Injection Mold Design Guide !!exclusive!! Access

. This is structured to be highly scannable for engineers, product designers, and students. Comprehensive Guide to Injection Mold Design 1. Introduction to Injection Molding

Rule of thumb: You need enough ejection force to overcome the shrinkage friction (approx. 10% of clamping force). Increase pin diameter if the plastic is soft (TPU, silicone).

11. Mold Materials and Treatment

• Common steels: P20 (pre-hardened tooling steel for prototypes/low volume), H13 (hot-work steel for high-temp, high-volume), S7, and stainless steels for corrosive environments.
• Hardness and coatings: Hardened inserts for wear resistance; nitriding, PVD/CVD coatings or chrome plating for abrasion resistance and release.
• Maintenance: Plan for easy access to wear areas, replaceable inserts, and vents for long-term serviceability.

3. Parting Line and Mold Split

• Locate parting line: Place along least-visible or least-critical surfaces when possible. Keep parting line straight for simpler tooling.
• Undercuts: Minimize. If necessary, use side-actions, lifters, or collapsible cores. Consider slide mechanisms for complex features.
• Ejector pin placement: Place on non-critical surfaces, thick sections, or bosses; ensure even ejection to avoid part distortion.