Correct surface treatment in stainless steel products can prevent many problems

If stainless steel materials are not treated correctly, many problems can occur. Packo Surface Treatment, part of Packo Inox and the Verder Group, is specialized in the treatment of stainless steel. The company from Diksmuide offers a wide range of finishes: electropolishing, micro-undulation, amorphizing, deblurring, micro-deburring, blasting, grinding and polishing, pickling and passivation. In recent years, the surface finisher has observed some remarkable evolutions in stainless steel machining, such as the switch from non-stick coatings to non-stick electrochemical surface transformations, and the move toward overhauling and upgrading existing systems.

Packo Surface Treatment started in 1974 with the electrolytic polishing of stainless steel parts for milking machines. After all, ammonia and chlorine were causing corrosion of the stainless steel in milking parlors after only a few weeks. Electrochemical polishing suddenly solved the problem of corrosion and that of cleanability. In the meantime, the company is active in the most diverse sectors, and the possible surface treatments have also been considerably expanded, including de-rouging, refurbishment, desulphurization, micro-undulation, non-fingerprint finishing, E-polidur hardening, pickling, blasting, coating... If a customer has a problem, in many cases Packo already knows a solution.

To anti-stick electrochemical surface treatments

In recent years, however, there have been some notable evolutions in stainless steel engineering. For example, in the food industry, non-stick coatings are giving way to non-stick electrochemical surface treatments, such as micro-undulation, amorphization and electropolishing. In each of these cases, the surface remains the stainless steel itself, so no coatings, which by definition dissolve from the stainless steel anyway and end up in the food. 

"At Packo, we have developed suitable solutions for a wide variety of applications. For example, for the bakery sector we have developed a micro-undulation procedure that offers excellent non-stick properties in dough applications. Today we are also looking at replacing coatings in baking trays with a metal-like finish. Furthermore, electropolishing and amorphizing have been preventing blockages in applications involving flour, flours and other powders for some time," says manager Marc Quaghebeur. "Electropolishing is also increasingly being chosen for installations in meat processing plants. This avoids sticking, guarantees easy cleaning and prevents biofilm and fouling, contamination and bacterial growth. In applications involving starch, such as potatoes, mashed potatoes and cereals, we work with amorphizing because of its anti-stick properties, and in filling installations for drinking water, amorphizing with decalcifying agents has become indispensable. Finally, in rubber and latex applications, micro-ondulation is just about the only anti-adhesive treatment to date that offers adequate results."

Reconditioning and upgrading of existing stainless steel equipment

A second remarkable trend is due to the reduced supply of spare parts and finished products. As a result, in the pharmaceutical and food industries, more and more used and second-hand equipment is being used, which means that the overhaul and upgrading of stainless steel equipment has become very important. 

"At Packo Surface Treatment, we have the knowledge and technologies to repair damage and wear on products. Every day we receive vessels, reactors, mixers, filters, pumps and dosing sluices. We replace couplings, grind and weld up scratches, repair wear and corrosion, passivate or electropolish. Thus, in a very short time and at a limited cost, the customer gets a part that is sometimes finically better than a new product," Quaghebeur points out. "In their first life, a lot of the devices used did not have a high-quality finish, but when they are overhauled, treatments such as electropolishing, amorphizing or micro-ondulation are almost always provided. The almost improbable advantages of these finishes in terms of cleanability, anti-sticking, bacteria resistance and corrosion protection are now so well known that they have become self-evident in many applications."