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

Abstract

To provide a method for test pressing pellets in a rotary press.SOLUTION: A method for test pressing pellets in a rotary press includes a step in which a material to be pressed is filled in a receptacle; a step in which an upper press punch in a punch pair of the upper and lower press punches allocated to the receptacle of a die plate is located in an impact area of an upper test pressing tool of a test pressing apparatus of a rotary press, the lower press punch is guided to a test press position located in the impact area of a lower test pressing tool of the test pressing apparatus; and a step in which the upper and the lower test pressing tools are advanced towards each other via a test pressing drive of the test pressing apparatus so that the upper press punch and the lower press punch are driven towards each other in the receptacle of the die plate by the upper and lower test pressing tools to press the material filled in the receptacle into a test pellet.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method of test pressing pellets in a rotary press, the rotary press comprising a rotary driven rotor with upper and lower press punches, upper and lower punch guides for the upper and lower press punches, and a die plate between the punch guides, the upper and lower press punches interacting with receptacles in the die plate in a production mode of the rotary press, further comprising a filling device whereby the receptacles are filled with material to be pressed in the production mode of the rotary press, and further comprising a press apparatus with upper and lower press tools interacting with the upper and lower press punches to press the material in the receptacles into pellets in the production mode of the rotary press. The present invention also relates to a rotary press comprising a rotary driven rotor with upper and lower press punches, upper and lower punch guides for the upper and lower press punches, and a die plate between the punch guides, the upper and lower press punches interacting with receptacles in the die plate in a production mode of the rotary press, further comprising a filling device in which the receptacles are filled with material to be pressed in the production mode of the rotary press, and further comprising a pressing device with upper and lower press tools interacting with the upper and lower press punches to press the material in the receptacles into pellets in the production mode of the rotary press.

[0002] Test pressings are performed, for example, for new materials to be pressed, in order to determine the optimal setting parameters of a rotary press for producing pellets in production mode. The pellets may in particular be tablets. In the context of test pressings, a separate press, which produces, for example, only one pellet, is desirable for pressing tablets with minimal product use. The use of rotary presses is known for mass-producing pellets. To bring about the necessary pressing force for producing pellets, the press punch moves against the guide geometry of the pressing device, which consists, for example, of upper and lower compression rollers or compression wedges. The pressing speed and pressure holding time are determined by the rotation speed of the rotor, the guide geometry and the shape of the punch head of the press punch. In principle, the guide geometry can be influenced by various means. For example, the guide curves of the press punch can be adapted. These control the axial movement of the press punch over the orbit that rotates with the rotor. Furthermore, in rotary presses, it is possible to influence the pressing force by slightly axially adjusting the press tools, such as, for example, the compression rollers or compression wedges. The closer the opposing upper and lower press tools are brought together, the more the pellets are compressed during the pressing process and the smaller the web height. This results in a higher pressing force. Naturally, the subsequent pressing of the pellets is influenced by varying the spacing between the upper and lower press tools. For example, in a rotary press, the height of the web of pellets is a settable dimension. The hardness of the pellets and the force required to move them through the rotary press, in particular the geometry of the guides of the pressing device, can be determined therefrom. It is also possible to adjust the pressing force by adjusting the web height during operation via the measured pressing force.

[0003] Furthermore, linear presses or single punch presses are known for test pressing and are usually used to produce small quantities of tablets. One field of application is the research and development of new drugs and new product compositions. To compress the pellets, the opposing press tools are moved towards each other. This can be done by axially moving both press tools or by axially moving only one press tool. This movement is carried out via a linear drive, for example a spindle drive. In this type of single press, both the height of the pellet web and the pressing force can be set as target values. From this result, different values ​​arise.

[0004] When carrying out a test pressing with a defined pressing force curve in a rotary press provided for the normal production mode, first the spacing of the press tools must be determined, resulting in the desired pressing force in each case. This is only possible in a rotary press by a trial-and-error method of first setting the pellet height, evaluating the resulting pressing force and adapting the pellet height, and these steps must be repeated until the desired pressing force is reached. For this reason, a considerable amount of material has to be pressed. The guide geometry, in particular the spacing of the opposing press tools, is adapted very slowly in a rotary press and is controllable only within a very limited range. This spacing can also be set using the aforementioned adjustment of the pressing force. The setting of the spacing of the punches resulting from the pressing force is also very time-consuming in many control steps. Apart from this, the predefined spacing position of the press tools is approached at a constant speed by the adjusting drive and cannot be adjusted freely. The adjustment of the opposing press tools only adapts the pressing force within a narrow range and is carried out during the continuous operation of the rotary press. This means that the average value of one or more pellets is recorded. This value then becomes the basis for readjusting the press tool spacing, during which more pellets are produced that are not produced to the desired condition, resulting in waste.

[0005] In contrast, linear presses are not suitable for the production of large quantities of pellets. Moreover, the necessity of providing a separate test press in addition to the rotary press provided for the production mode is also disadvantageous in terms of effort. Moreover, the data generated thereby cannot be directly transferred to the rotary press provided for the production mode, in particular due to the different components of the press and other parameters such as ventilation of the press room or machine suspension. The generated data must therefore be adapted to the production press. To do so, it is routinely necessary to carry out an additional test press on the rotary press provided for the production mode, which further increases the effort.

[0006] German patent no. 10319024B3 discloses a method for test pressing of tablets on a rotary tablet press, which is carried out on a rotary press installed in the normal production mode. The punch pairs selected for the individual presses are automatically moved to the filling position and one or a limited number of dies are filled with material by a stationary rotor in an at least partially separated filling arrangement. The rotor is then set in rotation and accelerated in the pressing station of the rotary press to have the desired production speed. After one revolution, the rotor stops again in the filling position. During the rotation of the rotor, signals or signal curves from the measuring points are recorded and sent to a computer for display and evaluation. The advantage of this method is that no separate test press is required for the test press. This reduces the effort. At the same time, the data obtained in the context of the test press can be used substantially as is without adaptation, since it has already been generated on a rotary press installed in the production mode. This also reduces the effort. Since one or several dies are filled with material, the product input required for the test press can also be reduced to a minimum. However, initially unknown pressing forces occur at the pressing station because the web height of the tablets to be produced must be estimated during the first test press based on the fill in the die. The desired pressing force for a particular product must then be determined accordingly in a series of test presses. This further increases the labor and product input.

[0007] Based on the above-mentioned prior art, the object of the present invention is to provide a method and a rotary press of the type mentioned at the beginning, with which a test pressing for setting the rotary press in production mode can be carried out reliably and with little effort.

[0008] The invention achieves this object by means of the independent claims 1 and 11. Advantageous embodiments can be found in the dependent claims, the description and the drawings.

[0009] For a method of the type mentioned at the beginning, the invention achieves this object by the following steps: - filling a receptacle with a material to be pressed; - directing a punch pair consisting of an upper and a lower press punch assigned to the die plate receptacle to a test press position in which the upper press punch is located in a collision area of ​​an upper test press tool of a test press device of the rotary press and the lower press punch is located in a collision area of ​​a lower test press tool of the test press device; moving the upper test press tool and the lower test press tool relative to each other using a test press drive of the test press apparatus such that the upper press punch and the lower press punch are pressed against each other in the receptacle of the die plate by the upper and lower test press tools to press the material filled in the receptacle into test pellets.

[0010] For a rotary press of the type mentioned at the beginning, the invention achieves this object in that the rotary press further comprises a test press device, which comprises an upper test press tool and a lower test press tool, and for test pressing, the upper test press tool interacts with an upper press punch assigned to a receptacle in the die plate and the lower test press tool interacts with a lower press punch assigned to the same receptacle, and the test press device comprises a test press drive which moves the upper and lower test press tools relative to one another for test pressing, such that the upper press punch and the lower press punch are pressed against one another in the receptacle of the die plate by the upper test press tool and the lower test press tool in order to press the material filled in the receptacle into test pellets.

[0011] The rotary press according to the invention or the rotary press used in the method according to the invention is a rotary press provided for the usual production mode of pellets, in particular tablets, made of powder material. In a manner known per se, the rotary press comprises a rotor with a number of upper and lower press punches, which are respectively assigned in pairs to receptacles or cavities of the die plate. The receptacles may be designed as holes present directly in the die plate. However, they may also be designed as sleeve-like inserts that are inserted into correspondingly sized receptacles of the die plate. During operation of the rotary press, the upper and lower press punches rotate together with the die plate, whereby the axial movement of said press punches is controlled by a control cam and guided by an upper and lower punch guide. The control cam generally interacts with the punch head of the press punch. During rotation, the die plate passes through various devices of the rotary press in production mode, namely the filling device and the pressing device, in which the powder material to be pressed is filled into the receptacles of the die plate, and in which the upper and lower press punches are pressed into the receptacles by upper and lower press tools, for example upper and lower compression rollers, in order to press the powder material into pellets, for example tablets. The pressing device may have upper and lower pre-press tools, in particular pre-compression rollers, as well as upper and lower main press tools, in particular main compression rollers. As an alternative to the compression rollers, it is also possible to use compression wedges. Downstream of the pressing device, in production mode, the upper press punch is guided upwards from the receptacle and the pellets produced in the receptacle are pressed by the lower press punch against the upper surface of the die plate. To this end, a discharge cam is provided, which moves the lower press punch upwards. The pellets are then scraped, for example by a scraper, from the die plate to the outlet of a rotary press from which they are fed for further processing. The control cam also generally includes a metering cam which, when the upper press punch is guided upwardly from a particular receptacle, brings the lower press punch into a predetermined position partially inserted into the receptacle.In this metering position, the lower press punch forms the bottom surface of a particular receptacle and thus defines the fill height of the material to be filled into the receptacle.

[0012] As already explained, the rotary press used according to the invention is a rotary press provided for normal production mode, which can be adapted to carry out the method according to the invention, as explained in detail below. In particular, components of the rotary press, such as the upper and lower press punches and / or the filling device, can be removed before the start of the test pressing.

[0013] According to the invention, the rotary press has a test press device with an upper test press tool and a lower test press tool. In the method according to the invention, a punch pair consisting of an upper press punch and an opposing lower press punch, which are assigned to a receptacle of the die plate, is introduced into a test press position, in which the upper press punch is located in the collision area of ​​the upper test press tool and the lower press punch is located in the collision area of ​​the lower test press tool. The punch pair can be introduced into the test press position by driving the rotor in rotation to a position in which the punch pair is located in the collision area of ​​the test press tool. Before, simultaneously with or after the introduction of the punch pair into the test press position, the receptacle to which the punch pair is assigned is filled with the material to be pressed. The receptacle can be filled, for example, manually. The receptacle can be filled to its maximum extent. Excess material can be scraped off from the upper surface of the die plate. It is also possible to fill the receptacle only partially, so that the previously metered amount is reliably and completely received in the receptacle and can then be pressed. The upper and lower test press tools are then moved towards each other by the test press drive of the test press device so that the upper and lower test press tools first come into contact with the upper press punch and the lower press punch, respectively, and the upper and lower press punches are pressed against each other so that the punch pairs press the material in the receptacle into test pellets. The upper and lower test press tools can not only move the upper press punch axially towards the lower press punch, but also move the lower press punch axially towards the upper press punch. However, it is also possible, for example, to move only one of the press punches axially and press against the other press punch axially fixed by a particular test press tool. In this case, the press punch places its punch tip in the receptacle, as in the pressing of normal pellets, and presses the material between its punch tips to form pellets, for example tablets.

[0014] After the test pressing is completed, the upper and lower test press tools can be separated using the test press drive and the produced test pellets can be removed, for example by rotating the rotor to a discharge position where the upper press punch is moved upward from the receptacle and the produced test pellets are pressed by the lower press punch against the upper surface of the die plate.

[0015] In the rotary press according to the invention, therefore, a test press device is provided which reproduces the properties of a linear press for pressing pellets individually in the environment of the rotary press provided for the normal production mode. The test press device with the test press drive makes it possible to individually control the test press tools and thus dynamically drive them towards each other to press the material into test pellets. The normal pressing process in the rotary press can be reliably and precisely, possibly automatically, reproduced according to preselected parameters or respective path curves by individually controlling the test press drives. The test press drives can also be adjusted during the test pressing, so that the advantageous properties of the linear press described at the beginning can be fulfilled without incurring its disadvantages. As already mentioned, the rotary drive of the rotor can be utilized to guide the punch pair into the test pressing position. The rotary drive can also be used, for example, to fix the press punch during the test pressing so that the press punch cannot move radially during the pressing process.

[0016] By integrating the test press equipment for single individual presses according to the invention into the rotary press provided for the production mode, the acquisition costs of a separate linear press and the training costs of personnel can be avoided. Installation space, which is usually insufficient in laboratories where such presses are often used, is saved. The test press environment in the rotary press is the same as in the subsequent production mode. This means that the influences of humidity, ventilation of the press room, type of press tools, machine suspension, etc. are the same and the data obtained can be transferred as is to the subsequent production mode. Since the components for the test press, in particular the test press equipment, are integrated into the rotary press, it would not be necessary to modify the rotary press in order to switch to the production mode. In principle, it is possible to switch directly from the individual presses in the test press to the production mode. The values ​​determined in the test press can be used as is in the subsequent production mode without further adaptation.

[0017] According to one embodiment, the pressing force and / or a parameter characterizing the pressing force is determined during the test pressing, and the test pressing may be terminated by separating the upper and lower test press tools when a predefined value of the predefined pressing force and / or a parameter characterizing the pressing force is reached. This is a crucial parameter for setting the rotary press in production mode. Furthermore, the method according to the invention or, respectively, the rotary press configured for this purpose according to the invention ensures that the pressing force desired in each case is reliably reached and not exceeded in the first pressing step. Complicated trial and error steps can be dispensed with.

[0018] According to one embodiment, the parameters characterizing the pressing force may be the web height, the pressing force curve and / or the pressure holding time at a defined pressing force. The web height may be determined, for example, via the axial path of the upper and lower press punches. The pressure holding time is the running holding phase. It represents the period until the pellets are compressed to a minimum volume. During this period, the pressing force may vary. The path of the punches no longer changes. The pressing force curve can be recorded over time.

[0019] The pressing force and / or parameters characterizing the pressing force may be taken into account for configuring the rotary press for the production mode.

[0020] According to another embodiment, it is possible to install only the punch pairs that are assigned to the receptacles of the die plate on the rotor during the test press. The other punch pairs of the rotor are removable. It is of course also possible to leave some of the punch pairs of the rotor on the rotor, to remove some punch pairs or to leave all punch pairs on the rotor. Since only the punch pairs that are used for the test press are present, there is the advantage that there is no further interaction between the punch pairs and the components of the rotary press.

[0021] According to another embodiment, the filling device of the rotary press can be removed or deactivated during the test pressing. This has the advantage that receptacles not used during the test pressing are not filled undesirably with the material to be pressed. For example, the filling device can be completely or partially removed from the rotor. However, it can also be emptied and the filling port through which the material is filled from the filling device into the receptacle can be closed. It is thus possible to avoid elaborate measures to prevent the filling of the receptacle, for example the insertion of a dummy die.

[0022] According to a particularly practical embodiment, the material to be pressed during the test press may be filled into the receptacle manually, but it is also conceivable to fill the receptacle with the material using this or a separate filling device.

[0023] According to another embodiment, several test presses may be carried out, varying the pressing force curve and / or punch path curve by varying the drive speed of the test press drive. For example, sinusoidal and / or sawtooth and / or rectangular pressing force curves and / or punch path curves can be set by the test press drive in the context of a test press or in the context of several test presses. Due to the highly freely controllable or individually adjustable test press drive of the test press device according to the invention, highly freely defined path curves can be specified and executed in the context of one or several test presses. For example, different path curves can be pressings on different rotary presses or standardized path curves in order to find suitable parameters for a new product made of the material to be pressed. This makes it easier to find the optimal rotary press settings for the subsequent production mode.

[0024] According to another embodiment, the upper and lower test press tools may be moved away from each other after the first test pressing step using the test press drive and then moved towards each other again using the test press drive, so that the upper and lower test press tools press against each other in the receptacles of the die plate to further press the material filled in the receptacles into test pellets. In this way, it is possible to simulate multiple pressings, as for example with a pressing device with multiple pressing tools, such as multiple compression rollers, in particular pre-compression rollers and main compression rollers, which pass over time during the rotation of the rotor. This makes it possible to better simulate later production modes in the context of the test press, so that the optimal setting parameters of the rotary press can be found.

[0025] The test press drive is a linear drive. In particular, it is possible to provide two test press drives, one of which drives the upper test press tool and the other of which drives the lower test press tool. In order that the test pressing can be carried out particularly flexibly, the test press drives are individually controllable or respectively adjustable. According to a particularly practical embodiment, the test press drive may comprise an electric drive or a hydraulic drive. Such drives are particularly precisely and flexibly controllable or respectively adjustable and are therefore particularly suitable for the invention. In contrast to the adjusting drives that are usually provided for the press tools of the pressing device, in particular for the compression rollers, the test press drive functions actively to press the pellets. The adjusting drives that are usually provided are merely for setting the height of the press tool. The kinetic energy is provided by the main drive of the rotary press, which drives the rotor. The test press drive is also in principle an adjusting drive, but it itself feeds the press punch in order to press the material in the receptacle into pellets. Conventional adjusting drives for press tools, such as compression rollers, can only be moved up to a target point, whereas with the test press drive it is possible to travel a defined path curve. Other parameters such as the pressing force also affect the path curve. Therefore, with the test press drive it is possible to simulate a single punch press in the environment of a conventional rotary press.

[0026] The rotary press may also be equipped with a control device designed to control the test press drive. The method according to the invention can be controlled, in particular automatically, by the control device of the rotary press, except for the case of manual filling of the receptacles, for example. The control device may be configured by the machine control system for controlling the rotary press in the production mode or may be respectively integrated in the machine control system. Based on the results of the test press, the rotary press may be configured with all components for the subsequent production mode. This is also possible by the control device. This concerns, for example, the desired setting of the metering cam and / or the press device, in particular the press tool such as the compression roller, and / or the rotation speed of the rotor. Insofar as parameters, such as for example the pressing force or parameters characterizing the pressing force, are determined according to the invention, these parameters can be measured by means of corresponding sensors. For this purpose, the rotary press according to the invention may have corresponding sensors, such as for example pressing force sensors on the press device, which are arranged in particular on the press tool such as the compression roller. It is also possible that the parameters characterizing the pressing force curve and / or other determined parameters can be measured by means of corresponding sensors of the rotary press.

[0027] According to another embodiment, the upper and lower test press tools may be constituted by the upper and lower press tools of the pressing device. The press tools, for example the upper and lower compression rollers, generally already have linear or eccentric guides, via which the press tools can be set to a defined distance by means of an adjustment device. Furthermore, the receptacles of the press tools often already have a pressing force sensor, which measures the pressing force and serves to adjust the drives, for example the rotary drive of the rotor and / or the test press drive. As explained, the normally provided adjusting drives for the axial adjustment of the press tools, such as the compression rollers, are not suitable for the implementation of the test press according to the invention. In particular, the test press drive may be replaced by an adjusting drive for adjusting the upper and lower press tools. The test press drive may also be equipped with a gearbox, which is replaceable with the gearbox of the adjusting drive.

[0028] However, in order to integrate the test press device with the test press drive, other positions on the rotor are also possible in addition to the press tool. The upper and lower test press tools can therefore be test press tools designed separately from the press device and do not necessarily have to be involved in the production mode of the rotary press. For example, the upper and lower actuators driven by the test press drive can be arranged at rotor positions separate from the press device and can be pressed towards each other accordingly by the test press drive so that the upper and lower press punches arranged at the test press positions can press the material filled in the receptacle into test pellets. In this case, the press device of the rotary press does not have to be modified in order to integrate the test press device according to the invention. In the normal production mode, it is possible for the actuators to form the upper and lower guide curve elements in a particularly practical way to guide the press punches rotating with the rotor. For this reason, the modification of existing rotary presses is extremely simple, since the upper and lower control cam elements at the test press positions can be removed and replaced by upper and lower actuators driven by the test press drive.

[0029] The upper and lower press tools may be comprised of upper and lower compression rollers or compression wedges as previously described.

[0030] The method according to the invention can be carried out by means of a rotary press according to the invention, which can therefore be designed to carry out the method according to the invention.

[0031] An exemplary embodiment of the invention is explained in more detail below with the aid of a schematic representation of the figures. [Brief description of the drawings]

[0032] [Figure 1] FIG. 2 shows a rotary press according to the invention, with an exploded view of a rotor used in the method according to the invention. [Diagram 2]3 shows various possible pressing force curves which can be realized with the rotary press according to the invention or with the method according to the invention, respectively;

[0033] Unless otherwise specified, like reference numbers refer to like objects in the figures.

[0034] The rotary press shown in FIG. 1 is a rotary press for tablet production that can be used in the present invention, in which powder material is pressed 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 with a number of receptacles 12. The receptacles 12 may for example be constituted by holes in the die plate 10. Furthermore, the rotor comprises a number of upper and lower press punches 14 and 16 which move in a circular motion synchronously with the die plate 10. The upper press punch 14 is guided axially in an upper punch guide 18, and the lower press punch 16 is guided axially in a lower punch guide 20. The axial movements of the upper and lower press punches 14 and 16 during the rotation of the rotor are controlled by an upper control cam element 22 and a lower control cam element 24. Furthermore, a filling device 26 is provided, which comprises a filling reservoir 28 and a filling chamber 30, which are connected via a filling tube 32. Thus, in this embodiment, the powder material passes under gravity from the fill reservoir 28 through the fill tube 32 to the fill chamber 30, and then from there through a fill opening provided in the underside of the fill chamber 30 to the receptacle 12 of the die plate 10 under gravity.

[0035] The rotary press further comprises a pressing device 34. In the example shown, the pressing device 34 comprises a pre-pressing device with an upper compression roller 36 held in an upper holder and a lower compression roller 38 held in a lower holder, as well as a main pressing device with an upper compression roller 40 held in an upper holder and a lower compression roller 42 held in a lower holder. The rotary press further comprises a discharge device 44 and a scraping device 46, the scraping device 46 having a scraping element which feeds the tablets 48 produced in the rotary press to a discharge device 50 for the discharge from the rotary press. The scraping device 46 may, for example, comprise a preferably sickle-shaped scraping element which, in the region of the discharge device 44, scrapes the tablets 48 conveyed by the lower press punch 16 to the upper surface of the die plate 10 from the die plate 10 and feeds them to the discharge device 50.

[0036] As will be described in more detail below, the rotary press further includes a controller 52 for controlling operation of the rotary press and for carrying out the method according to the present invention.

[0037] The rotary press according to the invention also comprises a test pressing device for test pressing the pellets in the rotary press. For illustrative purposes, three possible configurations of the test pressing device are shown in Fig. 1. All or a combination of the test pressing devices may be provided in the rotary press. However, it is also possible to provide only one of the test pressing devices shown.

[0038] In the illustrated example, a first upper test press tool 36 and a first lower test press tool 38 are respectively constituted by the upper compression roller 36 and the lower compression roller 38 of the pre-pressing device. An upper compression roller 40 and a lower compression roller 42 of the main pressing device 34 respectively constitute a second upper test press tool 40 and a second lower test press tool 42. Furthermore, in FIG. 1, a third upper test press tool 54 and a third lower test press tool 56 are provided in the area of ​​the discharge position of the rotor, which are designed as actuators that can be replaced by corresponding control cam elements in the area of ​​the discharge position.

[0039] In the illustrated example, a test press drive 58 is assigned to each of the upper and lower test press tools 36, 38, 40, 42, 54, 56. Each of the test press drives 58 acts on its assigned test press tool 36, 38, 40, 42, 54, 56 via a connection 60. The connection 60 may form or comprise a gearbox for the particular test press drive 58. For example, each of the connections 60 may comprise a toothed belt, a toothed belt pulley, a planetary screw drive with a nut, and a drive shaft. The test press drive 58 may be, for example, a hydraulic drive or an electric drive.

[0040] In the test pressing with the first test pressing device, the punch pair consisting of the upper and lower press punches 14, 16 assigned to the receptacle 12 of the die plate 10 is brought to a test pressing position, which in the present embodiment is located in the area where the distance between the upper compression roller 36 and the lower compression roller 38, which are respectively the first upper test press tool 36 and the first lower test press tool 38, is the smallest. For this purpose, the upper compression roller 36 as the upper test press tool 36 and the lower compression roller 38 as the lower test press tool 38 are first moved away from each other by means of the test press drive 58, so that the punch pair can be easily brought to the test pressing position, for example by rotating the rotor. Before, during or after the movement to the test pressing position, the receptacle 12 assigned to the punch pair is filled, for example manually, with the material to be pressed. The upper and lower compression rollers 36, 38 of the first upper and lower test press tools 36, 38 are then moved towards each other by means of the respective assigned test press drives 58 so that the upper press punch 14 and the lower press punch 16 of the punch pair are pressed against each other by the upper and lower test press tools 36, 38 in the receptacle 12 of the die plate 10 to press the material filled in the receptacle into test pellets. The first upper and lower test press tools 36, 38 can be moved away from each other in a controlled manner by the test press drives 58 in order to be able to remove the test pellets from the receptacle 12 after the test pressing is completed. For this purpose, the rotor can be moved to a discharge position where the lower press punch 16 discharges the produced test pellets onto the upper surface of the die plate 10. The test press drive 58 can be controlled by the control device 52, as can the control of the rotor. As will be explained in more detail below, for example, a predefined pressing force can be realized in the context of a test press. Different pressing force curves and punch travel curves are also possible, on the basis of which the rotary press can be optimally set for the subsequent production mode.In this embodiment, the test press drive 58 acts as a test press tool on the compression rollers 36, 40 or the compression rollers 38, 42, respectively. The test press drive 58 can be replaced with an adjusting drive for the compression rollers 36, 40 or 38, 42, respectively, to set the axial spacing between the compression rollers 36, 40 or 38, 42, respectively, including a gearbox for the adjusting drive if necessary.

[0041] Similarly to the first test press arrangement with compression rollers 36, 38 as first test press tools, the second and third test press arrangements shown in FIG. 1 can be used to carry out test pressing. In this case, the test pressing positions to which the punch pairs are led are different, for example by corresponding rotations of the rotor. In particular, the punch pairs for carrying out test pressing with the second test press arrangement with compression rollers 40, 42 as second upper and lower test press tools 40, 42 are placed in the rotational position of the rotor that corresponds to the minimum spacing of the upper and lower compression rollers 40, 42. As soon as this position is reached, it is also possible to carry out test pressing with the second test press arrangement in the manner described above with the first test press arrangement.

[0042] A test press can therefore be carried out with a third test press device, the test press position then corresponding to the position of the punch pair shown at the far right of Fig. 1. As soon as this position is taken up, the third test press tools 54, 56 can be moved apart, if necessary, by means of the test press drive 58, and after filling the receptacle 12 with the material to be pressed, a test press can be carried out again, by causing the third test press tools 54, 56 to be pressed towards each other by means of the associated test press drive 58. It will be understood that for this purpose the lower press punch 16 is moved further downwards so as to be able to fill the receptacle 12 up to the desired filling height.

[0043] As explained, the rotary press according to the invention can be used to carry out test pressings with different pressing force curves. It is also possible to provide a pressing force sensor in the region of the test pressing device of the rotary press described above in order to measure the pressing force during the test pressing. In this way it is possible to ensure that the desired pressing force is reached and not exceeded.

[0044] FIG. 2 shows different possible pressing force curves, for example over time. From the left, FIG. 2 shows a sinusoidal pressing force curve, a sawtooth pressing force curve, a multiple pressing force curve and a rectangular pressing force curve. The multiple pressing force curves can simulate, for example, pressing on a rotary press with a pre-pressing device and a main pressing device, through which the pressing punch passes over time during its rotation. In the third diagram from the left in FIG. 2, the different heights of certain pressing force curves simulate a lower pressing force in the area of ​​the pre-pressing device compared to the main pressing device. [Explanation of symbols]

[0045] 10 Die Plate 12 Receptacle 14 Upper press punch 16 Lower press punch 18 Upper punch guide 20 Lower punch guide 22 Upper control cam element 24 Lower control cam element 26 Filling equipment 28 Filling Reservoir 30 Filling chamber 32 Filling tube 34 Main press unit 36, 40, 54 Upper Compression Roller / Test Press Tool 38, 42, 56 Lower Compression Roller / Test Press Tool 44 Discharge device 46 Scraping device 48 pellets 50 Ejector 52 Control device 58 Test Press Drive 60 Connection

Claims

1. 1. A method of test pressing pellets (48) in a rotary press comprising a rotary driven rotor with upper and lower press punches (14, 16), upper and lower punch guides (18, 20) for said upper and lower press punches (14, 16) and a die plate (10) between said punch guides (18, 20), said upper and lower press punches (14, 16) interacting with receptacles (12) of said die plate (10) in a production mode of said rotary press, further comprising a filling device (26) whereby said receptacles (12) are filled with material to be pressed in said production mode of said rotary press, and further comprising a pressing device (34) with upper and lower press tools interacting with said upper and lower press punches (14, 16) to press material present in said receptacles (12) into pellets in said production mode of said rotary press, characterized in that the method comprises the following steps: - filling the receptacle (12) with the material to be pressed; - directing a punch pair consisting of an upper and a lower press punch (14, 16) assigned to the receptacle (12) of the die plate (10) into a test press position in which the upper press punch (14) is located in the collision area of ​​an upper test press tool (36, 40, 54) of a test press device of the rotary press and the lower press punch (14) is located in the collision area of ​​a lower test press tool (38, 42, 56) of the test press device; - moving the upper test press tool and the lower test press tool (38, 42, 56) relative to one another using a test press drive (58) of the test press apparatus such that the upper and lower test press tools (36, 40, 54, 38, 42, 56) cause the upper press punch (14) and the lower press punch (16) to press against one another in the receptacle (12) of the die plate (10) to press the material filled in the receptacle (12) into test pellets (48).

2. 2. The method according to claim 1, characterized in that during the test pressing a pressing force and / or a parameter characterizing the pressing force is determined, and when a predetermined value of a predetermined pressing force and / or a parameter characterizing the pressing force is reached, the test pressing is terminated by moving the upper and lower test press tools (36, 40, 54, 38, 42, 56) apart.

3. 3. The method according to claim 2, characterized in that the parameters characterizing the pressing force are the web height, the pressing force curve and / or the pressure holding time at a given pressing force.

4. 4. The method according to claim 2, characterized in that the pressing force and / or a parameter characterizing the pressing force are taken into account for setting the rotary press for the production mode.

5. 5. The method according to claim 1, wherein only those punch pairs assigned to the receptacles (12) of the die plate (10) are installed on the rotor during the test press.

6. 6. The method according to claim 1, wherein the material to be pressed during the test press is filled manually into the receptacle (12).

7. 7. The method according to claim 1, characterized in that several test presses are carried out and the pressing force curve and / or the punch path curve are varied by varying the drive speed of the test press drive.

8. 8. The method according to claim 1 , characterized in that a sinusoidal and / or sawtooth and / or rectangular pressing force curve and / or punch path curve is set by setting the drive speed of the test press drive in the context of the test press or in the context of a plurality of test presses.

9. 9. The method according to claim 1, characterized in that the upper and lower test press tools are moved away from each other by means of the test pressed drive after a first test pressing step and then moved towards each other again by means of the test press drive, such that the upper press punch (14) and the lower press punch (16) are pressed against each other in the receptacle (12) of the die plate (10) by the upper and lower test press tools to further press the material filled in the receptacle (12) into test pellets.

10. 10. The method according to one of the preceding claims, characterized in that it is carried out by means of a rotary press according to one of the preceding claims.

11. 1. A rotary press comprising: a rotary driven rotor with upper and lower press punches (14, 16); upper and lower punch guides (18, 20) for said upper and lower press punches (14, 16); and a die plate (10) between said punch guides (18, 20), said upper and lower press punches (14, 16) interacting with receptacles (12) of said die plate (10) in a production mode of said rotary press; further comprising a filling device (26) for filling said receptacles (12) with material to be pressed in said production mode of said rotary press; and further comprising a pressing device comprising upper and lower press tools interacting with said upper and lower press punches (14, 16) to press material in said receptacles (12) into pellets in said production mode of said rotary press, The rotary press further comprises a test press device, the test press device comprising an upper test press tool (36, 40, 54) and a lower test press tool (38, 42, 56), for test pressing, the upper test press tool (36, 40, 54) interacting with an upper press punch (14) assigned to a receptacle (12) of the die plate (10), the lower test press tool (38, 42, 56) interacting with a lower press punch (16) assigned to the same receptacle (12), the upper and lower and a test press drive which moves the upper test press tool (36, 40, 42, 54, 56) and the lower test press tool (38, 42, 56) relative to each other for test pressing, such that the upper press punch (14) and the lower press punch (16) are pressed against each other in the receptacle (12) of the die plate (10) by the test press tool (36, 38, 40, 42, 54, 56) to press the material filled in the receptacle (12) into a test pellet (48).

12. 12. The rotary press of claim 11, wherein the test press drive comprises an electric drive or a hydraulic drive.

13. 13. Rotary press according to claim 11 or 12, characterized in that the rotary press comprises a control device (52) designed to control the test press drive.

14. 14. A rotary press according to claim 11, characterized in that the upper and lower test press tools (36, 40, 54, 38, 42, 56) are constituted by upper and lower press tools of the pressing device.

15. 14. A rotary press according to claim 11, characterized in that the upper and lower test press tools (36, 40, 54, 38, 42, 56) are test press tools configured separately from the pressing device (34).

16. 16. A rotary press according to one of claims 11 to 15, characterized in that the upper and lower test press tools (36, 40, 54, 38, 42, 56) are constituted by upper and lower compression rollers (36, 40, 54, 38, 42, 56).

17. A rotary press according to one of claims 11 to 16, characterized in that it is designed to carry out the method according to one of claims 1 to 10.

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