PET system:PET Crystallizing Drying System

No conglomeration and crystallization unevenness by constant velocity gas flow

Piston flow of resin chips is ensured by hopper system so that it avoids conglomeration and crystallization unevenness.


PET Molding Crystallization Drying

System Features

  • 1. Dummy pellets are unnecessary at the start of operation.
  • 2. There is no conglomeration and crystallization unevenness.
  • 3. Check of the hopper inside is easy.
  • 4. Operation with LCD touch panel system.


We adopted hopper system in all the process of crystallization so that piston flow of resin chips is ensured. As for the hopper structure of our system, the diamond shaped core is provided at the lower cone section of the hopper, so that circular gas flow occurs between the lower cone section and the diamond shaped core, and resin chips rise (bulk density decreases).

Consequently gas portions increase, and gas resistance becomes small so process gas can flow at constant velocity against sectional area. With the above effect, polymer resin is not damaged and can be moved down with piston flow (making fluctuation range of retention time of resin as small as possible to get uniform crystallization). Homogeneous gas flow rate is that surface gas velocity is 0.6 m/s, or gas flow rate is 0.06Nm3/

Fine Particles and Fine Chips

Fine particles, pull ups and the like may cause excessive heating, abnormal high melting point, or (appearance) feed fault of an injection machine. Difference of heat history for some area may cause inferior luster on formed products, or opaque area in fine portion. The rotation speed of the agitator of the crystallization hopper is low as 1.5 to 2.5 rpm, so the growth of the fine particles and pull ups are little. And the fine particles are discharged together with gas flow and collected in a filter.

Thermal Degradation, Oxidative Degradation, and Hydrolysis

Concerning thermal degradation, oxidative degradation, and hydrolysis of PET resin, it is known that with the same temperature, oxidative degradation advances at approximately twice the rate of thermal degradation, and hydrolysis advances at approximately 5,000 times the rate of oxidative degradation. Degradation rate of PET resin is as follows. These three degradation occur at the same time in parallel, so that degradation process of PET is extremely complicated

"Thermal Degradation" << "Oxidative Degradation" << "Hydrolysis"


  • 1. Please consult us when crystallization drying process is necessary.Our wealth of experience and advanced technology cultivated in spinning industry are reflected in our system.
  • 2. We adopt your request of consultation about solid phase polymerization system of crushed flake materials or repelletized materials. We have a test machine in our plant. Please inform us when test is necessary.