Electric Cable Manufacturing Process Using PVC Granules

The manufacturing of electric cables with PVC insulation or sheathing typically involves the following eight major steps:

1. Raw Material Preparation

PVC Granules Selection

Dst Pvc Granules For Electric Cables Coating

Factories choose specific PVC compounds depending on cable type:

  • PVC insulation granules (for conductor insulation)

  • PVC sheathing granules (for outer jacket protection)

  • Specialized PVC compounds (e.g., flame-retardant, low-smoke, high-flexibility, anti-cold)

Before use, PVC granules are normally:

  • dried (to remove moisture)

  • pre-mixed with stabilizers or color masterbatch (if needed)

2. Copper/Aluminum Wire Drawing

Large copper or aluminum rods are drawn through a series of dies to reduce the diameter.

Process:
Rod → Annealing machine → Multi-die drawing → Fine wire → Take-up reel

The goal is to produce smooth, uniform strands suitable for conductor stranding.

3. Conductor Stranding

Multiple drawn wires are twisted together to form a conductor with:

  • higher flexibility

  • better electrical performance

Types of stranding:

  • Tight-stranded

  • Sector-shaped

  • Concentric

  • Compacted (for power cables)

4. PVC Granules Extrusion for Insulation

This is the critical stage where PVC granules are melted and applied onto the conductor.

Extrusion Steps:

  1. PVC granules fed into the extruder hopper

  2. Heated in barrel (160–190°C depending on formulation)

  3. Melt passes through screw compression

  4. Melted PVC is extruded around conductor

  5. Cooled in water trough

  6. Spark tester checks insulation purity

Result:
A perfectly round PVC-insulated conductor.

5. Twisting / Cabling (If Multi-core Cable)

For multi-core cables (2, 3, 4, or more insulated wires), the insulated conductors are twisted together.

May include:

  • fillers

  • binding tape

  • separator layers

This ensures cable roundness and mechanical stability.

6. PVC Sheathing Extrusion (Outer Jacket)

A second extrusion process applies the outer PVC sheath.

PVC sheathing material must provide:

  • abrasion resistance

  • weather and UV resistance

  • flame retardancy

  • mechanical strength

Process is similar to insulation extrusion:
PVC granules → Extruder → Melt → Crosshead die → Cable sheathing → Cooling → Printing

7. Printing & Meter Marking

The finished cable is printed with:

  • cable type

  • size

  • voltage rating

  • length marking

  • manufacturing date / batch

Inkjet printers are used during line operation.

8. Winding, Packaging, and Quality Inspection

Final steps include:

  • winding onto coils or drums

  • visual inspection

  • electrical tests (resistance, dielectric strength, spark testing)

  • mechanical tests (tensile, elongation, ageing)

Once approved, cables are packaged and ready for shipment.