Sinopigments pearl pigment should be well oriented in the film by giving ,moderate FLOW and PRESSURE .
The coatings with pearlized paints can be applied in almost all methods like:
---Spraying
---Roller Coating
---Air Curtain Coating
---Dipping
---Brushing
However, in order to achieve an optimum pearl effect in coatings, spray coating is the most suitable application method.
It is generally said that pearl pigment is better orientated than Al flake.
When the pearl pigment is pre-wetted, you should be careful of solvent shock. The use of general thinner is recommentdable.
Over-mixing, over-kneading or ever over-processing can lead to the fracture of the plate-like flake structure of pearl pigment into smaller light scattering particles, producing a less lustrous appearance in the film. Pearl pigments are destroyed, if it is dispersed like general inorganic pigments. In this case, pearl luster effect is weaker or is not generated. You should avoid overdispersing using a dispersing machine such as sand-mill.
When combining with pearl pigments, the colorants shoud be well dispersed. Poor dispersion of othe colorants sometimes cause pearl pigments to act as beads, which changes dispersion condition of other colorants (grow corpusle). This problem occurs expecially in the applications in paints and inks. Accordingly, you should be very careful of the dispersion of colorants. Insufficient dispersion of other colorants cause the particle size of other colorants to change due to pearl pigment.
Cleaning condition of processing machines is also very important to application. If the cleaning condition of the line is bad or paint puddle remains in the line, when pearlized paint is flow in the paint line, pearl pigment scrapes dust in the line, and this dust appears on the final product as foreign matter.
The pearl luster effect is produced by reflection and transmittance of light (Regular Multiple Reflection). Accordingly, in the case of opaque formulation, regular multiple reflection is hindered.
Color surfacer is sometimes used for car paint, therefore, it is important to check backgroud color. In the repair paint field, flat surface is required for good pearl orientation.
If some paint systems of (top) clear layer exist such as single top coat, double top coat and so on, the finish of final product is changed. |
