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.
When you live in the Midwest and someone asks you about running a project for Hawaii, it tends to gain interest very quickly. Wisconsin may be pretty distant from Hawaii in both miles and climate, but steel in each location has a common enemy. Salt from the ocean water mixed with air and heat can wreak just as much havoc on steel as the salt combined with snow and wind up north.
Salt from the ocean water mixed with air and heat can wreak just as much havoc on steel as the salt combined with snow and wind up north. Most may not think of Hawaii as having a harsh environment, but the crew at Columbia Vehicle Group in Reedsburg, WI understood the challenge of making utility vehicles built to last in any climate. They turned to hot-dip galvanizing to help them achieve their goal.
While not much bigger than a golf cart in size, these small machines pack some serious work capability. With up to 5,200 lbs of payload and 14,000 lbs of towing, a machine built to work also needs to be built to take a beating. This is where galvanizing came into play. With the ever present salty air in Hawaii, painted versions of the utility vehicle can ding and chip removing the protection giving corrosion an easy entrance to start to break down the machines. Because galvanizing offers cathodic protection and a metallurgical bond that increases the Diamond Pyramid Number, it is much less susceptible to dings and scratches that cause corrosion problems.
The benefits of HDG are only the beginning of the story here. Working with galvanizers helps to ensure that projects can live up to the expectations. Proper ventilation in the design process was one of the steps where communication with the galvanizer can eliminate problems. Also, since an emphasis on capacity is key for Columbia Vehicle Group, they chose 10 and 12 gauge high strength steel in sections of the body to save weight. Knowing the design parameters ahead of time allowed the galvanizer a chance to plan dip times to avoid any distortion in the steel as the metallurgical bond is taking place.
The Hawaiian Airport previously had used a painted only version of the vehicles but, with the corrosive air, the machines lasted a little over 2 years before becoming too rusted to use. HDG has expanded possible avenues for Columbia Vehicle Group. Their ingenuity to see HDG as a solution to a corrosion problem of a customer thousands of miles away shows their care and willingness to supply the best product they are capable of. Brining HDG into the mix pushes their machines limits further. With the synergistic effect between paint and galvanizing, the duplex protection system can extend the life expectancy of each of the coatings by more than 2x, greatly increasing the life of the vehicles in this instance.
What does a project like this mean for the HDG market? As these vehicles make their way across state lines and over ocean boundaries, the unpainted versions act as rolling billboards for what HDG is capable of, and the duplex coatings shows just how versatile HDG can be. These utility vehicles may not bring the grandiose awe of a sky scraper, but they act as a reminder as to many of the little things in our world that can be enhanced by galvanizing.
This is in Hawaii, and the non-galvanized vehicle we sold this customer previously had rusted significantly in a similar timeframe