Tuesday, March 8, 2016 - Metallic Powder Coatings
Good2know that…apart from the diversification of metallic powder coatings on the basis of their appearance and production, their properties can also vary.
Gloss is objectively measured with a gloss meter according to the ASTM D-523 60 °, ISO 2813 or DIN 67530 standards. The principle of the gloss meter is based on measuring the specular component of light. Specular reflection is the mirror-like reflection of light from a surface, in which light from a single incoming direction is reflected into a single outgoing direction. In practice, gloss is usually measured at an angle of 60 °. However, it should be noted that the gloss of structured or metallic effects is more difficult to determine because of the coarse surface or the orientation of the metallic particles. Gloss measurements will therefore be performed at a number of degree intervals (series of +5° or +10°).
Exposure to abrasion or humidity
Some metallic coatings prove to be less resistant to the influence of harsh environments, like antique finishes or some dry-blends for example. In those cases, applying a transparent topcoat will ensure you of the proper protective properties without erasing the desired appearance or effects.
Extruded metallic coatings are fully recyclable in the powder coating process in contrast to dry-blend metallic coatings that are not. The effect of dry-blend powders can only be obtained with ‘fresh’ powder as the concentration of metallic particles will have changed in recycled batches. When using this recycled powder, “spots” or “clouds” in the coating may appear.
Bonded metallic coatings are recyclable if a certain mix ratio of new and recycled powder is taken into account.