Accademia La Maison de la Danse Srld Italy

Precision injection molding of high performance components

requires primary error sources affected the molded component to be identified and isolated such that these errors can be

reduced if needed. To systematically isolate and quantify the contribution of misalignment, thermal variation and component

warpage to the accumulated error observed on the component, a methodology is presented and tested around an existing mold

which produced parts with high dimensional variability. The mold featured two concentric guide pillars on opposite sides of

the parting plane and rectangular centering block elements at three locations. Mold displacements at the parting plane were

measured through the incorporation of three eddy-current linear displacement sensors. Thermal error sensitivity was

investigated using FEM simulations such that the induced variability from thermal expansion and filling phase was identified

and quantified. Finally, molded component warpage was isolated and quantified, again by the means of FEM simulation. The

results were confirmed by using the mold on two injection molding machines to produce an array of parts whose key dimensions

were measured.