Condensation injection molding process for producing bottle preforms of polyethylene terephthalate and/or its copolyesters and resultant preforms

摘要

A process for producing bottle preforms from the melt of polyethylene terephthalate and/or its copolyesters, includes selectively introducing an inert gas into the continuous flow or partial flow of the polyester melt from a poly-condensation having an intrinsic viscosity between 0.5 and 0.75 dl/g, subsequently bringing the melt to an acetaldehyde content below 10 ppm in a melt after-condensation reactor and to an intrinsic viscosity of 0.75 to 0.95 dl/g and thereafter guiding the melt into an injection molding tool and processing same.