How do you calculate cure die dwell run time?

Divide the profile length by the cure-limited line speed to get the base time, then add the safety allowance. For 120 units at a rate of 12 with a 10% allowance, the base time is 10 hr and the adjusted time is 11 hr.

What sets the maximum safe line speed in pultrusion?

The resin's cure kinetics and the die's temperature zones. The profile must dwell long enough to fully cross-link before exiting. Thick sections and slower resins like epoxy demand more dwell, which caps line speed and lengthens run time.

Why add a safety allowance to the cure run time?

Base time assumes an instant start at full speed. Real runs need die warm-up, first-article sampling, and a cure margin. The 10% allowance here turns a 10-hour base into an 11-hour adjusted plan you can actually schedule to.

What happens if cure dwell is too short?

The profile exits under-cured: soft surface, blistering, poor mechanical properties, and possible internal cracking from residual exotherm. Slowing the line to restore dwell is the fix, which is why cure sets the rate ceiling.

How do I fit a run into a single shift?

Compare the adjusted run time to your shift hours. If the 11-hour adjusted time exceeds an 8-hour shift, either split the run, raise die temperature to allow faster cure, or plan the overflow into a second shift.

Cure die dwell vs pull speed, how are they related?

They are inverses of the same limit. Dwell is time in the die; pull speed is how fast you move through it. A faster pull shortens dwell, so cure kinetics set both the maximum pull speed and the minimum dwell simultaneously.

Pultrusion & Continuous Composite Profiles calculator

Cure Die Dwell Calculator

Cure die dwell is the time reinforcement spends in the heated forming die reaching full cross-link, and it caps how fast a pultrusion line can safely run. Push the line rate too high and dwell drops below what the resin's cure kinetics need, so parts exit soft, blistered, or under-cured. This calculator turns a run's length and the cure-limited line speed into a base run time, then adds a safety allowance for warm-up, sampling, and the margin you keep on cure. Engineers use it to schedule the die and confirm a run fits the shift.

What this calculator does

Cure die dwell is the time reinforcement spends in the heated forming die reaching full cross-link, and it caps how fast a pultrusion line can safely run.
Use it when cure die dwell in pultrusion and continuous composite profiles needs a defensible run time before a quote goes out.
It computes the run time in hours to cure a given profile length at a cure-limited line speed, then applies a safety allowance to give an adjusted time.

Formula used

Base cure die dwell time = required work ÷ processing rate
Adjusted time = base time × allowance factor

Inputs explained

Linear feet of profile to cure:
Cure line speed through the die:
Cure schedule safety allowance:

How to use the result

Use it when scheduling a run against die temperature and cure kinetics, or checking whether a length fits within the available shift hours.
It assumes a steady cure line speed; die warm-up, mid-run speed changes, and off-spec restarts are only approximated by the flat allowance percentage.

Current U.S. benchmarks

The producer price index for plastic resins and materials stands at 319.371 (BLS, May 2026), up 19.5% from a year earlier. Quotes priced off last quarter's material cost miss this move.

Common questions

How do you calculate cure die dwell run time? Divide the profile length by the cure-limited line speed to get the base time, then add the safety allowance. For 120 units at a rate of 12 with a 10% allowance, the base time is 10 hr and the adjusted time is 11 hr.
What sets the maximum safe line speed in pultrusion? The resin's cure kinetics and the die's temperature zones. The profile must dwell long enough to fully cross-link before exiting. Thick sections and slower resins like epoxy demand more dwell, which caps line speed and lengthens run time.
Why add a safety allowance to the cure run time? Base time assumes an instant start at full speed. Real runs need die warm-up, first-article sampling, and a cure margin. The 10% allowance here turns a 10-hour base into an 11-hour adjusted plan you can actually schedule to.
What happens if cure dwell is too short? The profile exits under-cured: soft surface, blistering, poor mechanical properties, and possible internal cracking from residual exotherm. Slowing the line to restore dwell is the fix, which is why cure sets the rate ceiling.
How do I fit a run into a single shift? Compare the adjusted run time to your shift hours. If the 11-hour adjusted time exceeds an 8-hour shift, either split the run, raise die temperature to allow faster cure, or plan the overflow into a second shift.

Last reviewed 2026-05-12.