Safety & reliability advantages of Powder Coatings.  

Powder coating is one of the most popular processes used to apply a coating to a base material. It allows for a rapid and safe deposition of high-quality coatings. Although the experimentations with powder coating processes date back to before 1950, fluidized bed powder coating gained much popularity in the 1960s. In the 1960s and 1970s, the use of a gun that electrically charged the powder coating particles became popular for spraying the powder coating. Both methods are still in use and offer excellent advantages over other coating processes for suitable applications.

The process of applying powder coatings involves the use of a spray gun that not only propels the electrostatic paint but also gives it a positive electrical charge. The base material, on the other hand, is charged negatively which creates an attraction between it and the negatively charged powder coating particles. Once the attraction is established, both the base material and the powder coating particles are heated until the latter melts and sticks to the former. The base material is then allowed to cool down, creating a durable and long-lasting powder coating.

Powder coating materials have a significant advantage over liquid coating materials in terms of operator safety. When applying a powder coating, an operator only needs to wear a dust mask and safety goggles which is much safer than using liquid coatings. Additionally, many powder particle types do not emit fumes, making them relatively harmless if not inhaled or ingested. In contrast, paints contain volatile organic compounds (VOCs) or other solvents that can cause severe respiratory and neurological damage if inhaled excessively.

Liquid coatings can cause irritation or chemical burns if they come into contact with the skin. Furthermore, these solvents can be quite flammable, resulting in the risk of explosion or injuries. Powders do not cause burns when placed in contact with skin, and powders almost always do not require flammable solvents. 

The efficiency of Powder Coatings

Powder coating processes are usually more efficient than other coating methods for several reasons. One reason is that there is less overspray. This is because the electrically charged substrate has a negative polarity, and the electrically charged powder coating particles have a positive polarity, thus creating an attraction between the two. This reduction in overspray means that less coating material is required.

Another benefit is that the operator usually requires less time to spray the substrate. Adding to the powder coating process’s efficiency is the coating thickness’s magnitude that can be applied in one spraying. Coatings such as liquid paint spraying require the first coat to be used, then waiting for the dry-to-recoat time and cure time, another layer, and so on, until the desired thickness is achieved.

With powder coatings, greater coating thicknesses can be achieved in one application and curing cycle. The time spent waiting for curing and applying a subsequent coat can be spent coating another batch of parts or another portion of the structure.

Quality of Powder Coatings

Powder coatings have a high-quality finish. During the powder coating application, the charged powder coating particles automatically level themselves to a certain degree. This reduces the risk of uneven coatings when applying a liquid coating. Furthermore, powder coatings are not susceptible to running or dripping. This also decreases the possibility of uneven surfaces.

As mentioned, powder coatings require fewer layers than many liquid coating systems. This helps prevent the possibility of a powder coating having defects between layers.

Mechanical Properties of Powder Coatings

Powder coatings also have advantages concerning their mechanical properties. Powder coatings are known for being ductile enough to bend and yield with many of the base materials they have adhered to. Many powder coatings, such as epoxies, have excellent impact strength as well, which lessens the chance of chipping upon collision with other materials. Many different coating types are prone to this type of failure mode.

Abrasion resistance is also an advantage of powder coatings over other coating materials. This is partially a result of the bonding that occurs during the curing process.

Powder Coatings are Better for the Environment

Many coating materials (other than powder coatings) contain harsh chemicals. Solvents, such as VOCs, can damage the environment in which they are released and cause ozone to form when exposed to nitrogen and oxygen. This also promotes the formation of particulates in the air, creating smog that can cause damage not only to humans but to the surrounding wildlife as well. Furthermore, because the paint is applied wet, these VOCs can run off, escape the job site, be absorbed by the ground, and eventually find their way into streams, lakes and other water sources thus creating a severe threat to the environment. Because powder coatings do not contain VOCs, this risk is not present when used.

Powder coatings, when applied by a professional company, are more durable and have a lower tendency to loosen or chip away from the substrate they were applied to, compared to other types of coatings. As a result, the risk of solid particles contaminating the environment where the base material and coating were placed is significantly reduced.