Table of Contents. Norman C. Lee. Blow Molding Design Guide ISBN: For further information and order see

Transcription

1 Table of Contents Norman C. Lee Blow Molding Design Guide ISBN: For further information and order see or contact your bookseller. Carl Hanser Verlag, München

2 Contents Preface... V 1 The Basics of Blow Molding Definition The Basic Process History Summary of Development Design Parameters Benefits, Disadvantages, and Comparisons The Design Process An Organized Approach Introduction Main Structure Six Perspectives on the New Manufacturing Enterprise Product Design and Development Management System (PD2MS) PD2MS Process Management Tracking Systems Commitment of Resources Concurrent Engineering Conclusion Basic Blow Molding Part Design Basic Design Considerations Size Variations Understanding Hollow Structures Draft of Part Increase Draft as Blow Ratio Increases Guidelines for Radii Corner and Edge Rounding Chamfers Molded-In Geometric Configuration Flanges and Tack-Offs Threaded Parts Attachments and Auxiliary Units Conclusion Design for Bottles Blow Molding Process Basic Shapes Simplified Assumptions About Parison Expansion Bottle Design Concepts for Extrusion Blow Molding of HDPE... 38

3 VIII Contents Ribs: Do Not Always Stiffen Cross-Sections Bottle Neck, Threads, and Openings Container Volume Container Volume Measurements Standards Machine Line Mold Volume Correction Source of Error in Volume Correction Package Dairy Mold Volume Correction Production Conditions Annealing Tunnel Conclusion Industrial and Structural Part Design The Blow Molding Process Preferred Process Hollow Parts Resin/Fiberglass Lay-up and Structural Foam Molding Foam-Filled Kinetic Energy Design Engineering Molded-In Insert of Components Interlocking Systems Snap Fits Multiple/Combination Cavities Container Configuration Design Flat Sides Lip Nesting and Stacking Cutting Containers Apart Double Walled Cases Conclusion Computer Aided Design and Engineering Analysis Performance Criteria Computer Software Simulation Traditional Approach Simulation-Based Approach Reducing Parison Thickness Fluid Flow Finite Element Simulation Modeling Simulation Prediction Example Polymer Inflation and Thinning Analysis Effects of Geometry Understanding Wall Thickness Examples: Using Normalized Thickness Curves Conclusion... 79

4 Contents IX 7 Polymers and Plastic Materials Basic Polymer Chemistry Structure of Matter Polymers Homopolymers, Copolymers, and Terpolymers Thermoplastic and Thermoset Polymers Amorphous and Crystalline Fundamental Properties Average Molecular Weight Chain Length Linking Morphology Additives, Fillers, and Reinforcing Agents Physical Properties Specific Gravity Melt Flow Rate (Melt Index) Moisture Hardness Tensile Strength and Properties Creep Basic Polymer Parameters and Their Effect on Product Properties Polymer Characteristics Relevant for Blow Molding High-Density Polyethylene (HDPE) Acrylonitrile-Butadiene-Styrene (ABS) Polycarbonate (PC) Polypropylene (PP) Polyphenylene Oxide (PPO) Polyethylene Terephthalate (PET) Coloring Plastic Materials Regrind Post-Consumer and Industrial Recycled Materials The Blow Molding Process Extrusion Blow Molding Understanding the Extruder Blow Molding Technique Continuous Extrusion Shuttle System Rising Mold Rotary Wheel Intermittent Extrusion Reciprocating Screw Ram Accumulator Coextrusion Introduction to Head Tooling Converging Diverging

5 X Contents Tooling Choices Part Weight and Wall Thickness Adjustment Parison Programming Die Ovalization Blow Pins/Needles Needles Pins/Needles Injection Blow Molding Injection Blow Molding Process The Injection Blow Molding Machine Stretch Blow Molding New Applications of Blow Molding Technology Coextrusion Blow Molding of Large Parts Reasons for Coextrusion Typical Structures Intermittent and Continuous Extrusion Blow Molding Methods of Continuous Coextrusion Blow Molding Three-Dimensional Blow Molding Mold Inclining System and Computer Controlled Mold Oscillating Device The X Y Process Formed Parts Features of the X Y Machine The Three-Dimensional Technology of Suction Blow Molding Three-Dimensionally Curved Blow Moldings Hard-Soft-Hard and Soft-Hard-Soft Technology Axial Coextrusion Preferred Material Combinations Long-Glass-Fiber-Reinforced Blow Molding Blow Molding Foam Technology Advantages Blow Foam Technology Products Conclusion Understanding the Mold Main Characteristic of Mold Halves Mold Materials Cast Aluminum and Beryllium Aluminum Plate Steel Importance of Fast Mold Cooling Cooling Cooling Lines Pinch-Off Areas Blowing Pin Internal Cooling

6 Contents XI 10.4 Cutting and Welding Parison (Pinch-Off) Pinch-Off Section Uniform Weld Lines High-Quality, Undamaged Mold Cavity Finish Effects of Air and Moisture Trapped in the Mold Venting Injection of the Blowing Air Ejection of the Part from the Mold Bottle Molds Neck Ring and Blow Pin Design Dome Systems Prefinished System Unusal Problems Injection Blow Molds Parison (Preform) Mold Neck Ring Insert The Core Rod Assembly Materials for Parison Cavity and Core Rods Design Details of the Blow Mold Cavity Vents Neck Ring Insert Bottom Plug Insert Die Sets Injection Blow Mold Tooling Summary Conclusion Computer Aided Design and Engineering for Mold Making Advantages Systems and Methods Analytical Personal Computer Minicomputer Network Station Approach Utilizing CAD/CAM in a Mold Making Organization Engineering Activities Manufacturing Activities Decoration of Blow Molded Products Introduction Surface Treatment Surface Treatment Methods Flame Treatment Corona Discharge Washing with Water-Based Chemicals Solvent Cleaning and Etching Additives Compounded into Resins Spray Painting Air Atomization and Airless Sprays Masking

7 XII Contents Vapor Degreasing Mechanical Abrasion Sanding Chemical Etching Labels Label Application Screen Printing Screen Printers Pad Printing Pad Equipment Hot Stamping Hot Stamping Foils Decals In-Mold Labeling In-Mold Labeling Equipment The In-Mold Labeling Process In-Mold Labeling Molds Cycle Times Aesthetics Conclusion Finishing Layout the Entire Process, Step by Step Product Design Mold Engineering Trimming and De-Flashing Removing Domes and Other Sections The Cutting Machine Round Parts versus Parts with Corners Cost Estimating Introduction Typical Cost Sheet Cost Conclusion Cost Estimating Calculations Part Requirements Cooling of the Part Throughput of the Machine Post-Molding Operations Setup and Purging of Material from Previous Product Run Appendix A Troubleshooting A.1 Detailed Failure Analysis Overview and Summary A.1.1 Rocker Bottoms and Oval Necks A.1.2 Defects Within the Blown Wall A Bubbles A Cold Spots A Thinning

8 Contents XIII A Tearing A Cutting A Indented Parting Lines A.1.3 Poor Bottle Surface A.1.4 Curtaining and Webbing A.1.5 Blowouts A.1.6 Parison Curl, Stringing, Hooking, Sag, and Length Consistency A Parison Curl A Parison Stringing A Parison Hooking A Parison Sag A Parison Length Inconsistency A.1.7 Foreign Matter in the Melt A Look for Exterior Sources of Contamination First A Degraded Resin Many Sources A Culprit Man or Machine? A.1.8 Die Lines or Streaking in the Parison A.1.9 Shrinkage A.1.10 Causes of Stress Cracking A Environmental Stress Cracking A Solvent Stress Cracking A Mechanical Stress Cracking A.1.11 Heat Too Much or Too Little and What to Do About It A Instrument Recalibration A.1.12 Surging A.1.13 Sharkskin A.1.14 Screw Wear Affects Performance A Inspection Rollers A Diameters A Depths A Concentricity and Straightness A Hardness A Finish and Coating Thickness A Screw Manufacturing Tolerances A.1.15 Barrel Inspection A Inside Diameters A Straightness and Concentricity A Barrel Hardness A Barrel Specifications A.1.16 Detecting Container Leakage Subject Index