METHOD OF OPERATING A ROTARY TABLET PRESS AND ROTARY TABLET PRESS

Abstract

The invention relates to a rotary tablet press and method of operation. The rotary tablet press includes a rotor that is rotatably driven that is coupled to a die plate with holes. Upper and lower punches are assigned to the holes and rotate synchronously with the die plate. A pressing apparatus presses the punches into the holes to press the filling material added to the holes. An ejector apparatus ejects the tablets pressed into the holes. A control apparatus automatically changes the rotary speed of one or more components in response to changes to components of the rotary tablet press and process components upstream or downstream of the rotary tablet press.

Claims

1. A method for operating a rotary tablet press, the method comprising: driving a rotor at a rotor rotary speed, the rotor including a die plate with holes; rotating upper and lower punches synchronously with the die plate, the upper and lower punches being assigned to the holes; moving the upper and lower punches in an axial direction with respect to the holes by upper and lower control elements; filling the holes with filling material dispensed from a filling apparatus; agitating the filling material with a filling wheel, the filling wheel having a filling wheel rotary speed and agitator blades arranges around a perimeter of the filling wheel; pressing at least one of the upper and lower punches into the holes in order to press the filling material added to the holes; ejecting tablets pressed into the holes; and automatically changing the filling wheel rotary speed according to at least one stored adaptation instruction in response to a change in the rotor rotary speed during operation of the rotary tablet press, and automatically changing the rotor rotary speed according to at least one stored adaptation instruction in response to a change in the filling wheel rotary speed during operation of the rotary tablet press.

2. The method according to claim 1, wherein the at least one stored adaptation instruction is saved in a form of a mathematical function, a characteristic, or a matrix of key figures in a control apparatus.

3. The method according to claim 1, wherein different adaptation instructions are saved for different filling materials to be pressed in the rotary tablet press.

4. The method according to claim 1, wherein a change in at least one of the rotor rotary speed and the filling wheel rotary speed occurs automatically upon a state change of process components connected to the rotary tablet press.

5. A rotary tablet press comprising: a rotor configured to be rotatably driven at a rotor rotary speed; a die plate with holes, the die plate coupled to the rotor; upper and lower punches that are assigned to the holes and configured to rotate synchronously with the die plate; upper and lower control elements configured to control axial movement of the upper and lower punches; a filling station with a filling apparatus for filling the holes with filling material, the filling apparatus further comprising, a filling chamber, a filling wheel positioned in the filling chamber and configured to be rotatably driven at a filling wheel rotary speed, the filling wheel including a plurality of agitator blades arranged around a perimeter of the filling wheel; a supply opening configured to connect to the filling chamber, and a filling opening configured to align with one or more of the holes, a pressing station positioned downstream of the filling station, the pressing station including a pressing apparatus configured to press at least one of the upper and lower punches into the hole when passing through the pressing station in order to press the filling material added to the hole, and wherein the agitator blades are configured to pass over the filling opening during rotation of the filling wheel; an ejector station positioned downstream of the pressing station, the ejector station including an ejector apparatus for ejecting tablets pressed into the holes; and a control apparatus configured to store at least one adaptation instruction for operating the rotary tablet press, and wherein the control apparatus is configured to automatically change the filling wheel rotary speed according to the at least one adaptation instruction when the rotor rotary speed changes, and wherein the control apparatus is configured to automatically change the rotor rotary speed according to the at least one adaptation instruction when the filling wheel rotary speed changes.

6. The rotary tablet press according to claim 5, wherein the at least one adaptation instruction is saved in a form of a mathematical function, a characteristic, or a matrix of key figures in the control apparatus.

7. The rotary tablet press according to claim 5, wherein different adaptation instructions are saved in the control apparatus which correspond to different filling materials to be pressed in the rotary tablet press.

8. The rotary tablet press according to claim 5, wherein the control apparatus is configured to automatically change at least one of the rotor rotary speed or the filling wheel rotary speed upon a state change of at least one process component connected to the rotary tablet press.

9. The rotary tablet press according to claim 5, wherein the upper and lower control elements are upper and lower control cam elements.

10. The rotary tablet press according to claim 5, wherein the pressing apparatus comprises a pre-pressing apparatus and a main pressing apparatus.

11. The rotary tablet press according to claim 5, wherein the pressing apparatus comprises at least one upper pressing roller and at least one lower pressing roller.

12. The rotary tablet press according to claim 5, wherein the ejector apparatus comprises a scraper that is arranged stationarily above the die plate and is configured to guide the tablets to a tablet discharge.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0018] FIG. 1 shows a schematic view of a rotary tablet press according to the invention with a flattened depiction of the rotor.

DETAILED DESCRIPTION OF THE INVENTION

[0019] The rotary tablet press comprises a rotor rotatably driven by a rotary drive (not shown) at a rotor rotary speed with a die plate 10 which has a plurality of holes 12. Furthermore, the rotor comprises a plurality of upper punches 14 and lower punches 16 that rotate synchronously with the die plate 10. One pair consisting of an upper punch 14 and lower punch 16 is assigned to a hole 12. The axial movement of the upper punch 14 and lower punch 16 during the rotation of the rotor is controlled by upper control cam elements 18 and lower control cam elements 20. The rotary tablet press further comprises a filling station 22 with a filling apparatus which has a filling chamber 24 in which a filling wheel 26 is arranged with a plurality of agitator blades 28 arranged on the perimeter. The filling wheel 26 is driven by a rotary drive (not shown) at a filling wheel rotary speed. Moreover, the rotary tablet press comprises a pressing station 30. The pressing station 30 possesses a pre-pressing apparatus with an upper pre-pressing roller 32 and a lower pre-pressing roller 34, as well as a main pressing apparatus with an upper main pressing roller 36 and a lower main pressing roller 38. Furthermore, the rotary tablet press comprises an ejector station 40, in the present case with a scraper 42 which supplies the tablets 44 produced in the rotary tablet press to a tablet discharge 46 for further processing.

[0020] A control apparatus for operating the rotary tablet press is shown with reference number 48. The control apparatus 48 is connected by lines (not shown) to, inter alia, the rotary drive of the rotor and the rotary drive of the filling wheel 26. In an embodiment of the control apparatus 48, a plurality of adaptation instructions are saved for different filling materials to be used in the rotary tablet press for adapting the filling wheel rotary speed upon a change in the rotor rotary speed.

[0021] During operation of the rotary tablet press, the rotor is rotatably driven at a rotor rotary speed set by the control apparatus 48. At the same time, the filling wheel 26 is rotatably driven at a filling wheel rotary speed controlled by the control apparatus 48. During the rotation of the die plate 10, the holes 12 run below a filling opening of the filling chamber 24. The filling material to be pressed is added to the holes 12 through this filling opening. The filling height is specified by the lower punch 16 which partially enters the holes 12. In the region of the pressing station 30, the filling material located in the holes 12 is pressed by the upper punch 14 and lower punch 16, i.e., successively by the pre-pressing rollers 32, 34 and main pressing rollers 36, 38. After pressing the filling material, the upper punches 14 are withdrawn from the holes 12, and the produced tablets 44 are ejected by the lower punches 16 onto the top side of the die plate 10 such that they are scraped off of the top side of the die plate 10 by the scraper 42 and supplied to the tablet discharge 46 for further processing.

[0022] Other process components can be upstream and/or downstream from the rotary tablet press. As mentioned at the onset, the process components upstream from the rotary tablet press can, for example, be mixing apparatuses, granulation apparatuses or drying apparatuses. As also mentioned at the onset, the process components downstream from the rotary tablet press can, for example, be packaging machines or tablet coaters.

[0023] If, for example, a state change occurs in process components connected to the rotary tablet press, the rotor rotary speed is changed by the control apparatus 48, in particular automatically. At the same time, the control apparatus 48 automatically adapts to the filling wheel rotary speed corresponding to the adaptation instruction appropriate for the filling material used. This, therefore, ensures that even in the event of a change in the rotor rotary speed which may be necessary, optimum production quality is ensured at all times, and without interrupting production.