Development of shrinkage model of micro structured vitreous carbon mold for glass molding

Abstract

Carbonization of replicated furan precursors has been proposed as a low-cost large-area method for fabricating microstructured vitreous carbon (VC) molds to glass micromolding. During the carbonization of furan precursors, large anisotropic shrinkage occurs inherently owing to thermal decomposition of the material, and this anisotropic shrinkage should be compensated to obtain the designed profiles of microcavities on the VC mold. In this study, a linear gradual shrinkage ratio model (LGSRM) was developed to predict the anisotropic shrinkage characteristics associated with the fabrication of microstructured VC molds. To verify the shrinkage model, the shape change of the VC mold according to the LGSRM was simulated with ANSYS and compared with the experimental results. To determine the coefficients of LGSRM, a finite element analysis code, in which a gradual shrinkage ratio can be assigned to each individual mesh, was developed, and the coefficients of LGSRM were selected to minimize the errors between the simulated and measured geometrical properties of the VC mold.