This research designed necessary orthogonal array and than determine factors that influence the quality of shuttle protector production process at Mitra Utama. The research was done for horizontal injection molding machine and only considered machine and material factors. Using Taguchi technique, L934 orthogonal array was chose as the experiment design and time as the measured response. By performing One-sample Kolmogorov-Smirnov test, Bertlett test, analysis of variance and pooling up analysis, it was found that the operating cylinder pressure and screw conveyor speed significantly influence the quality of shuttle protector protector production process at Mitra Utama. The best levels are 80 bars for the operating cylinder pressure and 110 rpm for the screw conveyor speed.