Common problems in the use of aluminum paste
1.The coating surface has many particles
Reason analysis：
The use of incompatible resins, binders and additives
The external environment has poor dust-free conditions and the paint film surface is contaminated
The silver paste contains large particles of impurities that are insoluble in the system during use
The silver paste shows signs of oxidation
Solution：
Replace with more compatible resins, solvents and additives.
Improve the external environment and accelerate the drying speed of the paint film.
Replace the silver paste again.
2.Generate burrs
Reason analysis：
During the dispersion process, the rotational speed of the dispersing machine was too high, resulting in excessive shear force that damaged the shape of the aluminum sheets.
During the ball milling process of the silver paste, the milling time was too long, causing the aluminum sheets to become curled.
During the storage of the silver powder, oxidation occurred.
Solution：
Adjust the speed of the disperser to an appropriate level (adjust as needed based on the viscosity of the coating).
The silver paste should be sealed properly and stored in a cool and dry area.
The probability of ball milling problems is low because there are fixed processes and inspection standards.
3.The coating has turned black and lost its luster
Reason analysis：
Too much slow-drying solvent was used or the spray film thickness was too thick, resulting in high humidity of the paint film and slow drying of the coating.
The solvent used was too polar, damaging the metallic effect of the silver powder.
The acidity of the resin or additives was too high, causing the silver powder to oxidize in the system.
Solution：
Choose solvents with high evaporation rate and relatively weak polarity.
Replace the resin or additives. If the resin and additives cannot be replaced, it is recommended that the customer use coated silver paste.
Adjust the spraying technique to reduce the film thickness
4.Poor covering power (light-blocking property)
Reason analysis：
Insufficient silver paste addition
Poor compatibility between the resin and the silver paste, resulting in disordered arrangement of silver powder
Low solid content of the silver paste
The selected aluminum silver paste has a relatively coarse particle size (the finer the particle size, the better the coverage; the coarser the particle size, the worse the coverage.)
Oxidation and agglomeration occurred in the aluminum silver paste
Solution：
Increase the addition amount of silver paste
Replace the resin for experimental verification
Replace the silver paste for experimental verification
Reduce the rotational speed of the disperser
5.poor leafing
Reason analysis：
The high content of carrier acid esters or the extremely strong nature of the solvent causes the saturated fatty acids coated on the surface of the aluminum sheet to be damaged.
The incomplete coating of saturated fatty acids on the surface of the aluminum sheet leads to the corrosion of the silver paste.
Solution：
Try to use carriers with an acid value below 7.
Avoid using highly polar solvents.
6.The coating has lost its silver color
Reason analysis：
The resin used has a low ability to encapsulate the silver paste (or the solid content is too low)
The solvent in the system has too weak a dissolving power, preventing the resin from being fully dispersed
The amount of silver powder added exceeds the amount that the resin can accommodate
Some additives or solvents in the silver paste are incompatible with the main resin
Solution：
Replace with a more superior resin (with a lower TG temperature and greater softness).
Adjust the solubility of the solvent to better disperse the resin.
Try to avoid or minimize the use of silicon-based raw materials.
Reduce the addition of silver paste according to the actual situation.
7.Poor interlayer adhesion (paint peeling)
Reason analysis：
The used resin has insufficient adhesion to the substrate, or there is no adhesion between the resins.
The solvent is too weak and cannot fully disperse the resins.
The raw materials used contain a large amount of silicon-based substances.
The amount of silver powder added is too high, resulting in a reduction in the contact area of the resins before contact.
Solution：
Increase the viscosity of the paint and reduce its fluidity
Add the additive polyamide wax (also known as anti-settling agent: with thickening and anti-settling effects)
Select the silver paste produced by using additives with low density
8.The sedimentation rate is high.
Reason analysis：
The paint has a low viscosity and is too fluid.
The silver paste has a high specific gravity and a small surface area.
Some of the additives used in the silver paste have a greater density than the other raw materials in the system.
Solution：
Use solvents with weak dissolving power to blend and replace the silver paste that is less suitable for the system.
Bake to accelerate the drying of the lower coating or provide more drying time.