Bending machine fault solution

When a bending machine malfunctions, it can cause the printing plate to tilt slightly, leading to misregistration in both positive and negative prints. Our company once faced this issue but initially overlooked it, failing to identify the root cause of the curved plates. Instead, we applied a temporary fix by placing tape on the inner corner of the plate to correct the overprint error. While this solution temporarily resolved the misalignment, it created a new problem: the plate cylinder's position no longer matched the angle of the plate after installation. As a result, the plate could not adhere properly to the cylinder surface, causing uneven pressure during printing. After approximately 10,000 impressions, the plate began to crack, which led to ink smudges transferring onto the printed material. At that point, we had to stop the press and replace the plate before the cracks worsened, which could have caused more severe issues.

Issues like these are commonly seen in newspaper printing. In addition to plate tilting, there are cases where the bending angle is inaccurate. These problems are often more subtle and harder to detect than obvious misregistration. For instance, if the tip of the plate isn't bent at the correct angle, or if the folding angle is too sharp, or if the bend is shifted backward, it can cause the layout to appear larger than intended. This may prevent the plate from fitting tightly against the cylinder, increasing the risk of damage. Therefore, if you notice misregistration during the print run or if the plate doesn’t fit snugly against the roller after installation, it’s important to check whether the bending machine is functioning correctly and consider making necessary adjustments. (Editor: Wang Xuebin)

It's essential for printing professionals to understand the importance of proper plate bending and alignment. A small mistake in the bending process can lead to significant issues down the line, affecting both print quality and production efficiency. Regular maintenance and calibration of the bending machine are crucial to prevent such problems. Additionally, training operators to recognize early signs of misalignment can help avoid costly downtime and rework. Whether working with high-volume newspaper printing or smaller custom jobs, ensuring accurate plate setup is a fundamental step in achieving consistent and professional results.