Experimental design to enhance the surface appearance, the internal structure, and the shear stresses of injected and metallized polycarbonate/acrylonitrile-butadiene-styrene parts

Polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) possess thermal and mechanical properties, which make them materials of choice for automotive components. These properties have presented PC/ABS as an eligible replacement for metals in automotive industry. The aim of this study was to explore a new approach to determine the optimum conditions for obtaining quality and shear stresses of the injected and metalized PC/ABS parts. For this purpose, the following six injection-molding parameters such as material temperature (T-ma), injection pressure (P-inj), holding pressure (P-h), mold temperature (T-mo), holding time (t(h)), and cooling time (t(c)) were considered at four different values. The effect of the injection parameters studied has been analyzed through the quality and the shear stresses values of the injected and metallized PC/ABS specimens. Optical microscopic and confocal laser scanning microscope (CLSM) results demonstrate that the occurrence of some defects such as weld line, blister, poor adhesion, metal residue, sand scratch. Moreover, scanning electron microscope (SEM) findings show the presence of core defects and solidified pellets. Shear stresses vary between 3.78 and 5.8 MPa for the injected specimens and 4.5 and 6.4 MPa for the metallized specimens. The optimum injection parameter combinations were conditioned by producing flawless injected and metallized PC/ABS parts having a significant shear stress value. Thus, the optimum combinations consists of: a T-ma of 260 degrees C, a P-inj ranging between 30 and 50 bar, a P-h ranging between 20 and 25 bar, a T-mo of 40 degrees C, a t(h) ranging between 8 and 14 sec. and a t(c) of 25 sec. These findings may have interesting applications in automotive part industry. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48384.