How long a PU adhesive takes to cure depends on the grade, the temperature and — for moisture-cure types — the humidity route you give it. This lookup shows the actual cure figures from our TDS sheets for each grade and process route. Pick a grade to see its numbers; every value below comes straight from the product's technical data sheet, not from interpolation.
Why There Is No Universal Cure-Time Curve
Cure chemistry differs by grade, so temperature affects each one differently:
- Moisture-cure 1K grades (MPU-20, the rebond binders) need water to react. Warmth helps, but on a dry winter line the limiting factor is humidity — which is why a light water mist or steam shortens the cure far more than a few degrees of air temperature.
- 2K grades (PU-50) carry their own reaction partner. Heat accelerates them on both ends: cure finishes sooner, but pot life shrinks too. The number to manage on the line is the pot life, not the final cure.
That is also why we publish discrete tested figures rather than a smooth time-temperature curve: the TDS values above are what was actually measured.
Reading the Numbers for Your Line
- Match open/pot time to your lay-up speed first. A cure you can shorten with steam or mist; an exceeded open time you cannot fix.
- Check your shop temperature against the grade's floor. The rebond binders want 20°C minimum; below it, plan the steam route.
- Plan de-mould and handling around the cure figure, then add aging. Handling strength and full cure are different points — rebond blocks want ~24 h before cutting regardless of route.
FAQ
Can I speed up a 1K PU cure with heat alone?
Heat without moisture does little for a moisture-cure grade. Steam (heat + moisture together) is the effective accelerator — 120°C steam takes the rebond binders from hours to 10–14 minutes.
Does cold weather stop 2K PU from curing?
PU-50 cures at room temperature; in a cold shop the reaction slows but proceeds. For service at extreme cold the relevant evidence is tested joint strength — PU-50 is rated ≥12 MPa at −137°C.
My grade is not listed — where are its figures?
Each product page carries its own TDS. For sandwich-panel consumption planning, see the adhesive coverage calculator; for anything else, contact us and we will send the TDS for your grade.
Related guides: how to reduce polyurethane curing time · PU adhesive in low-temperature environments · rebonded foam application guide.