Tips before construction of pearlescent powder coating
Posted by: admin | on September 30, 2012
The pearlescent pigment having a colorless transparent, high refractive index, the directional foil layer structure, in the light irradiation, after repeated refraction, reflection and showing a sparkling pearl luster pigment. Not any permutation of the pigment platelets can produce crystal sparkle effect, in order to form a pearl and color, a prerequisite is the state of the lamellae pearlescent pigments are parallel to each other and arranged in rows along the surface of the coating.
Construction of varnishes and paints, pearlescent pigments follow the laws of physics, namely platelet pigment in the flow of the liquid will be in accordance with the direction of the flow of their own rows.
Spraying paints when the paint droplets collide with the flow action of the surface to be coated and expanded within the limited time, usually been able to meet the lamellar pigment-ordered flow requirements. Other construction methods for brushing, flow coating or dip coating, can also have a flow component can satisfy the alignment role of platelets.
After the viscosity increase due to drying, thixotropic or chemical reactions and the formation of the state of the pigments are arranged in rows is fixed. The color paint layer thick wet, low evaporation rate of the solvent, inappropriate the thixotropic or base construction temperature viscosity increase is too slow or too late, the pigment lamellae longer able to return to any order. This has resulted in a gloss loss. In contrary, the volatilization of the solvent in order to shorten the drying time of the coating to be beneficial. If wet coating reaches a certain thickness, and arranged in rows of the pigment platelets more difficult.
The gloss of the pearlescent pigment on the directional dependence of the other perspective, can be used to create many of the unusual shape decorative effect, e.g. the the dying effect or decorative wood with the surface shape of the shading colors. Pearlescent automotive coatings best construction method is a classic spray method, the best pearl effect after its construction.
Construction should pay attention to the problem:
- Pre-construction, the paint should Stir;
- Large-scale continuous operation for stand-coating the need for anti-settlement measures;
- Spraying should pay attention to gun distance, uniform walking speed gun, once construction should not be too thick