Process & Facilities
Push Pull Pickling Line (PPPC)
|Thickness||1.20 – 6.50 mm|
|Width||600 – 1,650 mm|
|Inner Diameter||760 / 610 mm|
Before processing through pickling and oiling line, hot-rolled coil is unwraped, its surfaces are improved until smooth, and its head end is then sheared off.
For processing through tension section, the stitcher welds the steel strip of one coil to the coil following it. The strip’s edge is sheared in a concave pattern. Coiled steel of over 4 mm in thickness cannot be stitched or notched, and thus must be processed one coil at a time.
Steel strip with a thickness of 1.20- 4.00 mm must be smoothed out with a tension leveler before pickling. Steel strip with a thickness of 4 mm or more is conveyed directly into the pickling process.
Smooth steel strip is covered with a film of oxides. This deposit of rust is removed by means of hydrochloric acid in four different tanks, each with its own specific strength. The first tank has the weakest solution, and the last is the most powerful. In each tank is a squeegee roll, which prevents the acid from following along with the steel strip as it moves through. Used acid is treated and recycled in an acid regeneration plant. The fumes from the acid, meanwhile, are absorbed by water in a scrubber. The air emerging from this process is, therefore, free of acid vapour.
The side trimmer ensures that the steel strip is of the exact width desired by the customer. The upper and lower sides of the strip are then inspected for quality.
Having been rinsed, trimmed, and inspected, the steel strip is then oiled to guard against corrosion. A film of oil with a negative charge is sprayed over the steel, which has a positive charge. This electrostatic method ensures firm adhesion of the oil and a complete, consistent coating of the steel’s surface.
The steel strip is finally cut, wound into a coil, fitted with a strap, weighed, and given an attractive wrapping before delivery to the customer.
|Inner Diameter||508 / 610 mm.|
|Outer Diameter||915 – 2,150 mm.|