Authors: C. Srirojpinyo, S-H Yoon, J. Lee, C. Sung, J.L. Mead and C.M.F. Barry
Affilation: University of Massachusetts Lowell, United States
Pages: 464 - 467
Keywords: nanoinjection molding, nanoscale features
Although micro parts and features are routinely molded, the performance of polymer melts is not well understood when the part wall thickness is less than 1 mm. In this study, the effects of molding conditions and material properties were determined for the replication of nanoscale features via injection molding. The nanoscale features were part of a thin insert incorporated into the mold. Polypropylene, polystyrene, polycarbonate, and polymethylmethacrylate (PMMA) were examined using a two-level design of experiments designed to investigate the effects of melt temperature, mold temperature, injection velocity, and packing pressure on depth ratio and surface quality. Atomic force microscopy (AFM) was employed to measure the molded parts. Polypropylene provides the best replication with broad process window while polycarbonate is the best replicated of amorphous materials with narrower process window. As expected, replication is material dependent and better achieved with higher melt temperature and mold temperature.