Epoxy coating, a product of natural and organic resin makes a very eco-friendly means of providing protective coatings. Resin is usually derived from coniferous trees and plants. Resin has very valuable characteristics that enable it to produce useful items like adhesives, varnishes, perfumes and epoxy coatings.
The process of polymerization is employed to manufacture epoxy resins. The organic epoxy resin is mixed with catalyzing agents, fillers, and pigments to turn into a dry powder. On being heated, it melts and causes a reaction that allows the formation of complex cross-linked polymers. On getting cured and dried, epoxy coating gives a strong, UV-resistant, and permanent protection to steel materials.
Fusion-Bonded Epoxy (FBE) Coating
On being heated to temperatures of 180 to 250°C, epoxy powder changes to a liquid state and as it flows on a steel surface it gets adhered to the surface. As the liquid comes back to solid state, it cross-links or “fusion bond” on the surface of the steel material permanently, thus offering an ever-lasting protection. This process is known as Fusion-Bonded Epoxy (FBE) Coating
Fusion-bonded epoxy coatings find extensive use in industries making corrosion-free steel pipes and fittings. As epoxy coating is derived from eco-friendly materials, structures with epoxy coatings are devoid of environmentally-hazardous solvents or substances that could come off and pose health and safety risks.
The Epoxy Coating Process
Epoxy coated steel bars are used for constructional projects. Here is the process of providing epoxy coating to steel bars:
1.Straight bars are cut to lengths of forty to sixty feet.
2.These are then blast cleaned for removing rust, scales and other contaminants from the surface. The output of blast cleaning is a rough surface finish called a profile. The profile increases the effective surface area of the steel thus providing better adhering for epoxy coating, which is subsequently applied.
Blast cleaning employs releasing of compressed air on to the steel surface, that forcefully pushes abrasives like steel grit, garnet, or coal slag on the surface, and causes pockmarks that cleanse and roughen the surface, while simultaneously increasing it surface area.
3. The profiles are kept on moving conveyor belts and preheated before being sprayed with dry epoxy powder. The dry epoxy powder is ejected from spray nozzles that are imparted with electrical charges and are automatically attracted to the already grounded heated bars. The dry powder melts and flows to the hot surface of steel bars, anchoring to the ribs and deformations in the surface, which were caused by the process of blasting. The heat causes a chemical reaction that converts the epoxy powder molecules into complex cross-linked polymers, forever changing the material into its final state.
A curing process of 30-second solidifies the epoxy coating, followed by an air or water douse for quicker cooling for easy handling.
The processes of manufacturing epoxy coating, and the coating process itself, are both efficient and environment-friendly. There is little material released to the atmosphere, very little waste, and no contaminants are released during the process. That makes epoxy coating a very desirable process for protecting metal.
