Humidity and Airborne Contaminates: How to Prevent Issues During the Powder Coating Process
Fluctuations in humidity, as well as airborne contaminates can create huge problems during the powder coating process. Understanding their cause, the issues that they may create and how to eliminate their potential for damage is essential.
Humidity
When there are fluctuations in humidity, it can contribute to serious defects in a finish that has been powder coated. The powder that is used is sensitive to moisture, and excessive humidity can create clumping in the powder. As this occurs, the ability to actually spray the powder fluidly and consistently is restricted, which causes balls of powder to begin to clog the pump as well as the other equipment used.
Excessive humidity, in addition to excessive dryness is able to cause a serious of issues with electrostatics, which make it difficult, and in some cases impossible to create a charge for the powder particles that are being sprayed. Too much, or too little, moisture in the air can serious issues and failing powder adhesion to the item being sprayed.
Contamination Due to Airborne Particles
Any type of airborne contamination is able to create a huge issue for the industry of powder coating. Grit, fibers, shop dirt and other types of metal particulates from any other type of facility processes are able to create bumps or protrusions into the finish if they are allowed to infiltrate the entire powder system, as well as the paint spray booth.
When airborne contamination occurs, it can compromise the appearance of the part that is being coated. There are a number of different degrees of concern in the different industries, but the majority of them will not accept very much particulate being present in the actual coating. Depending on the actual application of the powder coating, such as home appliances, bicycles and office furniture, the presence of any type of visible particles on the surface is likely completely unacceptable, which can result in, at the least, an extremely dissatisfied consumer.
One of the advantages offered by powder coating is that there is minimal wasted material. Whatever powder is not adhered to the actual part being sprayed will fall to the floor of the booth, where it is able to be collected and then reused for another project. However, there is also the possibility that dirt or particulate will be collected with the powder, which can build up in the reclaim system. This system is able to send the powder through a specially designed screen that will remove any evidence of particulates or fibers, allowing a clean powder to be fed into the hopper.
Understanding these two potential risks to the powder coating process is essential for those completing the work, as well as individuals that are having powder coating work completed.