In the summer of 2016, Stora Enso announced their intention to invest in Imatra mills in order to increase capacity for their production of extrusion coated products, and further enhance their position as a leading global supplier of premium paperboards. As a part of this announcement, along with the new polyethylene (PE) coating plant, the decision to invest in a new Automated Roll Warehouse (ARW) was also mentioned. THE NEED FOR SIMPLIFIED INTERNAL LOGISTICS Before this investment decision had been made, Stora Enso Imatra mills had been utilising external warehousing to store their intermediate roll buffer as there were warehouse space limitations at the mill with the traditional clamp truck warehouse concept in use. This meant multiple clamp truck handling phases between the base paper production, PE coating processes and shipping. Such a decentralised process inventory was challenging to control, very labour intensive to manage, and impacted the quality. All PE coated rolls had to be fully wrapped twice – first, to protect them during the clamp truck maneuvering within the intermediate storing process, and secondly, the PE coating was applied before customer shipments. For the automated roll warehouse, the target was to integrate a big WORLD PULP&PAPER 57 By Kaj Fahllund, VP Paper and Converting, Pesmel Oy Automated roll warehouse case study: Stora Enso Imatra enough intermediate roll buffer in the mill area between the production, converting and shipping processes, whilst being able to cut the costs through simplifying and automating the internal logistics. After lengthy feasibility studies comparing different alternatives, the Pesmel TransRoll deep channel rack storage concept proved to be the most cost effective solution to meet this need. ALTERNATIVE CONCEPTS FOR AN AUTOMATED WAREHOUSE For the last few decades, the synonym for an automated warehouse in the paper industry has been the overhead crane concept, where the overhead cranes (instead of clamp trucks) stack rolls on the floor into vertically stacked piles by vacuum gripper (unwrapped rolls) or by mechanical gripper (wrapped rolls). Most known suppliers for this warehouse concept are crane manufacturers such as Konecranes and Demag. By eliminating clamp truck traffic from the warehouse, the storing density can be improved by 30-40% when driving aisles are not needed. The crane-stacked roll pile heights are normally limited to less than ten times the roll diameters in By eliminating clamp truck traffic from the warehouse, the storing density can be improved by 30-40% Figure 1. Stora Enso Imatra mill’s new automated roll warehouse, used both as an intermediate and shipping roll buffer, L 108 m x W 42 m x H 33 m, in erection phase, summer 2017. In the distance, the board production lines can be seen; to the right is the shipping warehouse; to the left, the new PE coating plant is under construction. AUTOMATED ROLL WAREHOUSES