To avoid coating damage during the processing of stainless steel color plates, bending requires a comprehensive approach encompassing equipment optimization, process control, operational procedures, and post-processing. The core logic lies in reducing friction between the material and the die, controlling stress concentration, and mitigating the risk of mechanical damage through protective measures.
Die design is fundamental to preventing coating damage. The right-angled edges of traditional bending dies are prone to scratching the coating when the material slides. Therefore, a rounded corner design is necessary, and polishing should be used to control the die surface roughness to an extremely low level, reducing the coefficient of friction. Simultaneously, the slotting angle of the lower die's V-shaped opening needs to be adjusted according to the material thickness to avoid excessive material compression due to an excessively small angle. Furthermore, applying a wear-resistant coating or a polymer protective film to the die surface can further isolate direct contact between the metal and the coating, reducing the risk of scratches.
Precise control of process parameters is crucial. Excessive bending speed generates impact force, causing coating peeling, while excessively slow speeds may exacerbate friction due to prolonged material contact with the die. Therefore, a progressive stamping rate must be set according to the material characteristics to ensure uniform stress distribution when the sheet metal contacts the die. Pressure control is equally important; excessive pressure can crush the coating, while insufficient pressure may cause material springback, resulting in secondary damage. Dynamically adjusting the pressure ratio allows the sheet metal to maintain a stable deformation state during bending.
Standardized operating procedures are crucial for minimizing human error. Workpiece positioning requires dual verification using an optical alignment system and locating pins to prevent misalignment and friction between the material and the die due to offset. Before bending, the surface of the stainless steel color plate must be cleaned to remove dust, grease, and other impurities to prevent them from embedding in the bending area. For complex bends, a step-by-step approach can be adopted, first performing a small-angle pre-bend and then gradually adjusting to the target angle to disperse stress concentration. Furthermore, operators must wear appropriate protective equipment to avoid scratching the sheet metal due to clothing, jewelry, etc., coming into contact with the equipment.
The application of lubrication and isolation technologies can significantly reduce frictional damage. Applying a special lubricant to the contact surface between the die and the material forms a lubricating film, reducing direct friction. For high-precision machining, water-based lubricants can be used, as they have low volatility, are easy to clean, and leave no residue that could affect coating adhesion. In continuous processing scenarios, adding a flexible conveyor can prevent collisions during sheet material handling. Simultaneously, an automatic lubrication system regularly replenishes lubricant to ensure effective lubrication throughout the processing.
Post-processing is the last line of defense for repairing and strengthening the coating. After bending, the edges need to be sanded to remove burrs and micro-cracks, preventing them from expanding into coating peeling. For minor scratches, a localized spray repair technique can be used, covering the area with a repair paint of the same color as the original coating. Furthermore, spraying a transparent protective coating onto the bent area enhances its wear resistance and corrosion resistance, extending its service life.
Quality inspection and feedback mechanisms are the basis for continuous improvement. Using a laser profilometer to perform 3D morphological scanning of the bent sheet material can identify minute scratches and deformation defects. Establishing a defect database and correlating damage types with processing equipment, operators, and process parameters allows for tracing the root cause of problems. For example, if a batch of sheets frequently experiences edge coating peeling, the wear of the mold or the frequency of lubricant replenishment can be checked, and process parameters can be adjusted promptly.
Avoiding coating damage during the bending process of stainless steel color plates requires attention to detail throughout the entire manufacturing process. Systematic measures such as mold optimization, parameter control, standardized operation, lubrication and isolation, enhanced post-processing, and quality feedback can significantly reduce the risk of coating damage and improve product appearance quality and durability. This process relies not only on advancements in equipment and technology but also on meticulous attention to detail by operators to achieve a consistent output of high-quality processing.
