There are some common problems in India maximum textile dyeing house for example poor wet rubbing fastness in dark shade (Dark maroon burgandany, dark red etc).

In exhaust reactive dyeing method (60 degree Celsius dyeing temperature) following variable factor has to be checked: -

1)       Material/liquor ratio.

2)       Temperature.

3)       Electrolyte.

4)       Auxiliaries.

5)       Water Hardness and Ph.

6)       Proper selection of dye.

7)       Substrate

We will directly approach to the root cause of the problem.

Case Study I

Material=2/4 count (cotton Yarn)

Material/ Liquor ratio =1; 20

Machine = Cabinet dyeing machine

Shade:-Dark maroon

Dyeing Recipe:

Reactive Red SYG (local) =4.0% owf

Reactive Yellow RD (Local) =1.4% owf

Reactive Navy Blue SGL (Local) =0.2% owf

Common salt=80 gpl, Soda ash=5 gpl+ caustic soda=1 gpl

Dyeing process: -dyesaltsoda exhaust dyeing process (60 degree temperature dye).

Wet Rubbing fastness is coming (normal) =2 (ISO; 105-X12)

After investigation of above problem following two factors was observed which was creating problem (bottom mentioned)

Water hardness: Water hardness was observed 420 ppm. In dyeing bath after local sequestering agent (1 Gram /liter) addition also poor wet rubbing fastness was observed.

Selection of Dye

From Filter paper test (Figure I) it was clearly observed that dye precipitation was there before draining of dye liquor in lab trail.