2.3.2. Polymers

Purpose

In this section, you define the material properties and link them to the geometry. Without a correct assignment, the solver cannot execute the simulation.

Polymers Icon Access: Access this window by clicking the Polymers icon in the main toolbar or go to Data -> Plastic Part Data -> Polymers.

Pre-loaded Polymer Types

The software includes 9 default polymer types commonly used in rotational moulding, plus a User Material with empty properties for custom definitions:

  • MDPE Medium-Density Polyethylene
  • LDPE Low-Density Polyethylene
  • HDPE High-Density Polyethylene
  • LLDPE Linear Low-Density Polyethylene
  • XLPE Cross-Linked Polyethylene
  • PP Polypropylene
  • NY Polyamide PA12 / Nylon
  • EVA Ethylene Vinyl Acetate
  • PC Polycarbonate

Material Management and Editing

  • Naming: You can edit the "Name" field to identify your specific material (e.g., "PEAD - Supplier X"), but the base polymer type selection cannot be changed.
  • Editing Properties: All properties in the three tabs are editable. You should adjust them to match your material's technical Data Sheet (TDS).
  • Restoring Values: Use the Restore Values button to revert to defaults before saving. Once changes are saved, automatic restoration is not possible; values must be re-entered manually.
Out-of-Range Warning: If a value is entered that is outside the physical range expected for that specific polymer type, the program will notify you during the validation process before starting the simulation.
User Material: This profile allows you to enter any value without range restrictions. It is useful for experimental materials, but use with caution: incoherent values will lead to poor simulation results.

Properties Breakdown

The properties are organized into three tabs. Ensure these values match your polymer's documentation:

1. Physical & Mechanical
Physical and Mechanical Tab Properties: Density, Melt Index, Flexural Modulus, Tensile Strength at Yield.
2. Thermal
Thermal Tab Properties: Melt Temperature, HDT, Conductivity (K), Expansion Coefficient.
3. Others
Others Tab Properties: Shrinkage, Granulometry (Mesh), and Comments.

Note: Beyond these visible properties, the program internally utilizes viscosity and phase-change curves specific to each polymer type to ensure physical calculation rigor.

Assignment Methods (Assign / Unassign)

Configuring the material is only the first part; it must be assigned to the part or mesh. The method depends on your View Mode:

A. Part Mode (Volume Assignment):
  1. Click Assign.
  2. Click on the part in the main workspace. The material is assigned to the entire volume.
  3. If different materials are assigned sequentially, the last one assigned will prevail.
B. Mesh Mode (Element Assignment):
  1. Click Assign.
  2. Select at least one mesh element. This assigns the material to the entire meshed body.
  3. If multiple materials are assigned to the same mesh body, the one linked to the lowest Element ID will prevail.

Verification: Check the Data Tree. When the Polymers item shows a green checkmark, the assigned material name will appear next to it.

Unassigning: Use the Unassign button. Select the part (in Part Mode) or the mesh (in Mesh Mode) to remove the current assignment.