A leading supplier of nickel-chromium alloy sheets and rolls was facing increasing customer complaints related to inconsistent surface quality after storage and transportation. Although the material met all production specifications when shipped, residual rolling oils, organic contaminants, and microscopic surface films gradually affected the surface condition over time. As a result, customers experienced reduced wettability, poor adhesion performance, and inconsistent processing results during coating, welding, printing, and bonding operations. The supplier needed a solution that would improve surface cleanliness and help maintain product quality throughout the supply chain, ultimately increasing the shelf life of the material.
To solve this challenge, Keylink implemented an advanced atmospheric plasma treatment system equipped with a newly designed rotating plasma torch. The innovative torch generates a highly uniform plasma flame with a diameter of 40 mm, ensuring complete and consistent treatment across the material surface. For applications requiring larger treatment widths, plasma torches are also available with cleaning widths of up to 100 mm.
The process was developed for nickel-chromium alloy sheets and rolls consisting of 75% Ni, 16% Cr, 4.5% Al, and 0.5% Ti with a thickness of 0.3 mm. A specially optimized gas mixture containing 5% H2 and 95% N 2 was selected to maximize contaminant removal while preserving the integrity of the alloy surface. The plasma process effectively removed organic residues and reduced surface contaminants that could accelerate surface aging during storage.
Using a single rotating plasma torch, treatment speeds ranging from 2 m/min up to 50 m/min were achieved depending on the selected process parameters and cleaning requirements. The non-contact treatment process eliminated the need for wet chemical cleaning methods while providing highly repeatable results. For customers requiring higher production throughput, additional plasma torches can be installed in a vertical arrangement above the material path. By integrating a second or third torch, processing speeds exceeding 100 m/min can be achieved while maintaining outstanding cleaning performance.
The effectiveness of the treatment was verified through contact angle measurements. Before plasma treatment, the nickel-chromium alloy exhibited a contact angle of ≥91.9°, indicating low surface energy and the presence of surface contamination. After treatment with the Keylink atmospheric plasma system, the contact angle decreased dramatically to ≤12.8°, demonstrating exceptional surface cleanliness and significantly improved wettability.
The improved surface condition provided substantial benefits for the raw material supplier and its customers. Cleaner surfaces remained more stable during storage, helping to preserve material quality over longer periods and increasing usable shelf life. Downstream manufacturers received material with more consistent surface characteristics, resulting in improved adhesion, higher process reliability, and reduced production rejects. The supplier was able to enhance product value, reduce quality-related claims, and strengthen customer confidence in the delivered material.
This project demonstrates how Keylink atmospheric plasma technology combines advanced hydrogen-nitrogen plasma chemistry, innovative rotating torch design, and scalable high-speed processing to create a highly effective solution for raw material suppliers. By removing surface contamination before shipment, manufacturers can extend shelf life, improve downstream process performance, and deliver a higher-value product to their customers.
