6 Ideas to Reduce Your Injection Molding Costs

Cut your injection molding costs without sacrificing quality.

Producing high-quality parts while keeping costs minimal is a tricky balancing act.

However, significant cost savings are attainable in injection molding with a strategic approach to design and material choices. In this article, we’ll delve into six ideas to achieve this.

What is Injection Molding?

Injection molding is a widely used manufacturing process in which molten material, typically plastic, is injected into a mold to produce parts in high volumes.

Thanks to its ability to produce complex shapes with great precision, injection molding thrives in the mass production of parts, ranging from simple toys to intricate components in the automotive and aerospace industries.

While the cost per part can be pretty low, especially once order quantities get to the thousands, the upfront costs can be high due to the tooling costs related to the mold. The best time to reduce costs is in the design phase.

Optimize Wall Thickness

One of the foundational principles in injection molding design is ensuring a uniform wall thickness. Doing this ensures even cooling, minimizes warping, and reduces material usage.

When parts cool unevenly, it can lead to internal stresses, sink marks, and other defects. By keeping walls uniform and as thin as feasible without compromising the part’s function, you can save on material costs and reduce the risk of defects.

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Minimize Undercuts

Sometimes, undercuts – such as holes, depressions, or protrusions – are essential for the part’s function or aesthetics.

Otherwise, it would be best if you eliminated undercuts. These complicate molding and require special mechanisms that drive up tooling costs. These mechanisms might include sliding parts or ejection pins to ensure the safe removal of the finished part.

By avoiding unnecessary undercuts or redesigning parts to eliminate them, molding becomes more streamlined and less expensive.

Use a Family Mold

The molds can lead to high tooling costs, so why not maximize resources with a family mold?

Family molds can be a cost-effective solution for producing multiple different parts in a single cycle. Instead of investing in separate molds for each part, a family mold produces multiple parts in a single cycle.

However, this approach requires a meticulous design to ensure even filling and cooling for each part in the mold. But if it’s done right, the returns are well worth the extra effort.

Invest in Multi-cavity Molds for High Volumes

Multi-cavity molds can offer considerable cost savings for projects demanding high production runs.

Unlike single-cavity molds which only produce one part at a time, multi-cavity molds can create multiple identical parts simultaneously. Though the initial investment is steeper than single-cavity molds, the per-part production cost is drastically reduced, making it a sound long-term investment for large-scale production.

Consider Draft Angles

Including a slight taper or draft angle on the surfaces of the molded part can significantly ease the ejection process.

This small design consideration can reduce the wear and tear on molds, decrease the cycle time, and minimize the risk of part defects or damage during ejection.

Choose the Right Material

Materials often constitute a significant portion of the production cost in injection molding.

While some projects require specific, high-grade materials, others might achieve the same functional goals with more economical alternatives. Engaging with product partners and staying updated on the latest in material science can present cost-effective options without compromising quality.