If high-quality surfaces or fine microstructures are to be achieved in plastics technology, more and more toolmakers and injection moulders are relying on the Z-System from hotset. Especially in the mass production of moulded parts for the consumer and automotive industries, this highly flexible solution for partial and cyclic cavity temperature control offers convincing benefits. Now there is another one: A new thermal sensor with an extremely short response time. With this innovative in-house development, hotset gives its Z-System even higher process accuracy.
“All commercially available cavity sensors are now too slow and can no longer keep up with the high dynamics of our Z-System’s processes for partial and cyclic cavity temperature control. Based on our internal development and engineering expertise in the field of sensor technology, we have implemented our own, extremely fast reacting thermocouple in recent months,” reports hotset project manager René Schlöter. He addresses an aspect that is of fundamental importance for almost every dynamic or variothermal mould tempering system in injection moulding technology: The use of cavity sensors for measurement of temperature changes in the tool, which prove themselves with very short response times. The more responsive and agile such a heat sensor works, the more precisely the temperature control can be controlled and monitored. “Thanks to our new cavity sensor, our Z-System jumps to the next higher performance level in terms of measurement and control technology. This applies to both control modes of partial-cyclic temperature control – i.e. both the time-controlled and temperature-controlled mode,” explains René Schlöter. In both cases, the use of the new thermocouple leads to a further improvement in process reliability and repeatability of the high-speed solution from Lüdenscheid. For the user of the Z-System this means that he receives more precise information about partial temperature control. Even more direct and even more accurate control of the Z-System can influence the level of detail and the surface quality of its injection-moulded part.
As part of the tool-specific and customised installation of the Z-System – very similar to the installation of a hot channel system – the new hotset thermocouple is brought as close as possible to the area in the cavity wall to be tempered. “This means that the sensor always sits directly in the dynamic zone of the partial-cyclically tempered mass, which is crucial to the surface quality of the injection-moulded part,” emphasises René Schlöter. Thanks to its fast response, the new cavity sensor detects even the smallest temperature changes and deviations, virtually in real-time. In a fraction of a second, the measured values are then forwarded to the Z-System controller and graphically processed for visualisation.
In addition to the experience it has gathered in the field of thermodynamics, hotset has also used its in-house expertise in sensor manufacturing and calibration technology to develop its new cavity sensor. Series production takes place in hotset’s modern assembly lines in the Maltese production plant. The new thermocouple is initially available in the standard industry types K and J – both as a component of the Z-System and as an independent supply part for the manufacturers of other dynamic or variothermal tempering products. The new heat sensor from hotset can be flexibly adapted to different installation situations. It is very important, especially in the case of rapid thermodynamic processes, to carry out the integration of the cavity sensor in terms of its positioning and thermal coupling in the most practicable and reproducible way possible.
The Z-System was first introduced in autumn 2016 and has since been used by increasing numbers of toolmakers and injection moulders. At the same time, hotset engineering is continuously working on the further development of this innovative solution for partial and cyclic cavity temperature control. “With the integration of our new cavity sensor, we have taken an important step, which also makes us independent from the usual standard offers of the market. But because we collect new ideas from almost every Z-System project, we will not run out of substance for further stages of development,” says René Schlöter.