Injection Molding Machine Specifications: What to Look For When Choosing the Right Equipment

2024-07-10 16:40:12

Understanding injection molding machine specifications is your first step to obtaining the best production line efficiency and quality. The key factors to consider when evaluating specifications include the Injection Unit, Clamping Unit, and Power. By understanding these specifications and their significance, you can choose the right machine for your specific production requirements.


Introduction to Injection Molding Machine Specifications

Injection molding machine specifications directly impact the machine's performance and your overall production capabilities. These specifications encompass a range of technical details, from the rate and power of the injection unit to the clamping force and energy efficiency of the machine.


Injection Unit Specifications

The injection unit is responsible for melting, conveying, and injecting the molten plastic material into the mold cavity.


Shot Weight:

Shot weight (g) = Injection volume (V) × ρ (plastic melt density)

The shot weight in the general injection molding machine specifications table is based on PS material (density 0.91g/㎝3). Under low injection requirements, the product uses 20 to 80% of the shot weight of the injection device, and under high requirements, 30 to 60% of the shot weight is used.


Injection Pressure: 

This defines the force applied to the molten material as it is injected into the mold. The injection pressure depends on the plastic material's fluidity, shrinkage rate, and physical properties. The setting of injection pressure should generally be high rather than low. A higher injection pressure is helpful for injection molding of engineering plastics.


Injection Rate: 

The injection rate refers to the maximum volume of molten plastic injected from the nozzle per unit of time and also represents the speed at which the molten plastic passes through the nozzle. Theoretically, the injection rate of products with thinner thickness should be faster, because the plastic will cool rapidly in the mold and lose its fluidity, resulting in insufficient filling. On the contrary, the injection rate requirement of thicker products does not need to be too high.

Item Unit
Screw Dimension mm
Injection Pressure Kg/cm²
Shot Volume cm³
Shot Weight (PS) g or oz
Injection Speed mm/sec
Injection Rate cm³/sec


The Barrel



Clamping Unit Specifications

The clamping unit holds the mold in place and applies the necessary force to keep it closed during injection and cooling.


Clamping Force: 

Clamping force = mold cavity pressure × projected area of ​​the plastic part × viscosity factor of the plastic

This is the force required to keep the mold closed during injection. It needs to be sufficient to counteract the injection pressure. The clamping force of the machine must be greater than the clamping force required by the mold (finished product).


Opening Stroke:

The distance the clamping unit can open to allow for part ejection and mold maintenance. Also refers to the displacement distance from which the movable platen is bent and straightened to the greatest extent by the toggle. Regarding the mold opening stroke, it is better to have it greater than the sum of the sprue length and twice the height of the plastic product.


Tie Bar Distance: 

The length between the four tie bars affects the mold installation space and whether the space can accommodate the size of the mold.

Item Unit
Clamping Force Tons
Tie Bar Distance (HxV) mm
Opening Stroke mm
Mold Thickness mm
Mold Platen (HxV) mm
Ejector Stroke mm
Mold Hole mm


Tie Bar Distance



Power and Efficiency Considerations

Power and efficiency are crucial factors that impact the operational cost and environmental footprint of your injection molding machine.


Servo Motors: 

These can improve energy efficiency and reduce noise levels compared to traditional hydraulic systems. This system enables precise control of pressure and flow in each process, ensuring that the system outputs only as much energy as needed. This approach eliminates excess energy consumption, resulting in significant energy savings.

Item Unit
Servo Motors kW
Machine Dimension (LxWxH) m
Machine Weight Tons



Evaluating the Reputation and Support of the Manufacturer

When investing in injection molding machines, in addition to the technical specifications of the injection molding machine, it is also important to consider the reputation and support of the manufacturer when making your purchasing decision.


When evaluating potential manufacturers, look for companies with a proven track record of producing high-quality, durable machines that are known for their performance and reliability. The quality and reliability of the equipment, as well as the level of customer service and technical support provided, can have a significant impact on the long-term performance and success of your injection molding operations.


If you're ready to invest in a high-quality injection molding machine, or if you need further guidance, contact us at Huarong. Our experts are here to help you find the perfect solution for your manufacturing requirements. Get in touch with us today to learn more!


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