1;Foreword;62;Preface;83;Acknowledgements;104;Contents;125;1 Polymer Flow Behavior in Injection Molds;225.1;1.1 Phases of Injection Molding;225.1.1;1.1.1 How Plastic Fills a Mold;225.1.2;1.1.2 The Filling Phase;245.1.3;1.1.3 The Pressurization Phase;275.1.4;1.1.4 The Compensation Phase;275.2;1.2 How Do Plastics Flow?;285.2.1;1.2.1 Material Behavior;285.2.2;1.2.2 Deformation;295.2.3;1.2.3 Viscoelastic Behavior;295.2.4;1.2.4 Melt Shear Viscosity;305.2.5;1.2.5 Newtonian Fluid vs. Non-Newtonian Fluid;315.2.6;1.2.6 Shear-thinning Behavior;315.2.7;1.2.7 Shear Rate Distribution;325.2.8;1.2.8 Pressure-driven Flow;325.2.9;1.2.9 Pressure Gradient and Injection Times;345.2.10;1.2.10 Melt Flow Length;345.2.11;1.2.11 Injection Pressure vs. Fill Time;345.2.12;1.2.12 Flow Instability;366;2 Molding Conditions and Injection Pressure;386.1;2.1 Injection-pressure Overview;386.1.1;2.1.1 Pressure Drives the Flow Front;396.2;2.2 Factors Influencing Injection-pressure Requirements;396.3;2.3 Equations;416.3.1;2.3.1 Circular Channel Flow;416.3.2;2.3.2 Strip Channel Flow;416.4;2.4 Effect of Molding Conditions;426.4.1;2.4.1 Part Quality;426.4.2;2.4.2 Melt Temperature;436.4.3;2.4.3 Mold Temperature;436.4.4;2.4.4 Fill Time;446.4.5;2.4.5 Shear Stress Variation;446.4.6;2.4.6 Packing Pressure and Time;456.4.7;2.4.7 Summary;466.4.8;2.4.8 Back Flow;476.5;2.5 Using Moldflow to Determine Optimum Molding Conditions;476.5.1;2.5.1 Part;486.5.2;2.5.2 Molding Window Size;486.5.3;2.5.3 Injection Pressure;496.5.4;2.5.4 Flow Front Temperature;506.5.5;2.5.5 Cooling Time;516.5.6;2.5.6 Summary;527;3 Filling Pattern;547.1;3.1 Filling Pattern Overview;547.1.1;3.1.1 What Is the Filling Pattern?;547.2;3.2 Flow in Complex Molds;557.2.1;3.2.1 Overpack;557.2.2;3.2.2 Racetrack Effect;567.2.3;3.2.3 Varying Injection Rate;567.2.4;3.2.4 Underflow Effect;577.2.5;3.2.5 Hesitation Effect;587.2.6;3.2.6 Weld Lines;597.2.7;3.2.7 Meld Lines;597.2.8;3.2.8 Sink Marks;597.2.9;3.2.9 Multidirectional Flow;607.2.10;3.2.10 Unstable Flow;617.2.11;3.2.11 Simple Flow Pattern;627.3;3.3 Flow-front Velocity and Flow-front Area;627.3.1;3.3.1 What are FFV and FFA?;627.3.2;3.3.2 Flow-front Velocity Influences Filling Pattern;627.3.3;3.3.3 Equation;637.4;3.4 Using Moldflow to Determine the Filling Pattern;647.4.1;3.4.1 Computer Simulation Can Eliminate Molding Trials;647.4.2;3.4.2 Using a Flow Analysis;647.5;3.5 Using Moldflow to Achieve Constant FFV;657.5.1;3.5.1 Controlling the FFV Through Ram Speed;658;4 Moldflow Design Principles;688.1;4.1 Product Design and Moldflow;688.2;4.2 Sequence of Analysis;688.2.1;4.2.1 Part Filling Optimization;698.2.2;4.2.2 Molding Conditions;698.2.3;4.2.3 Runner Design;698.2.4;4.2.4 Cooling Optimization;708.2.5;4.2.5 Packing Optimization;708.2.6;4.2.6 Warpage Optimization;708.3;4.3 Moldflow Flow Concepts;708.3.1;4.3.1 Unidirectional and Controlled Flow Pattern;718.3.2;4.3.2 Flow Balancing;728.3.3;4.3.3 Constant Pressure Gradient;738.3.4;4.3.4 Maximum Shear Stress;748.3.5;4.3.5 Uniform Cooling;758.3.6;4.3.6 Positioning Weld and Meld Lines;768.3.7;4.3.7 Avoid Hesitation Effects;768.3.8;4.3.8 Avoid Underflow;768.3.9;4.3.9 Balancing with Flow Leaders and Flow Deflectors;788.3.10;4.3.10 Controlled Frictional Heat;798.3.11;4.3.11 Thermal Shutoff of Runners;798.3.12;4.3.12 Acceptable Runner/Cavity Ratio;809;5 Meshes Used In Moldflow Analyses;829.1;5.1 Mesh Types Used by Moldflow;829.1.1;5.1.1 Finite Elements Used in Moldflow;829.1.2;5.1.2 Mesh Types;839.1.3;5.1.3 Solver Assumptions;849.2;5.2 Mesh Requirements;859.2.1;5.2.1 Mesh Density Considerations;859.2.2;5.2.2 Part Details;889.3;5.3 Geometry Creation;899.4;5.4 Importing Geometry;909.5;5.5 Using Different Mesh Types;909.5.1;5.5.1 Door Panel;909.5.2;5.5.2 Manifold;9110;6 Product Design;9210.1;6.1 Material Properties for Product Design;9210.1.1;6.1.1 Plastics Are Sensitive to Operating Conditions;9210.1.2;6.1.2 Stress-Strain