Study of Ejection Forces In The AIM™ Process

Abstract

The AIM™processhas been used to successfully produce short runs ofinjection moulded parts. One ofthe main drawbacks ofthe process is the tendency ofthe tools to be damaged during part ejection1 . At De Montfort University a successful AIMTM moulding cycle has been developed in which simple shapes from polypropylene are produced and the ejection forces required are measured. TWQ different ejection methods are used; one uses conventional ejector pins andthe other uses a conformal ejector pad. The tool surface roughness is measured before and after moulding to observe any changes caused by ejection. Results show that ejector pins require a lower ejection forcethan a conformal ejector pad and this may contribute to longer tool life forthe AIM™process. Possible reasonsfor the results are discussed along with recommendations for further work.