Jauhemaalaus

Jauhemaalaus, or powder coating, is a finishing process in which a dry powder composed of pigment and resin is electrostatically applied to a prepared surface and then fused by heat to form a hard, uniform coating. It is commonly used on metal parts to provide protection against corrosion as well as an appealing decorative finish.

The process typically starts with surface preparation, including cleaning, degreasing, and pretreatment (such as phosphating or chromating) to promote adhesion. Powder is then applied by electrostatic spray or triboelectric methods, causing the particles to adhere to the grounded surface. After application, the coated part is heated in an oven, usually at a temperature around 160–210°C, for several minutes to cure and cross-link the resin. The part is cooled after curing to seal the coating.

Materials used in jauhemaalaus include resin systems such as epoxy, polyester, polyurethane, and epoxy–polyester hybrids, with various pigments and additives to achieve different gloss, texture, and color. Typical coating thickness ranges from about 60 to 120 micrometers, with possible thicker applications for specialized parts. The finish can be glossy, matte, or textured, and it offers a wide palette of colors.

Advantages of jauhemaalaus include high material utilization with minimal overspray waste, low solvent emissions, excellent uniformity and coverage, strong abrasion and chemical resistance, and good environmental performance. Limitations involve higher equipment and curing temperatures, potential challenges with complex geometries or deep recesses, substrate compatibility constraints, and repair requirements (recoating or stripping if damaged).

Applications span automotive components, household appliances, architectural metalwork, bicycle frames, and metal furniture, among other metal finishing needs.