Download or read book Extensional Flow Induced Crystallization in Polyethylene Melt Spinning written by Vikas Madhusudan Nadkarni and published by . This book was released on 1974 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rheo Physics of Multiphase Polymer Systems written by Kai Sondergaard and published by CRC Press. This book was released on 1995-06-02 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt: FROM THE PREFACE Almost all polymeric systems are subjected to a flow field at least once along the route between preparation and application. . . . There is also an increased interest in predictive models on phase behavior and suitable techniques for characterizing the structure of these systems when subjected to flow. Multiphase polymeric systems are particularly susceptible to flow, which may cause orientation of species, morphological changes, and phase transitions. All these events may, in turn, affect the end product properties, such as permeability, electrical conductivity, [and] mechanical properties. In processing, escalating needs have evolved for optimization and development of novel and more uniform product properties and increased productivity. In order to arrive at an understanding of processing polymeric systems under elastic flow conditions, it is convenient to analyze the basic physical mechanisms under conditions that enable development of predictive models in conjunction with controlled experimentation. . . . In recent years, the science of rheo-physics has evolved and now involves both advanced theories and experimental techniques. Rheo-physics means the rheological, morphological, and thermodynamic behavior of structured polymer systems during flow. . . . In this monograph, the rheo-optical techniques are . . . emphasized. The book gives an introduction to rheo-physics, including fundamentals of theories, and a representative selection of applications of rheo-optical techniques for analyzing multiphase systems. The chapters contain both practical advice for the new experimenter . . . as well as review material for the experienced scientist.
Download or read book Extensional flow induced Crystallization of Polypropylene written by Erica E. Bischoff White and published by . This book was released on 2011 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: A filament stretching extensional rheometer was used to investigate the effect of uniaxial flow on the crystallization of polypropylene. Samples were heated to a temperature above the melt temperature to erase their thermal and mechanical histories. The Janeschitz-Kriegl protocol was applied and samples were stretched at various extension rates to a final strain of e = 3.0. Differential scanning calorimetry was applied to crystallized samples to measure the degree of crystallinity. The results showed that a minimum extension rate, corresponding to a Weissenberg number of approximately Wi = 1, is required for an increase in percent crystallization to occur. Below this Weissenberg number, the flow is not strong enough to align the tubes of constrained polymer chains and as a result there is no change in the final percent crystallization. An extension rate was also found for which percent crystallization is maximized. The increase in crystallinity is likely due to flow-induced orientation and alignment of tubes of constrained polymer chains. Polarized-light microscopy verified an increase in number and decrease in size of spherulites with increasing extension rate. Small angle X-ray scattering showed a 7% decrease in inter-lamellar spacing at the transition to flow-induced increase in crystallization. Crystallization kinetics were examined by observing the time required for melts to crystallize under uniaxial flow. The crystallization time decreased with increasing extension rate, even for extension rates where no increase in percent crystallization was observed. These results demonstrate that the speed of crystallization kinetics is greatly enhanced by the application of extensional flow.
Download or read book On the Kinetics of Flow Induced Crystallization of Polyethylene Melt Above Its Normal Melting Point 8 written by Victor Tan and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flow Induced Crystallization of Polymers written by Gaetano Guerra and published by Wiley-VCH. This book was released on 2002-12-20 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: In polymer processing, the molecular orientation induced by flow has a significant effect on the crystallization kinetics and final morphology of the polymer produced. The impact on processing operations and object properties is extremely important and recently scientific and technological researchers have begun to quanitify these effects. The international conference 'Flow-Induced Crystallization of Polymers', held in October 2001 in Salerno, Italy, was timely and well attended. An interdisciplinary approach was taken and presentations were made on topics ranging from real-time measurement, through modelling, to final morphology and properties of polymers. Invited and other selected contributions from the conference are collected here, in this volume of Macromolecular Symposia
Download or read book Journal of Rheology written by and published by . This book was released on 2007 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Industrial Polyethylene and Technology written by Mark A. Spalding and published by John Wiley & Sons. This book was released on 2017-10-26 with total page 1671 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook provides an exhaustive description of polyethylene. The 50+ chapters are written by some of the most experienced and prominent authors in the field, providing a truly unique view of polyethylene. The book starts with a historical discussion on how low density polyethylene was discovered and how it provided unique opportunities in the early days. New catalysts are presented and show how they created an expansion in available products including linear low density polyethylene, high density polyethylene, copolymers, and polyethylene produced from metallocene catalysts. With these different catalysts systems a wide range of structures are possible with an equally wide range of physical properties. Numerous types of additives are presented that include additives for the protection of the resin from the environment and processing, fillers, processing aids, anti-fogging agents, pigments, and flame retardants. Common processing methods including extrusion, blown film, cast film, injection molding, and thermoforming are presented along with some of the more specialized processing techniques such as rotational molding, fiber processing, pipe extrusion, reactive extrusion, wire and cable, and foaming processes. The business of polyethylene including markets, world capacity, and future prospects are detailed. This handbook provides the most current and complete technology assessments and business practices for polyethylene resins.
Download or read book Properties of Solid Polymeric Materials written by J. M. Schultz and published by Elsevier. This book was released on 2013-10-22 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: Treatise on Materials Science and Technology, Volume 10: Properties of Solid Polymeric Materials, Part A covers knowledge in the critical areas of polymeric materials. The book provides a background in polymer structure and morphogenesis, and discusses rubberlike elasticity, a phenomenon thermodynamically unique to long-chain polymers. The text also describes the mechanics of anisotropie, oriented polymeric systems and of glassy polymers. The fatigue behavior in solid polymers and the electrical properties of solid polymers are also reviewed. The book further tackles the electron processes and electrical breakdown in polymers. The text concludes with a discussion of the role of the environment on the integrity of polymeric solids. Materials scientists, materials engineers, and graduate students taking related courses will find the book useful.
Download or read book Flow Induced Crystallization by Surface Growth of Polyethylene Fibers written by Jeroen Rietveld and published by . This book was released on 1982 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flow induced Crystallization in Polymer Systems written by Robert L. Miller and published by Taylor & Francis. This book was released on 1979-01-01 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crystallization Kinetics of Polymer Melts in Extensional Flow written by David Alan Tree and published by . This book was released on 1990 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: A technique to study the kinetics of flow-induced crystallization of polymers in extensional flow has been developed which uses a 4-Roll Mill. The kinetics of a High Density Polyethylene were found to be well described by the Avrami treatment, indicated that the crystallization occurred by sporadic nucleation and one-dimensional growth and were a strong function of temperature and applied stress but were independent of strain history. The kinetics were found to be consistent with the Ziabicki theory for strain-induced crystallization but inconsistent with the theory of uttermost uniformity and an elevated melting point mechanism. The kinematics and stress fields of the 4-Roll Mill flow were measured independently by a tracer particle technique and an application of the Method of Isoclinics respectively allowing comparison to the predictions of several rheological equations of state. The deformation of a polymer droplet suspended in a carrier phase at low Reynolds number and high Weber number was documented. It is recommended that the 4-Roll Mill technique be used for study of other crystallizable polymer systems.
Download or read book Elastic Behavior of Polymer Melts written by Helmut Münstedt and published by Carl Hanser Verlag GmbH Co KG. This book was released on 2019-07-08 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the elastic properties of polymer melts is necessary for ensuring successful polymer processing and thus producing high-quality plastic parts. This unique book is the first to focus on this important topic. Starting with the molecular origin of elastic behavior and an explanation of the physical quantities involved, experimental methods and the dependence of elastic behavior on experimental parameters are then presented. Elastic properties of filled and unfilled systems are compared directly, and polymer blends are also considered. Elastic effects in various applications are included, such as in extrudate swell, internal stresses, and shrink films, to illustrate the importance of this field in the plastics processing industry.
Download or read book Flow Crystallization of Polyethylene in Extensional Flow Developed by Convergent Capillaries written by Jerry Byron Hare and published by . This book was released on 1977 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling and Simulation of Crystallization Processes in Polymer Melt Flows written by Stefan Descher and published by BoD – Books on Demand. This book was released on 2020-01-01 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describing crystallization processes in polymer melt flows involves many effects. Objective of this work is to capture a selection in a simulation environment, for a certain material, starting from executing experiments on. This means aspects of experimental investigations, modeling and special numerical methods used to create a simulation environment will be highlighted. Because this involves many fields, works covering all aspects are rare1. It is intended to contribute such a work by the publication of this thesis.
Download or read book Theoretical Investigation of Flow induced Crystallization in Fiber Spinning written by Jaydeep Avinash Kulkarni and published by . This book was released on 2000 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crystallization Modalities in Polymer Melt Processing written by Hermann Janeschitz-Kriegl and published by Springer. This book was released on 2018-03-27 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: In addition to structure formation in crystallizing polymers and semicrystalline polymers, this second edition completes the topic of transport phenomena. It also reviews solidification by crystallization during cooling and under flow or pressure, which all play an enormous role in polymer melt processing. Generally, there is an intensive interaction between three transport phenomena: heat transfer, momentum transfer (flow, rheology) and (flow induced) crystallization. The strong interaction between the three transport phenomena is a major challenge when it comes to experimentation, and advances in this area are detailed in the book, guiding further development of sound modeling. This book enables readers to follow an advanced course in polymer processing. It is a valuable resource for polymer chemists, applied physicists, rheologists, plastics engineers, mold makers and material scientists.
Download or read book Textile Technology Digest written by and published by . This book was released on 1997 with total page 758 pages. Available in PDF, EPUB and Kindle. Book excerpt:
