Marine Steel Wire Rope Extrusion Line

Marine Steel Wire Rope Extrusion Line

A marine steel wire rope extrusion production line is a highly specialized industrial equipment system. Its core process is the hot extrusion method, which tightly coats a pre-manufactured steel wire rope core with a layer of polymer plastic sheath (mainly polyethylene PE or polypropylene PP).
This extruded plastic sheath is called the "protective armor" of the steel wire rope. It solves the critical weakness of traditional bare steel wire ropes, which are prone to corrosion, wear, and have a short service life in extremely harsh marine environments. The plastic-coated or sheathed steel wire rope manufactured through this production line significantly enhances the safety and efficiency of ship mooring, towing, lifting, and other operations.

Main Characteristics of the Production Line:

Continuous Production: Integrates processes such as wire rope pay-off, preheating, extrusion, cooling, traction, and take-up into a continuous automated production line.
Efficient Coating: Molten plastic is extruded through a die under high pressure, tightly combining with the steel wire rope to form a uniform, dense, and thickness-controllable protective layer.
Strong Adhesion: Ensures excellent adhesion between the plastic sheath and the steel wire rope through process control (such as preheating the wire rope), preventing delamination during use.

Core Components of the Production Line

A complete marine steel wire rope extrusion production line typically consists of the following key parts:
Pay-off System
Function: Supports and steadily releases the coil of steel wire rope to be coated.
Composition: Large spools or turntables, usually equipped with braking devices and tension control systems to ensure a smooth pay-off process and prevent the wire rope from slackening or over-stretching.
Preheating System
Function: Heats the steel wire rope before it enters the extruder head.
Importance: Preheating removes moisture from the surface of the wire rope and increases its surface temperature. This helps the molten plastic bond better with the wire rope, reduces internal stress, and prevents the sheath from cracking or debonding later during cooling due to different shrinkage rates.
Plastic Extruder
Function: The "heart" of the entire production line, responsible for plasticizing, melting, and steadily extruding the plastic raw material (PE/PP pellets).
Composition:
Hopper: For feeding plastic pellets.
Barrel and Screw: Core components. The screw rotates within the barrel, melting, compressing, and homogenizing the plastic pellets through external heating and shear heat.
Heating and Cooling System: Precisely controls the temperature of each zone of the barrel.
Drive Motor: Provides power to the screw.
Extrusion Die
Function: A key component that determines the final size, shape, and coating quality of the plastic sheath.
Composition: Typically uses a "crosshead" die. The die has precisely designed internal flow channels to ensure the molten plastic coats the passing steel wire rope uniformly and with high concentricity.
Cooling System
Function: Rapidly sets and solidifies the high-temperature molten plastic coated on the steel wire rope.
Form: Usually one or multiple series-connected cooling water tanks. Controlled cooling rates (e.g., spray then immersion) can prevent internal stress or deformation of the sheath caused by rapid cooling.
Traction System
Function: Provides stable, continuous pulling force for the entire production line, pulling the steel wire rope forward at a constant speed.
Composition: Usually consists of one or multiple pairs of rubber tracks or wheels that grip the cooled plastic-coated steel wire rope, providing constant and adjustable linear speed. Its stability directly affects the uniformity of the sheath thickness.
Take-up System
Function: Winds the finished plastic-coated steel wire rope neatly and tightly onto a spool.
Composition: Large take-up machine, equipped with a traverser (to arrange the wire rope neatly) and a tension control system to ensure winding quality.
Electrical Control System
Function: The "brain" of the production line.
Composition: PLC (Programmable Logic Controller), HMI (Touch Screen), temperature controllers, frequency converters, etc. It integrally controls the start, stop, speed synchronization, and temperature of all equipment, enabling automated production and monitoring.

Marine Steel Wire Rope Extrusion Line Datasheet

Model	30	40	50	60	70	80	90
Screw Diameter (mm)	φ30	φ40	φ50	φ60	φ70	φ80	φ90
Screw L/D Ratio	25:1	25:1	26:1	26:1	26:1	26:1	26:1
Extrusion Amount (kg/hr)	25	40	70	100	140	200	250
Outlet Wire (mm)	0.2-1	0.4-3	0.8-5	1-8	2-15	3-25	5-35
Total Power (KW)	18	20	25	33	40	55	63
Traction Power (KW)	2.2	2.2	4	4	4	5.5	5.5
Production Speed (m/min (Max.))	600	600	600	500	500	300	300
Take-up Spool (mm)	φ200-400	φ300-500	φ400-630	φ400-630	φ500-630	φ800-1000	φ1000-1250

Marine Steel Wire Rope Extrusion Line Application

The marine plastic-coated steel wire rope manufactured by this production line is widely used in ships and marine engineering due to its excellent corrosion resistance and wear resistance:
Mooring Lines
Application: Used to secure ships to docks, buoys, or offshore platforms.
Advantage: The plastic sheath effectively resists seawater corrosion, UV aging, and friction from docks, far exceeding the lifespan of ordinary steel wire ropes, greatly reducing maintenance costs and the risk of cable breakage.
Tow Lines
Application: Used by tugs to tow barges, other vessels, or offshore structures.
Advantage: High strength, wear resistance, capable of withstanding huge pulling forces and frequent bending. The sheath protects the internal wires from seawater erosion, ensuring reliability during long towing operations.
Lifting Slings
Application: Used for shipboard cranes, port cranes for loading/unloading cargo, or lifting equipment on offshore platforms.
Advantage: The plastic coating protects the wire rope from corrosion and surface damage, and is less likely to damage the surface of the lifted cargo compared to bare wire ropes. Good flexibility, safer operation.
Anchor Lines/Cables
Application: Connects the ship's hull to the anchor.
Advantage: Long-term immersion in seawater requires extremely high corrosion resistance. The plastic coating provides long-lasting protection.
Special Applications in Marine Engineering
Application: Such as support cables for submarine cables/pipelines, mooring lines for marine scientific research equipment, fixing cables for fishing nets, etc.
Advantage: The sheath can be customized with different colors, thicknesses, and materials according to needs to adapt to specific marine environments and functional requirements.