Efficient storage and retrieval of sheet metal

Storage News

	Tower store streamlines material flow, 24/7
A KASTO UNILINE storage system being used by a steel distributor.

Sheet metal machining facilities and distributors are investing more and more in automated storage and retrieval to streamline stock control and material flow through the operation, 24/7. At the same time, a company is able to store a larger amount of stock in a given footprint, saving valuable floor space compared with conventional racking.

Aimed at this market is Kasto’s new UNILINE single- or double-sided system with 200 to 800 storage locations for single-deep storage of sheet. Smaller and larger sheet metal storage systems are available from the company’s UNITOWER and UNICOMPACT ranges respectively, the latter configurable with thousands of locations.

Standard UNILINE pallets have a usable load of 3 tonnes, although 5 tonnes or more is possible on request. All systems can accommodate small, medium and large (3m x 1.5 m) format sheet; even extra-large and special sizes can be specified. Additionally, material can be stored on EURO pallets.

The rigid gantry crane is designed as a double mast unit with the handling equipment moving up and down between the masts. Lift movement takes place via two robust roller chains. A pull-push system is employed to handle the pallets. Precision roller chains with follower pins move the pallet into and out of the storage locations on plastic glides. These are virtually maintenance-free owing to the large support area, resulting in low surface compression. Another advantage is the increase in available space; telescope forks moving in and out would not permit such dense packing of the pallets in the shelf.

The storage locations and gantry crane are equipped with sensors to monitor the load height. With this information, inventory control computer KASTOlvr searches for a location to store the loaded pallet so that as little space as possible remains unused on top of the load. To check the height of the load, a scale can be integrated into the pallets, or the stations can be equipped with weighing cells, which is preferred in distribution centres.

To be able to store as much material as possible in the available footprint, it often makes sense to combine different sheet metal sizes, eg large and medium, in one location. One of the push/pull units on the loading traverse carriage of the gantry crane can be electrically moved into two positions so that, depending on the type of cassette, the loading traverse is adjusted automatically to the correct size. Adjusting the push/pull unit is time-neutral, since it takes place while the crane moves to the destination.

A UNILINE unpacking table with manually movable pins to assist removal of a wooden pallet from underneath a sheet metal stack.

Various methods can be used for sheet handling, depending on the application. Longitudinal and lateral carts are the simplest possibility. A pin table allows stacked sheet metal to be positioned after a lift truck or crane has picked the material off a wooden pallet. To guarantee accurate positioning and to achieve safe, unmanned interaction with sheet metal processing machines, the receiving stations are equipped with positioning bolts.

For more complex applications, two levels can be arranged on top of each other with the help of upper and lower carts, thus saving space. There is also the possibility of buffer locations outside of the steel structure for the supply of sheet metal to the system. If needed, the sheet metal pallet can be turned by 90 degrees or 180 degrees to meet the requirements of different sheet metal machine tool manufacturers.

Due to the modular design of the entire system, it can be modified to suit changing production and capacity requirements at any time without spending a lot of money.

For distribution centres, KASTO has developed an automatic sheet metal picking unit that can satisfy multiple handling requirements. A vacuum handling system has three sets of suction cups for dirty or oiled surfaces, for sensitive stainless steel and aluminum sheets, and for protective interlay sheets.

The sheet separator adjusts automatically to each sheet size – small, medium or large. The vacuum handling system removes and separates the desired number of sheets, removes the interlays and shreds them if required, and positions the sheets at a predetermined location on a wooden pallet.

The final tasks are packing and wrapping. Due to the relatively high degree of automation, it is possible to process 15 to 20 picks per hour with a UNILINE, without damage and with fewer personnel. Figures for UNITOWER and UNICOMPACT systems, by comparison, are 25 to 30 and 30 to 40 picks per hour respectively.

Automated sheet metal storage systems like the UNILINE offer enormous advantages for the intra-company material flow, utilisation of space and manning levels, with paperless inventory and order processing, from production planning or inventory management to sheet metal processing equipment. The system offers increased productivity, efficiency and competitiveness, so that investment in a UNILINE automatic sheet metal storage system can be amortised quickly.