are arranged, preferablyspaced apart from one another, along a direction (Y) that extends transversely, in particular orthogonally, to the conveying direction (A) so as to detect the progress of the level of the material along the direction (Y) and to adjust, by means of feedback control, the feeding of the powder material (CP) to the unloading device (8) along the direction (Y) .

7. The system (1) according to claim 5 or 6, wherein said at least one detection means (14) is arranged in the area of at least one of: a wall (11, 12) of the unloading device (8) , in particular the rear wall (12) of the unloading device (8) ; and the upper conveyor device (5) .

8. The system (1) according to any one of the claims from 5 to 7, comprising an adjustment device (15) configured to manually or semi-automatically or automatically displace the feeding position of the powder material (CP) in the unloading channel (9) , as a function of the actual level of powder material (CP) detected by said at least one detection means ( 14 ) .

9. The system (1) according to claim 8, wherein the adjustment device (15) is configured to automatically displace, in particular by means of feedback control, the position of the unloading point of the powder material (CP) in the unloading channel (9) , varying the distance, in particular the vertically measured dimension, between: the actual level of powder material (CP) present in the unloading channel (9) ; and at least the upper conveyor device (5) or at least one component of the feeding assembly (2) , as a function of the actual level of powder material (CP) detected by said at least one detection means (14) .

10. The system (1) according to claim 9, wherein theadjustment device (15) is configured to move, in particular lift or lower, at least one element chosen from:- the upper conveyor device; and / or- an element included in the feeding assembly (2) , such as for example at least one feeding device (7) ; and / or- the entire feeding assembly (2) ; and / or- a combination thereof.

11. The feeding system (1) according to claim 8 or 10, wherein the adjustment device (15) comprises a plurality of actuator devices, which is operable at least partially independently of one another, so as to perform said variation of the distance.

12. The system (1) according to any one of the claims from 5 to 11, comprising: a storage unit (16) configured to store a plurality of parameters relating to the manufacturing of the ceramic item; the stored or storable parameters comprise at least: a theoretical distance between the unloading device (8) and the upper conveyor device (5) or the feeding assembly (2) ; and the theoretical level of powder material (CP) in the unloading device (8) ; preferably the parameters also comprise at least one further parameter chosen from: the type of said at least one powder material (CP) to be fed, the feeding speed of the powder material (CP) , the conveying speed of the conveyor devices or a combination thereof; and a processing unit (17) configured to compare the actual level of powder material (CP) in the unloading channel (9) detected by said at least one detection means (14) with said theoretical level; and to cause said adjustment device (15) to : lower said at least one element of the feeding assembly(2) , if the actual detected level is higher than the theoretical level; or lift the upper conveyor device (5) and / or said at least one element of the feeding assembly (2) , if the actual detected level, in particular in all points along the direction (Y) , is lower than the theoretical level.

13. A method for manufacturing ceramic items, in particular ceramic slabs or tiles, comprising the following steps of:- conveying a powder material (CP) along a conveying path (P) by means of a conveyor assembly (4) ; the conveyor assembly (4) comprises an upper conveyor device (5) and a lower conveyor device (6) , which is arranged at a lower height than the upper conveyor device (5) , said upper conveyor device (5) and lower conveyor device (6) defining, between them, the conveying path (P) ;- feeding the respective powder material (CP) to the upper conveyor device (5) by means of one or more feeding devices of a feeding assembly (2) ;- providing an unloading device (8) comprising a front wall (11) and a rear wall (12) , which are opposite and spaced apart from one another and define, between them, the unloading channel (9) ; the unloading channel (9) has a proximal end (EP) , in the area of which the unloading channel (9) is configured to receive the powder material (CP) from the upper conveyor device (5) , and a distal end (ED) , which is opposite the proximal end (EP) and in the area of which the unloading channel (9) is configured to deliver the powder material (CP) to the lower conveyor device (6) ; wherein, in the area of the proximal end (EP) , at least a portion of the front wall (11) and at least a portion of the rear wall (12)converge to one another in the conveying direction (A) of the powder material (CP) ; wherein the front wall (11) of the unloading channel (9) comprises at least two flat panels (11A, 11B) arranged in succession to one another; wherein the first panel (11A) , which is closer to the proximal end (EP) than the second panel (11B) , is inclined at a first angle (a) with respect to the second panel (11B) ; and- unloading the powder material (CP) from the upper conveyor device (5) into an unloading channel (9) of an unloading device (8) and feeding the powder material (CP) to the lower conveyor device (6) ; wherein the powder material (CP) is fed at partially tangentially to the first panel (11A) by means of the upper conveyor device (5) in the area of the first panel (11A) of the front wall (11) .

14. The method according to claim 13, wherein, during the step of unloading the powder material (CP) , the upper conveyor device (5) is configured to feed the powder material (CP) in proximity of the surface of the first panel (11A) .

15. The method according to claim 13 or 14, comprising the further step of detecting, by means of at least one detection means (14) , in particular preferably analogue sensors, more preferably of the capacitive or ultrasonic or laser kind, the actual level of powder material (CP) in the unloading channel (9) of the unloading device (8) .

16. The method according to claim 15, wherein the step of detecting the actual level comprises the sub-step of:- providing at least two detection means (14) arranged, preferably spaced apart from one another, along a direction (Y) that extends transversely, in particular orthogonally, to the conveying direction (A) ; and- detecting the progress of the material level alongthe direction (Y) ; and- adjusting, by means of feedback control, the feeding of the powder material (CP) to the unloading device (8) along the direction (Y) .

17. The method according to claim 15 or 16, wherein the step of detecting comprises the sub-step of: detecting the actual level in the area of at least one of: a wall (11, 12) of the unloading device (8) , in particular the rear wall (12) of the unloading device (8) ; and the upper conveyor device (5) .

18. The method according to any one of the claims from 15 to 17, comprising the further step of manually or semi- automatically or automatically displacing, by means of an adjustment device (15) , the feeding position of the powder material (CP) in the unloading channel (9) , as a function of the actual level of powder material (CP) detected by said at least one detection means (14) .

19. The method according to claim 18, wherein the step of displacing the feeding position of the powder material (CP) in the unloading channel (9) comprises the sub-step of: automatically adjusting, in particular by means of feedback control, the position of the unloading point of the powder material (CP) in the unloading channel (9) , varying the distance, in particular the vertically measured dimension, between: the actual level of powder material (CP) present in the unloading channel (9) ; and at least the upper conveyor device (5) or at least one component of the feeding assembly (2) , as a function of the actual level of powder material (CP) detected by said at least one detection means (14) .

20. The method according to claim 19, wherein the step of automatically displacing the position of the unloadingpoint of the powder material (CP) in the unloading channel (9) comprises the sub-step of moving, in particular lifting or lowering, at least one element chosen from:- the upper conveyor device; and / or- an element comprised in the feeding assembly (2) , such as for example at least one feeding device; and / or- the entire feeding assembly (2) ; and / or- a combination thereof.

21. The method according to any one of the claims from 18 to 20, wherein the step of automatically displacing the position of the unloading point of the powder material (CP) in the unloading channel (9) comprises the sub-step of operating, at least partially independently of one another, a plurality of actuator devices of the adjustment device (15) , so as to perform said variation of the distance.

22. The method according to any one of the claims from 15 to 21 and comprising the steps of: storing, by means of a storage unit (16) , a plurality of parameters relating to the manufacturing of the ceramic item; the stored or storable parameters comprise at least: a theoretical distance between the unloading device (8) and the upper conveyor device (5) or the feeding assembly (2) ; and the theoretical level of powder material (CP) in the unloading device (8) ; preferably the parameters also comprise at least one further parameter chosen from: the type of said at least one powder material (CP) to be fed, the feeding speed of the powder material (CP) , the conveying speed of the conveyor devices or a combination thereof; and comparing, by means of a processing unit (17) , the actual level of powder material (CP) in the unloading channel (9) detected by said at least one detection means (14) withsaid theoretical level; and causing the adjustment unit, by means of the processing unit (17) , to perform the steps of: lowering said at least one element of the feeding assembly (2) , if the actual detected level is higher than the theoretical level; or lifting the upper conveyor device (5) and / or said at least one element of the feeding assembly (2) , if the actual detected level, in particular in all points along the direction (Y) , is lower than the theoretical level.

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