Design of Sprue Bush for a Plastic Injection Mould: A Machine Perspective

Design methodology and criteria to configure sprue bush for enhancing functionality is systematically compiled from plastic injection moulding machine perspective. Sprue conduit’s sensitivity to moulding objectives are quantitatively ghettoised as expansion ratio on the basis of ubiquitous empirical relationships. This generic, simple, inexpensive preventive criterion enables sprue bush conduit geometry design to exemplifying the melt injection specifically for a particular machine. Continuous Sensitivity Equation Method (CSEM) was adopted to sensitise sprue conduit expansion over infinite dimensional range exclusively for injection rate, maximum injection pressure and barrel size. Inferred results were exponential in nature with injection rate having direct proportionality, while maximum injection pressure and barrel size had inverse proportionality to conduit expansion off parting plane. Off them injection rate was found to be relatively more influential than injection pressure and barrel size. Keywords—Sprue bush conduit, Injection rate, Maximum injection pressure, Barrel size