TY - JOUR
T1 - Effects of polymer melt compressibility on mold filling in micro-injection molding
AU - Nguyen, Q. M.P.
AU - Chen, X.
AU - Lam, Y. C.
AU - Yue, C. Y.
N1 - Publication details (e.g. title, author(s), publication statuses and dates) are captured on an “AS IS” and “AS AVAILABLE” basis at the time of record harvesting from the data source. Suggestions for further amendments or supplementary information can be sent to [email protected].
PY - 2011/9
Y1 - 2011/9
N2 - In conventional injection molding, the molten polymer in the filling stage is generally assumed to be incompressible. However, this assumption may not be valid in micro-injection molding, since high injection pressure is normally required to avoid short shots. This paper presents both numerical and experimental investigations on the effects of polymer melt compressibility on mold filling into a micro-thickness impression. The study was conducted on six different part thicknesses ranging from 920 to 370 νm. A high-flow COC TOPAS 5013L-10 polymer was chosen as the TOPAS family has recently attracted significant interest for its use in microfluidic applications. A combined finite element/finite difference/control volume approach was adopted to simulate the compressible flow. The shear viscosity of a polymer melt was characterized by the Cross-WLF model, while the melt compressibility was modeled with a double-domain Tait equation. The results obtained indicated that the compressibility of the polymer melt has significant effects on impression pressure and density distribution in the fully filled part with thickness smaller than 620 νm and that the effects become more pronounced with a decrease in part thickness. © 2011 IOP Publishing Ltd.
AB - In conventional injection molding, the molten polymer in the filling stage is generally assumed to be incompressible. However, this assumption may not be valid in micro-injection molding, since high injection pressure is normally required to avoid short shots. This paper presents both numerical and experimental investigations on the effects of polymer melt compressibility on mold filling into a micro-thickness impression. The study was conducted on six different part thicknesses ranging from 920 to 370 νm. A high-flow COC TOPAS 5013L-10 polymer was chosen as the TOPAS family has recently attracted significant interest for its use in microfluidic applications. A combined finite element/finite difference/control volume approach was adopted to simulate the compressible flow. The shear viscosity of a polymer melt was characterized by the Cross-WLF model, while the melt compressibility was modeled with a double-domain Tait equation. The results obtained indicated that the compressibility of the polymer melt has significant effects on impression pressure and density distribution in the fully filled part with thickness smaller than 620 νm and that the effects become more pronounced with a decrease in part thickness. © 2011 IOP Publishing Ltd.
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U2 - 10.1088/0960-1317/21/9/095019
DO - 10.1088/0960-1317/21/9/095019
M3 - RGC 21 - Publication in refereed journal
SN - 0960-1317
VL - 21
JO - Journal of Micromechanics and Microengineering
JF - Journal of Micromechanics and Microengineering
IS - 9
M1 - 095019
ER -