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New Applications of Dyes in the Textile Industry

Arvind Patel

International Conference on Indian Dyestuffs IndustryHotel Hyatt Regency, Mumbai

September 21-22, 2006

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Overview – Global Scenario (Application of dyes)

Segmentwise application – Conventional dyes

Changing scenario of Textile Industry

Latest application techniques/New generation

dyes

Features of few latest application techniques

Key points – Dyehouse management

Structure of Presentation

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Textile Dye Classes – World Market Size

Disperse32.7%

Reactive29.4%

Acid12.4%

Direct4.6%

Others*14.9%

Vat6.0%

* Indigo, Azoic, Sulphur, etc.

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Global Textile Scenario – Consumption pattern

Blended42.0%

Cotton43.5%

Synthetic12.5%

Silk1.5%

Wool0.5%

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Indian Textile Industry

The Growth AspirationsThe Growth Aspirations

Indian Tex. Mkt2010: $ 85 bn

Indian Tex. Mkt2004: $ 38 bn

Domestic : $ 45 bn

Exports : $ 40 bn

Domestic : $ 25 bn

Exports : $ 13 bn

Source: Asian Text. J., Aug’06

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Segmentwise Application – Conventional dyes

Softflow

W inch

Knitted

Jigger / Jet

W oven

Package / Top Cabinet

Fibre / Yarn

Exhaust

Cold Pad-Batch(CPB)

Pad-Jig/Pad-Dry-Jig

W oven / Knitted

Sem i-Continuous

Pad-Dry-Pad-Steam(PDPS)

W oven

Continuous

Dyeing

Direct

Discharge

Resist

Flat bed /Roller / Rotary

Printing

Application

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Segmentwise application of Reactive dyes

Exhaust Hot

13.0%

Exhaust Warm40.0%

Pad - Batch15.0%

Continuous11.0%

Printing21.0%

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Conventional Printing methods

Rotary Screen58.0%

Flat Bed28.0%

Transfer5.0%

Intaglio3.0%

Hand Screen6.0%

Source: I.Holme, Supplement to Colourage, 2006, LIII(4), 103

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Textile Printing

Characteristics of textile printing dyes (Reactive) High solubility

Low substantivity

High diffusion

High print paste stability

Suitable for short fixation method Compatibility

Conventional Printing processes Direct Style

Discharge Style

Resist Style

Transfer Printing

Reactive Segment: MCT dyes – Direct printing & VS dyes – Discharge printing Pigment printing is much popular than reactive printing Research and Development

Liquid brand dyes for Direct printing & Ink Jet printing

Improvement of solubility of MCT based printing dyes

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Stringent Quality requirements led by export market

Higher pressure on Price – Trend towards high economy

Conservation of Energy / Utility Cost

Shift of manufacturing from Europe to Asia

Growing commoditization of Products

Modernisation, Automation & Re-structuring activities

Growing importance of Brands and Retailers

Fast changing consumer tastes

Newer fibres and blends

Better RFT and Reproducibility

Shade accuracy and quick delivery

Increase in the technical support requirements by the user industry

Textile Industry

Changing ScenarioChanging Scenario

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Drivers – Global Textile Supply Chain

 

            

 

 

 

 

 

• Less Dyestuff• Less Chemical• Less Water• Less Energy• Reduced Stock Costs

• Shorter cycles• RFT Performance• Robustness

Higher Productivity

Reduced Costs

• Shade Reproducibility• Colour Fastness• Eco-compliance

Product Integrity

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Repeated laundering fastness in presence of novel washing powders

containing Bleach activators like TAED / SNOBS

Fastness to Oxidative Bleach Damage (M&S C10A)

Light fastness (especially in pale depths)

Wet Light fastness (in association with residual detergent residues)

Perspiration / Light fastness

Chlorine fastness

Dry Cleaning fastness

Mercerisation fastness

Weathering fastness

Critical Fastness Requirements

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E-Control System

Digital Ink – Jet Printing

RFT Approach

Dyeing in Ultra Low Liquor ratio

Dyeing of Vat dyes in Soft-flow machine

Dyeing of Newer fibres & Blends (Lycra, Lyocell, modal, bamboo, soyabean,

etc)

Rapid dyeing Disperse dyes

CPB dyeing of Knitted fabrics

Application of Sulphur dyes – Environmental friendly dyeing

One –Bath Continuous dyeing of Polyester / Cellulose blends (without R.C.)

Pad – OX Process

Reactive dyeing – Perceptible shift from Hot dyeing to Warm dyeing process

Replacement of Vat dyes with Reactive dyes - achievement of Light and Wash

fastness properties.

Latest Applications / Concepts

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High Strength Reactive dyes – Economical for Medium / Dark shades

High Fixation –Polyfunctional Reactive dyes

Non – Photochromic Reactive dyes

Reactive dyes with improved Light fastness for pale depths (especially Red)

Reactive dyes – Stable under repeated laundering with bleach activator

containing detergents

Application of Reactive dyes at Neutral pH

Low Salt Reactive dyes

Fluorescent Reactive dyes for fashion & sportswear

Liquid Reactive dyes for Printing

Reactive Blue, which can withstand Chlorinated pool water fastness

New generation Dyes in the Textile Industry

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Liquid Vat dyes for Pad-Dry-Cure application

Modified Pre-reduced Liquid Vat dyes

High Wash fast Disperse dyes

Alkali stable Disperse dyes

Disperse dyes for dyeing of Microfibre

Dyes for Ink Jet Printing

Liquid disperse dyes for Printing

New generation Dyes in the Textile Industry

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Stability of Reactive dyes

• Under Alkaline conditionsFluorotriazine > Chlorotriazine > Difluorochloropyrimidine > Dichlorotriazine > Dichloroquinoxaline > Vinyl Sulphone

• Under Acidic conditions Vinyl Sulphone > Difluorochloropyrimidine > Chlorotriazine > Fluorotriazine > Dichloroquinoxaline > Dichlorotriazine

• To liquor containing perborateFluorotriazine > Chlorotriazine > Vinyl Sulphone > Dichlorotriazine > Dichloroquinoxaline > Difluorochloropyrimidine

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E-Control

Process One Step, Simple & Economical Continuous process

No unproductive batching sequence

Ideal for short lot dyeing

Effective Wash-off

A wide variety of fabric can be dyed Rapid shade matching in laboratory Energy efficient

Performance High Productivity due to short process

Environment friendly as no salt, urea & silicate are used

Soft handle of fabric due to mild fixation conditions

Migration is minimised by rapid fixation & humidity control

No crushing of pile fabrics.

Improved penetration of different fabrics - Presence of Humidity at high temp.

Very good Lab- to -Bulk & Bulk- to-Bulk reproducibility.

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Ink Jet Printing

Why Ink-jet? Simple technology and high quality

Existing colorants can be used [Reactive / Disperse / Acid / Pigment]

Constantly improving technology [Robustness, Speed (>100 m2/hr.), Quality (1440 dpi)]

Printing of innovative & unique designs

No screens / Unlimited colours in a design Outstanding colour gamut Different types of Substrates

Trend is towards digital photography (Home / Photolabs] Lower start-up costs & shorter production times Shorter time from design to print Supply chain advantages More design options

Reactive dyes in ink-jet printingPurified MCTs

Inks specially designed for existing ink jet head technology

Covalent bond gives excellent wash fastness

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Ink Jet Printing

Requirement is maximum fastness through non-covalent interactions Fastness requirements

Water fastness Humidity fastness Highlighter smear Light fastness

Achieving enhanced fastness Increase size of dye [Water fastness increases with size] pH switch [Differential solubility between ink and water] Hydrophobic effect Use of additives for greater longevity of prints

Current and future developmentsPhotographic media

Need for increasing light fastness

- New chromophores

- Improve performance of existing chromophores

Approaches [ Sacrificial groups / Physical quenchers / Physical protection]

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Raw material: Substrate Dyestuffs Chemicals Water

Preparation of Substrate

Process Conditions: Machine parameters

Liquor ratio

Time / Temperature profile

Dyebath pH

Concentrations of Chemicals

Dye / Chemical addition profile

Wash-Off profile

RFT Approach

Important FactorsImportant Factors

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RFT Approach

THE BENEFITS OFTHE BENEFITS OF

FINANCIAL• Lower Costs per

Batch

• Increased Output

• Improved Profit

margin

NON FINANCIAL• Better Customer

Service

• Improved Quality

• Reduced Effluent load

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RFT Approach

NON RFTNON RFT – Impact on Process Costs – Impact on Process Costs

RFT 1 Add 2 Adds BlackOverdye

Unlevel Off Shade& Unlevel

0

150

100

50

200

Rela

tive B

atc

h C

ost

100

118134

141

180

200

Dye Energy Water Chemicals Labour Fixed Drying

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RFT Approach

NON RFTNON RFT – Impact on Productivity – Impact on Productivity

100% RFT90% RFT80% RFT 70% RFT 60% RFT0

75

50

25

100

% M

ach

ine T

ime

% PRODUCTIVE TIME % REPROCESSING TIME

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Popular MythsPopular Myths

Severe Unlevelness

Oxidation Marks / Streak Marks

Patchy Dyeing

Layer to Layer variation

Centre to Selvedge variation

Lack of Solidity in shade

VAT dyes on Knits (Softflow Machine)

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Tips to achieve SUCCESSTips to achieve SUCCESS

Closed / Airtight Machines [Preferably HTHP Machines]

Overflow Rinsing facility over normal liquor level

Adjustment of rope length

Proper Cycle time (90-120 seconds)

Low Strike rate / Method 2 dyes are preferred

Dyes with Low Reduction Potential are preferred

Better results with higher MLR

Each Cubic Metre free air requires

1.7 Lts. (38oBe’) Caustic Soda & 1.7 kgs. Hydros

To check the presence of sufficient amount of Hydros frequently

Ensure Perfect dosing profiles

More amount of Lubricating agent

Vat dyes on Knits (Softflow Machine)

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High Strength dyes

Special Features & associated BenefitsSpecial Features & associated Benefits

Outstanding Tinctorial Strength Extra deep shades at lower conc.

High Degree of Fixation Lesser Water consumtion Lesser Colour in effluent

Excellent Fastness Properties Meets modern Customer’s Requirements

Robust system / Good compatibility

Achievement of RFT Results

Easy Wash-Off Outstanding Wet Fastness

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Strategies adopted by Colorant Manufacturers

• Growth in market share- Work towards profitable growth – Quality business with a good return

- Strategic alliances in specific activities

• Customer focus and innovation- Apply dye technology development to improve overall dyeing efficiencies

- Offer high quality technical service

- Innovative business with a continual flow of new products and application processes

- Develop synergic improvements with auxiliaries and process chemicals (package approach)

• Cost and Quality- Control production and distribution costs; manage the supply chain to reduce inventories

- Achieve rapid, on-time delivery

• Global presence- Improve and expand the marketing and technical service network in growing markets

• Environment- Have products and processes designed to lower the environmental impact

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Cost Reduction

RFT Approach

Technology Upgradation

Improved quality

Reduced cycle times

Reduced lead time for delivery

Perfect Repeatability

Reliable results satisfying critical fastness requirements

Maximum machine flexibility

International competitiveness

Much reduced environmental impact

Dyehouse Management

Key FactorsKey Factors

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Any Questions?

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Thank You Very Much