Vat Blue VB has a dark blue powder. It is insoluble in water, and the leuco body formed by the dye in the alkaline powder solution is blue.
It is a domestic compound dye blended, mainly to solve the problem of flamala blue red, instead of the blue salt VB dye. The blending ratio varies according to the intensity of the dye itself and the requirements for the blue color. under:
TRADE NAME:Vat Dark Blue VB
Dyeing depth g/L | 30 |
Dyeing method | IN |
Leuco color | Blue |
Leveling property | ▲▲ |
Dead cotton | △ |
Light (Xenon test 1/12) | 6 |
Light (Xenon test 1/1) | 6-7 |
Light (Xenon test 2/1) | 7-8 |
Dyeing method | Dyeing Temperature(℃) | Reduction method | Reduction temperature (℃) | Leveling property | Other properties |
Most suitable for method A, also aviable for method B | 50~60 | Dyr cylinder, Full bath | 50~60 | Normal | The dye is sensitive to high temperature |
Light Fastness | soaping(95℃) | Perspiration | Rubbing | Ironing | Bleaching resistant | Mercerized | |||||||
Standard depth | 1/12 depth | Orginal color changed | White fabric stained | Orginal color changed | White fabric stained | Dry | Wet | Immediately | 4h after | Chlorine bleaching | Oxygen Bleaching | Orginal color changed | White fabric stained |
7~8 | — | 3~4 | 4~5 | 3~4 | 4~5 | 4 | 2~3 | — | 3~4 | 2~3 | — | 3 | — |
Vat Blue VB Mainly used for silk dyeing, levelness and affinity are good. Used to stick/cotton blended fabric cold dyeing, uniform color. Also can be used for polyester/cotton two bath dyeing. Can also be processed into organic pigment.
1.For cotton product dyeing or dip dyeing, it is suitable to use the method of A or B. It can be reduced by whole bath or reduced by dry cylinder, the reduction temperature is 60 °C, and the dyeing temperature is 50~60 °C.
2. leuco body has higher affinity to cotton fiber, uniform dyeing and faster dyeing rate. In order to avoid uneven dyeing, the temperature should not be too high when the initial dyeing, and add appropriate amount of bone glue as retarder. In addition, the reduced dark blue BO in the dye is sensitive to heat, so the temperature should be avoided when drying. It is mainly used for the suspension padding of cotton fabrics and polyester-cotton blended fabrics.
3.Vat blue VB (Vat dark blue VB) is generally not used for printing.
4. It can be used for the dyeing of cotton blend fabrics, as well as for the dyeing of viscose fibers.
1. Sometimes due to the lack of purity of the Vat blue RSN, the dark blue BO has poor heat resistance, unstable color shade or “wind print.” After the “wind print” is produced, 1 g/L of the insurance powder can be padded for repair.
2. When used for dyeing cotton yarns, it should be avoided on color fabrics that require chlorine bleaching or mercerizing to prevent color change.
3.It should be stored in a dry, ventilated place to avoid moisture.
Yes. Vat Blue VB performs well in both traditional batch vatting and pad-steam processes. For pad-steam, ensure reductive vatting (sodium dithionite or thiourea dioxide) and strict control of pH and oxidation steps to secure even fixation and minimal bleeding.
Common reducing agents are sodium dithionite (hydrose) and thiourea dioxide. Typical working ranges are around 0.5–3.0% (w/w on fabric) for sodium dithionite depending on shade depth and liquor ratio; always run lab trials to optimize for your liquor ratio and fabric construction.
Vat Blue VB is optimized for cellulose fibres — cotton, viscose, lyocell and their blends. It gives best penetration on open-weave and knitted structures; tightly compacted or heavily resin-finished fabrics may need ajusted wetting and longer padding times for uniform uptake.
After reduction and application, apply controlled oxidation (air or mild peroxide) until the dye is fully converted to the insoluble form; follow with sequential cold and hot washes, using non-ionic wetting agents and a mild alkali neutralizer if necessary. Proper oxidation and rinsing strongly reduce crocking and residual soluble dye.
Store in a cool, dry place in tightly sealed containers away from strong reducing agents and moisture. Use appropriate PPE (gloves, goggles) when handling powders; avoid inhalation and minimize dust. Follow your local SDS for disposal and spill procedures.
Vat Blue VB mixes predictably with other vat blues and selected vat greens/reds for shade modification. Because vat dyes fix as insoluble leuco forms, run small-scale trials and full washfastness checks after blending — tinctorial strength and final fastness are influenced by reduction/oxidation completeness.
We recommend small-bath trials at your production liquor ratio with stepwise variation of: reducing agent dose (±0.5% increments), pH (alkali level), temperature and oxidation time. Test washfastness (ISO/AATCC), lightfastness, and crocking before full-scale production.
