Influence of Runner Angles on Balanced Filling for Multicavity Moulding

Abstract

This paper deals with the influence of runner angles on the balanced filling of a three-cavity mould during injection moulding. The main goal of the study is to understand the influence of the angles between the runners and the balanced filling of the three individual parts. Balanced filling leads to better visual and mechanical properties of the final product. Different mould flow simulations with the same processing parameters (material, temperature, pressure and time) were performed to observe the influence of the runner angle. Polypropylene was used as the reference material in this paper. A simple cylindrical part was considered here. In essence, it seems to be a very simple situation, however before running the mould flow simulations there was no general notion of the results and their justification. The paper also raises the possibility for modifying filling behaviour by changing the runner angles and evidence that the configuration with 90 degrees between each runner is the most suitable for achieving the filling of the three parts at the same time.

Optimization of Runner Balance for a Family Product of Injection Molding Process

“…Wang and Sun [6] analyzed the runner imbalance in the top cover cavity and brought the product box with the Moldflow Insight 5.0 analysis, the results showed that through optimization, the imbalance of plastic fluid flow in the cavity decreased from 28.6% to 0.7%, the pressure imbalance rate injection can be decreased from 42.0% to 4.2%, and the pressure distribution in the cavity is more uniform throughout the injection-process. Raz et al, [7] modified the runner angle and balanced the injection of plastic material in the three products, the results showed that the 90º angle configuration for the runner was proven to be able to uniform the filling time of the plastic material to the three products. Azaman et al, [8] examined the process of filling plastic material in the cavity for analysis of residual stress and warpage in both types of thin parts of the cavity with Moldflow software.…”