Variable Offset Computation Space for Automatic Cooling Dimensioning

Abstract

The injection mold is one of the most important elements for the part precision of this important mass production process. The thermal mold design is realized by cooling channels around the cavity and poses as a decisive factor for the part quality. Thus, the objective but specific design of the cooling channel layout is crucial for a reproducible part with high-dimensional accuracy in production. Consequently, knowledge-based and automated methods are used to create the optimal heat management in the mold. One of these methods is the inverse thermal mold design, which uses a specific calculation space. The geometric boundary conditions of the optimization algorithm influence the resulting thermal balance within the mold. As the calculation area in the form of an offset around the molded part is one of these boundary conditions, its influence on the optimization result is determined. The thermal optimizations show a dependency on different offset shapes due to the offset thickness and coalescence of concave geometries. An algorithm is developed to generate an offset for this thermal mold design methodology considering the identified influences. Hence, a reproducible and adaptive offset is generated automatically for a complex geometry, and the quality function result improves by 43% in this example.

Methodology of a thermal injection mold design with locally applied heating coatings on the cavity wall

“…In the inner edges, it is the opposite effect. The outer offset is generated with a constant 10 mm Minkowski offset according to the algorithm developed in previous works [29]. Then an optimization of the thermal mold balance is conducted.…”

“…In analogy to the existing design routine, the part geometry is the starting point. Similarly, the offset for the following thermal optimization step is created according to previous works [29]. Parallel to this step, the starting and boundary conditions need to be defined.…”