Narrow edge rolls of the type that are normally left over when corrugated base paper is cut are normally recycled. A newly developed system from Erhardt+Leimer called “Skiver Line” now offers paper manufacturers the chance to glue these edge rolls together to form full rolls with the required width.
The machine unwinds the two edge rolls that are to be joined together, keeping them parallel while it does this. It grinds a chamfer into the upper inner edge of one of the paper webs and into the lower inner edge of the other, before then gluing them precisely together to form a full-width web. Because a chamfered profile is created on the two edges of the webs before they are glued together, there is no increase in thickness at the joint. The system glues together edge rolls with a width of 500 to 1400 mm into webs with a maximum width of 2800 mm. Here, different widths of edge roll with different diameters can be combined. The process has no influence on the overall strength of the end product, e.g. the corrugated cardboard.
Only two people are required to operate the system. They need to place the edge rolls in the two unwinders, monitor the grinding and gluing process, and unload the finished rolls from the surface winder. The Skiver Line system is designed for 24-hour production with only minimal requirements for maintenance downtime.
Different options are available for the system. For example, on request the Skiver Line can be equipped with a slitter that trims the joined web on both sides to the required width. Further options include a web cleaning system, cameras for process monitoring, and the possibility to integrate a coating unit provided by the customer.
By converting excess edge rolls into standard, full-width paper rolls, the Skiver Line enables savings to be made in terms of recycling costs, and allows value to be created that will allow the system to pay for itself in around two years. The return on investment calculation is based on 3-shift operation running 5 days a week and 45 weeks in the year.