Search results for ""author gregory a. campbell""

Single-screw or twin-screw extruder? When the need to produce a homogeneous polymer melt occurs in the industrial environment, both product attributes and equipment cost must be evaluated. For many applications both the single and twin-screw extruder will produce the desired homogeneous melt needed to form the product through an extrusion die. Some applications such as dispersive mixing of solids in a polymer matrix are best accomplished in a twin-screw extruder. On the other hand, applications involving chemical reactions, color concentrate distributive mixing, and in line polymer-polymer distributive mixing can be accomplished with either device.However, for the same production rate, twin-screw extruders are generally more expensive than single-screw extruders with a diameter less than 200 mm. Therefore, a thorough understanding is needed for the concepts of solids conveying, melting, and mixing for the two types of extruders to make appropriate process acquisition decisions. This book covers engineering and technology concepts that should aid the practitioner in comparing these two types of extrusion equipment relative to process requirements.The handbook is intended for newcomers interested in the theoretical and regulatory aspects of validation and for thermal analysis practitioners who have to validate their equipment and methods.

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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. The second edition is brought up to date with a significant amount of new content, as well as minor improvements and correction of errors throughout.The new content includes transfer lines, percolation theory, fillers, and several more case studies.

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