Plastic Injection Molders

You have different processes to choose from when designing a product that requires molded plastic parts. Injection molding is a popular process to achieve cost-effective and high-quality plastic parts.  

Injection molding produces parts in large volumes. The process involves using high temperature and pressure to fill the interior with liquid polymers or molten plastic resin. 

The mold materials are then cooled to form plastic parts. The process is versatile and can produce numerous parts for a wide range of applications. 

Components Of An Injection Molding Machine

The major components include but not limited to: 


Here is where you insert the material for the molding process.

Screw motion 

It pushes the molten material in a forward direction.


The heater works to melt the material. It is used to increase the system temperature to prepare the product.

Clamp Plates

Clamp plates are used to attach mold halves with molding platens. While other machines hold the mold onto the platen with magnets, mold clamps use large bolts to keep them in place.


Cavities are sections of the mold where the main part is formed. However, there are a certain number of cavitation’s allowed because molds must be balanced.


The nozzle is where liquified plastic passes through. It sits against a surface on the mold named the sprue bushing, which helps center the nozzle to the mold.

Cooling System

Molten plastic is injected hot and cooled using a cooling system. Working fluid is typically liquid, but oil can be used in high-temperature applications. 

Guide pillars/bushings

You must be appropriately aligned cavity and core mold halves during mold close using guide bushings (or sleeves) and guide pins (or pillars).

Ejector System

Ejector System is a set of bars or pins used to push parts of the core.

Ejector Plate 

The ejector pins are located on an ejector plate. The forward movement of the ejector plate enables the pins to move forward, pushing the part off the core. 

Injection Molding Process

The molten material is poured into the hopper using a feeding device. The molten material goes under the action of gravity into the cylinder. A circumferential heater found on the barrel is used to melt the material. 

The molten material is introduced or injected into a closed mold attached to the other side of the barrel. Molding material moves forward continuously by the rotating screw. The hydraulic system applies pressure. The parts manufactured are cooled after the whole process is completed. Then the mold is open, and some ejectors are used to remove or extract the part without damage. 

Partner With Apollo Optical Systems 

Understanding injection molding basics is helpful if you plan to introduce a new product to the market. At Apollo Optical Systems, we are a full-service injection molding manufacturer in New York, serving a wide range of clients. Our experts are ready to help you by providing the best injection molding services. 

Contact us today at 585-272-6170 to learn more about our plastic injection molders’ capabilities.

Plastic Injection Molders

Apollo Optical Systems

(585) 272-6170

Plastic Injection Molders

925 John St

West Henrietta NY 14586 US

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