FOCUS ON COIL PROCESSING
The shear in action on the line .
Protecting sensitive surfaces
Another decisive factor in Fischer Stahl ’ s choice was the sensitive treatment needed for coated or pre-painted material surfaces , ensured by a special foiling system upstream and corresponding intermediate rollers in the levelling machines . A flying , high-precision slide shear also minimises the cutting tolerance .
From a coil store with three places , a coil lift truck feeds the decoiler with coils of up to 15t in weight which can be uncoiled either from above or below . If there is an intermediate paper layer in the coil , it can be removed cleanly by a corresponding rewinder . Coils can be rewound that only need to be partially processed . The coil lift truck will return these partial coils to the coil store , where they are automatically weighed .
“ This means that Fischer Stahl can also assemble small batch sizes and still always
The CTL line control panel .
know exactly which quantities are being returned to the coil warehouse ,” Heinrich explained .
A jig integrated into the infeed group also helps to ensure that the cut-to-length line can flexibly handle a wide range of materials . It eliminates coil curvature , especially of thick starting material , so that the line can process strips across the entire range of 0.5 to 5.0mm thicknesses .
To cover the material thickness range across the entire processing sequence , Fischer Stahl decided on a solution with two integrated highperformance levelling machines from Schnutz GmbH , which are arranged directly one behind the other .
The levelling rollers ( with 70mm and 45mm diameters , respectively ) are installed in a compact cassette which can be easily removed for maintenance purposes .
“ Different materials require various settings of the so-called tilt , which deforms the metal in the leveller ’ s infeed ,” explained Heinrich . “ That ’ s why both levellers have a special tilt adjustment system that is able to compensate for various pre-deformations .”
The adjustment is made along the precision-manufactured curved sections and is characterised by its special rigidity . This ensures that the upper and lower levelling rollers are precisely aligned over the entire infeed range . To eliminate edge and centre waves in a targeted manner , the levelling roller supports ( in both machines ) can also be individually adjusted in a vertical direction .
The trimming shear is placed behind the infeed group to increase the cutting quality of the cut-to-length line . The precise bearing of the cutter shafts means that a burr-free cut is possible whereby the cutting gap is adjusted by axially moving the upper cutter shaft . The edge scrap of the belt , which can be trimmed up to 30mm on both sides , is shredded by a special scrap cutter which can be adjusted for different material thicknesses .
To process coated and surface-sensitive coils , a foil insertion device is placed in front of the two levellers . With their help , the upper side of the belt can be foiled before levelling and therefore protected in the subsequent process . The levellers themselves also feature special intermediate rollers that support the integrity of the surfaces during the levelling process . Behind them is a flying carriage shear which does not require an additional loop pit .
ISMR December 2021 / January 2022 | sheetmetalplus . com | 47