Smart Molding International 2-2021

molding technology 37 www.smart-molding.com T ry to imagine the most complex part ever: it is a delicate trade-off of polymer selection, processing, part design and mold design. Several elements could affect the injection process, from the issues related to the Injection Molding Machine to the molding material, but how to detect them? Thanks to the combination of the right technologies, defects on the molded parts can be prevented ensur - ing higher quality output in less time. One of the main causes of process variability could be related to the Injec - tionMoldingMachine for example: if the InjectionMoldingMachine components - such as the screw, the barrel and the check ring – showsigns ofwear, the injec - tion process could vary significantly. The result is that the inconstancy produced during the injection/packing phase or the material dosage could cause few defects on the molded parts. Another element that of - ten affects the injection pro - cess is the viscosity variation of the molding material. The causes of these anomalies? Fewtimes was observed that different batches of plastic material could behave slight - ly differently during the in - jection process. In addition, an eventual percentage of recycled material could be one of the causes of process variability. How to detect these problems, avoiding process drift? Thanks to pressure sensors, you can get a di - rect feedback of process constancy by monitoring the real polymer sta - tus in the cavity. Moreover, you can highlight if some irregular cycles oc - cur, in order to determine which cycle lies outside of a specified tolerance range. Thanks to pressure sensors you are able to define if the process is gradually going to drift, or rather, when several cycles are getting far from the ideal process. Using mold based sensors allows for valve gates to be triggered from mold born events and not based on screw position or time. This allows the pro - cess to adapt to actual conditions. The winning combination of pres - sure sensors and FLEXflow Evo – the electrically driven valve gate system – allows to get a precise control over the whole injection process helping to detect the problems related to the molding material and the injection molding machine. The servo driven valve gate technol - ogy is designed for the independent adjustment of each valve pin with pre - cise control of stroke and force during opening and closing phases. This solu - tion assures accurate, easy to operate, flexible control of pressures and flow rates at each individual gate providing far superior flexibility and minimizing the process variability. Pressure sensors together with FLEXflow Evo allow to highlight the polymer status in the mold cavity by delaying or bringing forward the opening/closing phase. This success - ful combination ensures not only the maximum process reliability and re - peatability but also a uniform quality with a minimal scrap. HRSflow www.hrsflow.com The winning combination to keep the injection process under control Picture: HRSflow What are the main process anomalies that commonly affect injection molders and how to detect them? HRSflow, part of the worldwide com - pany INglass Group, designs and manufactures hot runner systems for a wide range of applications in the plastic injection molding industry. In the Automotive industry four megatrends are disrupting the entire landscape: connectivity, autonomous driving, electrification and ride-shar - ing. HRSflow can strongly support this transformation with IMD, FIM and ICM solutions combined with our FLEXflow Evo Technology: the servo driven valve gate system that changed the injection molding world.