This book is aimed at scientists and practicing engineers who are currently exploring or would like to explore the complexity of fabrication processes of polymer composites. It deals with the mechanics and modeling aspects of discontinuous and continuous fiber composites and familarizes the engineer with the critical and fundamental issues of material processing and transport phenomena in polymeric composites and their applications in modeling and simulating specific composite manufacturing processes. Divided into three parts, Part A deals with the deformation science or rheology of these filled materials. It clearly shows the need to characterize their flow behavior before one can draw any conclusions about its processibility during manufacturing. Part B focuses on development of constitutive equations to describe the flow and deformation behavior of such materials under external processing conditions. Part C discusses the mathematical models for selected composite processes and their implementation into a computer simulation to analyze the process behavior. The processes represented in Part C cover a cross-section of important manufacturing processes and maintain a balance between processes that use short fibers and continuous fibrous materials.