In the hopper, the drying units force hot dehumidified air through the plastic granule by way of a closed air circulating system. The moisture is removed by the sieve desiccant, which traps the moisture molecules. The dry air is then heated to a preset temperature and delivered to the material in the insulated hopper.
The majority of water is absorbed in the initial contact with the desiccant bed. When the bed becomes saturated, it is regenerated by heating to more than 500 degrees F (290 degrees C), purging itself of moisture. Properly maintained dryer systems give consistently dry resin, higher yields, and improved stream time, which can yield greater profits. Desiccants should be replaced every two years, and dryer filters should be checked and cleaned once each shift to insure adequate air flow to the bed.