Manufacturing tubular busbars

Tubular busbars are manufactured through a precision-driven process involving material selection, forming, punching, bending, surface treatment, and rigorous quality control to ensure high conductivity and mechanical reliability.

Material Selection

The process begins with selecting high-purity conductive materials. Copper busbars typically use Electrolytic Tough Pitch (ETP) copper (C11000) with ≥99.9% purity, while aluminum busbars use 6101-T6 or 6063-T6 alloys for lightweight applications . Material choice affects conductivity, mechanical strength, and thermal performance. Tubular busbars may also require oxygen-free copper (OFC) for premium applications where weldability and minimal hydrogen embrittlement are critical .

Forming the Tubular Shape

Unlike flat busbars, tubular busbars are formed into hollow cylindrical or rectangular tubes. This is achieved through extrusion or rolling processes, where the raw copper or aluminum is shaped into a tube with precise wall thickness and diameter. CNC-controlled extrusion ensures dimensional tolerances within ±0.1 mm, critical for assembly and electrical performance .

Cutting and Punching

After forming, the tubular busbars are cut to the required lengths using CNC cutting machines. Holes for bolted connections or mounting are created using automatic punching machines or CNC punching systems, which ensure exact positioning and clean edges. Punching force is calculated based on material thickness, perimeter, and shear strength to prevent deformation .

Bending and Shaping

Tubular busbars often require bends to fit switchgear or panel layouts. Hydraulic or CNC bending machines are used to achieve precise angles while maintaining structural integrity. The minimum bend radius is typically 1.5 times the wall thickness to avoid stress fractures or reduced current capacity . Proper bending ensures reliable electrical performance and ease of installation.

Surface Treatment

To enhance conductivity and prevent corrosion, tubular busbars may undergo tin or silver plating. Insulation coatings can also be applied for safety in compact installations. Surface treatment ensures long-term reliability and compliance with electrical standards .

Assembly and Quality Control

Tubular busbars are assembled using mechanical fastening, welding, or laminated structures depending on design requirements. Dimensional checks, electrical performance tests, and thermal simulations are conducted to verify compliance with standards such as IEC 61439, UL, and CE . ISO 9001-certified processes ensure consistent quality for both small-batch and mass production.

Summary

The manufacturing of tubular busbars integrates high-purity material selection, precise forming, cutting, punching, bending, surface treatment, and rigorous quality control. Each stage is critical to achieving high conductivity, mechanical strength, and long-term reliability in electrical distribution systems, switchgear, and industrial applications .