The maximum sustained throughput of a single-lane starch molding line is set by the balance between the moisture the starch picks up during molding and how quickly the starch printing and drying/conditioning loop can remove that water. In most sustained operations, the starch printing and drying system becomes the bottleneck before the depositor reaches its mechanical speed limit.
A modern single-depositor mogul moves 15 to 35 trays per minute mechanically; current machines from Winkler und Dünnebier and tna are specified up to about 35 trays per minute. Standard trays run roughly 800 mm wide, jumbo trays about 1,220 mm, with a starch bed 2.5-3.5 cm deep. Sustained throughput on a moisture-removing formula usually runs lower, in the 8 to 16 trays per minute range, set by tray size, cavity count, piece weight, and formula solids.
The reason dewatering rate sets the ceiling is that the loop has to close. Starch comes off the trays carrying the water it pulled from the candy, and the conditioning system must dry it back to its working moisture target, typically 5-7% for gummy and jelly starch. Remove water slower than the line hands it over and starch moisture climbs, cycle after cycle.
Calculating the drying bottleneck
The water load on the starch system is:
Water load (kg/h) = trays/min × moisture pickup per tray (kg) × 60
The theoretical upper limit based on starch dewatering rate is:
Maximum trays/min = starch dryer water-removal capacity (kg/h) ÷ moisture pickup per tray (kg) ÷ 60
Example: at 12 trays/min with 0.6 kg of water handed to the starch per tray, the moisture load is 432 kg/h. If the starch dryer/conditioner is rated for 350 kg/h of water removal, the line is already past its sustainable point. The theoretical upper limit would be 350 ÷ 0.6 = 583 trays/h, or about 9.7 trays/min.
Practical upper limit
Using that mass-balance approach, a single-lane line whose starch conditioning is the weak link sits at a practical sustained ceiling of 10-14 trays/min before conditioning becomes the constraint. Higher sustained rates require more drying capacity, higher deposit solids, or a larger starch conditioning system.
At KorNutra, we treat starch dewatering capacity as the true upper bound for a single-lane line. This keeps the starch bed moisture stable and prevents the starch printing/drying loop from drifting beyond its rated removal rate.
What happens when the dryer is undersized
Push a line past its dewatering capacity and the failure shows up in the starch bed and the finished piece. Starch returns wetter than its 5-7% target, prints less cleanly, and absorbs less water on the next cycle. Pieces release more slowly and trays sit longer in the curing room, where starch-molded gummies routinely spend 24 to 72 hours reaching a final moisture around 14-20%. Finished moisture above spec shortens shelf life and invites sticking during packing. On a contract run with a fixed moisture spec, size the conditioning loop to the water load or raise deposit solids.
The exact number should always be confirmed with a mass balance on the specific formula, tray format, dryer airflow, and target starch moisture.