| 摘要 |
<p>A method for the solid state polymerization of PET, which comprises the steps of subjecting finely divided PET material, having an intrinsic viscosity comprised between 0,60 and 0,80 dl/g to heating in an inert atmosphere while it flows in the form of a thin, turbulent, dynamic layer in contact -with a wall heated to at least 200°C, obtaining a PET material with an average intrinsic viscosity higher or equal to 0,85 dl/g; advantageously, the above method is carried out with the aid of a turbo-heater (T) comprising a cylindrical tubular body (1) equipped with a heating jacket (4), with inlet and outlet openings (5, 6) and with a bladed rotor (7) rotatably supported thereinside.</p> |
