Plastic Injection Molding Basics You Need to Know In Medical In

  • In medicine, plastic injection molding has many benefits to offer. It is a process that leads to the development of numerous medical and laboratory tools and parts. These have a high level of quality and are very accurately manufactured through injection molding. 


    What’s Medical Injection Molding?


    Medical injection molding is a process in which various kinds of plastic material are used to manufacture medical equipment of different kinds. These tools serve numerous medical purposes and are made out of various forms of medical grade plastic materials.


    The process of carrying out plastic injection molding consists of using an extensive process of medical injection molding.


    The Advantages of Injection Molding in Medical Devices


    Countless benefits may be attained by choosing injection molding techniques for manufacturing medical tools and equipment. A few of these important benefits have been discussed below.


    Low scrap generation


    We all know very well that plastics create a lot of scraps, landfills are dumped with a lot of plastic that is not recycled, and it causes harm to our environment. Choosing to opt for plastic injection molding will minimize that plastic scrap. 

    The plastic parts will be recycled and used to make other plastic products, and hence a positive addition will be featured to the environment as a whole. 




    The plastic injection molding process offers a lot of savings on the part of the cost. This is because there is no loss or wastage of the cost of raw materials. Moreover, using plastic injection molding machines also reduces using labor, and hence labor costs are cut down.


    All these aspects allow the creation of medicinal tools at a very low cost which is always the best thing to go for and save on these products.


    Exceptional accuracy


    Every cut and curve of the medical instrument made out of the injection molding process is always very neat and fine. The accuracy of this process may never be challenged. The quality of the tools is also very good, and no edges are left unfinished.


    Material selection


    There is a need for different medical tools, and each device has its requirement of plastic. So, when it comes to plastic injection molding, you can rest assured that you can get a lot of options to make your selection from versatile material choices.


    Some materials need to be hard, some require flexibility, some should be resistant to scratches, and some must support lubricant use. a variation of the material may easily be sourced out of this process.




    Durability is something so important that everyone looks forward to it in everything they invest into. The same goes for the parts of medical equipment and tools. Plastic injection molding delivers a long-lasting product. 


    The injection molding itself is so beneficial that it allows the plastic to gain more and more strength. This adds to the durability of the plastic when used for manufacturing different medical tools.


    Contaminant resistance


    Plastics used in the manufacture of medical devices are chosen after ensuring that they are based on the property of being contamination resistant. It is one of the crucial concerns for the medical equipment so that no negligence can be applied here. 


    The process of plastic injection molding itself ensures that proper focus is being laid on sterilization and contamination resistance of the materials.


    Application of Plastic Injection Molding in the Medical Device Industry


    The medical device industry needs medical-grade plastics to be used to manufacture required tools and laboratory equipment. Hence, when choosing the plastics to carry out the injection molding process, it is made sure that medical-grade plastic is only used.


    This process of plastic injection molding is applied to numerous aspects of medicine. Ranging from manufacturing medical components, devices, and laboratory requirements, the process covers almost all areas to cater to the plastic needs of the medical field.


    Material Selection for Medical Device Injection Molding


    There could be ample material choices made to carry out the process of medical injection molding to create medical devices. A few of the most common medical-grade plastics commonly used comprise the following.


    Polypropylene (PP):

    Polypropylene is a very strength-oriented plastic choice used to manufacture several medical devices. The main reason for choosing this material is its ability to be highly resistant to heat and radioactivity. 


    The medical devices used in radioactive medical procedures or are subjected to constant sterilization in the autoclave may be made out of this plastic.


    Polyethylene (PE):

    Polythene is also one of the considered plastic injection molding materials used to manufacture medical devices that are required to be light in weight and smooth to touch and wear.


    It won't be able to handle the process of sterilization through autoclave, but it is a very good and suitable choice to manufacture wearable medical devices.


    Polystyrene (PS): 

    Petri dishes play a vital role in medicinal procedures, and these are mostly made out of polystyrene. Polystyrene is a kind of plastic that may not be suitable for sterilization through autoclaving but is used in numerous procedures which consist of surgical and lab products. 


    Catheter trays, trays used in lab research work, and tissue culture procedures are usually made out of this form of plastic, and hence it is subjected to plastic injection molding.


    Polyetheretherketone (PEEK):

    PEEK is a widely used form of plastic in several medical applications. Hip and spine implants consist of using PEEK due to their ability to be bone-friendly. It helps in repairing broken bones.



    Silicon is a plastic injection molding material used in medical instances where a high level of flexibility is required. It may be used in drips, injections, and several other forms of medical devices and can be very cost-effective if produced in high volumes.


    Medical Device Plastic Injection Molding Considerations


    The process of plastic injection molding may require a lot of critical analysis beforehand, and there could be instances where the process may fail, and proper planning is required. These considerations are very important to be taken into account beforehand.


    FDA Requirements

    According to the FDA regulations, one of the most important things is to ensure that the level of cleanliness and sterilization is properly maintained. It is very important to ensure that the material used during the process is suitable for medical equipment and that the machine provides clean and sterilized parts.


    Withstand Sterilization Processes

    The plastics used in injection molding must have the capability to withstand the process of sterilization. It is very important to sterilize the plastics before being subjected to the injection process to meet medical standards.


    Suitability to Extreme Environment

    Medical grade plastic must have sufficient strength and resistance that it is capable of handling the extreme environment. Sometimes, it is radiation, sometimes heat, and when inserted into the human body, associated pressures are also laid down. So, the strength of plastic matters a lot.


    Durability and Strength

    Plastics that are brittle and easy to break won't have a place in medicine and hence must be avoided. They always create a risky situation. Therefore it is very important to pass such plastics through injection molding processes capable of being strong, flexible, and durable.


    Common Forms of Injection Molding Techniques for Medical Devices Manufacture


    There are commonly used types of injection molding techniques used to manufacture medical devices may comprise the following:


    • Thin wall molding

    This process ensures a high level of comfort to the patient and is commonly used for manufacturing wearable medical devices like catheters and endoscopes. In this technique, the wall of the medical device is kept very thin, about less than 1mm.


    • Injection molding with gas

    This kind of injection molding is carried out to ensure that no uneven surfaces and rough patches are left while modeling the medical devices. When the resin is passed through the molding process, the thicker areas take time to set compared to thinner ones.


    In the gas application technique, the injection molding is subjected to the nitrogen gas that moves about all the cavities of the molding process, ensuring a smooth path is created for the medical device manufacturer.


    • 3D printing

    3D printing itself is not an injection molding process, but somehow it gives a base for creating medical devices. This process helps create a design before the actual medical device is passed through the molding process for creation. 

    This process gives a plastic base molding base for allowing a medical device to be created.


    • Liquid silicone molding

    Silicon is one of the most commonly considered plastic materials in medicine; its flexible nature and ability to be sterilized and hygienically maintained make silicon popular. 


    Liquid silicon is used for injection molding, and medical devices like respiratory masks, cannula tubes, and many other medical devices are manufactured.




    The plastic injection molding process in the medical field requires a lot of consideration. It is used to deal with medical procedures of different nature and hence needs to meet several regulatory requirements and ethical stances. 

    Hence, everything needs to be analyzed properly, ranging from the material process.