Mould cooling simulation for injection moulding using a fast boundary element method approach

Abstract

The existing cooling simulations for injection moulding are mostly based on the boundary element method (BEM). In this paper, a fast BEM approach for mould cooling analysis is developed. The actual problem is decoupled into a one-dimensional transient heat conduction problem within the thin part and a cycle-averaged steady state three-dimensional heat conduction problem of the mould. The BEM is formulated for the solution of the mould heat transfer problem. A dynamic allocation strategy of integral points is proposed when using the Gaussian integral formula to generate the BEM matrix. Considering that the full and unsymmetrical influence matrix of the BEM may lead to great storage space and solution time, this matrix is transformed into a sparse matrix by two methods: the direct rounding method or the combination method. This approximated sparsification approach can reduce the storage memory and solution time significantly. For validation, six typical cases with different element numbers are presented. The results show that the error of the direct rounding method is too large while that of the combination method is acceptable.

Potential of Rapid Tooling in Rapid Heat Cycle Molding: A Review

“…There are five main phases in the injection molding process which are melting, filling, packing, cooling, and demolding [ 80 , 81 , 82 ]. It is desirable to keep the filling and packing phases at a high temperature to promote polymer melt flow and enhance reproducibility of the molded product [ 80 , 83 , 84 ].…”

A novel method for predicting degrees of crystallinity in injection molding during packing stage

“…20 Injection molding is generally a three-stage process, comprising filling, packing, and cooling stages. 21 Mostly, in the filling stage, polymers are too hot to crystallize, while polymers are too cold to crystallize in the cooling stage. Hence, it is very important to predict polymers' crystallinity evolution information in the packing stage.…”

A multiple slicing approach to automatic generation of parting curves

“…After identifying the inner undercuts, the internal pins for the molding of the inner undercuts were then designed by extracting the related surfaces from the categorized surfaces. Zhou et al 30 developed a fast boundary element method (BEM) approach for mold cooling analysis. In their approach, a dynamic allocation strategy of integral points was applied to generate the BEM matrix based on the Gaussian integral formula.…”