Strand granulating method

The procedure for the production of granulate grain from thermoplastic polyester or copolyester of a polyester melt by a strand granulator, comprises supplying the polyester melt to nozzle (1) of the strand granulator, bringing strands (2) emerging from the nozzle over a discharging line to a granulation device with discharge roller (5), crystallizing the granulate grain in a crystallization chamber by a process gas stream directly on a granulation of the strand in a granulation device (4), and pre-condensing the produced granulate grain. The procedure for the production of granulate grain from thermoplastic polyester or copolyester of a polyester melt by a strand granulator, comprises supplying the polyester melt to nozzle (1) of the strand granulator, bringing strands (2) emerging from the nozzle over a discharging line to a granulation device with discharge roller (5), crystallizing the granulate grain in a crystallization chamber by a process gas stream directly on a granulation of the strand in a granulation device (4), and pre-condensing the produced granulate grain. A strand withdrawal speed (V a b) is adjusted over the discharge roller. The discharge of the strand from the nozzle is carried out with a discharge speed (V a u s) of 110 m/min. The ratio of the discharge speed is adjusted through the surface (f) of the nozzle opening of the respective nozzle (V a u s/f) so that the condition of V a u s/f>= 30 m/(minx mm 2>) prepossesses. The strands emerging from the nozzles are brought directly at the nozzle discharge into a cooling fluid contact over an air gap, whose length is adjusted to 2 mm. The stretching (V = (V a b-V a u s/V a u s) of the resigning strand is adjusted during discharging the strand so that the condition V= 0 prepossesses through adjusting the strand withdrawal speed and/or the discharge speed. The discharge speed is adjusted at 80 m/min to maximum 350 m/min. The surface of the nozzle opening is adjusted to less than 4 mm 2>. The diameter (d) and/or the length (l) of the nozzle opening are adjusted so that the ratio l/d prepossesses the condition l/d=0.3. The nozzle openings are formed so that a strong cross-sectional narrowing takes place directly before the nozzle discharge. The ratio area F at the inlet into the nozzle hole is measured by a place that exists itself around the distance (L) before the discharge of the nozzle opening. The distance (L) is less than 8, which is adjusted through the surface (f) of the nozzle opening