Viscosity takes an important role in filling simulation in injection molding. This paper presents a computational approach to estimate the 7 parameters of Cross-WLF viscosity model based on nonlinear fitting technology. The numerical strategy is line search. Line search Newton Method is employed here since the Newton direction is the most efficient one. Test case shows its results are of high accuracy and the RMS error between fitting and experimental data is less than 10-5.

Cooling analysis with the boundary element method (BEM) forms full-matrix equations in injection molding. Computers have no ability to handle it when the element number is more than its acceptance. This paper adopts the elements incorporation method. It changes the original model from one large matrix equation to one small union matrix equation and several small block matrix equations. In this way, the calculation time is shortened considerably and the treatable number of element in cooling analysis is enhanced dramatically. In-mold labeling processing, which adds a label on part surface in the mold is a new technology, and it is becoming more and more popular. It affords the mold designer far greater latitude in the design of graphics, part shape, and the use of multiple molded components in a single molded unit. Its simulation is a new task in computer aided engineering (CAE). This paper is based on the feature that the cavity surface is always meshed into planar triangular elements, Supposing that the label and part are two plates with perfect contact, establishes a one dimensional unsteady heat transfer model under the first dissymmetry boundary for each element. Using this heat transfer model, the cooling analysis model of in-mold labeling is established.

This paper proposes a numerical model of cooling analysis of an injection mold that has an embedded insert. The Boundary Element Method (BEM) is employed because of its popular usage in this area. The key problem in model building is how to involve the independent surface between mold and insert into the BEM equations and how to give the natural boundary conditions on it. This problem is solved by using coupling BEM which provides an attractive alternative in that the natural boundary condition is shifted to the surface between part and mold. So, instead of using the finite differentiation method, the boundary condition can be determined analytically. This is useful in improving the accuracy of cooling analysis.