Film Processing Advances

Foreword

Contents

Contributors

Preface

1 Extruder and Screw Design for Film Processing

1.1?The Extrusion Process

1.2?Rate Calculation

1.3?Gels

1.4?Troubleshooting Extrusion Processes

1.4.1?Improper Shutdown of Processing Equipment

1.4.2?Gel Showers in a Cast Film Process

1.4.3?Unmixed Gels

1.4.4?Carbon Specks in a Film Product

1.4.5?Rate Limitation Due to a Worn Screw

2 Kinematics, Dynamics, Crystallization, and Thermal Characteristics and Their Relationship to Physical Properties of Blown Film

2.1?Abstract

2.2?Introduction

2.3?Real-Time Crystallization of the Blown Film Process

2.4?Experiments

2.5?Process Data Analysis

2.6?SALS Image Analysis

2.7?Nucleation with High-Density Polyethylene

2.8?Experiments

2.9?Results

2.10?Temperature Measurement and Heat Transfer from the Blown Film Bubble

2.11?Measuring Film Emissivity and Film Thickness

2.12?Film Average Bulk Temperature and Surface Temperature

2.13?Experimental Evaluation of the Bubble Heat Transfer Coefficient

2.14?Results and Discussion

2.15?Correlating of MD and TD Properties of Blown Film

3 Multilayer Die Design and Film Structures

3.1?Background

3.1.1?Materials

3.1.2?Film Structures

3.1.3?Equipment Producers

3.2?Basic Coextrusion Film Die Types

3.2.1?Manufacturing Method

3.2.2?Cast Die Types

3.2.3?Blown Film Die Types

3.3?Interfacial Instabilities

3.3.1?Merging Area, Wave Type of Interfacial Instabilities, and the TNSD Sign Stability Criterion

3.3.1.1?The Effect of Die Design on the Wave Type of Interfacial Instabilities

3.3.1.2?The Role of Extensional Viscosities

3.3.2?Die Exit Region, Zigzag Interfacial Instabilities, and the Role of Polymer Processing Aids

3.3.3?Development of Interfacial Instabilities in Cast Film and Film Blowing of LDPEs

3.4?Flow Analysis for Flat Spiral Die

4 Die Flow Analysis and Mathematical Modeling of Film Blowing

4.1?Introduction

4.2?Die Flow Analysis

4.3?Computer-Aided Die Design

4.4?Modeling of Bubble Forming

4.5?Effect of Viscoelasticity

4.6?Modeling of Bubble Cooling

4.7?Bubble Collapsing

4.8?Critique on Flow Analysis and Bubble Modeling

4.9?Concluding Remarks

5 T-die Film Casting

5.1?Introduction

5.2?Film Casting Process

5.3?Theoretical Analysis of Film Deformation under a Steady State

5.4?Deformation Behavior of T-die Casting

5.5?Draw Resonance

5.6?Film Breakage

5.7?Necking Phenomenon

5.8?Surface Roughness Caused by Shark Skin and Melt Fracture

5.9?Film Physical Properties

5.9.1 Influence of Process Conditions

5.9.2 Influence of Polymer Design

5.9.2.1 Branching and Properties of LLDPE

5.9.2.2 Impact Strength

5.9.2.3 Heat Seal Temperature

5.9.2.4 Blocking and Slippage

5.9.2.5 Transparency

5.9.2.6 Summary of Film Physical Properties

5.10? Bleeding of Additives in a Polypropylene Film

6 An Overview of Molten Polymer Drawing Instabilities

6.1?Introduction

6.2?Experiments

6.3?Modeling Strategy: Constant Width Cast Film Process

6.4?Cast Film Process

6.4.1?Influence of Cooling

6.4.2 Influence of the Neck-In Phenomenon

6.4.3?Validity of the Membrane Model: 2-D Transverse Simulation

6.4.4 Influence of Rheology

6.5?Fiber Spinning

6.6?Film Blowing

6.7?Conclusions

7 Biaxial Oriented Film Technology

7.1?Introduction

7.2?Biaxial Oriented Film Lines

7.2.1?Sequential Film Lines

7.2.1.1?Extrusion

7.2.1.2?Casting Machine

7.2.1.3?Machine Direction Orienter (MDO)

7.2.1.4?Transverse Direction Orienter (TDO)

7.2.1.5?Pull Roll Stand

7.2.1.6?Winder

7.2.2?Simultaneous Stretching Lines

7.3?Process Control

7.4?Development Environment for Biaxial Oriented Films

7.5?Market for Biaxial Oriented Films

8 Biaxially Oriented Tentering Film

8.1?Introduction

8.2?Tentering Process

8.3?Biaxially Oriented Tentering Machine

8.4?Theoretical and Experimental Analyses and Polymer Design for Biaxially Oriented Film

8.4.1?Cooling Process Analysis

8.4.2?Stretching Process Analysis

8.5?Visualization of Stretching Process

8.6?Film Physical Properties of Biaxially Oriented Film

8.7?Surface Roughness Control of Stretched Film

9 Structure Development in Uniaxial and Biaxial Film Stretching

9.1?Introduction

9.2?Equipment for In Situ Measurement of Optical Retardation

9.3?In Situ Measurement during Batch-Type Film Stretching Experiments

9.3.1?Variation of In-Plane Birefringence during Uniaxial Stretching and Relaxation Processes

9.3.2?Three-Dimensional Analysis of Birefringence Development in?Film Stretching

9.3.2.1?Uniaxial Elongation

9.3.2.2?Planar Elongation

9.3.2.3?Simultaneous Biaxial Elongation

9.3.3?Stress versus Birefringence Behavior

9.4?Analysis of Sequential Biaxial Elongation

9.4.1?Theoretical Prediction for Sequential Biaxial Elongation

9.4.2? Off-Line Analysis of Film Samples from the Sequential Biaxial?Stretching Process

9.4.2.1?Birefringence

9.4.2.2?WAXD Analysis

9.5? Intrinsic Birefringence for Various Orientation Modes

9.6?Concluding Remarks

10 Double Bubble Tubular Film Extrusion

10.1?Introduction

10.2?Double Bubble Tubular Machine

10.3?Theoretical Analysis of Double Bubble Tubular Film Process

10.3.1?Theoretical Analysis of Preheating Process and Stretching Process

10.3.2?Analysis of Stretching Stress

10.4?Bubble Deformation Behavior [16]

10.5?Film Properties

10.6?Comparison of Double Bubble Tubular Film (DBTF) and Laboratory Tenter Stretched Film (LTSF) [17]

10.6.1?Bubble Deformation Behavior and Stretching Stress

10.6.2?Comparison of LLDPE Film Properties of DBTF and LTSF

10.7?Material Design of Polyolefin for Double Bubble Tubular Film

10.7.1?Polyethylene [18]

10.7.2?Polypropylene [19]

10.8?Thickness Uniformity

10.9?High Performance Film Produced by Blend and Multilayer Stretching Process

10.10?Scale-Up Rule

10.11?Three Different Stretching Processes

10.12?Conclusions

11 Double Bubble Tubular Film Process and Its Application

11.1?Introduction

11.2?Physical Properties of Biaxial Oriented PA6 Film for Simultaneous Stretching and Sequential Processing

11.2.1?Stretching Process (Three Technical Methods)

11.2.2?Film Physical Properties

11.2.2.1?Impact Strength

11.2.2.2?Tensile Properties

11.2.2.3?Shrinkage Properties in Hot Water (Shrinkage Patterns)

11.2.2.4?Stress-Strain Curve Pattern

11.2.3?Wide-Angle X-ray Diffraction Pattern

11.2.4?Polarized Fluorescence

11.3?Easy-Tear Film of Biaxial Oriented PA6/MXD6 Blend by Double Bubble Tubular Film Process

11.3.1?Equipment and Materials

11.3.2?Blend Ratio (Dry Blending)

11.3.2.1?Stretchability

11.3.2.2?Physical Properties

11.3.2.3?Easy-Tearing Properties

11.3.2.4?Observation with TEM

11.3.2.5?Observation with SALS

11.3.2.6?Mechanism of Developed Property

11.3.2.7?Thickness Uniformity

11.3.3?Kneading Conditions (Premixing)

11.3.3.1?Stretchability (Melting Point of MXD6)

11.3.3.2?Physical Properties

11.3.3.3?Structure Analysis

11.4?Summary

12 Highly Transparent Polypropylene Sheets

12.1?Introduction

12.2?Influence of Screw Geometry on External Haze of Melted Web

12.2.1?Preliminary Extrusion Tests Using Typical and Simple Geometry Screw

12.2.2?Optimization of Screw Geometry

12.3?Influence of Shear Stress in Die on Internal Haze

12.4?Analysis of Contributing Factors to Production of Highly Transparent PP Extrusion Sheets

12.4.1?Influence of Isotacticity on Transparency

12.4.2?Influence of Molecular Weight Distribution on Transparency

12.4.3?Influence of Addition of Metallocene Linear Low Density Polyethylene on Transparency

12.5?Conclusion

Author Index

Subject Index