Dyeing of 100% Nylon fabric with Acid dye

Acid dyes are highly water soluble, and have better light fastness than basic dyes. The textile acid dyes are effective for protein fibers such as silk, wool, nylon and modified acrylics. They contain sulphonic acid groups, which are usually present as sodium sulphonate salts. These increase solubility in water, and give the dye molecules a negative charge. In an acidic solution, the -NH2 functionalities of the fibres are protonated to give a positive charge: -NH3+. This charge interacts with the negative dye charge, allowing the formation of ionic interactions. As well as this, Van-der-Waals bonds, dipolar bonds and hydrogen bonds are formed between dye and fibre.

Nature of Sample:?100% Nylon Woven?fabric.

Apparatus Required: Beakers, Glass Rod, Pipette, Measuring Cylinder, Digital Balance, Tri-pod Stand, Gas burner, Thermometer, Pot, pH Meter etc.

Process Sequence

Collection of 100% Nylon?sample > Dyeing with Acid dye at 100 deg C for 20 Minutes > ?After Treatment > Cold rinsing > Hot wash > Cold rinsing > Drying

Recipe:

Acid Dye: 1% o.w.f (Stock Solution - 1%) ,

Wetting Agent: 1 g/L (Stock Solution - 1%)

Acetic Acid: 0.8 g/L (Stock Solution - 1%)

Temperature: 100 deg C

Time: 20 minutes

pH:??4.5 - 5.5

Fabric Weight: 5gm

M:L =?1:30

?

Calculation:

Total Liquor required

Fabric Weight = 5gm

M: L = 1:30

Required amount of liquor = 5 X 30 =150mL

Acid?Dye: = (5?X1%) / (1%) = 5ml

Wetting Agent:?1g/L = (150X1g/L) / (1% X 1000) = 15ml

Acetic Acid:?0.8g/L= (150X?0.8 g/L) / (1% X1000) = 12ml

Initial Water required = Total liquor?– Chemicals

=150 - (15+12+5) = 150-32 mL = 118 mL

?Function of Chemicals:

Wetting Agent:?Wetting agent is substances that reduce the surface tension of water to allow it to spread drops onto a surface, increasing the spreading abilities of a liquid. Lowering the surface tension lowers the energy required to spread drops onto a film.

?Acid Dye:?The main substance to color the sample.

?Acetic Acid:?Acetic acid used for maintain pH 4.5-5.5. Because the Acid dye only works in acidic medium.

Comments:?The Nylon fabric turn orange color after dyed by Acid Dye.

Pre-cautions:

All chemicals measure are taken properly.

Temperature maintain properly.

Burner used very carefully.

Time maintain according to recipe.