Hot Runner Technology

Contents

Preface

1 Introduction

1.1 General Aspects of Hot Runner Technology

1.2 Design of Hot Runner Systems and Nomenclature of Components

1.3 Design of Single Components Used for Hot Runner Systems

References for Chapter 1

2 Basic Aspects of Heat Technology

2.1 Heat Transfer

2.1.1 Heat Conduction

2.1.2 Convection

2.1.3 Radiation

2.1.4 Summary

2.2 Amount of Heat, Heating Capacity

2.3 Heat Expansion

References for Chapter 2

3 Introduction of Hot Runner Components

3.1 Hot Runner Manifold Block

3.1.1 Externally Heated Hot Runner Manifold Blocks

3.1.2 Internally Heated Hot Runner Manifold Blocks

3.1.3 Insulated Runner System

3.1.4 Rheological Design

3.2 Reflector- and Thermal Insulating Sheets, Surface Coating

3.3 Melt Chamber Bushing

3.4 Distributor Bushing

3.5 Spacer Disks

3.6 Anti-Twist Device for Hot Runner Block

3.7 Turn Plugs

3.8 Hot Runner Nozzles

3.8.1 General Aspects

3.8.2 Open Hot Runner Nozzle

3.8.3 Open Multiple Gate Nozzles

3.8.4 Shut-Off Nozzles

References for Chapter 3

4 Heating of Hot Runner Manifold Blocks

4.1 Cylindrical Cartridge Heater

4.2 Tapered Cartridge Heater

4.3 Threaded Cartridge Heater

4.4 Tubular Heater

4.5 Heater Plate

4.6 “Thick-Film”- Heating Element

4.7 Indirect Heating Using a Liquid Medium

4.8 Heat Pipe

4.9 Determination of Heating Capacity of an Externally Heated Hot Runner Manifold Block

4.9.1 Estimate of Required Heating Capacity

4.9.2 Numerical Determination of Heating Capacity to be Installed for the Heat-up Phase

References for Chapter 4

5 Heating of Hot Runner Nozzles

5.1 Cylindrical Cartridge Heater

5.2 Coiled Heater

5.3 Resistor Heater

5.4 Heat Pipe

5.5 Indirect Heating Using a Liquid Medium

5.6 General Remarks Regarding Internal Heating (“Conductive Heating”)

5.7 Indirect Heating

5.7.1 Thermally Conductive Torpedoes

5.7.2 Thermally Conductive Nozzle

References for Chapter 5

6 Measurement and Control of Temperature

7 Material Behavior under Mechanical Load

7.1 Notch Effect under Static Load

7.2 Notch Effect under Dynamic Load

References for Chapter 7

8 Corrosion and Wear

References for Chapter 8

9 Screw Connections and Material Selection for Elevated Temperatures

References for Chapter 9

10 Basic Aspects of Plastics Technology

10.1 Flow Characteristics, Viscosity, Pressure Loss

10.2 Thermal Stability

10.3 Decrease of Molecular Weight (Exemplified by PBT)

10.3.1 Thermal Degradation

10.3.2 Mechanical Degradation

10.3.3 Oxidative Degradation

10.3.4 Hydrolytic Degradation

References for Chapter 10

11 Maintenance and Storage of Hot Runner Molds

References for Chapter 11

12 Design of Special Hot Runner Systems and Hot Runner Molds

12.1 300-Fold Hot Runner System for the Production of Transistor Housings Made of Reinforced PBT

12.2 Hot Runner Manifold Block for Sandwich Molding

12.3 Hot Runner System with Balanced Filling Action

12.4 Hot Runner Nozzles for Small Center-to-Center Cavity Space

References for Chapter 12

Appendix 1: Abbreviations Used in this Book

Appendix 2: Conversion Factors for Units of Measure

Index