Microcellular technology has been enormously developing and applied in many foaming processes for many industrial polymers manufacturing, since the microcellular batch processing technology has brought out by Dr. Nam Suh and co-workers at MIT in the early 1980s . The microcellular application used in reciprocating screw injection molding machine was built by Trexel and Engel in 1998 . Despite the microcellular technology has been developing for many decades and widely used in today’s plastic product manufacturing, the reliable computer aided engineering application is not well developed due to limited understanding of complex foaming mechanism. Venerus  reviewed numerous diffusion-controlled modeling studies of polymer foaming and showed the diffusion-induced bubble growth in viscoelastic liquids numerically having good agreement with experimental data. Taki  studied the effects of pressure release rate on bubble density and sizes. Recently, the previous developed models of cell foaming have been couple with 3D flow motion technology for microcellular injection molding. However, the dynamic features of bubble growth and the integration from bubble growth mechanism to the final injected parts are not fully developed. In this chapter, we are going to describe about the numerical development in microcellular injection molding. Furthermore, the dynamic features of bubble growth, including bubble size and bubble density are validated with the experimental data done by Turng and co-workers . Moreover, this advanced CAE technology is applied in some case to realize how and why microcellular process can benefit in details.
Polymeric Foams; Innovations in Processes, Technologies, and Products, Page345-360