Powder Prowess in ACE Applications
Posted on Thursday, February 20, 2025
by Fiona Levin-Smith and Mike Chapman
The agricultural, construction, and earth moving equipment (ACE) market is worth tens of billions of dollars in the U.S. alone. Major OEMs, along with their smaller counterparts and tier suppliers, are looking for coatings that deliver performance, innovation, sustainability, and ease of process control.
Powder coatings in the ACE market are valued for their durability and resistance to harsh environments and technical performance is key. Rather than an industry-wide specification, most OEMs have their own performance and materials specifications and employ international standards, such as Japanese Industrial Standard (JIS) and American Society for Testing and Materials (ASTM) testing methods.
Integrity Test
Edge coverage is crucial when powder coating parts for ACE equipment because they are the most vulnerable to corrosion and wear. In harsh environments, equipment faces constant exposure to moisture, dirt, chemicals, and physical impacts. If the coating is too thin or uneven on edges, it can chip or wear away quickly, exposing the bare metal underneath to rust and corrosion. Good edge coverage ensures complete protection, maintaining the part’s structural integrity and extending its lifespan.
Mud, rain, fertilizers, and abrasive materials contribute to corrosion and coating breakdown. Powder provides excellent corrosion protection, creating a durable, uniform barrier over the metal surface. Salt spray testing exposes coated parts to a harsh salt fog environment, simulating corrosive conditions and evaluates the coating’s resistance to rust and corrosion.
Chemical resistance testing evaluates how well a coating maintains its appearance, adhesion, and protective properties when exposed to fertilizers, fuels, oils, cleaning agents, and other chemicals. Superb coating performance during immersion testing (submersion in specific chemicals and examination for signs of blistering, discoloration, softening, swelling, or loss of adhesion), and spot testing, (drops of chemicals applied to the coated surface, covered with a watch glass to prevent evaporation, and then evaluated after a designated time for damage like staining, gloss loss, or etching) is a must.
Likewise, the standard MEK rub test is a commonly used solvent attack test, as is high pressure washing to simulate the cleaning process with chemical detergents and high-pressure water without degrading. Taber abrasion testing, falling sand testing, impact resistance, and a basic crosshatch adhesion test are commonplace tests required of an ACE coating.
Naturally, the coated parts also have to look good. Accelerated weathering testing, xenon arc testing, and field testing all ensure the powder coating will meet required fading, chalking, cracking, and gloss retention requirements.
By employing strict technical testing, manufacturers can ensure that the powder coatings maintain their protective properties and appearance, even under the most demanding conditions. Powder formulations developed for the agricultural and construction equipment market ACE these tests. Pun intended.
Formulating Solutions
Strict technical requirements have led to innovations in recent years. Adhering to technical performance requirements is a given, but digging into problem areas ACE manufacturers face, from end use to internal efficiency, is where curious formulators and resourceful engineers have been able to deliver new value. For example, the latest powder formulations address the issue of coverage over high temperature sealants without compromising on performance. Powder application over the sealant allows for the product to cure together, creates a better seal, and greatly improves appearance. This is critical in sealing exposed areas of often very large components.
Powder formulations for heat sensitive substrates are also being used in innovative ways, namely the ability to cure quickly and evenly at significantly lower temperatures. This brings all the benefits of tough, protective thermosetting powder to heat sensitive applications like hydraulic assemblies and engines. The ability to powder coat any mechanical assembly that has seals or gaskets is key. The heat generated during a conventional cure would typically damage these parts, but with exciting new formulations, the powder film can be cured without introducing heat to the entire assembly. The powder still delivers the expected technical performance but cures rapidly and at lower temperatures, overcoming the issues associated with heat sensitive parts.
IR-refutable Advancement
Innovations and improvements for ACE applications extend beyond powder formulations. In looking at process, which is often extrinsically linked to coating performance, ACE companies are discovering what gas catalytic infrared (IR) oven technology, in combination with new powder formulations, can do for them.
Traditionally, convection ovens have been the go-to method for curing coatings in the ACE world. Now, gas catalytic IR is helping to solve problems and reduce costs.
Infrared radiation (IR), or infrared light, is a radiant energy that’s invisible to the human eye but can be felt as heat. These heat waves travel in random straight lines and are easily absorbed by inorganic surfaces such as powder coatings and liquid paint. Gas catalytic IR ovens are designed to maximize efficiency available from longwave infrared waves.
Medium to longwave infrared waves can be created using proprietary chemistry in the form of a ‘catalytic’ reaction. If liquid propane or natural gas is passed over a preheated pad coated with a special platinum coating, a catalytic reaction takes place. This reaction produces three things: heat (in the form of longwave IR), water vapor, and CO2. Nitric oxide and other unwanted gases are not produced.
Benefits extend beyond rapid, low temperature cure. The ‘3:1 Rule’ is often quoted when considering gas catalytic IR technology. It means that curing takes place in one third of the time that would be required in a conventional oven. So, if a conventional oven typically cures powder in 30 minutes, a gas catalytic IR oven would take only 10 minutes.
Reduced contaminants are another advantage. Conventional convection ovens require large movements of hot air to achieve a cure. Therefore, powder dust can become airborne and land on a curing part. Gas catalytic IR ovens have no air movement thus reducing dust contamination. Interesting fact—you can use a gel oven to “freeze” the powder on part edges to prevent powder on the edges from being blown off by the velocity of the convection air.
Gas catalytic IR technology, alongside heat sensitive powder formulations, are beneficial in coating parts such as hydraulic cylinders and cast steel components. Hydraulic cylinders provide a classic example. With convection curing, the whole cylinder comes up to the powder curing temperature. This temperature damages the cylinder’s internal O-rings. Once damaged, the rings will leak or have a shortened life span, and since they are hidden, the manufacturer does not know if the core of the coated cylinder is compromised until it is installed into the machinery and leaks hydraulic fluid.
Using gas catalytic IR cure and powder designed specifically for heat sensitive substrates, technicians used DataPaq probes inside the cylinder and noted the ability to keep the core temperature significantly lower than when using convection cure. With longwave IR, only the coating and a reduced depth of the cylinder wall is heated. The O-rings stay at ambient temperature. This ensures the same level of coating cure with improved core stabilization and a much-reduced reject rate.
With sustainability, performance, protection, and aesthetics at the heart of the ACE coatings market, the unique combination of technical prowess and innovation make powder coatings an excellent choice for ACE manufacturers seeking robust, sustainable solutions for protecting equipment investments.
Fiona Levin-Smith is vice president marketing and specification for IFS Coatings and Mike Chapman is chief technology officer for WolfRayet.