Venting Design for Injection Mold Parting Surfaces
Venting design on the parting surface of injection molds is a crucial aspect of ensuring product quality. If air and volatile gases within the mold cavity are not effectively expelled, defects such as voids, burn marks, and surface flaws may occur. Proper venting design can significantly improve the appearance and performance of products while enhancing production efficiency.
Functions of Parting Surface Venting
1. Avoid Gas Retention
Expels air from the mold cavity to prevent gas compression under high temperature and pressure, which can cause voids or burn marks in the product.
2. Improve Filling Performance
Reduces the resistance to melt flow, ensuring the material fills the mold cavity uniformly.
3. Enhance Product Quality
Venting reduces defects like warping, shrinkage, and surface imperfections.
Common Forms of Parting Surface Venting
1. Natural Gap Venting
Features: Achieved through tiny gaps in the parting surface.
Application: Suitable for simple products, but venting efficiency is relatively low.
Gap Size: Should be controlled between 0.01mm and 0.03mm to prevent flash.
2. Venting Groove Venting
Features: Dedicated venting grooves are machined into the parting surface, offering higher efficiency.
Recommended Dimensions:
Depth: 0.02mm–0.05mm
Width: 3mm–5mm
Length: Typically extends to the outside of the mold
Application: Ideal for complex products or mold cavities requiring rapid venting.
3. Insert-Based Venting
Features: Utilizes gaps between removable inserts within the mold to facilitate venting.
Application: Suitable for molds with complex shapes or designs requiring multiple venting points.
