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Garment Dryers in Detail

(October 2010) posted on Tue Sep 21, 2010

Find out about the differences between IR and hot-air dryers and discover which features might be most useful to your operation.

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By Sylve J.D. Ericsson

Constant temperature Air temperature is kept constant thanks to the recirculation of the forced hot air over the heater. Garments and inks are heated and dried very effectively without any risk for over heating or scorching. The garment does not influence the drying performance and ink thickness, which can be easily fine-tuned by adjusting the drying/retention time. The position of the temperature sensor may differ according to dryer design, and the air temperature where the sensor is placed may not be same as the air temperature at conveyor level. Run a temperature probe on the conveyor through the dryer and compensate for any discrepancy between the dryer’s temperature setting and the actual reading from the probe.

Gas/electric consumption The recirculation of hot air enables even very large dryers to consume power modestly—and if gas is available, this often even more favorable.

Airflow/nozzle system The airflow and nozzle system is the most important factor for dependable drying performance. The more air that is recirculated and blown over the printed garment, the more effective the heat-transfer rate—that is, how fast the air can heat up the ink to its curing temperature. This is especially important for water-based inks, where greater air volume and higher air velocity are very influential for the dryer’s ability to drive out the water in the shortest possible time and prepare for the second drying phase: heating up the ink to the point of cross linking.

Air supply A large, high-capacity, high-performance blower is a must to ensure the proper supply of air to the dryer hood. The dryer hood must be large enough to hold and pressurize the air for even distribution across and along the hood. The pressurized air is then ducted through specially formed, high-speed nozzles that accelerate and direct the hot air onto the garment. Each nozzle acts like a mini dryer, and each one is identical in its performance to guarantee even distribution of the air flow and temperature across the drying area without creating any hot spots or uncontrolled, turbulent areas.

Internal components Drying water-based inks causes the release of water vapor into the dryer. In time, this will result in corrosion and rust that will severely damage the dryer. To prevent such corrosion, the dryer interior must be fabricated of stainless steel or aluminized sheet metal. Check the specifications of any dryer before introducing water-based inks to it.


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