All new and totally updated, the second edition of this well received book presents a summary of the important formulas and their applications, which the author, in cooperation with well known resin and machine manufacturers, successfully applied to solve design and processing problems. The formulas are classified according to specific fields, rheology, thermodynamics, heat transfer, and part design. Each chapter covers the relevant relations with detailed examples. A separate chapter is devoted to the practical equations for designing extrusion and injection molding equipment with detailed examples in metric units. In addition, this work contains new, straightforward, practical relationships that have been developed and tested in recent years for solving design problems in the area of extrusion and injection molding. Practical examples provide the computational background of designing polymer machinery in a manner that every engineer can understand and easily apply in daily practice.