Crystallizers
Technically, crystallizers are not dryers. They are used to convert PET from an amorphous, back to a crystalline state for reprocessing.
The crystallizer consists of an insulated hopper with an agitator driven by a gear motor and a heater/blower. Amorphous material is loaded into the top of the hopper and is heated to about 180˚ F. while being agitated to prevent agglomeration.
The crystallizing process in a typical crystallizer can be and must be monitored carefully for success. Crystallization may occur in a few minutes up to about an hour, depending on the properties of the material being crystallized. Upon completion, the re-crystallized material, discharged from the base of the hopper may then be transported to a drying hopper where it is dried by a dual bed or desiccant wheel drying system. Then it can be processed into new products.
NOTE: The infrared drying system is a new technology gaining rapid acceptance for crystallizing and drying PET. You can accomplish both operations in one step in one hour with greatly reduced energy usage.
Types of Resin Drying Systems
Silo Dehumidification/ Hot Air Dryers
What is a silo dehumidifier and how does it work and compare with other resin drying systems?
The principle of compressing air in factories for power tools and other high-pressure uses has a side benefit for the world of resin drying.
What is a membrane resin dryer and how does it compare to a compressed air dryer without a membrane?
What is a vacuum resin dryer and how does it draw moisture away from plastic pellets in vacuum processing?
Dual Bed (also called Twin Tower) dryers used to be the most commonly purchased type of resin dryer. A look at why, and where the technology has progressed.
The advantages of desiccant wheel dryers include operating at a low temperature, which is important for preventing thermal degradation of the resin.
Technically, crystallizers are not dryers. They are used to convert PET from an amorphous, back to a crystalline state for re-processing.
Drying Hoppers for Plastic Resins
Drying hoppers are part of most drying systems. At a glance, they look much the same, but there are certain features you should look for.
What are the benefits of gas-fired process heaters for drying plastic resins?
Resin drying machines that can be moved from machine to machine within a plastics processing plant have advantages and disadvantages over a central drying system.
Properly designed Central Drying Assemblies are easily connected together to save installation costs.
PET Energy-Saving Drying Systems
Learn about the keys to drying PET efficiently while saving space and energy.