Efficient Production of Large-diameter PE Pipes over 2000mm: Equipment Selection And Bkwell Process Control Solution​

Producing high-quality, ultra-large-diameter (≥2000mm) PE pipes demands extreme precision in equipment, process control, and operational expertise. Bkwell, a leader in plastic extrusion technology, leverages its extensive experience in large-diameter pipe production lines to deliver proven solutions. This article details key equipment configurations and production processes based on Bkwell’s technical expertise.Foshan Bkwell Machinery Co., Ltd. was established in 2017. It is a sub-brand of Jwell Group and is located in Shunde District, Guangdong Province. 

Ⅰ. Equipment Selection: Bkwell’s High-Stability Solutions

1. Extruder System (Core Bkwell Advantage)

• High-Efficiency Single-Screw Design: UtilizesBkwell’s high-performance single-screw extruder with L/D ratio ≥40:1 (e.g., Ø120/38 model) and high-torque drive. This configuration ensures uniform melting and low-temperature melt extrusion under high-output conditions, minimizing thermal degradation—essential for stable production of Φ1200–Φ2800mm pipes.

• Precision Control System: Integrates international PLC with Bkwell’s high-accuracy temperature control modules, limiting temperature fluctuations to ±0.5°C. This guarantees melt stability and prevents wall-thickness variations caused by thermal inconsistency.

2. Die & Calibration System (Bkwell Proprietary Design)

• Spiral Mandrel Die: Bkwell’s large-pipe die features high-strength forged alloy steel + hard chrome plating, with optimized spiral geometry. Integrated electric zone heating, multi-section temperature control, and air/oil hybrid cooling stabilize melt flow and temperature uniformity.

• Precision Positioning & Vacuum Control: Bkwell production lines minimize the distance between calibration unit and die head (typically ≤5 cm) and precisely balance vacuum tank water pressure to eliminate surface ripples/grooves. The Bkwell Smart Vacuum Regulation System maintains optimal vacuum levels (-0.05 to -0.08 MPa).

• Melt Cooling Unit: Bkwell’s patented melt-cooling heat exchanger between extruder and die reduces melt temperature, counteracting HDPE sagging in large-diameter pipes—a critical technology for wall-thickness consistency.

Ⅱ. Pre-Production Preparation: Bkwell Rigorous Protocols

1. Raw Material Pretreatment (Quality Foundation)

• Material Selection: PE100+ grade HDPE is recommended.

• Masterbatch Drying: Use Bkwell drying/dehumidification systems to ensure moisture content ≤0.01%, preventing bubbles or degradation.

• Material Preheating: Bkwell’s preheating system adjusts temperatures based on material status (virgin, moisture-affected, or recycled) to enhance melt fluidity.

2. Equipment Preheating & Calibration

• Uniform Thermal Soak: Activate Bkwell heating systems to achieve thermal equilibrium in dies and barrels. Extended heat preservation is critical for large dies.

• Calibration Unit Alignment: Adjust Bkwell’s high-rigidity calibration table with feeler gauges (gap error ≤0.2 mm) to prevent eccentricity.

Ⅲ. Process Control: Bkwell Intelligent Management

1. Temperature & Pressure

• Zone-Specific Control: Bkwell PLC temperature systems fine-tune extruder zone temperatures for complete material plastification.

• Mandrel Temperature: Bkwell’s closed-loop thermal oil system maintains mandrel temperature ≤220°C to avoid inner wall roughness.

2. Cooling & Haul-Off (Synchronization Critical)

• Graded Cooling: Vacuum tank water temperature: 10–20°C; spray cooling tanks use staged cooling (sectional ΔT <10°C), with final stage ≤10°C. Follows Bkwell cooling protocols to prevent stress cracking.

• Smart Haul-Off Sync: Bkwell digital haul-off synchronizes with extruder (error ≤0.5%) via PLC, adapting to extrusion speeds and pipe dimensions.

Ⅳ. Quality Assurance & Troubleshooting: Bkwell Proactive Measures

1. Surface Defect Response

• Roughness: Clear nozzle blockages/balance water pressure in Bkwell calibration units.

• Grooves/Ripples: Clean die impurities; adjust Bkwell vacuum control to -0.05–-0.08 MPa; replace screen packs if needed.

2. Dimensional Accuracy

• Measure OD/wall thickness every 30 minutes (OD tolerance: ±0.5%; wall tolerance: ±5%).

• Correct deviations via Bkwell control systems (die gap/haul-off speed).

3. Wall-Thickness Non-Uniformity (Bkwell Solutions)

• Die Calibration: Ensure concentricity; tighten bolts clockwise then loosen once; mark adjustment points.

• Parameter Optimization: Maintain melt pressure at 15–25 MPa (Bkwell pressure monitoring); sync extrusion/haul-off speeds (error ≤0.5%); balance spray angles/pressure.

• Real-Time Monitoring: Sample pre-cooling tank; use 8-point drilling tests; deploy Bkwell laser gauges for automatic feedback.

4. Sagging (Dripping) Mitigation (Bkwell Core Tech)

• Temperature/Cooling: Apply Bkwell low-temp extrusion (10–15°C below traditional); boost vacuum to -0.08 MPa.

• Process Upgrades: Optimized spiral die design; reduce haul-off speed (<50% rated); extend cooling time.

5. Ovality Control (Bkwell Precision Methods)

• Gravity Compensation: Install Bkwell hydraulic correction rollers (every 2 meters); balance adsorption via vacuum calibration.

• Process Adjustments: Zone-heat mandrels (ΔT ±2°C); clean calibration sleeves/seals to prevent localized resistance