Metsä Board’s Husum mill operates in the small village of Husum in Sweden. The mill is an integrated board and pulp mill and produces 730,000 tons of bleached market pulp every year, 400,000 tons of folding boxboard, and 250,000 tons of kraft liner.
Creative engineering required
Metsä Board had shut down two paper machines and replaced them with a new state-of-the-art paperboard machine from Valmet in 2015–2016. One paper machine was converted to produce linerboard. The mill has since been producing 500,000 tons of paperboard a year on two production lines. Fine paper sheet cutting operations were also stopped, and were replaced with a new extrusion coating line. These changes required a new intermediate roll storage (IRS) between the paperboard production lines and the extrusion coating line.
“Because the TransRoll™ system is scalable, it can be fitted into small, low spaces as well as large, high ones.”
The best location for the IRS was the old empty sheeting hall next to the new extruder line. However, this hall was limited by both its six-meter ceiling height and small footprint. The height limit meant that stacking rolls would not make efficient use of the vertical space, offering only limited storage. In addition, the floor area was not suitable for traditional clamp trucks or automatically guided vehicles (AGVs), because half the floor space would be needed for vehicle access routes.
A scalable solution
Pesmel proposed a solution based on the TransRoll™ automated storage concept after studying the storage hall and its dimensions. The solution is scalable, and can be fitted into small, low spaces as well as large, high ones. The TransRoll™ rack was scaled to fit the available height providing two levels of TransRoll™ channels for rolls with a maximum diameter of 1.8 meters. To make the most efficient use of the floor area, asymmetric channel lengths (24 m and 17 m) were selected to be served by a single stacker crane in the aisle between them. This layout optimized the use of vertical and horizontal space providing double the storage volume of an autonomous guided vehicle (AGV) solution. The whole system, including all features of handling and sorting, is controlled by Pesmel’s intelligent Warehouse Management System (WMS).
Despite its compact size, this tailored TransRoll™ automated storage concept successfully fitted 4,500 tons of paperboard into a space of 3,180 square meters, with just a six-meter ceiling height providing a handling capacity of 300 tons of paperboard an hour. Fire safety was also integrated into the system with sprinkler pipes on the racks on each level of the storage. The stacker crane that handles the rolls is an additional benefit of choosing the TransRoll™ solution. This significantly reduces the need for conveyors.
Tailored solutions with smart engineering:
- Scalability; TransRoll™ fitted into an only six-meter-high space
- Clever use of space; 4,500 tons of paperboard stored in 3,180 m2
- Handling capacity of 300 tons per hour