Fifty Shades of Gray: Paints and Coatings
Driven by end users who demand a more durable finish, greater throughput and adherence to environmental regulations, the paint and coatings industry has drastically changed over the past ten years.
Federal Regulations: The paint and coatings industry is subject to federal regulations. Volatile Organic Compounds (VOCs) are solvents that get released into the air through the paint application process. This can be from the degreasing operations or paint application stage and lasts through much of the curing process.
Solvents can cause immediate symptoms, including headaches and dizziness, which is why proper breathing/filtering equipment is required and as the solvents evaporate. The solvents can react with sunlight to create low level ozone resulting in pollution and smog. The Federal Government has enacted national regulations for certain industries, such as automotive collision repair segment stating that at minimum the VOCs for certain product categories, such as primer surfacer, cannot exceed a certain value. Individual states, cities, and counties where air quality agencies exist, have the ability to enact more stringent regulations depending on its individual attainment or non-attainment status.
Another Federal regulation which impacts the manufacturing and coating operation is hazardous air pollutants (HAPs). (1)
Local Regulations: As local agencies have increased the monitoring of paint and coating application process, the paint and coating industry has embraced more environmentally friendly formulations and technologies such as low VOC or waterborne paint products. While there are still areas that do not have VOC regulations, there still may be total emission regulations for a manufacturing or coatings applications facility imposed by the local permitting agency. This not only could include VOCs from every operation (cleaning through painting), but HAPs as well.
Long ago, trailer manufacturing was a cumbersome and unwieldy process. As the trailer manufacturing process has streamlined into large scale manufacturing, the paint and coating industry has modernized as well. With the changes at the manufacturing level came the ability to increase throughput and in some cases this meant that the coatings technologies being used may no longer fit the operation. The luxury of having “as much time as was needed to apply paint and let it dry” was gone. Coatings manufacturers had to develop fast-drying products that could be applied in combination with each other, or would dry faster when baked or force-dried. Some manufacturers changed from a slow drying alkyd enamel coating to a fast drying urethane coating, which in the right application environment, can be made to dry even more quickly. Other manufacturers have switched to a primer that can be top coated with color in 15 – 30 minutes instead of an hour.
Some manufacturers have added bake ovens to its spray facilities to improve overall productivity.
Keeping up with the Joneses isn’t exclusive to upscale, trendy neighborhoods; manufacturers want boasting rights as well. Currently, color and finishes are a hot commodity. Consumers want their trailer to match a boat or truck including the metallic sheen or the pearly, opalescent coat. Trailer manufacturers have expanded their color and finishing options to keep up with demand. If you want a "tuxedo black" trailer with a "frozen black" velvet finish, chances are a highly-competitive trailer manufacturer will want to be the first manufacturer to post that custom trailer to its Facebook page.
As with any industry, there are manufacturers who will readily embrace and implement innovation. These early adopters might gain a competitive advantage which might drive manufacturers to update or change processes.
Preparation is Key
Abraham Lincoln said, “If I had six hours to chop down a tree, I would spend four hours sharpening the axe.” As Honest Abe cleverly quipped, preparation is critical. For a better looking, longer lasting or better performing finish, Steve Podlas of PPG advised spending time preparing the surface. “The worst thing you can do is apply primer or topcoat paint to improperly prepared bare steel substrate (greasy, oily, etc.) or over rust.”
Podlas recommended a few simple steps: degrease, sand blast or abrade or chemically pre-treat (although this step is not always simple). Properly preparing the material will allow the paint to adhere to the substrate. Once prepped, apply the primer or primers and top coat per manufacturer’s recommendations.
Following the recommended process for your particular substrate will provide you a more durable finish.
Paint and Coatings’ Future
Podlas predicts the future of paint and coatings to include:
1) Polyaspartic Coatings. The fast curing feature of these coatings can provide significant, money-saving productivity improvements, along with high-build, low-temperature curing, and abrasion and corrosion resistance. Polyaspartic coatings are either low or near-zero VOC.
2) Preemptively Addressing Corrosion. Zinc rich primers provide outstanding corrosion resistance, especially in aggressive corrosive environments. The sacrificial zinc binds with the metal substrate. As a result, if the trailer paint is dinged or gouged, the zinc blocks corrosion. Zinc primers are available in powder or liquid. By nature, zinc is does not respond well to high temperatures; however, powder zinc is a high-bake product.
3) New Urethane Technologies: New urethane technologies provide smoother finishes and gloss with lower VOCs. Urethane is also known as polyurethane. Polyurethane is now one of the key ingredients in high-performance coatings that can provide excellent protection against wear, corrosion and all forms of damage. (2)
In the 1990s a new polyurethane hybrid called PU-polyurea elastomers was used by the U.S. Navy as a highly durable coating for their decks. This coating method provides a durable composite that is resistant to abrasion with metal surface corrosion and brittleness resistant in connection with the bed liners with thermoplastics.
Polyurethanes are made by combining two or more liquid streams. The first ingredient stream, such as polyol, consists of blowing agents, surfactants and catalysts, and so forth. The other component is isocyanate also known as "iso" or "A-side." The mixture of additives with polyols is called "poly" or "B-side." This combination may also be called "resin blend" or simply "resin." This blend may be combined further with fillers and pigments as well as other components. Polyurethane is a major component in top coatings because of its ability to be made into varying hardnesses and densities by modifying the polyol or isocyanate additives. (2)
5) Environmentally safer chemicals. Just as many over-the- counter chemicals are becoming more environmentally friendly, manufacturing products are making the switch as well. PPG Industries introduced an ecologically sound product; CFX744 - CorroKleen™ 44 Rust Remover. This is a citrus based product designed for use on ferrous metals to remove mild to moderate rust and mill scale. CFX744 is free of phosphates or other strong acids, making it an alternative to traditional rust removers, sandblasting or grinding.
6) More waterborne offerings with better performance. The VOC content of waterborne paints is significantly lower than conventional solvent-based paints, thereby reducing VOC
emissions. Waterborne (or latex) paints consist of synthetic resins and pigments that are dispersed in water by surfactants. They also contain small amounts of coalescing solvents. Waterborne paints dry when the water evaporates. The coalescing solvents allow the resin particles to fuse together as the water evaporates to form a continuous coating. Waterborne paints must be protected from freezing and applied at a minimum temperature of 50° F. (3)
Waterborne paints reduce VOC emissions and worker exposure to hazardous air pollutants. Depending on the type of paint used, waterborne paints can also reduce the amount of hazardous waste generated.
varying hardnesses and densities by modifying the polyol or isocyanate additives. (2)4) Environment1