Cargando…
Handbook of molded part shrinkage and warpage /
How easy life would be if only moldings were the same size and shape as the mold. But they never are, as molders, toolmakers, designers and end users know only too well. Shrinkage means that the size is always different; warpage often changes the shape too. The effects are worse for some plastics th...
| Clasificación: | Libro Electrónico |
|---|---|
| Autor principal: | |
| Formato: | Electrónico eBook |
| Idioma: | Inglés |
| Publicado: |
Waltham, Mass. :
William Andrew,
2013.
|
| Edición: | 2nd ed. |
| Colección: | PDL handbook series.
|
| Temas: | |
| Acceso en línea: | Texto completo |
Tabla de Contenidos:
- Front Cover; Handbook of Molded Part Shrinkage and Warpage; Copyright; Contents; Preface; Acknowledgments; 1
- Introduction to Injection Molding; 1.1 Introduction to Plastics; 1.2 Interactivity Basics; 1.3 Thermal Principles Governing Injection Molding; References; 2
- Shrinkage and Warpage; 2.1 In-Mold Shrinkage; 2.2 Warpage; 2.3 Postmold Shrinkage; References; 3
- Causes of Molded-Part Variation: Part Design; 3.1 Wall Thickness; 3.2 Ribs; 3.3 Bosses; 3.4 Example of Proper Part Design; 3.5 Other Design Considerations; References; 4
- Causes of Molded-Part Variation: Material.
- 4.1 Amorphous and Semicrystalline Resins4.2 Effects of Fillers, Reinforcements, Pigments, Time, and Stress; 4.3 Shrinkage Predictions: Using PVT Relationships; References; 5
- Causes of Molded-Part Variation: Mold Design; 5.1 Cavity Dimensions and Design Factors; 5.2 Gate Types; 5.3 Gate Location; 5.4 Gate Size; 5.5 Gate Design Systems; 5.6 Runner Design; 5.7 Mold Cooling Design; 5.8 Mold Construction Materials; 5.9 Prototype Molding with Stereolithography or Similar Type Molds; 5.10 Pitfalls to Avoid; References; 6
- Causes of Molded Part Variation: Processing; 6.1 Molding Conditions.
- 6.2 Injection Melt Temperature6.3 Injection Rate and Pressure; 6.4 Holding Pressure and Time; 6.5 Mold Temperature; 6.6 Demolding Temperature; 6.7 Molded-In Stresses; 6.8 Other Molding Processes; References; 7
- Factors Affecting Postmold Shrinkage and Warpage; 7.1 Effects of Temperature on Dimensions; 7.2 Effects of Moisture on Dimensions; 7.3 Creep; References; 8
- Controlling Mold and Postmold Shrinkage and Warpage; 8.1 Finding the Cause; 8.2 Processing Considerations; 8.3 Material Considerations; 8.4 Tooling Considerations; 8.5 Part Geometry; 8.6 Controlling Warpage; References.
- 9
- Computer-Aided Analysis9.1 Capabilities of CAA; 9.2 Limitations of CAA; 9.3 Selecting a CAA Program; 9.4 Customer Requirements; 9.5 Management Tools; 9.6 Filling Analysis; 9.7 Packing and Holding Simulation; 9.8 Shrinkage/Warpage Simulation; 9.9 Cooling Analysis; 9.10 Costs; 9.11 Conclusions; References; 10
- Case Studies; 10.1 Unexpected Housing Shrink; 10.2 Changing Materials Triggers Warpage; 10.3 Creep in a Water Heater Stand; 10.4 Oversize Part Injection-Molding Alkyd Thermoset; 10.5 Inadequate Baby Dish Mold; 10.6 Gas Entrapment in Baby Dish Mold; 10.7 Warpage in a Molded Spool.
- 10.8 Daisy-Wheel Breakage10.9 PVC Part-Flashing Problems; 10.10 Polycarbonate Switch Failure; 10.11 Square Poker-Chip Tray: Inadequate Shot Size; 10.12 Problem Ejecting Square Poker Chips; 10.13 Military Cup Material "Shrinkage"; 10.14 Core-Deflection Problems; 10.15 Elevator Gib Warpage; 10.16 Sucker-Rod Guide Brittleness; 10.17 Bottle-Cap Thread Distortion; 10.18 Plastic Post Creep; 10.19 Excessive Shrinkage of Glass-Filled Nylon; 10.20 Preventing Warpage in Thin Molded Lids; 10.21 A Printed Circuit Board That Did Not Work; 10.22 A Cup with a Handle that Won't Fill.