The primary purpose of industrial coatings is to protect metal surfaces from corrosion but there are instances when it turns out to be an aesthetic improvement. One type of industrial coating that is often used on metal surfaces is paint that can prevent corrosion of metal arising from its exposure in the environment. Corrosion can occur when metal is exposed to moisture or when the surface is contaminated by chemicals.
How corrosion is prevented through industrial coatings
Atmospheric corrosion depends on a number of factors that include relative humidity, temperature, chemical contaminants and location. Rain, condensation, mist and other forms of humidity results into the metal surface getting wet. When the critical value of humidity is exceeded, corrosion will occur. There is no standard critical value of humidity because it depends of the quality of metal and other related factors; however, once corrosion starts even a much lower relative humidity will activate the process of corrosion. If there are chemical contaminants in the water, corrosion occurs at a faster rate. Chloride and sulfur dioxide are two components found in the atmosphere that accelerate corrosion and more so at higher temperatures. Usually chemical corrosion of the metal surface is relatively even on all areas but when metal is exposed to chloride ions in sea water, it can cause pitting. The ability of industrial coatings to protect metal surface against corrosion depends on its anti-corrosive pigments and how well it adheres to the surface. Additives and pigments found in industrial coatings can enhance anti-corrosion properties and prevent both cathodic and anodic reactions.
In order to prevent a cathodic reaction, it is important for the industrial coating to prevent oxygen and water from reaching the cathode. Industrial coating acts as the insulating material that slows down the movement of oxygen and water on the metal substrate. Epoxy paint which is a popular type of industrial coating can form a tightly bonded coat that protects the metal substrate in severe conditions. Industrial coatings also have to provide sufficient protection against anodic reactions that forms under the paint coat. In order to stop anodic reactions, dissolving of iron ions must be prevented through protective layer of active anti-corrosive pigments that are anodic inhibitors.
How to ensure the durability of industrial coatings
A successful industrial coating depends on several factors that include the corrosion resistance of the metal substrate and how the surface has been prepared prior to the application of coating. Corrosion resistance is influenced by the time, place and duration of surface preparation, maintenance coating possibilities and the time, place and method of assembly. On the other hand, the durability of industrial coatings used depends on the surrounding, variations in season and interruptions during the process. Surfaces that cannot be treated after assembly and installation should be treated prior to the application of coating. Surface preparation will not be required if the metal substrate is resistant to corrosion. Cleaning and surface treatment improves adhesion and the durability of coating. To ensure a successful coating process, it is necessary to choose the appropriate surface preparation.