Using roll-to-roll imprinting in coating of steel coils for corrosion prevention

Abstract

Passivation effect of coating is one of the most effective technique to isolate metals from corrosive materials. This paper presents a novel roll-to-roll (R2R) imprinting process for the application of epoxy coatings on steel coils to enhance corrosion resistance. The proposed process of the R2R system also enhances hydrophobicity as it promotes the formation of micro/nano structures on the surface of the epoxy.We first fabricated silicon molds using UV photo and colloidal lithography and dry etching. The silicon mold was then used to cast a UV-transparent mold of polydimethylsiloxane (PDMS) for attachment to an imprinting roller in order to pattern the surface of a polymer coating on steel coils. Imprinting was performed using epoxy acrylate which was simultaneously cured using a UV laser (wavelength of 405 nm). The results showed that epoxy acrylate has excellent imprinting surface structures without deformation at rolling line speed ≤1.5 cm/s. Structurally-imprinted surfaces were shown to reduce wettability, as indicated by measurements of static contact angle: epoxy acrylate with micro cylinders (122°), epoxy acrylate with hierarchical micro/nano-scale structure (131°), and bare steel (52°). Electrochemical analysis revealed that the corrosion potential of samples with micro/nano hierarchical structures (−515.7 mV) was substantially lower than that of the bare steel (−913 mV).

Keywords

• Micro/nano fabrication
• Roll to roll imprinting
• Anti-corrosion
• Colloidal lithography