«EUROPEAN COMMISSION Integrated Pollution Prevention and Control (IPPC) Reference Document on Best Available Techniques for the Textiles Industry July 2003 ...»
Figure 4.18: Basic chemicals consumption per 10 million metres with pad-dry-pad-steam, pad-batch, paddry-thermofix and the reference technique
Figure 4.19: Fabric temperature and humidity during the dyeing process using the referenced technique
Figure 4.20: Structure of a typical bifunctional reactive dyestuff for wool of the bromo-acrylamide type
Figure 4.21: Dyeing curve for the application of reactive dyestuffs for wool exhaust dyeing.
................337 Figure 4.22: Dyeing of loose wool fibre and combed tops: comparison between the dyeing curve for the conventional process (whole curve) and the optimised process (Lanaset TOP process) (dotted part of the curve)
Figure 4.23: Supraflor Carpet Winch
Figure 4.24: Illustration of an airflow dyeing machine with indication of air circulation and injection of the bath
Figure 4.25: Illustration of the rinsing step in an airflow dyeing machine with indication of the open valve to achieve continuous rinsing
Textiles Industry xxxv Figure 4.26: Representation of the single-rope dyeing machine
Figure 4.27: Recovery of printing paste from the paste supply system by back-pumping an inserted ball
Figure 4.28: Chemical structure of cross-linking agents
Figure 4.29: Process Map for Mothproofing Dry-Spun Production
Figure 4.30: Process map for mothproofing stock dyed – yarn scoured production
Figure 4.31: Process map for mothproofing yarn dyed production
Figure 4.32: General layout of a conventional solvent scouring installation
Figure 4.33: General layout of a modern solvent scouring installation
Figure 4.34: Plant 1 – combined treatment of textile effluent and municipal waste water
Figure 4.35: Daily average COD concentration measured on the final effluent from Plant 1 in the year 2000
Figure 4.36: Plant 2 – combined treatment of textile effluent and municipal waste water
Figure 4.37: Daily average COD load measured on the final effluent from Plant 2 in 1999
Figure 4.38: Plant 3 – combined treatment of textile effluent and municipal waste water
Figure 4.39: Plant 4 – combined treatment of textile effluent and municipal waste water
Figure 4.40: Plant 5 –treatment of waste water from one textile finishing mill with 5 % water recycling
Figure 4.41: Plant 6 –treatment of waste water from one textile finishing mill
Figure 4.42: On-site treatment of mixed textile waste water with partial recycling of the treated effluent
Figure 4.43: Thermal treatment of excess sludge from the activated sludge treatment and sludge from flotation
Figure 4.44: Treatment of selected segregated waste water streams using a series of membrane techniques (ultrafiltration, nanofiltration and reverse osmosis) – the cut-offs are expressed in Dalton (D)
Figure 4.45: Layout of a plant for treatment and recycling of waste water from pigment printing paste preparation kitchen (water from scrubbers is treated in the same plant)
Figure 4.46: Scheme of the reactor for treatment by catalytic oxidation with O2/H2O2 of some segregated highly concentrated streams; on the left, illustration of the reactor at Schoeller AG, CHSevelen in operation since 1996
Figure 4.47: Capital cost of recent composting plant start-ups in UK.
(Source: The Composting Association, UK)
Figure 9.1: Examples of acid dyes
Figure 9.2: Examples of typical basic dyes
Figure 9.3: Examples of typical direct dyes
Figure 9.4: Examples of molecular structures typical of 1.
1 metal-complex dyes
Figure 9.5: Molecular structure typical of 1.
2 metal-complex dyes
Figure 9.6: Representation of possible ionic and coordination bonds between wool and chrome dyes.
.. 521 Figure 9.7: Examples of typical coupling components for naphthol dyes
Figure 9.8: Examples of typical developing agents (fast colour base) for naphthol dyes
Figure 9.9: Examples of typical fast colour salts
Figure 9.10: Reactive Black 5
Figure 9.11: Examples of typical vat dyes
Figure 10.1: Schematic layout of a conical pan loose fibre dyeing machine
Figure 10.2: Schematic diagram of a Hussong type hank dying machine
Figure 10.3: Schematic layout of a package dyeing machine
Figure 10.4: Schematic representation of a winch beck dyeing machine
Figure 10.5: Schematic representation of a jet dyeing machine
Figure 10.6: Schematic representation of an overflow dyeing machine
Figure 10.7: Schematic representation of jet dyeing machine
Figure 10.8: Example of continuous process for knitted fabric in rope form
Figure 10.9: Schematic representation of a beam dyeing machine
Figure 10.10: Schematic representation of a jigger
Figure 10.11: Foulard types
Figure 10.12: Illustration of some of the most important dye/finish applicators
Figure 10.13: Schematic layout of a pad-batch plant
Figure 10.14: Schematic representation of a pad-steam plant (wet steam) for dyeing with vat dyes.
SCOPE This document covers the industrial activities specified in Section 6.2 of Annex 1 of Directive 96/61/EC, namely:
"Plants for the pretreatment (operations such as washing, bleaching, mercerisation) or dyeing of fibres or textiles where the treatment capacity exceeds 10 tonnes per day".
Particular attention is given to the following processes:
· fibre preparation · pretreatment · dyeing · printing · finishing.
Upstream processes which may have a significant influence on the environmental impact of the subsequent wet processing activities are also briefly described.
The backing of carpets is included in this document because it is an intrinsic part of carpet manufacturing and has the potential to pollute the environment.
All main textile fibre types, namely natural fibres, man-made fibres derived from natural polymers such as viscose and cellulose acetate as well as man-made fibres derived from synthetic polymers are described, including their blends.
1 GENERAL INFORMATIONThe textile industry is one of the longest and most complicated industrial chains in manufacturing industry. It is a fragmented and heterogeneous sector dominated by a majority of Small and Medium Enterprises, with a demand largely driven by three main end-uses: clothing, home furnishing and industrial use.
The importance of the textile (and clothing) industry in the European economy is shown in Table 1.1. The figures in the table cover only a part of the total number of manufacturing companies in 2000 (i.e. they only cover companies with more than 20 employees).
This part of the industry represented:
- 3.4 % of EU manufacturing
- 3.8 % of the added valued and
- 6.9 % of industrial employment.
Table 1.1: Share of the EU-15 textile-clothing industry in the manufacturing industry (only companies with 20 employees or more) In reality, in 2000 the EU textile and clothing industry actually achieved a turnover of 198 billion euros, involving 114000 companies, who employed about 2.
2 million people.
The textile industry’s activities are distributed right across Europe, but mainly concentrated in only a few EU states. Italy is the leading European producer, far ahead of Germany, the UK, France and Spain (in that order). These five countries together account for over 80 % of the Community textile and clothing industry [113, EURATEX, 1997].
Table 1.2: Country breakdown of the EU-15 textile and clothing industry in 2000 The textile and clothing chain is composed of a wide number of sub-sectors covering the entire production cycle from the production of raw materials (man-made fibres) to semi-processed materials (yarns, woven and knitted fabrics with their finishing process) and final/consumer products (carpets, home textiles, clothing and industrial use textiles).
The complexity of the sector is also reflected in the difficulty of finding a clear-cut classification system for the different activities involved. The old nomenclature system (old
NACE 1995) still classified textile industry’s activities as follows:
· man-made fibres industry · wool · cotton · silk · flax/jute · knitting · finishing · carpets · other textiles · household linen.
The new nomenclature system (NACE 1997) identifies the following categories:
· yarn and thread · woven fabric · textile finishing · home textiles · industrial & other textiles (this includes Carpets and Wool Scouring) · knitted fabrics & articles.
The old nomenclature reflects the historical subdivision of the textile industry’s activities according to the fibre processed. This stems from the fact that historically the only textile fibres available were natural fibres, with a predominance of wool and cotton, which resulted in the development of two main sectors, wool and cotton. Because of the different physico-chemical characteristics of these two fibres, different machinery and different techniques were developed.
Nowadays, with the proliferation of man-made fibres these two historical sectors now both
process all available fibres and it has become impractical to classify textiles activities by reference to the fibre.
As for the scope of this document, it is confined to those activities in the textile industry that involve wet processes. This means primarily activities falling within the following new NACE
· textile finishing · industrial and other textiles (including Carpets and Wool Scouring) · home textiles.
Because of its very specialised nature, carpet manufacturing has always been considered as a stand-alone sector, even though many of the operations carried out are very close to those carried out elsewhere in textile finishing. This document follows that tradition, hence carpets are the only sector where the end-product is taken as the point of reference.
Some general information is given below about the three sub-sectors of wool scouring, textile finishing (excluding floor-coverings) and carpets.
1.1 Wool scouring sector 1.1.1 Sector organisation Wool is processed to yarn mainly via two systems: woollen and worsted. Scourers tend to specialise in wools for one system or the other. Woollen system scourers normally only scour the wool, though some may blend it before despatch to the customer. Worsted system scourers (referred to as combers) scour, card and comb the wool and their product is called top.
Within Europe, significant quantities of wool are obtained from the skins of slaughtered animals by fellmongering. Fellmongers normally sell the wool they produce to merchants, who have it scoured on commission. In France there are several fellmongers who also scour the wool they produce.
The wool scouring and combing business in Western Europe is largely carried out on commission. There are a few exceptions to this system, notably in the UK, where three carpet yarn manufacturers have their own wool scouring plants.
1.1.2 Production and economics Table 1.3 shows estimates of the amounts of wool produced and scoured in the various Member States along with the number of existing scouring mills.
Unit: ‘000 tonnes/year (a) Included in “Other western Europe”.
(b) Austria, Belgium, Denmark, Finland, Iceland, Luxembourg, Malta, Netherlands, Norway, Sweden and Switzerland.
(c) Assuming an average yield of 70 %.
(d) A second scouring/combing mill in Germany is not believed to be operational.
Table 1.3: Wool production and wool scouring production in EU Member States [187, INTERLAINE, 1999] As it is possible to see from the reported data, ca.
90 % of the EU scouring activity is concentrated in France, Germany, Italy and UK, while eight EU Member States have no scouring plants.
The UK scouring and combing industry is the largest in Europe, though only slightly larger than that of Italy. About two thirds of the UK scouring production comprises coarse wools for woollen spun carpet yarn.
Figure 1.1 shows the amounts of wool scoured in the 15 EU Member States in terms of greasy wool weight.
This is the unit most often used by scourers to express their throughput.
During the period from 1993 to 1997 the total production in EU Member States has declined almost 10 % from 326 million kg (clean wool) in 1993 to 300 million kg (clean wool) in 1997.
Within this overall trend a steeper decline has been observed in northern Europe (Belgium, France, Germany and UK) alongside an increase in production in Italy and Spain. Although the overall decline in production in the European scouring sector has been relatively slow, there have been significant structural changes. The competitive nature of the industry and the cost and technical difficulties of complying with increasingly stringent environmental legislation have been the driving force behind these changes. Several large and small scouring mills have been forced beyond the limits of commercial and economic viability and have ceased trading. In most cases, their market share has been absorbed by competitors, so that now there are fewer companies in the sector, which on average process larger amounts of wool. This tendency towards consolidation is especially true in the UK, where a large part of the scouring industry’s trade is the processing of UK and Irish wools. Almost 80 %1 of the British and Irish wool production, totalling 90000 tonnes is scoured in the UK and this trade is unlikely to be lost to competitors in other countries [187, INTERLAINE, 1999].
1.2 Textile finishing sector (excluding floor covering) The following information is taken from [278, EURATEX, 2002].
1.2.1 Sector organisation The essence of textile finishing is giving fabrics the visual, physical and aesthetic properties which consumers demand. The main processes involved are bleaching, dyeing (of yarn, fabric, ready-made garments), printing, coating / impregnating and the application of various functional finishings.
A survey of UK wool scourers, carried out by ENco in 1997, showed that they processed 71 million kg (greasy) of British and Irish wool during the previous year.
Textiles Industry 5 Chapter 1 In most cases, the textile finishing process is combined with a manufacturing process, which gives the final product its particular shape. The main product categories cover clothing textiles, interior textiles (furnishing fabrics, curtains and carpets, which are discussed in Section 1.3), household textiles (bed / bath and table linen) and technical textiles (automotive fabrics, geoand medical textiles).
Most companies in the textile finishing sector specialise in one type of process, although there are companies with several production processes. The following main types of companies can
· commission or merchant yarn dyers · commission or merchant fabric dyers · commission or merchant printers · integrated companies, incorporating spinning and / or weaving plus finishing processes.
1.2.2 Production and economics
The total turnover of the EU-textile finishing industry amounted to nearly 11000 million euros in 2000, with more than 117000 employees. The majority of EU textile finishing companies are SMEs. The importance of the Textile Finishing Industry in EU Member States is shown in Figure 1.2.