▎ 摘　　要

NOVELTY - Manufacturing high-span bridge beam draining pipe comprises (i) performing preliminary preparation and mixing by mixing high-density polyethylene resin, propylene copolymer, 2-4 pts. wt. acyl chloride grafted graphene and modifier, (ii) performing secondary addition and mixing by adding carbon black masterbatch, nano-calcium carbonate, light stabilizer, magnesium hydroxide, antimony trioxide, antioxidant and aging-resistant agent, and mixing and processing to prepare a forming material, (iii) placing the above forming material into an extruder for extruding and forming to obtain pipe, (iv) cooling and cleaning the extruded pipe through a pipe cooling and cleaning device, and (v) cutting and packaging by spraying and cutting the pipes after cooling and cleaning, checking and packing the cut pipes to obtain finished products. USE - The method is useful for manufacturing high-span bridge beam draining pipe used in traffic industry, buried or surface water supplying pipe, galvanized steel pipe, cast iron pipe, cement pipe and high-density polyethylene pipe. ADVANTAGE - The method: improves ability of pipe in impact resistance and environmental cracking resistance; increases the flexibility of the pipe; and solves the problems in the above-mentioned background technology that high-density will lead to insufficient stretchability of the pipe.