Efficacy of Cathodically Electro-Cleaning Nickel Thin Film Nozzle Plate for Piezo Inkjet Printer Head

• Published in: Japanese Journal of Applied Physics 2004-05, Vol.43 (5R), p.2645
• Main Authors: Lee, Sungkyu, Jang, Kwang-Kyun, Ahn, Jae-Hwan, Chung, Hyungsik
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.43.2645

A hydrophilic nickel nozzle plate for a piezo inkjet printer head with a minimum 5° water contact angle was obtained by (1) primary cathodic electro-cleaning of the detached nickel nozzle plate by applying a cathodic current density of 109.64 A/m 2 for 60 s in a thoroughly preelectrolyzed 20 wt% NaOH solution maintained at 97°C, and (2) secondary (post-treatment) cleaning by 1 or 2 min scrubbing of the primary cleaned nickel nozzle plate using a wiper soaked with a newly formulated post-treatment cleaner with inhibitor and surfactant to remove surface oxides and corrosion product films. The successful achievement of the hydrophilic nickel nozzle plate surface is attributed to (1) thorough and careful preelectrolysis of the primary 20 wt% NaOH electrolyte cleaner solution to remove dissolved oxygen and plateable cations, preventing potential aqueous caustic corrosion of the nickel nozzle plate under the more severe corrosive environment at 97°C compared with that of 25°C, and (2) proper formulation of the post-treatment cleaner solution, particularly the selection of the nonionic block copolymer type surfactant which not only assisted in widespread penetration of the cleaner into the NiO scale but also further improved the corrosion prevention performance of the inhibitor. The effect of post-treatment cleaning was experimentally substantiated by measurement of the water contact angle on the post-treatment cleaned nickel nozzle plate surface.