Method for the trial pressing of pellets in a rotary press and rotary press

Abstract

A method for the test pressing of compacts (48) in a rotary press, comprising a rotationally driven rotor with upper and lower press punches (14, 16), an upper and lower punch guide (18, 20) for the upper and lower press punches (14, 16), and a die plate (10) between the punch guides (18, 20), wherein the upper and lower press punches (14, 16) interact with receptacles (12) of the die plate (10) during production operation of the rotary press, further comprising a filling device (26) in which material to be pressed is filled into the receptacles (12) during production operation of the rotary press, further comprising a pressure device (34) with upper and lower pressure tools which interact with the upper and lower press punches (14, 16) during production operation of the rotary press, so that they press material located in the receptacles (12) into compacts, characterized in thatthat the procedure comprises the following steps: , • material to be pressed is filled into a receptacle (12), • a pair of punches comprising an upper and lower press punch (14, 16) assigned to the holder (12) of the die plate (10) is brought into a test pressing position in which the upper press punch (14) is located in an area of ​​action of an upper test pressing tool (36, 40, 54) of a test pressing device of the rotary press and the lower press punch (14) is located in an area of ​​action of a lower test pressing tool (38, 42, 56) of the test pressing device, • the upper and lower test pressing tools (36, 40, 54, 38, 42, 56) are moved towards one another by means of a test pressing drive (58) of the test pressing device, so that the upper pressing punch (14) and the lower pressing punch (16) are pressed towards one another by the upper and lower test pressing tools (36, 40, 54, 38, 42, 56) in the receptacle (12) of the die plate (10) in order to press the material filled into the receptacle (12) into a test compact (48).

Description

[0001] The invention relates to a method for the test pressing of compacts in a rotary press, comprising a rotatingly driven rotor with upper and lower press punches, an upper and lower punch guide for the upper and lower press punches and a die plate between the punch guides, wherein the upper and lower press punches interact with receptacles of the die plate during production of the rotary press, further comprising a filling device in which material to be pressed is filled into the receptacles during production of the rotary press, further comprising a pressure device with upper and lower pressure tools which interact with the upper and lower press punches during production of the rotary press so that they press material located in the receptacles into compacts.The invention also relates to a rotary press, comprising a rotationally driven rotor with upper and lower press rams, an upper and lower ram guide for the upper and lower press rams and a die plate between the ram guides, wherein the upper and lower press rams interact with receptacles of the die plate during production of the rotary press, further comprising a filling device in which material to be pressed is filled into the receptacles during production of the rotary press, further comprising a pressure device with upper and lower pressure tools which interact with the upper and lower press rams during production of the rotary press so that they press material located in the receptacles into compacts.

[0002] Trial pressings are carried out, for example, to determine the optimal setting parameters of the rotary press for producing pellets in production for materials that are to be newly compressed. The pellets can particularly be tablets. In order to press a tablet with the least possible product usage during a trial pressing, individual pressings are desired, in which, for example, only one pellet is produced. Rotary presses are commonly used for the production of pellets in large quantities. To achieve the required pressing force to produce the pellet, the press rams move relative to a guide geometry of a pressing device, for example comprising upper and lower pressure rollers or pressure wedges. The pressing speed and pressure holding time are determined by the rotor rotation speed, the guide geometry and the punch head shape of the press rams.In principle, the guide geometry can be influenced by various measures. For example, guide curves for the press rams can be adjusted. These control the axial movement of the press rams as they rotate with the rotor. Furthermore, with rotary presses, it is possible to influence the pressing force by slightly axially adjusting the pressure tools, for example the pressure rollers or the pressure wedges. If the opposing upper and lower pressure tools are moved closer together, the compact is compressed more strongly during the pressing process and has a lower web height. This results in a higher pressing force. Naturally, changing the distance between the upper and lower pressure tools influences the pressing of subsequent compacts. In a rotary press, for example, the web height of the compact is an adjustable value.The hardness of the compact and the force required to move it through the guide geometry of the rotary press, especially the pressure device, are determined from this. Press force control is also possible, in which the web height is adjusted during operation based on the measured press force.

[0003] Linear presses or single-punch presses are also known for trial pressing and are typically used to produce small batches of tablets. One area of ​​application is the research and development of new medications and product formulations. To compress the tablet, opposing dies are moved toward each other. This can be achieved by axially moving both dies or just one of them. The movement is controlled by a linear drive, such as a spindle drive. With this type of single-punch press, both the web height of the tablet and the pressing force can be set as target values. The other value results from this.

[0004] If test pressings with a defined press force curve are to be carried out in a rotary press intended for regular production operation, the distance between the pressing tools must first be determined, from which the desired press force results. In a rotary press, this is only possible using a trial and error process in which a compaction height is first set, the resulting press force is evaluated, and the compaction height is adjusted. These steps must be repeated until the desired press force is achieved. This requires a considerable amount of material to be pressed. The adjustment of the guide geometry, in particular the distance between opposing press tools, takes place very slowly in a rotary press and can only be controlled within very limited limits. The distance can also be adjusted using the press force control explained above.The adjustment of the distance between the punches, which results from the press force, takes place very slowly in many control steps. Apart from this, the specified distance position of the pressing tools is approached by adjustment drives at a constant speed and cannot be freely controlled. The adjustment of opposing pressing tools can only adjust the press force within narrow limits and takes place while the rotary press is in operation. This means that an average value is recorded for one or more compacts. This value then serves as the basis for readjusting the distance between the pressing tools. During this readjustment, further compacts are produced that were not manufactured under the desired conditions and therefore constitute rejects.

[0005] Linear presses, on the other hand, are not suitable for producing large quantities of compacts. Another disadvantage in terms of effort is that a separate test press must be provided in addition to the rotary press intended for production. Furthermore, the data generated in this way cannot be directly transferred to the rotary press intended for production, particularly due to different press components and other parameters, such as press chamber ventilation or machine spring suspension. The generated data must therefore be adapted to the production press. For this adaptation, it is regularly necessary to carry out further test pressings on the rotary press intended for production, which further increases the effort.

[0006] DE 103 19 024 B3 discloses a method for the trial compression of tablets in a rotary tabletting machine, which is carried out in a rotary press intended for regular production operation. A pair of punches selected for a single compression is automatically moved to a filling position and, with the filling assembly at least partially removed and the rotor at a standstill, a die or a limited number of dies are filled with material. The rotor is then set in rotation and accelerated so that it reaches the desired production speed in the compression station of the rotary press. After one revolution, the rotor is stopped again in the filling position. During the rotor's rotation, signals or signal curves from the measuring points are recorded and transferred to a computer for display and evaluation. The advantage of this method is that no separate test press is required for the test compression.This reduces the effort. At the same time, the data obtained during the test pressing can be used directly and essentially without adjustment, as it was already generated on the rotary press intended for production operation. This also reduces the effort. By filling only one or a few dies with material, the required product input for the test pressing can be kept low. However, the land height of the tablet produced must be estimated during the first test pressing based on the fill quantity in the die, which means that an initially unknown press force is generated at the printing station. The press force desired for the respective product must therefore be determined accordingly in the course of a series of test pressings. This again increases the effort and product input.

[0007] From US 5517871 A a method is known for simulating a desired tablet pressing situation using a test press which simulates the compression of a tableting material into a tablet in the preferred tablet press, such that the preferred tablet press is controlled to achieve measured movements detected in the test press.

[0008] DE 10 2005 030 311 B3 describes a method for pressing tablets, in particular for test pressing, wherein at least one die of a die table is filled with a mass to be pressed and the mass to be pressed is subjected to a pressing force at at least one pressure station with a lower punch and an upper punch and the pressed tablet is ejected from the at least one die.

[0009] DE 10 2007 052 ​​552 A1 describes a method and a device for determining control and regulation parameters for tablet presses using a laboratory tablet press, which is also intended to be suitable for the production of small batches of tablets. Based on the prior art explained, the object of the invention is to provide a method and a rotary press of the type mentioned at the outset, which enable a test pressing to be carried out reliably and with little effort in order to adjust a rotary press for a production operation.

[0010] The invention solves the problem by the independent claims 1 and 11. Advantageous embodiments can be found in the dependent claims, the description and the figures.

[0011] For a method of the type mentioned above, the invention solves the problem by the following steps: • material to be pressed is filled into a receptacle, • a pair of punches consisting of an upper and lower press punch assigned to the holder of the die plate is brought into a test pressing position in which the upper press punch is located in an area of ​​influence of an upper test pressing tool of a test pressing device of the rotary press and the lower press punch is located in an area of ​​influence of a lower test pressing tool of the test pressing device, • the upper and lower test pressing tools are moved towards each other by means of a test pressing drive of the test pressing device, so that the upper pressing punch and the lower pressing punch are pressed towards each other by the upper and lower test pressing tools in the holder of the die plate in order to press the material filled into the holder into a test compact.

[0012] For a rotary press of the type mentioned at the outset, the invention solves the problem in that the rotary press further comprises a test pressing device, comprising an upper test pressing tool and a lower test pressing tool, wherein for a test pressing the upper test pressing tool interacts with an upper press punch assigned to a receptacle of the die plate and the lower test pressing tool interacts with a lower press punch assigned to the same receptacle, and comprising a test pressing drive which moves the upper test pressing tool and the lower test pressing tool towards one another for a test pressing, so that the upper press punch and the lower press punch are pressed towards one another by the upper and lower test pressing tools in the receptacle of the die plate for pressing material filled into the receptacle to form a test compact.

[0013] The rotary press according to the invention or the rotary press used in the method according to the invention is a rotary press intended for the regular production of pressed products, in particular tablets, made of, in particular, powdered material. The rotary press comprises, in a manner known per se, a rotor with a plurality of upper and lower press punches, each paired with a receptacle or cavity of a die plate. The receptacles can be designed as direct bores in the die plate. However, they can also be formed in sleeve-like inserts that are inserted into correspondingly larger receptacles in the die plate. During operation of the rotary press, the upper and lower press punches rotate together with the die plate, with their axial movement controlled by control cams and guided by upper and lower punch guides.The control cams usually interact with the punch heads of the press rams. As it rotates, the die plate passes through various devices on the rotary press during production: a filling device, in which the powder material to be pressed is filled into the die plate's receptacles, and a pressure device, in which the upper and lower press rams are pressed into the receptacles by upper and lower pressure tools, for example upper and lower pressure rollers, to compress the powder material into pellets, such as tablets. The pressure device can have upper and lower pre-pressure tools, in particular pre-pressure rollers, as well as upper and lower main pressure tools, in particular main pressure rollers. As an alternative to pressure rollers, pressure wedges are also possible.Following the pressure device, the upper press rams are moved upwards out of the holders during production, and the compacts produced in the holders are pushed onto the top side of the die table by the lower press rams. For this purpose, ejector cams are provided which move the lower press rams upwards. The compacts are then stripped from the die table, for example by a stripper, into an outlet of the rotary press, from where they are fed for further processing. The control cams usually also include dosing cams which, when the upper press ram is moved upwards out of the respective holder, move the lower press ram into a predetermined position, partially inserted into the holder. In this dosing position, the lower press ram forms a base for the respective holder and thus defines the fill level of the material filled into the holder.

[0014] As already explained, the rotary press used according to the invention is a rotary press intended for regular production operation. It can be adapted to carry out the method according to the invention, as explained in more detail below. In particular, components of the rotary press, for example, the upper and lower press rams and / or the filling device, can be disassembled before starting a test press run.

[0015] According to the invention, the rotary press has a test pressing device comprising an upper test pressing tool and a lower test pressing tool. In the method according to the invention, a punch pair consisting of an upper and an opposite lower press punch, which is assigned to a receptacle of the die plate, is brought into a test pressing position in which the upper press punch is located within the action zone of the upper test pressing tool and the lower press punch is located within the action zone of the lower test pressing tool. The punch pair can be brought into the test pressing position by rotating the rotor into a position in which the punch pair is within the action zone of the test pressing tools. Before, simultaneously with, or after the punch pair is brought into the test pressing position, material to be pressed is filled into the receptacle to which the punch pair is assigned.The holder can be filled manually, for example. The holder can be filled to its maximum capacity. Any excess material can be scraped off the top of the die table. It is also possible to only partially fill the holder so that a previously weighed amount can be safely and completely absorbed by the holder and then pressed. The upper and lower test pressing tools are then moved towards one another by a test pressing drive of the test pressing device so that the upper and lower test pressing tools initially come into contact with the upper and lower press punches, respectively, and the upper and lower press punches are pressed together in such a way that the pair of punches presses the material in the holder into a test compact.It is possible for the upper and lower test compression tools to move both the upper compression ram axially toward the lower compression ram, and for the lower compression ram to move axially toward the upper compression ram. However, it is also possible for only one of the compression rams to be moved axially and pressed against the other compression ram, which is axially fixed by the respective test compression tool. As with a regular compression of a compact, the compression rams are positioned with their ram tips within the holder and compress the material between their ram tips to form the compact, for example, a tablet.

[0016] After the test pressing is completed, the upper and lower test pressing tools can be moved apart using the test pressing drive, and the produced test compact can be removed. For this purpose, the rotor can be rotated, for example, to an ejection position, in which the upper press ram is moved upwards out of the holder and the produced test compact is pushed onto the top of the die plate by the lower press ram.

[0017] The rotary press according to the invention thus provides a test press device that replicates the properties of a linear press for individually pressing compacts in the environment of a rotary press intended for regular production operation. The test press device with the test press drive enables individually controlled and thus dynamic driving of the test press tools towards each other, resulting in the pressing of the material into the test compact. Due to the possible individual control of the test press drive, optionally automated according to previously selected parameters or trajectories, a regular pressing process in the rotary press can be reliably and precisely simulated. The test press drive can also be controlled during the test pressing and fulfills the advantageous properties of a linear press explained above without incurring its disadvantages.As already mentioned, the rotor's rotary drive can be used to move the pair of punches into the test press position. The rotary drive can also be used to lock the press punches during the test press, preventing them from moving radially during the pressing process.

[0018] By integrating a test press device for individual pressings into a rotary press intended for production, the acquisition costs and personnel training required for a separate linear press can be avoided. The typically limited assembly space in laboratories where such presses are frequently operated is saved. The test press environment within the rotary press is the same as that used for subsequent production operation. This ensures that influences such as humidity, press room ventilation, type of press tools, machine springback, etc., are consistent, and the data obtained can be directly transferred to subsequent production operation.

[0019] By integrating the components for the test pressing, especially the test pressing device, into the rotary press, it may be possible to eliminate the need to convert the rotary press to switch to production mode. Switching directly from a single pressing during a test pressing to a production mode is generally possible. The values ​​determined during the test pressing can be used directly for subsequent production mode without further adjustment.

[0020] According to one embodiment, it can be provided that the pressing force and / or a parameter characterizing the pressing force is determined during the test pressing, and that when a predetermined pressing force and / or a predetermined value of the parameter characterizing the pressing force is reached, the test pressing is terminated by moving the upper and lower test pressing tools apart. This is a particularly important parameter for setting up rotary presses for production operation. Furthermore, the method according to the invention or the rotary press configured for this purpose according to the invention ensures that the desired pressing force is reliably reached and not exceeded during the first pressing process. Complex trial and error procedures can be eliminated.

[0021] According to one embodiment, the parameter characterizing the pressing force can be a web height, a pressing force curve, and / or a pressure holding time at a given pressing force. The web height can be determined, for example, via the axial travel of the upper and lower pressing rams. The pressure holding time is a hold-down phase. It describes the period during which the compact is compressed to its smallest volume. The pressing force can vary during this period. The travel of the rams no longer changes. The pressing force curve can be recorded over time.

[0022] The pressing force and / or the parameter characterizing the pressing force can be taken into account when setting the rotary press for production operation.

[0023] According to a further embodiment, during the test pressing, only the punch pair assigned to the die plate holder is installed in the rotor. The remaining punch pairs of the rotor can be removed. Of course, it would also be possible to leave some of the rotor's punch pairs in the rotor and remove some punch pairs, or to leave all punch pairs in the rotor. The presence of only the punch pair used for the test pressing has the advantage that there is no interaction between punch pairs and components of the rotary press.

[0024] According to a further embodiment, the filling device of the rotary press can be disassembled or deactivated during the test pressing. This has the advantage that the receptacles not used during the test pressing are not undesirably filled with material to be pressed. For example, it is possible to completely or partially remove the filling device from the rotor. However, it can also be emptied, or a filling opening through which material from the filling device is filled into the receptacles can be closed. Complex measures to prevent filling of receptacles, such as the insertion of dummy dies, can thus be avoided.

[0025] According to a particularly practical design, the material to be pressed during the test pressing can be filled into the receptacle manually. However, it is also conceivable to fill the material into the receptacle using the filling device or another filling device.

[0026] According to a further embodiment, it can be provided that several test pressings are carried out, wherein the pressing force curve and / or the punch travel curve are varied by varying the drive speed of the test pressing drive. For example, during the test pressing or during several test pressings, a sinusoidal and / or sawtooth-shaped and / or rectangular pressing force curve and / or punch travel curve can be set by the test drive. Due to the test pressing drive of the test pressing device, which is largely freely controllable and adjustable according to the invention, largely freely defined trajectories can be specified and traversed during one or more test pressings. The different trajectories can be pressings on different rotary presses or standardized trajectories, for example for finding suitable parameters for new products made from the material to be pressed.This makes it easier to find the optimal setting of the rotary press for later production operation.

[0027] According to a further embodiment, the upper and lower test compression tools can be moved apart by the test compression drive after a first test compression process and then brought closer together again by the test compression drive, so that the upper compression ram and the lower compression ram are pressed toward each other by the upper and lower test compression tools in the receptacle of the die plate for further compression of the material filled into the receptacle into a test compact. In this way, multiple compressions can be simulated, such as those found in compression devices with several compression tools, for example, several compression rollers, in particular pre-compression rollers and main compression rollers, which are traversed one after the other as the rotor rotates.This allows the subsequent production operation to be simulated even better during the test pressing so that the optimal setting parameters of the rotary press can be found.

[0028] The test press drive is a linear drive. In particular, two test press drives can be provided, one of which drives the upper test press tool and the other the lower test press tool. The test press drives can be individually controllable or regulated, thus enabling particularly flexible execution of the test pressing. According to a particularly practical embodiment, the test press drive can comprise an electric or hydraulic drive. Such drives can be controlled or regulated particularly precisely and flexibly and are thus particularly suitable for the invention. In contrast to a conventionally provided adjustment drive for the pressing tools, in particular the pressure rollers, of the pressing device, the test press drive actively serves to press a pressed part. The conventionally provided adjustment drive serves only to adjust the height of the pressing tools.The kinetic energy is provided by the main drive of the rotary press, which drives the rotor. The test press drive is essentially also an adjustment drive, but it itself provides the feed of the press rams for pressing the material in the holder into a compact. While a conventional adjustment drive for pressure tools, such as pressure rollers, can only be moved to a target point, the test press drive makes it possible to follow a defined trajectory. Other parameters, such as the press force, influence the trajectory. Thus, the test press drive can be used to simulate a single-ram press in the environment of a standard rotary press.

[0029] The rotary press can further comprise a control device designed to control the test press drive. The method according to the invention can, for example, be carried out under the control of the control device of the rotary press, in particular automatically, except for manual filling of the receptacle. The control device can be formed by or integrated into the machine control system for controlling the rotary press during production. Based on the results of the test pressing, the rotary press can be configured with all components for later production operation. This can also be done by the control device. This concerns, for example, the desired setting of the dosing curves and / or the pressure device, in particular the pressure tools such as pressure rollers, and / or the rotational speed of the rotor.To the extent that parameters are determined according to the invention, such as the pressing force or a parameter characterizing the pressing force, these parameters can be measured using appropriate sensors. For this purpose, the rotary press according to the invention can have appropriate sensors, for example, pressing force sensors on the pressing device, for example arranged on pressing tools, in particular pressure rollers. The parameter characterizing the pressing force curve and / or any additional parameters determined can also be measured using appropriate sensors on the rotary press.

[0030] According to a further embodiment, the upper and lower test pressing tools can be formed by the upper and lower pressure tools of the pressure device. The pressure tools, for example upper and lower pressure rollers, usually already have linear guides or eccentric guides, via which they can be adjusted to a defined distance using an adjustment device. In addition, the pressure tool holders often already have a press force sensor, which can be used to measure the press force and control the drives, for example the rotary drive of the rotor and / or the test pressing drive. As explained, conventional adjustment drives for the axial adjustment of pressure tools, such as pressure rollers, are not suitable for carrying out the test pressing according to the invention. The test pressing drive can, in particular, replace an adjustment drive for adjusting the upper and lower pressure tools.The test press drive can also include a gearbox that can replace a gearbox of the adjustment drive.

[0031] In addition to the pressure tools, other positions on the rotor are also possible for integrating the test press device with the test press drive. Accordingly, the upper and lower test press tools can be test press tools designed separately from the pressure device and not necessarily participating in the production operation of the rotary press. For example, upper and lower actuators driven by the test press drive can be arranged at a rotor position separate from the pressure device. These actuators can be pressed towards each other by the test press drive, so that the upper and lower press rams in the test press position press the material filled into the holder to form the test compact. In this case, it is not necessary to modify the pressure device of the rotary press for the inventive integration of the test press device.In regular production operation, the actuators can be used in a particularly practical manner to form upper and lower guide cam elements for guiding the press rams rotating with the rotor. This makes it particularly easy to convert existing rotary presses by removing the upper and lower control cam elements at a test press position and replacing them with the upper and lower actuators driven by the test press drive.

[0032] As already explained, the upper and lower pressure tools can be formed by upper and lower pressure rollers or pressure wedges.

[0033] The method according to the invention can be carried out using the rotary press according to the invention. Accordingly, the rotary press according to the invention can be designed to carry out the method according to the invention.

[0034] An embodiment of the invention is explained in more detail below with reference to the figures. They show schematically: Fig. 1 a rotary press according to the invention and used in the method according to the invention in a developed view of the rotor, Fig. 2 different possible pressing force curves that can be realized with the rotary press according to the invention or the method according to the invention.

[0035] Unless otherwise stated, the same reference symbols in the figures refer to the same objects.

[0036] The Fig. The rotary press shown in Figure 1 is a rotary press for tablet production, as can be used in the present invention, in which powdered material is compressed into pellets, in particular tablets. The rotor of the rotary press is driven in rotation by a rotary drive and comprises a die plate 10 having a plurality of receptacles 12. The receptacles 12 can be formed, for example, by bores in the die plate 10. The rotor further comprises a plurality of upper press punches 14 and lower press punches 16 that rotate synchronously with the die plate 10. The upper press punches 14 are axially guided in an upper punch guide 18, and the lower press punches 16 are axially guided in a lower punch guide 20. The axial movement of the upper press punches 14 and lower press punches 16 during the rotation of the rotor is controlled by upper control cam elements 22 and lower control cam elements 24.Furthermore, a filling device 26 is provided, which has a filling reservoir 28 and a filling chamber 30, which are connected via a filling tube 32. In this way, in the present example, powdered material flows by gravity from the filling reservoir 28 via the filling tube 32 into the filling chamber 30 and from there, by gravity, into the receptacles 12 of the die plate 10 via a filling opening provided on the underside of the filling chamber 30.

[0037] The rotary press further comprises a printing device 34. In the example shown, the printing device 34 comprises a pre-pressing device with an upper pressure roller 36 held on an upper holder and a lower pressure roller 38 held on a lower holder, as well as a main printing device with an upper pressure roller 40 held on an upper holder and a lower pressure roller 42 held on a lower holder. In addition, the rotary press comprises an ejection device 44 and a stripping device 46 with a stripping element which feeds the tablets 48 produced in the rotary press to a discharge device 50 for removal from the rotary press.The stripping device 46 can, for example, comprise a preferably sickle-shaped stripping element which, in the region of the ejection device 44, strips tablets 48 conveyed by the lower press punches 16 onto the upper side of the die plate 10 from the die plate 10 and feeds them to the discharge device 50.

[0038] Furthermore, the rotary press comprises a control device 52 for controlling the operation of the rotary press and for carrying out the method according to the invention, as explained in more detail below.

[0039] The rotary press according to the invention further comprises a test press device for test pressing of compacts in the rotary press. For illustration, Fig. Figure 1 shows three possible designs of test presses. These can be incorporated in the rotary press in whole or in part. However, it is also possible that only one of the test presses shown is used.

[0040] In the example shown, the upper pressure roller 36 and the lower pressure roller 38 of the pre-pressure device form a first upper test press tool 36 and a lower test press tool 38, respectively. The upper pressure roller 40 and the lower pressure roller 42 of the main pressure device 34 form a second upper test press tool 40 and a lower test press tool 42, respectively. Fig. 1 in the area of ​​the ejection position of the rotor, a third upper test pressing tool 54 and a third lower test pressing tool 56 are provided, which are designed as actuators that can replace corresponding control cam elements in the area of ​​the ejection position.

[0041] In the example shown, each of the upper and lower test press tools 36, 38, 40, 42, 54, 56 is assigned a test press drive 58. The test press drives 58 each act on the test press tool 36, 38, 40, 42, 54, 56 assigned to them via a connection 60. The connections 60 can form or comprise a gear mechanism of the respective test press drive 58. For example, the connections 60 can each comprise a toothed belt, toothed belt pulleys, a planetary screw drive with a nut, and a drive shaft. The test press drives 58 can be, for example, hydraulic or electric drives.

[0042] For a test pressing with the first test pressing device, a punch pair consisting of an upper and a lower press punch 14, 16 assigned to a holder 12 of the die table 10 is brought into a test pressing position, which in this case is arranged in the region of the smallest distance between the upper pressure roller 36 and the lower pressure roller 38 as the first upper test pressing tool 36 and the first lower test pressing tool 38. The upper pressure roller 36 as the upper test pressing tool 36 and the lower pressure roller 38 as the lower test pressing tool 38 are initially moved apart by means of the test pressing drives 58 so that the punch pair can be easily brought into the test pressing position, for example by rotating the rotor. Before, during, or after moving into the test pressing position, the holder 12 assigned to the punch pair is filled with the material to be pressed, for example manually.Subsequently, the upper and lower pressure rollers 36, 38, as the first upper and lower test pressing tools 36, 38, are moved towards one another by means of the respectively assigned test pressing drives 58, so that the upper press ram 14 and the lower press ram 16 of the ram pair are pressed towards one another by the upper and lower test pressing tools 36, 38 in the holder 12 of the die plate 10 to press the material filled into the holder into a test compact. After the test pressing is completed, the first upper and lower test pressing tools 36, 38 can be moved apart, again controlled by the test pressing drives 58, so that the test compact can be removed from the holder 12. For this purpose, the rotor can be moved into an ejection position, in which the lower press ram 16 ejects the produced test compacts onto the upper side of the die plate 10.The test press drives 58, like the rotor, can be controlled by the control device 52. As explained in more detail below, for example, a previously defined press force can be realized during the test pressing. Different press force curves or punch travel curves can also be realized. On this basis, the rotary press can be optimally adjusted for later production operation. In the present example, the test press drives 58 act on the pressure rollers 36, 40 or 38, 42 as test pressing tools. They can replace an adjustment drive for the pressure rollers 36, 40 or 38, 42 for adjusting the axial distance between the pressure rollers 36, 40 or 38, 42, if necessary including a gear for the adjustment drive.

[0043] In the same way as for the first test pressing device with the pressure rollers 36 and 38 as first test pressing tools, a test pressing can be carried out by means of the Fig. 1. The test pressing positions into which the punch pair is brought, for example, by corresponding rotation of the rotor, differ. In particular, the punch pair for carrying out a test pressing with the second test pressing device, comprising the pressure rollers 40 and 42 as second upper and lower test pressing tools 40, 42, is located at a rotational position of the rotor that corresponds to the smallest distance between the upper and lower pressure rollers 40, 42. Once this position is reached, a test pressing can also be carried out with the second test pressing device in the manner explained above for the first test pressing device.

[0044] Accordingly, a test pressing can be carried out with the third test pressing device, in which case the test pressing position corresponds to the position of the Fig. 1 corresponds to the pair of punches shown on the far right. Once this position has been assumed, a test pressing can be carried out again, if necessary after moving the third test pressing tools 54, 56 apart by means of the test pressing drives 58 and filling the receptacle 12 with the material to be pressed, by pressing the third test pressing tools 54, 56 towards each other by means of the associated test pressing drives 58. It is understood that for this purpose, the lower pressing punch 16 is moved further downward so that the receptacle 12 can be filled to the desired fill level.

[0045] As explained, the rotary press according to the invention can be used to conduct test pressings with different pressing force profiles. It is also possible for the rotary press to be equipped with press force sensors in the area of ​​the test pressing devices described above, which measure the pressing force during the test pressing. This ensures that a desired pressing force is reliably reached and not exceeded.

[0046] Fig. 2 shows different possible pressing force curves, for example over time. Fig. 2, from left to right, shows a sinusoidal pressing force curve, a sawtooth-shaped pressing force curve, a multiple pressing force curve, and a rectangular pressing force curve. The multiple pressing force curve can, for example, simulate pressing in a rotary press with pre-pressure and main pressure devices, which the press rams pass through successively during rotation. The different heights of the respective pressing force curves in the third illustration from the left in Fig. 2 simulates the lower pressing force in the area of ​​the pre-pressure device compared to the main pressure device. List of reference symbols 10 die plate 12 recordings 14 upper press ram 16 lower press ram 18 upper punch guide 20 lower punch guide 22 upper control cam element 24 lower control cam element 26 Filling device 28 Filling reservoir 30 filling chamber 32 filling tube 34 Main printing device 36, 40, 54 upper pressure roller / test press tool 38, 42, 56 lower pressure roller / test press tool 44 Ejection device 46 Stripping device 48 pellets 50 Drainage device 52 Control device 58 Test press drive 60 connection

Claims

[1] A method for the test pressing of compacts (48) in a rotary press, comprising a rotationally driven rotor with upper and lower press punches (14, 16), an upper and lower punch guide (18, 20) for the upper and lower press punches (14, 16) and a die plate (10) between the punch guides (18, 20), wherein the upper and lower press punches (14, 16) interact with receptacles (12) of the die plate (10) during production operation of the rotary press, further comprising a filling device (26) in which material to be pressed is filled into the receptacles (12) during production operation of the rotary press, further comprising a pressure device (34) with upper and lower pressure tools which interact with the upper and lower press punches (14, 16) during production operation of the rotary press, so that they press material located in the receptacles (12) into compacts, characterized bythat the procedure includes the following steps: • material to be pressed is filled into a receptacle (12), • a pair of punches comprising an upper and lower press punch (14, 16) assigned to the holder (12) of the die plate (10) is brought into a test pressing position in which the upper press punch (14) is located in an area of ​​action of an upper test pressing tool (36, 40, 54) of a test pressing device of the rotary press and the lower press punch (14) is located in an area of ​​action of a lower test pressing tool (38, 42, 56) of the test pressing device, • the upper and lower test pressing tools (36, 40, 54, 38, 42, 56) are moved towards one another by means of a test pressing drive (58) of the test pressing device, so that the upper pressing punch (14) and the lower pressing punch (16) are pressed towards one another by the upper and lower test pressing tools (36, 40, 54, 38, 42, 56) in the receptacle (12) of the die plate (10) in order to press the material filled into the receptacle (12) into a test compact (48). [2] Method according to claim 1, characterized by that during the test pressing the pressing force and / or a parameter characterizing the pressing force are determined, and that when a predetermined pressing force and / or a predetermined value of the parameter characterizing the pressing force is reached, the test pressing is terminated by moving the upper and lower test pressing tools (36, 40, 54, 38, 42, 56) apart. [3] Method according to claim 2, characterized bythat the parameter characterizing the pressing force is a web height, a pressing force curve and / or a pressure holding time at a given pressing force. [4] Method according to one of claims 2 or 3, characterized by that the pressing force and / or the parameter characterizing the pressing force is taken into account for setting the rotary press for production operation. [5] Method according to one of the preceding claims, characterized by that during the test pressing only the punch pair assigned to the holder (12) of the die plate (10) is installed in the rotor. [6] Method according to one of the preceding claims, characterized by that the material to be pressed during the test pressing is manually filled into the holder (12). [7] Method according to one of the preceding claims, characterized bythat several test pressings are carried out, whereby the pressing force curve and / or the punch travel curve are varied by varying the drive speed of the test press drive. [8] Method according to one of the preceding claims, characterized by that during the test pressing or several test pressings a sinusoidal and / or sawtooth-shaped and / or rectangular pressing force curve and / or punch travel curve is set by adjusting the drive speed of the test press drive. [9] Method according to one of the preceding claims, characterized bythat the upper and lower test pressing tools are moved apart after a first test pressing process by means of the test pressing drive and are then brought towards one another again by means of the test pressing drive, so that the upper press punch (14) and the lower press punch (16) are pressed towards one another by the upper and lower test pressing tools in the holder (12) of the die plate (10) for further pressing of the material filled into the holder (12) to form a test compact. [10] Method according to one of the preceding claims, characterized by that it is carried out with a rotary press according to one of the following claims. [11] Rotary press, comprising a rotationally driven rotor with upper and lower press punches (14, 16), an upper and lower punch guide (18, 20) for the upper and lower press punches (14, 16) and a die plate (10) between the punch guides (18, 20), wherein the upper and lower press punches (14, 16) cooperate with receptacles (12) of the die plate (10) during production operation of the rotary press, further comprising a filling device (26) in which material to be pressed is filled into the receptacles (12) during production operation of the rotary press, further comprising a pressure device (34) with upper and lower pressure tools which cooperate with the upper and lower press punches (14, 16) during production operation of the rotary press, so that they press material located in the receptacles (12) into compacts (48), characterized bythat the rotary press further comprises a test pressing device, comprising an upper test pressing tool (36, 40, 54) and a lower test pressing tool (38, 42, 56), wherein for a test pressing the upper test pressing tool (36, 40, 54) cooperates with an upper press punch (14) assigned to a receptacle (12) of the die plate (10) and the lower test pressing tool (38, 42, 56) cooperates with a lower press punch (16) assigned to the same receptacle (12), and comprising a test pressing drive which moves the upper test pressing tool (36, 40, 54) and the lower test pressing tool (38, 42, 56) towards one another for a test pressing, so that the upper press punch (14) and the lower press punch (16) are moved by the upper and lower test pressing tools (36, 38, 40, 42, 54,56) in the receptacle (12) of the die plate (10) are pressed towards each other to press material filled into the receptacle (12) into a test compact (48)., [12] Rotary press according to claim 11, characterized by that the test press drive includes an electric or hydraulic drive. [13] Rotary press according to one of claims 11 or 12, characterized by that the rotary press comprises a control device (52) which is designed to control the test press drive. [14] Rotary press according to one of claims 11 to 13, characterized by that the upper and lower test pressing tools (36, 40, 54, 38, 42, 56) are formed by the upper and lower pressure tools of the pressure device. [15] Rotary press according to one of claims 11 to 13, characterized bythat the upper and lower test pressing tools (36, 40, 54, 38, 42, 56) are test pressing tools designed separately from the pressure device (34). [16] Rotary press according to one of claims 11 to 15, characterized by that the upper and lower pressure tools (36, 40, 54, 38, 42, 56) are formed by upper and lower pressure rollers (36, 40, 54, 38, 42, 56). [17] Rotary press according to one of claims 11 to 16, characterized by that it is designed to carry out the method according to one of claims 1 to 10.

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