Reference Document on Best Available Techniques for the

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Textiles Industry

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JRC-IPTS Instituto de Prospectiva Tecnológica (IPTS)

2003

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EXECUTIVE SUMMARYI

PREFACEXXI

SCOPE .XXXVII

1 GENERAL INFORMATION. 1

1.1 Wool scouring sector .3

1.1.1 Sector organisation3

1.1.2 Production and economics.3

1.2 Textile finishing sector (excluding floor covering) .5

1.2.1 Sector organisation5

1.2.2 Production and economics.6

1.3 Carpet .7

1.3.1 Sector organisation7

1.3.2 Production and economics.9

1.4 Main environmental issues 11

2 APPLIED PROCESSES AND TECHNIQUES 15

2.1 Raw materials 16

2.1.1 Fibres16

2.1.2 Chemicals & auxiliaries 21

2.1.3 Materials handling and storage22

2.2 Fibre manufacturing: chemical (man-made) fibres22

2.3 Fibre preparation: natural fibres 24

2.3.1 Wool.24

2.3.2 Cotton and flax34

2.3.3 Silk .34

2.4 Yarn manufacturing34

2.4.1 The wool spinning process34

2.4.2 The cotton spinning process34

2.4.3 Environmental issues.35

2.5 Cloth production 35

2.5.1 Woven textiles.36

2.5.2 Knitted textiles 37

2.5.3 Textile floor-coverings37

2.5.4 Non-woven textiles .40

2.6 Pretreatment41

2.6.1 Pretreatment of cotton & cellulose fibres41

2.6.2 Wool preparation before colouring .49

2.6.3 Pretreatment of silk .53

2.6.4 Pretreatment of synthetic material.56

2.7 Dyeing 57

2.7.1 General principles of dyeing .57

2.7.2 Dyeing processes.58

2.7.3 Cellulose fibres dyeing61

2.7.4 Wool dyeing 67

2.7.5 Silk dyeing 69

2.7.6 Synthetic fibres dyeing69

2.7.7 Fibre blends dyeing .73

2.7.8 Environmental issues.77

2.8 Printing .86

2.8.1 Printing processes86

2.8.2 Printing technology .90

2.8.3 Environmental issues.96

2.9 Finishing (functional finishing) .99

2.9.1 Finishing processes .99

2.9.2 Chemical finishing treatments.100

2.9.3 Environmental issues.103

2.10 Coating and laminating105

2.10.1 Coating and laminating processes. 105

2.10.2 Environmental issues 106

2.11 Carpet back-coating. 107

2.12 Washing . 113

2.12.1 Washing with water 113

2.12.2 Dry cleaning 113

2.13 Drying 115

2.13.1 Loose fibre drying. 116

2.13.2 Hanks drying. 116

2.13.3 Yarn packages drying . 117

2.13.4 Fabric drying. 117

2.14 Textiles industry categories. 119

2.14.1 Wool Scouring Mills. 120

2.14.2 Mills finishing yarn and/or floc 120

2.14.3 Mills finishing knitted fabric 121

2.14.4 Mills finishing woven fabric. 123

2.14.5 The Carpet industry 126

3 EMISSION AND CONSUMPTION LEVELS137

3.1 Introduction 137

3.2 Wool scouring mills 137

3.2.1 Cleaning and washing with water . 137

3.2.2 Cleaning and washing with solvent 152

3.3 Textile finishing industry 153

3.3.1 Mills finishing yarn and/or floc 153

3.3.2 Mills finishing knitted fabric 162

3.3.3 Mills finishing woven fabric. 176

3.4 Carpet industry. 207

3.4.1 Wool and wool-blend carpet yarn dyehouses . 207

3.4.2 Integrated carpet manufacturing companies . 217

3.5 General issues concerning odour nuisances in the textile industry . 223

3.6 General issues concerning solid & liquid wastes generated in the textile industry . 224

4 TECHNIQUES TO CONSIDER IN THE DETERMINATION OF BAT227

4.1 General good management practices. 227

4.1.1 Management and good housekeeping. 227

4.1.2 Input/output streams evaluation/inventory 231

4.1.3 Automated preparation and dispensing of chemicals 236

4.1.4 Optimising water consumption in textile operations 239

4.1.5 Insulation of High Temperature (HT) machines. 242

4.2 Quality management of incoming fibre. 243

4.2.1 Man-made fibre preparation agents with improved environmental performance . 243

4.2.2 Mineral oils substitution in wool spinning lubricants . 246

4.2.3 Mineral oils substitution in knitted fabric manufacturing. 247

4.2.4 Selection of sizing agents with improved environmental performance 249

4.2.5 Minimising sizing agent add-on by pre-wetting the warp yarns. 253

4.2.6 Use of techniques that allow reduced load of sizing agents on the fibre (compact spinning) .

254

4.2.7 Minimising residues of organochlorine ectoparasiticides in the raw material by substitution. 256

4.2.8 Minimising residues of organophosphate and synthetic pyrethroid ectoparasiticides in the raw

material by substitution 258

4.3 Selection/ substitution of chemicals used 260

4.3.1 Selection of textile dyes and auxiliaries according to their waste water relevance. 260

4.3.2 Emission factor concept (emissions to air) . 262

4.3.3 Substitution for alkylphenol ethoxylates (and other hazardous surfactants). 264

4.3.4 Selection of biodegradable/bioeliminable complexing agents in pretreatment and dyeing

processes 267

4.3.5 Selection of antifoaming agents with improved environmental performance. 270

4.4 Wool scouring . 272

4.4.1 Use of integrated dirt removal/grease recovery loops. 272

4.4.2 Use of integrated dirt removal/grease recovery loops combined with evaporation of the

effluent and incineration of the sludge 275

4.4.3 Minimising energy consumption in wool scouring installations.280

4.4.4 Wool scouring with organic solvent282

4.5 Pretreatment283

4.5.1 Recovery of sizing agents by ultrafiltration 283

4.5.2 Application of the oxidative route for efficient, universal size removal .288

4.5.3 One-step desizing, scouring and bleaching of cotton fabric290

4.5.4 Enzymatic scouring.291

4.5.5 Substitution for sodium hypochlorite and chlorine-containing compounds in bleaching

operations 293

4.5.6 Minimising consumption of complexing agents in hydrogen peroxide bleaching 295

4.5.7 Recovery of alkali from mercerising.298

4.5.8 Optimisation of cotton warp yarn pretreatment.300

4.6 Dyeing 302

4.6.1 Exhaust dyeing of polyester and polyester blends with carrier-free dyeing techniques or

with use of environmentally optimised carriers 302

4.6.2 Use of non-carrier dyeable PES fibres 304

4.6.3 Dispersing agents with higher bioeliminability in dye formulations.306

4.6.4 One-step continuous vat dyeing in pastel to pale shades.308

4.6.5 Aftertreatment in PES dyeing309

4.6.6 Dyeing with sulphur dyes313

4.6.7 Minimisation of dye liquor losses in pad dyeing techniques.315

4.6.8 Enzymatic after-soaping in reactive dyeing 317

4.6.9 Silicate-free fixation method for cold pad batch dyeing .318

4.6.10 Exhaust dyeing of cellulosic fibres with high-fixation polyfunctional reactive dyestuffs 320

4.6.11 Exhaust dyeing with low-salt reactive dyes 323

4.6.12 Omitting the use of detergents in afterwashing of cotton dyed with reactive dyes .324

4.6.13 Alternative process for continuous (and semicontinuous) dyeing of cellulosic fabric with

reactive dyes326

4.6.14 pH-controlled dyeing techniques.329