Preface

Nearly all textile materials are colored after fabrication and before final finishing. The coloration of fibers and fabrics through dyeing is an integral part of textile manufacturing. This book discusses in detail several emerging topics on textile dyeing.

The pretreatment of textiles prior to dyeing is addressed by several authors. Menezes and Choudhari present chemical alternatives to traditional pretreatment, while Tavcer discusses enzyme pretreatment procedures. Bendak and Raslan review pretreatment methods of protein and synthetic fibers, and Bhatti et al. introduce the concept of radiation induced pretreatment. Control of the dyeing process is discussed by Günay and enhancing the dyeability of fibers is reviewed by Gashti et al. Details for dyeing specific fiber types are given by Gupta et al (polypropylene), Suesat and Suwanruji (polylactic acid), and Giménez-Martín et al (acrylic). Individual dyestuff classes are addressed by Koh (disperse dyes), Rippon et al (vat dyes). The use of cyclodextrins as dye leveling agents is reviewed by Voncina while Durasevic et al. suggest that photochromic dyes can function as useful sensors. The interaction of plasma with textile material prior to dyeing is well represented with chapters by Durasevic et al, Souto et al, Deshmukh and Bhat, and Mokbul and Dirk.

"Textile Dyeing" will serve as an excellent addition to the libraries of both the novice and expert.

> **Prof. Peter J. Hauser**  Director of Graduate Programs and Associate Department Head Textile Engineering, Chemistry & Science Department North Carolina State University USA

**1** 

*Pakistan* 

**Effect of Radiation on Textile Dyeing** 

*1Department of Chemistry & Biochemistry, University of Agriculture, Faisalabad, 2Department of Applied Chemistry,*

*3Haris Dyes and Chemicals Faisalabad,* 

*G.C.University, Faisalabad,* 

Ijaz Ahmad Bhatti1, Shahid Adeel2 and Muhammad Abbas3

Love for colours is a natural instinct and every individual has his own choice and liking for colour. The icy appearance of Hamaliyan ranges or lush green forests or fields of agriculture or trees laden with colorful fruits or butterflies moving from flower to flower presents the beauty of nature, generation after generations are being attracted. The choice of beautiful

Colour is visual perceptual property corresponding in humans to the categories called red, yellow, blue and others. It is a sensation that arises from the activity of retina of the eye and its attached nervous mechanism, and results in a specific response to the radiate energy of certain wavelength and intensity. Thus it is a quality of an object with respect to light (Mizzarini *et al.*, 2002).Colorants may be either pigment or a dye which are characterized by their ability to absorb or emit light in the visible range 400-700nm.They may be organic or

Dyes are the coloured substances which are capable of imparting their colours to the matrix which may be fiber, paper or any object. They must have fixing tendency on a fabric that is impregnated with their solution and the coloured fixed dyes must be fast to light as well as resistant to action of water, dilute acids, alkalies, various organic solvents used in dry cleaning, soap solutions, detergent, etc ( Shukla, 1992 ) . A pigment generally is a substance which is insoluble in the medium in contrast to dye in which it is applied and has to be attached to a substrate by additional compounds e.g. polymer in paints and plastics (Taylor

A compound looks coloured because it has absorbed certain electromagnetic radiation from the visible region. The moieties, present in colouring substance, responsible for the absorption of electromagnetic radiation and reflect in the visible region are called chromophores (Younas, 2006).Ultraviolet radiation constitutes to 5% of the total incident sunlight on earth surface (visible light 50% and IR radiation 45%). Even though, its proportion is quite less, it has the highest quantum energy compared to other radiations. Light is electromagnetic in nature. Within the electromagnetic spectrum, human eye captures visible light in the range between about 380 nm and 700 nm (Mizzarini *et al.*, 2002). Dyes absorb electromagnetic radiation of varying wavelength in the visible range of

fascinating colours reflects the aesthetic sense of humans that varies.

inorganic depending upon their structure and method of production.

**1. Introduction** 

and Nonfiction, 2006)
