Until now, no inspection was possible during process steps in which the distance between the surface and the sensor varies. For example, no reliable quality assurance could take place on the rewinder of steel and aluminum strips. Therefore, it was previously impossible to inspect the final product. The Constant Pass-line Distance (CPD) technology from ISRA Parsytec with a movable sensor changes this. By keeping the sensor distance to the inspected surface constant, it is now possible to inspect lines with limited space, which was not possible before. Even a quality inspection on the rewinder can be performed. As a result, the CPD innovation enables certainty about the final quality and also provides documentation of the results.
With the Constant Pass-line Distance Technology (CPD), ISRA Parsytec presents a product extension of the proven SURFACE MASTER system. While these systems are usually stationary, the sensor can be moved thanks to the CPD extension so that the sensor distance remains constant to the inspected surface automatically. This opens up new installation possibilities, especially in lines where space is limited - wherever the so-called pass-line, i.e. the distance between the metal strip and a fixed system, changes. If the distance between the metal surface and the camera varies, a stationary sensor can no longer be used for a reliable inspection. With the CPD extension, the available space on the rewinder, for example, now becomes an installation option. Since winding of the metal strip causes the diameter of the coil to increase layer by layer, inspection is only possible if the inspection system adapts to keeping the same distance. At the end of the production process, a quality inspection verifies the final product grade. Inspection at this point benefits from an environment that remains largely unaffected by influences such as dirt, dust, or water vapor, plus CPD monitors the correct winding process.
The CPD system extension is equipped with a distance measuring device that helps to regulate the distance to the strip surface fully automatically. This is particularly necessary when strip layers are rolled up on the coil. The inspection system is installed in front of or directly behind the rewinder and shifts accordingly with each new distance change. Now, the CPD extension allows systems to be installed at new locations in the process, often making optical inspection possible for the first time. Complete documentation is available for all production lines for quick quality assurance to the customers. Furthermore, CPD monitors the correct winding process, monitoring that metal strip coils are rolled up exactly centrically, detecting any "telescopic effect" that may occur. The online displays of the inspection results enable operators to draw direct conclusions about the process quality. The gained data then creates the basis for production optimization to sustainably reduce costs and increase the total yield of a production line. State-of-the-art camera and lighting technologies ensure razor-sharp defect images, combined with sophisticated software, provide for highly reliable detection and classification of all defects.