The primary advantages of injection molding are its unparalleled speed, extremely low cost per part at high volumes, and exceptional repeatability. Its main disadvantages are the significant upfront tooling cost and the long lead time required to design and manufacture the custom steel mold. This makes the process highly inflexible and cost-prohibitive for low-volume production or prototypes.
The most effective way to reduce injection molding costs is during the part design phase. Simplifying geometry, eliminating undercuts, applying uniform wall thickness, and relaxing tolerances have the biggest impact on the primary cost driver: the complex steel mold. Strategic material and tooling choices can further reduce both upfront and long-term expenses.
Think of an injection mold not as a simple block of steel, but as a complex, custom-built 3D puzzle. Each precisely engineered piece has a critical job to do. For designers and engineers, understanding how this puzzle fits together is the secret to creating plastic parts that are not only beautiful but also highly manufacturable and cost-effective.