Process Parameters

Define the filling, packing, cooling and machine parameters as required for the molding process. Default units shown are MKS (m kg N s).

Location: Molding ribbon

Stage Parameters

Use the Stages tab to define parameters for the Filling, Packing, and Cooling phases of the analysis.

Filling

Select a filling option based on time, flow rate or inlet speed, and enter a value.
Filling Parameter Description
Filling Time Enter the exact time required for the filling process.
Flow Rate Enter the volumetric flow rate at the inlet. The flow rate is area * velocity..
Inlet Speed Enter the inlet speed.
V/P Switchover Point Set the transfer point from the filling stage (velocity) to the packing stage (pressure-driven flow) based on your selection of one or more of the following criteria:
  • Percentage filled volume: Set the transfer to occur when the defined percentage of the model volume is filled. Enter the percentage or use the default value.
  • Percentage max machine pressure: Set the transfer to occur when the plastic injection pressure reaches the defined percentage of the machine’s pressure limit. Enter the percentage or use the default value.
  • Specified Pressure: Set the transfer to occur when the defined injection pressure is reached at the inlet face. Enter the pressure or use the default value.
  • Percentage max clamp force: Set the transfer to occur when the defined percentage of the machine’s maximum clamp force is reached. Enter the percentage or use the default.
Start holding at Enter the percentage of the volume filled to define the transfer position from the first-stage injection (speed) to the second-stage injection (pressure control).
Holding & packing pressure Specify a holding pressure or a percentage of the maximum filling or injection pressure.
  • Pressure Percentage: Enter a percentage of the maximum filling pressure that is to be maintained in the cavity. The Max filling pressure is defined on the Stages tab.
  • Pressure: Enter a specific holding pressure.
  • Max. Machine Pressure Percentage: Enter a percentage of the maximum injection pressure that is defined on the Machine tab.
Stop filling when Select one or both options to indicate the transfer point to the packing stage.
  • Volume filled: Select to stop filling once the volume in the cavity reaches the percentage specified.
  • Time: Select to stop filling once the specified duration of time is reached.

Packing

Define the time and pressure parameters for the Packing process of the analysis.
Packing Parameter Description
Pressure hold time Set the time to apply packing pressure at the inlet. The packing stage continues until the pressure reaches zero throughout the cavity or until the max packing time is reached.
Max packing Time Set the maximum duration for the the packing stage of the analysis.

Cooling

Select whether to end the cooling phase based on an Ejection Temperature or End Time. If both options are selected, cooling will stop when either value is reached.
Cooling Parameter Description
Ejection Temperature Select this option to stop the cooling phase when the temperature throughout all part cavities is below the defined temperature. Enter a temperature or use the default value.
End Time Select this option to stop the cooling phase after the specified period of time. Enter the time or use the default value.

Machine Parameters

Use the Machine tab to define the stroke volume, injection pressure, flow rate, and clamp force required for the molding machinery.

Machine Parameter Description
Max stroke volume Enter the maximum volume of the extruder when the screw is fully retracted. This does not include the nozzle attached to the barrel, but only the volume represented for the range of travel for the screw.
Max injection pressure Enter the maximum material pressure that the machine can produce with the current screw. This pressure can be calculated from the maximum hydraulic pressure multiplied by the screw’s intensification ratio, for example: (Hydraulic: 2,000psi) * (IR = 3:1) = 6,000psi.
Note: The injection pressure is normally based on the force of the reciprocating screw.
  • Lower diameter (A): Max Injection Pressure is approximately 1800 - 2400 bar.
  • Medium diameter (B): Max Injection Pressure is approximately 1500 - 1800 bar.
  • Higher diameter (C): Max Injection Pressure is approximately 1300 - 1500 bar.
Max injection flow rate Enter the maximum volumetric flow rate specific to the molding machinery in use (A·v).
Max clamp force Enter the maximum force required to keep the mold closed during the injection process (N). This is the maximum clamp force for the machine in Newtons. A value of 5,000,000 N is equivalent to 560 Tons (Imperial).
Note: The two halves of the mold will try to expand due to the pressure exerted on them. Insufficient clamping force can result in a flash defect.
Stop analysis if machine settings are exceeded Select this option to stop the simulation if any machine parameter exceeds its specified maximum value.