The Importance of Plastic Injection Molding for Medical Equipment

Published on November 1, 2023

Because of its many capabilities and advantages over other means of mass production, a lot of medical equipment is made via plastic injection molding. For medical device markets, however, it’s important that these tools for the healthcare industry are made so that they work effectively under difficult conditions, which limits the use of certain polymers. Reactive materials pose a risk when used in medical situations, as they can corrupt medical tests or cause lifesaving drugs not to work effectively. Because of this, designers of products that wish to use plastic injection molding for the medical device market and in other healthcare situations need to carefully consider what materials to use, along with any mechanical design features. In so doing, medical product designers can determine how to best engineer features that optimize their function.  

As a technology, plastic injection molding is well over a century old. With refinements since its invention in the 19th century, there have been significant developments that have improved upon these processes for fabricating products made from plastic. Injection molding for the medical device market has proved to be a boon for the healthcare industry as a result since it allows manufacturers to make complicated yet reliable products with complex geometries rapidly. Additionally, advanced software for creating digital models has become an important tool for injection molding companies, as it has with other manufacturing methods. With machines that perform plastic injection molding for the medical device market and other healthcare products, designers can utilize computer-aided design (CAD) and computer-aided manufacturing (CAM) software to ensure their products are of the highest quality. All this has brought down costs for medical equipment, offering benefits to both producers and consumers.

Importance of Plastic Injection Molding for Medical Devices & Implements 

Plastics offer advantages over other materials used for equipment in the healthcare industry, with many of these devices and tools made using plastic injection molding. For medical devices, tools, and other equipment, polymers offer better strength and stability while allowing manufacturers to make more complex structures at lower costs. The US Food & Drug Administration (FDA) scrutinizes these processes for biocompatibility, material toxicity, mechanical performance, and other aspects of products made using plastic injection molding. For the medical device market, this ensures that products are safe and effective, and once approved, this allows for their mass production without significant deviation.

Advantages of using plastic injection molding for medical devices and implements include: 

  • Accuracy: Considerably tight tolerances can be achieved through injection molding techniques that can pass the standards set by the FDA and other regulatory bodies.
  • Complex geometries: The capabilities of plastic injection molding allow for the complicated and detailed shapes necessary for parts and products used within the medical equipment industry.
  • Consistency: Automation in injection molding ensures components for medical equipment come out of the dies or molds shaped consistently the same.
  • Contaminant-resistant: The materials used in plastic injection molding for the medical device market must resist contaminants and corrosion per regulations and industry standards.
  • Cost-efficiency: The high volumes at which injection molding can produce plastic medical devices and equipment allow them to be made more economically, especially when automation reduces labor costs.
  • Durability: Regardless of the industry, plastics used in injection molding tend to be rugged, resisting wear caused by vibrations, impact, and heat, among other forces.
  • Material choice: Though plastic injection molding for the medical device market doesn’t permit certain materials, the range of options is wider than with other manufacturing methods.
  • Precision: As the FDA and other regulatory agencies require, the injection molding process can produce sufficiently tight medical equipment tolerances.
  • Quick production: Once a mold is produced, high-volume production through automation allows the fabrication of almost identical components or products quickly, often within minutes or seconds.
  • Scalable: With plastic injection molding, switching from low to high production volumes is easy, and vice versa.
  • Sterility: In the same way materials used in plastic injection molding resist contaminants and corrosion, they’re also easier to sterilize in accordance with relevant regulations and industry standards.

These are all reasons to use plastic injection molding for the medical device market and fabrication of other healthcare equipment. This is largely due to its capability to mass produce robust products in a readily repeatable fashion. Though machining molds and dies are expensive, they can last for many years and through millions of cycles, making them very cost-effective for larger and ongoing production runs.  

High Volume Production & Applications 

Making medical products begins with an injection molding tool, along with either a die or mold, as with other products made by making medical equipment from plastic. Injection molding for the medical device market and the production of many other therapeutic healthcare products enables high volumes of complex components, as it does for many other industries. The injection molding process allows manufacturers to make hundreds of identical medical components rapidly and inexpensively. The greater the production volume, the lower the costs, which makes plastic injection molding for medical device markets for single-use products like syringes and lab equipment like test tubes and other containers.  

Applications

Plastic injection molding for the medical device market can be used for various applications. Other medical products are made using injection m as well, due to the qualities that plastics provide.

Products made from plastic injection molding for the medical equipment market include: 

  • Casings, enclosures, and housings for medical devices and other equipment
  • Containers for laboratory work, like beakers and test tubes
  • Dental X-ray apparatus
  • Mechanisms that aid in drug delivery
  • Orthopedic devices
  • Preparatory kits for surgery
  • Surgical tools

Plastic is used for multiple other medical applications due to its lower cost, flexibility, and ability to survive within the human body without breaking down.

Properties of Plastics Used 

Another advantage for medical equipment manufacturers is the properties provided by the various types of plastic. Injection molding for the medical device market uses resins that can be easily customized to not interact with chemicals used in medical settings, medicine bottles, and other containers. Additionally, directives like the European Union’s Restriction of Hazardous Substances (RoHS) offer strict guidelines for medical devices.

These are some of the most commonly used plastics within the medical industry: 

  • Polycarbonate (PC): Able to survive impacts, this strong see-through plastic remains stable in both hot and cold conditions while also resisting flames and degradation from ultraviolet light; PC is often used for blood filter housings, centrifugal force separators, and high-pressure syringes.
  • Polyetheretherketone (PEEK): Resistant to both wear and extreme heat, these plastics resist degradation due to high temperatures, have excellent optical clarity, and offer outstanding biocompatibility; employed in dental and orthopedic implants, PEEK is also used to make housings for medical devices, lenses for cataract surgery and surgical instruments.   
  • Polyethyelene (PE): As it deforms dimensionally when exposed to heated environments, these plastics are limited in where they can be used; PE mostly is utilized to make breather patches, containers and packaging films, though its low weight makes it excellent for surfaces of knee and hip joint replacements as PE offers greater comfort for these implants.
  • Polypropylene (PP): Able to withstand extended periods of exposure to high temperatures, this plastic helps keep samples stable without degrading while also tolerating radiation treatments; PP is often used for test tubes, syringes, synthetic sutures, pouches, pipettes, medical implants and beakers, along with helping in the repair of hernias.
  • Polystyrene (PS): A rigid, naturally colorless plastic with limited elasticity, pigments can be blended with the resin to color it; PS is an inexpensive material that’s often made into lab tools like flasks, petri dishes, and pipettes, along with plastic cutlery used by hospitals.

Numerous other resins can assist in various functions of medical equipment made using plastic injection molding. Certain resins can survive in particularly difficult environments for the medical device market. For example, poly tungsten is made from tungsten powder mixed with various resigns, which can be made into densities that rival lead to offer shielding from radiation as is found in X-rays and certain cancer treatments. Other types of plastics are capable of performing well under a variety of other environmental conditions.

Spaulding Composites: Expertise in Plastic Injection Molding for Medical Device Markets

The capabilities of plastic injection molding for medical device markets are nearly endless. Plastic medical products can take on almost unlimited forms. They can be rigid or flexible while also withstanding extremes in temperatures, exposure to electricity, and corrosion, among many other customizable properties. Perhaps best of all, injection molded products are extremely cost-effective to produce, especially when fabricated at scale.

To understand which of the many resins are best for a certain application, it’s best to contact an industry expert. With the ever-changing nature of medical technology, it’s best to choose a partner like Spaulding Composites, with considerable experience manufacturing for the medical industry. Having worked with industry leaders who make lab equipment, medical devices, and wearable technology, Spaulding can contribute to designs, prototypes, and scaling production in many ways. To learn more about how we can assist with plastic injection molding for the medical device market and how to help with your specific application, contact the experts at Spaulding Composites today.