Complete pressing programs (optionally) with different pressing steps can be configured with our machines. Pressing steps mean a maintaining phase on differently high and freely selectable compression force levels defined in time. It can be defined for the press in question in the previously carried out determination of the test data how long a determined compression force level shall be maintained und which different levels shall be approached in the test (e.g. ten different steps) Moreover certain target temperatures are freely selectable which shall be approached by the machine during the pressing step. A lower subsequent temperature in the next step will cause cooling in the corresponding step. The time set for the step will determine the ramp inclination (refers to heating ramp and cooling ramp inclinations the same), Besides that, one or more relief impulses are freely selectable which the machine shall execute during the test setup. A zero number of relief impulses within a pressing step will cause skipping the relief defined for this step. Relief impulses or also degassing impulses may make sense if vapours caused by chemical processes will emerge from the test material or if the material shall be subject to a certain settling behaviour which shall be provoked by the momentary and specifically controllable interruption of the compression forces. In this context relief impulses will be defined by:
- Value of the programmed pressure loss in milliseconds
- Interval until the next pressure loss in seconds
- Number of impulses within a step as quantity
- Determination whether a relief shall take place or not
Practical experience has shown that it may make sense to define before starting a regular pressing program a melting phase (“starting phase” see above) which only will be defined by a target temperature and a minimum settable contact compression force which mainly shall guarantee the transition of the plate heat to the test material in order to allow for a good melting behaviour without or nearly without a compression force. Specially at granulate as test material it may make sense to melt the latter before pressing as otherwise undesirable impressions in the pressing plates may occur. If e.g. such a melting phase is not desirable due to time reasons, one may also skip this phase completely, starting at once the regular pressing program with phase 1. Besides that, a great number of further test parameters can be configured which can be defined by the user (the above figure can be continued for the plates 2 to 10) of a single pressing program. Already up to 20 different pressing programs have been designed in a configurable version. Pressing programs are saved in the control and therefore can be called and repeated accurately.