Drying and Crystallization of PET to 50 ppm

The challenge.

Processing of PET material with initial moistures of up to 13,000 ppm (bottle flakes) or 6,000 ppm (foil flakes) for processing on single-screw extruders without vacuum degassing.

The goal.

Achieve moisture content of 50 ppm.
Prevent sticking and clumping of the material in the extruder intake and limiting the hydrolytic degradation of the IV value.

Our process.

Recycled material (virgin or blend) is recrystallized in a continuous IRD in under 15 minutes, then uniformly heated to 175 °C and dried to about 300 ppm. Subsequently, the material is transferred to a conventional hot air dryer for further moisture reduction to 50 ppm (about 60 minutes).

Your benefits.

  • Crystallization and drying in one process step
  • Approximately 75 % dwell time reduction
  • About 35 % energy saving
  • No separation of blends of recycled material and virgin material
  • Capacities from 100 kg/h to 2.5 t/h economically feasible
  • Return on Investment: < 15 months