Automatic modular systems offer up to 10,000 - 12,000 kg/h capacity for stable and gentle drying, all without requiring either compressed air or cooling water. Good quality process in drying plastic granulate materials involves management and control of the 10 factors influencing the drying process: type of material, granule size, bulk density, temperature, dew point, residence time, specific airflow, initial air moisture content, final residual air moisture content, viscosity.Drying effectiveness is also determined by the speed of migration of water molecules from centre of granules to the outer surface. The lower the dew point, the better the final result. This will be better also as it concerns the final moisture that will be obtained in less time. Ability of air to absorb and remove the moisture depends on how low the air dew point is and the moisture having a low dew point, the temperature at which it condenses on relatively cool surfaces.
Moreover, for the treatment of highly hygroscopic polymers, the following factors cover a main role:
1. constant performance
2. automatic variable airflow
3. high performance with constant dew point at –65° C
All of these factors have been taken into account by Italian plastics ancillary equipment producer MORETTO in the design of a new drying system for plastics, particularly for the PET treatment.
By means of zeolite, a mineral of volcanic origin, as molecular sieves, a lower energy consumption compared to the conventional dryers is reached. This kind of drying is also the basis of the new MORETTO project dedicated to the PET treatment. It is the FLOWMAX system which combines efficaciously the technology of the new X MAX dryers and the Flowmatik device.
