Treatment equipment and furnaces
Sirio Wire's new copper coating line: built for special nickel alloy wires
Sirio Wire has successfully introduced a new electrolytic copper coating line designed for special nickel alloy wires. The copper coating acts as a lubricant for subsequent cold heading operations, where coating quality and adhesion play a key role in ensuring process efficiency and product performance.
A complete in-line process from pay-off to take-up
The new installation has been engineered as a fully integrated in-line system, ensuring continuous processing, high repeatability, and consistent coating quality. A typical line configuration includes:
- pay-off and wire straightening device;
- electrolytic activation (or depassivation) section;
- rinsing and air wiping;
- nickel coating section;
- rinsing and air wiping;
- copper coating section;
- final hot rinsing and air wiping;
- take-up unit.
The process is capable of producing copper coatings up to 10 microns thick, with excellent adhesion to the wire substrate.
Nickel interlayer ensures strong copper adhesion
One of the most important technical features of the process is the electrolytic activation section, which removes the passivation film naturally present on stainless steels and special alloys. This preliminary treatment prepares the wire surface for the subsequent coating stages.
Copper deposited directly onto stainless steel typically presents poor adhesion. To overcome this challenge, the line incorporates an intermediate nickel coating stage. Nickel adheres perfectly both to the stainless steel substrate and to the copper layer applied afterwards, acting as an effective bonding layer between the two materials. This combination ensures the excellent final adhesion of the copper coating.
To guarantee thorough cleaning between each process stage, Sirio Wire employs its proprietary high-pressure water rinsing system, designed to achieve maximum rinsing efficiency. In addition, air drying devices positioned between the sections minimize liquid drag-out and help maintain process stability and coating quality.
Advantages of in-line coating technology
Compared with conventional batch coating systems, the in-line process offers several operational and environmental benefits, including:
- reduced heat losses;
- improved coating homogeneity;
- more environmentally friendly operation;
- lower manpower requirements.
For more information about this and other Sirio Wire solutions for metal wire surface treatment, please visit the company's online showroom on Expometals or contact Sirio Wire directly using the contact details available on its profile page.
