World-class manufacturing

Injection Molding for Medical Devices in a Nutshell

Image So many medical devices use plastics in their manufacturing. The material is easy to sterilize, and plastics have a variety of uses based on their physical properties.
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For medical and pharmaceutical items, every step from design to final inspection holds critical importance for patient health and safety. It’s essential to maintain high-quality standards throughout the production process, emphasizing the role of injection molding for medical devices.

These strict standards make it vital to work with a seasoned manufacturer of medical/pharmaceutical components that values quality and provides full part traceability from beginning to end.

Plastic injection molding can produce high-precision, accurate, and high-quality medical and pharmaceutical products quickly and affordably. Manufacturers use injection molding to make parts from lab tools and testing equipment to medical monitoring tools and devices.

Next is an overview of the plastic injection molding procedure, its crucial function in the pharmaceutical and medical sectors, and more.

Plastic Injection Molding: What Significance Does It Have in the Medical Industry?

Plastics are widely used in current manufacturing operations due to material manufacturing processes and technological improvements. These same improvements allow for their utilization in the medical and pharmaceutical sectors in conjunction with the injection molding technique to create prototypes and full-production units of medical devices and equipment components. As a result, injection molded plastics have a growing impact on the reduced incidence of infectious diseases, improved pain management, and decreased healthcare expenses as newer plastic materials and component designs are created.

Plastic injection molding is popular in medical device manufacturing because modern processes allow for affordable single-use items, tight tolerances, and sterile surfaces.

Benefits of Plastic Injection Molding for Medical Use

Plastic injection molding has several definite advantages over other plastic manufacturing processes, notably when partnered with an experienced and qualified injection molding partner. These advantages include the following:


Industry standards and regulations can be met using engineering-grade plastics in plastic injection molding processes to produce components that improve patient safety and adhere to FDA rules. These medical plastic components are also easier to clean, need less finishing work than their metal counterparts, and resist contamination.

In 2020, Bill Gates famously raised concerns over COVID-19 vaccine effort, mainly the challenges behind manufacturing a billion glass vials and a billion plastic caps, all up to the highest standards.


Traceability is crucial in the healthcare and pharmaceutical sectors. This benefit assures customers that manufacturers actively and meticulously oversee every stage of the manufacturing process.


Plastic injection-molded parts with tolerances close to those of metal parts display remarkable mechanical qualities, such as tensile strength and high-temperature resistance.


Even though injection molding operations produce some material waste, there are mechanisms to recycle extra plastic to improve sustainability overall and lessen environmental impact.


Frequently, transparent, uncolored materials are used, so manufacturers can alter the color of each element to suit the requirements of the customer precisely.


In the manufacture of medical devices, a few millimeters or microns can distinguish between a working and a broken component. Medical plastic injection molding businesses must possess the necessary expertise To produce high-precision, high-accuracy components in both small and big numbers,

Injection molding is the best at providing thousands or even millions of the same piece at a low price with some of the highest tolerances available. In medicine, milligrams and milliliters matter.


For big production numbers, injection molding is a manufacturing technique that is both efficient and affordable. Many manufacturers lower labor and electricity costs using energy-efficient machinery and automation technology. Manufacturers can then pass savings on to their clients.

Applications of Injection Molding in the Medical and Pharmaceutical Sectors

As previously said, injection molding is one of the most successful and economical methods for producing parts that adhere to the exacting requirements and standards of the medical and pharmaceutical industries. The lateral flow in-vitro diagnostic test cartridge, which our team made in large quantities, is one example of how the process is commonly employed to produce the tiny, exact pieces required in diagnostic testing kits.

Other types of plastic injection-molded components for the pharmaceutical and medical sectors include:

  • Beakers, test tubes, and other containers used in laboratories
  • Equipment housings and casings for use in the medical and laboratory
  • Equipment and materials for surgery and surgical preparation
  • Components of dental X-ray equipment
Single use storage and measurement tools like blood vials benefit immensely from using plastic over glass, becoming more durable, more affordable, and remaining as transparent and exact in measurement.

Options for Medical-Grade Plastic

Since Manufacturers may use a wide variety of plastic materials in the injection molding process, it is ideally suited for producing medical and pharmaceutical parts from whatever medical-grade plastic is required for the project. Many plastics are acceptable for medical injection molding processes, and each has unique features and performance traits. For medical injection molding, common plastic material choices include:

  • Polyethylene: This thermoplastic is frequently utilized in both industrial and commercial items. It comes in several varieties with different levels of rigidity and durability, including LDPE, HDPE, and UHMW. UHMW is frequently used in knee, hip, and other joint prostheses.
  • Polypropylene: One of the most widely used plastics is polypropylene. It is distinguished by its toughness, elasticity, chemical resilience, and electricity resistance.
  • Polystyrene: This is a rigid plastic that has very little to no elasticity. It has decent dimensional stability, good impact resistance, and excellent machinability. It is frequently employed due to the surface’s adaptability and aesthetic appeal.
  • Polycarbonate: Polycarbonate is a sturdy thermoplastic of the engineering grade that offers dimensional stability and flame retardant qualities. Additionally, it is resistant to damage brought on by impact, extreme heat, and UV radiation.
  • Polyetheretherketone: Also known as PEEK, this is a high-performance thermoplastic with remarkable mechanical attributes, such as resistance to thermal deterioration, wear, tracking, and radiation.

The first stage in selecting a material for a project is paring down the list to the material family that meets the majority of requirements, given the wide range of available material possibilities. These possibilities include tensile strength, temperature, and load rate. Choosing the grade that best fits the job is considerably simpler from there. You can find more information on materials in online databases.

Choice Factors for Medical-Grade Plastics

For medical injection molding procedures, various plastic kinds are accessible, as was already indicated. Each plastic has unique characteristics that affect how it functions in particular applications. When deciding which of the material possibilities to choose, the following are some important considerations:

  • Strength: The material you choose should have the power you need to sustain your application.
  • Industry requirements: The final component should adhere to all FDA and medical industry standards.
  • Operating circumstances: The substance must satisfy all conditions of the application environment. For instance, the material should provide suitable chemical and temperature resistance if the finished part is exposed to chemicals or high heat, such as in sterilizing procedures.
  • Use in general: When selecting a piece of content, consider who will use it and how. For instance, surgical devices ought to be portable, practical, and comfortable. Single-use medication delivery products, such as tubing, bags, needles, and connectors, should also be adaptable, robust, transparent, sterile, and, most significantly, reasonably priced.

As manufacturing techniques progress, medical device technology also gets smaller. Injection molding has made it possible for part sizes to keep up with this demand for smaller devices.

Methods of Injection Molding Technologies

A recent analysis from market research firm 360 Research Reports projects that the global market for plastic injection molding for medical devices will grow from $31.6 billion in 2020 to over $42 billion by 2026.

As you’ve read, manufacturers of these medical device components employ various ways, and some materials, like metals and composites, are better suited to some technologies than others.

We will continue examining various injection molding technologies that produce medical devices, ranging from thin wall molding with liquid crystal polymers (LCP) to the more well-known 3D printing method.

Inhalers like these became prevalent in the second half of the 20th century. Thanks to plastic housings, asthma inhalers can reach everyone who needs them, as they are affordable and plentiful.


In specific medical equipment, thin walls can enhance patient comfort and be functionally advantageous. The phrase merely refers to making a device’s walls thin in relation to the entire piece, but in reality, this usually relates to walls less than 1mm thick.

Although silicone and metal can also be molded using this technology, plastics like LCP, polypropylene, and nylon are typically used as the foundation material to ensure that walls retain their structural integrity as they are made thinner.

Materials are chosen based on the product being produced and have been tested under various physical pressures and temperatures to make sure they can handle the task.

Thin walls can be employed in invasive equipment like catheter ablation tools and endoscopes, as well as wearable gadgets and microsurgical instruments.

If you’re interested in learning more about the minimum wall thickness for your injection molded parts, follow Jaycon’s guide HERE!


Sink marks may appear when parts are produced using conventional injection molding, giving the finished product an ugly appearance and possibly making it structurally weaker than necessary.

The reason for this is that without enough pressure to pack these areas securely against the walls, the uneven distribution might give the appearance that the mold is sunken. In addition, thicker areas of a mold will cool more slowly than thin ones when the resin is injected.

This problem is resolved via gas-assisted injection molding, which involves pumping gas, often nitrogen, into channels created in the mold. The gas produces the pressure necessary to drive the resin tightly against the mold walls, resulting in a smooth part that is structurally solid and free of sink marks. It also carves a hollow path through the center of these thicker parts.

This technique is utilized to produce intricate pieces without any aesthetic flaws. However, it is not advised for parts with sharp corners in their design because the pressure generated by the gas decreases if it doesn’t flow in a relatively straight path.


Although 3D printing, the most well-known method on this list, is not strictly an injection molding technology, it is frequently used to produce prototypes to test designs before they are put into production using injection molding.

However, the currently available technology is not sufficiently advanced to print with the tight part tolerances required in an injection mold. It is highly anticipated this will change in the future. Engineers can also use the 3D printing approach to build actual injection molds, utilizing plastic or metal.

Image of This medical device measures vital signs
Today, most mass produced plastic items are made with injection molding. Additive manufacturing and 3D software in the product development process has made more intricate designs possible.

Molds are frequently produced from plastic using 3D printing since metal isn’t always required to make some medical devices.


Although there are many applications for traditional plastic injection molding and even gas injection molding in the production of medical devices, it is not always the solution. Using metal rather than plastic is often necessary due to its small size, flexibility, and robust mechanical qualities.

Using atomization technology for metal injection molding, engineers can produce A powder from the desired combination of metals. This powder is then made into a form resembling a feedstock pellet. This feedstock also contains a plastic binding agent to make the material easier to mold during the injection process.

After the mixture is injected, the binder is eliminated using a solvent, thermal furnace, a catalytic process, or a combination of techniques, leaving just the metal and producing a product with a density very close to 100%.


Hospitals are generally concerned about surface-borne infections, but some medical devices, such as tubes and breathing masks, require more sanitary maintenance than others.

Due to the chemical resistance of the rubber-like material created using this technique and the use of clean production space to prevent ambient air from coming into contact with the mold and introducing dust and moisture as the mixture sets, liquid silicone injection molding is used for devices like these.

Another advantage of silicone is that it is physiologically inert, meaning it won’t react with living tissue. This way, medical professionals can safely insert such products into the body.

The primary raw material for silicone rubber is sand, or silicon dioxide, which is converted into pure silicon and reacts with methyl chloride. Depending on the qualities required for the silicone, manufacturers can use a variety of processing stages.


As you can see, injection molding is vital to the medical field, and continued advancements are crucial as we depend more and more on these processes. Developments will put us on the cutting edge, providing medical and pharmaceutical services to enhance and improve the overall well-being of everyone. The sky’s the limit as far as medical injection molding goes. And the health and safety of patients are in good hands.

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