What is Medical Injection Molding?

Medical Injection molding has become an adaptable technique to fabricate medical components. It refers to an additive manufacturing technique that is used to form stringent quality standard medical devices with relative ease, as compared to other conventional methods. This injection molding technique allows for specific control of the size and shape of the products. And always ensure compliance with the regulations and standards of the FDA.

The process is carried out in a clean, and anti-bacterial environment to maintain hygiene and meet the needs of patient safety. Further to prototype development, injection molding is considerably an effective technique to design complicated design FDA-approved functional prototypes in a shorter time lead.

Injection molding is a notably fastidious, and efficient way to design patterns for medical devices from a broader prospect. It allows medicare designers to use multiple medical-grade thermoplastics like ABS, nylon, polyethylene, Delrin, polyethylene glycol, etc.  Moreover, injection molding is not limited to medical devices but is also employed to fulfill many industrial needs in terms of making ideal prototypes for testing and validating designs.  For instance, from handy pens to industrial tooling, and dies making, injection molding is considered a crucial technique to meet these critical requirements.

Materials Used In Medical Injection Molding

There are various thermosets to thermoplastic resins compatible with medical devices. The ultimate choice depends upon the part complexity and intended medical use application.   

Although thermoplastics are the most common type of materials used for medical Injection Molding, there are other plastics called thermosets that can be used for molding, although the process is different. Thermoset materials can not be used to produce medical Injection Molding because they can not be easily recycled like thermoplastic materials. A good example of these thermosets is your car tires; they cannot be melted down or reshaped. In addition, several other materials are commonly used for shaping disposable medical components. These include;

• Silicon
• Polycarbonate
• Polyethylene
• Polypropylene
• Gas-filled polymer

Benefits of Medical Injection Molding

Medical Injection Molding has so many benefits, they may include:

1. They can be used to create parts that enhance patients’ safety and comply with Food and Drug Administration guidelines
2. It helps to fulfill high-volume orders with high accuracy and precision in minimal turnaround.
3. Compliance with industry standards and regulations. The FDA had set out a series of requirements regarding the safety, cleanliness, etc that equipment must meet before the operation
4. Injection molding helps replicate critical shape medical components with relative ease, all while on an economical budget.
5. It reduces labor and utility costs
6. This process generates water like just any manufacturing technique, but the most interesting part about this technique is that it allows you to regrind and melt excesses and re-use them for other parts fabrication which results in waste management and reduction.

Medical Injection Molding Processes

Here are some of the component processes used for making rigorous standard medical parts or devices;

1. Plastic injection molding: Plastic injection molding helps replicate sophisticated design medical equipment from a wider range of material utilization. This process is recognized for its speedy, economical, and efficient approach to shaping patterns of certain critical medical use parts because it’s carried out in a hygienic, and controlled environment to maintain hygiene and the highest quality standards for end-use medical components.
2. Over molding: As the name implies, this technique combines two layers to form a medical component to enhance its strength, durability, and longevity. In general, the process is known as two-shot molding, because, it requires two crucial steps to make or form a medical product. Medical engineers use it for enclosures and housings of medical device requirements where the long life of equipment is a major concern.  
3. Insert molding: this is almost the same as the over-molding because, in this step, a secondary component is moved over an already molded part- the insert. Although insert molding is a single process as compared to over-molding it is a two-step process. Here the substrate (inserts) is the pre-existing structure. Insert molding technique is not limited to only plastic industry as over-molding is, the insert molded over can be used to make metals and alloys
4. Liquid silicone Injection Molding: Silicon is a medical-grade polymer resin that’s compatible with creating highly durable components. The injection molding process is the heating of silicone to a molten before remolding it into your desired medical production shape. Silicon has gained popularity because of its exceptional strength. It is notably considered equal in strength to aluminum part devices, and heavily adopted for designing functional use medical prototypes, prior to their full-scale production.

Considerations For Medical Device Components

Before one can use medical Injection Molding materials, there are a few things to consider; they may include;

1. Food & Drug Administration Regulations and Guidelines: you must consider FDA regulations for the cleanliness and sterilization of medical components both in parts and the manufacturing process. Any material you select must meet each of these standards for operation by FDA
2. Compliance with Regulatory ISO Standards: Any facility that produces medical components must meet the ISO 13485:2003 standards with additional compliance to class 1, 2, or 3 required depending on the products that are being manufactured. If you are partnering with any facility, confirm that the facility complies with all of its regulations and guidelines.
3. Material properties: The material you choose for the medical component must be biocompatible, and resilient in correspondence to medical devices, and components requirements. These properties may include; steerability, and resistance to chemicals in harsh environments.

Applications of Medical Injection Molding

Medical Injection Molding can be applied to the following areas;

• Trocar handles
• Filters
• Electrodes to patients
• Scalpels
• Components of pacemakers
• The Y connectors
• The EKG Hook-Up Leads
• Female and male Luer locks
• Multi Lumen Catheters
• Needles used for different medical purposes
• Power cords

Medical Injection Molding devices

The FDA federal government of food and drug delivery has specified various classes for medical components. These classes help medicare professionals to check and maintain strict quality standards to meet ISO standards for patient safety. The categories are classified as Class I, Class II, and Class III. These classes dictate parts criteria. For instance; class I components are assumed to be low-risk components. A few examples include; wheelchairs, glasses, hospital beds, and test tubes. Similarly, class II refers to some moderate risk medical use devices which include; contact lenses, syringes, pregnancy tests, etc. In addition to class III, which lies under high-risk devices. Some of the common examples include; defibrillators, implantable devices, catheters, and prosthetics.

Conclusion

Medical injection molding is a technique that can make Food Drugs Administration (FDA) medical devices that are very reliable and 100% reliable. This process produces high-quality products that have good chemical and mechanical properties. It’s cost-efficient and is very easy to fabricate. It can use materials like Silicon, Polycarbonate, Polyethylene, Polypropylene, and Gas-filled polymers for its production process. This injection molding can also be applied in Trocar handles, Filters, Electrodes to patients, Scalpels, Components of pacemakers, The Y connectors, The EKG Hook-Up Leads, etc.

FAQs

Q1. What are medical-grade plastics?

Medical-grade plastics are the polymers of plastics used for the production and manufacturing of medical devices and products. These plastics are usually biologically inert and must pass the test to show their ability to comply with safety and industry standards. They are plastics that have excellent physical and chemical properties. Example, polyethylene, PEEK. etc.

Q2. Can the mold be modified and in what circumstances would that be necessary and possible?

A mode can be modified but the modification is usually little and small. These modifications are always done to help the mold perform better or as part of its cosmetic change. Although modifying a mold is usually costly and must be approved by the customer.

Q3. What is the difference between molding and over-molding?

Over molding is the process of adding another layer of material over a component or a polymer part. An Example is extrusion while insert molding is the combination of plastics or metals into a single unit.