Once the metal is cleaned, treated, and painted, the strip is rewound into a coil size prescribed by the customer. From there, the coil is removed from the line and packaged for shipment or additional processing.
After the primer is applied and cured, then the metal strip enters the finish coat station where a topcoat is applied. Topcoats provide color, corrosion resistance, durability, flexibility and any other required physical properties. Like primers, the topcoat is cured using thermal cure ovens.
Oven
Coil coating ovens can range from 130 feet to 160 feet and will cure the coatings in 13 to 20 seconds.
During this stage, the strip enters the prime coat station whereby a primer is applied to the clean and treated metal. After the primer is applied, the metal strip travels through a thermal oven for curing. Primers are used to aid in paint adhesion, improve corrosion performance and enhance aesthetic and functional attributes of the topcoat.
S Wrap Coater
The S wrap coater design allows for primers and paints to be applied to the top and back side of the metal strip simultaneously in one continuous pass.
The cleaning and pretreating section of the coil coating process focuses on preparing the metal for painting. During the cleaning stage, dirt, debris, and oils are removed from the metal strip. From there, the metal enters the pretreatment section and/or a chemical coater whereby chemicals are applied to facilitate paint adhesion and enhance corrosion resistance.
Dried-In-Place
In this stage a chemical that provides enhanced corrosion performance is applied. This treatment can be chrome free if required.
The accumulator is a structure that adjusts up and down to store material, which makes continuous operation of the coil coating process possible. This accumulation will continue to feed the coil coating processes while the entry end has stopped for the stitching process. As much as 750 feet of metal can be collected.
Although resistant to rusting, durable galvanized steel can still get dirty or stained.
The zinc oxide coating of galvanized steel acts as a critical barrier to protect the underlying steel from corrosion. To preserve aesthetics, regular cleaning is recommended. However, different filth and/or contaminates require different methods of cleaning, while certain chemicals or processes can ruin the galvanized finish.
With more than 40 galvanizing operations located throughout the U.S. and Canada, AZZ has been committed to developing hot-dip galvanizing processes for decades. Their extensive experience and expertise as a leading industry provider make them the preferred partner when it comes to maintaining your galvanized steel. As such, AZZ has compiled a list of tips for cleaning specific stains or debris from galvanized steel.
Whether it’s using a bristle brush or the proper PSI water pressure to remove common dirt and mud, to determining whether water storage stains merit stripping and re-dipping or just a simple ammonia cleaning solution, to which products are best suited to remove contaminants such as permanent marker, oil, grease or spray paint, these tips from AZZ can help ensure galvanized steel looks and performs like brand new for years to come!
At AZZ Galvanizing and Plating – Milwaukee, precision and performance come together to deliver reliable corrosion protection and surface finishing solutions.