1.

Record Nr.

UNINA9911004748403321

Autore

Fischer Jerry M

Titolo

Handbook of molded part shrinkage and warpage / / Jerry M. Fischer

Pubbl/distr/stampa

Waltham, Mass., : William Andrew, 2013

ISBN

1-4557-3057-2

1-283-85408-2

Edizione

[2nd ed.]

Descrizione fisica

1 online resource (289 p.)

Collana

PDL handbook series

Disciplina

668.4/12

668.412

Soggetti

Plastics - Molding

Lingua di pubblicazione

Inglese

Formato

Materiale a stampa

Livello bibliografico

Monografia

Note generali

Description based upon print version of record.

Nota di bibliografia

Includes bibliographical references and index.

Nota di contenuto

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

10.23 Leaking Hot Runner Mold

Sommario/riassunto

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 than others. Why is that? What can you do about it? The Handbook of Molded Part Shrinkage and Warpage is the first and only book to deal specifically with this fundamental problem. Jerry Fischer's Handbook explains in plain terms why moldings shrink and warp, shows how additives and reinforcements