The sheet metal fabrication industry has long grappled with an efficiency divide between low-volume, high-mix part flows and high-volume stamping production. Andrea Dallan, CEO of Italy's Dallan S.p.A. and author of "The Efficiency Revolution," proposes an innovative solution—coil-fed laser cutting and stamping technologies that create seamless "coil-to-completed-part" workflows to dramatically boost productivity and value output.
"True efficiency means delivering more value (finished workpieces) in less time while reducing waste (scrap)," Dallan emphasizes. While metrics like "inches per minute" and "strokes per minute" remain important, he argues they must be evaluated within the context of the complete "dock-to-dock" workflow.
Traditional sheet metal processing typically involves cutting coils into sheets that enter inventory buffers before laser cutting or stamping. Even with in-house cutting capabilities, sheet inventory often proves unavoidable. Coil-fed laser cutting eliminates this inventory step entirely.
Laser blanking technology stands out as particularly transformative. Originally developed as an alternative to traditional blanking presses for automotive manufacturers, this high-speed, flexible solution enables high-volume producers to design optimized blanks for subsequent stamping operations. In advanced configurations, lasers cut blanks while simultaneously destroying the surrounding skeleton, with robots automatically unloading and stacking parts.
Another coil-fed approach emerged from the need to process extra-long components beyond traditional press or laser cutting capacities. Material utilization optimization serves as another key driver. By nesting parts to accommodate any coil length, manufacturers can minimize scrap. These nests may contain identical parts or even assemble kits for downstream production.
While static nesting for standard products represents a typical coil-fed application, many manufacturers face dimensional variability challenges even with standardized items like range hoods. Dallan explains how dynamic programming environments can generate unique part kits each cycle through CAD software, with machine software automatically creating optimal material-saving nests from DXF files.
Parametric programming takes automation further by enabling complete front-end process automation. Using door panel manufacturing as an example, Dallan describes how scripts can create "master programs" that automatically adjust based on incoming order data. "This allows machines to bypass traditional CAD/CAM programming," he explains. "The system reads job lists containing specific quantities and parameters, then auto-generates drawings and nesting patterns."
Advanced inline systems now sequentially combine stamping and laser cutting. Coils first pass through levelers before reaching stamping stations where material feed stops for geometric processing—such as creating hole clusters, extruded holes, louvers, and other common forms using combination tools.
After stamping, shears cut custom sheet lengths that proceed to laser stations. Camera systems locate workpieces by measuring previously stamped features and sheet edges—particularly critical when sheet edges form part edges. Following positioning, fiber laser heads cut remaining part contours while stamping modules simultaneously process subsequent components.
These hybrid systems employ conveyor-style tables with replaceable metal support bars instead of traditional belts. Material skeleton handling varies by part geometry and downstream needs—some operations retain microjoined parts in variable-length sheets for optimal nesting, while others destroy skeletons during cutting or use pick-and-place robots for automated part separation.
Recent innovations include dual-head fiber laser systems where independent gantries prevent processing bottlenecks. "This configuration delivers stamping-equivalent throughput with greater flexibility for certain applications," Dallan observes.
For thin materials (0.03-0.10 inches), suspended laser cutting eliminates support bars entirely. In this method, material feeds forward, stops, and gets tensioned between opposing clamps. Lasers cut internal features and most contours before a conveyor moves beneath to catch parts during final skeleton separation.
While modern laser cutters offer impressive speeds, overall throughput ultimately depends on operational bottlenecks. Traditional laser departments may achieve high uptime, but their output still requires downstream forming, welding, and assembly.
Excess laser capacity helps manufacturers respond to inevitable changes—whether equipment downtime or rush orders. However, significant time gets consumed by post-cutting handling like manual part separation, stacking, deburring, and transportation. Coil-fed processing's true efficiency emerges when these steps become unnecessary through integrated workflows encompassing leveling, stamping, laser cutting, marking, and subsequent forming operations.
While not universally applicable—particularly for lines frequently changing material grades or thicknesses—coil-fed cutting proves compelling for operations primarily using a few readily available coil materials. A decade ago, lean manufacturing demonstrations at Legrand showcased how coil-fed roll forming with pre-stamping could reduce total manufacturing time from days to minutes through continuous flow rather than complex automation.
Today's coil-fed lines integrate with various automation systems—from pick-and-place robots to AGVs transporting parts to bending or welding stations. Dallan stresses that the technology's effectiveness stems not just from laser cutting speeds or stamping rates (though these remain important), but from total workflow velocity. For suitable applications, coil-fed processing can significantly enhance overall process efficiency.