Improvement on µ-injection process

The micro injection processes have been tackled by the project too, defining the resolution of the manufacturing problems addressed by EuroOrtodoncia as the objective for some RTD tasks. Some of the problems found when manufacturing transparent bracket lids are the premature erosion of the mould, the occurrence of unfilled parts, the appearance of flashing on the parts or the trapping of parts on the mould. As the first step, a new mould concept has been developed by EuroOrtodoncia and Tekniker. Besides providing the possibility to introduce sensors for the in-line monitoring of the micro injection process, the part location on the new mould would allow for higher throughput while avoiding the appearance of premature wearing on the moulding parts. The new part location involved considerable difficulties on the accurate manufacturing of the mould, but it was undertaken by the project partners KUL and Sarix with great success. After the inclusion of sensors on a test mould for the monitoring of process signals as pressure and temperature, IK4-Tekniker has carried out an experimental analysis concerning the effect of the values taken for different process signals and the quality generated on the micro injected part. This way, it has been possible to define several relationships between the process signals obtained on different mould locations and the obtained part quality. Besides, EuroOrtodoncia has worked on the implementation of an in-line inspection system for every manufactured part on their manufacturing chain. This system obtains images from the gripper that takes the parts away from the mould and identifies the presence of the part together with some injection related problems as flashing. Thanks to this system, it is possible to automatically link the process data with the obtained part quality for the generation of an extensive manufacturing data log for its later treatment. Both the actual manufacturing data obtained from the monitoring and the empirical modelling for the part quality previously carried out has been implemented by the University of Leuphana on a software module for the analysis of the micro injection process. Analysing the historical process monitoring data, this tool can identify different trends on the manufacturing quality for the generation of statistical models that could represent the actual process behaviour. Then, identifying deviations on the process parameters that could generate defective parts, and taking into account the high part throughput on this process, this tool can aid on the avoidance of high volume part scrapping.