Traditional flattening methods are no longer competitive in the sheet metal industry. No wonder: flattening sheet metal with a hammer and flame, plate bending machine or press brake, does not reduce the material’s internal stresses. Material stress, however, has a pivotal impact on the effectiveness of downstream processes. When sheet metal parts are cut using a punch press or laser, the result is often bowed or warped parts, which can in turn negatively impact the entire process chain further down the line. What happens when inaccurate measurements or inconsistent bend angles render a part unusable? Time-consuming reworking, or even scrap, can lead to process delays and ultimately higher costs.
The high degree of automation in the sheet metal fabrication industry requires precision in the leveling process. Today, nearly every sheet metal fabricator can profit from an extremely precise and efficient roller leveler.
The roller lever works based on the following principle: The set of rollers is arranged in such a way that the sheet metal must pass through a series of consecutive alternating bending processes. The bending process is more substantial at the beginning than at end, resembling a decaying sine wave. The result is a straight, flat and largely stress-free part that prevents any unpleasant surprises that could otherwise arise in further processing. The number of rollers required depends on the strength of the material. A rule of thumb is that the more alternating bending processes the roller leveler has and the smaller the diameter of each roller, the less stress in the material and the better the results. When choosing a roller leveler, you should be sure that the rollers are adequately supported to minimize deflection. In addition, the machine should have features to prevent operator misuse and be easy to clean and maintain, preventing unnecessary production delays and increasing the life of the machine.
Nearly all metals, including steel, galvanized steel, aluminum and copper, can be straightened or leveled using a roller leveler. If you do not know the properties of your material, run leveling tests to see whether your material is suitable for a roller leveler. In principle, any bendable metal can be leveled. This is also true for hard and extremely high-tensile sheets. However, this requires rollers that are small enough in diameter to be able to sufficiently bend the material.
The sheet metal industry demands high quality. Defective products hinder automated processes, increasing costs of the finished product and thus lowering the supplier’s competitiveness. Using roller levelers reduces rework and scrap. Laser job shops, for instance, rely on roller leveling when their sheet metal has become unflat after laser cutting or punching and unsuitable for reliable further processing. But roller leveling allows these shops to weld the parts together in a faster and more precise fashion, reducing time-consuming rework processes.
A sample calculation shows that by using a roller leveler, you can produce more parts with consistently higher quality. The increase in efficiency reduces costs as shown by this example of a large construction machinery manufacturer: when using conventional flattening methods, such as a press brake, an operator needs 20 minutes to flatten each part on average. Flattening with a hammer and flame can take over an hour, even for the most skilled worker. When using a roller leveler, on the other hand, the same worker can process most parts in less than a minute. Overall, the use of a roller leveler reduces the entire work time for 60,000 parts to nearly 1,000 hours per year, approximately a tenth of the time it takes using conventional flattening methods. Reduced personnel costs and the significantly higher productivity, especially in terms of improvements in subsequent processing, can bring your company potential savings of several hundred thousand dollars per year.
Today, differentiating yourself with consistent high quality in a tough market is of utmost priority. Sheet metal fabricators must therefore explore new options in leveling techniques. The use of roller levelers is increasingly becoming the industry standard. Along with lower manufacturing costs, roller levelers save time and resources, freeing capacity for acquiring new customers and more work orders.