From flakes to the end product in a single process step. The key components of the system include a vacuum reactor which is connected directly to a single-screw extruder. Thanks to the ingenious function of the mixers in the vacuum reactor they feature three ultra-efficient function zones which interact perfectly with each other to decontaminate and predry the PET material perfectly already BEFORE extrusion:

Zone 1 is responsible for the removal of the outer moisture of the PET flakes. The amorphous, washed flakes which enter Zone 1 via a vacuum sluice, still have extremely varying external moisture (between 0.5 and 1%). This is eliminated at around 20°C under vacuum through the reduced vaporisation point (the inner moisture here is still constant at around 0.3%).

In zone 2 the temperature rises from 20°C to 190°C. Thanks to the constantly rising temperature the polymer structure opens up and the process for the removal of the migration substances and the internal moisture from the flakes begins.

Zone 3: the process of flake decontamination and removal process unfolds with full effect. The material moves layer by layer in the direction of the single-screw extruder during the exactly defined residence time. With very low residual moisture of under 0.05% the clean, perfectly prepared material enters the intake zone of the extruder.

This material transfer takes place under high vacuum. As a result no additional degassing ports are required on the extruder itself. This means that VACUREMA? technology drastically reduces the length of the extruder, reduces its energy consumption, improves the colour values (b value) of the processed material and keeps AA values to a very low level. Moreover, the strong homogenisation performance of the extruder plays a significant part in turning the different input IV values into a stable output IV value.

In the downstream high-performance fine filter the material is filtered with a 32 μm mesh screen width. The filter system is equipped with a patented fully automatic self-cleaning system that enables long filter service life. The melt is now ready and can be transferred directly to the downstream unit. This is where the desired end products – thermoforming sheet, preforms, strapping or fibres – are produced inline without the detour of pelletising. As an option, amorphous or crystalline pellets can also be produced instead of the end products.