| 摘要 |
Process for the production of granules of expandable thermoplastic polymers by means of extrusion, which comprises: i) melting the polymer in a single- or multi-screw extruder ( 2 ); ii) incorporating an expanding agent in the polymer in the molten state; iii) granulating the polymer thus obtained in a device comprising a die ( 111 ), containing a series of ducts ( 115 ) made of a material having a high thermal conductivity ( 114 ), a cutting chamber ( 118 ) containing a set of hydraulic nozzles and a cutting system equipped with a set of knives ( 215 ) with a cutting edge which is radial with respect to the surface of the die; iv) annealing the granules thus obtained; v) cooling the annealed granules to room temperature.
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