TECHNICAL FIELD
Present disclosure relates, in general, to the field of metal coating. Particularly, but not exclusively,
the present disclosure relates to a method of coating a metal substrate.
5
BACKGROUND OF DISCLOSURE
Electrodeposition or e-coating is generally utilized in various industries including but not limited
to automotive industry, aerospace industry and electronics industry. Electrodeposition is a process
10 for applying corrosion resistant coatings to metal surfaces via electrochemical deposition of a filmforming composition under an influence of an applied electric potential. Conventionally, the
electrodeposition involves several steps. The usual steps involved in applying e-coating to metal
parts within an industrial setting include cleansing, rinsing, pretreating, Cathodic Electro
Deposition (CED) using electrical current and ultrafiltration.
15
Further, the electrodeposition involves a step of conversion coating/pretreatment that generally
comprises of phosphating solution. Typically, in order to achieve sufficient adhesion and uniform
distribution of the e-coat, the metal part is subjected to a suitable pretreatment before entering the
process of Cathodic Electro Deposition (CED). This pretreatment involves step of providing
20 conversion/phosphate coatings as an intermediate anchor onto the metal surface and further waterrinsing. Conversion coatings often use environmentally harmful heavy metals, including nickel
and Iron phosphates. These substances generate phosphate sludge and wastewater containing
hazardous pollutants, posing disposal challenges and contributing to eutrophication, toxicity, and
environmental degradation, which is undesired. Additionally, the electrodeposition or e-coating is
25 a time-consuming process and involves high energy and high water consumption steps.
We claim:
1. A method of coating a metal substrate, the method comprising:
preparing, a metal substrate of a predetermined thickness by at least