Interface development and encapsulation in simultaneous coinjection molding of disk. II. Two‐dimensional simulation and experiment

Abstract

AbstractTwo‐dimensional simulation and experimental studies of flow‐rate‐controlled coinjection molding were carried out. Skin polymer was injected first, and then both skin and core polymers were injected simultaneously into a center‐gated disk cavity through a two‐channel nozzle to obtain an encapsulated sandwich structure. The physical modeling and simulation developed, reported in Part I of this series, were based on the Hele–Shaw approximation and the kinematics of the interface to describe the multilayer flow, and the interface development was used to predict the skin/core distribution in the moldings. The effects of rheological properties and processing conditions on the material distribution, penetration behavior, and breakthrough phenomena were investigated. The predicted and measured results were found to be in a good agreement. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2310–2318, 2003