How expensive is injection molding? A complete answer to this question needs to address a number of different engineering factors, consider the cost advantages of offshoring versus reshoring, and pay careful attention to hidden factors that can inflate the cost of your injection molding job.
In this article, we walk through each of these factors to provide a comprehensive guide to injection molding costs.
The most fundamental factors affecting the cost of an injection molding process come from the design itself:
Beyond the direct cost drivers discussed above, it is crucial to consider less obvious factors that may be baked into the cost of an injection molding project. For example, secondary post-molding operations like assembly, finishing, and packaging will add to the project cost.
More broadly, any injection molding operation will ultimately have to pass along its overhead expenses, including energy, labor, and facility maintenance. While these costs may not appear on the invoice, working with an efficient, forward-thinking injection molder is ultimately an important contributor to cost reduction.
Finally, lead times and supply chain costs are crucial factors to consider. A small marginal cost savings can result in far greater lost revenue if it leads to a lost market opportunity, inflated transportation costs, or a less reliable supply chain.
When designing your injection molded part, it is important to consider the principle of “design for manufacturability” (also called “design for manufacturing”), optimizing part design to minimize production costs relative to requirements for form, fit, and function.
Of course, a comparatively expensive part may be appropriate if it delivers strong value in its end-use case. But in many cases, an arbitrary or purely aesthetic design choice may lead directly to a more complex mold and needlessly inflated cost. Striking the right balance of cost and capability for a part requires a value-engineering approach to weigh the costs and end-user value of various design features.
We recommend working with your injection molder to evaluate the manufacturability of your design. Some helpful tips include:
A hands-on injection molding vendor should be willing to work with you to optimize manufacturability for your design while maintaining the required quality and functionality. In many cases, subtle changes to characteristics such as wall thickness can make an outsized difference to overall costs. Taking the time to solidify a cost-optimized design can drive savings both for the project at hand and future production runs of the same part.
Overseas injection molders may be able to offer lower labor rates, overhead, and material costs compared to domestic manufacturers. But it’s crucial to consider additional costs and risks associated with offshoring plastic injection molding projects:
For a deeper analysis of the true costs of onshore versus offshore manufacturing, we recommend the work of the Reshoring Initiative.
In our work with plastic injection molding clients across a variety of industries, we have noticed a sharp increase in the demand for parts made using recycled materials. While we are typically able to accommodate this need using a range of post-industrial (and increasingly post-consumer) materials, the underlying costs have shifted alongside the recent growth in sustainability concerns.
In many ways, the plastic injection molding industry was one of the original industries to offer more sustainable, recycling-based manufacturing options. Scrap plastics have been widely available for decades; in the past, they offered a lower-cost alternative. Today, with increased demand for recycled materials, these materials often command a price premium compared to newly manufactured materials.
When one telecom industry client presented a new fiber optics equipment part design to Molding Dynamics, our team quickly spotted some serious manufacturability issues. In this case, the design employed 86 different nuts and bolts, each one requiring manual assembly and increasing cycle times.
Molding Dynamics worked with the client to understand the part’s requirements. Our analysis suggested that the design would perform as intended with a dramatically reduced number of pop rivets. This change reduced the cycle time for this project from about one day per part to about ten minutes.
For all of the reasons discussed above, understanding the full array of factors driving the ultimate cost (and long-term value) of an injection molding job is rarely straightforward. But there are proven best practices for minimizing waste and aligning costs closely to a given part’s form, fit, and function requirements.
Ultimately, the best way to reliably control costs is to work with a trusted supplier who is committed to cost transparency and willing to work with you to optimize manufacturability.
Interested in working with Molding Dynamics to manufacture your injection-molded part? You can request a quote here.