Avoiding Air Bubbles
- Category: Tech Tips
Trapped air in a mixed polyurethane resin system can produce bubbles in the surface or wall of a cast part. To prevent the formation of voids, care must be taken during the mixing process so that air is not whipped into the polyurethane. Before the material is poured into the mold, it should be vacuum degassed. For thin-walled castings, the mold can be filled and cured under pressure.