Tyre Cord Spacing
Precise control of steel cords is required as they pass through a metallic calender. This is to ensure all steel cords are present and they are spaced correctly in the rubberised sheet. Unless an inspection of steel cords occurs, either after calendering on samples cut from the rubberised sheet or online as steel cords enter the calender, defects can occur further downstream in the tyre building process.
Sigmavision offers both offline and online steel cord insepction solutions. The offline system is a laboratory based vision system with LED illumination that detects steel cords on a cut sample taken from the calendered sheet. Cord number, spacing and density are calculated and reported on a PC running a dedicated software application. The online solution is a series of bespoke sensors with LED illumination mounted at the entry side of the calender and positioned above steel cords. The field of view of a sensor can be tailored depending on the maximum sheet width. When a missing cord is detected or a cord spacing lies outside the preset tolerance an alarm is communicated to the calender PLC. Read more