The working principle of the PPR pipe production line is based on plastic extrusion molding technology. Its core is to continuously process PPR (random copolymer polypropylene) pellet raw materials into standard-compliant pipes through high-temperature melting, pressure extrusion, sizing cooling, and fixed-length cutting.
The specific process is as follows:First, PPR raw materials are fed into the main hopper of a single-screw extruder. Inside the barrel, the materials are evenly plasticized into a high-temperature molten state under electric heating and shear action of the screw.Next, the molten material is continuously pushed by the screw into the annular die (die head), forming a hollow tubular parison.
The parison then immediately enters the vacuum sizing tank, where it is rapidly cooled and sized to a precise outer diameter under negative pressure adsorption and spray cooling.The sized pipe is pulled out at a constant speed by the haul-off machine and fully cooled in a spray water tank, with its dimensions monitored in real time by a laser diameter gauge and encoder.Finally, the pipe reaching the set length is automatically cut by the cutter, stacked or packaged after inspection, completing the continuous automated production from pellets to finished products.
The key to the entire process lies in the precise coordinated control of extrusion temperature, screw speed, haul-off speed, and cooling effect, so as to ensure the dimensional accuracy, roundness, and internal quality of the pipe.