Commercially slit coils can suffer from as much as 35 per cent of their edges not being cut cleanly, whether due to bad practices, poor quality material or worn tooling.
The result is that edge presentation at the welding point will be poor, and welding heat has to be increased to melt more material. Excessive ‘squeeze pressure’ also has to be applied to avoid defects. These issues will increase material and energy costs, as well as creating an excessively large inside/outside welding flash that then has to be removed.
The Duratrim edge scarfing system is designed to remove these problems, and trims the strip edges at the required rate, ensuring clean and parallel faces meet at the welding station. Clamed benefits of this process include reduced welding energy; consistent homogeneous weld integrity; reduced strip width/costs; ability to weld more challenging materials; and less OD/ ID welding flash (bead). A consistent strip width leads to fewer rejects. The unit runs dry, without emulsion.
The ‘floating’ design of the scarfing assemblies allows the unit to follow the path of the steel strip while maintaining positive contact pressure on the scarfing inserts. The system uses four sets of special scarfing inserts, which remove material from the strip edges, top and bottom. The inserts are supported and kept in position by eight pneumatic cylinders, the pressure of which is adjustable, enabling different amounts of material to be removed. All sets of inserts are mounted on a floating mechanism, ensuring constant material removal even with movements in the strip.
STE also offers a comprehensive range of welding consumables, including ferrite cores, impeders, induction coils and OD/ID scarfing inserts.