Criticality of appreciating non-newtonianivity in plastic injection mould conduit design

Abstract

The prime intention of this research was to emphasise criticality of Non-Newtonian injectant behaviour to design ideal runner conduits for plastic injection moulds. Power-law constitutive relation was representatively adopted so shear thinning index could contrast, both Non-Newtonian and Newtonian behaviours together. An a priori analytical solution was developed from Power-law constitutive relation analogous to celebrated Hagen-Poiseuille solution for tubular runner conduits. This solution leveraged the computational intelligence advantage to enable a design criteria for perfect injection into impression gap synchronising injector capacity, injectant character as well as desired moulding features. The proposed design criteria readily adapts in practise including extremely complicated feed system configurations. Further to incorporate comprehensiveness, continuous sensitivity method was also adopted to discriminate cruciality over an infinite dimension scale, which lead insight into various important aspects that would certainly form a basis to diagnose filling issues reasoning several defects. For representation a sample set of runners from realistic, productive moulds that were initially designed with Newtonian hypothesis and later during trails heuristically optimised were compared, interestingly, they were statistically skewed towards runner sizes that were directly determined appreciating Non-Newtonian injection behaviour. Therefore, it was concluded that Non-Newtonian injection behaviour should have significant prominence in injection mould design criteria. 2015 Begell House, Inc.