Sulphur Black v/s Reactive Black(Woraphot Wattanaphan)

Light FastnessSulphur black rates 5 on the grey scale after 40 hours xenon. Reactive black rates only 3.0.

Perspiration Light FastnessTest is based on duplicating exposure to light combined with perspiration. Sulphur black rates 5.0 after 20 hrs. Reactive black shows break at 2 hrs with a rating of 2.5 after 20 hrs.

Dyeing CyclesSulphur black can be dyed in 3.5 – 4 hours vs typical reactive time of 6 – 7 hours. Sulphur cycles require much less salt (20 – 30 g/l) vs reactive where 100 – 120 g/l is needed.

Wash FastnessSulphur black gives practicaly no stain in the AATCC 2a wash test. As a result of this, sulphur black can be used in “color blocking” with pastel shades. Reactive black would require a fix to obtain the best results.

Crock fastnessWet crock fastness for shades of equal depth is about equal. Most reactive black shades are much lighter in depth, giving slightly better crock fastness.

Reworks and overdyesSulphur blacks are easily reworked using the original process without stripping. Reactive blacks require a caustic/ hydro strip and full formula add. Sulphur black can be used to overdye many reactive colors without having to strip first.

TenderingTendering is minimized by controlling the fabric pH. The fabric must have an alkaline pH from the dye machine prior to finishing.After fi nishing the pH must also be above 8.0.

Lot Dyehouse pH Finished pH Original strength Aged strength % loss

1 9.5 8 89 80 10%

2 9.8 7.4 90 81 10%

3 9.3 8 87 85 2%

4 9.8 8.1 97 94 3%

5 8.3 102 87 14%

6 8.4 104 95 9%

7 8.5 107 96 10%

8 9 107 93 13%

9 7.4 106 87 18%

SummaryGood fastness in repetitive domestic washing.Excellent light and perspiration light fastness.Minimal water use and low salt use.Dyebath re-cycling is possible.A much deeper, richer shade of black.Easier re-processing and over-dyeing possibilities.Shorter cycles.