Effects of Mold Cavity Temperature on Surface Quality and Mechanical Properties of Nanoparticle-Filled Polymer in Rapid Heat Cycle Molding

摘要

Acrylonitrile-butadiene-styrene (ABS)/poly methyl methacrylate (PMMA) and ABS/PMMAano-CaCO3 composites were prepared in a corotating twin screw extruder. Single-gate and double-gate samples were molded based on a rapid heat cycle molding (RHCM) system. Effects of mold cavity temperature on surface quality and mechanical properties of single-gate and double-gate samples in RHCM process were conducted. The results showed that surface quality of plastic parts can be improved significantly by increasing mold cavity temperature. Nano-CaCO3 particles on the surface of plastic parts can be eliminated by using high mold cavity temperature. The roughness and gloss of two kinds of plastic parts (ABS/PMMA and ABS/PMMAano-CaCO3) stabilized at the same level when the mold cavity temperature is above glass transition temperature of resin material. Weld line can be eliminated in RHCM process during high mold cavity temperature. The tensile strength of both ABS/PMMA and ABS/PMMAano-CaCO3 exhibited decreasing trend with the increase of mold cavity temperature. Reduction of internal stress gave rise to the increase of Izod impact strength of ABS/PMMA for both sing-gate and double-gate samples. However, influence regularity of mold cavity temperature on Izod impact strength of ABS/PMMAano-CaCO3 is depended on the number of gates. For all the samples in this study, too high of mold cavity temperature (higher than 125 degrees C) deprave Izod impact strength of plastic parts. Both ABS/PMMA and ABS/PMMAano-CaCO3 are not susceptible to weld line. When the mold surface temperature is approximately equal to glass transition temperature of resin material, all the samples are found to give the best combination of properties. (C) 2014 Wiley Periodicals, Inc.