Drying
To prevent hydrolytic degradation, the waste fibers have been dried in 120°C in 60 min with a MotanÒ dehumidifier. The dehumidifier was designed to dry granules, for that reason during output bridging happened and throat blocked. The lids are opened and wastes are discharged, during that time wastes were regained moisture inevitably. Dried waste samples were stored in air-blocked alu- minum covered bags with silica gels.
The moisture amount of dried waste material was 0.0311% ± 0.005 after nine measurements from a total 100 kg. The measurements have been carried out according to LurgiÒ analytical procedure. It is well known that, the moisture amount in original granules is less than 30 ppm for fiber production. It was thought that the moisture limit could be in- creased in re-extrusion because of degassing zones and moisture amount could be varied due to appli- cation fields of the final product and operation conditions.