Impact Properties and Microhardness of Double-Gated Glass-Reinforced Polypropylene Injection Moldings

MARTINEZ GAMBA, M.; ANTO´ NIO SERGIO POUZADA,; P.M. FRONTINI

POLYMER ENGINEERING AND SCIENCE

JOHN WILEY & SONS INC

Año: 2009 vol. 49 p. 1688 - 1695

0032-3888

Injection moldings with weld lines were produced inglass reinforced polypropylene grades differing in fillercontent using a two-gated hot runner injection mold.The skin-core microstructure developed during injectionmolding was qualitatively analyzed by means ofoptical and scanning electronic microscopy techniques.The load bearing capacity of the moldings wasassessed by uniaxial tensile-impact and biaxial instrumentedfalling dart impact tests. Microhardness wasalso used to ascertain the possibility of using it as asimple nondestructive technique for characterizingglass fiber-reinforced injection moldings. The propertieswere monitored at various points to evaluate theirvariation at the bulk and the knit region. The biaxialimpact test highlights the 10-fold reduction of theimpact strength caused by the weld line. 2009, vol. 49, no9, pp. 1688-1695