Extrusion Dies for Plastics & Rubber - Design & Engineering Computations.

Author : C Hopmann , W Michaeli | Edition : 4th | 2016 | 470 pages

This definitive book provides a comprehensive account of the full range of dies used for extrusion of plastics and elastomers. The distinctive features of the various types of dies are described in detail. Expert advice on the configuration of dies is given, and the possibilities of computer-aided design, as well as its limitations, are demonstrated.

Fundamentals and computational procedures are clearly explained so that no special prior knowledge of the subject is required. The mechanical configuration, handling, and maintenance of extrusion dies are described. Calibration procedures for pipes and profiles are also discussed.

This book was written for plastics engineers who need daily support in their practical work in industry and science, as well as for students preparing for their professional life.

This 4th edition is brought up to date with several important additions, including coverage of multilayer (>15 layer) dies, melt encapsulation, and simulation tools (rheological/thermal CFD simulations).

Table of Contents

PREFACE TO THE THIRD EDITION

PREFACE TO THE SECOND EDITION

PREFACE TO THE FIRST EDITION

INTRODUCTION

PROPERTIES OF POLYMERIC MELTS

Rheological Behavior

Viscous Properties of Melts

Viscosity and Flow Functions

Mathematical Description of the Pseudoplastic Behavior of

Influence of Temperature and Pressure on the Flow

Determination of Viscous Flow Behavior

Viscoelastic Properties of Melts

Thermodynamic Behavior

Density

Thermal Conductivity

Specific Heat Capacity

Thermal Diffusivity

Specific Enthalpy

FUNDAMENTAL EQUATIONS FOR SIMPLE FLOWS

Flow through a Pipe

Flow through a Slit

Flow through an Annular Gap

Summary of Simple Equations for Dies

Phenomenon of Wall Slip

Model Considering the Wall Slip

Instability in the Flow Function - Melt Fracture

COMPUTATION OF VELOCITY AND TEMPERATURE DISTRIBUTIONS IN EXTRUSION DIES

Conservation Equations

Continuity Equation

Momentum Equations

Energy Equation

Restrictive Assumptions and Boundary Conditions

Analytical Formulas for Solution of the Conservation Equations

Numerical Solution of Conservation Equations

Finite Difference Method

Finite Element Method

Comparison of FDM and FEM

Examples of Computations of Extrusion Dies

Consideration of the Viscoelastic Behavior of the Material

Computation of the Extrudate Swelling

Methods for Designing and Optimizing Extrusion Dies

Industrial Practice for the Design of Extrusion Dies

Optimization Parameters

Practical Optimization Objectives

Practical Boundary Conditions and Constraints When Designing Flow Channels

Independent Parameters during Die Optimization

Dependent Parameters during Die Optimization and Their

Optimization Methods

Gradient-Free Optimization Methods

Gradient-Based Optimization Methods

Stochastic Optimization Methods

Evolutionary Methods

Treatment of Boundary Conditions

Practical Applications of Optimization Strategies for the Design of Extrusion Dies

Optimization of a Convergent Channel Geometry

Optimization of Profile Dies

MONOEXTRUSION DIES FOR THERMOPLASTICS

Dies with Circular Exit Cross Section

Designs and Applications

Design

Dies with Slit Exit Cross Section

Designs and Applications

Design

T-Manifold

Fishtail Manifold

Coathanger Manifold

Numerical Procedures

Considerations for Clam Shelling

Unconventional Manifolds

Operating Performance of Wide Slit Dies

Dies with Annular Exit Cross Section

Types

Center-Fed Mandrel Support Dies

Screen Pack Dies

Side-Fed Mandrel Dies

Spiral Mandrel Dies

Applications

Pipe Dies

Blown Film Dies

Dies for the Extrusion of Parisons for Blow Molding

Coating Dies

Design

Center-Fed Mandrel Dies and Screen Pack Dies

Side-Fed Mandrel Dies

Spiral Mandrel Dies

Coating Dies

Formulas for the Computation of the Pressure Loss in Flow Channel Geometries other than Pipe or Slit

Dies with Irregular Outlet Geometry (Profile Dies)

Designs and Applications

Design

Dies for Foamed Semifinished Products

Dies for Foamed Films

Dies for Foamed Profiles

Special Dies

Dies for Coating of Profiles of Arbitrary Cross Section

Dies for the Production of Profiles with Reinforcing Inserts

Dies for the Production of Nets

Slit Die with Driven Screw for the Production of Slabs

COEXTRUSION DIES FOR THERMOPLASTICS

Designs

Externally Combining Coextrusion Dies

Adapter (Feedblock) Dies

Multimanifold Dies

Layer Multiplication Dies

Applications

Film and Sheet Dies

Blown Film Dies

Dies for the Extrusion of Parisons for Blow Molding

Computations of Flow and Design

Computation of Simple Multilayer Flow with Constant Viscosity

Computation of Coextrusion Flow by the Explicit Finite Difference Method

Computation of Velocity and Temperature Fields by the Finite Difference Method

Computation of Velocity Fields in Coextrusion Flows by FEM

Instabilities in Multilayer Flow

EXTRUSION DIES FOR ELASTOMERS

Design of Dies for the Extrusion of Elastomers

Fundamentals of Design of Extrusion Dies for Elastomers

Thermodynamic Material Data

Rheological Material Data

Computation of Viscous Pressure Losses

Formulas for Isothermal

Approaches to Nonisothermal Computations

Estimation of the Peak Temperatures

Consideration of the Elastic Behavior of the Material

Design of Distributor Dies for Elastomers

Design of Slotted Disks for Extrusion Dies for Elastomers

Computation of Pressure Losses

Extrudate Swelling (Die Swell)

Simplified Estimations for the Design of a Slotted Disk

HEATING OF EXTRUSION DIES

Types and Applications

Heating of Extrusion Dies with Fluids

Electrically Heated Extrusion Dies

Temperature Control of Extrusion Dies

Thermal Design

Criteria and Degrees of Freedom for Thermal Design

Heat Balance of the Extrusion Die

Restrictive Assumptions in the Modeling

Simulation Methods for Thermal Design

References of Chapter 8

MECHANICAL DESIGN OF EXTRUSION DIES

Mechanical Design of a Breaker Plate

Mechanical Design of a Die with Axially Symmetrical Flow Channels

Mechanical Design of a Slit Die

General Design Rules

Materials for Extrusion Dies

HANDLING, CLEANING, AND MAINTAINING EXTRUSION DIES

CALIBRATION OF PIPES AND PROFILES

Types and Applications

Friction Calibration

External Calibration with Compressed Air

External Calibration with Vacuum

Internal Calibration

Precision Extrusion Pullforming (the Technoform Process)

Special Process with Movable Calibrators

Thermal Design of Calibration Lines

Analytical Computational Model

Numerical Computational Model

Analogy Model

Thermal Boundary Conditions and Material Data

Effect of Cooling on the Quality of the Extrudate

Mechanical Design of Calibration Lines

Cooling Dies, Process for Production of Solid Bars

INDEX.