Study PropertyManager

You use the Study PropertyManager to create a new Plastics study or edit an existing one.

To open the Study PropertyManager:

  • Click New Study (Plastics CommandManager).
Use the Study PropertyManager to:
  • Assign a name for the study.
  • Select the injection process type (single polymer material versus multimaterial process).
  • For multi-material overmolding, specify the number of injection units (2–6).
  • Select the analysis procedure (solid or shell).

Name

Enter a name for the new study, or leave the default study name.

Injection Process

Select one option:
Single Material Only a single polymer material is considered in the injection process. Single Material is supported by both solid and shell analysis procedures.
Bi-injection

Two different polymer materials are injected (possibly at the same time) at different locations, with each injection process being independently controlled. The materials meet, and form a weld line within the cavity.

Only the solid analysis procedure supports Bi-injection. A single cavity and two materials are allowed.
Co-injection
Two different polymer materials are injected sequentially at the same location (sandwich molding). Common reasons for using co-injection are:
  • To use a cheaper fill material for the hidden core of a product.
  • To combine properties of different polymers, such as color, feel, or mechanical properties.
Co-injection is supported by the solid analysis procedure only. A single cavity and two materials are allowed.
Gas-assist

A pressurized inert gas (typically nitrogen) is injected into a partially or nearly-filled cavity. The gas displaces the molten plastic material in thicker regions of the part to complete the filling and to pack the cavity. The resulting hollow part offers several benefits: less plastic material, reduced part weight, lower cycle time, reduced warpage and distortion, and improved part appearance.

Gas-assist is supported by the solid analysis procedure only. A single cavity and two injection units with different materials are allowed.
Water-assist Water is injected into the melted polymer stream to create a hollow part.

Water-assist is supported by the solid analysis procedure only. A single cavity and two injection units with different materials are allowed.
Multi Material Overmolding Two or more different polymer materials are injected within the same cycle. Separate injection nozzles introduce materials sequentially into the cavities. This is achieved by using a special mold that rotates between cycles. You can specify as many as six injection units, each with a different material.

This process is also called multi-shot injection.
The table summarizes the number of materials and cavities allowed for each injection process type.
Injection Process Number of Injection Units (Materials) Number of Cavities
Single Material 1 Any
Bi-injection 2 1
Co-injection 2 1
Gas-assist 2 1
Water-assist 2 1
Multi Material Overmolding 2 to 6 Any

Analysis Procedure

Solid Requires a solid mesh for the domain selections. The solid analysis procedure supports all injection processes and domains of all types (cavity, cooling channel, runner body, mold insert, part insert, and mold body). The solid analysis procedure is generally the most accurate, provided that the mesh resolution is adequate across the cavity.
The processing time to accurately model thin parts with the solid procedure can be high.
Shell Requires a shell mesh for the cavity domain. The shell analysis procedure can only support a single domain of the Cavity type. The shell procedure cannot accurately model grid-like or strip-like configurations, or parts with step-changes in thickness.
The modeling assumptions (Poiseuille flow for runners and Hele-Shaw flow for cavities) account for possible differences in results between shell and solid analysis procedures.
Use sketches to model runners when you use the shell analysis procedure.
You can create only one Plastics study per configuration.