Improving the process capability in injection moulding by the use of process data and a novel approach for controlling the injection stroke
Within this thesis it will be investigated in what extend the information available in the drives system of electromechanical injection moulding machines can be used to increase the process capability. Therefore several process parameters that are based on the operating parameters of the electrical drive system in injection moulding machines are defined. Detailed test series are carried out to investigate the parameters reactions on a simulated feedstock induced process disturbance. The process parameters that are based on the dynamic process phases like injection and plasticizing show the highest reactions. After these test series the process parameters are used as input quantities in a quality control loop that is based on statistical process models.
Furthermore a new approach for controlling the injection stroke is presented. Compared to the standard injection moulding process with its velocity and pressure controlled injection stroke the new process is completely specified by a velocity profile for the whole injection movement. A changeover point in the classical sense where the closed-loop control is switched from velocity control to pressure control is not to happen in this process. The results show that changes in the closing behaviour of the non-return valve cause high pressure variations in this process. Based on the experimental results there are prospects presented that use an in cycle adaption of the velocity profile of the injection stroke to compensate the effects of feedstock induced process disturbances.Lesen Sie die deutsche Zusammenfassung auf Kunststoffe.de
Injection moulding, Injection moulding machines, Electromechanical injection moulding machine, Process capability, Reproducibility, Process parameter, Process variables, Quality control, Batch variations, Residual humidity, Energy balance, Drive systems
Institute / chair: Lehrstuhl für Konstruktionslehre und Kunststoffmaschinen, Universität Duisburg-Essen
Technical consultant for expert services: Prof. Dr.-Ing. Johannes Wortberg (Betreuer), Prof. Dr.-Ing. Dr.-Ing. E.h. Walter Michaeli
Publication year: 2009
Provider: Wissenschaftlicher Arbeitskreis Kunststofftechnik (WAK) / Kunststoffe.de
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