Abstract: The invention relates to a method of producing partially aromatic copolyamides from polymeric esters of aromatic dicarboxylic acids by amidation of the ester groups with diamines, removal of the split-off alcohols or diols and after-condensation of the low-molecular precondensates as well as by the following compounding to polyamide molding materials.

Abstract: 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.

Abstract: A planetary gear for a multiple-screw extruder includes a circular stationary housing having internal teeth, a sun wheel formed from at least one toothed portion of a spindle, and a plurality of main planet wheels formed from at least one toothed free end of a plurality of screws and arranged in a circle. The plurality of main planet wheels are spaced from one another, from the sun wheel and from the internal housing teeth. A plurality of internal and external intermediate planet wheels are arranged between the sun wheel and the main planet wheels and between the main planet wheels and the internal housing teeth, respectively.