Slitting is a process used to cut a wide coil of metal into several narrower coils. The process is primarily used to cut thin materials lengthwise and features a machine fitted with circular blades.
The entire process can be summarised in several steps, but before getting into the process, it’s important to note that there are two modes of slitting:
Straight mode slitting
In the straight mode slitting, the recoiler pulls the material from the uncoiler through slitters. If the uncoiler and slitter are driven only to feed the material to the recoiler, this is called pull-through slitting.
In driven slitting, the slitter is also driven during the process. In this process, the motors are synchronised to maintain a constant speed as the material moves through the line.
Driven slitting allows slitting of thinner sheets and a better edge quality for all thicknesses.
Free loop mode slitting
The material forms a free loop between the slitter and the recoiler in this method of slitting. A tension device is placed in front of the recoiler to ensure the 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-like buckles, thickness variations and twists. This improves the quality of the slitted strips.
Stages of Metal Sheet Slitting
Storage station – This is where the processed raw material and the workpiece is stored. For slitting, this is usually a big, broad roll of metal sheet.
Transport trolley – A trolley is used to move the workpiece from the storage station into the uncoiler. The unwinder does, as the name suggests. It 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 on the type of slitting the material undergoes. The slitter is set to cut the material in several narrow sheets as per the requirements of the order.
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.
Sheet metal slitting requires the careful setup 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.
At thyssenkrupp Materials UK, we have the latest slitting equipment from GEORG. Therefore, we can guarantee exceptional, timely, and efficient results to our clients no matter the size of the project. The line provides a very gentle treatment of highly sensitive surfaces such as surfaces for vehicle parts, coated strips or for example annealed stainless steel by means of braking processes adapted to the material surface.