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Throughout the supply chain, there is interest in conserv-

ing resources and reducing the textile industrys environ-

mental ootprint. Every stage o a textile products lie cycle

has environmental impacts rom fber production through

manuacturing and retailing to laundering and disposal by

consumers. O particular concern is the use o water, energy,

and chemicals (WEC) in textile processing an area where

technological advances oer signifcant savings in resources

and environmental benefts. In cotton textile processing,

dyeing and fnishing have the largest WEC requirements andthereore oer the greatest scope or reductions.

INTEREST IN SUSTAINABLE TECHNOLOGIESResearch by Cotton Incorporated indicates that while con-

sumers have become more environmentally aware, their un-

derstanding o textile manuacturing and its eects on the

environment is limited, as is their willingness to pay more

or environmentally riendly textile products. According to

Cotton Incorporateds 2010 Environment Survey, only 36%

o consumers said they would be willing to pay extra or en-

vironmentally riendly clothing.

Despite limits on consumer awareness and motivation, it

is in the textile industrys interest to adopt practices to re-

duce the use o water, energy, and chemicals, especially in

dyeing and fnishing. Cotton Incorporated recently surveyed

representatives o global mills, brands, and retailers abou

their motivations or adopting sustainable cotton technolo-

gies and practices. About two-thirds o these companies are

currently implementing sustainable practices or technologies

(61%) and/or working with supply chain partners that are

implementing them (66%). When asked to identiy the mainreason or their interest in sustainability, the most common

response was concern or the environment 42% said tha

it was better or the environment. Another 14% cited sup

ply chain customer demand, and 11% said it would provide

a competitive advantage; 16% said they were still exploring

the potential benefts.

During the winter o 200809, Cotton Incorporated con

ducted in-depth interviews with more than 40 global cot-

ton textile processing companies that account or over 75%

o global textile processing. These companies manuac

ture a wide range o woven, knit, denim, and yarn prod-

ucts and have implemented changes in their processes, dyesand chemicals, equipment, and control systems that signif-

cantly reduce requirements or water, energy, and chemicals

In this issue, we highlight two proven commercial technol

ogies that survey respondents identifed as having a po-

tentially high impact on WEC reduction: (1) high-fxation

reactive dyeing with reduced salt and (2) low-liquor-ratio je

dyeing machines.

HIGH-FIXATION REACTIVE DYEING, REDUCED SALTReactive dyes contain a reactive group that orms a chemi

cal bond with cotton fber under alkaline conditions. Reac-

tive dyes give bright, ast colors, and account or over 70%

o the dyes used or cotton. However, large quantities o sal

are needed to cause the dye to move rom the dye bath to the

fber, and the exhaustion and fxation rates or reactive dyes

(the percentage o the dye that moves rom the dye bath onto

the fber and the percentage that bonds permanently to the

fber) are relatively low. For conventional reactive dyes, the

fxation rate is oten less than 80%, resulting in waste o dye

and removing the unfxed dye requires extensive rinsing and

washing with heated water.

COTTON INCORPORATED

SUSTAINABLE DYEING SOLUTIONS

2010 Cotton Incorporated. www.cottoninc.com INFO: Global Product Supply Chain 919.678.2262

INSIGHTS

COTTON INCORPORATED SUPPLY CHAIN

Winchester&Associates,2008

WEC USE IS GREATEST FOR DYEING & FINISHING

Distribution of water, energy & chemical use in textile processing

(% of total use)

Water Energy Chemicals

Garmentmanufacture

Dyeing &

nishing

Fabricproduction

Yarn spinning

22

12

1

65

8 85

8085

2

10

2

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These machines usually use low-riction Teon internal coat-

ings and advanced spray systems to speed rinsing. Ultra low

liquor ratio jet dyeing machines operate at a liquor ratio o

less than 6:1 and almost always depend on orced airow to

convey the abric through the machine.

LLR jet dyeing is widely used in high volume or piece

dyed knits, as well as some wovens, depending on abric

weight. Compared with conventional machines, LLR ma

chines usually enable reduced cycle times and increased pro

ductivity, while requiring less than hal as much water. Some

plants achieve our batches in 24 hours (depending on depth

o shade) and average water consumption o less than 50 li

ters per kilogram o knit abric. Plants using machines with

the newest airow technology report processing with liquor

ratios o less than 4:1. One actor limiting implementation is

the high cost o the new machines, which avors use at new

acilities rather than as replacements or older machines.

Low-liquor-ratio jet dyeing machines

Applicability Knits & wovens

Potential WEC Reduction Water: high

Energy: high

Chemicals: moderate

Investment & Payback $200 K $500 K, 2 to 5 years

TOWARD A SUSTAINABLE FUTUREAdvances in making dyeing technology more environmen-

tally riendly have not been limited to improvements in dyestus and equipment. In addition, the plants that are the

most advanced in reducing WEC pursue a combination o

options including high-efciency management practices, pro

cess control, special processes, and treatment and recycling

o wastewater. Each plant adopts options compatible with

its particular product oerings, economic circumstances, en

vironmental regulations, and supply-chain requirements

Achieving these WEC reductions has required plants to learn

and adapt to new processes and practices and to implemen

creative means or ensuring acceptable economic returns.

The cotton textile industry can reduce its WEC envi

ronmental ootprint at least 50% by employing technolo-gies currently used in modern plants (as described in Cotton

Incorporateds recent publication A World of Ideas: Tech

nologies for Sustainable Cotton Textile Manufacturing). Co

operation throughout the supply chain rom fber to fnished

product is critical to encouraging and supporting these e-

orts. To view or download a PDF copy oA World of Ideas

visit Cotton Today at Cotton Incorporateds Web site:

http://cottontoday.cottoninc.com/Sustainability-About

Dye suppliers are now oering improved dyes that enable

much higher exhaustion and fxation rates while requiring

less than hal the salt needed with standard reactive dyes.

These high-fxation dyes usually incorporate two dierent re-

active groups within the molecular structure o the dye. Much

progress has been made in commercializing higher-fxation

reactive dyes or dyeing yarns, wovens, knits, and garments.

Some mills have been able to boost their average fxation

rates rom below 70% to over 85%, and fxation rates o over

90% have been reported. However, these higher-value dyes

oten are more expensive than conventional dyes. Also, be-

cause these dyes have higher afnity or fber than do con-

ventional dyes, they can be more difcult to apply uniormly,

and more water may be required or removal o unfxed dye.

As mills gain experience with these new dyes and develop

confdence that they deliver savings in WEC reduction and

mill cost, their use should increase signifcantly.

High-fxation reactive dyeing with reduced salt

Applicability Yarn, knits & wovens

Potential WEC Reduction Water: high

Energy: moderate

Chemicals: high

Investment & Payback < $200 K, < 2 years

LOW-LIQUOR-RATIO JET DYEING MACHINESHigh-fxation reactive dyes most oten are used with con-

ventional equipment, but their benefts in WEC reductionare magnifed when they

are used in low-liquor-

ratio (LLR) jet dyeing

machines. Jet dyeing ma-

chines are based on the

principle o accelerating

water through a nozzle to

transport abrics through

the machine. They are

designed to operate ef-

ciently and at high qual-

ity with a very low ratio owater to material. Jet dye-

ing machines have been

used commercially or 40

years; however, techno-

logical advances have re-

duced water requirements,

and machines o newer

designs operate at a li-

quor ratio o less than 8:1.

COTTON INCORPORATED 2010 Cotton Incorporated. www.cottoninc.com INFO: Global Product Supply Chain 919.678.2262

SUPPLY CHAIN INSIGHTS

SUSTAINABLE DYEING SOLUTIONS

Low-liquor-ratiojetdyeingmachine