Process Constraints from Quality Requirements
The process constraints established from quality requirements, illustrated on the figure below, consist of five quantities:
•Minimum and maximum gate speed: The min and max gate speeds are converted to the corresponding pressure and shown on the diagram as horizontal lines extending across the figure. Part requirements dictate a minimum and maximum gate speed for satisfactory part quality and process operation and these quantities are displayed on the diagram as pressures.
•Maximum Fill Time: the maximum allowable fill time to achieve part quality requirements corresponds to the smallest acceptable volume flow rate shown as the vertical line in the diagram.
•Minimum and maximum static pressure: The two short horizontal lines illustrate static pressure constraint magnitudes. Such constraints follow from quality requirements as well. The static pressure limits are generally treated qualitatively, but they form an important part of the optimization approach used in the program.