With an annual capacity of around 75,000 tonnes, Constellium in Singen operates one of the largest aluminium foil rolling plants in Europe. The company produces high-grade aluminium foils and strips in the thickness range from 4 to 250 µm, used as pre-material for packaging materials and technical applications. For the flexible automation of the coil transport operations between the separating machines, the annealing furnaces and the packing stations, H+H Herrmann + Hieber installed a complex system of distribution trolleys and transfer carriages.
Thin aluminium foil is double-rolled, then separated by winding (separation) machines into separate coils and thereafter usually fully annealed to soften it. During this, the rolling oil residues remaining on the foil surface are vaporised and the foil is made completely sterile.
In the rolling plant in Singen two separation machines are arranged next to one another. In these machines, with a view to the subsequent annealing process the separated foil is wound onto metallic spools to form coils. Six of these foil coils at a time are placed in an annealing frame to be carried away. The coils remain in their frames until they are delivered to the packing station. For transporting the frames H+H installed a rail-guided system of automatic conveyor and transfer devices, the central component of which is a distribution trolley.
The central distribution trolley moves between the two separating machines and the packing station on one side and the chamber-type annealing furnaces or their associated intermediate stores and cooling positions on the other side.
The link to the separator machines in provided in each case by a transfer carriage. This delivers the empty frames, which are loaded at the machines and then move back to the transfer position to the distribution trolley. The empty frames needed are brought in by the central distribution trolley.
For the subsequent annealing process the distribution trolley takes the frames to a transfer position to the so-termed “charging trolley”, a distribution trolley for the transport to and from the furnaces. This is loaded with two annealing frames one behind the other, and then moves to the chamber furnace next to be used. For the transfer, the upper part of the charging trolley moves into the furnace and deposits the two frames. At the end of the annealing process this takes place in the reverse sequence and the hot frames are stored intermediately at cooling positions.
As called for by the packing station, one cooled frame at a time is taken up by the central distribution trolley and moved to the transfer position to a further transfer carriage, which takes over the transport to the packing station.
The frames used are welded steel frames which take up the coils at the ends of their spool. The entire frame is placed on the distribution trolley or the charging trolley. For loading and unloading the coils, lifting tables are installed at both the separating machines and the packing station, by means of which the trolley and frames are lowered by about one metre so that the upper edge of the trolley is at floor level. In that position the coils can be placed into the frames or taken from them. Once clear, the lifting table automatically moves back to the drive-in position.
In all, five different trolleys collaborate in operation in the coil transport system of the foil rolling mill in Singen. Two so-termed feeder trolleys (transfer carriages) carry out the transport between the separation machines and the central distribution trolley stretch. On that stretch the central distribution trolley transports full frames to the transfer points at the furnaces or to the packing station, and takes empty frames back to the separation machines. A fourth transfer carriage links the central distribution trolley and the packing station. The fifth trolley is the charging trolley, which moves up to the chamber furnaces.