Injection molding is the undisputed king of high-volume manufacturing. From automotive dashboards to medical syringes and smartphone cases, if a plastic part exists, chances are it was born from an injection mold. However, the difference between a part that is cheap, strong, and fast to produce versus one that is riddled with sink marks, warp, and long cycle times lies entirely in the design of the tool.
Size: A minimum font size of 20 points is recommended to ensure the plastic resin can flow into every part of the letter.
VII. Mold Venting System
Your material dictates steel type, vent depth, and surface finish.
4. Mold Components
| 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 |
: These are the channels that deliver material from the injection nozzle to the gates. Efficient runner design minimizes material waste and pressure drop. Ejection System : Once the part is cooled, mechanical ejector pins injection mold design guide
5. Design Guidelines for Parting Line and Ejection