COMPUTER-SIMULATION AND CONTROL FOR PRODUCT QUALITY IN INJECTION-MOLDING

The use of computers in plastics processing has continued to grow in p arallel with rapid expansion of computer availability and computing po wer. One of the main areas of application is in computer simulation of the injection molding process where more demanding applications relat e to the simulation of molding of complex-shaped moldings. Recent deve lopment include the use of boundary fitted curvilinear coordinates, th e incorporation of fountain flow, and the coupling of crystallization kinetics within the transport equations. Applications in computer cont rol relate to the control of pressure and temperature throughout the i njection molding process, self-tuning control, physically-based dynami c models, and the control of properties of the molding, e.g. the weigh t of the article. Recent developments relate to the application of inv erse modeling. An example is given of the use of inverse modeling of t hermal stresses to predict or optimize thermal or pressure history dur ing molding.