Fill Settings PropertyManager

The Fill Settings define the injection molding process parameters such as Filling Time, Melt Temperature Mold Temperature, and Injection Pressure Limit.

To open the Fill Settings PropertyManager:

  • In the PlasticsManager, expand Process Parameters, and click Fill Settings.

Process Parameters

Filling Time Specifies the time it takes the molten plastic to fully fill the cavity.

The program calculates automatically the Filling Time based on the part geometry and the properties of the material you select.

Click Auto to enable editing of the Filling Time.

If you use the Advanced options below to control the filling process, the software recalculates the Filling Time.

The diagram shows the variation of injection pressure (y-axis) with respect to filling time (x-axis). The U-shape diagram indicates that the optimal filling time is located at the bottom of the curve. For short or very long filling times, higher injection pressure values are required.
Melt Temperature(oC) Specifies the temperature of the polymer at the injection location (or locations).

The default value for Melt Temperature is taken from the material database (see Polymer-Material Parameters tab of the selected material).

Click Reset to reset the Melt Temperature to its default value.
Mold Temperature(oC) Specifies the temperature that the mold is heated to.

The default value for Mold Temperature is taken from the material database.

Click Reset to reset the Mold Temperature to its default value.

If the mold temperature is not constant but varies with time, select Mold Temperature profile to enter the mold temperature data.
Injection Pressure Limit Specifies the maximum allowed value of the pressure of the polymer at the injection location (or locations).

If the pressure reaches the Injection Pressure Limit value, the inlet flow rate automatically reduces to a value corresponding to this limit, and the Filling Time is longer than the Filling Time value that is set.

You can adjust the default Injection Pressure Limit according to the capacity of your machine.

Click Reset to reset the Injection Pressure Limit to its default value.
Clamp Force Limit

Specifies the maximum allowed value of the force required to keep the mold closed. If the force reaches the Clamp Force Limit value, a warning alerts you in the Analysis Manager, and the analysis continues unimpeded.

You can adjust the default Clamp Force Limit according to the capacity of your machine.

Advanced

  Flow/Pack Switch Point (% Filled Volume) Controls the process changes from FLOW to PACK.

During FLOW, polymer is forced into the cavity at a given flow rate, regardless of pressure. To avoid a rapid pressure rise and potential damage to the machine, it is common to switch from FLOW to PACK just before the cavity becomes full, for example at 95% of the cavity volume.
  Temperature Criteria for Short Shots(oC)

If the temperature in the molten polymer is below this temperature value, a warning alerts you in the AnalysisManager.

If the temperature stays below this value for several iteration steps, a short-shot occurs. The polymer solidifies and the melt flow stops.
  Multi general Gate Flow-rate/Press control Available for shell analysis procedure only and multiple injection locations.

Equivalent

Distributes equal flow rates at each injection location, with potentially different resulting pressures.

Automatic

Balances the flow between injection locations to produce equal pressures, simulating the effect of a runner system.
  Gravity Direction: (Global) Defines the direction of gravity.

For example, if the model is oriented in the injection molding machine such that the positive Y- axis points upward, select the negative Y- axis for the gravity direction.

Gravity Direction is available for the solid analysis procedure.
Flow Rate Profile Settings Controls the flow rate during the filling of the cavity by defining a Flow Rate Profile based either on volume or time control.
  Volume control (Absolute control)/Base on machine max flow rate You can control the variation of Flow rate or Screw speed in terms of the percentage of filled cavity volume, or the screw position. By default you can enter five data pairs. You can increase the number of data pairs in Section num.

Flow rate (cc/sec) or (in3/sec)

Specifies the volumetric flow rate.

Flow rate (%)

Specifies the flow rate as a percentage of the Reference flow rate. For example, if the Reference flow rate (cc/sec) is 350, and you enter a flow rate of 80%, then the actual flow rate is 280 cc / sec.

Screw speed

Used together with the Screw diameter to calculate the flow rate (flow rate = Screw speed * Screw section Area).

Screw position

Used together with the Initial screw position to define the volume of material delivered to the cavity.

Volume (%)

The percentage of the filled cavity volume. Enter a value of 100% in the last table entry.
  • Specify an Initial screw position, if the Flow Rate depends on the screw position.
  • Specify a Reference flow rate (cc/s), if you define the flow rate as a percentage of the reference flow rate.
  • Specify a Screw diameter, if the flow rate depends on the screw speed.
  Time control (Relative control)/Base on filling time Specifies the profile of a relative flow rate versus the filling time or a percentage of the total filling time.

Filling Time (sec)

Displays the filling time from the Fill Settings PropertyManager. You can enter the filling time profile data in absolute (Time sec) or relative values (Time %).

Flow rate (%)

The Flow Rate (%) values you enter in the table are interpreted relative to each other. For example, if two data points are defined with Flow Rate values of 10% and 30%, the flow rate for the second data point is three times larger than the first flow rate value. The software calculates the actual volumetric flow rates for each data point to satisfy the given relative profile and the filling time for the cavity.
  Apply

Applies the current settings to the current of the flow rate profile.
Machine Database From the injection molding machine database, select an injection machine.

The injection molding machine database is provided as a reference only. The selection of any machine does not have any effect on the analysis settings or results. If you want to use any data from the machine database, enter the data into the Analysis Process parameters.

When you select a machine from the database, you need to copy the selected machine's parameters in the respective Fill Settings PropertyManager input fields. The software does not transfer the selected machine's default values for Injection Pressure Limit, Screw Diameter (Flow Rate Profile Settings dialog box), and Reference Injection Rate (Flow Rate Profile Settings dialog box) automatically.
  Viscoelastic Birefringence Calculation Activates the Birefringence calculation. Select a polymer that includes definitions for the Birefringence material parameters to use this feature.

These material parameters are the Leonov parameters in the Material Database / Polymer-Material Parameters.

Solver Settings

Options Provides access to the advanced solver settings. Accept the default values of the solver settings to produce the best results over a wide range of cases. For most analyses, you do not need to modify the solver settings.

See topic Advanced Settings for the Flow/Pack Solver.

Fiber Orientation Calculation

To improve the strength and performance of plastic products, many plastics contain fibers. The fiber percentage of each material is included in the polymer material database. Material data, such as viscosity coefficients, reflect the properties of a particular fiber % and polymer combination.

During cavity filling, the fibers become oriented along the flow directions. This produces changes in the microstructure that affect the mechanical properties and final dimensions of the product.

For polymer materials that have a % fiber value, select Fiber Orientation Calculation to compute fiber orientations during the simulation.

Current % Fiber based on Weight Specifies the percentage of fiber in the material based on weight.

For example: for 1 kg material with 200 gr of fiber, you enter 20 (%) for Current % Fiber based on Weight; If you select a polymer from the Material Database, the fiber percentage value is taken from the database.

Co-injection

In a co-injection simulation, the machine injects two polymers (or a polymer and a gas) sequentially into the cavity. Typically, the first material becomes skin and the second material fills the core. Co-injection is also used for Gas Assist injection molding, where you select a gas for the second material, and the part becomes hollow.

In the material dialog box, select Set Coinjection > 2nd, and select the second material from the plastics database.

2nd Material Melt Temperature

The default value is taken from the material database (see Polymer-Material Parameters tab of the selected material data sheet).

Venting Analysis

In general, the presence of air in the cavity is ignored during simulation. However, venting analysis allows you to include the effect of the air, and the pressure that it may exert on the melt front.

If you run venting analysis, you must define vent locations in the cavity (see Boundary Condition > Air Vents). Venting analysis identifies and tracks bubbles that may form and coalesce in the cavity away from air vents and computes the pressure that develops in them.

For the first analysis, it is recommended to not define any air vents. Use the Venting Pressure result to guide air vent placement, and avoid placing them where they are not required.

Cavity Initial Air Pressure (MPa) The initial air pressure when the cavity is empty is 14.71 psi or 0.1 MPa by default.
Cavity Initial Air Temperature () The initial air temperature in the cavity is the room temperature by default.

Mold-Melt Heat Transfer Coefficient

The heat transfer between the polymer and the mold walls varies during the different stages of the injection process:
  • During the filling stage, the polymer enters the cavity, and the heat transfer raises to the maximum value.
  • During the packing stage, the polymer is in contact with the mold walls, and the heat transfer stays at the maximum value.
  • During the ejection stage, the polymer shrinks during the pre- cooling time, and detaches partially from the mold walls. The heat transfer is reduced in this stage.

Reactive Control Type

Available only when you select a thermoset polymer material. Examples of thermoset material families available in the Plastics database include: BMC, EMC, and LSR.

In thermoset injection molding, the plastic in a liquid state (typically at room temperature or colder) is injected into a heated mold. The heat from the mold induces a chemical reaction that creates cross-links (permanent connections between molecular chains) in a process known as curing. Choose between two different options to determine the duration of the analysis.

Conversion

When selected, the Fill/Pack stage lasts until the analysis reaches the specified value for the Reactive Eject Conversion: (%).
Time When selected, you explicitly define the duration of the Fill and Pack phases. At the end of the analysis, you can review the curing conversion % to better understand whether your specification is appropriate.
Reactive Eject Conversion: (%) Specifies the required conversion degree. Available when you select Conversion.

Mold Temperature Profile

If the mold temperature is not constant but varies with time, select Mold Temperature profile.

Enter the mold temperature variation in terms of absolute time or as a percentage of the total process time. The total process time includes Fill, Pack, and Cool time.

For a more detailed consideration of mold temperature, you can perform a Cool simulation, where heat transfer between the cavity, mold, and cooling channels is computed. These results provide temperatures that vary both in location and in time. These Cool simulation results override any values you enter for Mold Temperature and Mold Temperature Profile.

Edit/Show Profile Select to define the mold temperature profile during the injection process. Enter the values of mold temperature versus time (in seconds or in percentage values of the total process time).