PROCESS FOR GRANULATING POWDERS OF THERMOPLASTIC POLYMERS UNDER IMPROVED ECONOMIC CONDITIONS

摘要

In a process for granulating thermoplastic polymers, in particular thermoplastic polyolefins, the polymer powder prepared in the polymerization reactor is introduced into an extruder, melted and homogenized in the extruder, then pressed through an extrusion die and granulated. According to the invention, an organic solvent or suspension medium is added to the polymer powder in an amount in the range from 0.001 to 20 % by weight, prior to introduction into the extruder. The invention is particularly useful for granulating polyethylene or polypropylene, thereby increasing the polymer throughput at constant energy consumption or decreasing the energy consumption at constant polymer throughput.