The world of sheet metal spans hundreds of industries and millions of parts. Each part has its own set of required features necessary for its proper function. The beauty of sheet metal lies in its ductility. Every sheet is a blank slate ready for unique contours, forms, beads, taps, markings, cuts and bends.
It is up to manufacturers to produce these components with the goals of speed, efficiency and quality. They must facilitate the process from material handling to final shipment. While there are countless methods that can be utilized to produce a part, the speed and flexibility of punch-laser combination machines offers a clear advantage for complicated part production.
The foremost step in sheet metal production is the loading of raw material. Loading standalone machines by hand requires one employee at a minimum and may require two or more for larger, heavier sheets.
Modern combination machines feature automated loading systems that can pull full 5-ft.-by-12-ft. sheets from storage carts and place them onto machines for processing. Sheets can be as thin as 0.040 in. and as thick as 5/16 in. Flexible automation options offer compact solutions as well as full multi-machine integration setups. Reliable performance can be ensured by sheet-peeling suction plates and thickness readers, which verify proper sheet picking. A variety of suction cup options enable the handling of textured sheets such as diamond plates or textured decorative panels.
Clamp sensors can ensure safe and secure material control for the high acceleration movements that take place during a program. All materials necessary for a production plan can be loaded and stored ahead of time from a loading station. In an optimized system, raw sheet loading can occur parallel to production, resulting in continuous operation and optimal machine utilization.
Ready, action
Once the sheet is loaded, the real action can start. Combining multiple operations on one machine reduces processing time, eliminates material handling between machines and ensures feature position and accuracy. Forming, stamping, embossing and part identification can be processed using standard and custom tooling. Roller tooling allows flexibility when forming beads and offsets. A thin sheet can gain strength and rigidity through the addition of beads.
Deburring can also be handled on some combination machines, which eliminates downstream processing. Wheel deburring tools offer the highest speeds while ball deburring allows for tight contours to be processed. Some punch machines can lower the die during position movements to eliminate unwanted marks on the underside of the sheet.
Adding threads to a part can be a labor-intensive step in sheet metal manufacturing. It can involve cinch nuts, weld nuts or a specific tapping machine that is used downstream. Modern punch combination machines can form threads in a wide range of materials. In thinner sheets an extrusion tool is used to increase tapping area. This replaces cinch nuts and weld nuts while reducing costs.
Formed threads are stronger than cut threads, do not create chips or shavings, and can be formed in less than 3 sec. Perforated patterns can be handled quickly as high-end punch machines can perform 1,600 hits in 1 min. When cluster tools are factored in, processing time can be lower than expected. Even small bends can be created on punch machines.
A combination machine offers the capability for laser cutting on top of forms created by the punch. This ensures dimensional accuracy of the contour as material stretching has already occurred. If a job requires a specially shaped contour, the laser can be used to start production while a custom tool is ordered. Combining technologies opens a world of possibilities with some machines creating multi-layer hems and taps through three sheet thicknesses.
When all forming and perforation is complete, the parts are ready for the final cut. Outside edges can be removed via punch or laser on a combination machine. The laser is the obvious choice for intricate contours and optimal edge quality. Combination machines can achieve cut speeds exceeding 1,500 ipm. The latest lasers can mark and cut a variety of materials including highly reflective metals like brass and copper. Laser time can be reduced by pre-punching the start points of each laser cut. This eliminates pierce time and any spatter that may occur as a byproduct.
While the ability to create laser cuts in outer contours is standard on combination machines, simple contours with majority straight edges can be punched quickly and with a lower cost than laser processing. Machines with brush tables minimize scratching as the parts are processed.
Part shakeup
One of the most arduous aspects of sheet metal processing is part removal or the “shake and break” method often required for parts that have been tabbed in. Modern punch-laser combination machines have automation available that can remove parts of almost any size – from the size of a matchbook up to a full 5-ft.-by-12-ft. sheet. Optical scanners ensure proper removal, and the machine continues to the next part. Prohibitively small parts can be processed with a laser and ejected by a special punching tool. This ensures reliable removals without the need for push-out paths. Automation methods lead to higher part quality and the elimination of ergonomic risk.
In full-scale production, finished parts can be sorted, stacked and stored while material for the next job is staged. Scrap skeletons are removed automatically and stacked on a tipping pallet for easy handling. Machines with strong automation allow for a second of third shift of operation to run with minimal staff requirements and these added shifts allow for increased production without expansion. A fabricator can take on larger jobs and facilitate tighter deadlines with the aid of a well-automated machine.
As fabrication technology continues to evolve, it is worth evaluating parts with consideration of the latest methods in mind. Combination machinery may offer the solution. Unique tooling allows forming and tapping operations to be performed on a single machine. Laser cutting capability helps maintain the highest edge quality and contour flexibility. Automation creates capacity and improved material handling. Part sorting options handle the offloading of finished parts and the removal of skeletons. Inclusive technology offers benefits across the board and introduces solutions that often surpass traditional part processing methods.
