What are the factors affecting the dryer?
The dry hot air transfers heat to the particles in the drying silo, removes moisture from the surface of the particles, and then sends moisture back into the dryer. Therefore, there must be enough air flow to heat the resin to the drying temperature and maintain the temperature for a certain period of time.
In the air around the particles, the absorption of heat and the diffusion of water molecules to the surface of the particles take a certain amount of time. Therefore, the resin supplier shall specify the time required for the effective drying of a material at the proper temperature and dew point.
In the dryer, the wet air is removed first so that a very low residual moisture (dew point) is contained. The relative humidity is then lowered by heating the air. At this point, the steam pressure of the dry air is low. By heating, water molecules in the particles escape from the bond force and diffuse to the air around the particles.
Drying temperature, heat is the key to opening up the force between water molecules and hygroscopic polymers. When higher than a certain temperature, the gravitational attraction between water molecules and polymer chains will be greatly reduced, and water vapor will be taken away by dry air
