Scientific Injection Molding Tools.

Format:

Book

Author/Creator:

Valero, Jose R. Lerma., author.

Language:

English

Subjects (All):

Scientific literature.

Physical Description:

1 online resource (0 pages)

Edition:

1st ed.

Place of Publication:

München : Carl Hanser Verlag, 2024.

Summary:

This book provides a user-friendly guide to the implementation of Scientific Injection Molding, a proven methodology to ensure robust and reliable mass production of plastic parts.Readers will gain a clear understanding of their machines and especially their condition and behavior through on-site tests, of the polymers that will be processed, and of the necessary equipment for the application of this methodology in production plants. All the tests and tools that Scientific Injection Molding proposes are explained in detail so they can be readily applied.Performing the validation of a mold or process correctly, establishing the limits of the process window or molding area through the design of experiments, and transferring processes from one machine to another, assuring their repeatability, are skills presented as fundamental tools of the modern injection molder.Content:1 Scientific Injection Molding Advanced Steps toward Implementation2 Knowing Our Machines3 Knowing the Reliability and Performance of Injection Molding Machines4 Understanding Plastic Materials5 Required Information for Defining the Process6 Necessary Equipment for Advanced Injection Molding7 Tools for Scientific Injection Molding8 Top Ten Key Parameters in the Definition of the Injection Molding Process9 Process Portability, DOE (Design of Experiments), Mold Qualification and Process Validation10 Melt Preparation11 Process Variability, Self-Adaptation, and Corrections12 Data To Be Collected for the Calculation and Performance of a Scientific Injection Molding Process Methodology13 Reference Data Tables.

Contents:

Intro

Acknowledgments

Preface

The Author

Contents

1 Scientific Injection Molding - Advanced Steps toward Implementation

1.1 Introduction

1.2 Scientific Injection Molding or Injection with Advanced Methods - What Is It?

1.2.1 The Cultural Change Involved Moving from the Empirical to the Scientific Method

1.2.2 Training and Applying Scientific Molding Tools

1.2.3 Some Definitions

1.2.4 Process Inputs and Outputs

1.2.5 New Tools for Process Definition

1.2.6 Scientific Injection Molding or Injection with Advanced Methods

1.3 Who Should Be Trained in This Methodology and Where?

1.4 Where to Apply Scientific Injection Molding

1.5 Failures in the Implementation of Scientific Injection Molding

2 Knowing Our Machines

2.1 The Injection Molding Machine

2.2 Clamping Unit

2.2.1 Clamping Force

2.2.2 Clamping Unit Systems

2.2.3 Theoretical Clamping Force Required

2.3 Injection Unit

2.4 Screw

2.4.1 The Screw-Barrel Mode of Action

2.4.2 The Rotational Movement of the Screw Mode of Action

2.5 The Pressure Multiplier

2.6 The Right Injection Molding Machine

3 Knowing the Reliability and Performance of Injection Molding Machines

3.1 Mold Filling Time Repeatability Test

3.2 Load Sensitivity Test

3.2.1 Machine Configuration for Carrying Out the Pressure Compensation Test

3.2.2 Spreadsheet for the Load Sensitivity Test

3.3 Delta P Test

3.4 Screw Tip/Check Ring Valve Sealing Test

3.4.1 Dynamic Test

3.4.2 Static Test

3.4.2.1 Injection Machine Configuration for Carrying Out the Screw Tip/Check Ring Valve Sealing Test

3.4.2.2 What about Hot Runners?

3.5 Injection-Speed Linearity Test

3.6 Screw Acceleration Test

3.7 Pressure Response Test

3.8 Other Tests

3.9 Application Diagram of Injection Molding Machine Reliability and Performance Tests

4 Understanding Plastic Materials

4.1 Classification and Properties of Plastics According to Molecular Structure

4.1.1 Amorphous Thermoplastics

4.1.2 Semi-Crystalline Thermoplastics

4.1.3 Elastomers

4.2 Classification of Thermoplastics According to Molecular Chain Form

4.2.1 Homopolymer

4.2.2 Copolymer

4.3 Rheology

4.3.1 Elastic Deformation

4.3.2 Viscosity

4.4 Glass Transition Temperature (Tg)

4.5 Melting Temperature (Tm)

4.6 Thermoplastics Behavior

4.7 Behavior under Load

4.7.1 Maxwell-Voigt Model

4.7.2 Creep and Relaxation

4.8 Thermodynamic Behavior of Plastics: PVT Graphs

4.8.1 Thermodynamics Definitions

4.8.2 PVT Graphs

4.8.2.1 Metering Phase: Plasticization, Melting

4.8.2.2 Injection Phase: Filling the Mold

4.8.2.3 Holding Pressure Phase

4.8.2.4 Cooling Phase

4.8.3 Main Points of the PVT Graph

4.8.4 Main Effects and Properties of Each Injection Molding Phase on the Material

4.8.5 Influence of Injection Molding Parameters Reflected in PVT Graphs

4.9 Crystallization Phases

4.9.1 Defects or Errors Caused during the Crystallization Phase

4.9.2 Degree of Crystallization, an Injection Molding Technician's Responsibility

5 Required Information for Defining the Process

5.1 Plastics Properties: Data Sheet Interpretation

5.1.1 Examples of Data Sheets

5.1.2 Density

5.1.3 Material Flow Rates

5.1.3.1 Melt Volume Index (MVI)

5.1.3.2 Melt Flow Index (MFI)

5.1.3.3 Comparing Materials' Fluidity

5.1.4 Melting Temperatures

5.1.5 Mechanical Properties

5.1.5.1 Tensile Stress and Mechanical Resistance

5.1.5.2 Elastic and Tensile Moduli

5.1.5.3 Impact Strength

5.1.6 Thermal Properties

5.1.6.1 Coefficient of Linear Thermal Expansion (CLTE)

5.1.6.2 Vicat Softening Temperature

5.1.6.3 Heat Deflection Temperature (HDT/HDTUL)

5.1.6.4 Critical Temperatures of Plastics

5.2 Part Information Checklist

5.2.1 Part Technical Specifications Checklist

5.2.2 Target Factor Value Checklist

5.3 Mold Information

5.3.1 Metals and Steels for Mold Construction

5.3.2 Runners

5.3.3 Cold Runner Design

5.3.4 Hot Runners

5.3.5 Torpedo and Cavity Isolation

5.3.6 Mold Cooling System Information

5.3.7 Venting Information

5.3.8 Draft Angles

5.4 Summary of Required Information

6 Necessary Equipment for Advanced Injection Molding

6.1 Importance of Technical Equipment

6.2 Technical Equipment for Injection Molding and the Application of Scientific Injection Molding

6.2.1 Raw Material, Pellets, Moisture Meter or Moisture Analyzer

6.2.2 Temperature Probe

6.2.3 Thermal Infrared Camera

6.2.4 Balance

6.2.5 Micrometer Caliper Gauge

6.2.6 Shore A, Shore D Durometer

6.2.7 Microscope

6.2.8 Surface Tension Measurement Inks

6.2.9 Polarized Lenses

6.2.10 Adjustable Magnifying Glasses

6.2.11 Gauges, Calibrated Rods of Different Diameters

6.2.12 Melt Flow Index Tester

6.2.13 Miscellaneous Equipment

7 Tools for Scientific Injection Molding

7.1 Preliminary Studies and Calculations

7.1.1 Estimation of the Theoretical Clamping Force Required

7.1.2 Screw Rotation, Maximum RPM and Peripheral Screw Speed

7.1.3 Metering Stroke or Volume Calculation

7.1.4 Theoretical Cooling Time

7.2 Scientific Injection Molding Tools for Defining the Injection Molding Process

7.2.1 Viscosity Curve Test or In-Mold Rheology Test

7.2.1.1 Plastic Behavior

7.2.1.2 Viscosity Curve (or In-Mold Rheology) Test

7.2.1.3 Relative Viscosity or In-Mold Rheology Test: Injection Machine Configuration

7.2.1.4 Influence of Melt Temperature on the Study

7.2.2 Injection-Speed Linearity Test

7.2.3 Mold Filling Balance Study

7.2.3.1 Filling Balance Study: Injection Machine Configuration

7.2.3.2 Spiral Effect

7.2.4 Optimal Injection Speed Selection

7.2.5 Mold Filling Study

7.2.5.1 Mold Filling Study: Injection Machine Configuration

7.2.5.2 Mold-Filling Study Procedure

7.2.6 Analysis of Injection Pressure Losses along the Filling System

7.2.7 Delta P Determination and Study

7.2.8 Gate Sealing Study

7.2.8.1 Cavity Filling Analogy

7.2.8.2 Pack and Hold Stage

7.2.8.3 Gate Sealing Time

7.2.8.4 Gate Sealing Study: Injection Machine Configuration

7.2.8.5 Molding with an Open or Sealed Gate?

7.2.8.6 What if the Part Weight does Not Stop Increasing?

7.2.8.7 What about Hot Runners or Valve Gate Nozzles?

7.2.9 Process Window Determination (for the Holding Pressure Phase)

7.2.9.1 Process Window Study: Injection Machine Configuration

7.2.9.2 Process Window Study: Steps

7.3 Further Scientific Molding Tools or Studies for Checking and Improving the Injection Molding Process

7.3.1 Shear Rate at the Gate Study

7.3.2 Cooling System Study

7.3.3 Cooling Time Study

7.3.4 Study of Material Residence Time in the Injection Unit

7.3.5 Filling Time Repeatability Study

7.3.6 Screw Tip or Check Ring Valve Sealing Study

7.3.6.1 Dynamic Test Study

7.3.6.2 Static Test Study

7.3.6.3 What about Hot Runners?

7.4 Scientific Injection Molding Tools Application Diagram

7.4.1 Logical Sequence of Application

7.4.1.1 Preliminary Studies and Calculations

7.4.1.2 Tools for Defining the Injection Molding Process

7.4.1.3 Further Tools for Checking and Improving the Injection Molding Process

7.4.2 Logical Sequence of Application Diagrams

7.4.2.1 Preliminary Studies and Calculations

7.4.2.2 Tools for Defining the Injection Molding Process

7.4.2.3 Further Tools for Checking and Improving the Injection Molding Process

8 Top Ten Key Parameters in the Definition of the Injection Molding Process

8.1 Injection Speed

8.2 Melt Temperature

8.2.1 Influence of the Melt Temperature

8.2.2 Residence Time

8.3 Peripheral Screw Speed

8.4 Back Pressure

8.5 Injection Pressure

8.6 Switchover Point

8.7 Holding Pressure

8.7.1 Defining the Holding Pressure Time

8.7.2 Sealed or Open Gate?

8.8 Mold Temperature

8.9 Metering

8.10 Cushion

8.11 Other Key Aspects

8.11.1 Melt Preparation

8.11.1.1 Throat and Tracking Temperature

8.11.1.2 Decompression Stroke and Speed

8.11.1.3 Back Pressure

8.11.2 Machine Input Settings and Process Outputs

8.11.2.1 Parameter Data Sheets

8.11.2.2 Process Outputs

8.11.3 Process Tolerances

9 Process Portability, DOE (Design of Experiments), Mold Qualification and Process Validation

9.1 Process Portability

9.1.1 Portability

9.1.1.1 The Specific Units

9.1.1.2 The Essential.

Outputs

9.1.1.3 Important Process Inputs or Settings

9.1.2 Portability of Injection Speed Profile Switchover Points

9.1.3 Portability of Injection Pressures

9.1.3.1 Why is it Important to Know the Intensification Ratio?

9.1.3.2 Hydraulic Pressure to Specific Pressure Conversions

9.1.4 Process Portability Format and Checklist

9.2 Introduction to DOE (Design of Experiments)

9.2.1 Factors

9.2.2 Responses

9.2.3 Levels

9.2.4 Number of Experiments

9.2.5 Experiment Matrix

9.2.6 Injection Molding Factors or Parameters

9.2.7 Levels for Each Factor Selected

9.2.7.1 Melt Temperature

9.2.7.2 Injection Speed (Filling Time)

9.2.7.3 Packing and Holding Pressure

9.2.7.4 Holding Pressure Time

9.2.7.5 Mold Temperature

9.2.7.6 Cooling Time

9.2.8 Example of Experiment Matrix

9.3 Consistent and Robust Process through Experimentation and Testing

9.4 Scientific Process Flowchart for Mold Qualification and Process Validation

10 Melt Preparation

10.1 Parameters that Influence Melt Quality

10.2 Barrel Temperature Profile

10.3 Throat Temperature

10.4 Peripheral Screw Speed

10.5 Back Pressure

10.5.1 Effects of Back Pressure

10.5.2 Optimal Back Pressure Test

10.6 Decompression or Suction

11 Process Variability, Self-Adaptation, and Corrections

11.1 The Plastic Injection Process, Self-Adaptation to the Process Variability

11.1.1 Mold Filling in the Dynamic Injection Phase

11.1.2 The Filling, Packing and Holding Phase

11.2 Deviations from the Original Process Checks and Corrections

11.2.1 Checks To Be Carried Out in the Dynamic Filling Phase

11.2.2 Checks To Be Carried Out during the Holding Pressure Phase

11.2.3 Differences to Check with Cavity Pressure Sensors

11.2.4 Scientific Troubleshooter

11.2.5 Steps for Analyzing Deviations in the Injection Molding Process

12 Data To Be Collected for the Calculation and Performance ...

12.1 Data To Be Collected for Developing the Preliminary Studies and Calculations

12.2 Data To Be Collected for the Tests and Studies on the Reliability and Performance of Injection Molding Machines

12.3 Data To Be Collected for Scientific Injection Molding Methodology Tests and Studies

12.4 Data To Be Collected for the Tests and Studies of Further Scientific Molding Tools or Checking and Improving the Injection Molding Process

12.5 Data To Be Collected for Process Portability Tests and Studies

12.6 General Table for Injection Molding Tool Selection According to Different Objectives and Situations

13 Reference Data Tables

13.1 Maximum Residence Time

13.2 Usual Mold Temperatures

13.3 Shrinkage

13.4 Drying Conditions

13.5 Maximum Allowed Moisture Data

13.6 Recommended Depth of Venting Channels

13.7 Mold and Melt Temperatures, Shear, Etc.

13.8 Maximum Peripheral Speeds

13.9 Density, Melt and Room Temperature

Bibliography

Glossary

Index

Blank Page.

Notes:

Description based on publisher supplied metadata and other sources.

ISBN:

1-56990-942-3

OCLC:

1525620318