Medical Molding: Precision Injection Molding of Medical Device

injection molding solutions, product development

Medical molding is one method of creating dependable and long-lasting medical-grade components that adhere to FDA regulations. The process offers numerous benefits, making it the preferred method for producing cutting-edge medical equipment today.

When you consider the finest medical equipment and laboratory facilities, you can unquestionably attribute their superior finish to the plastic medical molding process. The procedure’s cost-effectiveness combined with its remarkable accuracy and consistency are its strong points. Additionally, it is useful in situations where a high production volume necessitates a masterpiece level of construction.

It should come as no surprise that the FDA uses this procedure for medical prototype development approval given the caliber of its output. Here, we go over the details of this medical molding procedure and its application in the healthcare sector.

Medical Injection Molding

Advantages of Plastic Injection Molding for Medical Parts

Medical molding stands out among similar production methods in the industry, offering numerous advantages due to its seamless operation, including but not limited to:

Wide Range of Material Choices

While medical molding narrows the scope of materials, it still provides a diverse selection suitable for manufacturing medical-grade components.


The structure of the medical molding process reduces unnecessary costs, particularly in high-volume manufacturing, resulting in a lower cost per part as production quantities increase.


Plastics used in medical molding are known for their rugged durability, offering robust strength and resistance to harsh environments, heat, blunt force, and vibration. Products from this process withstand sterilization in autoclaves without compromising integrity.

Exceptional Accuracy

Precision is crucial in medical device manufacturing, and plastic injection molding ensures exceptional accuracy with tight tolerance margins. Skilled injection molding facilities are essential to achieve the required level of precision.

Resistance to Contaminants

Materials used in the medical molding process resist contamination and require minimal sterilization to meet FDA standards and other regulatory requirements, making them well-suited for medical molding applications.

Applications of Medical Molding

Plastic injection molding plays a pivotal role in the varied applications within the medical device industry. This manufacturing process is favored by medical molding suppliers for its ability to meet stringent standards of quality and safety. Plastic injection molding in the medical device industry is widely utilized in the production of:


  • Dental X-ray Equipment
  • Orthopedic Devices
  • Components and Equipment for Drug Delivery
  • Laboratory Supplies, including Test Tubes, Beakers, and Containers
  • Preparation Equipment for Surgery and Surgical Implements
  • Housings, Casings, and Enclosures for Medical and Laboratory Equipment

Medical-Grade Plastic Materials Used in Medical Injection Molding

The medical molding process leverages a diverse array of materials to manufacture medical and pharmaceutical components efficiently. Several plastic injection molding materials contribute to the efficacy of this process, including:

Polypropylene (PP)

Renowned for its ruggedness and durability, Polypropylene features strong chemical bonds, making it a preferred material for manufacturing medical devices such as beakers and test tubes.

Polyethylene (PE)

Serving as a primary component in the thermoplastic industry, Polyethylene comes in various variations with different levels of rigidity, including LDPE, HDPE, and UHMW. UHMW is commonly used in prosthetics for joints like the hip and leg.

Polystyrene (PS)

Exhibiting high impact resistance and machinability, Polystyrene is a robust plastic with minimal elasticity, often used on easily customizable surfaces, ensuring good dimensional stability and aesthetic appeal.

Polyetheretherketone (PEEK)

Known for its high performance and outstanding mechanical properties, PEEK boasts high-grade resistance to wear, radiation, tracking, and thermal degradation.

Polymethyl Methacrylate (PMMA)

Also known as acrylic glass, PMMA is rigid, tough, durable, UV-light resistant, and weatherproof. With excellent light transmission and chemical resistance, it is used in manufacturing endoscopic medical molding parts.

Polyvinyl Chloride (PVC)

A versatile medical polymer, PVC exists in flexible and rigid forms, both suitable for various medical molding applications, including devices for hemodialysis, tubing, cardiac catheters, and artificial limb materials.

Polyamide (Nylon)

Known for its tensile strength, high abrasion resistance, chemical resistance, and flexibility, polyamide is applicable in CNC machining, injection molding, and 3D printing, producing medical molding parts like stent delivery systems and prescription bottles.

Acrylonitrile Butadiene Styrene (ABS)

ABS, made by polymerizing styrene and acrylonitrile with polybutadiene, exhibits tensile strength, high abrasion resistance, and anti-corrosive properties. It is utilized in medical molding products like non-absorbable sutures and tracheal tubes.


Highly sought after for its flexibility in medical device components, silicone offers exceptional durability and biocompatibility. Its affordability makes it a cost-effective choice, especially in high-volume productions.

Considerations in the Plastic Materials Selection for Medical Molding

The plastic injection molding process for medical devices is a critical undertaking with a substantial risk of failure. Therefore, careful consideration of various factors is essential during the design, planning, and operational stages:

FDA Requirements

Adhering to FDA requirements is paramount in medical component manufacturing. The stringent regulations for sterility and cleanliness demand strict compliance throughout all production stages. Ensuring that all inputs meet or exceed these standards is crucial for achieving medical-grade approval.

Sterilization Compatibility

Plastic materials used in medical molding must be contaminant-resistant and capable of withstanding sterilization processes without sustaining damage. This characteristic is vital for components that come into contact with the human body.

Operational Environment

Plastic molding materials need to exhibit resilience and durability when subjected to adverse conditions such as heat, corrosive substances, liquids, vibrations, and other movements associated with the human body. Many plastics commonly used in medical molding excel in meeting these requirements.

Durability and Strength

To minimize biohazards in the medical field, it is imperative to avoid breakable plastics in device manufacturing. Therefore, each selected material should possess a satisfactory durability index and demonstrate a high level of tensile strength.

General Use

Consider the intended area of use for the material before making a selection. For example, materials for single-use items like syringes, needles, tubing, and connectors should be transparent, flexible, and easy to sterilize. Similarly, surgical injection parts should be lightweight and ergonomic.

Typical Injection Molding Techniques for Medical Device Manufacturing

Different plastic molding techniques are used by manufacturers offering injection molding services to create parts of medical grade. However, we’ll focus on the four prevalent kinds here, which are as follows: Thin wall molding, Gas-Assisted Injection Molding, Metal Injection Molding, Liquid Silicone Injection Molding.

Thin Wall Molding in Plastic Injection for Medical Devices

In the realm of plastic injection molding for the medical device industry, thin-wall molding stands out as a prevalent process. Primarily employed for creating tools or components that balance functionality with patient comfort, this method involves producing injection parts with walls much thinner than the overall pieces, typically measuring less than 1mm in thickness.

Devices and tools manufactured through thin-wall molding demand high material requirements to ensure integrity and durability despite their thin walls. Common base materials for such applications include plastics, particularly LCP (Liquid Crystal Polymer), Polypropylene, or nylon. The material selection is closely tied to the specific object being crafted, and prototypes undergo extensive testing to ensure usability.

Examples of devices produced through thin-wall injection molding encompass wearable devices, surgical tools, and catheter ablation tools.

Gas-Assisted Injection Molding

Gas-assisted injection molding represents a more intricate molding technique designed to address challenges encountered in regular molding, where thicker parts tend to dry or solidify slower than thinner walls. This discrepancy often results in misshapen, aesthetically flawed, and structurally weaker resin due to sink marks.

In gas-assisted injection molding, a solution to this issue is implemented by introducing gas, typically Nitrogen, through channels within the mold. This gas flows through the middle of thicker sections, generating the necessary pressure to tightly press the resin against the mold. The outcome is a smooth, structurally sound part with no sink marks.

While gas-assisted injection molding may not be suitable for tools with sharp corners in their design, as gas pressure decreases with non-linear flow, it excels in producing complex parts.

Metal Injection Molding

The utilization of metal in medical device manufacturing holds undeniable significance, particularly when the need arises for equipment characterized by high density, small size, and maneuverability. This acknowledgment, however, does not diminish the various applications and advantages offered by conventional 3D printing, medical plastic molding, or gas-assisted molding.

In essence, atomization technology is employed to create a powder mix comprising desired metals. This powder is then formed into a pellet, known as feedstock, incorporating a binding agent that facilitates molding.

Following the injection process, the removal of the binding agent is carried out through diverse methods, including solvents, catalytic processes, thermal furnaces, or a combination of these approaches. This results in injection parts with 100% density.

Liquid Silicone Injection Molding

Certain medical devices, such as tubes and respiratory masks, pose challenges in maintaining hygiene. Liquid silicone injection molding emerges as the preferred method for producing such equipment.

The stringent requirements of this process necessitate a hygienic production environment to prevent the settlement of ambient air, dust, or moisture on the mold or mixture during the setting process. The rubber-like substance produced through this method exhibits high chemical resistance.

Silicone’s inert nature avoids reactions with biological tissue, enhancing its suitability for safe implantation. However, this medical molding process involves multiple steps, contingent on the desired properties of the resultant silicone product.

Medical Molding Services

The industry has been revolutionized by the ground-breaking invention of the medical molding process. Producing medical injection parts not only meets established industry standards, but also facilitates a seamless user experience.
For further details, go to our Injection Molding Services if you’re searching for a medical molding parts manufacturer. We provide you with our wealth of injection molding experience, including injection parts for medical molding applications. In addition, we offer detailed reports of inspection and material testing, as well as custom injection molding services at competitive prices.
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1. What is Medical Injection Molding?
Medical injection molding is a cost-effective and efficient method for producing medical and pharmaceutical components, including devices, laboratory tools, equipment, and testing instruments. Products manufactured through medical injection molding exhibit high precision, quality, and accuracy.

2. What are Medical-Grade Plastics, and are they Safe?
Medical-grade plastics are plastics specifically designed for creating medical products, including Vitro diagnostics and primary packaging items. These materials are safe for use in medical applications and help preserve and contain medicines, preventing contamination in pharmaceuticals.

It is safe to use medical-grade plastics to create medical components. The qualities that contribute to safety are hardness, resistance to chemicals and heat, permeability, and—above all—biocompatibility. These plastic polymers are non-permeable, which prevents the growth of organisms that cause disease. Because of their resistance to heat and chemicals, they can also be sterilized. As a result, medical grade polymers are appropriate for manufacturing products used in the transport of bio-hazardous materials that can spread dangerous infections.

3. How is Plastic Used in the Medical Field?
Plastics play a crucial role in various medical applications, particularly in plastic injection molding for medical parts and tools. Items such as syringes, surgical gloves, IV tubes, catheters, and more are manufactured using plastics. These products are designed for single-use, eliminating the need for sterilization and reducing the risk of spreading highly contagious or virulent diseases.

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