Handbook of Molded Part Shrinkage and Warpage

Pressure-Volume-Temperature (PVT) Behavior
Recrystallization and Stress Relief
Mold Shrinkage (<24 hours)
Post Mold Shrinkage (>24 hours)
Material
Crystalline vs. Amorphous
Anisotropic Behavior
Effect of Fillers
Effect of Pigments
Moisture Absorption
Low Warp Materials
Part Design
Geometry & Thickness
Sink Marks
Mold Design
Gate Design and Location
Runner and Mold Cooling Design
Part Ejection
Processing
Mold and Injection Temperature
Holding Pressure and Time
Injection Speed and Pressure
Molded In Stress
Annealing/Stress Relieving
Post Mold Fixturing
Factors Affecting Post Mold Shrinkage
Pitfalls to Avoid
Gas Assist and Multi Component Molding Options
Computerized Shrinkage and Warpage Analysis
How Does It Work?
Does It Work?
How Much Does It Cost?
How and When to Use It
Shrinkage and Warpage in Specific Applications
Material Specific Data Collection of Hundreds of Graphs and Tables
Shrinkage versus:
Wall Thickness and Part Geometry
Mold and Injection Temperatures
Holding and Injection Pressures
Time at Various Temperature and Humidities
Filler Content
PVT Curves
Shrinkage Comparison for Thousands of Grades
Discussions on Mold Shrinkage, Post Mold Shrinkage and Warpage
Glossary
Index

The handbook explains in plain terms why moldings shrink and warp, shows how additives and reinforcements change the picture, sets out the effect of molding process conditions, and tells why you never can have a single ""correct"" shrinkage value. But that's not all. The handbook shows how to alleviate the problem by careful design of the molded part and the mold and by proper material selection. It also examines computer-aided methods of forecasting shrinkage and warpage. And most important of all, the handbook gives you the data you need to work with.



This is the most complete collection of shrinkage data ever made and includes an extensive compilation of hard-to-find multi-point information on how processing, part design, mold design, material and post mold treatment affect the part's final dimensions. Manufacturers' figures for thousands of grades, along with an exhaustive search of magazines, journals, conference papers, books, web sites and brochures combine to make this a powerful resource.



A lot depends on a dimensionally correct molding. Quality, speed to market, profit margins for the molder and toolmaker, the efficiency of secondary and assembly operations, reputation; all these are on the line. The Mold Shrinkage and Warpage Handbook is the book for people who have to live with shrinkage and warpage. It is the only book for people who have to commit themselves.

Plastics engineers, technicians, and scientists in injection molding facilities.