Sealing Temperature Calculator

Work out sealing temperature instantly with clear inputs, formula shown and shareable results.

About Sealing Temperature Calculator

Heat-seal jaw temperature must exceed the sealant melt point because heat has to conduct through the outer layers within the dwell time. Thicker films and shorter dwell both require a higher jaw setting, which is why the same laminate seals at a much lower temperature on a slow machine than on a fast one.

Formulas

Jaw temperature

Jaw temperature = sealant melt point + thickness allowance + short-dwell allowance

Available dwell

Dwell available = (60 / packs per minute) x jaw closed fraction

Worked example

With the default values below, Sealing Temperature Calculator returns Sealing Jaw Temperature of 118.9. Change any input above and every figure here is recalculated in your browser.

Inputs used

Sealant Layer Melt Pointminimum 1 degrees C: 105 degrees C
Total Film Thicknessminimum 1 micron: 60 micron
Dwell Timeminimum 0.01 seconds: 0.6 seconds
Line Speedminimum 0.1 packs/minute: 60 packs/minute

Results

Sealing Jaw Temperature: 118.9
Allowance For Film Thickness: 9.00
Allowance For Short Dwell: 4.90
Dwell Available At Line Speed: 0.400

Step by step

1Values used
2Jaw temperature
3Available dwell
4Sealing Jaw Temperature= 118.9
5Allowance For Film Thickness= 9.00
6Allowance For Short Dwell= 4.90
7Dwell Available At Line Speed= 0.400

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Seal integrity for food, pharmaceutical and sterile packaging must be validated by seal strength and leak testing against the applicable standard, not set from a calculation alone.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Seal integrity for food, pharmaceutical and sterile packaging must be validated by seal strength and leak testing against the applicable standard, not set from a calculation alone.

Frequently Asked Questions

Why does a hotter jaw not always give a better seal?

Above the sealant's optimum the layer thins and can burn through, and the outer web distorts. Seal strength typically peaks then falls, so a seal window must be established by testing across temperature.

What are the three seal variables?

Temperature, pressure and dwell time. All three interact — increasing pressure or dwell often allows a lower temperature, which is gentler on the film and on product in the seal area.