Injection Molding of Plastics from Agricultural Materials

OBJECTIVE DOE Chicago Operations %ice The objective of this research was to conduct a systematic study to relate injection molding parameters to properties of blends of starch and synthetic polymer. Blends of normal (25 % amylose) and high amylose (50 and 70% amylose) corn starch (containing between 60 and 70 % of the mixture by weight) and synthetic polymer were used in this research. Two different classes of synthetic polymer were be used. The first is a fully biodegradable synthetic polyester while the second is a non-degradable polyolefin. The blends were made in an extruder. Specifically, the objective included: i) determine the rheological properties of the blends. ii) study the effect of injection molding parameters on weld line strength, iii) evaluate the effect of molding parameters on the tensile, flexural and impact strength, residual stresses. crystallinity, density variation, morphology, and shrinkage of starchhynthetic polymer blends, and iv) test the degradability of the blends. From this study we wished to develop a thorough understanding of the injection molding process and gain significant insight into designing molds and aiding in developing products cheaply and efficiently.