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What are the Different Powers of Injection Molding Machines?

Generally speaking, injection molding machine manufacturers produce injection molding machines. From the energy consumption can choose a quantitative pump injection molding machine, variable pump injection molding machine, servo energy-saving injection molding machine, and all-electric injection molding machine.

Currently, the power configuration of the injection molding machine is similar—the same system of the injection molding machine factory has no big difference. The biggest difference is mostly focused on the use of power size. Power can provide a higher range of parameters and clamping force control. 

Still, such a configuration of the injection molding machine is more likely to lead to oil leakage, and mechanical failure, the need for more layers of oil pipes and mechanical rigidity with the injection molding machine cost will also partly rise.

Injection molding machine injection pressure selection

  • The injection pressure of the injection molding machine Pi=P*A*s/Ao
  • P=system working pressure (MPa)
  • A = effective cross-sectional area of injection piston (cm2)
  • s=Number of injection cylinders (generally 2)
  • Ao = cross-sectional area of the screw or barrel plunger (cm2)

From the above formula, we can see that the higher the injection pressure required for the product, such as some engineering materials, the optimal method is to increase the system pressure or increase the cylinder area and increase the number of injection cylinders (this is rarely), there is also the screw diameter becomes smaller.

Therefore, injection molding machine manufacturers to our choice of injection molding machine screw, large diameter screw injection pressure relatively low, suitable for general plastic processing. The smaller the diameter of the screw, the higher the injection pressure, and the more suitable for processing engineering plastics. When we want to use higher injection pressure, the diameter of the injection cylinder should be bigger to meet the requirement. Single-cylinder injection pressure is not as high as double-cylinder injection pressure.

Usually, because of the space limitation of the injection molding machine, the diameter of the injection piston rod cannot be increased indefinitely, and the diameter of the screw cannot be reduced indefinitely, so more injection cylinders cannot guarantee the balance of injection, so generally only two injection cylinders can be selected. Suppose higher injection pressure is needed for processing products and materials. 

In that case, it is more often achieved by increasing the system pressure, which used to be 140MPa for quantitative pump injection molding machines, but nowadays 175MPa for injection moulding machines, and 220MPa for foreign injection moulding machines. The servo motor of an all-electric injection molding machine can provide more than 450MPa injection pressure, which has natural advantages in precision molding.

When choosing an injection molding machine, engineering materials and precision parts should choose an injection molding machine with high injection pressure as much as possible.

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