[PDF] Model Development And Validation Of A Ceramic Core Injection Molding Process eBook

Author : B.C. Mutsuddy
Publisher : Springer Science & Business Media
Page : 386 pages
File Size : 35,63 MB
Release : 1994-11-30
Category : Technology & Engineering
ISBN : 9780412538100

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This book provides a comprehensive overview of the steps involved in the ceramic injection molding process. It provides the reader with a convenient and authoritative source of information and guidance on the use of materials, equipment and testing procedures to produce satisfactory ceramic products.

Author : Jaime N. Castaneda
Publisher :
Page : 60 pages
File Size : 17,52 MB
Release : 2006
Category :
ISBN :

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To reduce costs and hazardous wastes associated with the production of lead-based active ceramic components, an injection molding process is being investigated to replace the current machining process. Here, lead zirconate titanate (PZT) ceramic particles are suspended in a thermoplastic resin and are injected into a mold and allowed to cool. The part is then bisque fired and sintered to complete the densification process. To help design this new process we use a finite element model to describe the injection molding of the ceramic paste. Flow solutions are obtained using a coupled, finite-element based, Newton-Raphson numerical method based on the GOMA/ARIA suite of Sandia flow solvers. The evolution of the free surface is solved with an advanced level set algorithm. This approach incorporates novel methods for representing surface tension and wetting forces that affect the evolution of the free surface. Thermal, rheological, and wetting properties of the PZT paste are measured for use as input to the model. The viscosity of the PZT is highly dependent both on temperature and shear rate. One challenge in modeling the injection process is coming up with appropriate constitutive equations that capture relevant phenomenology without being too computationally complex. For this reason we model the material as a Carreau fluid and a WLF temperature dependence. Two-dimensional (2D) modeling is performed to explore the effects of the shear in isothermal conditions. Results indicate that very low viscosity regions exist near walls and that these results look similar in terms of meniscus shape and fill times to a simple Newtonian constitutive equation at the shear-thinned viscosity for the paste. These results allow us to pick a representative viscosity to use in fully three-dimensional (3D) simulation, which because of numerical complexities are restricted to using a Newtonian constitutive equation. Further 2D modeling at nonisothermal conditions shows that the choice of representative Newtonian viscosity is dependent on the amount of heating of the initially room temperature mold. An early 3D transient model shows that the initial design of the distributor is sub-optimal. However, these simulations take several months to run on 4 processors of an HP workstation using a preconditioner/solver combination of ILUT/GMRES with fill factors of 3 and PSPG stabilization. Therefore, several modifications to the distributor geometry and orientations of the vents and molds have been investigated using much faster 3D steady-state simulations. The pressure distribution for these steady-state calculations is examined for three different distributor designs to see if this can indicate which geometry has the superior design. The second modification, with a longer distributor, is shown to have flatter, more monotonic isobars perpendicular to the flow direction indicating a better filling process. The effects of the distributor modifications, as well as effects of the mold orientation, have also been examined with laboratory experiments in which the flow of a viscous Newtonian oil entering transparent molds is recorded visually. Here, the flow front is flatter and voids are reduced for the second geometry compared to the original geometry. A horizontal orientation, as opposed to the planned vertical orientation, results in fewer voids. Recently, the Navier-Stokes equations have been stabilized with the Dohrman-Bochev PSPP stabilization method, allowing us to calculate transient 3D simulations with computational times on the order of days instead of months. Validation simulations are performed and compared to the experiments. Many of the trends of the experiments are captured by the level set modeling, though quantitative agreement is lacking mainly due to the high value of the gas phase viscosity necessary for numerical stability, though physically unrealistic. More correct trends are predicted for the vertical model than the horizontal model, which is serendipitous as the actual mold is held in a vertical geometry. The full, transient mold filling calculations indicate that the flow front is flatter and voids may be reduced for the second geometry compared to the original geometry. The validated model is used to predict mold filling for the actual process with the material properties for the PZT paste, the original distributor geometry, and the mold in a vertical orientation. This calculation shows that voids may be trapped at the four corners of the mold opposite the distributor.

Author : Jinlong Yang
Publisher : Springer Nature
Page : 568 pages
File Size : 23,2 MB
Release : 2020-01-28
Category : Technology & Engineering
ISBN : 9811518726

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This book discusses several new, near-net-shape techniques for fabricating highly reliable, high-performance, complex ceramic parts. In the context of materials design, the creation of high-performance ceramic products of desired shapes has led to the need for new ceramic forming processes. The near-net-shape techniques combine both injection-molding and colloidal-forming processes. Reviewing and summarizing the research and latest advances, the book is divided into 6 parts: (1) the basic theory, development, and application of the colloidal injection molding of ceramics; (2) the tape casting technology; (3) the reliability of the product; (4) the colloidal injection molding of Si3N4 and SiC; (5) low-toxicity systems; and (6) the novel in-situ coagulation casting of ceramic suspensions via controlled release of high-valence counter ions and dispersant removal. It is intended for researchers and graduates in materials science and engineering.

Author : David O. Kazmer
Publisher : Carl Hanser Verlag GmbH Co KG
Page : 446 pages
File Size : 33,81 MB
Release : 2012-11-12
Category : Technology & Engineering
ISBN : 3446434194

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This book provides a vision and structure to finally synergize all the engineering disciplines that converge in the mold design process. The topics are presented in a top-down manner, beginning with introductory definitions and the "big picture" before proceeding to layout and detailed design of molds. The book provides very pragmatic analysis with worked examples that can be readily adapted to "real world" mold design applications. It should help students and practitioners to understand the inner workings of injection molds and encourage them to think "outside the box" in developing innovative and highly functional mold designs. Contents: · Introduction to mold functions, types, and components · Review of design for injection molding · Cost estimation and optimization · Mold layout design including cavity layout, sizing, and materials selection · Cavity, runner system, and gating analysis and design · Cooling system analysis and design · Venting, shrinkage, and warpage analysis and strategies · Ejection force analysis and ejection system designs · Stress and deflection analysis with structural system designs · A survey of advanced mold designs

Author : M. Joseph Gordon, Jr.
Publisher : John Wiley & Sons
Page : 766 pages
File Size : 33,75 MB
Release : 2010-03-25
Category : Technology & Engineering
ISBN : 0470584483

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The all-encompassing guide to total quality process control for injection molding In the same simple, easy-to-understand language that marked the first edition, Total Quality Process Control for Injection Molding, Second Edition lays out a successful plan for producing superior plastic parts using high-quality controls. This updated edition is the first of its kind to zero in on every phase of the injection molding process, the most commonly used plastics manufacturing method, with an all-inclusive strategy for excellence. Beginning with sales and marketing, then moving forward to cover finance, purchasing, design, tooling, manufacturing, assembly, decorating, and shipping, the book thoroughly covers each stage to illustrate how elevated standards across individual departments relate to result in the creation of a top-notch product. This Second Edition: Details ways to improve plastic part design and quality Includes material and process control procedures to monitor quality through the entire manufacturing system Offers detailed information on machinery and equipment and the implementation of quality assurance methods—content that is lacking in similar books Provides problem-analysis techniques and troubleshooting procedures Includes updates that cover Six Sigma, ISO 9000, and TS 16949, which are all critical for quality control; computer-guided process control techniques; and lean manufacturing methods With proven ways to problem-solve, increase performance, and ensure customer satis-faction, this valuable guide offers the vital information today's managers need to plan and implement quality process control—and produce plastic parts that not only meet, but surpass expectations.

Author : D.V. Rosato
Publisher : Springer Science & Business Media
Page : 1484 pages
File Size : 14,76 MB
Release : 2012-12-06
Category : Technology & Engineering
ISBN : 1461545978

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This third edition has been written to thoroughly update the coverage of injection molding in the World of Plastics. There have been changes, including extensive additions, to over 50% of the content of the second edition. Many examples are provided of processing different plastics and relating the results to critiCal factors, which range from product design to meeting performance requirements to reducing costs to zero-defect targets. Changes have not been made that concern what is basic to injection molding. However, more basic information has been added concerning present and future developments, resulting in the book being more useful for a long time to come. Detailed explanations and interpretation of individual subjects (more than 1500) are provided, using a total of 914 figures and 209 tables. Throughout the book there is extensive information on problems and solutions as well as extensive cross referencing on its many different subjects. This book represents the ENCYCLOPEDIA on IM, as is evident from its extensive and detailed text that follows from its lengthy Table of CONTENTS and INDEX with over 5200 entries. The worldwide industry encompasses many hundreds of useful plastic-related computer programs. This book lists these programs (ranging from operational training to product design to molding to marketing) and explains them briefly, but no program or series of programs can provide the details obtained and the extent of information contained in this single sourcebook.