Successful die design is critical for cost, quality, and extrudability:
- Wall Thickness: Maintain uniform thickness where possible. Avoid drastic changes. Respect minimum thickness rules.
- Hollows & Tongues: Design hollows to be as symmetrical as possible. Avoid long, thin “tongues” in the die, which are weak and prone to bending.
- Corner Radii: Use generous internal radii (fillets). Sharp corners create stress concentrations in the die and profile, and hinder metal flow.
- Tolerances: Specify only as tight as necessary. Tight tolerances increase die cost and part rejection rate.
- Extrusion Ratio: The ratio of the container area to the profile’s cross-sectional area. It affects pressure required and metal flow. Your extruder will advise on this.
- Symmetry: Symmetrical shapes extrude more easily and with less distortion than asymmetrical ones.