Physico-chemical Aspects of Textile Coloration

Stephen M. Burkinshaw

• Publisher: Wiley
• Year: 2015
• ISBN:
  9781118725580
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Physical & Theoretical Chemistry

The production of textile materials comprises a very large and complex global industry that utilises a diverse range of fibre types and creates a variety of textile products. As the great majority of such products are coloured, predominantly using aqueous dyeing processes, the coloration of textiles is a large-scale global business in which complex procedures are used to apply different types of dye to the various types of textile material. The development of such dyeing processes is the result of substantial research activity, undertaken over many decades, into the physico-chemical aspects of dye adsorption and the establishment of 'dyeing theory', which seeks to describe the mechanism by which dyes interact with textile fibres. Physico-Chemical Aspects of Textile Coloration provides a comprehensive treatment of the physical chemistry involved in the dyeing of the major types of natural, man-made and synthetic fibres with the principal types of dye. The book covers:

• fundamental aspects of the physical and chemical structure of both fibres and dyes, together with the structure and properties of water, in relation to dyeing;
• dyeing as an area of study as well as the terminology employed in dyeing technology and science;
• contemporary views of intermolecular forces and the nature of the interactions that can occur between dyes and fibres at a molecular level;
• fundamental principles involved in dyeing theory, as represented by the thermodynamics and kinetics of dye sorption;
• detailed accounts of the mechanism of dyeing that applies to cotton (and other cellulosic fibres), polyester, polyamide, wool, polyacrylonitrile and silk fibres;
• non-aqueous dyeing, as represented by the use of air, organic solvents and supercritical CO 2 fluid as alternatives to water as application medium.

The up-to-date text is supported by a large number of tables, figures and illustrations as well as footnotes and widespread use of references to published work. The book is essential reading for students, teachers, researchers and professionals involved in textile coloration.

1
Fundamental Aspects of Textile Fibres

1.1 Textiles

The modern definition of the word textile, namely (n.) a type of cloth or woven fabric [1], reflects the early seventeenth century origins of the word as relating to a woven fabric and the process of weaving. Nowadays, the word has more extensive meanings and associations, such as textile-filament, -fibre, -yarn and -fabric, and relates to the preparation of knitted, tufted and non-woven fabrics, as well as woven fabrics. In a similar vein, the modern definition of the word fibre, as a thread or filament from which a vegetable tissue, mineral substance, or textile is formed [1], also is the result of considerable linguistic evolution since its origins in the early fifteenth century [2] to describe lobes of the liver and entrails [1].

Essentially, textile materials can be considered as principally cohesive, fibrous assemblies in which individual fibres are assembled via friction. A wide range of textiles is commercially available, the different types of such products varying, markedly, in terms of both the geometric arrangement of the fibrous materials (e.g. woven fabric, yarn and non-woven) and the derivation, structure, physical characteristics and chemical properties of the component textile fibres. Since, in its broadest sense, the theory of the dyeing of textiles concerns the nature of the interactions that operate between such fibrous assemblies and dyes, these interactions can be considered in terms of three aspects:

1. the gross structural arrangement of the fibrous assembly (e.g. yarn, woven fabric and garment);
2. the constituents of the fibrous assembly (i.e. fibre, filament, etc.);
3. the composite macromolecules.

Of the large amount of research that has been carried out on dyeing theory, the vast majority has tended to focus less on the physical form of a textile material (i.e. fabric, garment, yarn, etc.) and more on the constituents of the fibrous assembly (fibres, filaments, etc.), with especial attention being placed on interactions that occur at a macromolecular level. Whilst it seems appropriate to consider these three particular aspects of textile physics and chemistry, with emphasis on the constituents of the fibrous assemblies (i.e. textile fibres) from a macromolecular perspective, anything other than an outline of this large and inordinately complex area is neither possible nor required here.

In the context of the gross structural arrangement of fibrous assemblies, textile materials are available in a variety of different physical forms, including, for example¹:

• yarn
  • staple spun (comprise staple fibres); e.g. ring spun, air-jet spun, rotor spun;
  • filament (comprise one or more mono- or multi-filament(s) with/without twist); e.g. untextured (aka flat), textured, interlaced, tape, stretch, bulky;
  • composite (comprise staple and filament components in at least two strands, one core and a wrap strand); e.g. filament core, staple core;
  • fancy (comprise deliberate irregularities to achieve effects); e.g. chenille, boucle, fleck, etc.;
  • specialist (hybrid, triaxial woven, compound);
• cordage;
• flock;
• woven fabric
  • plain-weave, twill fabrics, satin fabrics, complex (e.g. leno, jacquard, etc.);
• knitted fabric
  • weft-knitted: single knits (e.g. jersey, purl, etc.); double knits (e.g. interlock);
  • warp-knitted: tricot, raschel, net, lace;
• non-woven
  • dry-laid, air-laid, wet-laid, polymer-laid (and associated bonding processes; e.g. hydroentanglement, needle punching, thermal, chemical, stitching).

Textiles can be dyed at various stages of their manufacture (Table 1.1) depending on the particular manufacturing process used, cost, end use requirements, fastness, etc. Of these various physical forms, yarn and fabric are the two most commonly encountered forms in dyeing.

Table 1.1 Stages of textile processing at which dyeing can be undertaken.

fibre	mass coloration^a	gel dyeing^b	loose stock^c	yarn	piece	garment
Cotton	−	−	+	+	+	+
CA/CTA^d	+	−	−	+	+	+
CV^d	+	−	+	+	+	+
PA^d	+	−	+	+	+	+
PAN^d	+	+	+	+	+	+
PES^d	+	−	+	+	+	+
Wool	−	−	+	+	+	+

^a a method of colouring man-made fibres by incorporation of colourants in spinning composition before extrusion into filaments [3].

^b a continuous tow-dyeing method in which soluble dyes are applied to wet-spun fibres (e.g. acylic or modacrylic fibres) in the gel state (i.e. after fibre extrusion and coagulation, but before drawing and drying) [3].

^c fibres in the randomised state.

^d please refer to Figure 1.7 for definitions of the various textile fibre generic names.

1.1.1 Yarn

Yarn [4–10] is defined as [11] a product of substantial length and relatively small cross-section, of fibres and/or filaments with or without twist and fabric as a manufactured assembly of fibres and/or yarns that has substantial area in relation to its thickness and sufficient cohesion to give the assembly useful mechanical strength.² Yarn is essentially a transitional product insofar as it is mostly converted into more significant textile products such as woven fabric (by interweaving), knitted fabric (by interlooping) or rope and braid (by intertwisting). Some 90% of fibres are first spun into yarn [5] which is employed in the form of long, fine fibres that consist of either a twisted assembly of staple fibres (fibre of finite, usually short length) or parallel continuous filaments (fibres of infinite length). As such, two types of yarn are produced, namely spun yarn and filament yarn.

It seems appropriate at this point to co...

Table of contents

• Cover
• Title Page
• Table of Contents
• Society of Dyers and Colourists
• Preface
• 1 Fundamental Aspects of Textile Fibres
• 2 Dyes
• 3 The Role of Water in Aqueous Dyeing
• 4 Fundamentals of Dyeing
• 5 Dye–Fibre Interactions
• 6 Dyeing Theory
• 7 Cellulosic Fibres
• 8 Polyester Fibres
• 9 Polyamide Fibres
• 10 Wool Fibres
• 11 Acrylic (Polyacrylonitrile) Fibres
• 12 Silk Fibres
• 13 Non-aqueous Dyeing
• Colorants Index
• Subject Index
• End User License Agreement