How PE Pipes Are Manufactured？

QX-900 Automatic Vacuum Loading System/QX-150 Hopper Dryer/QX-300 Automatic Vacuum Loading System/QX-50 Hopper Dryer

• Additives: Essential additives are blended with the base resin:

• Stabilizers: Protect against degradation from UV radiation (carbon black masterbatch) and oxidation during processing and service life.

• Pigments: Usually carbon black for UV protection, but other colors are used for identification (e.g., blue for potable water, yellow for gas).

• Processing Aids: Optimize melt flow during extrusion.

• Mixing & Drying: Resin and additives are precisely metered and homogenized in a mixer. The mixture is often dried to remove moisture, which can cause defects during melting.

SJ75-38 High-Speed Single Screw Extruder/SJ50-33 Single Screw Extruder/SJ25-25 Co-extruder for Color Stripe

• Feeding: Granules enter the extruder's feed hopper.

• Melting & Compression: Inside a long, heated barrel, a rotating screw conveys the granules forward. Heat from barrel heaters and friction generated by the screw plasticizes (melts) the PE into a viscous, homogeneous melt.

• Metering: The molten plastic is pushed under high pressure and controlled temperature through a series of screens (a breaker plate) to remove any contaminants or unmelted particles.

Three-layer High-speed PE Pipe Die

• Annular Flow: The die head shapes the melt into a continuous, thick-walled cylindrical tube (called the parison). The precise design of the die gap determines the pipe's outer diameter and initial wall thickness.

• Types:

• Mono-Extrusion: Uses a single extruder and die for standard pipes.

• Co-Extrusion: Uses two or more extruders feeding a single die head. This allows for layers, such as a coloured outer layer for UV protection and a pure inner layer for potable water contact, or incorporating a barrier layer (e.g., EVOH) for gas pipes to reduce permeability.

Pipe Die Manufacturing Process

Spiral Mandrel Manufacturing

Pipe Vacuum Calibration Tank (9m)/Pipe Spray Cooling Tank (8m)

• Vacuum Sizing Calibrator: The parison enters a closed, water-cooled vacuum sizing tank. Inside, a precisely machined calibrator sleeve defines the final outer diameter. Vacuum applied through tiny holes in the sleeve sucks the molten plastic outward against the cool walls of the calibrator, setting the exact OD.

• Cooling Tanks: The pipe then travels through a series of water spray or immersion cooling tanks. Gradual and controlled cooling is critical to prevent warping, residual stresses, or crystallization issues that could weaken the pipe. Water temperature and contact time are carefully managed.

Four-claw Crawler-type Servo-driven Haul-off Machine

• Haul-Off Unit: Caterpillar tracks or belts gently grip the cooled pipe and pull it away from the die head at a constant, controlled speed synchronized with the extruder output. This determines the production rate and ensures consistent wall thickness.

• Straightening (Optional): For larger diameter pipes or specific tolerances, straightening devices may be used to ensure the pipe runs true.

Pipe Orbital Chip-free Cutting Machine

• Cutting: The continuously produced pipe is cut to specified lengths (typically 6m, 12m, or coils for smaller diameters) using automatic saws or cutters.

• Handling: Cut lengths are carefully handled (often using vacuum lifters or belts to avoid surface damage) and transferred to storage or palletizing areas. Ends are usually protected.

Precision Engineering for Longevity

The production of PE pipe is a sophisticated blend of materials science, precision engineering, and meticulous process control. From the careful selection and blending of raw materials to the high-tech extrusion, sizing, cooling, and rigorous testing, every step is designed to create a product that delivers exceptional performance, longevity, and reliability for critical infrastructure projects worldwide. Understanding this process underscores why PE pipe, particularly HDPE, is a trusted solution for demanding applications, offering a sustainable and efficient means of transporting fluids for decades.