Izgara şeklinde dielektrik algılayıcı ile gerçek zamanlı reçine transfer kalıplama üretim usulünün izlenmesi

A grid of fifty dielectric sensors is embedded in mold walls to monitor the Resin Transfer Molding (RTM) process. The capacitance of each sensor increases as resin occupies the space between the upper and lower sensor plates, making it possible to monitor mold filling. After complete mold filling, the same sensors are used to monitor the cure level of the resin since the capacitance decreases with curing. Monitoring of mold filling can be used as an in-situ data for a process control to prevent dry spots in the part; and monitoring of resin cure level can be used to determine the minimum time required before de-molding the part once the green strength and stiffness are achieved. In previous studies, a small number of dielectric sensors were used in an entire mold cavity. As experimentally shown in this study, these large-plate or lineal dielectric sensors may mislead the user since a sensor measures the total fraction of the sensor?s plate area occupied by resin but not the resin?s whereabouts on the sensor. To avoid ambiguity and yet maintain detailed flow monitoring, a grid of smaller dielectric sensors was used in this study. The grid was made at the projections of vertical and horizontal electrodes embedded in the two opposite mold lids, to avoid the complexity of embedding separate sensors. The developed sensor operation system eliminated the tedious and costly manufacturing of conventionally shielded sensors. The success of the developed sensor system was demonstrated in RTM experiments for several different case studies.