produced for defra sustainable clothing roadmap by phil...

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Eco-efficiency of Indian Dyehouses

Final Report

Produced for Defra Sustainable Clothing Roadmap by

Phil Patterson

Colour Connections Textile Consultancy

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Contents

1. Introduction (page 3)

a. Criteria for dyehouse selection

b. Background information

i. Information on the Tirupur regional dyeing industry

ii. Cotton dyeing processes

iii. Basic dyehouse infrastructure

iv. Dyehouse inputs and outputs

2. The Project (page 14)

a. Dyehouse screening summary (page 14)

b. Details of selected dyehouses (page 16)

c. Project Progress (page 16)

i. Dyehouse #1 (page 17)

1. Summary

2. Action Plan

3. Data analysis

4. Reduction of environmental impacts and cost savings

ii. Dyehouse #2 (page 29)

1. Summary

2. Action Plan

3. Data analysis


iii. Dyehouse #3 (page 37)

1. Summary

2. Action Plan

3. Data analysis


3. EcoMetrics (page 44)

4. Best practice seminars (page 47)

5. Key best practice emerging from the project (page 49)

6. Summary of project (page 50)

7. Recommendations for future Eco-efficiency projects (page 50)

8. Appendix

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1. Introduction

This demonstration project is part of the Defra co-ordinated Sustainable Clothing Roadmap, voluntary

industry initiative to improve the environmental and ethical performance of clothing across its supply chain http://www.defra.gov.uk/environment/business/products/roadmaps/clothing/index.htm

Because 90% of clothing consumed in the UK is imported, encouraging environmental and ethical

improvements across the international clothing supply chains feeding the UK is essential for improve the

sustainability of clothing we wear in the UK. India is the second largest manufacturer of clothing imported

into the UK. For this reason, demonstration projects have been funded under the Sustainable Development

Dialogues http://www.defra.gov.uk/sustainable/government/international/dialogues/ to support

knowledge sharing and dissemination on key issues between UK /India supply chains. This project focused

on demonstrating the environmental and business case for eco-efficiency in Indian dyehouses supplying the

UK clothing market and was funded by Defra as part of the UK-India Sustainable Development Dialogue.

Dyeing is recognised as being a high impact process that consumes large quantities of water, energy and

chemicals, and the dyeing industry is known to be one of the major global polluters.

The project set out to select three dyehouses of differing ability and to work with them to reduce the

amount of water, energy and chemicals used to dye their products by:-

Improving Quality

Improving Efficiency

Implementing Green Initiatives

The project had two broad aims:-

1. Identify opportunities to improve the performance of the selected dyehouses

2. Develop and disseminate best practice for use by the wider dyeing industry

Criteria for Dyehouse Selection

In order to maximise the time spent with the dyehouses it was decided to select three dyehouses from the

same region of India.

It was also decided to select dyehouses from the same industry sector - to enables easy and reliable

comparisons between the selected dyehouses to be made.

Tirupur was chosen for the project because it has unique and interesting local challenges and, since it is

renowned as a centre for T-shirt production, the selected industry sector was jet dyeing of weft knit cotton.

The project is supported by three UK retailers, Marks and Spencer, Tesco and Next.

Each retailer put forward a shortlist of their preferred suppliers in the region and a total of nine dyehouses

were screened for inclusion in the project.

The original aim was to select one ‘excellent’ dyehouse, one ‘good’ dyehouse and one ‘poor’ dyehouse but

none of the dyehouses suggested by the retailers fell into the ‘poor’ category.

http://www.defra.gov.uk/environment/business/products/roadmaps/clothing/index.htm

http://www.defra.gov.uk/sustainable/government/international/dialogues/

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This was not a major problem but it must be recognised that there are many more poor dyehouses in the

world than good ones, and an opportunity was lost to demonstrate some of the easy, quick wins that can

be achieved with poorer dyehouses.

The three project dyehouses were chosen in consultation with the retailers having first considered the

opportunity to improve and the willingness of the senior technical management to try to improve.

Full details of the initial assessments of the shortlisted dyehouses are provided in the appendix.

Background Information

In order to understand some of the details in this report a basic explanation of cotton dyeing processes and

how a dyehouse works is provided.

Some details of the specific local challenges faced by the Tirupur industry are also provided to enable the

reader to fully understand the differences between this region and the wider dyeing industry.

Information on the Tirupur regional dyeing industry

The Tirupur region has been selected for the project on the basis that it is an area that has been subjected

to a large degree of environmental damage as a result of the high density of cotton dyehouses that have

that have been operating in the area.

Tirupur is a relatively dry area and the rivers are not even sufficiently full to give reasonable dilution to

contaminants in treated dyehouse effluent, let alone the untreated effluent that has been discharged by

significant numbers of dyehouses until the very recent past.

Tirupur is the centre of the weft knit cotton industry (T-shirt type fabrics) and the by-product of typical

cotton dyeing is lots of unfixed dye and lots of salt in effluent.

Normal effluent treatment will remove colour, but not salt - so even the dyehouses who were treating their

effluent to levels that would be accepted throughout most of the world were still adding the environmental

problems by discharging vast amounts of salt.

The past few years have seen a remarkable change in the region and dyehouses have had to clean up their

act.

This change was catalysed by the people of the region who became so concerned about the pollution being

caused by the unregulated dyeing industry that they took their case to the courts and won.

It is therefore the courts who enforced the clean-up programme and they have had huge success to date in

moving the industry forward.

The courts and government are now working in unison to deliver a balanced package of incentives and

punitive measures to keep the economy moving whilst reducing environmental impacts.

Almost all dyehouses in the region now have to be zero discharge factories, or they have to discharge their

effluent to a communal zero discharge effluent treatment plant – under the conditions of their operating

permits they are not allowed to discharge one drop of even fully treated effluent.

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At the start of this project in Spring 2009 there were still mills that discharged partially treated effluent into

the rivers (colour removed but other contaminants remaining) and their hours of operation were severely

restricted but this situation is now coming to a close and all dyehouses have to be zero discharge in 2010.

Despite the closure of over 150 polluting dyehouses in the two years running up to the project, local

experts are still convinced some mills are illegally discharging completely untreated effluent into the rivers.

Several Central Effluent Treatment Plants (CETP’s) were closed down in early 2010 because they had not

met the stringent standards for zero discharge and this caused the temporary closure of even more

dyehouses, including one of the dyehouses selected for the project.

Pollution is a major issue for the global textile industry, and some respects it would have been better to

include a polluting dyehouse in the project as a case study.

However the best practice being employed in the Tirupur area is so good, in many respects it is THE ideal

place, worldwide, to conduct a project with a view to sharing the best practice with the wider industry.

There are still major environmental challenges for the industry and society in the Tirupur region, namely a

scarcity of electricity and a scarcity of water.

Dyehouses do not get electricity for 24 hours a day and have to generate their own using diesel generators

when the supply is cut off - this is inconvenient and much more expensive than electricity from the

government grid.

Improving the efficiency of processing in dyehouses, the major industry of the region, can alleviate a real

societal problem as well as providing better profitability for the dyers.

Cotton Dyeing Processes

Cotton dyeing is generally accepted as having the greatest negative environmental impacts of all dyeing

processes. The most common method for weft knitted cotton (the type used in T-shirt type fabrics) is a

method called jet dyeing and all the dyehouses considered for the project use these machines.

A long length of fabric (up to 1km in the largest machines) is sewn together in a loop and this is propelled

around a machine using pulleys and jets of hot water containing the dyes and chemicals used in the

process. In the schematic diagram of a jet dyeing machine below the fabric is shown in red and the hot

water circulation and jet system is shown in blue. (Manufacturer –Thies GmbH)

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A typical (but not world class) jet dyeing process is outlined below:

Jet dyeing machines use electricity to run the motors, pulleys and pumps and the longer a process takes,

the more electricity is used. Processes normally operate on the principle of sequential filling and draining of

the dye machine and each time the machine is refilled it is referred to as a new ‘bath’. The water in the

machine is heated by steam, so it follows that processes that have more baths and/or hotter baths use

more steam and each bath typically contains between 5 and 10 times as much water as fabric (by weight).

Using less water per kg of fabric means less steam has to be used to heat the water, and the water can be

heated up more quickly thus saving time and electricity. Since most chemicals are used on a g/l basis the

use of fewer litres of water means the use of fewer chemicals – thus reducing effluent loading.

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The class of dye used to produce high quality T-shirt type fabrics are called reactive dyes and these require

large amounts of salt in order to get the dyes to be attracted to the cotton in a dyebath – and then large

amounts of alkali to get the dyes to permanently fix to the fibres.

At the end of the process the dye that is not fixed to the fabric, but is still sitting on the surface, has to be

removed to deliver satisfactory colour fastness but it cannot be removed in the presence of salt – since the

salt actually ‘pushes’ the dye onto the fibres. Therefore a long, water and energy intensive process has to

be employed to remove the salt before the unfixed dye can be removed, and this results in the wash-off

phase typically accounting for over half the time of the total process.

When a dyer is asked to produce fabric of a given colour they will first carry out a dyeing in a laboratory on

a 5 or 10g sample of fabric. Once this colour is approved they will scale up to bulk dyeing. The first time a

bulk dyeing is produced on a particular colour there is a chance it will be wrong – and dyers should measure

their lab to bulk scale up success rate. Once a colour is established in bulk it is easier to guarantee

consistency and the overall right first time figure for their total production, including new and established

colours, is another important quality measure.

Dyeing fabric the wrong colour uses just as much energy, water and chemicals as dyeing it the right colour,

and is a major unnecessary contributor to environmental impacts.

After dyeing the fabric is unloaded from the dyeing machine and excess water is removed by either a

mangle:-

Or a spin dryer.

Finally the fabric is dried on a continuous drying machine called a relax drier. Fabrics typically have between

70% and 100% of their own weight in water after the mangling or spin drying and the lower the amount,

the less energy is required for final drying.

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Some fabrics undergo further processes where chemicals are put on the surface of the fabric but most T-

shirts undergo a fairly simple dye-hydroextract-dry process and all the factories involved in this study use

this method for the majority of their fabrics.

Dyehouse Infrastructure

In order to carry out dyeing and drying processes any dyehouse, anywhere in the world requires:-

Electricity to run the dyeing machine machines, drying machines and effluent treatment plants

o Large blowers, high pressure pumps and Infra Red dryers (for yarns) are the largest

consumers

Steam to heat the water in dyeing machines (produced by an industrial boiler powered by wood,

coal, electricity or gas)

A method of heating drying equipment

o In most factories electrically powered blowers distribute heat produced by burning oil or

gas

o In Tirupur most factories use a thermic flue (where hot oil, heated by a wood fired boilers,

is circulated around machines)

A reliable supply of high quality soft water

o Water is often softened on-site

Compressed air to operate valves on machines

A reliable supply of dyes and chemicals

o Cheap dyes and chemicals save money on dye and chemical bills but are usually a false

economy because they are inconsistent and lead to costly mistakes

A method of treating effluent to comply with local regulations or access to a central effluent

treatment plant

o The exact design depends on local conditions and regulations but the treatment plant has

to remove colour, COD (oxygen depleting substances) and suspended solids.

Effluent treatment is becoming more expensive and many dyers are looking at ways to reduce the amount

of chemicals in effluent - mainly to reduce cost rather than an altruistic environmental move.

Water is primarily used in machines to bleach, dye and wash fabric but it is also used to generate steam and

in cooling systems.

Most dyers try to recycle cooling water and steam condensate to reduce their overall water consumption

(failure to do so can double water usage) and it is becoming more popular to try and use special heat

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exchangers to recycle heat energy that would normally be lost up a chimney or when hot water goes down

a drain.

Inputs and Outputs

Dyehouses can be considered as very simple ‘black box’ model with inputs, activities and output.

The aim of this project was to improve the efficiency of the activities to minimise inputs and negative

outputs

In order to improve the efficiency of a dyehouse it is important that data is collected to measure and

monitor certain key performance indicators.

Improving performance KPI’s has a direct effect on the consumption of the inputs but there are other

initiatives that are largely independent of product quality and factory efficiency that have a significant

effect (such as the purchase of new boilers and heat recovery).

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Input Detail

In many areas of the world the resources are ‘on-tap’, and there is a readily available supply of the water,

power and fuel a dyehouse needs to operate that can be provided without catastrophic local impacts on

the environment.

However in other areas of the world the use of resources by industry is causing severe local environmental

impacts and is also depriving the local population of water and electricity - as was the case in Tirupur until

recently.

The industry in Tirupur has been forced to recognise that there are finite quantities of water, power and

fuel in their region and there are particular restrictions in place.

Water

Industry in the region is largely reliant on water that is piped in by the government from 60 km away.

Abstraction of water from local rivers is not permitted and the use of bore hole water (that can lower the

water table) for industrial use is severely restricted.

Despite many factories being zero discharge, and therefore nominally recycling their water for re-use, there

are losses of approximately 20% of process water (by evaporation) and this has to be purchased from the

government pipeline.

The cost of water varies, with higher prices being charged for dyehouses in a municipal setting than those

in Government industrial zones such as SIPCOT.

SIPCOT (State Industries Promotion Corporation of Tamil Nadu) is based in Perundurai - and is a fully

government owned institution, established to catalyse development of small, medium and large scale

industries in Tamil Nadu. http://www.sipcot.org/ ). It provides infrastructure and some concessions to

dyehouses who re-locate from municipal areas.

Electricity

Electricity is in short supply in this part of India. A rapidly growing population and rapid increase in the

standard of living means that demand outstrips supply, and the region generally works on a system of

rationing.

For prolonged periods of each day the Government electricity supply is turned off and individuals and

industry either go without power or resort to the use of local generation.

Dyehouses typically have diesel powered generators to supplement the government supply and also

capacitors to store electricity to ensure that machines and control systems are never without power.

The consumption of diesel in power generation is not insignificant, and dyehouses report that their own

electricity costs up to 2 or 3 times as much as that provided by the government.

Dyehouses are assessed to see what their capacity and electricity needs are and they are allocated a

percentage of that requirement by the government, with the balance being generated on-site. Throughout

the period of the project this has varied from 10 - 40% being generated on site.

http://www.sipcot.org/

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It is possible to generate renewable electricity in other areas of the country and off-set this but

interestingly this does not mean they get more electricity, but it does mean that they get cheaper

electricity – the only way to make the allocated electricity go further is via dyehouse efficiency measures.

Boiler Fuel

In order to run a dyehouse you need electricity to run machinery and you need to generate steam to heat

the process water.

Steam is generated in a boiler and is transported through pipes to the machines where heat is transferred

to the water in the machine by means of a heat exchanger. (a series of pipes that take heat from the steam

and transfer it to the water without the steam coming into contact with the process bath).

The main factor in deciding what type of fuel is used for the boiler is price.

Gas and oil fired boilers are probably the most efficient in terms of the ease with which the fuel can be

dosed into the boiler to match the steam requirements of the factory, but gas and oil is so expensive in

Tirupur that no-one uses these fuels.

The majority of boilers in the Tirupur region use firewood.

It is difficult to control the output of wood powered boilers - the steam requirement of the dyehouse

(which varies depending on the number of dyeing machines that need heating up at any stage) has to be

approximately matched by the manual addition of wood to the furnace so efficient use of fuel is difficult to

achieve.

Unlike modern gas boilers many of the firewood boilers have little or no insulation, so a significant amount

of the heat generated does not in fact go to producing heat, but is merely lost to the surroundings.

It is apparent that some dyehouses simply feed the furnaces with firewood on a continuous basis

irrespective of steam requirement.

The calorific value of wood is less than that of coal, oil or gas, particularly if there is moisture in the wood,

and some dyehouses report that they find it difficult to heat up process water as quickly as they would like.

Machines still run during slow heating and so consume more electricity than machines that can be heated

quickly.

Wood can be a good fuel since it from a renewable source and all dyehouses report that the wood they use

“comes from Government approved sources”, the inference being that the wood is being sustainably

managed.

Although this project sets out to reduce the amount of resources used to produce dyed fabric rather than

passing judgement on the types of fuel used it is important that the nature of the forestry is examined

more closely as it could be a major factor on whether the regional industry has an overall high or low

impact.

This is especially important because dyehouses are now switching to coal powered boilers because coal

works out cheaper in terms of Rupees/ kg steam.

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Coal is a better fuel in terms of heat output per unit of feedstock but is quite obviously a non-renewable

resource so it would make sense for the economics to be adjusted to make the most sustainable fuel the

most cost effective.

For the wider industry electric boilers are also worthy of consideration, primarily because electricity can be

generated by sustainable energy such as wind power and solar.

However since dyehouses in Tirupur have their electricity rationed they would need to site wind farms on-

site to get a benefit.

The other inputs of dyes, chemicals and fabric will be considered as part of the dyehouse process as they

are inextricably linked.

Dyehouse Outputs

Water Vapour

Approximately 20% of the water lost by evaporation during:-

Dyeing

Drying

Effluent Treatment

Effluent

Dye effluent contains dye, salt, and other chemicals used in processing - these are the major constituents of

Colour, TDS (total dissolved solids) and COD (chemical oxygen demand).

Until recently it was acceptable for dyehouses in Tirupur to remove the colour and dump the salt and

chemical-containing effluent into the river – but no more.

There are a variety of colour removal techniques including flocculation and sedimentation, ozonolysis and

chlorination (the reality is that colour is a minor environmental issue but a massive aesthetic issue – it is the

things that you can’t see that should cause concern).

COD, a measure of the amount of oxygen depletion potential of the chemicals in effluent, can be reduced

by biological treatment plants, where microbes digest the chemicals and break them down into species that

have less potential to rob the rivers of essential oxygen.

However the problem is salt, which is not removed by any standard effluent treatment techniques.

The only way to satisfactorily remove salt from effluent is by reverse osmosis (osmosis is where water

travels across a semi-permeable membrane into a more concentrated solution of salt and reverse osmosis

is the opposite where water is ‘squeezed out’ of a salt solution by forcing it through a semi-permeable

membrane under pressure).

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Reverse osmosis leaves a residue of highly concentrated salt solution from which water is removed using a

highly costly and energy intensive evaporation process - however both the condensed water and recovered

salt can be re-used in the dyehouse.

Dyehouses who treat their own effluent essentially have two build two factories: one to dye the fabric and

one to treat the water. There is a large capital investment, but from then on the costs are manageable, but

still significant, in terms of energy, chemicals and replacement parts.

The major benefit is that 70-80% of their water needs are met by themselves, thus making more water

available for the rest of society.

Dyehouses who send their effluent to a communal effluent treatment plant for processing have to pay

approximately 150 Rupees per m3 for their effluent to be treated and it can be returned to them for

processing (the communal plants also have to be zero discharge).

The one thing that remains to be resolved is sludge – this is the solid residue that remains after treating

effluent and is comprised of one or more of the following: biological sediment from biological treatment

plant, chemical sediment from chemical flocculation and filtration processes, and contaminated salt (that is

the ultimate residue of the reverse osmosis and salt recovery process).

Most dyehouses are currently storing sludge on-site in bunded landfill areas, awaiting news of disposal

recommendations - but the more enlightened ones are developing processes to minimise the creation of

sludge.

Air Emissions

Burning wood, coal and diesel creates CO2 and particulates.

There are mixed reports on the issue of air pollution that requires further investigation. Some mills claim

that there are no requirements with regard to air pollution provided the chimneys are sufficiently high and

other report monthly inspections by the authorities.

Solid Waste

Burning wood produces lots of soot and ash. This is collected and either disposed of or stored.

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2. The Project

Dyehouse Screening Summary

Dyehouses on the retailers’ shortlists were screened in April 2009.

Specific information relating to the individual screened dyehouses are provided in the appendix but there

are some general points worth making with regard to the dyehouses that were been screened.

Each of the retailers who supported the project has standards they expect of their suppliers, and they also

have teams on the ground to assess and monitor factory and product standards.

The shortlisted dyehouses were therefore from the better end of the industry where factories, systems and

products are better than average.

Some of the local garment manufacturers reported that they do deal with dyehouses that are of a much

lower standard than those screened for this project.

At the time of screening the concept of efficiency and quality had already been forced on the dyehouses by

the pollution standards and scarcity of water and electricity.

Some dyehouses had some key measures in place but in general hard facts were difficult to obtain, with

several mills giving estimates that were unlikely to be accurate.

The Process Systems i.e. those to get a batch of fabric through the production process were generally

sound, but the Quality Systems i.e. those that record pass/fail data, problems, timings, efficiency and

resource utilisation were generally in need of improvement.

One of the main reasons for poor quality data is that there was confusion between what was acceptable by

a customer (commercially OK) and what met the technical standards laid out by the customer (technically

OK).

The only way to improve is to aim to meet technical standards and measure performance against those

standards.

Some of the dyehouses that were screened are part of vertical garment organisations and so they are

essentially their own customer – this can lead to acceptance of things by the garment factory that are

subsequently rejected by downstream retail customers and the failure figures are not likely to be recorded

at the dyehouse.

Colour laboratories were generally very well equipped in terms of weighing, dispensing and machine

control.

Colour matching generally seemed to be done visually in most dyehouses, and in order to become world

class dyehouses must use instrumental colour measurement as their main method of pass/fail assessment

for laboratory and bulk dyeings.

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Those that did use instrumental colour measurement had mixed levels of ability and only one of the

dyehouses screened had a conditioning cabinet – a prerequisite for world class colour measurement.

The standard of bulk dye storage, weighing and dispensing was mixed, but generally adequate. Some had

conditioned rooms and check-weigh systems but most operated on a manual basis. Most dyehouses

claimed to be using top quality dyes in order to achieve their quoted right first time figures but examination

of the dye stores often revealed a majority of local, lower quality dyes.

No in-depth checks were done on chemicals as part of the screening process but most did come from the

reputable international suppliers who provide good safety and technical data.

Most dyehouses would like to shorten their dyeing cycles. When the industry is doing well and orders are

good shortened dyeing cycles provide extra production capacity, subject to availability of electricity and

effluent consent levels.

In the dyehouses that were screened, typical dyeing cycle times varied between 8 and 12 hours – the

shorter times being achieved by those with pre-heated hot water and sophisticated machine control.

One aspect which continues to halt progress is the slavish adherence to dye companies’ salt

recommendations for reactive dyeing.

Dye company salt recommendations are robust and far too safe. They were derived decades ago before the

advent of sophisticated dyehouse control systems and concentrations could easily be reduced with no

negative effect on quality.

The majority of water is consumed on washing off of reactive dyes and less salt in the dyebath means less

water is required for washing off - and also cycle times can be reduced. Reduced cycle times mean reduced

electricity consumption (the motors and pumps are running for less time) and reduced salt of course means

lower chemical consumption and lower effluent loading.

Salt in effluent is also an issue with regard to the high cost of running zero discharge facilities so it is

therefore surprising that the majority of screened dyehouses had not looked at this issue in more detail -

particularly those with on-site ETP’s.

There was limited evidence of heat recovery initiatives, either from effluent of from finishing equipment

such as stenters and driers.

Most of the dyehouses evaluated had very little finishing equipment since their products were mainly pure

finish cotton. There is a small amount of stretch fabric produced in the region, that requires more stenter

capacity, but there was very little evidence of performance chemical finishes being applied or even

peaching and sueding.

Several dyehouses reported that they send dyed fabric to other third party factories to finishers, en route

to the customer. This is one of the contributors to the less than perfect quality measurement attitude -

since they don’t carry out the last process before garment making they absolve themselves of some of the

responsibility for quality judgements and monitoring.

Examination departments, absolutely essential as part of a quality improvement process, were almost non-

existent. The garment factories carried out this role for the vertical operations and the customers carried

this out for the commission dyers.

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One dyer in a vertical organisation reported that 2.5% of garment panels were rejected in their garment

factory – a massive cost that could have been highlighted at the dyehouse stage.

The quality of testing Laboratories was mixed. Some had fully equipped, accredited laboratories and other

had very basic QC and rely on customers, garment facilities and third party laboratories to do the checking.

The danger of not having a lab is that the dyehouse can equate a commercial decision (agreeing to take off-

specification merchandise) as an endorsement of a faulty process.

There is a concern that the provision and use of personal protective equipment is almost non-existent, and

one has to be concerned that if safety instructions are ignored then technical instructions may also be

ignored, resulting in unnecessary product failures.

Despite the points raised above the screened dyehouses were very good, with some talented individuals in

place, but they have got potential to improve.

Several dyehouses were processing organic cotton. Although of secondary importance to the project, GOTS

certification is a good indicator that dyehouses understand the concept of controlling restricted substances.

Selected Dyehouses

The following three dyehouses were selected for the project because, although they had some common

areas for improvement, they needed to focus on different aspects to reduce their environmental impacts.

Dyehouse # 1 is part of a vertical group who have good quality and efficiency. They have evaluated

investments in infrastructure and new technology in addition to quality initiatives to further

improve their environmental performance.

Dyehouse # 2 is a busy commission dyer, with reasonably good processes and levels of efficiency.

They have primarily focussed on improvement in right first time performance and hardware

upgrades to reduce environmental impacts.

Dyehouse # 3 is part of a vertical group who reported high levels of quality and right first time. They

primarily needed to optimise their processes and dyehouse planning to reduce environmental

impacts.

Project Progress

The three selected dyehouses were examined in detail in June 2009 using the ICE Compliance dyehouse

auditing methodology to evaluate opportunities for improvement and an action plan was developed for

each one.

The purpose of the detailed evaluation was to:-

1. Establish baseline performance (quality and environmental)

2. Develop recommendations and action plans

a. Free of charge actions

b. Capital investments where pay-back calculations are required

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In an ideal world it is advisable to clearly establish baseline performance before implementing action

plans - in order to accurately quantify the benefits of the actions. However because of the very tight

timescales of the project it was necessary to provide action plans before full baseline data was collected.

Further visits were made in September 2009, January 2010 and March 2010 to check progress with action

plans.

The major challenge of this project has been getting reliable data from the dyehouses with only Dyehouse

#1 providing good quality data from an early stage despite a simple pro-forma being produced for each

dyehouse to collect key pieces of information.

Without wishing to make excuses for the dyehouses that did not provide good data it must be understood

that their number 1 priority throughout the project period has been delivering products to their customers

and this project has been very much secondary to their day to day business.

This is a key lesson from the project that is applicable to all sustainability projects - the major challenge is

to make time and money available to allow managers look at long term improvements rather than

focusing on day to day fire fighting. If time cannot be made available by the managers then it can make

long term sense to employ external project teams to identify and implement improvements.

Dyehouse Reports

Dyehouse #1

Dyehouse #1 is a zero discharge dyehouse situated in the Sipcot development that carry out yarn and fabric

dyeing for their own vertical garment company and also some commission work.

They have reasonable quality machines, good machine control systems and use high quality dyes for the

majority of their production.

They have the capacity to dye 8 tonnes of fabric and 2 tonnes of yarn per day and they have been operating

at close to this capacity for the duration of the project.

The quality performance figures quoted at the start of the project indicated that they had limited scope to

improve and at their major focus was on improving the infrastructure of the factory.

However Dyehouse #1 have provided reliable data since the early stages of the project and this has

highlighted opportunities to improve quality and also some unexpected opportunities to improve

infrastructure.

They have shown an excellent attitude towards improving their factory throughout the project and have

carried out many of the actions on their action plan - to their benefit. The factory manager has voiced his

frustration at not being able to make faster progress due to time and financial constraints and has

expressed a desire to continue working with Colour Connections beyond the completion of the Defra

project.

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The action plan below shows everything that has been worked on but a summary of the key actions they

have taken is as follows:-

Data showed lab to bulk reproducibility to be a bigger problem than they thought. They have

improved laboratory procedures to almost halve the number of failures.

Instead of using look-up tables they now use a graph to determine the amount of salt used in

dyeings resulting in a reduction of approximately 5% of salt.

Data has shown that dyeing cycle times are longer than the programmed times and they are

conducting a detailed review of all batches that over-run to identify the reasons.

They are also going to embark on programme to reduce dyeing cycle times by a minimum of 20%

by:-

o Introducing lower temperature enzyme bleaching (Huntsman Gentle Power Bleach) where

possible. Trials have shown it uses less time and energy and has lower environmental

impacts but the overall cost saving is zero due to high cost of speciality chemicals.

o Removing unnecessary high temperature ‘migration’ dyeing methods for some shades

o Evaluating current wash off methods in detail to remove unnecessary wash baths

o Evaluating new wash off detergent technology (CHT) to reduce time and water

consumption

They have established that savings in boiler fuel from quality and process optimisation initiatives

are largely theoretical because the wood boiler cannot be modulated to match steam production

with steam demand. They are now investing in a more controllable coal fuelled boiler that will pay

for itself in less than one year.

They have calculated that the addition of a third reverse osmosis module to their current water

recycling facility will be cost effective. Adding an RO module will cost money and will require extra

electricity to run it but it will reduce the volume of salt solution sent to the evaporators by 20% and

thus reduce the overall energy consumption for effluent treatment.

Dyehouse #1 are now committed to installing Cold Pad Batch dyeing equipment and are currently

assessing quotes from different suppliers. This will use this as additional (low impact) capacity to

supplement their jet dyeing capacity so there will be an increase in total impacts but an overall

reduction in impacts per unit of production.

At the time of the fourth visit in Jan 2010 Dyehouse #1 reported that they were very busy and were

therefore sub-contracting business to other jet dye dyehouses (because of a move to viscose

dyeing which is less productive - see data analysis). Bringing this in-house to a lower impact method

(CPB) would therefore reduce total impacts.

In the action plan below the right hand column indicates whether the dyehouse needs to make an

investment to carry out the action - more detailed costs are available in the ‘Reduction of environmental

impacts and cost savings’ section.

19

Action Progress £

Basics and Minimum Standards

Ensure all operatives wear appropriate personal protective equipment (gloves, goggles, shoes) at all times, including dyehouse operatives

Ongoing monitoring required

Free

Quality Introduce specific gravity checks to confirm salt levels

Now commenced on difficult shades £

Create standardised continuity cards so that batch to batch variations can be easily compared. Include details of right first time / additions/ top ups and DE read-outs on the continuity cards. (more than one format in use and difficult separate card kept for each batch)

Has been actioned and is operational.

Free

Use instrumental colour measurement in the dyehouse to judge pass/ fail rather than using visual assessment alone. Continue to make commercial decisions but record DE failures as failure to get true figures for shade right first time.

Instrumental colour measurement being used in conjunction with visual assessment

Free

Introduce a standardised procedure for colour measurement - including conditioning for temperature, humidity and light.

Now done

Free

Always use the original master standard when judging colour. Even if a secondary standard has been created (to account for compacting) the use of the original master shade will reduce the chance of drifting away from what the customer specified

Not done. Part of reason is that dyehouse only receives tiny cuttings as master standards that are deemed to be almost useless - better standards are now being received from some customers.

Free

Always measure fabrics in the same way - textured fabrics give different results depending on the angle with which they are presented to a spectrophotometer.

Already actioned. Benefits already being reported in terms of ease of decision making

Free

Conduct failure trend analysis to see if particular shades, dye combinations, machines, operatives are a problem and to analyse if problems are hue or depth problems are the major cause of failure. Most problems are reported as being depth problems - this may be due to 'loose' standardisation (shades need to be darker to account for thinning of shade on compacting - but extra depth is not specified)

Data collection is now enabling this process to take place. Even so more detailed analysis is required. Number of bulk failures is low so small amount of data to work with.

Free

Ensure lab dye pot with the temperature probe has additions made to it - even when being used as a blank pot.

Done

Free

Seek permission from customers to submit one lab dye only for approval

Do not want to jeopardise customer relations. Would rather this was raised a neutral best practice seminar

Free

Process Optimisation

Evaluate salt-at start dyeing techniques (enables s.g. Measurement - but must consider additional volume of liquid introduced with dye and alkali)

Introduced to the majority of new bulk shades

Free

20

Look at using reduced salt levels in all dyeings to a) reduce salt consumption b)improve level dyeing and c)provide an opportunity for reducing wash off processes. Do not alter any running bulk shades without thorough laboratory trials.

Not yet done but trials are planned to coincide with s.g. Checks - salt levels from graphs now coming through into bulk.

£

Create a graph for determining salt requirements rather than traditional dosage based on dye concentration bands. This will reduce salt usage by up to 5%

Done

Free

Evaluate the possibility of re-using the final wash off bath in subsequent dyeings (this contains so little dye as to be insignificant compared to the first post-dye wash off bath and so can be used with little risk)

Not started

£

Evaluate the possibility of re-using the post-bleaching wash off bath for post-dye washing

Not started - water recycling and hot water system will now considered after introduction of CPB

£

Reduce in-bath fabric sampling to one after bleaching and one after dyeing and wash off.

Still convinced that multiple samples add benefit. Data analysis has highlighted that cycle times are longer than initially thought (average of 10 hours 15 mins) so this may now be actioned. Over-running processes are now being analysed in detail to establish causes.

Free

Rigorously monitor process times and the % of time taken in sampling and for decision making - consider moving to blind dyeing for certain shades

Free

Factory Planning

Assess and record the real impact of inefficient colour approval processes on the dyehouse. Explain the benefits of a single numerical colour standard to customers.

Don't want jeopardise relations with customers

Free

Take control of your own QC. Try to stop finishing of a sample of each batch for judgment by customers - finish the whole batch and present data to customer telling them it is on specification.

Don't want jeopardise relations with customers

Free

Remove the time allowed for batches to 'condition' after drying - they will not reach ambient conditions in 24 hours

Done Free

Monitor steam and heat requirement of dyeing and drying equipment

Now decided to move to coal powered boiler to match steam output with steam demand - monitoring was free but new boiler is an investment

Monitor fueling of boilers and whether this can be further optimised to match heat and steam requirements

Hardware / Machinery

Investments

Consider purchase of a conditioning cabinet to improve consistency of colour measurement processes

Being considered

£

Consider purchase of electronic dosing pipettes to improve accuracy of lab processes

Done. Now used to make alkali additions to dyepots instead of inaccurate syringes £

Consider replacing mangle rollers to reduce moisture content of fabrics prior to drying - pay back in less than 12 months

Mangle rollers have been reground to squeeze 3% more moisture out of fabric. New rollers being priced up to deliver greater savings

£

Consider investment in moisture meters for relax drier to prevent over-drying and unnecessary use of energy

Moisture meters installed but need attention £

21

CPB Examine cold pad batch to eliminate use of salt in some dyeing processes and reduce energy requirement of evaporator

Successful trails have been completed and they are committed to installation in 2010 £

Assess machine insulation technology to reduce energy requirements e.g. http://www.nansulate.com/

Not done. Cooling is a bigger problem than heating due to hot water returned from evaporator.

£

New Technology

Assess the Huntsman enzyme 'gentle power bleach' to see if preparation temperatures and costs can be reduced

Trial has been completed - will introduce on appropriate fabrics Free

Assess the use of DyStar alkali clearable disperse dyes for use on cotton/poly blends. A

Will be evaluated when next poly/cotton orders are placed £

Assess the use of Cotoblanc SEL 200 in conjunction with CHT technical team to see if wash off processes can be optimised

Trials to be arranged in April 2010

Free

Infrastructure Conduct cost-benefit analysis of heat recovery from stenter and dryers

Basic figures to be discussed with experts such as Koenig - cost benefit analysis will be required

£

Hot water /Heat recovery from effluent

Project is now planned for 2010 - plans have been drawn up and quotes being assessed

£

Data Analysis

The information is split into three sections: quality performance, process optimisation and resource

utilisation.

In some respects monitoring the performance of a dyehouse is like trying to hit a moving target as their

production volumes and product changes from month to month.

The major factors that can skew results are:-

Total production volume - efficiency is nearly always poorer when production volumes are low.

The balance between coloured and white production. Dyeing whites takes approximately half the

time, energy and water as an average colour.

Fibre type - dyers are trying to move away from commodity products such as simple cotton and are

looking at other fibres such as viscose. In the early stages of product development it is common to

employ long, over-safe dyeing methods to reduce the chance of customer dissatisfaction.

Quality Performance

The quality performance of the dyehouse is generally very good. The data analysis early in the project

highlighted there was an issue with lab to bulk reproducibility and steps have been taken to improve

laboratory processes, resulting in a marked improvement in lab to bulk right first time performance*.

Jun July Aug Sept Oct Nov Dec Jan Feb

Fabric 1st Bulk Batches 20 26 50 48 22 18 62 58 50

Fabric 1st Bulk Batches RFT 13 18 35 28 16 11 46 50 42

22

Fabric Right First Time % 65 69 70 58 73 61 74 86 84

Yarn 1st Bulk Batches 77 79 101 114 107 105 147 151 154

Yarn 1st Bulk Batches RFT 62 58 71 98 96 86 135 120 112

Yarn Right First Time % 81 73 70 86 90 82 92 79 73

Total 1st Bulk Batches 97 105 151 162 129 123 209 209 204

Total 1st Bulk Batches RFT 75 76 106 126 112 97 181 170 154

Total Right First Time % 77 72 70 78 87 79 87 81 75

*The figure for fabric right first time shows a steady improvement but the figures for January and February

2010 have been affected by underlying problems in the bulk dyehouse. The fabric figure remains on an

upward track but it is believed the figures for the yarn dyehouse have been affected by a, yet undiagnosed,

underlying problem in the yarn dyehouse that has affected both bulk to bulk and lab to bulk performance.

When a bulk dyeing is judged to be off-shade the dyer makes an addition of dye to the dyeing to correct the

colour. This correction step (known as a top up) adds on average 5 hours to the process and uses extra

water, energy and chemicals. This process has a lower negative impact than a complete re-dye (where the

fabric undergoes and complete new dyeing process to add the corrective dye) but still has a marked effect -

and a batch may need to be topped up more than once.

The figures for running bulk shades are shown below.


Fabric Bulk Batches 127 181 172 163 134 118 145 120 141

Fabric Bulk Batches RFT 116 163 165 151 119 103 129 113 124

Fabric Right First Time % 91 90 96 93 89 87 89 94 88

Yarn Bulk Batches 71 99 97 93 109 184 184 140 131

Yarn Bulk Batches RFT 63 88 88 80 95 171 175 104 99

Yarn Right First Time % 89 89 91 86 87 93 95 74 76

Total Bulk Batches 198 280 269 256 243 302 329 260 272

Total Bulk Batches RFT 179 251 253 231 214 274 304 217 223

Total Right First Time % 90 90 94 90 88 91 92 83 82

The bulk right first time figure was fairly steady at around 90% for both fabric and yarn dye until December

2009 (see later section on January and February 2010). One of the major reasons for the 10% failure rate is

that small sample dyeing machines are being used to dye bulk production.

The sample machines are not as well controlled and it is also difficult to get consistent liquor ratios in these

machines.

Dyehouse #1 are currently analysing the breakdown of failures from bulk and sample machines to

determine whether investment in extra bulk capacity is worthwhile.

90% is good but not world class. In order to get to 95% + they may need new equipment and may also

benefit from a move to blind dyeing for bulk running shades.

23

When a batch is complete the dyer checks the colour and makes an addition of dye if the batch is off-shade

- this checking procedure adds around 20 - 30 minutes to every single batch - even when there is no need

to make a correction.

Blind dyeing (the process where the dyeing is completed, unloaded and then checked) saves time on every

batch but it means the consequences of failure are large because fabric has to be reloaded and re-dyed

using a full process.

Increasing the consequences of failure therefore increases the pressure to get things right first time and

this generally has the result of improving performance.

January - February 2010

The bulk to bulk right first time performance of the yarn dyehouse deteriorated from an average of around

90% for the previous months to approximately 75% in January and February.

This equates to 1.5 failed batches per working day which does not seem like a major problem on a day to

day basis and it is only the data analysis that has highlighted the problem. The causes are now being

examined in detail - the problem appears to have affected both bulk to bulk performance and lab to bulk

performance in the yarn dyehouse but the performance of the fabric dyehouse has been good.

Although not good news at all for Dyehouse #1 it demonstrates the necessity of data collection to highlight

deviations from expected performance.


Dyehouse #1 are now recording the length of time for each individual and this shows that the time taken

for dyeing processes is a) longer than the pre-programmed time and b) significantly longer than industry

best practice times.


Average Process Time (fabric)* 10.48 10.84 10.08 10.2 10.26 10.75 10.7 10.8 10.7

Average Process Time (yarn)* 10.01 10.12 10.02 10.05 9.94 9.91 10.17 10.3 10.3

*Data analysis has indicated that the figures being recorded in the yarn dyehouse are all too low as they

have not added the time taken for top-ups to the initial process time. This was highlighted by the fact that

recorded average process times did not change significantly even though quality performance dropped

dramatically.

It is also apparent that the time taken for re-dyes is also not added to either yarn or fabric process times -

thus making average times for both fabric and yarn dye lower than they actually are. However the trend of

increasing process times in the fabric dyehouse is real and has enabled action to be taken.

These times are only for dyeing processes so are not affected by the level of white production.

An increase in the amount of viscose fabric being processed from November through to February has had a

negative effect on process times. The plan was to dye a premium product for a better price but the dyeing

machines are not ideal for viscose and therefore long, ultra-safe, methods were employed to avoid

customer dissatisfaction. However the data analysis has shown that cycle times and water and energy

24

consumption have increased dramatically and they are no longer taking orders for viscose until they can

produce them using cold pad batch dyeing.

Viscose should actually be processed in a shorter time than cotton (albeit using more water per bath) if

industry best practice methods are used and they have been advised to enlist the assistance of major dye

companies to advise.

They are now analysing the reasons for over-run vs programmed timings on a batch by batch as well as

looking at ways to fundamentally reduce the length of dyeing programmes.

In addition to average (mean) times Dyehouse #1 are looking at a more in-depth statistical analysis of

process times. For example the graph below for June 09 shows the most common process time is 9 hours

but ‘problem batches’, that take up to 31 hours, take the average up to 10 and a half hours.

In addition to reducing the number of ‘problem batches’ Dyehouse #1 are now also planning to introduce

shorter bleaching, dyeing and wash off methods with the aim of reducing the processing times by 20%. This

will reduce their energy costs and also increase their effective capacity.

Resource Utilisation

Daily Analysis

Full data allows for trend analysis to be conducted and this data has been instrumental in helping Dyehouse

#1 make the decision to move to a more controllable coal powered boiler.

The full data for boiler wood and electricity consumption vs total production volume for one month is

shown below.

The graph has had data from non-production days removed (where the ETP operates but no dyeing is

done).

25

It gives a figure for total electricity consumption (combining government units and generator units using a

conversion factor of 3.5 units per litre of diesel). The low points in the electricity graph are for the days

following a dyehouse shut-down - this is because less electricity is required in the ETP.

However the electricity low points are not always matched by boiler fuel low points and it is apparent that

boiler wood consumption is fairly level compared to the variations in production volume, (indicating lack of

ability to match steam output with dyehouse demand).

To be doubly sure that the boiler isn’t being modulated effectively it is wise to make an adjustment for the

level of white production.

As mentioned previously the amount of energy required to produce whites is about half that to dye an

average colour - the graph below therefore adjusts the production volume by halving the volume of white

per day in order to see if the electricity and boiler fuel consumption tracks total net production volume.

The graph below also adjusts the wood consumption to consider just that used for production in the

dyehouse (the ETP uses a fairly steady 13 tonnes per day)

26

This demonstrates that boiler fuel consumption isn’t well matched to net production volume and is the

basis for a move to a more controllable coal fired boiler.

Monthly Averages

The table below shows the trend of resource utilisation over the period July to December 2009 - the figures

for June are included but are from 6th June to 30th June only (i.e. incomplete)

Jun* July Aug Sept Oct Nov Dec

Tonnes of colour 99 133 128 124 127 112 139

Tonnes of white 84 103 84 113 89 85 100

Total production 183 236 212 237 216 197 239

Total diesel use 21789 20987 24154 25534 28437 28794 31200

Total govt units 166425 238476 210656 211800 196032 201704 212156

Total electricity units 242686 311930 295195 301169 295561 302483 321356

Electricity units / tonne 1326 1321 1392 1270 1368 1535 1344

Total water 2232 3419 3015 2981 3052 3299 2565

Water use l/kg 12.4 14.5 14.2 12.6 14.1 16.7 10.7

Total tonnes boiler fuel 643 832 762 781 747 724 759

Boiler fuel / tonne 3.5 3.5 3.6 3.3 3.5 3.7 3.2

It can be seen that the major factor on the efficiency of Dyehouse # 1 is the volume of business. When

volumes drop the amount of water, energy and boiler fuel used per tonne increases.

Throughout this period of time the dyehouse has operated for 6 days per week and the best way to reduce

impacts when production volume fall is to plan to complete the production in a shorter period of time and

then shut down machines and boilers.

Comparing July with December, where volumes and percentages of white vs coloured production are very

similar, it can be seen that water usage (-25%) and boiler fuel usage (- 10%).

The percentage of white production varied between 40% and 47% over the period and the impacts per

tonne are obviously less for months where white forms a larger proportion of the production.

January - February 2010


Tonnes of colour 99 133 128 124 127 112 139 109 128

Tonnes of white 84 103 84 113 89 85 100 71 77

Total production 183 236 212 237 216 197 239 180 205

Total diesel use (l) 21789 20987 24154 25534 28437 28794 31200 16974 9897

Total govt units 166425 238476 210656 211800 196032 201704 212156 254311 287643

Total electricity units 242686 311930 295195 301169 295561 302483 321356 313720 322282

Electricity units / tonne 1326 1321 1392 1270 1368 1535 1344 1742 1572

Total water 2232 3419 3015 2981 3052 3299 2565 3372 3486

Water use l/kg 12.4 14.5 14.2 12.6 14.1 16.7 10.7 18.7 17

Total tonnes boiler fuel 643 832 762 781 747 724 759 697 689

27

Boiler fuel / tonne 3.5 3.5 3.6 3.3 3.5 3.7 3.2 3.9 3.4

The general trend of improvement reversed in January 2010 as a result of an increase in viscose dyeing

production in the fabric dyehouse and reduced quality in the yarn dyehouse.

Production levels in January in February were relatively low but you can see that by comparing months

where production levels were similar (January vs June and February vs August) that the performance was

not due to overall production volume alone - the data allows you to look at historical trends.

At this stage it is not possible to separate out the impacts of poor quality in the yarn dyehouse and longer

viscose processes in the fabric dyehouse but the key point is that the detailed data analysis has highlighted

two issues that could have put the dyehouse out of business if left unchecked.

Salt

Dyehouse #1 has an on-site water and salt recycling facility.

Dyehouse #1 are now deliberately using approximately 5% less salt for each shade in the dyehouse but this

figure is not apparent from the figures below. This is because the total (gross) amount of salt used in

processing is actually governed by the colours required by customers (darker shades need more salt).

However Dyehouse #1 are now making using a greater proportion of recycled salt and this has led to a

drastic reduction of the amount of fresh salt being used.


Tonnes of colour 99 133 128 124 127 112 139 109 128

Fresh Salt (kg) 11295 14640 8203 6525 5910 4315 4845 3792 3026

Total Salt (kg) 31020 40384 41973 44185 40095 43000 45025 31087 32914

Kgs / Tonne Production 313 304 328 356 316 384 324 285 257

Kgs Fresh Salt / Tonne 114 110 64 53 47 39 35 35 24

Reduction of environmental impacts and cost savings

The following table gives a summary of overall annual resource usage and costs. The annual figures and

savings have been calculated using the data provided from June to December 2009.

The exchange rates used for the calculations are as follows:

1 GBP = 69 Rupee

1 USD =46 Rupee

1 Euro =63 Rupee

Dyehouse # 1

Annual Production (Tonnes) 2,674

Cost of Boiler Wood (R/Tonne) 3,000

Annual Consumption (Tonnes) 9,210

28

Annual boiler wood cost (R) 27,630,000

Cost of Diesel (R/l) 35

Annual consumption (Litres) 318,212

Annual diesel cost (R) 11,137,420

Cost of Electricity R/unit 5

Annual Govt Electricity 2,541,648

Annual cost of Govt Electricity 12,708,240

Total Annual Electricity Units 3,655,390

Total Annual Electricity Cost (R) 23,845,660

Cost of Fresh Water (R / m3) 25

Annual consumption (m3) 36,662

Annual water cost (R) 916,550

Annual Effluent volume (m3) n/a

Annual Dyebath Effluent cost (R) n/a

Dyehouse #1 has no cost for external effluent treatment since they are a zero discharge unit but they have

extra boiler fuel and electricity costs associated with running their ETP.

The following gives a picture of how resources are used in Dyehouse #1 when operating at capacity - the

purpose is to give an accurate estimation of the savings that various efficiencies will deliver.

Boiler Fuel Electricity Water

Dyeing 25% 38%* 100%

Finishing 25% 35% 0

Effluent Treatment 50% 27% 0

For example an initiative that saves 20% of the fuel consumption in the effluent treatment will have an

overall effect of saving 10% of boiler fuel consumption since the ETP only accounts for 50%

*The figure for electricity use is much higher than indicated in a previous report - this is because the figure

for yarn dyeing is now included. Despite accounting for only approximately 20% of the production volume

the yarn dyeing machines’ pumps operate under very high pressure and consume a huge amount of

electricity.

The detail of the savings generated by the following initiatives are provided in the appendix:

Improving Lab to bulk reproducibility from 75%-90%

Reducing cycle times by 20%

Moving from a wood powered boiler to a coal powered boiler

Introducing a 3rd Reverse Osmosis module in the ETP

Introducing Cold Pad Batch dyeing

29

Some of these items require significant capital outlay but others are free - but to give an indication of what

can be achieved for little or no investment a combination of quality improvements, process optimisation

and introduction of a 3rd RO module will save Dyehouse #1 20% of its costs (approx $200,000), 2500 tonnes

of wood, half a million units of electricity and over 8000 m3 of water per annum - for a single investment of

$28,000.

The bigger capital outlay items that they now have in the pipeline can only be fully judged when the new

increased production capacity is known - however it is anticipated that the benefits will be much greater

than those highlighted above.

Dyehouse # 2

This is a busy commission dyer based in Tirupur who can dye up to 11 tonnes per day of weft knit cotton.

They have good quality machines and use a mixture of high quality European dyes and some from local

manufacturers.

Dyehouse #2 have a good attitude towards improvement and have carried out a lot of actions that will

improve their performance and efficiency.

However their data collection has been poor, and unreliable, so it is difficult to confidently quantify the

effect of their quality improvements and machinery upgrades has had on the reduction of water, energy

and chemical usage.

At the commencement of the project their (balanced) effluent was treated at an off-site CETP but they had

plans in place to move to a communal ETP that was operated by themselves and two other dyehouses in

order to reduce the cost of effluent treatment.

At the beginning of 2010 Dyehouse #2 had to suspend production for two months because of the closure of

the CETP that previously handled their effluent - Dyehouse #2 re-started at the end of February 2010 with a

reduced capacity and at the close of the project they were capped at 4.5 tonnes per day whilst their

effluent treatment plant became fully operational (it takes several weeks for the population of bacteria in a

biological effluent treatment plant to grow and become fully established).

The temporary dyehouse closure was no fault of Dyehouse #2 and it is unfortunate that they lost business

because of the closure of the CETP.

However they will ultimately emerge from the process with a lower cost operation and a lower

environmental impact process.

A relatively small dyehouse (by global standards) like Dyehouse #2 is still likely to use approximately 550

tonnes of salt each year so the move to zero discharge prevents this huge amount of salt being placed into

the local environment.

Dyehouse #2 used the time during the factory closure to implement some of the recommended process

changes and also make some upgrades to equipment which has resulted in the performance being much

better than prior to the closure.

They are also beginning to collect some data which will enable them to target areas for improvement.

30

Their full action plan is shown below but a summary of their key improvements is as follows:-

They have put measures and ‘checkpoints’ in place to get more consistent bulk processing including

control of liquor ratios, salt concentrations, pH and measurement of post-bleach whiteness levels.

Since introducing all these checks they report that ‘all bulk batches have been OK’ with no failures -

whilst a claim of 100% right first time may seem a little optimistic there is no doubting they have

improved drastically - and now even admit to pre-closure levels of 70% for bulk to bulk right first

time

Having started to gather process data the most striking feature was that their right first time

performance for new colours was significantly worse than they originally thought. They originally

said that 20% of first bulk batches required corrections and it is now apparent that the figure is

closer to 50%. Commission dyers can have up to 50% of their production made up of new shades at

certain times of the year so this single piece of information could provided them with the

opportunity to improve their performance and environmental impacts considerably.

They have identified that a single faulty laboratory dyeing machine was the biggest single cause of

their problems. Since taking it out of commission and applying the bulk ‘checkpoints’ to the first

bulk dyeings they have improved to 80% right first time.

Rather than improving a completely unsatisfactory dye and chemical storage and weighing area

they built a new one - should be operational in mid 2010.

New mangle rollers have been installed and have been operational since the factory re-start. In

theory this will dramatically reduce the electricity and fuel bills for fabric drying.

AC drives have been installed on several pieces of equipment including dryers to reduce

consumption of electricity

The dyehouse central controller has been repaired and re-programmed and has reduced dye cycle

times by ‘on average one hour’

The automatic chemical dispensing system repaired and is now operational

Dyehouse #2 have started to examine the possibility of Cold Pad Batch dyeing as part of a plan to

increase their dyeing capacity. This is probably the single most beneficial this they can do to reduce

their costs and environmental impacts. It is an inherently lower cost and lower impact process than

jet dyeing but, being a salt-free process, it is doubly beneficial in a zero discharge situation since

effluent can be recycled by the use of reverse osmosis alone rather than the need to use expensive

and energy intensive evaporators to remove salt.

£ Basics and Minimum Standards

Ensure all operatives wear appropriate personal protective equipment (gloves, goggles, shoes)

Nothing actioned

Free

Ensure all dispensed chemicals, ready for use in a dyeing, are labelled

Nothing actioned

Free

31

Improve storage and housekeeping in the dye and chemical weighing area

Major building work in progress to create improved dye and chemical storage facility

Free

Consider creating a cooled/conditioned environment for dye storage and weighing area £

Quality START TO COLLECT ALL INPUT, OUTPUT AND QUALITY INFORMATION ON SPREADSHEETS PROVIDED

Some data collection started in November - data on bulk dyeings, water, diesel, electricity and wood consumed per day still outstanding Free

Introduce specific gravity checks to confirm salt levels

S.G. Checks now in place and enabling more consistent liquor ratios. Also implemented pH and whiteness checks Free

Improve standardisation of bulk liquor ratios

Free

Always re-check lab dyes if standard liquor ratio cannot be used in bulk processing

Done

Free

Introduce a batch card for use in the dyehouse, onto which operatives record all process details

New batch card being printed

Free

Check the strength of incoming dye deliveries via lab dye checks

Nothing auctioned - may not be required if bulk RFT of 100% is maintained! Free

Create continuity cards so that batch to batch variations can be easily compared. Include details of right first time / additions/ top ups and DE read-outs on the continuity cards.

Nothing auctioned - needs to be addressed

Free

Take a sample after bleaching and measure whiteness to establish consistency of preparation.

Done - whiteness levels recorded on batch cards

Free

Use EDP's to make additions to lab dyes rather than inaccurate syringes

Now happy that syringes are sufficiently accurate £

Create a single record card for all lab dye information (to augment / replace current system of multiple cards for different aspects of lab dyeing process

Nothing actioned

Free


Do not want to jeopardise relations with customer. Will fully support educational seminar for brands and garment makers

Free


Still done visually except where there is a problem

Free

Introduce a standardised regime for colour measurement for bulk samples - along the same lines as the lab processes. They should be washed off in the same manner, neutralised, dried and conditioned before measurement.

Nothing actioned

Free

32

Always use the original master standard when judging bulk batches. Even if a secondary standard has been created (to account for compacting) the use of the original master shade will reduce the chance of drifting away from what the customer specified

Now being used

Free

Create a team of dyehouse and laboratory staff to conduct failure analysis for all batches at are not right first time

Lab manager conducts failure analysis

Free

Conduct failure trend analysis to see if particular shades, dye combinations, machines, operatives are a problem and to analyse if problems are hue or depth problems are the major cause of failure.

Free

Repair automated chemical dispensing system

Repaired and in use £

Repair central dyehouse controller Repaired and re-programmed £

Make adjustments to account for weight losses in preparation, scouring and biopolishing

Free


Evaluate salt-at start dyeing techniques (enables s.g. Measurement - but must consider additional volume of liquid introduced with dye and alkali)

Done for dark shades

Free

Look at using reduced salt levels in all dyeings to a) reduce salt consumption b)improve level dyeing and c)provide an opportunity for reducing wash off processes. Do not alter any running bulk shades without thorough laboratory trials.

Lab checks have indicated 'unacceptable' loss in depth but dyehouse #2 do use lower salt levels than most dyers

Free


Nothing actioned

Free

Evaluate the possibility of re-using the final wash off bath in subsequent dyeings (this contains so little dye as to be insignificant compared to the first post-dye wash off bath and so can be used with little risk)

Long term aspiration

£

Evaluate the possibility of re-using the post-bleaching wash off bath for post-dye washing

Long term aspiration

£

Reduce in-bath fabric sampling to one after bleaching and one after dyeing and wash off.

Done

Free

Rigorously monitor process times and the % of time taken in sampling and for decision making - consider moving to blind dyeing for certain shades

Nothing actioned

Free

33

Factory Planning


Do not want to jeopardise relations with customer. Will fully support educational seminar for brands and garment makers

Free


Estimates now available

Free

Monitor fuelling of boilers and whether this can be further optimised to match heat and steam requirements

Will assess ability to match boiler output with dyehouse demand

Free


Investments


Will cost and establish cost / benefit

£


Have decided to not pursue this. Auto dispenser better for dyes and satisfied with syringes for alkali additions £

Consider replacing mangle rollers to reduce moisture content of fabrics proir to drying - pay back in less than 12 months

Installed and will operate on factory re-start

£


Finally clarity was obtained - they have a system for monitoring exhaust gases for moisture and control the machine using this - not as good as a fabric moisture meter but better than nothing £

Look at using /repairing moisture meters on the stenter to prevent over-drying. Even if these are shown to temporarily mark the fabric it is a useful exercise to see if the current conditions are over-drying certain fabrics. Work with garment makers to see if marks are permanent - they are unlikely to be visible on final garments.

See above

£


low priority

£

Conduct cost-benefit analysis of introduction of AC drives throughout the factory (major benefit will be on the on dryer blowers

AC drives for dryers now installed

£

New high speed multi-pass stenter being considered

Colour Connections do not know of its use elsewhere £

New Technology


To run trials with Huntsman in April

Free


To run trials with CHT on factory re-start

Free

Infrastructure Conduct cost-benefit analysis of heat recovery from stenter and dryers

Will carry out initial investigations

£

Data Analysis

34

Only limited data has been provided so it is difficult to present the information in any conclusive form

despite the excellent progress with certain action points.

Quality Performance

The original estimate of 80% lab to bulk right first time, provided at the start of the project was proven to

be very optimistic.

Nov Dec

Fabric 1st Bulk Batches 131 126

Fabric 1st Bulk Batches RFT 66 70

Fabric Right First Time % 50 56

The reality was that the lab to bulk right first time performance was much less than the estimated figure

and had to be addressed to improve performance. Commission dyers have a disproportionately high

number of first bulk batches compared to vertical organisations so lab to bulk right first time has a

disproportionately high impact on overall factory performance.

Detailed failure analysis highlighted that the main cause of the failures was a faulty laboratory dyeing

machine and by taking this out of commission they have achieved 80% right first time on the small number

of 1st bulk batches that have been produced sine the factory re-start - the figure of 80% is credible and has

been verified by Colour Connections.

The has been some anecdotal evidence to suggest that bulk performance had improved prior to the factory

closure, largely due to improved management of lot sizes, salt concentration and liquor ratio but data

wasn’t available to confirm this.

However since the factory re-start they have definitely been taking greater care over bulk dyeings and have

introduced ‘checkpoints’ including the measurement of salt concentration, pH, and whiteness of fabric

after bleaching and data does indicate a remarkable, if unsustainable, figure of 100% right first time on the

small number of batches that have been produced since the re-start.

It was concerning that the reason for 100% rft was given as ‘we can keep out eyes on everything all the

time when volumes are low’. On one hand it proves what they are capable of, but on the other there seems

to be an acceptance that things will get worse when they get busy. The importance of demanding

checkpoint data and ensuring processes are carried out in line with standard operating procedures has

been emphasised.


No consolidated data provided but they claim that process times have reduced to an average of 8 hours

from 9 hours as a result of the use of the repaired central dyehouse controller with new shortened

programmes - this is very plausible and appeared to be the case during the last project visit.


35

Some actions taken by Dyehouse #2 will certainly reduce the overall environmental impacts (such as new

mangle rollers and the introduction of AC Drives) compared to the start of the project but no data is

available to confirm the extent of the improvement.

The estimates of daily resources utilisation that were provided at the start of the project are in the table

below along with monthly figures provided for the post-re-start period where production volumes were

capped.

Current Daily Production Volume (tonnes) 10

Daily wood consumption (tonnes) 37.5*

Wood consumption / tonne of fabric 3.75

Daily diesel consumption (litres) 650

Diesel consumption / tonne of fabric 65

Daily electricity consumption (units) 6480

Electricity consumption, units / tonne of fabric 648

Daily water consumption (m3) 600

Water consumption, m3 / tonne of fabric 60

Monthly figures:

Jun 09 Mar 10 Production Volume (tonnes) 240 108 Wood consumption (tonnes) 900 552

Wood consumption / tonne of fabric 3.75 5.11 Diesel consumption (litres) 15600 1920 Electricity consumption (units) 155520 144000 Total Electricity units 210120 150720

Electricity consumption, units / tonne of fabric 875 1396 Water consumption (m3) 14400 7200

Water consumption, m3 / tonne of fabric 60 67

*Previous reports have carried a figure of 15 tonnes of wood used per day. It is now clear that the figure

was for boiler wood only and that a further 22.5 tonnes (estimated) would have been required to heat the

dryers and stenters (Dyehouse #2 report that 60% of wood is used for the finishing department).

The figures provided for the factory post-start up can be treated as no more than estimates, and since the

production volume is less than half that in June it is not surprising that more wood fuel and electricity is

used per tonne.

However if the figures are even vaguely credible it does indicate that the water consumption is impressive -

particularly compared to Dyehouse #3.

In future when their ETP is working they will be consuming much less water (net) because they will be

recycling water.


36

Dyehouse #2 report that they have the following breakdown of water, wood and electricity consumption in

their dyehouse:


Dyeing 40% 40% 100%

Finishing 60% 60% 0

Their quoted usage and unit costs for the pre-shut down situation are in the following table and these

figures have been used to calculate savings from the initiatives they have put in place.

Dyehouse # 2

Annual Production (Tonnes) 2880*


Annual Consumption (Tonnes) 10800






Annual Govt Electricity 1,866,240


Total Annual Electricity Units 2,521,440



Annual consumption (m3) 172,800

Annual water cost (R) 9,504,000

Annual Effluent volume (m3) 155520

Annual Dyebath Effluent cost (R) 12,441,600

The appendix contains estimates of the savings generated by the following initiatives that have already

been implemented - water and electricity savings will definitely be seen by the dyehouse although savings

on boiler fuel will only be realised if the boiler and thermic flue can be modulated:

Improving bulk to bulk from 75 - 90%

Improving Lab to bulk from 55 - 80%

Installing new mangle rollers to squeeze out more moisture

Installation of AC drives on dryer and stenter

As with Dyehouse #1 it shows that remarkable reductions of 20% of annual costs and environmental

impacts can be achieved for a relatively low investment.

37

In this case an investment of $80,000 leads to annual savings of approx $300,000 -achieved by saving 2200

tonnes of wood, 750,000 units of electricity, 12700 m2 of water which in turn leads to less effluent.

The savings in effluent treatment costs will now not be realised in terms of CETP fees but it will make their

own ETP cheaper to run.

The calculations for Dyehouse #2 will be slightly more complicated in the future because their new zero

discharge effluent treatment plant will be co-owned by three different dyehouses. The calculations in the

report are based on their present set up of off-site effluent treatment.

(NOTE: an example of how Dyehouse #2 justified investment in new mangle rollers was given in a previous interim

report and they based their calculations on 60% of boiler fuel and 70% of electricity being used for drying and finishing

but these figures have not been confirmed - it doesn’t alter the fact that investing in new mangles is a sensible move

but does slightly change the calculated payback time)

Dyehouse # 3

Dyehouse #3 is part of a vertical garment company and is based in the Sipcot development in Perundurai.

They are a small dyehouse with a capacity of 3 tonnes per day and at times during the project they were

operating at very low production volumes.

Effluent is sent to a SIPCOT based CETP for treatment and Dyehouse #3 pay a charge for this service.

They use good dyes, the dyeing machines are of a good standard and they are technically proficient.

Dyehouse #3 have a mix of simple, lower impact washing processes (pre-dyed striped fabrics that are

simply washed) and higher impact dyeing processes.

Of the selected factories Dyehouse #3 have implemented the least number of items from their action plan.

This is largely because their bulk to bulk reproducibility is so good (95%+) they do not want to do anything

that will jeopardise that performance - even though they recognise the merits of the actions.

Towards the end of the project they provided some good data dating back to November 2009 onwards that

enabled us to highlight to them their actual performance and which also allows them to quantify the

benefits of the proposed initiatives.

Some actions have been taken and the most beneficial are as follows:-

Data analysis has shown lab to bulk reproducibility is not as good as they thought. They are now

working with dye companies to introduce better dye combinations and are also improving their

internal processes and laboratory equipment.

Trials have now convinced the management that there is variation between the laboratory

technicians and they are looking to purchase more robust equipment. Difficult shades are now

being dyed with more appropriate dye recipes.

38

They are also seeking advice from the dye companies on shortening dyeing processes by removal of

unnecessary migration methods.

Failure analysis is now conducted to look at the reasons why batches have gone wrong.

The biggest issue for Dyehouse #3 during the project has been the cost of running the factory when

production volumes have been low. They are now taking steps to consolidate production and turn

off boilers and machines where possible to reduce fuel and electricity use per unit of production.

The detailed action plan that was drawn up for Dyehouse #3 is shown below.

Action Progress £ Basics and Minimum Standards

Ensure all operatives wear appropriate personal protective equipment (gloves, goggles, shoes)

Nothing changed but not a major problem anyway Free

Ensure all dispensed chemicals, ready for use in a dyeing, are labelled

Nothing changed but not a major problem anyway Free

Consider creating a cooled/conditioned environment for dye storage and weighing area

Non-critical suggestion, nothing actioned

£

Mend all leaking steam pipes Some fixed Free

Quality START TO COLLECT ALL INPUT, OUTPUT AND QUALITY INFORMATION ON SPREADSHEETS PROVIDED

Data collection has started - need some more detail Free

Introduce specific gravity checks to confirm salt levels in bulk dyeings

Now checked in critical shades Free

Calculate liquor carry-over from one bath to the next for different fabric qualities using s.g. checks and water meters to get accurate liquor ratio information

Nothing actioned

Free


Not prepared to upset customers despite illogical request! Free


Instrumental colour measurement being done on finished fabric - New Spectrophotometer in use

Free

Always use the original master standard when judging bulk batches. Even if a secondary standard has been created (to account for compacting) the use of the original master shade will reduce the chance of drifting away from what the customer specified

More data standards are being provided Still using secondary standard. Customers giving very small cuttings rather than good standards and qtx data files in most cases.

Create a team of dyehouse and laboratory staff to conduct failure analysis for all batches at are not right first time

Failure analysis being implemented

Free

Conduct failure trend analysis to see if particular shades, dye combinations, machines, operatives are a problem and to analyse if problems are hue or depth problems are the major cause of failure.

Data showing that lab to bulk RFT is major area for quality improvement - 66% is much worse than verbally quoted figure at the start of the project

Free

39

Introduce consistent method for conditioning samples prior to colour measurement

Not done Free


Look at using reduced salt levels in all dyeings to a) reduce salt consumption b)improve level dyeing and c)provide an oportunity for reducing wash off processes. Reducing salt by 10 or 20% may result in a drop in depth of shade of 1 or 2 % in some instances but does offer the opportunity to reduce wash off procedures considerably. Currently using 15-20% more salt than other dyehouses in the region for similar shades.Do not alter any running bulk shades without thorough laboratory trials.

Lab trials have shown reduced salt level to yield reduced depth of colour. However need to re-examine this using mixed alkali package

Free


Not Done

Free

Trichromats are currently dyed with Remazol RGB shades. This is not a recommended combination - consider moving to Levafix CA or Itofix VM ( probably the most robust trichromat available) to improve reliability and levelness

Meetings held with DyStar and Huntsman to look at all dye combinations, salt and alkali recommendations and processing methods. New dye recipes now being used for difficult shades.

Free

Examine all shades currently dyed using migration methods and consider which can easily be moved to shorter and cheaper isothermal processes.

Free

Used mixed alkali systems to fix dark shades. Higher levels of fixation will allow shorter wash off procedures.

Free

Rigorously monitor process times and the % of time taken in sampling and for decision making.

Data collection started Nov 1st Free

Factory Planning /

Management Systems


Reluctant to do anything to jeopardise customer relationship

Free


Data not yet available - estimates only Free

Monitor fueling of boilers and whether this can be further optimised to match heat and steam requirements

Data not yet available

Free

Monitor and report sample volumes produced compared to bulk production and consider setting an in-house limit

Done

Free

Consider partial wash-off of samples and issuing disclaimer to customers saying sample is for colour only (to save on water and energy used in sampling)

Samples dyed on bulk bleached fabric to shorten processes

Free

When production volume is low consider taking on commission work to improve per unit costs and environmental impacts

Not part of company policy

Free

40

When production volume is low consider reducing working time of factory to less than 6 days per week. Sending workers home on full pay is much cheaper than inefficient operation of the factory

Factory planning now higher priority when production volumes are low.

Free


Investments


Deemed too expensive

£


Evaluating Mettler and Toledo £


Quotes ‘due from Monforts’ - original request was allegedly made in September £


£

Consider pin-entry for relax dryer to remove the need to double passes on certain heavy fabrics.

Quotes due from Bianco. Double pass now replaced by single slow speed pass. £

New Technology


Meeting to be arranged.

Free


Meeting to be arranged.

Free

Infrastructure Conduct cost-benefit analysis of heat recovery from and dryers (Koenig suggested)

In discussion with Forbes Marshall, who have carried out some on-site surveys £

Hot water system - planned In-house project still not started £

Data Analysis

Dyehouse #3 have provided data for November, December and January.

They have three types of production:

Whites

Coloured dyeings

Washing of yarn dye stripes

Full information on the split between whites and coloured production is not available but information on

the amount of washing vs dyeing is provided.

The data needs to be handled carefully as results will vary from month to month depending on the

production mix (for example in both November and January 60% of batches were dyed and 40% were

washed, but in December 73% of batches were dyed).

Quality Performance

41

The figures below are for November 2009 to January 2010 inclusive and are for coloured dyeings only. No

information was made available for January onwards.

Nov - Jan

Fabric 1st Bulk Batches 32

Fabric 1st Bulk Batches RFT 21

Fabric Right First Time % 66

This figure is significantly lower than they indicated at the start of the project - Dyehouse #3 now taken the

sensible step of moving to industry best practice dye recipes to address the problem and have reported an

improvement ‘to about 80%’ - although no data was available to confirm this.

The bulk to bulk performance is exceptionally good and can be rated at world class - but the reluctance to

do anything that may risk a drop in this figure is holding Dyehouse #3 back and they are in danger of going

out of business due to high costs.

Nov - Jan

Fabric Bulk Batches 203

Fabric Bulk Batches RFT 195

Bulk Right First Time 96


The average process time is 10.89 hours which is much longer than industry best practice.

Reducing cycle times provides Dyehouse #3 with a major opportunity for improvement and they are to

examine shorter dyeing process, lower impact bleaching and shorter wash off processes.

Dyehouse #3 are certainly good enough to move to blind dyeing (96% right first time is world class) and the

removal of checks at the end of dyeing would save them time.


Daily analysis of electricity and boiler fuel consumption in relation to production volumes is not possible

because daily production data is not available.

However it is possible to look at the relationship between electricity consumption and boiler fuel

consumption over the period of November 2009 to January 2010.

Dyehouse # 3 have had low production volumes over the period of the project and encouragingly they do

now try to plan production so that the boiler and machines can be switched off on days when there is no

production - resulting in lower energy consumption.

The graph below shows that in contrast to Dyehouse #1 the amount of boiler fuel used each day does vary

significantly. This suggests that they are able to modulate steam output to match dyehouse steam demand

- although it will need to be viewed against daily production volumes to confirm this.

42

Electricity consumption is more consistent, particularly in December and January (number 31 onwards on

the horizontal axis), indicating that they will need to monitor whether high consumption machines are

being left switched on all day even when production volumes vary - again this will need to be viewed

alongside daily production volumes to confirm this.

Monthly Averages

Jun* Nov Dec Jan

Tonnes of colours + white 25 51 42

Tonnes of washing 15 17 30

Total production ~50 40 68 72

Total diesel use 1840 7804 3450

Total govt units 49237 81484 66054

Total electricity units 55677 108798 78129

Electricity units / tonne 1462 1391 1600 1085

Total water 4439 6835 6522

Water use l/kg 60 111 100 91**

Total tonnes boiler fuel 170 283 234

Boiler fuel / tonne 5 4.3 4.2 3.3

*Figures for June were estimations only

**The water consumption is probably even higher than the figures given in the table. Up to 115 litres per

Kg are taken into the factory and explanations that around 15% of incoming water ‘is low grade water for

watering plants only’ lack credibility.

The reduction in water and boiler fuel usage per tonne looks impressive but this is largely because of the

increasing production volume between November and December and also a greater proportion of

(relatively low impact) washing work in January compared to December.

Detailed data on the comparative energy and water use of coloured dyeings, white dyeings and washing

processes are required to make it possible to confirm there is a genuine underlying improvement in

resource utilisation.

The most obvious figure here is that Dyehouse #3 uses approximately 100 litres of water per kg of

production - a lot more than their estimate of 60 l/kg at the start of the project.

43


Dyehouse #3 have not been able to provide data to firmly establish the breakdown of resource utilisation in

the different areas of the factory but their estimate is as follows:


Dyeing 50% 50% 100%

Finishing 50% 50% 0

The annual usage of resources and cost is shown in the table below:

Dyehouse # 3

Annual Production (Tonnes) 724


Annual Consumption (Tonnes) 2,748






Annual Govt Electricity 787,100


Total Annual Electricity Units 970,416



Annual consumption (m3) 83260

Annual water cost (R) 3,330,400

Annual Effluent volume (m3) 59980

Annual Dyebath Effluent cost (R) 9,596,796

The potential savings for the initiatives that have been discussed with Dyehouse #3 are contained in the

appendix.

Consolidation of work into 5 days

Improvement of lab to bulk reproducibility from 65 to 80%

Reducing cycle times by 20%

Finding water ‘losses’ and reducing consumption by 20% (The dyehouse manager is insistent that

dyeing processes use less water than they are consuming/paying for so water losses need to be

accounted for).

44

At this stage it is not possible to verify whether any savings have been delivered despite assertions that lab

to bulk reproducibility has been improved and indications that greater efforts have been made to

consolidate production into fewer days.

However the data shows that Dyehouse could reduce their costs and environmental impacts by up to 30%

without any capital investment. The majority of the savings will be achieved by reducing cycle times and

simply planning the production more efficiently.

3. EcoMetrics

EcoMetrics (www.colour-connections.com/EcoMetrics) is a tool developed by Colour Connections to

qualitatively assess products and processes in terms of water, energy, use of chemicals and pollution.

It considers the whole life cycle of a product from fibre production through to disposal but it can be applied

to examine specific processes such as dyeing in more detail.

High negative environmental impacts are given a high score and denoted by red flags and and low

environmental impacts are given a low score and denoted by green flags - each part of the process is

assessed in terms of water, energy, chemicals and pollution and a total score is calculated. A bright pink

colour is used to indicate scores/impacts that are significantly worse than industry average.

The EcoMetrics principles have been used throughout the Eco Efficiency project and there has been a

balanced assessment of each of the four key factors (rather than, say, focusing just on carbon emissions).

Tirupur is a great example of where a balanced approach, promoted by EcoMetrics, has been important in

reducing the environmental impacts. Had the focus been on CO2 emissions rather than on pollution the

move to zero discharge would not have been made. The move to Zero discharge has almost eliminated

water pollution, drastically reduced net use of water for dyeing in the region (because of enforced

recycling), reduced chemical consumption (because of forced recycling of salt) but has necessitated the use

of more fuel and electricity to power the zero discharge plants.

The principles of EcoMetrics have been applied to the project rather than a rigorous scoring system but a

qualitative indication of how the selected dyehouses compare to industry average is shown below.

The EcoMetrics tool can assess a whole production process but in this case we have focussed on a

combined snapshot for the dyeing process.

The approach gives a qualitative snapshot of the performance in terms of:

Water impact

Energy

Use of non-renewables (other than for energy production)

Pollution

The industry average profile for reactive dyeing process of weft knitted cotton in jet dyeing machines is

based on a total water consumption of 100 – 120 litres of water per kg, 8 -12 hour dyeing cycles and

effluent treatment followed by discharge into a receiving waterway.

http://www.colour-connections.com/EcoMetrics

45

It looks like this:

Water Energy Use of non-renewables Pollution

Lots of water is used and therefore lots of energy has to be used to heat the water and run the machines

for prolonged periods of time. Lots of chemicals have to be used for scouring and bleaching, and lots of dye

is applied using lots of salt. Even though effluent treatment is carried out there is still a significant amount

of chemicals that enter the environment as a result of the process.

The following section gives a visual indication of how good and bad the dyehouses the selected dyehouses

are compared to industry average.

Dyehouse # 1


The water impact is very low as the net usage is less than 10 litres per kg. Salt is re-cycled and, being a zero

discharge dyehouse, no pollution leaves the site, except from the boiler stacks and generators. The

downside is that the energy consumption is very high because of the need to power the dyehouse and the

ETP and evaporators. The high quality, good factory efficiency and low water consumption keeps energy

usage in line with ‘average’ dyehouses.

As demonstrated in the project their key objective is to reduce energy consumption and to achieve this

they do have to consider their gross water consumption.

When Cold Pad Batch dyeing is introduced alongside the jet dyeing they will reduce gross water and energy

consumption and their profile is likely to reach the following excellent situation.


Dyehouse # 2

46


The water consumption figures at the start of the project were much better than the industry average but it

has been established that energy consumption was quite poor (after the latest boiler fuel figures became

available). The use of non-renewables was in line with industry average but since it has been established

that the CETP they were using was NOT zero discharge the impact was high. (The amount of effluent was

the same as say a European dyehouse but the impact is much higher in Tirupur because of the existing

problems and lack of dilution).

The move to their own zero discharge facility will drastically improve their net water usage and use of non

renewables (they will use recycled water and salt from the ETP) and they will no longer have a pollution

issue.

However they will use even more energy per tonne of production (required to run the ETP) and they will

have to constantly strive to reduce energy consumption. They are likely to achieve the following:


If they do go ahead and introduce cold pad batch dyeing (currently being examined) they can improve

towards the performance of Dyehouse #1 although will need to work very hard to achieve an orange rating

for energy.

Dyehouse # 3


The water usage originally quoted at the start of the project was much better than industry average but it

became clear that they were under-estimating the amount they use. Because a relatively large dyehouse is

being used to dye a relatively small amount of production, the energy consumption is enormous.

47

It became clear during the project that the CETP used by Dyehouse #3 was genuinely zero discharge but

they do not use any recycled salt and the use of recycled water is very low.

By improving production planning, reducing water consumption and reducing cycle times they will be able

to achieve the following:


This is not as good as the other two dyehouses but is still much better than the industry average. Ultimately

they could potentially obtain a green rating for water if they used more recycled water in their processing.

4. Key Best Practice

The following is a summary of the best practice developed for the dyehouses in this project. Some of the

best practice is only applicable to jet dyeing of cotton (indicated by [co] but most is universally applicable to

all dyehouses.

Quality

Systems to collect and analyse quality data are essential for determining factory performance and

identifying opportunities for improvement. Key measures that should be put in place are:-

o % Lab to bulk right first time

o % Bulk to bulk right first time

o %Re-finish

o Actual dye process times vs programmed process times

o Machine utilisation

o Resource utilisation

Electricity per unit of production

Boiler / Heating fuel per unit of production

Water consumption per unit of production

Chemical consumption per unit of production

Effluent cost/volume per unit of production

Set up a team to conduct failure analysis to highlight the reasons why things have gone wrong

Ensure batch cards are designed to collect maximum amount of process data and that operatives

sign cards to confirm processes have been carried out correctly

Ensure production is managed to give a consistent liquor ratio in dyeing

[co] Ensure salt levels in dyeings are measured, controlled (and reproduced in laboratory dyeings)

Use high quality, tightly standardised dyes

Use the best dye weighing and dispensing equipment you can afford

48

Use sophisticated machine controllers to ensure process consistency and to automatically record

deviations from set programmes

Ensure product examination and testing is carried out in-house and that results are used as data for

continuous improvement programmes

Never confuse a commercial decision with a technical decision - ensure all right first time data is

based on a ‘pass’ against a set standard

Dyeing Process Optimisation

Ensure process time is a business Key Performance Indicator

Use machine controllers to develop shortest possible dyeing programmes

o Use pre-heated hot water to save time on heating

o Use ‘parallel’ functions rather than sequential functions wherever possible to shorten time

o Use combined cooling and rinsing (CCR) type rinsing programmes to save time but ensure

water use is carefully managed

[co] Reduce the amount of salt in dyeings to allow easier dye wash off with less water

[co] Do not use migration methods unless absolutely necessary for the most difficult shades

Evaluate current wash off processes to see if any baths can be removed without compromising

quality

Review dyeing methods and reduce ‘over-safe’ dosing times and unnecessary holding times

[co] Reduce unnecessary fabric checks and sampling but ensure pH and salt checks are retained

Factory Planning / Systems

Conduct machine utilisation studies to calculate the portion of time machines are actually

processing production

Consolidate production and switch off machines and infrastructure (boilers, generators,

compressors) when not in use

Develop factory processes based on objective colour management and the dyehouse ability to

match a data standard and make objective pass/fail judgements

o Do not keep fabric in a wet state whilst QC subjective decisions are made by customers

Machinery Upgrades and Hardware

Install machines controllers, or better still central controllers to ensure process consistency and

recording of process data

Invest in high speed hydroextractors and harder mangle rollers to improve removal of water prior

to final drying

Replace DC drives on motors, pumps and blowers with more efficient AC drives

Insulate machines to reduce heat losses

New Technology

[co] Evaluate enzyme bleaching technology to save energy

[co] Evaluate in-salt detergent technology to reduce time, water and energy used in reactive dye

wash off

[co] Evaluate the use of continuous bleaching and counter-flow wash off to reduce time, water and

energy used in reactive dye wash off

49

[co] Consider cold pad batch dyeing for knitted cotton fabrics to reduce time, water, energy and

chemicals used in dyeing AND to remove salt from effluent

Infrastructure

Select boilers that can be modulated to match steam demand

Recycle steam condensate

Recover heat from effluent and from dryers and stenters

Develop a hot water system to save on heating time and to provide heat sink for re-cycled heat

Consider co-generation

Consider renewable energy sources

Consider full or partial recycling of water

5. Best Practice Seminars

Best practice seminars were held in three locations to share best practice with the wider Indian dyeing

industry.

Colour Connections enlisted the assistance of the Society of Dyers and Colourists to help with local

arrangements a selection of world renowned organisations presented best practice lectures to address the

specific opportunities highlighted by the project.

Each seminar had a cap of 100 pre-registered delegates.

Tirupur 24th March 2010

Demand was exceptional and locals described the event as the best ever held there and said delegate

numbers were ‘unprecedented’. The project focussed on processes for weft knit cotton and since the

majority of the audience were from that industry both the specific and general content was relevant to

them - the venue had to be closed when 153 delegates had entered the conference! 40 more unregistered

delegates had to be turned away for safety reasons.

Mumbai 25th March 2010

The Mumbai seminar also attracted over 100 delegates on the day but the number was not as great as at

Tirupur and the venue coped easily.

Unlike Tirupur, where they only produce weft knit cotton, there is a mix of different industries in the

region. Some of the specific references to weft knit cotton would not have been directly relevant to all

delegates but most of the best practice from the project is still applicable to any dyeing operation and

delegates stated that they were highly satisfied with the content.

Jodhpur 26th March 2010

The industry in Jodhpur is basic and in need of significant improvement. On one hand it was the perfect

place to hold a best practice seminar as the industry is in dire need of expert advice. However some

delegates’ existing level of knowledge was so low that some of the seminar content was aspirational.

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An audience of over 90 delegates was judged once again to be ‘unprecedented’. Credit must go to the

Society of Dyers and Colourists who have identified this area as being in need of improvement and who

lobbied Colour Connections to run one of the seminars in this region rather than in more developed areas.

The support of retail brands was genuinely beneficial to the project but if future dyehouse projects do take

place the Jodhpur is probably a better candidate than Tirupur. Most dyehouses have no concept of

efficiency because water is free (although incredibly scarce) and they discharge untreated effluent into the

rivers.

There is no way large brands would want to be associated with this sort of dyehouse but there is need to

improve to reverse the environmental damage that is occurring.

6. Key Findings of the Project

There is potential to make very large reductions in the environmental impact of dyehouses by

implementation of best practice.

The biggest challenge is getting dyehouse staff engaged and motivated to improve when they are

busy with day to day production issues.

o The inability of factory staff to allocate sufficient time to improvement projects is the major

hurdle to improving the dyeing industry.

Data collection is very, very important. In good dyehouses it is very difficult to identify areas that

require improvement without data and opportunities for improvement can be lost.

It is possible to significantly reduce costs and environmental impacts by simple, low cost actions but

in order to maximise progress some capital investment is necessary.

Even though some progress has been made with the selected dyehouses and steps taken to deliver

further benefits in the coming months the time allowed for an industrial project with working

factories was not enough (June 2009 to March 2010)

7. Recommendations for modifications if Eco-efficiency project is run in other Countries

Allow more time.

Choose poorer dyehouses - representative of the industry average and below. Brand support would

be difficult because do not want to be publicly associated with poorer dyehouses.

Engage factory owners at the outset.

o Eco-efficiency projects are dyehouse profitability projects! The owners will get the main

financial benefits whereas the factory managers get no extra money whilst being expected

to do the projects in addition to their day job.

Include an on-site expert project (such as MentorSys from Intertrad, www.intertradgroup.com )

with permanent on-site project teams in addition to the consultancy approach.

Next Steps

Each dyehouse will be provided with an action plan to work on after the completion of the Defra project.

http://www.intertradgroup.com/

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8. Appendix

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The appendix is contained in a separate document and contains the details of the following:-

1. Dyehouse screening reports

2. Data collection templates

3. Calculations for savings for dyehouse initiatives

Phil Patterson Managing Director +44 (0)7799 656786

www.colour-connections.com

Colour Connections Consultancy Ltd is a private limited company, registered in England & Wales 10th Sept 2007, no. 6366020, registered office

141-145 Dale Road, Matlock, Derbyshire, England.

http://www.colour-connections.com/

produced for defra sustainable clothing roadmap by phil...

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