Mold Flow Analysis Basics — Simulation for Injection Molding

Introduction to mold flow simulation: filling analysis, cooling analysis, warpage prediction. How to use CAE to optimize injection molds.

What Is Mold Flow Analysis?

Mold flow analysis uses CAE software to simulate the injection molding process before cutting steel. It predicts how molten plastic fills, cools, and solidifies.

Key Analysis Types

1. Filling Analysis

Simulates melt front advancement. Reveals flow hesitation, weld lines, air traps, short shot risk. Optimizes gate location and injection speed.

2. Packing Analysis

Simulates the holding phase. Predicts sink marks, shrinkage, required pressure. Optimizes hold pressure and time.

3. Cooling Analysis

Cooling = ~70% of cycle time. Predicts cooling time, temperature distribution, hot spots. Good cooling design shortens cycles.

4. Warpage Analysis

Predicts final part shape after ejection. Warpage from differential shrinkage, non-uniform cooling, fiber orientation.

Common Software

• Autodesk Moldflow — Industry standard
• Moldex3D — True 3D solver, better for thick parts
• SIGMASOFT — Virtual molding without mesh simplification

When to Use

• New mold design validation — catch problems before cutting steel
• Existing mold troubleshooting — identify defect root causes
• Process optimization — find optimal processing window