Chromium-free Passivation Additive
LW-19 chromium-free passivation additive is a kind of colorless transparent and environmental protection additive. It applies the composite salts to form the uniform chemical conversion film on aluminum surface which can effectively enhance the coating film adhesion and corrosion resistance to the surface and the coating. LW-19 is chromium-free and in line with the green environmental protection requirements, can completely replace the traditional chromium passivation coating for aluminum surface treatment, it can also be used to spray or immersion.
1. Features:
1) Environmental protection: LW-19 is a kind of chromium-free and no heavy metals, non-toxic, no health hazards acidic liquid additive;
2) Simple: Simple process, wide control range, convenient control, only need to control the bath solution PH value of 2.8-3.8;
3) Energy-saving: Operation at room temperature, bath make-up applies running water, no need to worry about the inconveniences caused by application of pure water;
4) Performance: Bath solution is stable and the coating film is of no color (transparent), it is also applicable for crystalphoresis pretreatment.
2. Bath Make-up:
Name | Quantity | Unit |
LW-19 | 8-10 | g/L |
Water | Balance | |
3. Operating Conditions:
Name | Quantity | Unit | |
PH | 2.8-3.8 | ||
Time | 60-180 | seconds | |
4. Process Control:
Process flow (immersion or spraying):
Rinsing → Degreasing → Rinsing → Rinsing → Rinsing → Passivation → Rinsing → Dry
5. Solution Maintenance:
1) After a period of production, LW-19 should be replenished in time for the passivation performance of solution will get down caused by the content decreasing;
2) The PH of solution is the key factor to affect the quality of coating film, when PH goes too high resulting in very slow coating film forming speed, please replenish LW-19 and mix evenly, then solution can be used normally again.
6. Precautions：
LW-19 is a kind of acidic and relatively safe liquid, use rubber gloves when contacting.
7. Packaging and Storage:
Package: Plastic barrel (25kg/barrel,1000kg/barrel)
Storage: Suggested to store in cool, dry and well ventilated place; away from fire and heat source.
