Press speed (overmolding): XY Plot result

The Press speed (overmolding): XY Plot result shows the speed at which the press moved during of the overmolding step of the analysis.

This result is generated from a Thermoplastics injection-compression overmolding analysis, when you select injection-compression for the overmolding step.

Using this result

The compression phase of an injection compression analysis consists of two segments:

Press compression under speed control
During this time, the press follows the input specified for Press compression speed at incremental distances.
Press compression under force control
During this period, the press speed that is required to maintain the constant press force is calculated.
Note: The number of time steps plotted on the XY graph is determined by the input specified for the Number of regular results in Filling phase and Number of regular results in Packing phase options.

To specify the numbers of regular results to output,

  1. Click Process Settings (Home tab > Molding Process Setup panel > Process Settings).
  2. If necessary, click Next to access the Compression Settings page.
  3. Click Advanced options.
  4. Click Edit in the Solver parameters group, and select the Intermediate Output tab.

Things to look for

The objective is for the thickness of the molded part to be the same as the specified design thickness. This occurs when the press displacement result is equal, or as close as possible, to the press open distance.

Note: Design thickness + press open distance (input) - press displacement (result) = final molded part thickness.
If the final molded part thickness is too much larger than the design thickness, try adjusting one or more of the following process settings and re-run:
  • Increase the Press speed so that the press closes sooner.
  • Reduce the Press open distance.
  • Reduce the Press waiting time so that the press closes sooner, before too much material is injected into the cavity.
  • Increase the Press compression force so that the material is more compressed.
  • Keep the injection location open after packing so that extra material is squeezed out.
  • Reduce Velocity/pressure switchover by %volume so that less material is injected into the cavity.
  • Increase the Fill time, to reduce the flow rate.

An example of the relationship between the Injection-compression results and how to interpret them, is provided in the Press displacement result.

Parent topic: Overmolding results