Analyzing and troubleshooting single-screw extruders

The book teaches the fundamentals of single-screw extrusion such that fast troubleshooting and process optimization and design are possible. The fundamental processes that are occurring in the machine are developed from the natural reference point of a rotating screw rather the traditional rotating barrel. These fundamentals are then combined with the chemistry of polymers and the physical properties related to processing to troubleshoot and optimize extrusion processes. Many industrial extrusion problem case studies are presented. In each case study, the root cause of the problem is identified along with the solution. A fundamental view of the processes that occur in a single-screw machine from the natural reference frame; i.e., screw rotation. The theory is discussed and compared to experimental data and to a rotating barrel reference frame. Topics include: polymerization chemistry and degradation mechanisms for polymers, physical properties related to processing (e.g., rheology, heat capacity, dynamic friction, bulk density and pellet compaction, melt density), and 30+ case studies for troubleshooting extrusion problems. A detailed description of the problem and the solution is presented so the reader can implement the solution on their own equipment. Prior extrusion books are based on barrel rotation physics—this is the first book that focuses on the actual physics of the process—screw rotation physics. In the first nine chapters, theories and math models are developed. Then, these models are used to solve actual commercial problems in the remainder of the book. Realistic case studies are presented that are unique in that they describe the problem as viewed by a typical plant engineer and provide the actual dimensions of the screws. Overall, there is not a book on the market with this level of detail and disclosure. The new knowledge in this book will be highly useful for production engineers, technical service engineers working with customers, consultants specializing in troubleshooting and process design, and process researchers and designers that are responsible for processes that running at maximum rates and maximum profitability.Contents:oIntroduction & TroubleshootingoPolymer MaterialsoIntroduction to Polymer Rheology for ExtrusionoResin Physical Properties Related to ProcessingoSolids ConveyingoThe Melting ProcessoFluid Flow in Metering ChannelsoMixing Processes for Single-Screw Extruders oScaling of Single-Screw Extrusion ProcessesoIntroduction to Troubleshooting the Extrusion ProcessoContaminations in the Finished ProductoFlow Surging oRate-Limited Extrusion Processes oBarrier and High-Performance ScrewsoMelt-Fed Extruders