Material Properties (Polymer, Mold, and Coolant Domains)

Depending on the material you apply to a cavity, insert, mold, or cooling channel domain, the complete list of material properties appears in the selected material's dialog box.

Domain Material Parameters Definition
Polymer Melt Temperature Defines the material manufacturer’s recommended temperature of the polymer as it exits the molding machine through the nozzle and enters the mold. Minimum and maximum values define the manufacturer’s allowable range.
Polymer Mold Temperature Defines the material manufacturer’s recommended temperature of the mold during injection. Minimum and maximum values define the manufacturer’s allowable range.
Polymer Ejection Temperature Defines the temperature of the part when it has cooled down and is ready for ejection.
Polymer Transition Temperature Defines the temperature at which a polymer changes from melted to solid state. For semicrystalline materials, this is a precise temperature. For amorphous materials, the transition occurs gradually over a range of temperatures, but is given as a single value.
Polymer, and Coolant Viscosity Defines a measure of a melted polymer's resistance to a flow. Highly viscous fluids, like peanut butter, resist a flow much more than low viscosity fluids like water. Most polymers are non-Newtonian, which means their viscosity is dependent on the shear rate they experience. Polymers solidify as they cool, so their viscosity also depends on temperature.
Polymer Pressure-dependent Viscosity

The viscosity of some polymers increases with pressure (a phenomenon known as pressure-dependent viscosity). Generally, this characteristic is more prevalent with amorphous polymers than with semicrystalline polymers. Polymers with pressure-dependent viscosity are listed in the Polymer Materials database with an information icon.

It is particularly important to account for pressure-dependent viscosity when parts contain long flow lengths or very thin walls, or for cases where high injection pressures are required. Consider the following guidelines:
  • Refine the mesh sufficiently through the part thickness to capture local variations in temperature and pressure throughout the molding cycle.

  • Set the Injection Pressure Limit by taking into account the actual limit of the injection molding machine and the injection location of your model.

  • Set realistic values for the Filling Time, Flow Rate Profile, and Pack properties, which might have significant impact on the results.

  • Accept the default values for the mold-melt heat transfer coefficients, and adjust them to their actual values, if they are available.
Polymer, and Coolant PVT(pressure, volume, temperature) Defines the relationship between pressure, volume, and temperature parameters that evaluate how much a polymer shrinks as it cools from melted to solid state during the injection molding process.
Polymer, and Mold Solid Density Defines the mass-per-unit volume of a material in its solid state.
Polymer, Mold, and Coolant. Specific Heat Defines the amount of energy required to heat one kilogram of a material by one Kelvin.
Polymer, Mold, and Coolant Thermal Conductivity Defines a measure of how easily thermal energy can transfer through a material.
Polymer, Mold Elastic Modulus Defines a measure of a material's resistance to deform elastically under stress application. More specifically, the ratio of tensile stress to tensile strain (also known as Young's modulus).
Polymer, Mold Poisson's ratio Defines the ratio of transverse contraction strain to longitudinal extension strain in the direction of the stretching force.
Polymer, Mold Thermal Expansion Coefficient Defines a measure of how a material expands and contracts because of changes in temperature.
Polymer Shear Relaxation Modulus Defines a measure of how a material relieves stress over time when subjected to constant strain.
Polymer Curing Model Describes the curing process for a thermoset material.
Polymer No-Flow Temperature Defines the temperature at which a polymer no longer flows.
Polymer Melt Flow Rate Defines a measure of the ease of flow of a melted polymer.
Polymer % Fiber Defines the percentage of fiber filler by weight.
Polymer Max Shear Rate Defines the material manufacturer’s maximum allowable shear rate.
Polymer Max Shear Stress Defines the material manufacturer’s maximum allowable shear stress.
Polymer Stress Optical Coefficient Defines a measure of the amount of birefringence because of residual stress in a transparent polymer.

Birefringence is the optical property of a material having a refractive index that depends on the polarization and propagation direction of light.

Polymer Leonov Parameters Defines the parameters of the Leonov Viscoelastic Model used to predict birefringence. Viscoelastic materials exhibit both viscous and elastic behavior under stress. Material deformation is temporary when the stress is removed quickly, but permanent when the stress is sustained.
Polymer WLF Parameters Defines the Willams-Landel-Ferry (WLF)) equation coefficients for the Leonov Viscoelastic Model.
The WLF equation is:

where T is the temperature, Tris a reference temperature, and C1 and C2 are empirical constants.

Polymer, and Mold Shear Modulus Defines the in-plane ratio of shear stress to shear strain.

If the Shear Modulus (G12) of a material is not available, an approximate value for G12 is considered in the analysis. The approximate value is calculated based on the methods published in “Introduction to Composite Materials Design,” Second Edition, by E. J. Barbero.

Polymer Crystallization Kinetics

Defines a measure of the crystallization process of a semicrystalline polymer that occurs between its melting point and glass transition temperature.

Polymer Juncture Loss Coefficients Defines a measure of the hydraulic loss experienced when a polymer flows through a significant change in cross-sectional area, such as those common to a runner system.
Polymer Data Source and Information Indicates the source of the material data and any additional grade-specific information.

Manufacturer name; Generic PVT Data

Shows the manufacturer who provided the grade-specific material data. Indicates that the pressure, volume, and temperature data are generic, while the rest of the data are grade-specific and are provided by the material manufacturer.

Manufacturer name; *to be phased out

Indicates that the material manufacturer is planning to phase out the specific material grade.