A computational model for the cooling phase of injection moulding

This paper discusses the approaches and techniques used to build a realistic numerical model to analyse the cooling phase of the injection moulding process. The procedures employed to select an appropriate mesh and the boundary and initial conditions for the problem are discussed and justified. The final model is validated using direct comparisons with experimental results generated in an earlier study. The model is shown to be a useful tool for further studies aimed at optimising the cooling phase of the injection moulding process. Using the numerical model provides additional information relating to changes in conditions throughout the process, which otherwise could not be deduced or assessed experimentally. These results, and other benefits related to the use of the model, are also discussed in the paper. © 2007 Elsevier B.V. All rights reserved.

The rotational molding characteristics of metallocene polyethylene skin/foam structures

This article reports on the results of ongoing work in which the foaming characteristics of metallocene-catalyzed linear low density polyethylenes for rotational molding are investigated. Earlier publications related rheological and thermal parameters to the polymer structure and mechanical properties and found that metallocene polyethylene can be used in rotational foam molding to produce a foam that will perform as well as a Ziegler-Natta catalyzed foam. Through adjustments to molding conditions, the significant processing and physical material parameters, which optimize metallocene catalyzed linear low-density polyethylene foam structure, have been identified. This article details the optimum processing route for the production of two layer skin/foam parts using the drop box method. © SAGE Publications 2007.