FOCUS ON COIL PROCESSING
the recoiler to ensure that coils are properly wound. This method is recommended for poorly shaped coils. Sometimes, a temper mill or a leveller can be added to the slitting line to correct defects in the incoming coil( such as buckles, thickness variations and twists). This improves the quality of the slit strips,” it added.
There are various stages in the metal slitting process, which are detailed below:
■ Storage station: This is where the processed raw material and the workpiece is stored. For slitting, this is usually a big, broad roll of sheet metal. set-up of the slitting machine to avoid inconsistencies that could be caused by leaving the blades with too little clearance, too much clearance or without proper vertical clearance,” said ThyssenKrupp Materials.
Coil coating
Coil coating is a reel-fed continuous process for painting metal which is then used to make a finished part. In one continuous reel-to-reel process, a metal coil of material is unwound, cleaned, primed and then coated with up to
Image: NLMK.
Coated coil.
two layers of paint on each side, before being thermally cured and then rewound.
The process allows for different colours and patterns to be applied to each side of the sheet. In addition, a strippable plastic film layer can be added for extra surface protection. Once coated, the coil is then further processed to give users the material in the dimensions and formats that they require.
Coated coil can be slit for narrow widths, cut to required lengths, bent, profiled or deepdrawn without damaging the organic coating. It can be processed into any number of shapes, depending upon the end use.
The coil coating process itself offers a range of economic and environmental benefits. It is a closed loop process, so the release of harmful elements is eradicated. All solvents / organic compounds are captured and treated before emission.
In conclusion
Coil processing benefits manufacturers by increasing production speed and efficiency, reducing material costs and waste, improving product quality and consistency, and enhancing workplace safety.
By automating handling and processing through systems that work with continuous coils, manufacturers can lower labour costs, achieve higher throughput, maintain tighter tolerances and adapt more easily to various needs, making the process suitable for highvolume, consistent production. n
■ Transport trolley: A trolley is used to move the workpiece from the storage station into the uncoiler. The unwinder unwinds the coil as it feeds the metal sheet into another machine for slitting.
■ Slitter: Once the material leaves the uncoiler, it is fed into the slitter. How this happens depends upon the type of slitting used. The slitter is set to cut the material in several narrow sheets, according to the order requirements.
■ Recoiler: The last stage of the process is the recoiler. It is the opposite of the uncoiler. The recoiler winds the different strips of materials neatly. In some cases, a tension device can be used to ensure the coils are neat and firm.
Image: Henkel.
Scrap winders are usually a component of a slitting line. A scrap winder operates at the same speed as a slitting head to wind edge-trimmed material from the slitting head into the unit. Once the scrap winder is full of material, the operator will strap the wound scrap and move it to an area in the plant where slitter scrap is collected.
“ Sheet metal slitting requires the careful
Image: Athader.
70 | ismr. net | ISMR October 2025