Thermal galvanization is the process of applying zinc to a metal. Galvanization is the term that refers to electrochemical processes. It got its named coined after the Italian scientist Luigi. Galvani
Pretreatment :The pretreatment is the process in which the object of treatment is removed from impurities it contains. So the foremost step in thermal galvanization is the cleaning of iron parts from impurities. There would be lot of impurities as sediment layer in it. To name few impurities grease, dirt, rust, oil, fat residues and mill skins. For instance pipes that supply water would undergo the process of thermal galvanization. To name some are steel pipes, copper pipes or stainless steel pipes that are coated with corrosion resistant materials. So these would be first removed in the cleaning process. In the above process, to remove the grease it would be degreased and then processed through a mordant bath and later to a flux bath. Lastly it is passed through a drier for drying. While the above process is carried out the mordant path becomes polluted with the iron particles. This later gets migrated to zinc bath.
The process results in iron or zinc particles to get layered over the product as well as under the bath. So it is vital to carry out cleaning of product in the zinc bath at regular intervals. The process of cleaning by using zinc bath at regular intervals would help the zinc layer to get sediment over the product and thus prevent its loss and there by results in good quality of product being produced.
Advantages of Zinc Coating :By acting as a barrier the coatings of zinc prevents metal from corrosion. Even after the barrier gets damaged zinc coating protect the metal by playing the role of anode. To state the fact even when zinc gets exposed to atmosphere which contains oxygen it reacts with oxygen producing zinc oxide. This zinc oxide would react with the water present in air to give zinc hydroxide. This later reacts with carbon dioxide which is present in atmosphere and as a result gives zinc carbonate. These layers of zinc carbonate gets deposited over the layer of zinc and results in protecting as a shielding layer from the metal being affected from corrosion.
Equipment Usage for regeneration of the flux bath :The above method of thermal galvanization has the greatest advantage of increasing the productivity of product without zinc loss but has a great drawback of the labor process is being much and the labor costs involved is high. To avoid this it is possible to install equipment for regeneration of the flux bath which was done in Netherlands. In the above process the fluxing solution is added with chemicals which combine with iron and gives iron hydroxide as result. After the above steps the process of filtration is carried out and processed through bath. The above process gets the greatest advantage by using hydrogen per oxide which helped in saving costs by saving electric power.
Electroless3 nickel-plating :In this technique layer of nickel- phosphorous alloy is made to deposit on metals without the usage of electric power. The technique uses the concept of regenerative process technology. By this technology the pH of the plating bath gets maintained using multi-compartment electrochemical cell. This technique also has an additional advantage apart from saving electric power. The additional advantage associated with this technique is that there is no need for treating and disposal of the spent bath waste. These results in cost cutting and thereby the technique helps in achieving maximum profit.