During the injection molding process of plastic products, shrinkage is often encountered, mainly due to uneven wall thickness of the product. Over-thick areas are prone to shrinkage, and due to insufficient glue or excessive resistance, the molten glue cannot fully fill the mold cavity.
Solution to concave injection molding products: Increase injection pressure, increase feeding stroke, increase injection time, limit the flow of all molten adhesive into the nearest sprue gate to allow it to flow into other gates, increase injection speed, increase gate size, reduce material pipe temperature, control the overheated part of the mold, cool the mold or immediately immerse the product in water or extend the cooling time.