Customized Roll Forming Machines for Cable Tray and Trunking Systems

In every modern commercial building, industrial facility, and infrastructure project, a hidden network of cable trays and trunking systems carries the electrical and data cables that power our world. These metal support structures—whether ladder, perforated, or wire mesh type—are formed from coiled steel on customized roll forming machines engineered for the specific sidewall profiles, return flanges, and safety edges required. This article examines how bespoke roll forming technology meets the demands of the cable management industry, producing strong, safe, and compliant cable trays at high throughput.

Cable trays come in numerous profiles: ladder-type trays with spaced rungs, ventilated trays with slot patterns, and solid-bottom trays. The side rails, typically a C-channel or a boxed flange, are the primary profile produced on a roll forming machine. These side rails often feature a return bend that creates a smooth, rounded top edge to protect cables from damage during pulling and to eliminate sharp edges for installer safety. The ability to consistently form this safety return lip is a hallmark of a well-designed roll forming line.

Material choice varies with environment. Galvanized steel to BS EN ISO 1461 is standard for indoor use, while hot-dip galvanized or stainless steel (304 or 316) is specified for outdoor, coastal, and chemically aggressive environments. Customized roll forming machines designed for stainless steel cable trays require special corrosion-resistant roll tooling, higher forming torque, and a stiffer machine structure due to stainless steel’s higher work hardening rate and strength. Roller materials may be switched to high-chromium, hardened D2 steel with nitriding treatment to resist the adhesive wear that stainless can cause.

A defining feature of a cable tray roll forming line is its ability to punch the rung holes or ventilation slots inline. The perforation pattern—often a series of slots for ladder rung insertion—is punched by a hydraulic or servo-press synchronized with the forming speed. The positional accuracy of these slots is critical for automated rung welding in a subsequent station. Some fully integrated lines couple the roll former directly to a rung welding machine: formed and punched side rails exit the roll former and enter a welding cell where rungs are automatically placed and resistance-welded to both rails simultaneously. This one-piece flow from coil to finished tray section eliminates handling and intermediate inventory.

The electrical industry requires cable trays in a wide range of widths—from 50 mm to 600 mm or more. A customized roll forming machine for this sector is often designed with an adjustable width capability. Instead of a fixed forming path, the roll stands can be moved laterally on precision rails via servo drives, allowing the same line to produce a 100 mm tray side rail and a 400 mm tray side rail without changing any tooling. The material width of the incoming strip changes accordingly, and the uncoiler and straightener are specified to handle the corresponding range. This flexibility is a game-changer for cable tray manufacturers who need to produce small batches of many sizes to order.

The finished tray sections are cut to length using a flying saw or hydraulic shear, usually in standard lengths of 3 meters or 2.44 meters. The cut ends must be clean and square to allow connector plates to bolt sections together in the field. A customized line includes a precision length measuring system, often a measuring wheel encoder, that triggers the cut accurately. The cut sections are then automatically stacked on a pallet by a robotic arm, completing the manufacturing cycle.

Customized roll forming machines are the engine behind the global cable management industry. They expertly transform steel coil into the precisely dimensioned, safely rounded, and accurately perforated cable tray side rails that support the arteries of the built environment. By integrating punching, welding, and flexible width adjustment, these machines deliver the productivity and adaptability needed to serve an ever-evolving electrical infrastructure market.