For such purposes, developed high temperature (HT) piezoelectric film ultrasonic transducers (UTs) [23, 24] have been integrated onto the mold insert of a COIM machine.
In the experiments, injection grade ABS (Magnum 342EZ) for the skin and second core and polycarbonate (PC: CALIBRE 200) for the first core were employed to produce COIM parts.
Figure 3a and b show the paths of ultrasonic observed at the UT locations with COIM using an ultrasonic pulse-echo technique, where only first core arrives at the UT1 located near the end of the mold cavity in Fig.
Figure 4a and b show the typical results of acquired signals with the UT1 and UT2, respectively, during one cycle of COIM when the setting core volume percentage was 58% (part no.
Thus, a real-time ultrasonic thickness measurement of the parts, involving the skin and core layer thicknesses, was conducted during COIM process.
In COIM, the dimension of the core in the molded part affects the performance and mechanical properties of molded parts.
Real-time, nonintrusive, and nondestructive monitoring of COIM process has been performed using integrated HTUT sensors.
Therefore it is demonstrated that the presented integrated ultrasonic sensors and techniques might be an excellent approach to diagnose COIM processes, nondestructively and noninvasively during molding, to optimize the process parameters.