Engineering Insights: Metal-to-Plastic Conversion in Healthcare

Summary: Metal-to-plastic conversion in healthcare is accelerating as advances in engineered thermoplastics make plastics a viable alternative to metal in applications ranging from single-use surgical tools to hospital beds. This article explores the key drivers behind the shift, including performance improvements, corrosion resistance, weight reduction, design freedom and supply chain benefits. It also outlines sustainability considerations, regulatory and testing requirements and the material selection process manufacturers should follow to successfully execute a metal-to-plastic conversion.

Healthcare manufacturers are likely familiar with the push to replace glass with plastics in healthcare applications. The trend has led to single-use tools like plastic syringes, which are opened, used and disposed of. Plastic conversion efforts increase the sterility of medical instruments and remove the need to disinfect medical tools and devices before or after use.

“Polymer science and technology have undergone more significant advancement over the last 20 years than in the 50 years before that,” said Brian Rubin, Technical Development Engineer, M. Holland. These technical improvements have enabled the creation of new types of plastic materials that have increased its desirability in applications that traditionally required glass and, more recently, have advanced to the point where plastics can now replace metal in healthcare environments.

Today, M. Holland’s healthcare experts are seeing a new push toward metal-to-plastic conversion in healthcare applications, from single-use surgical tools to capital equipment like hospital beds. Explore the advantages and process of metal-to-plastic conversion in healthcare to determine if your products could benefit from making the switch.

Performance and Durability Advantages

One of the biggest reasons manufacturers are exploring metal-to-plastic conversion in healthcare is the high performance of modern engineered plastic resins. Reinforced plastic materials can be engineered to match metal’s stiffness, making them a valid replacement for applications that require structural integrity and strength. Plastics do not corrode, an improvement over metal in a healthcare environment that often exposes materials to harsh chemical disinfectants.

Another major advantage is weight reduction, according to Chuck Bialas, Strategic Account Manager, Healthcare. “You can reduce product weight by 40-50% by switching from metal to plastic,” Chuck said.

Brian provided additional details. “Aluminum has a specific gravity of 2.7. The most high-performing plastic alternative, like a glass-filled nylon, has a specific gravity of around 1.6.”

Lower specific gravity translates to easier handling and ergonomics for products like hospital beds, medical tools and portable medical devices. It can also contribute to lower shipping weights and smoother motion in a mechanism’s moving parts.

Design Freedom and Part Consolidation

Beyond performance, manufacturers are drawn to the design flexibility plastics provide when converting parts and products from metal. Designing with metal is more difficult and time consuming than plastics.

Plastic designs can also support part consolidation and simplify assemblies.

“You can often replace four or five metal parts with one plastic part due to the superior designability of plastics. Reducing the number of parts makes assemblies easier and more cost-effective,” Brian said.

In addition, reducing part numbers can improve manufacturability and streamline production.

Patient and Clinical Benefits

Metal-to-plastic conversion in healthcare has direct patient and clinical benefits. Lighter weight designs support portability and ease of use for patients, caregivers and medical staff in everyday settings. For example, lighter plastic hospital beds can often be managed by one person instead of a team.

Safety is another major benefit. Plastic provides protection against cross-contamination in single-use applications. Medical tools delivered in sterile packaging do not require additional disinfection before or after use. This allows sterile instruments to be on-hand and available for immediate use.

For reusable medical tools and devices, plastic can be specified to withstand the preferred sterilization method, preventing damage related to harsh disinfectant chemicals used in a healthcare environment.

Manufacturing Economics and Supply Chain Realities

Cost and supply chain factors are also influencing metal-to-plastic conversion in healthcare. It is generally less expensive to produce a plastic product than metal, especially when manufacturers consider part consolidation and high-volume production.

Regional processor availability is another important factor. According to Strategic Account Manager, Healthcare, Jon Moellendick, “A key healthcare manufacturing trend is building a more regional supply chain. Globally, there are more injection molders than there are foundries, which often allows manufacturers the option to mold geographically closer to where products are assembled.” Processing parts closer to the final assembly point can reduce transportation distance, lowering fuel use and carbon emissions related to manufacturing.

The Sustainability Question

Metal-to-plastic conversion in healthcare also has a sustainability benefit. Lighter weight products ship with less fuel used, improving overall carbon footprint.

A report published in the Environmental Science & Technology Journal found that plastics had lower greenhouse gas emissions in 15 out of 16 applications studied and released 10-90% fewer total life-cycle emissions than the next-best alternative.

But what about the plastic waste problem? Single-use plastics do contribute to medical waste, but sustainably minded engineers can take action to balance wellness, waste and sustainability. Use this guide to explore sustainable solutions for the healthcare industry.

Designing a Successful Metal-to-Plastic Conversion

Execution is critical in successful metal-to-plastic healthcare conversions. M. Holland’s healthcare experts agree that the design process should begin by identifying the end product’s intended use.

“Before selecting a material, manufacturers should begin by determining necessary functionality and the environment where a plastic part will be used,” said Brian. “Parts may be required to pass biocompatibility testing depending on where and how they are used in the healthcare environment. This is just one factor you need to determine before finalizing material selection.”

Other considerations include areas where force will be applied to the product, sterilization expectations and potential chemical contact, whether the part will be in a fluid path and what the fluid will be. Review the tips shared in Streamlining Mobile Medical Device Design to further optimize the medical design process.

Once the function and environment has been clearly determined, material selection can take place. Healthcare manufacturers often need resins that offer high stiffness, higher impact and strong resistance to heat, chemicals and sterilization. Products must also stand up to corrosive cleaners.

Polysulfones and high-heat nylons are two material examples that are often good choices in metal-to-plastic conversion. Explore additional material selection considerations for healthcare environments here.

Testing and Regulatory Standards

Switching from metal to plastic will require product validation and testing. If the part will come in contact with fluids, tissues or chemicals, more testing will be required before you can release a plastic product to market.

If a product comes into contact with the human body, engineers should ensure it meets standards like ISO 13485 for biocompatibility. Tools like surgical instruments are required to meet biocompatibility standards but a plastic hinge on a medical bed may not require certification of biocompatibility.

Partnership with your resin distributor is key during a metal-to-plastic redesign. Many, like M. Holland, have technical resources to complete analysis and testing for specific product requirements and can provide material options that are more tailored to your specific purpose. Regulatory resources are also available to ease the path to product approval and market release.

Visit our Healthcare market page to learn more about how we can support your metal-to-plastic conversion in healthcare and subscribe to receive the latest news and insights from M. Holland.

Frequently Asked Questions

1. What are the performance and durability advantages of plastic over metal in healthcare applications?

Modern engineered thermoplastics and reinforced polymers can deliver high strength, stiffness and chemical resistance in demanding healthcare environments. Unlike metal, plastics do not corrode, which can be an advantage in applications exposed to moisture, disinfectants or harsh cleaning agents.

Plastics also offer significant weight reduction compared to metal, improving ergonomics for healthcare staff and portability for patients. In many cases, high-performance plastics can meet functional requirements while also enabling part consolidation and improved design flexibility.

4. How does switching from metal to plastic impact regulatory testing and validation?

If the component will contact fluids, tissues or chemicals, manufacturers may need to conduct more extensive testing before releasing the product. Depending on the application, requirements may include biocompatibility evaluation and compliance with standards such as ISO 13485.

For example, a surgical tool used in the body will require more regulatory scrutiny than a hinge or structural component on a hospital bed.