This book provides the background needed to understand not only the wide field of polymer processing, but also the emerging technologies associated with the plastics industry in the 21st century. It combines practical engineering concepts with modeling of realistic polymer processes. Divided into three sections, it provides the reader with a solid knowledge base in polymer materials, polymer processing, and modeling. "Understanding Polymer Processing" is intended for the person who is entering the plastics manufacturing industry and as a textbook for students taking an introductory course in polymer processing. It also serves as a guide to the practicing engineer when choosing a process, determining important parameters and factors during the early stages of process design, and when optimizing such a process. Practical examples illustrating basic concepts are presented throughout the book. New in the third edition are chapters on data-driven modeling and physics-driven modeling, as well as new sections on manufacturing and dimentional analysis. In addition to a number of other smaller improvements and corrections throughout the book, bonus code downloads are also providided. Contents: Part I: Polymeric Materials This section gives a general introduction to polymers, including mechanical behavior of polymers and melt rheology. Part II: Polymer Processing The major polymer processes are introduced in this section, including extrusion, mixing, injection molding, thermoforming, blow molding, film blowing, and many others. Part III: Modeling This last section delivers the tools to allow the engineer to solve back-of-the-envelope polymer processing models. It includes dimensional analysis and scaling, transport phenomena in polymer processing, and modeling polymer processes.