Competence in mixing
Herbst Maschinenfabrik - Buxtehude

Control technology

Mixing technology is increasingly under pressure to guarantee consistant mixing quality. The product quality should be ensured, both in the case of personnel change, as well as during frequent product changes. In addition, end users are increasingly demanding a proof of quality by requesting a mix protocol from the producer. This is not an issue with the assistance of control technology and control systems engineering. The program sequence can be organised product-related, so that the mixing process always runs at an optimum.

Modern sensor elements take into account and record important parameters, such as temperature, pressure and speed. The individual components of the mixer or a system such as the drive, vacuum pump, heater, homogeniser and shut-off devices can be addressed individually by the control unit. This enables a procedural optimal mixing- process. The stirrer speed can, for example, be regulated in accordance with the product viscosity or the shear sensitivity. The vacuum pump can be engaged for degassing the mixing product and absorbing additional mixing components. The metering, discharging and cleaning can be integrated into the program sequence, so that the operating personnel is not required to be in attendance at all time; several mixers can be operated at the same time or other work can be carried out. By implication, this is a time and cost saving aspect. Important phases of the program sequence can be acoustically or optically signaled for the operator. Data logging also enables optimum safety technology which, for example, switches off the stirrer where the temperature rises above that which is permissible.

The operation of the control system does not require any programming skills and is usually menu-driven on a touch panel. Current process parameters (e.g. speed, temperature and pressure) are always visible on the display. The visualization of the main components of a the system allows a good overview over the process sequence.

The process can be operated both, programmatically and manually.

The scheduled program can easily be adjusted to changing requirements at any time. This is important in the areas of research and development. The current parameters can be transferred to a PC via an interface for external data collection.

The basic programming of the program control is customised. The program sequences can be created, saved, modified and recalled for different products at any time. The operator can make changes to the program on the touch panel. Several user levels can be set up with password protection. It is also possible to set up a remote maintenance function (after access is activated by the system operator) for direct access for a programmer to intervene in the event of problems.