Many defects in injection-molded parts are caused by improper screw designs. Elimination of defects and optimization of the process can often be achieved via simple modifications to the screw. In a case study described in this presentation, a splay defect was caused by a screw with a low compression ratio, regions where resin can stagnate and degrade, and a limited melting capacity. Modifying the screw eliminated the defects, decreased the cycle time by 8%, and increased the plant capacity by 14%.