DOINA DIMONIE, CELINA DAMIAN, ROXANA TRUSCA, MARIA RAPA SOME ASPECTS CONDITIONING THE ACHIEVING OF FILAMENTS FOR 3D PRINTING FROM PHYSICAL MODIFIED CORN STARCH It was found that the obtaining of quality 3D printing filaments, without defects and natural color, from corn starch physical modified with PVOH, depends also on the melting behavior at compounding, both of starch and of PVOH, and on the controlling of the process sensitivity of the new compounds. A comparable melting behavior was possible by compounding the two polymers as powders with similar small sized particle. The controlling of the process sensitivity was achievable, mainly, by diminishing the melt resistance to flow, via formulation with a flow agent. The selected compounds which had controlled miscibility, few defects and natural color were shaped, with good results, as filaments with silky and smooth surface. These filaments were compatible with 3D printing because proved to have the ovality and the diameter tolerance in the accepted limits in the fields.
Keywords: Compounds, thermoplastic starch, 3D printing, miscibility, process sensitivity, melt degradation