| abstract |
The invention relates to a process for the production of bottle preforms from the melt of polyethylene terephthalate and / or its copolyesters, wherein in the continuous stream or partial stream (1) of the polyester melt from a polycondensation, which has an intrinsic viscosity between 0.5 and 0. 75 dℓ / g, optionally inert gas (2) is introduced, the melt then under vacuum (4) in a screw post-condensation reactor (3) to an intrinsic viscosity of 0.75 to 0.95 dℓ / g and to an acetaldehyde content Driven below 10 ppm and then passed into an injection molding tool (7) and processed into preforms. |