Injection Mold Design Guide 🔖

As molten plastic shoots into the closed mold cavity, it violently displaces the air inside. If this air cannot escape, it compresses rapidly, heats up, and burns the plastic (known as "diesel effect" or burn marks).

As plastic fills the mold, trapped air must escape. Place shallow venting channels (0.01mm to 0.03mm deep) along the parting line and near the end of the fill paths. Insufficient venting causes compressed air to overheat, burning the plastic part. 5. Troubleshooting Common Mold Defects

Every polymer has a specific shrinkage rate: injection mold design guide

The Ultimate Injection Mold Design Guide: Principles, Best Practices, and Optimization

If you are currently developing an injection mold or looking to optimize a specific design, let me know the you plan to use, your target annual production volume , and whether the part has any internal or external undercuts . I can help you select the ideal gate style, cooling layout, or side-action mechanism for your project. Share public link As molten plastic shoots into the closed mold

If your mold is failing, diagnose via the geometry.

| Part weight | Runner diameter (round) | |-------------|-------------------------| | <10 g | 2–4 mm | | 10–100 g | 4–6 mm | | 100–500 g | 6–10 mm | | >500 g | 10–15 mm | Place shallow venting channels (0

Sharp internal corners lead to cracks; adding a radius distributes the load.

How the plastic enters and how the air leaves determines part quality.

: Pins leave faint circular impressions on the plastic. Keep these pins on the non-cosmetic interior (B-side) of the part. 6. Advanced Geometry: Undercuts and Actions

Use 3.0 to 5.0 degrees of draft where metal slides against metal to prevent tool wear. 3. Ribs, Bosses, and Corners