Method for test pressing pellets in a rotary press

A method for test pressing pellets in a rotary press comprising a rotationally driven rotor with upper and lower pressing punches, an upper and lower punch guide for the upper and lower pressing punches and a die plate between the punch guides, wherein in production operation of the rotary press the upper and lower pressing punches interact with receptacles of the die plate, further comprising a filling apparatus into which material to be compressed is filled into the receptacles during production operation of the rotary press, further comprising a pressing apparatus with an upper pressing unit and a lower pressing unit, which interact with the upper and lower pressing punches during production operation such that the pressing units compress material located in the receptacles into pellets, characterized in that the method comprises the following steps:

• a punch pair of an upper and lower pressing punch assigned to a receptacle of the die plate is brought into a dosing position in which the upper pressing punch is moved upward out of the receptacle and the lower pressing punch is partially located in the receptacle, such that the lower pressing punch presets a maximum fill height of material to be compressed in the receptacle,
• material to be compressed is filled into the receptacle,
• the pressing units of the pressing apparatus are moved relative to one another such that an expected web height of a pellet to be manufactured in the test pressing is reached before the punch pair exceeds the place of the smallest distance between pressing units during a rotation of the rotor,
• the rotor is placed into rotary motion such that the punch pair comes into contact with the pressure units for compressing the material filled in the receptacle into a pellet, wherein the pressing force and/or a parameter characterizing the pressing force is determined,
• upon reaching a preset pressing force and/or a preset value of the parameter characterizing the pressing force, the rotor is arrested and rotated in the opposite direction, such that the punch pair comes out of contact with the pressing units (36, 38).