The problem of over-galvanizing of the edges on the normal operation of the production line causes the products produced are all waste products when the curling is curled, and the losses are very large. Therefore, it must first be treated from the perspective of reducing the loss of waste products. However, reducing the production line speed will increase the over-galvanizing of the side parts, so you can first use the air knife air pressure to reduce the overall galvanizing method. By producing a part of the product with low galvanizing content, it will strive for a period of treatment, so that it will not cause a lot of waste products, and it can also deal with the problem calmly. Generally speaking, the over-galvanizing of the edge mostly occurs when the galvanizing amount is high and the air knife pressure is low, so adding the air knife pressure often produces a certain effect.
The next step is to distinguish between raw material problems, zinc pot temperature problems or air knife parameter problems. The method is to observe the edge of the galvanized coil. If the galvanization is caused by slag, it is at the edge. If the edge is rough, white, and the gloss is not strong, it is often caused by raw material problems. Look for the raw materials to verify, to see if there is a phenomenon of edge trimming, whether there are edge cracks and jagged edges, etc. Generally speaking, the method of adjusting the air knife and using the baffle caused by the over-galvanizing of the edges caused by the raw materials are difficult to work, and only the materials can be replaced.
If it is obvious from the edge of the steel strip that comes out of the air knife that it has begun to crystallize, and the zinc flower on the edge of the galvanized steel plate is particularly small after cooling, it may be caused by the low temperature of the zinc pot.
If the edge of the galvanized steel plate is relatively smooth and the thickness is 4-10mm away from the edge, it may be over-galvanized due to improper matching of the air knife parameters. At this time, adjust the air knife angle first, and accurately confirm the actual air knife. The angle, especially the domestic Kohler air knife, must be carefully adjusted to ensure that the front and rear angles are offset by 1°-2° from each other. At the same time, make the distance between the air knife and the steel belt as small as possible.
If the above methods are not able to eliminate the problem of transitional zinc at the edges, the gap of the air knife must be stopped to adjust the gap of the air knife at the edge to make the gap of the air knife larger and further improve the zinc scraping force at the edge.
