Two Component Injection Molding of Phase Separating Blends

Abstract

A partially miscible polymer PMMA/SAN blend is used in two component injection molding to produce a sandwich structure with a heterogeneous skin layer. Two different strategies are explored to obtain the desired structure either via sequential injection molding or via the use of the fountain flow. Both cases are studied with scanning electron microscopy to visualize the structure in the skin layer. In addition, numerical modelling examples are presented to improve understanding of the morphologies that have been created with injection molding.

Experimental and computational study on structure development of PMMA/SAN blends

“…In our study, we use macroscopic diffuseinterface modeling based on the Cahn-Hilliard theory, in which the thermodynamics and hydrodynamics are coupled through the momentum equation. The advantage of this approach is that the thermodynamic and hydrodynamic parameters for the model can be derived from experiments (Keestra et al, 2006).…”