Cracks along the edges of a moving web can cause lengthy downtime on subsequent processes such as a coater, re-winder or re-reeler in a paper mill. An edge crack or fold-over can hang-up on a slitter knife causing a blow-up which results in time consuming, costly clean-ups. When the location of every edge crack in a jumbo roll of paper is known then corrective actions can be taken by downstream operators to prevent the blow-up. Knowing when cracks are occurring on the paper machine can also provide Machine Tenders with valuable information that will help them eliminate the source of the cracks. A RYECO Edge Crack Detection System will eliminate all downtime in a paper line caused by edge cracks.
A RYECO Edge Crack Detection System utilizes a patented crack detection technology that combines high-speed optics with air jets to detect even the smallest cracks that are not yet open. As a crack passes through the ECD’s sensors, a small amount of focused air creates a small opening for the angled high-speed optics to detect the crack. The same air jets close the crack as it leaves the sensor, resulting in no touching or modifying of the crack. The crack opening only has to be 1/16" (1.6 mm) to be detected by the sensor and must extend in from the edge at least 3/8" (9.5 mm).
The response time of the high speed sensor is 50 microseconds. The sensor can be adjusted so that only larger cracks or fold-overs are detected. When the sensor is coupled with the RYECO Defect Marking System, all cracks in a jumbo roll are indicated as a colored ring to the winder or re-reeler operators. Typically, both edges of a paper machine are monitored for edge cracks and one edge (the edge facing the winder operator) is marked with a unique color for front and back cracks.