New Trends in Powder Coatings

By Kevin Biller

It’s that time again, powder coating friends—time to examine new trends in our esteemed industry. Before delving into a granular look at the cool technical and market trends, we’ll have to first analyze some of the macroeconomic trends we have been experiencing.

Many of us hoped for the return of the old, pre-COVID “normal” before the pandemic and all of its fallout that turned our world upside down. ChemQuest’s CEO, Dan Murad, lamented on this topic in a keynote speech at a coating conference when he said, “If you’re waiting for the world to return to the ‘old normal,’ you’re probably in for a surprise.” That doesn’t mean we don’t have exciting things to look forward to in the powder coating industry, we just have some additional challenges to get out of the way first.

Not-so-good Trends
A number of issues, some anticipated and others unforeseen, have impacted the global economy and the chemical industry in particular. Shipping, inadequate raw material production, and demand outstripping supply are major troubles facing the topsy-turvy chemicals and coatings industries. In addition, labor shortages are pervasive across all levels of the supply chain.

Shipping issues have been exacerbated from many directions: a dearth of containers, over-loaded ports, and an acute shortage of trucks and truck drivers. Pre-pandemic, shipping containers and truck drivers were already in short supply. Following the original slow-down due to COVID, demand spiked, and the shipping industry was caught off-guard. A major reduction in industrial output coupled with a significant rise in demand for consumer goods was largely responsible for this. Ships had been hauling TVs and electronics from Asia instead of raw materials needed for the chemical industries. When industry rebounded there were few ships and containers in place to move the chemical intermediates, resins, additives, and pigments needed to produce coatings and other allied products.

On top of this, the production of basic chemicals was unable to respond in a timely manner when demand surged. When COVID hit, the chemical industry significantly cut back production. The oil refineries that dot the Gulf Coast almost immediately reduced output to 60% in April-May 2020. A remarkable “V-shaped” recovery followed in July, and demand skyrocketed. Refinery production struggled to respond. Keep in mind that the two major outputs of refineries are ethylene and propylene, the building blocks of most of the organic raw materials used in coatings.

Just as the output of the refineries was approaching prepandemic levels, winter storm Uri hit the Gulf Coast and destroyed scores of chemical production facilities throughout Texas and Louisiana. The devastation of these operations cannot be overstated. Many are just getting back online and just recently have returned to pre-COVID production levels. This has caused unprecedented interruption in the supply chain, causing prices to spike and lead times to increase from the normal two to three weeks to six months or longer.

In addition, labor shortages have plagued our industry. Besides the afore mentioned scarcity of truck drivers, powder manufacturing operations cannot fill job openings. This perplexing issue doesn’t appear to have an easy fix. Job openings are plentiful; however, at the same time, unemployment is hovering around 5.4%. Powder manufacturers have increased wages, and some are giving sign-on bonuses, yet positions remain unfilled. Even the economic experts don’t have an answer to this conundrum.

Mergers and Acquisitions
Mergers and acquisitions have exploded at unprecedented levels. In 2020, companies had excess cash and, boy, did they ever spend it on acquisitions. In the coatings industry, PPG bought Tikkurila, Alpha Coatings, Worwag (Germany), Hemmelrath (Germany), Whitford Worldwide, Dexmet, Versaflex, and Ennis-Flint. In 2021, Sherwin-Williams bought the German paint maker Sika. Axalta bought U-POL Holdings, an auto refinish paint manufacturer. AkzoNobel acquired Grupo Orbis, a South American paint conglomerate, and also Titan Paint, SAU in the Spanish market, and Stahl Performance Powder Coatings. ProTech bought the British paint maker Excalibur Paints & Coatings, although this was not unusual as ProTech has acquired over twenty-five coatings companies over the last three decades.

What is noteworthy are the key acquisitions that have brought unique technology. PPG’s acquisition of Alpha Coatings brought them ultra-low temperature cure powder technology, new to their portfolio. And AkzoNobel added much-needed UV curable and low temp powder technology with the acquisition of Stahl.

The raw material producers were even more active on the M&A front. Two major suppliers of powder resins were gobbled up in 2021. Covestro purchased DSM’s coatings resins division and Thai chemical giant PTT acquired allnex’s resins business. Pigment producers have further consolidated with the merger of the Canadian-based Dominion Colour and Lansco Pigments. In addition, Clariant has been purchased by Heubach, and BASF’s pigment division was acquired by Sun Chemical. Additives and specialty chemical suppliers have also been extremely active on the M&A front. Major acquisitions were made by Lanxess, Krahn Chemie, Altana, ICP, INEOS, Chroma Color, Thiele Kaolin, ASK Chemicals, and Arkema.

Technical Trends
Powder coating technology has not stood still in 2021. R&D efforts by powder makers are coming to fruition after incubating in the lab for years. Exciting new developments are emerging in many directions, including the automotive, architectural, and furniture markets. Let’s review a few of the biggest innovations.

Automotive
The automotive powder field is alive and well after a dormant decade or so. With the advent of the electric vehicle—first perfected by Tesla—and more recently being vigorously introduced by Ford, GM, Audi, Volvo, Toyota, Nissan, Hyundai, and newcomers such as Lucid Motors and Rivian, the automotive landscape has significantly changed. Innovation in automotive engineering spawns a new set of coating requirements. Specifically, the coating requirements for the electric power train are extremely conducive to the use of powder.

Because of their toughness, chemical resistance and high dielectric strength, epoxy powder coatings are an ideal fit for bus bars, stators, rotors, and the racking and covers for battery packs. In addition, powder coatings can be easily applied as a thick single coat, ensuring a very durable and consistent finish. Transitioning powder technology historically used for industrial transformers, motors, and generators to modern EV power plants has been a relatively smooth process. This represents a very large market as the amount of coating required for these electrical infrastructures is roughly the same as the exterior of the vehicle. Experts forecast an amazing 20.1% annual growth rate over the next five years for automotive powders used in EV applications.

It is not only parts associated with the electrical infrastructure of EVs currently being powder coated. In addition, automakers consider powder coating as the first choice for suspension and cooling system parts because of its efficiency, durability, and minimal environmental impact. Although since the early 2000s, traditional North American automakers have shunned the use of powders as body coats (primer surfacers and topcoats), upstart automotive manufacturers in Asia have embraced the use of powder color topcoats. Entry level car makers such as Tata Motors (India), Chery (China), and Yitou Biaoma (China) have been using super durable polyester topcoats over electrocoat or electrophoretic paints for the last few years. In addition, the Citroen spin-off, DS Automobiles, has been evaluating dead matte powder coatings as topcoats for their DS3 and DS4 models.

Powder Application Processes
“Dry-on-Dry” powder coating schemes have been around for years. Difficulty was experienced with the production scale-up of true dry-on-dry powder coatings processes due to the interspersion of disparate powder particles (primer and topcoat) during application. Recently powder manufacturers
have finessed this concept into a four step process consisting of:

1. Application of dry powder base (primer).
2. Gelation with infrared heat.
3. Application of dry powder topcoat.
4. Full oven cure.

This added gelation step yields a two-coat system that combines excellent corrosion resistance with outstanding UV durability.

Powder-in-Mold-Coating (PIMC) has been around since the late 1990s and is used in a process known as compression molding. A thermosetting powder coating is electrostatically applied to a preheated tool/mold designed to fabricate a plastic item. The plastic, usually in sheet form, is introduced to the mold and the tooling is pressed together. Heat is applied and the coating and plastic substrate are fused together to create a finished part. Recently fabricators have developed molds that simulate a carbon fiber look surface in the powder coating that has pleasing aesthetics and excellent toughness and durability.

Architectural Coatings
Hyperdurable powder coatings are gaining momentum in the marketplace. Major skyscraper projects have been using fluoropolymer-based powders
to provide outstanding UV durability. Most notably are 55 Hudson Yards in Manhattan, the Stratus Building (9th & Lenora) in Seattle, and PNC Plaza in Pittsburgh. These powder coatings are based on a special fluoroethylene vinyl-ether resin and are cured with an aliphatic urethane crosslinker. This technology exceeds the rigors embodied in the AAMA 2605 and Qualicoat Class 3 specifications and can withstand intense UV and environmental exposure for upwards of ten years or more.

Raw Materials
On the raw material side of the equation, novel types of gloss reduction and matting have been developed. Bernhard Resch of Evonik reports on a novel spherical grade of amorphous silica that can reduce gloss from 90 GU (gloss units) to well below 40 GU. This unique functional filler, dubbed Spherilex, is inert, low in specific gravity, and in many cases can improve the impact resistance and flexibility in the coating. Calistus Ezeagu of allnex introduced a novel matting resin designed for cure with β-HAA (hydroxy alkyl amide) crosslinkers. This polyester material produces an attractive matte finish of 10-15 gloss units that possesses good color and over bake stability. The resultant coatings exhibit excellent flexibility and film smoothness.

Smart Powder Coatings
Some of the more interesting developments encompass powder coatings that respond to environmental stimuli. The Spanish powder manufacturer Adapta Color S.L. has developed a photocatalytic powder coating that absorbs hazardous environmental nitrous oxides and converts them to harmless nitrates in the presence of UV light. These same people have also developed a powder coating that repels insects, most notably mosquitoes that can carry disease-causing bacteria and viruses. Laboratory testing has confirmed that this coating technology provides a 62% reduction in the Adedes aegypti mosquito, which is known to transmit dengue, Zika, and yellow fever in tropical climates.

Heat Sensitive Substrates
The powder industry has expressed a renewed interest in technology designed to cure on heat sensitive substrates such as composites, molded plastic, assembled and heavy gauge parts, natural wood, and MDF. This has spawned a rebirth of UV curable powder technology. Mainstays such as Keyland Polymer have been formulating and supplying UVPCs since the 1990s. Recently PPG and AkzoNobel have made investments into low temperature cure powder technology. PPG purchased industry stalwart Jeno Muthiah’s powder coating company, Alpha Coatings, and with it a treasure trove of low temperature cure technology and commercial experience.

AkzoNobel acquired Stahl Performance Powder Coatings, located in Barcelona, specifically for their low temperature cure powder technology which includes both thermosetting and UV curable technology. In addition, Akzo has recently opened a powder technology center at their stunningly picturesque location in Como, Italy. They have future plans to open similar powder coating R&D centers in the U.S. and Asia. Targeted substrates include MDF, plywood, thermoplastics, and composites. A wellspring of innovation has recently blossomed in the powder coating industry. Much of it was originally developed by smaller, more nimble firms (rather than traditional industry behemoths), and recently absorbed by multinational paint makers. Upon further analysis this dynamic makes abundant sense—have the agile, entrepreneurial guys create new technology and when the market is truly ready, have the big guys buy it and deliver it using their vast sales and marketing resources. If all goes well, it becomes a win-win-win situation. The little guy receives vindication of their hard work and hopefully with that a nice payout, the big guys get technology that they’re too bloated and bureaucratic to create, and the coating user enjoys the best technology for their product lines. Not too bad.

Kevin Biller is president at ChemQuest Powder Coating Research.