For this volume, experts in rheology and polymer processing present fundamental and applied information on the rheological properties of polymers, in particular those relevant to processing, contributing to the physical understanding and the mathematical modelling of polymer processing sequences. Basic concepts of non-Newtonian fluid mechanics, micro-rheological modelling and constitutive modelling are reviewed, and rheological measurements are described. Topics with practical relevance are debated, such as linear viscoelasticity, converging and diverging flows, and the rheology of multiphase systems. Approximation methods are discussed for the computer modelling of polymer melt flow. Subsequently, polymer processing technologies are studied from both simulation and engineering perspectives. Mixing, crystallization and reactive processing aspects are also included. This book aims to provide an integrated and complete view of polymer processing and rheology, and is intended for institutions and individuals engaged in the characterization, testing, compounding, modification and processing of polymeric materials. It could also support academic polymer processing engineering programmes.