▎ 摘　　要

NOVELTY - Environmentally friendly flame-retardant thermal insulation PPR pipe comprises antibacterial layer, main body layer, flame-retardant layer and waterproof layer, the flame-retardant layer is made of flame-retardant particles, and the flame-retardant particles are made 80-100 pts. wt. polyethylene particles, 2.8-5.3 pts. wt. graphene powder and 12-20 pts. wt. brucite grafted polyimide. USE - Used as environmentally friendly flame-retardant thermal insulation PPR pipe . ADVANTAGE - The PPR tube has better flame retardant property and antibacterial property. The method is simple. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing environment-friendly flame-retardant heat-insulating PPR tube comprising (1) preparing antibacterial layer by adding 80-95 pts. wt. random copolymer polypropylene, 7-10 pts. wt. nano silicon dioxide load nano-silver antibacterial agent, 2-3 pts. wt. color master batch and 1-3 pts. wt. antioxidant mixing uniformly, adding into the extruder, extruding and molding, cooling to room temperature to obtain the antibacterial layer pipe body, the temperature of the material cylinder of the extruder is 175-187 degrees C, the temperature of the extruder mold is 191-207 degrees C, the temperature of the opening mold is 200-213 degrees C, (2) preparing main layer by mixing the 90-110 pts. wt. random copolymer polypropylene, 7-13 pts. wt. diatomite and 1-3 pts. wt. antioxidant uniformly into the extruder, the antibacterial layer pipe body passes through the mold opening of the extruder, extruding and molding, cooling to room temperature to obtain the main body layer pipe body, where the traction speed of the antibacterial layer pipe body is 0.5 m/seconds, the temperature of the material cylinder of the extruder is 175-187 degrees C, the temperature of the extruder mold is 191-207 degrees C, the temperature of the opening mold is 200-213 degrees C, (3) preparing the flame retardant layer by adding the flame retardant particles into the extruder, the antibacterial layer pipe body passes through the mold opening of the extruder, extruding and moulding, cooling to room temperature to obtain the flame retardant layer pipe body, where the flame retardant layer pipe body traction speed is 0.3 m/s, the temperature of the material cylinder of the extruder is 125-135 degrees C, the temperature of the extruder mold is170-180 degrees C, the temperature of the opening mold is 190-200 degrees C, (4) preparing waterproof layer by adding the TPU particles into the extruder, passing the flame retardant layer pipe body through the grinding port of the extruder, extruding and molding, cooling to room temperature to obtain PPR pipe, the traction speed of the flame retardant layer pipe body is 0.7 m/s, the temperature of the cylinder of the extruder is 160-170 degrees C, the temperature of the extruder mold is 172-180 degrees C, the temperature of the opening mold is 185-190 degrees C.