Before detailing features, understand the three golden rules:
A mold is a precision tool made of several plates and components. injection mold design guide
Injection molding is the undisputed king of high-volume plastic part production. It allows manufacturers to create complex geometries with tight tolerances at a remarkably low cost per unit. However, the difference between a part that pops perfectly out of the mold every 30 seconds and one that warps, sinks, or cracks is entirely determined before the steel is cut. The Ultimate Injection Mold Design Guide 1
| Requirement | Why it matters | |-------------|----------------| | Uniform wall thickness (0.5–4 mm typical) | Prevents sink, warpage, and fill imbalances | | Draft angle – 0.5° to 2° (per side) | Allows part release without drag marks | | Radii at corners – 0.25–0.5 × wall thickness | Reduces stress concentration and improves flow | | Nominal wall progression – gradual changes only | Avoids flow hesitation and freeze-off | Finish choices: Polished, fine, matte, or textured
The solution was a “fan gate”—wide and thin—spreading the flow like a delta. The pressure dropped, the flow slowed, and the lens came out crystal clear.