The Polyurethane (PU) Foaming and Polyethylene (PE) Wrapping Production Line is an advanced industrial solution designed for manufacturing high-performance pre-insulated steel pipes. This system integrates precise PU foam injection technology with durable PE outer layer wrapping, ensuring superior thermal insulation and long-term corrosion protection.

Widely used in district heating, oil & gas transportation, and chemical pipeline systems, this production line delivers consistent quality, high efficiency, and reliable performance for modern pipeline manufacturing.

• Integrated Production Process - Combines polyurethane foaming and polyethylene wrapping in one continuous, automated system
• High-Precision PU Injection System - Ensures uniform foam density, excellent adhesion, and optimal insulation performance
• Advanced PE Wrapping Technology - Provides a strong, seamless outer protective layer with high resistance to moisture, impact, and environmental stress
• Automated Control System - PLC-based intelligent control for accurate parameter adjustment, stable operation, and reduced labor requirements
• Energy Efficient Design - Optimized system reduces material waste and energy consumption while maximizing output

Rigid polyurethane spraying polyethylene winding prefabricated directly buried insulation pipe consists of steel working pipe, spraying polyurethane rigid foam insulation layer and winding polyethylene outer protective pipe.

1. Steel pipe rust removal - Hydraulic lifter transports steel pipe to conveying line. Shot blasting removes rust and impurities to SA2.5 standard
2. Polyurethane spraying - Steel pipe moves at constant speed while spraying robot applies foaming materials evenly. Multiple sprays achieve required thickness and compressive strength
3. Polyethylene pipe winding - Extruder applies molten polyethylene sheet that wraps around the insulation layer to form protective coating
4. Spray cooling - Semi-finished pipe is cooled by online spraying device, completing the insulated steel pipe production
5. Tracking and cutting - Automated system tracks and cuts pipes with high-speed saw blades, ensuring production continuity and efficiency
6. Numbering and storage - Finished pipes are numbered and moved to warehouse

• Uniform density, thermal conductivity, and compressive strength indices ensure superior overall pipe performance
• Enhanced compressive strength due to perpendicular foaming direction relative to pipe axis
• Stronger adhesion between steel pipe surface and polyurethane foam layer
• Rougher foam surface improves bonding with HDPE protective layer
• Customizable insulation thickness (15-20mm) for significant cost savings
• Adjustable insulation and protective layer thickness without additional molds
• Improved circumferential elongation and tensile strength from winding process
• Fully automated production ensures consistent quality and higher production speed

Qingdao Huashida Machinery Co., LTD is a manufacturer of series of plastic pipe machines, municipal pipe machines, pipe insulation & anticorrosion machines, and pipe jointing & anticorrosion materials, with more than 20 years of production experience.

• HDPE jacket pipe for pre-insulated pipe Production Line (110-2000mm)
• Rigid pre-insulated pipe Production Line
• Flexible pre-insulated pipe (PERT) production line
• Steel pipe FBE/2LPE/3LPE anti-corrosion coating line
• Steel pipe derusting line
• PE pressure pipe/Water Gas supply pipe production line
• PP/PE plastic board/sheet/geomembrane production line
• NBR PVC Thermal insulation tube/plate production line
• Pipeline anti-corrosion materials and instruments

We have been working with more than 400 overseas customers and exporting our products to Kazakhstan, Uzbekistan, Iran, Turkey, Russia, Nigeria and other countries.