Emulsion is used in cold rolling mills to lubricate and cool, and can cause corrosion to the strip if not removed. Removing the emulsion is a top priority, since, at its worst, can lead to scrapping of the entire steel coil.
In many cases, rubber wringer rolls, or squeegies, are used to remove emulsion from the steel strip. This can often cause problems, since the wringer rolls continuously need to be replaced for optimal effectiveness. Wear and damage on the wringer rolls have a negative impact on the result, and are both costly and inefficient. This can lead to wet strips in the process, which causes problems and can lead to scrapping of the entire steel coil.
To minimize emulsion problems, the wringer rolls should be replaced or supplemented with compressed air blow off. This is done by installing a specially designed air knife, developed for the steel industry. The compressed air efficiently dries and cleans the emulsion off the steel strip and results in less scrapping.