Now showing 1 - 2 of 2
  • Publication
    Replication of micro/nano-scale features by micro injection molding with a bulk metallic glass mold insert
    (IOP Publishing, 2012-05-17) ; ; ;
    The development of MEMS and Microsystems needs a reliable mass production process to fabricate micro components with micro/nano scale features. In our study, we used the micro injection molding process to replicate micro/nano scale channels and ridges from a Bulk Metallic Glass (BMG) cavity insert. High density polyethylene (HDPE) was used as the molding material and Design of Experiment (DOE) was adopted to systematically and statistically investigate the relationship between machine parameters, real process conditions and replication quality. The peak cavity pressure and temperature were selected as process characteristic values to describe the real process conditions that material experienced during the filling process. The experiments revealed that the replication of ridges, including feature edge, profile and filling height, was sensitive to the flow direction; cavity pressure and temperature both increased with holding pressure and mold temperature; replication quality can be improved by increasing cavity pressure and temperature within a certain range. The replication quality of micro/nano features is tightly related to the thermomechanical history of material experienced during the molding process. In addition, the longevity and roughness of the BMG insert was also evaluated based on the number of injection molding cycles.
    Scopus© Citations 85  1091
  • Publication
    Micro injection molding: characterisation of cavity filling process
    (Society of Plastics Engineering, 2011) ; ;
    Based on reciprocating micro injection molding machine, this paper characterizes the influence of machine process parameters and its transition response from velocity control to pressure control (V-P transition) on the micro cavity filling process. The method of Design of Experiment was employed to systematically and statistically investigate the effect of machine parameters on actual cavity filling process, which was described by the defined process characteristic values (PCVs). The statistical analysis of the experiments indicated that injection speed was dominated factor affecting all PCVs in cavity filling process. It was also found that the machine V-P transition have significant effects on cavity filling.
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