▎ 摘　　要

NOVELTY - Method for preparing polymeric positive temperature coefficient over-current protection element, involves (a) mixing 0.5-5 wt.% graphene slurry with 50-60 wt.% high-density polyethylene, vacuum drying and grinding to obtain powder (A), (b) stirring 25-40 wt.% conductive filler, 5-15 wt.% inorganic filler and powder (A) at high-speed, uniformly mixing, performing vacuum extrusion on mixed raw materials using a twin-screw extruder with different temperature zones to obtain an extrusion material, where zone (I) is carried out at 174-179 degrees C, zone (II) is carried out at 172-177 degrees C, zone (III) is carried out at 173-178 degrees C, zone (IV) is carried out at 172-177 degrees C, zone (V) is carried out at 173-178 degrees C, zone (VI) is carried out at 172-177 degrees C, zone (VII) is carried out at 173-178 degrees C and zone (VIII) is carried out at 174-179 degrees C, and (c) crushing extrusion material, pouring to an open mill, pulling out to form a core material, and the core material into required size. USE - Method for preparing polymeric positive temperature coefficient over-current protection element. ADVANTAGE - The protection element has excellent dispersibility and high resistance, and avoids the agglomeration of molecules. DETAILED DESCRIPTION - Method for preparing polymeric positive temperature coefficient over-current protection element, involves (a) mixing 0.5-5 wt.% graphene slurry with 50-60 wt.% high-density polyethylene, vacuum drying and grinding to obtain powder (A), (b) stirring 25-40 wt.% conductive filler, 5-15 wt.% inorganic filler and powder (A) at high-speed, uniformly mixing, performing vacuum extrusion on mixed raw materials using a twin-screw extruder to obtain an extrusion material, where the extrusion temperature involves performing zone (I) at 174-179 degrees C, performing zone (II) at 172-177 degrees C, performing zone (III) at 173-178 degrees C, performing zone (IV) at 172-177 degrees C, performing zone (V) at 173-178 degrees C, performing zone (VI) at 172-177 degrees C, performing zone (VII) at 173-178 degrees C and performing zone (VIII) at 174-179 degrees C, and the first three temperature zones are preheating temperature zones, which are carried out for 55-65 minutes, and (c) crushing extrusion material, pouring to an open mill, pulling out to form a core material, cutting the core material into required size to obtain the product.