Proper vents prevent "dieseling" (burn marks) caused by compressed air trapped in the cavity. 5. Radii and Fillets Sharp corners are the enemy of structural integrity.
: Shallow depressions on the surface of an otherwise flat plastic part.
of the thickness of the main wall to prevent sink marks on the exterior surface. injection mold design guide
The sprue is the primary entry point into the mold. It must have a draft angle of at least 2° to 3° to ensure it pulls out cleanly during ejection. The sprue diameter must be slightly larger than the machine nozzle orifice to prevent backflow. Runner Systems
: Connect different thicknesses with a chamfer or a radius step. The length of the transition zone should be at least three times the difference in thickness ( ) to ensure smooth plastic flow and prevent air entrapment. 2. Draft Angles and Demolding Proper vents prevent "dieseling" (burn marks) caused by
The plastic solidifies inside the temperature-controlled mold.
What are you using? (e.g., ABS, Nylon, Polycarbonate) Is this for high-volume production or prototyping ? Do you need advice on undercuts and lifters ? : Shallow depressions on the surface of an
Draft angles are tapers applied to the vertical faces of a part. Without a draft angle, the shrinking plastic will grip the mold core tightly, creating immense friction during ejection. This results in drag marks, part deformation, or complete ejection failure.
Cooling accounts for roughly 50% to 70% of the total injection molding cycle time. An optimized cooling system drastically improves throughput and part stability.
If you want, I can:
Sharp corners are stress concentrators. In a mold, sharp internal corners cause the steel to crack over time.