Abstract: Recycled PET drink bottle flakes were extruded with 30(experiment) and 90(industry) extruders with a same screw structure in order to study the effect of water content of the flakes on the intrinsic viscosity of the product. It showed that the intrinsic viscosity of PET from experiment extruder is lower than that industry one. When water content in flakes was 2.5% and 0.2%, industry extruder resulted intrinsic viscosities of PET product of 0.70 and 0.82 dL/g, respectively. If pyromellitic dianhydride extender was used, the intrinsic viscosity obtained from industry extruder was increased to 0.94 dL/g.

Key words: recycled drink bottle flake, extruder, poly(ethylene terephthalate), reactive extrusion, chain extending reaction