Manufacturing medical devices is one of the most critical processes in the global economy. World populations are aging rapidly and requiring unprecedented amounts of care, medical aids, and health devices. Meanwhile, current and future pandemics threaten to overwhelm already resource- and cash-strapped healthcare systems. The industry needs reliable and innovative device manufacturing techniques.

Medical device injection molding for manufacturing came to prominence in the last couple of decades because it supports the ever-shifting needs of the industry, including:

• Ever-smaller devices, including implantable and wearable health monitors
• Longer-lasting items to curb material waste
• More eco-friendly products
• Bespoke devices tailored to individual patient conditions
• Product designs ready for mass customization

The market for injection-molded medical devices is expanding rapidly. It was worth $20.3 billion in 2021 and will continue to grow at 5.7% annually until at least 2030.

That growth is easy to understand, considering the innovations in this industry and the many ways to leverage them throughout healthcare. Here are several medical device injection molding manufacturing techniques that improve patient outcomes.

1. Liquid Silicone Injection Molding

Liquid silicone is one of the best and most common ways to use injection molding in medical device manufacturing. This is a strong choice for medical device manufacturers because liquid silicone rubber (LSR) provides improved physical strength, chemical resistance, and thermal protection than previously common materials like latex. LSR is one of the most body-friendly materials the field has discovered.

Here are some of the ways to use liquid silicone injection molding in medical manufacturing:

• High-volume runs: Many manufacturers use LSR for highly precise, large-volume production when they need consistent results.
• Life sciences: LSR’s tight tolerances and biocompatibility make it ideal for creating masks, surgical tools, drug-delivery mechanisms, and valves and diaphragms.
• Consumer health products: LSR is a great choice for consumer-grade products that regularly come into contact with the body. It holds its properties while wet or dry, which is why it finds its way into hearing-aid components, bottle tips, electric toothbrushes, and appliance valves and gaskets.
• Industrial equipment: Manufacturers routinely use LSR injection molding in healthcare-adjacent fields and products like smoke and carbon-monoxide detectors, furnace parts, and water heating and treatment components.

One reason for ever-higher interest in LSR is because of the aging population. LSR is a valuable component of companion and caregiving robots—a rapidly growing portion of the medical device field. Its soft but durable nature makes it ideal for forming grasping tools and other elements of robots that need a soft touch around the elderly or infants. These devices are responsible for delivering medication reminders and a supportive presence, so making them safe and appealing is essential.

2. Metal-Based Injection Molding

Combining injection molding with metal was an innovation first introduced in the 1930s. The practice continued to expand its possibilities throughout the 1970s and became a widely viable manufacturing option in the late 1990s.

Today, metal injection molding (MIM) can create many medical devices and components, including:

• Medical and dental hand tools
• Implants and drug-delivery systems
• Robotic surgery implements
• Orthopedic assistance devices

Devices and parts requiring excellent maneuverability and above-average mechanical strength are a good fit for MIM. The process involves atomizing the desired mix of metals and forming it into pellet-like feedstock using a binding agent. After the part or device is formed by injection, solvents remove the binding agent and leave only the metal behind.

MIM is an advisable choice in many applications where small volumes of products must be produced quickly and inexpensively. The best products for this technique are small and feature complex geometries. Such complexity is more difficult to achieve using other methods, including machining.

3. 3D Printing

3D printing is not itself a medical device injection molding technique but can be used to complement it. There are two ways to do this at present:

• Use a 3D printer to print the molds used for the injection molding process.
• Use a 3D printer to create a proof-of-concept prototype before fabricating the final product using conventional injection molding.

It’s important to note that 3D printing may not yet provide the tolerances required for some highly precise medical device products. Conventionally made injection molds do not have this tolerance limitation, but further improvements to 3D printers will likely eliminate this limitation in the coming years.

4. Gas-Assisted Injection Molding

Injection molding has been a reliable ally in the medical manufacturing space for many years, but it wasn’t always ideal for every project.

Gas-assisted injection molding came about because engineers needed a way to help the thicker-walled areas of the medical device mold cool as fast as the thinner ones during injection. The mechanism requires additional pressure so the workpiece adheres tightly to the walls of the mold. Failure to do this could result in sunken areas in the finished item and compromised structural integrity.

Gas-assisted injection molding came about to solve this shortcoming and unlock a wider range of medical device designs. This makes it easier for engineers to create parts with hollows, tubular sections, and other shapes without sacrificing dimensional strength.

The result is medical implements, implants, and devices that are far stronger than their conventional counterparts while being up to 50% lighter.

What Does the Future Hold for Medical Device Injection Molding? 

The future of injection molding—and related technologies and techniques—is looking bright. In fact, several innovators are zeroing in on further expansions of its potential.

One example is additive molding. This is a fascinating revelation for medical and aerospace manufacturing projects requiring the utmost structural and dimensional strength. It involves implanting a thermoplastic into continuous fibers—a vast improvement compared to conventional 3D printing or casting. It leaves the material fibers intact throughout the workpiece rather than forcing engineers to cut them down to size.

The future will bring even more innovations that blur the line between familiar molding, casting, and printing techniques. As one of the most valuable and essential industries on Earth, medical device manufacturing will certainly be among the first beneficiaries as these innovations come to market.

Artical Source: MPO