This invention relates to the field of polypropylene polymer materials, specifically to an extrusion-grade filled, reinforced, halogen-free flame-retardant polypropylene and its preparation method. The preparation method involves feeding raw material components into a twin-screw extruder via the feeding section, followed by blending, melting, and extrusion to produce the polypropylene material. Raw material components include polypropylene resin, phosphorus-nitrogen flame retardants, glass fibers, glass microspheres, and other additives. The twin-screw extruder sequentially comprises, along the material conveying direction: a feeding section, a melting and plasticizing section, a mixing section, a de-ash section, and an extrusion section. The feeding section's screw elements include at least two forward-rotating conventional conveying screw blocks and at least one forward-rotating large-lead deep-groove screw block. The forward-rotating deep-groove screw blocks with large pitch are positioned between the forward-rotating conventional conveying screw blocks. The forward-rotating conventional conveying screw block immediately following the deep-groove screw block has a double-head configuration. The pitch-to-diameter ratio of the deep-groove screw blocks is (1.5–2):1.
Country Code: CN
Application Number: CN202111257802.7
