Vat Green 8(VAT khaki 2G) generally looks like black powder, insoluble in water, alcohol and organic solvents, dark brown in concentrated sulfuric acid, and olive-green precipitation after dilution.
TRADE NAME:VAT khaki 2G,Vat olive green 5G,Vat Khaki 2G
Dyeing depth g/L | 20 |
Dyeing method | IN |
Leuco color | Brown |
Leveling property | ▲▲ |
Dead cotton | ▲ |
Light (Xenon test 1/12) | 5 |
Light (Xenon test 1/1) | 6-7 |
Light (Xenon test 2/1) | 7 |
Sun fastness | Soaping(95℃) | Perspiration | Rubbing | Ironing | Bleach resistant | Mercerizing | |||||||
Standard Depth | 1/12 Depth | Sample change | White stained | Sample change | White stained | Dry | Wet | immediately | After 4h | Chlorine bleaching | Oxygen bleaching | Sample change | White stained |
7~8 | 6 | 5 | 5 | 4 | 5 | 4 | 2 | 4 | 4~5 | 4 | 4~5 | 4~5 | 5 |
Vat Green 8 Mainly used for dyeing cotton fiber. Applies to vat olive green b or brilliant green FPB fight with grass green, khaki, but also suitable for knitwear, yarn, cotton and polyester / cotton blended fabric dyeing. Printing less effective.
1.Reduction for cotton vat khaki 2g jig dyeing or impregnation, the most appropriate to use a method, the second method is suitable for b, also can use a special method (a method than usual increase in the amount of caustic soda 30% ~ 40%). Using dry cylinder reduction, a commonly used method, dry cylinder reduction time 10 ~ 15 min, temperature 60 ℃, dry cylinder stable time for 30 min.
2.Reduction of cotton fiber of vat khaki 2 g leuco high affinity, poor levelness, dyeing curve as shown in figure 4, 5-31. The dead cotton covering power, is the main dye with grass green. Dyeing, should strictly control the temperature, otherwise the colored light change is bigger, there will be a green or pale brown color. In addition to the available water to wash, such as air oxidation after dyeing, also can use dichromate oxidation, the colored light. Such as pickled before soaping, should be washed after acid and then to soaping, ensure its full hair color, and color normal (green). In addition to the jig dyeing or disseminated, more suspension for cotton, polyester-cotton blended fabric pad dyeing.
3.Reduced Vat Green 8 has a poor printing effect due to its low fixation force. If it is used for printing, better printing effect can be obtained by mixing printing pulp with strong alkali. It is not suitable for discharge proof printing.
4.Reduction Vat Green 8 dyeing viscose fiber, the effect is poorer, when the low temperature dyeing, color is very shallow, above 60 ℃ dyeing, color is deep, but the color brown. Stick cotton blended fabric dyeing, viscose fiber groups of color is light than cotton.
5.After reduction Vat Green 8 printing and dyeing fabric was treated with urea formaldehyde or cyanal resin, the color became slightly lighter.
The reduced Vat Green 8 should be stored in a dry, cool and ventilated place to prevent moisture.
Typical application uses the vatting (reduction) method: disperse the dye, reduce it to the soluble leuco form with an alkaline reducing bath, apply to the substrate (pad or exhaust), then re-oxidize to regenerate the insoluble dye within the fibre. For continuous or padding lines, the sequence is: impregnation with reduced dye liquor → squeeze → oxidation/wash-off → final rinsing and finishing. Small-scale lab sample trials are recommended to dial in exact conditions.
Common reducing systems include sodium hydrosulfite (sodium dithionite) with an alkali such as sodium hydroxide; alternatively, commercial one-bath vatting auxiliaries and enzymatic or mercerization-compatible systems may be used. Choose auxiliaries that improve leveling and prevent deposits; compatibility tests with your finishing chemicals are recommended.
When correctly vat-applied and oxidized, Vat Green 8 delivers very high wash and wet fastness, strong resistance to crocking, and good light fastness compared with many direct or reactive greens. Actual ISO/AATCC ratings depend on substrate and process—report your lab test results for specification sheets.
After complete oxidation and washing, standard softening and leveling finishes can be applied. Anti-migration or oil-repellent finishes should be trialed to ensure they do not affect shade or fastness. For garment washing resistance, consider a robust fixation plus a final neutralizing rinse.
Shade matching requires control of liquor ratio, reduction/oxidation kinetics and auxiliaries. Provide lab samples and target L*a*b* values to the supplier; maintain consistent process recipes and perform regular lab spectrophotometric checks during production to ensure batch reproducibility.
