We’ve recently discussed various metal treatments including the most common form of pickling, that being acid pickling in hydrochloric or sulphuric acid. Another more eco-friendly way of removing surface oxides from rolled steel comes in the form of a patented process called eco pickling surface (EPS).
EPS comes with an excellent set of benefits and is well worth understanding.
The Benefits of Eco Pickling Surface
A major positive of EPS is the fact that there are no corrosive chemicals used during the process.
The spent hydrochloric acids, along with other chemicals traditionally used in metal pickling require careful handling and disposal which comes at a cost for the company and the environment.
Eco pickling, much like Smooth Clean Surface (SCS) makes use of a smart abrasive system to effectively remove mill scale and other impurities from rolled steel.
The EPS machine receives the rolled steel and pays off into an uncoiler which levels the steel, effectively breaking the up the hardened surface scale. This then feeds into the first of several slurry blasting cells which consist of impellers which blast the metal surface with a mixture of abrasive and a carrier liquid – most often water.
Cleaning and rust prevention agents can be added to this mixture as it passes over the unrolled steel, and this slurry mix can be filtered and used again throughout the process. At the end of the EPS line, the meta is dried and run through a final check for residual oxide before being rolled back up, ready for action.
This system offers the same end result as does acid pickling, with less downstream industrial processes necessary and better rust resistance. In many cases, the EPS process results in a more uniform appearance than acid pickling, along with a lustrous finish minus minor scratches, pits or roll marks.
Indeed, a lower energy process using no corrosive chemicals or hazardous pollutants may well be the way of the future.