Residence Time Calculator

Estimate barrel residence time from barrel melt mass, shot mass, and cycle time. Use this as a documented planning estimate, then validate it against the actual machine, mold, resin, and process.

Formula and method

Residence time = barrel mass / (shot mass x cycles per minute).

Use a documented barrel mass at operating conditions and the complete shot, including runner where applicable.

Inputs and units

Use controlled records, CAD, measured production data, the exact resin data sheet, or machine-maker specifications. Keep the material and time basis with the result.

Worked example

1.2 kg with a 180 g shot every 30 s gives 3.33 min.

What the result supports

This result is a first-pass screen for injection unit planning. Use it to identify the next record or engineering check, not as a release decision.

Sanity check

Check the unit basis and whether all quantities describe the same cavity, shot, machine, or production window before comparing values.

Important limitation

Actual residence-time distribution, screw design, and material stability require supplier and machine review.

Reference: ENGEL: machine data example.

Next calculation

Screw Stroke Calculator · Injection Unit Utilization Calculator

FAQ

What must be checked after using residence time calculator?

Retain the input source and compare this estimate with the applicable machine, mold, supplier, or production record before relying on it.