The invention belongs to the technical field of
polypropylene foamed beads, and particularly relates to a preparation method of high-multiplying-power electroconductive
polypropylene foamed beads. Thepreparation method includes following steps: A, mixing
polypropylene resin and electrocconductive
carbon black according to a certain proportion, and
processing through double-screw
extrusion to obtain first electroconductive
masterbatch; B, mixing polypropylene resin with electroconductive filler according to a certain proportion, and
processing through double-screw
extrusion to obtain second electroconductive
masterbatch; C, melt-blending polypropylene resin, a nucleating agent, the first electroconductive
masterbatch and the second electroconductive masterbatch to obtain polypropylene particles; D, putting the polypropylene particles obtained in the step C, a dispersion medium and a dispersant together into a foaming reaction kettle, feeding a foamer into the reaction kettle, heating,pressurizing, and depressurizing polypropylene foamed beads when reaching set
temperature and pressure; E, performing air pre-pressing on the electroconductive polypropylene foamed beads obtained in the step D to enable high-pressure air to be stored inside the beads, and performing secondary foaming to obtain the high-multiplying-power electroconductive polypropylene foamed beads.