Powder coating: deviation in color

Sometimes in the process of powder painting, troubles arise when the final coating has various defects after polymerization. To avoid these problems, it is important to understand their causes and how to solve them. Reducing imperfections in the painting process helps achieve a perfect finish. A frequent problem in the application of powder paint is the non-compliance of the color of the polymer film with the catalog or the unevenness of the color.

Probable reasons

There are many factors that can affect the color of polymerized powder paint. Despite the manufacturers’ efforts to ensure that samples are as consistent as possible with RAL or Pantone catalogs, unforeseen situations may occur during spraying and curing. Uneven application of paint on different parts of the structure can lead to differences in shades and imperfections. Also, an inappropriate level of gloss can occur when the polymerization oven is faulty or operates in the wrong mode for a particular paint.

Another serious problem is the spotting of other colors, often caused by paint contamination during powder changes in the sprayer or during storage. Fibers from brushes or rags used to clean the surface can also accidentally enter.

Solution

If different materials are used in the same design, this may also lead to a difference in color due to the characteristics of each material. A partial solution is an additional layer of paint. Different metal treatments can also affect color parameters, for example, chrome and galvanized surfaces can look slightly different under a polymer film. Therefore, metal surfaces need careful cleaning of dirt, grease and oxides before applying the primer.

Sometimes the main problem lies in the paint itself. To avoid this, the hoses of the spraying unit should be thoroughly blown before changing the powder. Also, different modes of polymerization can affect the color shade of the paint.

Sometimes the difference in color may be due to lighting conditions rather than a problem with the paint or the painting process.

In general, it is important to order paint from reliable suppliers, as pigments can vary from manufacturer to manufacturer. “Lacover” has many years of experience and a wide range of coatings, ensuring high quality products.