Tablet press and method for rejecting and sampling tablets

Abstract

The rotary tablet press (1) a compression turret (2) rotating about an axis of rotation (X) and including a die table (3) provided with a number of dies (4) arranged to receive a compression target and produce a tablet (100); a conveying means (5) for conveying the tablets (100) produced by the dies (4) of the die table (3) into an outlet conduit (6); a reject / sampling system (7) configured to selectively direct preformed tablets (100) produced by the die (4) of the die table (3) into a reject conduit (8) or into a sampling conduit (9); The reject / sampling system (7) a first routing means (11) configured to act on individual tablets (100a) to be rejected to direct them from the die table (3) towards the reject conduit (8); a second steering means (12) configured to act on the individual tablets (100b) to be sampled to steer them from the die table (3) towards the sampling conduit (9); The first and second steering means (11, 12) are configured to act on the tablet (100) before it leaves the die table (3).

Description

[Technical Field]

[0001] The present invention relates to a press suitable for producing tablets, lozenges and pills for pharmaceutical, food and chemical applications, in particular a rotary press provided with a system for rejecting or sampling the tablets produced, and a method for rejecting or sampling the tablets produced in the press. [Background technology]

[0002] Known rotary presses include a compression turret formed by a die table or die plate that rotates about a vertical axis and is provided with a plurality of dies, i.e., through cavities. The dies are angularly distributed around the periphery of the table, equidistant from one another, and positioned to receive a supply of powder or granules at dedicated loading points. The turret also includes a plurality of upper and lower punches. The upper and lower punches correspond in pairs to each die and are moved linearly and vertically, coaxially with the dies, by cams and compression rollers during rotation of the turret.

[0003] The lower punch together with the die forms a suitable seat or filling chamber capable of receiving the object to be compressed at the filling point.

[0004] At the subsequent compression point, the upper and lower punches are moved by compression rollers to compress the object introduced into the die, thereby producing a tablet. The tablet is then extracted from the die at the table using the lower punch, appropriately lifted, and conveyed through an exit chute corresponding to the exit point. During the rotation of the compression turret, which rotates in a generally continuous motion, various tablet manufacturing processes are carried out.

[0005] The exit chute is usually equipped with a reject system that routes produced tablets that do not meet production requirements such as size, hardness, porosity, and weight into an appropriate reject conduit. These parameters can be detected, for example, by measuring the compression force exerted by the punches in the single die, the height of the object fed into the die, or the mass of the tablet using microwave sensors or based on magnetic resonance techniques, or by directly measuring the tablet weight using electronic scales or load cells.

[0006] The reject system typically includes a movable routing element that is mechanically movable by an electrical or pneumatic actuator into an operative position, thereby directing rejected tablets into a reject conduit, while legitimate tablets are instead conveyed into the main conduit of the exit chute.

[0007] Similarly, some known presses include a sampling system, typically at the exit chute, that routes a batch or sample of the produced tablets into a sampling conduit, for example, for thorough inspection and extensive quality control.

[0008] For this purpose, the sampling system includes a dedicated movable routing element that can be mechanically moved into an active position by an electrical or pneumatic actuator, thereby routing the tablet to be sampled into the appropriate conduit.

[0009] Known reject and sampling systems have the disadvantage that when a tablet press operates at high speed (i.e., the compression turret rotates at high speed), they perform cumulative rejection and sampling, i.e., rejection and sampling of multiple tablets in succession, because the slow mechanical movement of the movable routing element does not allow the routing element to select and route tablets one by one, i.e., perform so-called single reject and sampling.

[0010] However, single-type sampling is very useful and important because it allows, for example, sampling and analyzing only specific tablets exiting a press, for example, tablets produced by a specific pair of punches out of multiple pairs of (upper and lower) punches, typically to verify whether the specific pair of punches is operating normally.

[0011] U.S. Patent Application Publication No. 2010 / 094449 discloses a system for rejecting tablets produced in a rotary press. The system includes a discharge nozzle for separating defective tablets. The discharge nozzle is supplied with compressed gas through a supply line. The supply line has an inlet end for connection to a compressed gas source and an outlet end communicating with the discharge nozzle. The supply line is provided with a control valve controlled by a control unit to open the supply line if a defective tablet is detected by the control unit. The supply line is provided with a sensor located between the control valve and the inlet end of the supply line, suitable for detecting a parameter indicative of gas flow through the control valve. The control unit is configured to generate an error signal if the control valve malfunctions.

[0012] U.S. Patent Application Publication No. 2017 / 080662 discloses a rotary tablet press. The tablet press includes a table rotatable about a vertical axis of rotation and provided with a die having holes, whereby tablets are produced through the holes using a punch pair. The press includes at least one filling station, at least one pressing station, and at least one tablet outlet for extracting tablets produced by the rotary press. A rejection device is coupled to the outlet and can feed tablets to a first channel as individual tablets or to a second channel as a tablet flow, based on a control signal. To increase production at the outlet, a weighing device is coupled to the weighing cell and can feed tablets from the first channel to the weighing device via a feed channel.

[0013] U.S. Patent Application Publication No. 2021 / 221085 discloses a reject chute for a tablet making machine and a method for selecting tablets made by the tablet making machine. The reject chute includes a channel through which produced tablets are guided and / or sorted, the channel being arranged on two sides. The tablet sorting is performed using sorting devices arranged in a line. Each sorting device includes two bars, preferably designated as a sorting bar and a separating bar. The sorting bar includes a linear drive, which is connected to the separating bar by a vibrating lever. When the sorting bar moves upward from a resting position to a sorting position, the separating bar automatically descends, opening the opening of the sorting channel. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] US Patent Application Publication No. 2010 / 094449 [Patent Document 2] US Patent Application Publication No. 2017 / 080662 [Patent Document 3] U.S. Patent Application Publication No. 2021 / 221085 Summary of the Invention [Problem to be solved by the invention]

[0015] One of the objects of the present invention is to improve known tablet presses, in particular rotary presses, which are provided with a system for rejecting and sampling the tablets produced.

[0016] A further object is to provide a press that is capable of selectively rejecting or sampling each produced tablet accurately and precisely, in particular performing single rejection and sampling.

[0017] A further object is to provide a press provided with an efficient and accurate reject / sampling system which is simple and economical to assemble.

[0018] Yet another object is to provide a method for rejecting and sampling tablets produced by a press, and in particular a method for selectively rejecting or accurately and precisely sampling each produced tablet to achieve single rejection and sampling. [Means for solving the problem]

[0019] A first aspect of the present invention provides a tablet press as set forth in claim 1.

[0020] A second aspect of the present invention provides a method for rejecting and sampling tablets from a press as set forth in claim 7. [Brief explanation of the drawings]

[0021] The invention may be better understood and put into practice with reference to the accompanying drawings which show exemplary and non-limiting embodiments. [Figure 1] FIG. 1 is a schematic and simplified plan view of a rotary tablet press of the present invention during the production process, the rotary tablet press being provided with a reject / sampling system for the tablets produced. [Figure 2] FIG. 2 is a partial plan view of the press of FIG. 1 with the reject / sampling system in sampling operation. [Figure 3] FIG. 2 is a partial plan view of the press of FIG. 1 with the reject / sampling system in a reject operation. [Figure 4] 2 is a partial plan view of the press of FIG. 1 during a reject operation in the first step of the reject / sampling system adjusting the press. DETAILED DESCRIPTION OF THE INVENTION

[0022] 1 to 4 show diagrammatically a rotary tablet press 1 according to the present invention. The tablet press 1 comprises a compression turret 2 which rotates about a rotation axis X, which is in particular vertical, and which comprises a die table 3 provided with a plurality of dies 4 or through cavities arranged to receive material to be compressed and produce tablets 100. The dies 4 are spaced apart from one another at angles along the periphery of the die table 3.

[0023] The press 1 further includes a plurality of lower and upper punches and a filling station. The lower and upper punches are of a known type and are not shown in the figure, and are paired with each die. The filling station is adapted to fill a filling cavity formed by the lower punch closing the lower part of the die 4 with the target material. A driving means, e.g., a cam type, is provided to move the lower punch and / or the upper punch within each die 4 to compress the target material into tablets.

[0024] The press 1 further includes a conveying means 5 and a reject / sampling system 7. The conveying means 5 is for conveying tablets 100 produced by the dies 4 of the die table 3 into an outlet conduit 6. The reject / sampling system 7 is configured to selectively route preformed tablets 100 produced by the dies 4 into a reject conduit 8 or a sampling conduit 9.

[0025] In particular, the reject / sampling system 7 includes a first routing means 11 and a second routing means 12. The first routing means 11 is configured to act on individual tablets 100a to be rejected, directing them from the die table 3 towards the reject conduit 8. The second routing means 12 is separate from the first routing means 11 and is configured to act on individual tablets 100b to be sampled, directing them from the die table 3 towards the sampling conduit 9. More precisely, the first and second routing means 11, 12 are configured to act on one tablet at a time to perform the rejection or sampling of the individual tablet.

[0026] In the illustrated embodiment, the first and second directional determining means 11, 12 each comprise a compressed air supply device of known type suitable for emitting a respective blow or jet of compressed air capable of striking one tablet 100a to be rejected at a time and directing one tablet 100b to be sampled at a time as the tablets are extracted from each of the dies 4 of the die table 3.

[0027] The outlet conduit 6 receives the tablet 100 extracted from the die 4 (eg, by appropriately raising the lower punch) and is, for example, disposed approximately radially of the die table 3 .

[0028] The conveying means 5 includes a shaped, curved guide element 15 which is configured to contact the tablet 100 extracted from the die 4 and slide over the upper surface of the die table 3 to guide the tablet 100 into the outlet conduit 6.

[0029] The reject conduit 8 and the sampling conduit 9 are arranged side by side and parallel to the outlet conduit 6 and extend from the die table 3. The reject conduit 8 is arranged, for example, between the sampling conduit 9 and the outlet conduit 6. The reject conduit 8, the sampling conduit 9 and the outlet conduit 6 are inclined downwards, for example, to allow tablets to easily slide down by gravity.

[0030] The first path determination means 11 is arranged above the die table 3 and upstream of the outlet conduit 6 in the forward direction of the tablets exiting the die 4, and in particular, opposite the mouth of the reject conduit 8, so as to direct each of the tablets 100a to be rejected extracted from the die 4 and push them into the reject conduit 8.

[0031] Similarly, the second path determining means 12 is positioned above the die table 3 and upstream of the outlet conduit 6, particularly opposite the mouth of the sampling conduit 9, so as to direct each tablet 100b to be sampled extracted from the die 4 and push it into the sampling conduit 9.

[0032] In particular, the second path determining means 12 is arranged on the die table 3 and upstream of the first path determining means 11 with respect to the advance direction of the tablet.

[0033] The press 1 may further include sensor means arranged adjacent the first 11 and second 12 path determining means and configured to detect the passage, and in particular the presence, of a tablet 100 in front of the first 11 and second 12 path determining means.

[0034] A control unit 10 is provided. The control unit 10 is connected to the first routing means 11 and the second routing means 12 and is configured to selectively activate the routing means 11 or the second routing means 12 when a tablet to be rejected or a tablet to be sampled is on the die table 3 and arrives before the first routing means 11 or the second routing means 12.

[0035] The control unit 10 is, for example, a control unit that controls the operation of the entire press 1. For example, the control unit 10 may be connected to sensor means suitable for detecting the compression force exerted by the punch inside the die 4 and / or other parameters of the tablets 100, such as size, hardness, porosity, weight, etc., that enable the control unit 10 to identify manufactured tablets 100 that do not meet production requirements, i.e. tablets 100a that should be rejected.

[0036] In particular, the control unit 10 identifies tablets 100a to be rejected and the dies 4 of the die table 3 that contain the tablets 100a to be rejected, so that the control unit 10 can identify such tablets as they exit the die table 3 and route them into the reject conduit 8 or into the sampling conduit 9 by the reject / sampling system 7.

[0037] The reject / sampling system 7 further includes a third routing means 13 configured to route a certain number of tablets 100a to be rejected from the outlet conduit 6 towards the reject conduit 8, for example in an initial step of adjusting the press 1 when the produced tablets do not yet meet production requirements.

[0038] The third path determining means 13 includes, for example, a path determining element that can be moved to an operating position A to direct a certain number of tablets 100a to be rejected from the outlet conduit 6 towards the reject conduit 8. In particular, the path determining element 13 is inserted into a wall separating the outlet conduit 6 from the reject conduit 8 and rotates in the operating position A. In the operating position A, the path determining element 13 is inserted into the outlet conduit 6 to stop the progress of the tablets 100a to be rejected sliding in the outlet conduit 6 and direct the tablets to be rejected.

[0039] The navigation element 13 is rotated by a drive means (not shown) of known kind, for example an electric drive means or a pneumatic drive means.

[0040] The operation of the rotary press 1 of the present invention includes extracting the tablet 100 from the die 4 of the die table 3 and transporting the tablet 100 into the outlet conduit 6 using the guide element 15 of the transport means 5.

[0041] When a tablet 100a to be rejected, which has been stored by the control unit 10 and extracted from each die 4, moves on the die table 3 and reaches in front of the first path determination means 11, the first path determination means is operated by the control unit 10 to direct the tablet to be rejected and push it into the reject conduit 8.

[0042] Similarly, when a tablet 100b to be sampled, which has been stored by the control unit 10 and extracted from each die 4, moves on the die table 3 and arrives in front of the second path determination means 12, the second path determination means is activated to direct the tablet 100b to be sampled and push it into the sampling conduit 9.

[0043] It should be noted that the first navigating means 11 and the second navigating means 12 act on the tablet 100 before it leaves the die table 3 .

[0044] Thus, the press 1 of the present invention is particularly capable of performing single rejection and sampling by selectively rejecting or sampling the tablets produced individually.

[0045] More precisely, the use of the path determining means 11, 12, in particular pneumatic blow compressed air, allows for a simple and economical reject / sampling system 7 which operates on one tablet at a time and is therefore able to perform single rejects and samples of tablets 100 in an accurate and reliable manner, even when the press 1 is operating at high speeds.

[0046] Thus, when sampling, it is possible to selectively sample only preformed tablets, even if they are separated from each other in the die table 3 by other tablets that should not be sampled. For example, it is possible to sample only all tablets produced by a particular pair of compression punches, in order to precisely and accurately control their operation.

[0047] The method of the present invention for rejecting and sampling tablets, pills, lozenges, etc. produced by press 1 comprises: - conveying tablets 100 produced by the dies 4 of the die table 3 of the compression turret 2 of the press 1 into an outlet conduit 6; - using the first path determining means 11 to direct the tablets 100a produced by the die 4 to be rejected one by one from the die table 3 towards the reject conduit 8; - using a second routing means 12 different from the first routing means 11 to route the tablets 100b produced by the die 4 to be sampled one by one from the die table 3 towards the sampling conduit 9; The first and second navigating means 11 , 12 act on the tablet 100 before it leaves the die table 3 .

[0048] The step of steering the individual tablets 100a to be rejected is carried out using a jet of compressed air emitted by the first steering means 11.

[0049] The step of steering the individual tablets 100b to be sampled is carried out using a jet of compressed air emitted by the second steering means 12.

[0050] According to this method, the steps of routing the individual tablets 100a to be rejected and the individual tablets 100b to be sampled are performed when the tablets to be rejected or the tablets to be sampled are on the die table 3 and arrive before the first routing means 11 or the second routing means 12, respectively.

[0051] The method further includes, in particular in the initial step of adjusting the press 1, a step of using a third path determination means 13 to direct the plurality of tablets 100a to be rejected from the outlet conduit 6 towards the reject conduit 8.

[0052] In particular, the routing elements of the third routing means 13 are used to route the plurality of tablets 100a to be rejected from the outlet conduit 6 towards the reject conduit 8. Thus, the method of the present invention can selectively reject or sample tablets produced by and extracted from the die table 3 of the press 1 one by one in an accurate and precise manner, thereby achieving single rejection and sampling.

Claims

1. A rotary tablet press (1), a compression turret (2) rotating about an axis of rotation (X) and including a die table (3) provided with a number of dies (4) arranged to receive the objects to be compressed and to produce tablets (100); - conveying means (5) for conveying the tablets (100) produced by the dies (4) of the die table (3) into an outlet conduit (6); a reject / sampling system (7) configured to selectively route preformed tablets (100) produced by the dies (4) of the die table (3) into a reject conduit (8) or into a sampling conduit (9); The reject / sampling system (7) comprises: a first routing means (11) configured to act on individual tablets (100a) to be rejected to direct them from the die table (3) towards the reject conduit (8); a second routing means (12) separate from the first routing means (11) and configured to act on individual tablets (100b) to be sampled to direct them from the die table (3) towards the sampling conduit (9); The rotary tablet press (1) is characterized in that the first and second path determining means (11, 12) are configured to act on the tablet (100) before it leaves the die table (3).

2. The first path determination means (11) and the second path determination means (12) each include a compressed air supply device; 2. The rotary tablet press (1) of claim 1, wherein the compressed air supply device is adapted to emit compressed air blows that can strike one tablet (100a) to be rejected at a time and direct it towards one tablet (100b) to be sampled at a time.

3. Further comprising a control unit (10), The control unit (10) It is connected to at least the first route determination means (11) and the second route determination means (12), activating the first path determining means (11) when the tablet to be rejected is on the die table (3) and arrives in front of the first path determining means (11); 3. A rotary tablet press (1) according to claim 1 or 2, configured to activate the second path determining means (12) when the tablet to be sampled is on the die table (3) and arrives in front of the second path determining means (12).

4. The reject / sampling system (7) further comprises a third routing means (13); 3. A rotary tablet press (1) according to claim 1 or 2, wherein the third path determining means (13) is configured to direct a certain number of tablets (100a) to be rejected from the outlet conduit (6) towards the reject conduit (8).

5. The third route determination means (13) includes a route determination element, 5. The rotary tablet press (1) of claim 4, wherein the path determining element is capable of moving to an operating position (A) to direct the plurality of tablets (100a) to be rejected from the outlet conduit (6) toward the reject conduit (8).

6. 3. The rotary tablet press (1) according to claim 1 or 2, wherein the reject conduit (8) and the sampling conduit (9) are arranged side by side and parallel to the outlet conduit (6) and extend from the die table (3).

7. 3. A rotary tablet press (1) according to claim 1 or 2, wherein the first and second path determining means (11, 12) are arranged above the die table (3) and upstream of the outlet conduit (6) in relation to the direction of tablet advancement.

8. 3. A rotary tablet press (1) according to claim 1 or 2, wherein the second path determining means (12) is arranged on the die table (3) and upstream of the first path determining means (11) in the direction of tablet advancement.

9. The reject / sampling system (7) further includes a third path determining means (13), 3. A rotary tablet press (1) according to claim 1 or 2, wherein the third path determining means (13) is configured to direct a certain number of tablets (100a) to be rejected from the outlet conduit (6) towards the reject conduit (8) in a first step of adjusting the tablet press (1).

10. A method for rejecting and sampling tablets, pills, lozenges produced on a rotary tablet press (1), comprising: - conveying tablets (100) produced by dies (4) mounted on a die table (3) of a compression turret (2) of said tablet press (1) into an outlet conduit (6); - using a first routing means (11) to route the rejected tablets (100a) produced by the die (4) one by one from the die table (3) towards the reject conduit (8); - using a second routing means (12) separate from the first routing means (11) to route the tablets (100b) produced by the die (4) to be sampled one by one towards the sampling conduit (9), The method, wherein the first and second navigating means (11, 12) act on the tablet (100) before it leaves the die table (3).

11. 11. The method according to claim 10, wherein the step of steering each tablet (100a) to be rejected is performed using compressed air blows emitted by the first steering means (11).

12. 12. The method according to claim 10 or 11, wherein the step of steering the individual tablets (100b) to be sampled is performed using compressed air blows emitted by the second steering means (12).

13. the step of routing each of the tablets (100a) to be rejected is carried out when the tablet to be rejected is on the die table (3) and arrives before the first routing means (11); 12. The method according to claim 10 or 11, wherein the step of directing each tablet (100b) to be sampled is performed when the tablet to be sampled is on the die table (3) and arrives before the second routing means (12).

14. A method as described in claim 10 or 11, further comprising a step of using a third path determination means to direct a plurality of tablets (100a) to be rejected from the outlet conduit (6) toward the reject conduit (8).

15. A method as described in claim 10 or 11, further comprising, in the first step of adjusting the tablet press (1), using a third path determination means to direct a plurality of tablets (100a) to be rejected from the outlet conduit (6) toward the reject conduit (8).

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