It is important that the dryer have the correct design requirements for the plastic resin to be processed. Eastar copolyester 6763 should be dried at a maximum temperature of 65 degrees C (150 degrees F). Care should be taken to obtain a dryer that can be accurately controlled to deliver air at a temperature of 65 degrees C (150 degrees F) as some dryers tend to cycle uncontrollably hotter. Higher temperatures will cause the pellets to stick in the hopper. An aftercooler should be used to help control the temperature of the air leaving the desiccant bed. An inlet temperature gauge is a useful addition to the drying hopper.

A desiccant dryer is required. This type dryer provides drying air having a dew point of -30 degrees C (-20 degrees F) or lower. A dew point monitor, an option available on modern dryers, is worth the small additional cost.

The drying hopper should be large enough to allow 4 hours of drying time for the pellets during steady state extruder operation. A good drying hopper has a screen and cone system in the bottom to ensure uniform airflow through the pellet bed. It is also designed to provide an even flow of pellets from top to bottom (plug flow) and has an air-lock loading system. Insulated hoppers should be used to maintain the pellet bed at the inlet air temperature.

Dryers are specified according to their capacity to deliver a given volume of air in a given amount of time. A good dryer design criterion allows 0.062 m3/min per kg/h (1.0 cfm per lb/h) of material to be extruded. For example, if 45.4 kg/h (100 lb/h) of material is to be extruded, a minimum blower capacity of 2.8 m3/min (100 cfm) is used. A dryer with a blower capacity of 2.8 m3/min (100 cfm) should be considered the smallest size for any use, since smaller blowers may not have sufficient airflow to prevent excessive heat losses.