Identifying the mistakes is crucial to preventing common plate roll bending problems. Whether you’re new to operators with plate rolling or want to do a quick check to make sure you’re not making any simple mistakes, you’ll find something useful in this article. Let’s get started.
Mistakes made by operators account for many plate rolling problems, and the solutions to these issues are generally only a few preventative measures. Rather than wait for equipment downtime to find out that you have been making mistakes, undergo proper training to ensure machines remain operable. While it’s pretty simple to learn, there are a few things you’ll want to know before you get started. Let’s take a look at six common mistakes operators make when plate roll bending so you can be sure to avoid them.
When the steel plate is fed, the two sides of the steel plate should be perpendicular to the separation line of the shaft and the roller. They should be checked and prohibited frequently to prevent direction deviation. In production, the shaft rollers of the three-roller plate bending machine should be adjusted so that the planes parallel to each other are connected to each other to prevent the generation of cones.
Mistake 1: Incorrect Minimum Roll Bending Radius
First, you don’t want a roll bending radius that’s too tight because this results in broken equipment and inaccuracies in your final product. Any forming project needs to start with the material properties, including the yield and tensile strength, the radius being formed, and the length of the part. The higher the tensile strength and the tighter the radius, the more pressure you need to form. More pressure usually means more deflection, which in turn will change your machine requirements.
Mistake 2: Machine not Lubricated and Cleaned
Dirt and grime can accumulate on your machinery and keep it from performing as it should. Fortunately, you can prevent unnecessary damage to your most important equipment. To avoid malfunctioning machinery, regularly clean and lubricate all machine parts, including ram gibs and other critical components.
Mistake 3: Uneven Rolling
During cold roll bending, the metal might show some cracks on the edges. This phenomenon occurs from secondary tensile stresses induced at the workpiece surfaces. These cracks result from factors such as uneven rolling.
A trimming operation can remove edge cracks. Also, stretch and roller leveling under tension might work against edge cracks. Using edge rolls might help in achieving uniform rolls without any cracks.
Mistake 4: Wrong Roll And Workpiece Surface Damage
Plate rolling machines can be ordered with polished, precision-ground rollers that are simple to clean and won’t collect mill scale as frequently as conventional rolls.
Of course, mar-free bending requires the right procedures and careful tool handling. Precision-ground rollers are hardened, but they still can be damaged, so operators need to be aware of what they are sending through the rollers—especially when rolling narrow pieces, where the machine concentrates all its pressure on a very small area.
Mistake 5: The Rolls are Not Crowned
Plate rolling machines are most rigid at their side frames and the least rigid in the middle. If a machine had no method of crowning, the workpiece would force the middle of the bending area to bow in the plate rolling process, resulting in deflection.
Plate rolling machines have crowning methods that account for machine deflection. When the machine deflects, the forming pressure it exerts isn’t constant from one end of the machine to the other. Crowning counteracts this effect. In plate bending machines, the crowning is in the rolls. A crowned roll has a diameter that’s slightly larger in the middle, and that subtle “bulge” counteracts the deflection.
Mistake 6: Unshoveled Welds, Leveled Steel Plates
Unshoveled welds and unleveled steel sheets are rolled directly on the machine, which will damage the rolls. When the sheet enters the bending rolls, it must be perpendicular to the center line of the roller.