Does a small batch of resin dry faster?

No. Drying time is time at temperature and dew point, set by the resin supplier, so any charge needs the full time. A smaller charge only means less resin is ready when it is done.

When does the supplier's drying time start counting?

When the resin reaches drying temperature at the specified dew point. Conair notes suppliers specify time at the proper temperature and dew point, so a cold charge first needs its start-up.

My resin sat in an open box. Is the datasheet time enough?

Possibly not. Novatec reports that nylon which dries in 3 to 4 hours out of the bag can take 24 hours once saturated. Measure moisture and enter a longer drying time if needed.

Can the press run before the whole lot is dry?

Yes. Once the first charge is dry, the press draws from the hopper while the loader tops it up. Keep the draw at or below the steady limit. Wittmann's pre-drying timer runs from switch-on and blocks conveying to the press, so set it to at least the headline time.

Injection Molding calculator

Resin Drying Time Calculator

Find when the first charge in your drying hopper is ready to mold after a cold start. Compare it with the lead time you plan before the first shot.

What this calculator does

When the first charge of resin is dry after a cold dryer start, and whether your lead time covers it.

Formula used

Time to first dry charge = dryer start-up time + supplier drying time
Spare time = planned lead time − time to first dry charge
Resin per charge (kg) = hopper working volume × bulk density
Charges for the lot = lot ÷ resin per charge, rounded up; minimum whole lot = start-up + charges × drying time
Steady draw limit (kg/hr) = resin per charge ÷ drying time

Inputs explained

Supplier Drying Time: Hours at drying temperature and dew point, from the resin datasheet.
Dryer Start-Up Time: Cold start until the charge reaches drying temperature, timed on your dryer.
Planned Dryer Lead Time: Hours between starting the dryer and the job's first shot.
Resin Lot for the Job: All the resin this job will use.
Drying Hopper Working Volume: Volume below the loader's fill level, from the hopper spec sheet.
Resin Bulk Density: Pellet bulk density from the resin or dryer maker's table.

How to use the result

Best suited to back-scheduling a dryer start before a shift, planning a material change on one press.
Datasheet drying times assume resin as shipped; resin left open may need far longer. Start-up time varies with ambient temperature and desiccant condition.

Current U.S. benchmarks

The producer price index for plastic resins and materials stands at 280.569 (BLS, Aug 2026), up 6.6% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The U.S. has 9,635 plastics product manufacturing establishments employing about 677,302 workers (Census County Business Patterns, 2023).

Common questions

Does a small batch of resin dry faster? No. Drying time is time at temperature and dew point, set by the resin supplier, so any charge needs the full time. A smaller charge only means less resin is ready when it is done.
When does the supplier's drying time start counting? When the resin reaches drying temperature at the specified dew point. Conair notes suppliers specify time at the proper temperature and dew point, so a cold charge first needs its start-up.
My resin sat in an open box. Is the datasheet time enough? Possibly not. Novatec reports that nylon which dries in 3 to 4 hours out of the bag can take 24 hours once saturated. Measure moisture and enter a longer drying time if needed.
Can the press run before the whole lot is dry? Yes. Once the first charge is dry, the press draws from the hopper while the loader tops it up. Keep the draw at or below the steady limit. Wittmann's pre-drying timer runs from switch-on and blocks conveying to the press, so set it to at least the headline time.

Last reviewed 2026-10-01.