Special machines - Twist – the right turn against adhesion

In this procedure, the pressing tools below or just after the main compression rollers are counter-rotated. The brief rotation under a specific load means that the pressing material that is adhered to the punch surfaces is released and pressed back into the surface of the tablet.

The TWIST function has proven beneficial for the following products:

The benefits

Mechanical procedure that does not require additives
No additional soiling of the tablet machine
Permanent or partial rotation of the tools is possible
Clean punch and smooth, polished surfaces of the tablets
Suitable for tablet diameters of 2 to 44 mm

The KORSCH TWIST function is protected by copyright.

Caution: This procedure can only be used for round, neutral tools without engravings or score lines. The max. force of pressure of the machine in conjunction with the TWIST function is limited to approx. 50 kN.

The alternatives

KORSCH also has other possibilities for preventing pressing masses adhering to the surfaces of the punches and the die plate:

Hard chrome plating

In the case of easily adhering pressing masses, it may be sufficient to simply apply hard chrome plating to the polished pressing tools.

Liquid spraying device
To avoid adherence to the wall of the die plate, it has proven beneficial to spray the lower punches with a thin oil that is approved for use with food. The lower punches are sprayed with a fine mist of oil at the lowest position by means of a micro-spray nozzle. When the lower punch moves, the oil is automatically transferred to the die plate wall. The thin layer of oil prevents the pressing material adhering to the wall of the die plate.
The delivery scope also includes a pressurised vessel (5 / 10 litre.) for the lubricant, a compressed air connection with the supply unit including a pressure reducer (the compressed air 3.5 - 7 bar must be supplied by the operator), the airless spray nozzle with a holder, oil stripper and oil recirculation unit in a collection tank.
Disadvantage: Not all pressing masses allow the application of liquid lubricants; also this leads to heavier soiling of the machine.

Powder spray device
In this procedure, an air-stearate mist is blown onto the punch and wall of the die plate after the tablet stripper and before the filling device. The fine stearate dust adheres to the surface of the tool and prevents the pressing material adhering. The stearate quantity can be set very finely to minimise soiling of the machine. Excess stearate is suctioned off. The system works very effectively.
Disadvantage: Stearates do not dissolve in water and can therefore not be used for all products. Despite the dust extraction, additional soiling of the machine caused by the stearate mist cannot be avoided.

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