Chen Yan Yang, General Manager of Liansheng Paper, emphasises: "As part of our planned growth strategy, we are investing in new production and storage technologies at our location in Longhai in Fujian province. In Demag Cranes, we have found a reliable partner that will support us with all of its expertise. Thanks to the automated storage solution, we are able to save some 40 per cent of the space required compared to the originally planned manually operated store. Besides the large number of Demag paper roll stores installed worldwide, we were impressed by the newly developed gripper technology."
Thomas H. Hagen, Member of the Management Board of Demag Cranes AG and COO: "The contract awarded by Liansheng Paper underlines once again our leading role in the automated paper roll store sector. In addition to cranes, which we have successfully supplied with vacuum systems worldwide, we are increasingly utilising mechanical gripper systems with which our customers can also safely and reliably store packed rolls of paper."
Innovative gripper technology for Liansheng Paper
The first stage of development of the automated paper roll store operated by Liansheng Paper consists of two parallel bays, measuring 189 and 139 metres in length. Five fully automated Process Cranes with spans of 35.5 metres and load capacities of four tonnes pick up the rolls of paper and stack them up to a height of 14 metres. The cranes are equipped with mechanical grippers that can also transport sets of rolls.
To pick up the rolls of paper, a Process Crane is positioned by the warehouse management computer exactly above the centre of the roll. The six arms of the mechanical gripper gently enclose the rolls of paper, which, in this store, measure between 800 and 2,600 millimetres in length and between 1,000 and 1,300 millimetres in diameter. The ability to lift a set of up to four rolls simultaneously, measuring 3,600 millimetres in length, will result in a significant increase in handling speeds. The compact design of the mechanical roll gripper also makes it possible to achieve a tight storage pattern and, therefore, optimum utilisation of the space available in the automatic store. With a theoretical 100-per cent fill rate of 70,000 tonnes with specified roll diameters, the store operated by Liansheng Paper will be one of the largest paper roll stores in the world.
High safety standards
The handling of rolls in sets and the required subsequent separating of the paper rolls can only be achieved with a gripper that is specially developed for this application. The gripper is designed in such a way that the rolls of paper are safely and reliably held, even if rolls with differing diameters are picked up. Additionally integrated safety circuits - such as the redundantly designed sensors installed in the gripper - provide for reliable handling of rolls in automated storage processes.