Specialized Molding Techniques - Application, Design, Materials and Processing

Specialized Molding Techniques - Application, Design, Materials and Processing

Author: Hans-Peter Heim and Helmut Potente
10-ISBN 1-884207-91-X 
13-ISBN 978-1-884207-91-4 
University of Paderborn, Germany

Pages: 317, Figures: 207, Tables: 45

A surge of new molding technologies is transforming plastics processing and material forms to the highly efficient, integrated manufacturing that will set industry standards in the early years of this century. Many of these emerging material-process technologies discussed in this book include: gas-assisted injection molding, fusible core injection molding, low pressure injection molding (including laminate molding and liquid-gas assist molding), advanced blow molding, thermoplastic sheet composite processing, reactive liquid composite molding, microcellular plastics, lamellar injection molding, and multi-material, multiprocess technology, coinjection, in-mold decoration, encapsulation, stack molding, micro-injection molding, fusible core, vibration-assisted, injection molding extrusion, surface replication and direct compounding. The main emphasis is given to thin-wall molding, gas-assist molding, and vacuum assisted resin transfer molding. To put these new technologies in a context and to accentuate opportunities, the relations among these technologies are analyzed in terms of

Products: auto parts (e.g. bumpers, trim, keyless entry module, blower switch housing), business machines chassis, pallets, furniture, handles, television housings, covers, golf club shafts, connectors, notebook casing, switches, sensors, antennas, sockets, lighting, cellular phone housing, submicron parts, and medical devices.
Materials: composition, resin consideration, blends, structure (skin/core), shrinkage, viscosity, weld line strength, structural properties, morphology, reinforcement, surface roughness
Processing: macroscopic structure, size and shape, typical problems and their solutions, flow length, injection pressure prediction, process simulation, processing parameters, tooling issues, rheology, rheokinetics, flow equations, flow simulation, no-slip boundary conditions, pressure loss, surface appearance, manufacturing cost, leakage modelling, set-up criteria, optimization of molding parameters non-return valve applications.
Geometry: function (enclosure/support) and complexity (symmetric/three-dimensional), molding window, filling of a complex part, design optimization, x-ray tomography, image reconstruction, acoustic imaging, warpage calculation, simulation and calculation, flow channels, and tight tolerance.
Review of manufacturers, licenses, required investment in equipment, and cost benefits expected in return.
This is in addition to evaluation of hardware, processing parameters, problems, and results of the application of these processes. The examples of some other processes involved include: photoimaging, in-mold circuit definition, two-shot, one-shot, two-cavity shuttle design, valve gate technology, low-pressure injection molding, in-mold decoration, plating, in-mold assembly, sandwich molding, and large part molding.

Gas-Assisted Injection Molding
Fusible Core Injection Molding
Low-Pressure Injection Molding (including laminate molding and liquid-gas assist molding)
Advanced Blow Molding
Thermoplastic Sheet Composite Processing
Reactive Liquid Composite Molding
Microcellular Plastics
Lamellar Injection Molding
Multimaterial/Multiprocess Technology
In-Mold Decoration
Stack Molding
Microinjection Molding
Fusible Core
Injection Molding Extrusion
Surface Replication
Direct Compounding

Hans-Peter Heim studied engineering and business administration at the University of Paderborn in Germany. He completed his diploma thesis in 1996 at an automotive supplier company in Italy. Following this, he carried out different projects on quality assurance and quality improvement in plastics processing at this same company. Since 1997 he has worked in the field of gas-assisted injection molding, quality improvement and quality assurance in Prof. Dr.-Ing. H. Potente's group at the KTP Institute of Plastics Engineering in Paderborn. He has been chief engineer at the KTP since 1999. He completed his Ph.D. thesis on gas-assisted injection molding in March 2001.

Professor Dr.-Ing. Helmut Potente gained his doctorate at the IKV Institute of Plastics Processing at Aachen University of Technology. From 1971 to 1974 he was head of the Plastics Process Engineering Laboratory at Westfälische Metallindustrie KG Hueck & Co. in Lippstadt/Germany. In 1974 he was appointed an academic officer and Professor of Joining, Forming and Refining Technology for Plastics at Aachen University of Technology. Since 1980 he has held the Chair of Plastics Engineering at the University of Paderborn and been Head of the Institute of Plastics Processing.