Cost Considerations for Medical Device Molding

Over the course of nearly two decades, I’ve been involved in the development of various components for a wide array of medical devices. From insulin pumps to surgical tools for cataract procedures, enteral feeding systems, and diagnostic equipment, the range of projects has been extensive. As medical molders, our role often involves collaborating with clients to enhance design for manufacturing efficiency, part quality, and cost-effectiveness. Today, our focus has shifted towards supporting high-volume automated manufacturing processes where cost optimization is paramount, particularly when producing tens of millions of parts annually from a single injection mold. It is crucial to identify mutually beneficial strategies to reduce the overall cost of medical devices in a sustainable manner, moving beyond traditional cost-cutting models.

UPFRONT COLLABORATION

Upfront collaboration with your supplier(s) is certainly important, especially when it comes to gate optimization, runner type, mold cavitation, as these components will lead to cost improvement. Equally important to the OEM / Supplier partnership, is collaboration within the various departments of your company. Too often, I’ve seen when R&D becomes siloed, and the scope of the project begins to drift after numerous iterations, design changes, material trials, etc.

Although cost impacts all divisions within an organization, the reality is, I’ve seen this first-hand R&D may have different wants & needs than someone in a procurement role who is historically tasked with cost savings. For this reason, I believe it’s important to have a representative from your procurement or operations team working along with R&D to ensure the cost of the device remains within the original scope. If changes to assembly methods, raw materials, or labor led to increased costs, it’s critical to maintain traceability throughout the development process. This ensures a clear understanding of the factors driving these unforeseen expenses.

COST DRIVERS FOR MEDICAL INJECTION MOLDERS

When quoting any injection molded component, there are numerous inputs we account for. These include raw material, labor, cycle time, packaging, mold cavitation, scrap, and profit. Of course, some of these inputs have a greater impact than others, so I want to focus on the main cost drivers that have the largest influence on overall part cost. Most often, mold cavitation will have the largest immediate impact on cost, but mold cavitation is largely driven off the volume of the device. Therefore, I’m not going to spend too much time on mold cavitation, since again, volume (and sometimes part complexity) will drive that need.

Raw Material

There are literally endless types of medical-grade resins on the market today, many of which can even be customized for a specific application. While it’s great that so many options exist today, there are certainly some hidden “red flags” to be on the lookout for.

Custom Made Materials: Once you have started down the path of a custom grade material, you have essentially single-sourced yourself to that material supplier. This makes negotiating quite difficult since it’s well known the hurdles to change a material once the device is FDA approved. Therefore, when possible, I highly recommend trying to pursue a more widely used raw material that is supplied by numerous distributors and certainly is not custom-made for your application.
Minimum Order Quantities (MOQ): When evaluating different materials, ask your material supplier for details pertaining to MOQ’s and lead times. I’ve seen cases where OEM’s picked material that was quoted at a reasonable $/lb.; however, it required a minimum purchase of a truck load, which is equivalent to 40,000lbs of resin! In that specific case, it would have resulted in a several-year supply of material to achieve their targeted material price. So, make sure you understand all the pricing tiers and how much material your device will consume at the intended annual volume.

Cycle Time

Cycle time is another leading contributor to overall part cost which is usually impacted most by gate location (and type), along with wall thickness.

Gate Location & Type: Spending time upfront to scrutinize your gate location through prototyping and/or mold simulation can possibly save you tens-of-thousands of dollars later in production. Improper gating can lead to prolonged cycles times, especially if you are gating thin-to-thick, and need to artificially keep the gate from freezing to fill out the thicker wall sections. This can also lead to other quality related defects. For these reasons, it’s important to select the correct gate location during that DFM phase of the project. Also, gate location will have a direct impact on the type of runner system you can design and build. Ideally, finding a gate location that will provide you with a full hot runner solution is going to be most cost effective. With that system, you will attain the obvious raw material savings, and typically a faster cycle time. However, comparing hot versus cold runner is largely driven off the gate location and size of the part.
Uniform Wall Thickness: I realize this one is easier said than done since there are applications when it’s simply not possible to maintain a consistent wall throughout the entire part. Remember that plastic is an insulator and will want to retain that heat. So, your cycle time (specifically cool time) will be directly impacted by the thickest region of the part. Void coring and structural ribs can often be a great alternative, and there is much more information available on proper part design using these techniques.

Labor

I’ve seen labor increase the cost of a medical device for numerous reasons. These can range from secondary operations (i.e. pad printing), increased inspection, special packaging, etc. The expanded use of automation has certainly helped address what I have noted above, but even with automation, there are added costs to consider. Bottom line, to be cost-competitive in the United States, we need to look for any / all opportunities where we have a single person assigned to a specific operation, often referred to a “full operator”.

Secondary operations such as pad printing, laser engraving, etc. are sometimes unavoidable if that device needs to be easily legible, or used to mark a certain fluid level, so those are certainly exceptions. However, I have seen cases where our customers wanted to have their company logo pad printed onto their single-use device. While certainly feasible, that additional option can sometimes lead to hundreds of thousands of dollars in upfront automation equipment, plus the added expense to the part cost to accommodate that request. Whereby, engraving that same logo in tool steel would virtually eliminate those costs.
Special packaging is another cost driver but is certainly case-by-case. Normally, our customers’ parts are shipped bulk packaged, which is the most cost-effective means. However, if we are dealing with situations that require tray packaging, layer packaging, etc. those requests will certainly have a direct impact on the cost, especially if we cannot automate the handling of the component.

In summary, these are just a few of the examples we’ve encountered over the years that have an impact on the molded part cost. I encourage anyone who is involved in the development and manufacturing of your medical device to engage your supplier(s) early and often. Have a transparent conversation about your pricing goals and what it would take to achieve them. Revalidating existing devices with new materials, gate locations, or designs poses a significant challenge. Despite the complexity of this task, exploring these opportunities is essential as they can uncover valuable low-hanging fruit!

ABOUT THE AUTHOR

Dan Snyder is the Technical Sales Manager and joined Plastikos in 2008. He holds B.S in Plastics Engineering Technology from Penn State University. Dan’s primary role at Plastikos is working directly with medical device OEM’s on new & existing devices, providing technical support throughout all phases of the lifecycle of the device. Outside of work, Dan is an avid outdoorsman’s enjoying mountain biking, skiing, hunting, fishing, and coaching his two sons in sports.