1. It uses the roller electrode to replace the cylindrical electrode of spot welding and as the welding work piece moves between the rolling plates, the seal welding will generate weld nuggets which will overlap with each other so as to achieve welding effect.

2. Generally, AC pulse current or amplitude modulation current will be adopted, but three (single)-phase rectification, medium frequency and high frequency DC are also available. In general, the welding thickness is within 3mm of single plate.

Seam welding machine is a method that uses a pair of roller electrodes instead of the cylindrical electrodes of spot welding, and the welded workpiece moves between the rollers to produce a sealed weld with a molten core overlapping each other to weld the workpiece together. The weld consists of a single weld joint, which is divided into roll spot welding or gas-tight seam welding according to the different core fusion overlap.

1. seam welding machine use the roller electrode to replace the cylindrical electrode of spot welding.

2. It will generate weld nuggets which will overlap with each other so as to achieve welding effect.

3. AC pulse current or amplitude modulation current will be adopted, but three (single)-phase rectification, medium frequency and high frequency      DC are also available.

4. According to different overlap of the melting cores, it could be divided into roll spot welding and air-tight seam welding.

5. There exist three stages in the forming process of welding spots: pressurization, heating fusing and cooling crystallization like spot welding.