Injection Molding worked example

Injection Pressure with hydraulic system pressure during injection of 5,000 psi: a worked example

This scenario runs the injection pressure calculation on the strong side: hydraulic system pressure during injection of 5,000 psi, with every other input held at its documented default. Use this to verify that your press can deliver enough plastic pressure to fill the mold, set initial process parameters, or compare actual vs. available pressure.

The inputs for this scenario

  • Hydraulic system pressure during injection: 5,000 psi (raised for this scenario; the documented default is 2,000)
  • Intensification ratio (cylinder/screw area ratio): 10 :1 (unchanged)
  • Pressure loss factor: 0.92 x (unchanged)

Working through the calculation

  • Applying the documented formula (Plastic pressure = Hydraulic pressure x Intensification ratio x Loss factor) to the inputs above produces each figure below.
  • At this operating point the engine returns 46,000 psi for result, the number this scenario is built around.
  • At this operating point the engine returns 46,000 value for gross pressure (hydraulic x ratio).
  • At this operating point the engine returns 1 x for multiplier.
  • At this operating point the engine returns 50,000 value for factor a x b.

How this compares with the baseline

  • Against the tool's baseline example, where hydraulic system pressure during injection sits at 2,000 psi and the headline result is 18,400 psi, this scenario comes in 150% above the baseline at 46,000 psi.
  • Use it when selecting a press for a new tool, transferring a mold between machines, or diagnosing short shots that may be pressure-limited rather than temperature- or speed-related. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Result: 46,000 psi (headline result)
  • Gross pressure (hydraulic x ratio): 46,000 value
  • Multiplier: 1 x
  • Factor A x B: 50,000 value

Run it with your numbers

  • Every input above is editable in the live Injection Pressure calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.