Have you noticed that the powder coat/film on your products isn't uniform? Read on and discover some of the factors that could have caused that problem. Use this information to talk to the fabricator or select another more experienced fabricator for future batches of products.
High Output Speed
Fabricators normally set the powder coating machine to release the powder mix at a predetermined rate. The resultant powder coat can lack uniformity in case the machine was programmed to release the powder at a very high rate. Such a high rate can prevent the powder from spreading out quickly enough to settle on the substrate in a uniform way. This defect can be avoided by using a slower rate of powder discharge.
Surfaces that are going to be powder coated need to be prepared carefully so that the powder coat will adhere to the surfaces. For example, all impurities, such as grease and oil, must be removed before the item is taken into the powder coating chamber. Otherwise, the oil may prevent or attract more powder than is required at a particular spot. Different powder coating techniques require different pretreatment steps. For example, some techniques call for the creation of static electricity on the surface so that the electric charge will attract and hold the powder coat before the item is put in an oven to cure. Fixing the pretreatment shortcomings can, therefore, allow the coat to adhere uniformly.
Incorrect Film/Colour Mix
Powder coats contain different types of ingredients, such as metallic additives, to enhance the perceived colour depth of the coated surface. These different ingredients are programmed in layers. A mistake in the film setting of one of those components can result in lack of uniformity in the resultant powder coat. This problem would have been avoided if the fabricator had run sample parts to ascertain the appropriateness of the film thicknesses selected.
As already mentioned, powder coated products are placed in an oven to cure. The coating can lack uniformity in case the curing conditions aren't suitable for the application. For instance, some of the powder can drop off sections of the substrate if the heat in the oven doesn't reach the furthest points of the product.
It is evident that lack of uniformity in powder coats can often be traced to mistakes in the different steps of the powder coating process. It is therefore essential for you to select a powder coating professional carefully. Such a person will take all the necessary precautions to deliver a flawless powder coated product.