HV & EHV Power Cable Extrusion Line

HV & EHV Power Cable Extrusion Line

HV & EHV cable extrusion production line is a special equipment used for manufacturing the core part of high-voltage and extra-high-voltage power cables (usually referring to voltage levels of 110kV and above). Its core process involves extruding and coating specific functional plastic or rubber layers onto the conductor (copper or aluminum) layer by layer, forming the insulation and shielding layers of the cable, thereby ensuring the cable can withstand extremely high electric field strength and operate safely and stably. This production line is a technology-intensive system with extremely high precision requirements, representing the highest level in the wire and cable manufacturing industry.

Core Components

A complete high-voltage cable extrusion production line typically consists of the following major systems:
Pay-off System
Function: To smoothly release the conductor (such as copper core) and maintain constant tension.
Features: Usually equipped with dual pay-off stands (one active, one standby) to enable continuous production without stopping. It includes a precision tension control system to prevent the conductor from being stretched or damaged.
Preheating System
Function: To heat the conductor before it enters the extruder head.
Purpose: To remove moisture from the conductor surface and bring the conductor temperature close to that of the molten plastic, reducing the temperature difference between the inner and outer layers, preventing inner layer cracking due to thermal stress, and improving the adhesion between the plastic and the conductor.
Extrusion System
This is the core part, typically adopting the "two ore more layers co-extrusion" mode, where two or more extruders work simultaneously to extrude different materials into a common head, forming two or more layers in one step.
Cooling System
Function: To gradually and slowly cool down the cable after cross-linking is completed.
Features: Segmented cooling is adopted, with water temperature precisely controlled from high to low. Rapid cooling can cause internal stress and microvoids in the insulation layer, affecting the cable's lifespan, so slow cooling is essential.
Pulling System
Function: To provide power for the entire production line, pulling the cable forward at a constant or synchronized speed.
Features: Dual pulling (e.g., belt-type puller + drum-type puller) or multi-stage pulling is used to provide strong pulling force and maintain extremely stable speed. Any speed fluctuation can cause uneven insulation layer thickness.
Take-up System
Function: To neatly wind the finished cable onto large cable reels.
Features: Take-up tension must be precisely controlled, and winding must be neat and tight. It is usually equipped with an online diameter measuring instrument and a spark tester (for medium and low-voltage sheaths) for online quality inspection.
Central Control System
Function: The "brain" of the production line. Integrated with PLC and industrial computers, it monitors, records, and performs closed-loop control of hundreds of parameters throughout the production process (such as temperature zones, extruder speed, pulling speed, pressure, nitrogen flow, cooling water temperature, etc.).

HV & EHV Power Cable Extrusion Line Datasheet

Model	200+120
Screw Diameter (mm)	φ200+φ120
Screw L/D Ratio	25:1
Extrusion Amount (kg/hr)	φ200: ≤1000 kg/h, φ120: ≤500 kg/h
Inlet Wire (mm)	55-160
Outlet Wire (mm)	70-180
Traction (N)	≤32000
Production Speed(Max., m/min)	30
Pay-off Spool (mm)	φ2000-φ4200
Take-up Spool (mm)	φ2000-φ4200

Core Components List

Ø200~Ø4200 Rail-mounted Motorized Pay-off Stand	2 sets
3200kg Auxiliary Caterpillar Puller	1 set
Asphalt Coating Unit	1 set
Ø200 Extruder	1 set
Ø120 Extruder	1 set
Dual-layer Extrusion Head and Cart	2 sets
Extrusion Head Vacuum Unit	1 set
Mobile Water Trough and Hot Water Tank	1 set
Stainless Steel Cooling Trough	1 set
Cable Air Wiping / Drying Unit	1 set
Length Counter / Meter Counter	1 set
3200kg Main Caterpillar Puller / Haul-off	1 set
Graphite Coating Unit	1 set
Ø200~Ø4200 Rail-mounted Motorized Take-up Stand	2 sets
Spark Tester	1 set
Electrical Synchronous Control System	1 set

HV & EHV Power Cable Extrusion Line Application

The HV & EHV cable extrusion production line is a complex system engineering that integrates mechanical, electrical, material, thermodynamic, and automatic control technologies. The core of its technology lies in the "two or more layers co extrusion". Through ultra clean environment and extremely precise control system, it ensures that the produced cable insulation layer has the characteristics of no impurities, no micropores, high uniformity, and perfect interface, thus meeting the safe operation requirements of the power grid for high reliability and long life. This production line is mainly used for the following occasions:
1. Used for manufacturing cross-linked polyethylene insulated (XLPE) power cables with voltage levels of 110kV, 220kV, 500kV and above.
2. The cable core used to manufacture submarine high-voltage cables.
3. Used to produce high-voltage special cables for special purposes.