Handbook of Molded Part Shrinkage and Warpage


  • Jerry Fischer, Tools and Troubleshooting, Inc.
  • Jerry Fischer, Tools and Troubleshooting, Inc.

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.
View full description


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


Book information

  • Published: June 2003
  • ISBN: 978-1-884207-72-3


"This is a great book." - Injection Molding Magazine

Table of Contents

Pressure-Volume-Temperature (PVT) BehaviorRecrystallization and Stress ReliefMold Shrinkage (<24 hours)Post Mold Shrinkage (>24 hours)MaterialCrystalline vs. AmorphousAnisotropic BehaviorEffect of FillersEffect of PigmentsMoisture AbsorptionLow Warp MaterialsPart DesignGeometry & ThicknessSink MarksMold DesignGate Design and LocationRunner and Mold Cooling DesignPart EjectionProcessingMold and Injection TemperatureHolding Pressure and TimeInjection Speed and PressureMolded In StressAnnealing/Stress RelievingPost Mold FixturingFactors Affecting Post Mold ShrinkagePitfalls to AvoidGas Assist and Multi Component Molding OptionsComputerized Shrinkage and Warpage AnalysisHow Does It Work?Does It Work?How Much Does It Cost?How and When to Use ItShrinkage and Warpage in Specific ApplicationsMaterial Specific Data Collection of Hundreds of Graphs and TablesShrinkage versus:Wall Thickness and Part GeometryMold and Injection TemperaturesHolding and Injection PressuresTime at Various Temperature and HumiditiesFiller ContentPVT CurvesShrinkage Comparison for Thousands of GradesDiscussions on Mold Shrinkage, Post Mold Shrinkage and WarpageGlossaryIndex