• Mechelonic Engineers Private Limited

Lap joint seam welders for steel mills

Steel mills require welders to join the tail end of one coil to the head of another coil in the various process lines. It is tedious and time consuming to thread the head end of a coil through the several meters length of the typical processing lines. To minimize setup time and improve productivity and throughput of the process equipment, the coils have to be joined in as short time as possible. In continuous process lines, it becomes imperative to have a quick and reliable welder to join the coils. This reduces the capacity of the accumulator and hence line investment. Mechelonic Engineers have developed a line of welders for the steel mills tailored for the particular requirements of individual lines. Basically the lower end machines have only the welding with an overlap joint. The machines can be incorporated with various accessories such as coil centering, re squaring shear, weld identification punched hole, notcher or half moon cutter, etc. Besides, automation to facilitate operation in fully automatic lines can be incorporated. At the upper end of the line are mash seam welders. These machines are used when the joint required is with minimal thickness to facilitate passage through pinched rollers without damage and direct coiling. The lap joint welders have two weld wheels, which are run on the top of the strip, whereas one of them does the actual welding, the other is used as a return conductor. These type of machines normally require lower power rating and are most economical in use. They however produce joints, which are eliminated during coiling of the strip at the end of the process line. The mash seam welders are configured with one weld wheel on top and the other underneath. The sheets are positioned precisely (with an overlap of 1.5 times sheet thickness) and the weld achieved is with a marginally higher thickness. The precision required for this process makes these machines relatively more expensive, but have the advantage that the joint can often be left in the coil and may be eliminated, if required at the users end.