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Viscoelasticity

Plastics (Polymeric) fluids are often called viscoelastic fluids because they have both viscous and elastic properties. The viscoelastic effect is dependent on different temperatures and shear-rates. At filling stage, flow field varies severely, and viscous property of polymer dominates flow behavior.

Moldex3D Viscoelasticity can predict the frozen flow-induced stress near the mold surface due to fast solidification caused by high cooling rates during filling. As solidification keeps developing during packing, the high temperature remained by solidification within the mold helps to release the stress. However, flow-induced stress may develop in the central area near the gate due to additional shear flow during packing. Different cooling efficiencies at different cooling processes would also affect the stresses relaxation. Above conditions during injection molding process can all be well caught and predicted by Moldex3D Viscoelasticity.

Furthermore, Moldex3D Viscoelasticity can describe the anisotropic molecular orientation by the maximum principal stress (maximum normal stress) of flow-induced residual stress. Molecular orientation information, maximum normal stress and maximum shear stress also help users to find out whether the final product is acceptable and to further modify the mold design and process condition. The results obtained form Viscoelasticity can also be applied to predict the optical properties and be taken into account in the warpage analysis.

Capabilities

Moldex3D Viscoelasticity allows you to

Predict the flow-induced residual stress and know the variation of each stress variable during injection molding process.
Predict the final product’s maximum normal stress and maximum shear stress in each point of the space.
Know the information about the solidification and stress relaxation during processing.
Know the information about the molecular orientation.

Features

Apply constitutive equations form visoelastic theory to predict flow-induced stress.
Integrate filling, packing, cooling and warpage to get the whole stress distribution during processing.
Know the anisotropic properties in the space, which can be extended to predict optical properties, i.e. birefringence.