The packing of aluminium extrusions has always been one of the particularly labour-intensive operations in the extrusion plant. That this activity too can be designed in a rational way was demonstrated by H+H Herrmann +Hieber in the context of its modernisation projects in a number of extrusion plants.
If it can be assumed in unfavourable cases that the packing productivity amounts to around 250 kg per man-hour, then in a plant with two extrusion lines (3-shift operation) about 42 people have to be occupied with packing the sections. Cost factors in this way of working are the high proportions of transporting and auxiliary activities, and the time spent by the packing workers just waiting around.
To rationalise these sequences, there are from the outset two approaches: to reduce idle times and to speed up the actual packing activity. The first of these is achieved by mechanising the transport of the sections and packing materials, and the second by designing and mechanising the packing stations ergonomically.
An example of this is the packing system installed as part of comprehensive modernisation measures at Aluminium Laufen AG in Liesberg, Switzerland. There, two mirror-image packing stations are supplied by a three-track roller conveyor. The full racks are brought into the packing station, automatically destacked and, when empty, placed on the empty rack return line.
The packing activities themselves still have to be carried out manually. To enable this as quickly, effectively and ergonomically as possible, the packing stations are equipped with every necessary work aid . Thus, the packing materials (paper, cardboard, foil, etc.) can be taken from dispensers directly adjacent to the packing position. The process of strapping is automated. The finished packs are moved onto a clearing roller track, where they are semi-automatically weighed and sent to the dispatch area.