Factor to predict the weld line strength
27. Sep 2023

Factor to predict the weld line strength


Weld lines are unavoidable when the melt flows around an obstacle. They represent a mechanical weak point of the component, which should be considered when designing the component. Therefore, we are pleased to present the new function in Moldex3D 2023 which predicts the weld line factor.

Weld lines occur when two melt/flow fronts meet during the filling process. With sufficient molecular energy and movement time in the weld line region, a high weld line factor is encountered.
Taking temperature into account, it is now possible to output the weld line factor. The weld line factor is defined as the ratio of the stresses that the material can withstand before the weld line fails, compared to the ground state. 100% means that the polymer chains are completely mixed. In this case, the weld line strength would be equal to that of the base material without the weld line. The calculation in Moldex3D is available for the injection molding process. The model must be meshed in Solid or e-Design for this purpose and the result is not currently available in Quick Flow and Process Simulation. The material model of viscoelasticity should be White-Metzner or Oldroyd-B Model and the viscosity model should be Modified Cross Model or Herschel Bulkley Cross Model.

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