Shop Talk: Injection Mold Venting Strategies
- Let us talk about mold venting. Getting it right matters whether you are 3D printing or CNC machining your molds — trapped air means bubbles and ruined parts.
- When designing mold vents, think about where the air needs to flow, not just the plastic. And if your mold has detailed features like paddle tails or fins, flip it upside down to help the air escape more easily.
- Our go-to venting strategy is a small offset all the way around the mold — a mini escape route for the air. Set the depth to match your process, whether you are 3D printing or CNC machining.
- Next, add extra venting channels to guide the air out. Watch for areas that might seal up too tight, and make sure the main vent is big enough to handle all the air leaving the mold.
- One last thing: with a multi-cavity mold, keep each cavity's venting separate so air from one cavity cannot sneak into another. We have a video with more mold-making tips below — check it out!
Watch the full breakdown video here: