What is Medical Plastic Injection Mold?

The medical plastic injection mold is the type of mold in which molten metal is drawn into a specific cavity to produce specific medical equipment.

This process is optimized to produce a variety of surgical utensils approved by the FDA (Food and Drug Administration). The materials used in this process are plastics which exhibit a variety of benefits, optimum to make high-degree equipment.

This medical plastic injection molding process can be used to make a variety of medical parts either as subassemblies or as the major parts of more complicated utensils.

Medical Parts manufactured by Injection Molding

There are a number of valuable medical parts that are being manufactured through this process which are undoubtedly high-quality medical parts. Some of them are mentioned below.

  • Needles
  • Pulse oximeters
  • Surgical suture
  • Speculum
  • Tracheal tubes and several other tubes
  • Scalpel and various other blades
  • And much more

All of these parts and several others are efficiently created out of the medical plastic injection molding process. All of the products are capable of high-degree performance and quality.

Materials used for Medical Plastic Injection Mold

The materials used in this process contain a high amount of beneficial substances that are significant for making high-quality medical parts.

These materials include plastics and some other materials that are required to manufacture optimum medical equipment.


A number of thermoplastics are being used for manufacturing medical parts and components. Along with thermoplastics, a variety of thermosets and some elastomers are also being used for this medical plastic injection molding. However, the most important ones are mentioned below.


This primary thermoplastic is being used in the medical plastic injection molding because of its several beneficial characteristics.

The most important feature of this medical grade is that it is highly thermal resilient which makes it optimum to use it in the medical industry.

Moreover, polycarbonate has high tensile and shear strength. Another feature of this thermoplastic is that it is low moisture absorbing medical grade.


This plastic resin is used for its number of beneficial and exotic factors. The most feature of this plastic resin is that it can be pasteurized using an autoclave.

Moreover, this medical grade has intensive chemical resilient properties along with being cracking-free and fatigue-free plastic.

Due to such beneficial features, this medical grade is being used in the medical plastic injection mold process.


This plastic is used because of several physical and chemical properties. The top-most valuable feature is that this plastic is a great resistor of ecological strain and cracking.

Moreover, it exhibits extraordinary geometrical strength and arduousness. Because of these reasons, it is being used in the medical plastic injection mold process.

Other Materials

Other than plastics, there are a variety of other materials which are being used to manufacture medical devices through medical plastic injection mold process. Following is the summary of those materials.


Fiberglass has a lot of exotic features optimum for the manufacture of medical devices. It provides striking insulation to the medical devices.

This feature is necessary for manufacturing medical devices as these devices or parts may get corroded from the harmful rays of the sun.

Therefore, it is essential to insulate these parts. Moreover, fiberglass enables you to have numerous design patterns for the medical parts.

Carbon Fiber

Carbon fiber has a lot of upgraded advantages because of which it is preferred over aluminum or steel. The key benefit of the carbon fiber is that is highly corrosion and chemical resilient.

Furthermore, this material has a high level of strength and arduousness which makes it optimum to use in the medical plastic injection mold process. Another supreme benefit of the carbon fiber is that it is extremely lightweight.


Talc is one of the most important materials to be used in the medical plastic injection mold process. Talc is a mixture of oxygen, silicon, and magnesium.

Talc is a highly absorptive material. This is because it is used in the manufacture of medical components and parts. It is known that talc keeps the skin parched and helps to preclude rashes.

All of the above-mentioned materials are essential to use for the production of medical components and are responsible to give each medical part its own exclusive properties and physical strength.

Medical Plastic Injection Molding Process Cycle

Primary Process

There are four major steps in order to get finely finished medical equipment. Each of the steps holds a significant amount of importance. The following is the summary of the medical plastic injection molding process cycle.


The first step of the medical plastic injection mold is the fastening of the two mold units together. However, the two mold units should be properly cleaned from the previous injection.

Enough force is supplied to keep the two mold units together.

This clamping is operated hydraulically to provide sufficient strength. When the two mold units are perfectly caulked, the second step on injection takes place.


The next step in the production of medical parts is the injection of the molten plastic into the injection unit. However, prior to entering into the injection unit, the plastic is melted under given temperature and pressure.

The plastic is usually in the form of granules which is subjected to the melting. Afterward, this molten plastic is shot into the injection unit to form specific medical components.


Once the molten plastic enters into the molding containers, it is subjected to the process of cooling. It is forbidden to withdraw the material before the shot is properly cooled.

However, when a product is cooled, it shrinks to some extent. Therefore, in order to overcome this loss of the product, several materials are continuously added.

A considerable amount of pressure is supplied to keep the molten plastic packed and secured within the boundaries of the mold cavities.


This is the last stage of medical plastic injection mold process. In this process, the manufactured part is ejected out of the mold cavity.

Sufficient force should be supplied in order to eject the cooled part out of the container. This is because, during the cooling process, the molten plastic sticks to the walls of the container.

Therefore, enough force must be supplied in order to eject the cooled part efficiently without damaging the product. Furthermore, a spray can also be used for the convenient removal of the product.

After the ejection of the cooled part, the product is subjected to trimming off several extra boundaries that may be formed during the cooling process.

The molten plastic gets into the various channels of the mold cavity, thus, forming unwanted corners and edges. Using a trimming machine, these undesirable boundaries are cut off giving a finely finished product.

Secondary Process

Once the cooled part is ejected out of the mold cavity, it is subjected to several other processes in order to get a finely finished medical part or component.


Several parts are combined together in order to get one medical component. This process can be done with the help of a machine or manually.


This process is essential to keep the hold between the two medical parts and components. Several ultrasonic waves are used to form a long-lasting bond between the parts.


This is the end process for manufacturing medical devices. In this, the logos and instructions are printed on the device. Moreover, several intricate patterns are also imprinted on it which enhances the visual appeal.

Advantages of Medical Plastic Injection Mold

Several beneficial features are exhibited by the medical plastic injection mold due to which it is in such a high demand for the manufacture of various medical devices.

High Formation Pace

Injection molding is the type of molding process which makes the products at a higher pace than any other product manufacturing method.

Not only medical devices but also several other devices can also be manufactured from the injection molding.

Medical Plastic injection molding produces a large number of medical devices in lesser time as compared to other methods. Therefore, it is in such a high demand.

Can Manufacture Complicated Shapes

Every surgical module is different from the other. Thus, they vary in shapes and sizes. Some may consist of complicated geometry while other may be simple to manufacture.

No matter which shape the surgical module is, medical plastic injection mold process produces all types of complex and complicated shapes.

Moreover, the time for the manufacture of such complicated modules is the same as that of others. Therefore, the medical plastic injection mold is preferred over other manufacturing methods.

Lesser labor expenses

Medical plastic injection molding is automatically controlled process which is done by machines.

Fewer workers are needed to handle the machinery of the medical plastic injection molding and get the job done.

Hence, in medical plastic injection mold process less labor-intensive force is required which, in turn, tones down the labor expenses. Thus, more capital can be transferred to make high-quality medical modules.

Great geometrical precision

All the materials which are being used have a great impact strength as well as excellent geometrical accuracy.

Therefore, all these qualities are more or less transferred to the manufactured products. 

Injection molding is the process which enables the product to have great geometrical precision, particularly in the medical appliances.

Moreover, medical plastic injection molding also transfers great dimensional stability to the medical modules.

Exceptional Surface polish

Surfacing polish is essential to make the product look out-class and grade A. Polishing is done to make the surface of the material smoother than it already is.

There are many tools are materials used for surface finishing. However, as you reach higher in finishing, the cost for it also exceeds.

However, medical plastic injection mold gives an exceptional and extraordinary finishing to the medical appliances making it smoother and finer to use.

Furthermore, the materials used in the medical plastic injection mold are highly corrosion and cracking resilient which also contribute to the fine finishing and polishing of the medical devices and modules.

Limitations to Medical Plastic Injection Mold

Every beneficial thing has some drawback too which can’t be ignored. Likewise, medical plastic injection mold has some limitation which should be foreseen.

Can Prove to be Costly

The machinery and equipment used for medical plastic injection mold can prove to be much more expensive than one can imagine.

According to a survey, it is estimated that the price of a second-hand medical plastic injection mold machine can be from $5000 to $50,000.

However, the cost of a first-hand, newly constructed medical plastic injection mold machine can be as far as $400,000. Therefore, medical plastic injection mold can prove to be costly and extravagant.

Designing limitations

This is the major disadvantage of the medical plastic injection mold. There are several design limitations and restrictions for the product being manufactured from this process.

Furthermore, the design of the product should be decided before the initiation of this process.

This can not only increase the cost for manufacturing the product but also it can make you a victim of design restriction.

Moreover, it can increase the time for the manufacture of the product.

Unemployment Issues

Controlling the medical plastic injection mold machines is done primarily by the computers.

The machinery is automatically controlled and fewer workers are required to manufacture the product.

However, where it can be a benefit for lesser labor expenses, it can also be a powerful source of the increasing rate of unemployment. This can be a major led back of the medical plastic injection molding process.

Restricted to thin-walled modules

Medical plastic injection mold can only be used for the manufacture of thin-walled medical components.

Making thick-walled modules will increase the time for the cooling process which, in turn, increases the cost of machinery.

Moreover, thick-walled medical devices may not comprise of the same quality as exhibited by the thin-walled parts.

Therefore, the medical plastic injection molding process may only be limited to manufacture thin-walled high- quality medical components and devices.