Storage and use of solvent-based aluminum paste
Aluminum paste contains a certain amount of slow-release mineral oil, additives, etc. to ensure its good storage stability and dispersion. Therefore, the storage of aluminum paste requires a well-sealed package and should be stored in a dry room (below 35 degrees). If a package cannot be used for one-time use after opening, it must be sealed intact immediately. Otherwise, if it is exposed to air for a long time, it will cause air-drying and oxidation, resulting in poor dispersion of the raw materials, granulation of the paint film, blackening and coarsening. After leaving the unused aluminum paste for a period of time, please be sure to test the sample before using it.
The key to the application and operation of aluminum paste lies in the dispersion link:
1.The aluminum paste is pre-dispersed in the solvent, added with an appropriate wetting agent, can be soaked for a period of time, then slowly stirred into a uniform and thin paste, and finally added to the pre-prepared paint, the best process effect can be obtained .
2.When dispersing aluminum paste, the commonly used solvents generally include: esters, ether alcohols, alcohols, aromatics, etc., among which esters have the best effect. In addition, it is also required that the solvent does not contain water, otherwise the aluminum pigment will easily react with water and cause instability. From this point of view, aromatic solvents generally have lower moisture content, which seems to be better.
3.The ratio of aluminum paste to pre-dispersed solvent is generally 1:1—1:2.
4.In the dispersing process of aluminum paste, high shear force should be avoided for stirring, which will easily cause the deformation of thin aluminum flakes, thereby affecting the appearance effect, so low speed and slow stirring should be used to disperse. The best dispersion speed and time should be determined through experiments.
5.Aluminum paste also has certain requirements for the paint. If the acid value of the paint is too high, it will affect the storage stability of the paint and cause the aluminum pigment to become black and rough.
Suggested aluminum paste addition ratio:
Adding ratio of colored primer aluminum paste: 1-4%
Adding ratio of aluminum paste for pure silver primer: 4-10%
Adding ratio of aluminum paste in single-layer metallic flash paint: 5-13%
Anti-corrosion paint and coil coating aluminum paste addition ratio: 10%-13%