Time Proven Reliable Dacromet Coating For Corrosion Protection
1. Product Information
- Thin dry-film, non-electrolytic, self-lubricated or not
- Water-based chemistry
- Passivated zinc and aluminium flakes in a binder, patented chemistry
- Binder contains chromium oxide (Cr3+ and Cr6+)
- Metallic silver appearance
2. Composition/information on ingredients
JH-9392 is made up of three packs: A,B and C;
Pack A: It is silver gray slurry that mainly chemically combined with super fine flake Zn, super fine flake Al and ethylene glycol. The radius-thickness ratio of Zn plate is 60~100.
Pack B: It is the solvent of the coating colored in orange-red and in water solution, which contain the Cr6+.
Pack C: It is the tackifier of the coating which mainly made up of cellulose white or yellowish powder.
3. Coating Process
3.1 Mix Ratio
Pack A:16.0 kg
Pack B:24.0 kg (the quantity can be increased appropriately if spray coating)
Pack C:0-50 g (according to different viscosity demand )
3.2
| Mixture Method | |
| Before Mixture, Keep weighted A&B into the water bath at 25±2℃ , then stir A to make metal slurry disperse uniformly by frequency mixer ,after A is fully evenly dispersed, reduce the agitating speed to 60r/min, and add B. 3.2.2 | Add B to the stirring A slowly. At the moment ,the barrel temperature will go up,when it reaches 35℃, startup refrigerating device to keep the barrel temperature constant at 35℃. | | | | | |
| |
3.2.3
Stir the mixture about 1~2 hours fast after B added, then add C. C should be powdered if lump exist.(The barrel temperature should not be lower than 30℃, otherwise C will not be dissolved sufficiently .)Then stir 12 hours continuously.
3.2.4
The coating should be filtrated by 80~100 mesh stainless steel screen before pouring into dip barrel.
3.2.5
Temperature control device should be equipped with dip barrel to keep the temperature of coating at 22±2℃.(If temp. is too high, the paint is liable to deteriorate, and viscosity will be effected.) The coating should be stirred circularly to keep evenly dispersed.
3.2.6
Test density,PH,Temperature,Viscosity and Cr6+ content of coating every 8 hours if operate continuously.
4. Technical data
| No. | Item | Data |
| 1 | PH | 3.8-5.2 |
| 2 | Cr6+ | ≥25g/L |
| 3 | Specific gravity | 1.30±0.05 |
| 4 | Viscosity | 20~60s(Spray Coating) ; 60~90S(Dip-Spin Coating) . 20℃ Zahn 2# cup |
| 5 | Operating temperature | 22±2℃ |
5. Mix Diagram
Caution: Temperature should be controlled in above operation.
6. Coating Process
6.1 Degreasing
The workpiece should be degreased if there is oil on the surface. There are three processing methods:
1.High temperature
2.Neutral water-base degreasing agent
3.Organic solvent such as methylene chloride.
6.2 Derusting
The workpiece can not be coated if there is rust or burr on the surface.The best processing method is shot blasting. The corrosion resistance of coating will be effected if acid cleaning adopted.
6.3 Coating
The workpiece afer degreasing and shot blasting should be coated through Dip-Spin coating or Spraying Coating.
6.4 Pre-heating
The workpiece after coated should be Pre-heated as soon as possible at 80~150℃ for 8~15 mins to evaporate. ( according to heat absorption of workpiece.)
6.5 Curing
The workpiece after pre-heating should be cured at 300-340℃ for 20-40 mins. ( according to heat absorption of workpiece.)
7. Attentions
Other chemicals such as any kinds of acid, alkali salt can not be mixed into coating, for these can activate Zn & Al plate to aging the coating.
Avoid irradiation of sunshine and ultraviolet ray for long time when operating, otherwise it will accelerate aging or polymerization of the coating .
It is very important to control the temperature of coating. If the temperature of coating changes when operating, it will effect the viscosity, then effec the coating quatity on workpiece. So the relations among temperature,viscosity and spinning process shoud be controlled well when coating.
The viscosity will be different if coating method is different. Choose low data if spray coating,and choose high data if dip spin coating.
8. Packing
| Pack A: | 16kg/ Metal Barrel | Pack B: | 24KG Plastic Barrel | Pack C: | 5.0kg metal barrel |
9. Quality guarantee period
Before compound 6 months at 20℃
After compound 40 days at 20℃ ( It can be recycled if adding fresh coating continuously. )
It should be stored under 20℃ if not in use.
