Low temperature dyeing of wool fabric by acid dyeafter UV irradiation

PRESENTED BY: RANA ALI HAIDERREGISTRATION NO: 14-NTU-0140

Abstract The aim of the work was to improve wool’s dyeability

using acid dye through a simple pretreatment with ultraviolet (UV) irradiation.

Different radiation doses were investigated using a laboratory UV lamp

UV-treated fabrics were characterized in terms of morphological, chemical and physical properties by SEM

Finally the colour levelness of the dyeings obtainedon fabrics with and without irradiation was assessed.

Introduction In conventional process there involve a long time

treatment of wool at high tempratue this can damage the certain properties e.g. Chemical and Mechanical properties and also weakens the fiber

Such damage can be minimized by reducing the operation time or, better yet, by reducing the dyeing temperature.

Many pretreatments are done 4 this purpose These pretreatments were difficult to handle Finally pretreatment with UV increase wettability,

dye uptake and its fixation at low temperature

Experimental Work Sample were investigated in order to optimize

the process. The surface of fabrics was exposed to UV radiation by

1. Low Energy Mercury Lamps of irradiant 50 mW/cm2

2. SunWash with Irradiance of 900 mW/cm2 The UV treatment was carried out also on wet

samples, in order to reduce the yellowing Treated by passing through Conveyr Belts

Fabric Characterization To evidence a possible damage of wool

fibres caused byUV radiation, the surface morphology was examined by SEM

Following characteristics were seen 1. Wetability (Drop shape analysis

tensiometer)2. Bursting Strength3. Pilling (Marten Dale)

Dyeing

Dyeing is done by eliminating the use of Retardent

1) 1:30 liquor on the weight of Fabric2) 1% Dye on the Weight of Fabric3) PH maintained 4 by Acetic Acid Dyeing is done at different Tempratures e.g

70,80,90°C

Results and Discussion Surface Morphology of both the treated and

Untreated fabric was compared it comes to know that there is no difference between

surface Morohology

For UV treated Fabric Water contact angle decrease

130° 110°

Wetability increase The dyeability, at each investigated

temperature, the radiated samples showed better results in terms of kinetics and final bath exhaustion

Finally we have to check Color Levelness( i.e uniformity of color shade at different place) at both UV Treated and Untreated fabric

Finally, after drying, colour measurements byDatacolour were performed on each dyed fabrics

Colour differences ΔE for each place with respect the mean values were obtained.

Conclusion They suggested that such treatment leads to the

increase in the amorphous amount of the exposed fibres

Finally it was suggested that specimen treated with Low Power Mercury Lamp or High Power Mercury lamp can be Dyed at temperature 20°C lower temperature than conventional dyeing, with a fast kinetics

showed better colour uniformity than the untreated fabrics

Moreover some additional properties are added to Specimen