Zincatura a Spruzzo
The technological process and easy and simple execution, does not require complex equipment and is an excellent way to protect steel structures from corrosion, exploiting the characteristics of the sacrificial zinc. Just a modest overs of greatly increasing the life of the structures themselves at a competitive cost. The galvanizing spray is to spray molten zinc, finely pulverized, on the surface to be protected properly prepared with a suitable blasting to white metal (the degree SA3 SA 2,5 ). The spraying of zinc is performed with guns having a device for melting and pulverization and a power of zinc. The merger is ensured by an electric arc (fig.4) the fluid spray is generally dry air and oil, at a pressure of 0,27+0,54 MPa. Zinc is used in the form of wire, of diameter between 1,5 and 2,5 mm.
A modest investment, that defeats the rust, business generates profits and bears the benefits to individuals and to the public.
Rust is the main enemy of the iron, in Italy every year causes damage to € 20 billion. Everyone can see what state of degradation is an urban disfigured by rust because public administrators do not perform the necessary maintenance. This waste of resources can be reduced upstream in the design, using, in the construction of structures in iron for galvanizing spray.
The galvanizing spray is to pour for molten zinc on the steel surface finely pulverized previously sandblasted to white metal. The excellence of the zinc is to form a dense and adherent film that has a very low corrosion rate (the 10 a 100 times less than the basic iron). Zinc is anodic than iron or steel base and corrodes self-sacrifice in place to protect them from rust when the casing is damaged. The corrosion products of zinc coat the pores of the coating while the mechanical adherence depends on the kinetic energy of the particles of zinc. The spraying should be performed immediately after the blasting of the surface so that the same is still perfectly clean, dry and non-oxidized, in order to ensure the electrical contact zinc / iron, and then the anodic protection of the zinc. The duration of the coating depends on the thickness and the aggressiveness of the environment. Zinc ensures an effective corrosion in all environments in which the pH is between 6 and 12,5. The coatings obtained by spraying the electric arc differ from hot-dip galvanizing because they are more porous and composed of pure zinc. The porous coating accepts the sealants that penetrate into the pores and reduce the dissolution of the zinc.