HI-TECH WET PROCESSING (recent trends and issues) © James Park C. Col., FSDC., C. Text, FTI.

HI-TECH WET PROCESSING(recent trends and issues)

© James ParkC. Col., FSDC., C. Text, FTI.

BACKGROUND

TEXTILES AND GARMENT PRODUCTION – MATURE INDUSTRIES

MAJOR SECTORS OF THE GLOBAL ECONOMY

FIBRE CONSUMPTION - 81 MEGATONNES INCREASING USE OF POLYESTER

EMPLOYEES – 26 MILLION WORLDWIDE

MAJOR TECHNOLOGIES - LONG ESTABLISHED

BUTCONTINUOUS DEVELOPMENT

PARTICUALRLY IN WET PROCESSING

DRAMATIC CHANGE FROM:

PRODUCTION-LED (VERTICAL) MANUFACTURING

TO

RETAIL-SPECIFIED MANUACTURING

(CONCEPT TO CONSUMER – C2C; GLOBALISATION AND GEOGRAPICAL CHANGES; LONG SUPPLY CHAINS)

CHANGE HAS REQUIRED NEW CONCEPTS:

JUST-IN-TIME (JIT) PRODUCTION

WITH

RIGHT-FIRST-TIME (RFT) PROCESSING

AND

QUICK RESPONSE (QR)TO MEET CONSUMER DEMANDS

(ESSENTIAL WITH LONG SUPPLY CHAINS)

Concept Benefits

Quick response (QR)

Reduction in stockholdingMeeting immediate demands of customer

Just-in-time (JIT)

Reduction in stockholding

Right-first-time (RFT)

Necessary to give QR and JITMajor financial savingsImproved quality and productivity

BENEFITS OF MODERN CONCEPTS

Cost Productivity Profit

Blind dyeing 100 100 100Small addition 110 80 48Large addition 135 64 -45Strip and re-dye 206 48 -375

COST COMPARISONS

In addition :- LOSS OF REVENUE AND PROFIT BY REPROCESSING RATHER THEN NEW BATCHES- EFFECT ON DESIGNED CAPACITY

•reduction in processing time•reduction in energy use•reduction in water and effluent•shortened lead times•reduced waste•better machine utilisation through production planning•reduced capital expenditure on processing equipment•reduction in dye and chemical inventory and costs

OTHER SAVINGS FROM RFT PROCESSING

Factor Monitor by lab

Control by SOP

Exht CD

Startingmaterials

Purity of water X

Substrate dyeability X

Substrate preparation X X

Dye standardisation X

Moisture content of dye X

Dyeingprocesscontrol

Weight of substrate X

Weighing and dispensing of dyes X X

Weighing and dispensing of chemicals X X

Control of liquor ratio X

Control of pH X X

Time/temperature profile X

Control of liquor flow/machine speed X X

Control of liquor circulation X

Colourcontrol

Selection of dyes X X

Behaviour of dyes in combination X X

Accuracy of laboratory dyeing X XAccuracy of transfer to bulk X X

Batch to batch reproducibilty in bulk X

Method of colour assessment X X

Determination of metamerism index X

IMPORTANT FACTORS FOR RFT PROCESSING

Saving in total dyeing cost of 30% (ranges from 24 to 36% depending on substrate type and dyeing method) for each correction eliminated through RFT dyeingReduction in dye inventory to 25% of originalReduction in dye purchases by 30% (ranges from 25 to 45%) by selecting least-cost formulations

Elimination of dyeing full to standards (10% of dye cost)Reduction in reprocessing (typically from 4 to 1.5%) Reduction in laboratory dyeing to achieve target colour (typically 8 to 2)Fabric savings due to colour sorting (10% of annual fabric purchases)

TYPICAL COST SAVINGS

NOT ALL WET PROCESSORS WORLDWIDE HAVE YET

ACHIEVED THE FULL BENEFITS OF RFT PRODUCTION

THE SUPPORT LABORATORY MUST BECOME THE NERVE CENTRE OF

THE OPERATION

Dye evaluation, selection, testing, QC

Development of application methods

Database preparation/colour matching

Substrate evaluation

Preparation of SOP

USE OF ENGINEERED COLOUR TEXTILE STANDARDS

COLOUR MEASUREMENT TECHNOLOGY:

WIDELY USED AND GIVES MAJOR BENEFITS

GREATER USE REQUIRED OF:

COLOUR SORTING ENGINEERED COLOUR STANDARDS

CONTROL TECHNOLOGY:

WIDELY USED FOR:

DISPENSING SYSTEMS

MACHINE/PROCESS CONTROL

GREATER USE REQUIRED FOR:

TOTAL MANAGEMENT TECHNIQUES

LATE STAGE PROCESSING:

- PACKAGE DYEING OF YARN- FABRIC AND GARMENT DYEING- PRINTING

OTHER AIDS TO QUICK RESPONSE

ALTERNATIVE PROCESSING ROUTES

CUT AND SEW COTTON GARMENTS

FULLY-FASHIONED COTTON GARMENTS

TEXTILE PRINTING

ACCOUNTS FOR 15% OF TEXTILE PRODUCTION

(28 BILLION SQ METRES PER YEAR – WITH 2.5% ANNUAL GROWTH)

TRADITIONAL METHODS – UP TO 20 WEEK SEQUENCE

COMPARISON OF ROUTES

Durst Konica Minolta StorkHangzhou Honghua MS Italy Xennia TechnologyLa Meccanica Reggiani Zimmer

HIGH PRODUCTION DIGITAL TEXTILE PRINTING MACHINES (2011)

Benchmarking varies between manufacturersUsually 8 colour machinesQuoted speeds of 400 to 3000 m2/hour

ZIMMER COLARIS

DIGITAL PRINTING (2011):

NOW MATCHING PRODUCTION SPEEDS OF FLAT SCREEN METHODS

APPROACHING SPEEDS OF ROTARY SCREEN METHODS

CURRENTLY ABOUT 1% OF TOTAL PRINTING PRODUCTION

FORECAST TO BE 2% OF PRINTING PRODUCTION BY 2015?

DIGITAL-PRINTING (2012) :

DIGITAL-PRINTING WITH PIGMENTS POSSIBLE(PIGMENT PRINTING MORE THAN 50% OF MARKET)

PRODUCTION OF 7,200 sq m/hour

COMPLEX CRITERIA FOR DIGITAL PRINTING INK SELECTION

DEPENDS ON : FABRIC TYPE COLORANT TYPE COMPONENT COMPATIBILITY PRINTING HEAD

TYPICAL TESTING REGIME – 18 PARAMETERS

EVALUATES: COMPATIBILITY WITH PRINTING ELEMENT SHELF LIFE INK FEED PERFORMANCE IMAGE QUALITY AND FASTNESS PROPERTIES

OTHER ISSUES AND PRESSURES ON TEXTILE CHAIN

INCREASING PRESSURE DUE TO:

OCCUPATIONAL HEALTH ENVIRONMENTAL SAFETY SAFE WORKING CONDITIONS FAIR LABOUR PRACTICES /SOCIAL JUSTICE

SUSTAINABLE TECHNOLOGY:

PROCESSES WHICH DO NOT INCUR:

EMISSION OF GREENHOUSE GASESTHE USE OF NON-RENEWABLE MATERIALSGENERATION OF WASTE

AAFA Adidas C&A Coats Liz Claiborne

Decathion Esprit Gap H&M Hanesbrands

IKEA Levis M&S Next Nike

Nordstrom S. Oliver Otto J.C. Penney Puma

REI Ann Taylor Tesco Timberland VF Corp

RESTRICTED SUBSTANCES LISTS(just a few examples)

PARTICULAR PROBLEMS WITH:

TRADITIONALLY CULTIVATED COTTON(Preparation)

POLYESTER(HT Dyeing)

(More than 80% of fibre usage)

NOT YET ENOUGH ‘ORGANIC’ COTTON

SUPERCRITICAL CO2 – WATERLESS DYEING MACHINE

ScCOO DYEING

PILOT (PACKAGE) MACHINE (1991)

FABRIC DYEING MACHINE

DYECOO SYSTEMS + NIKE

Needs : DYES + EQUIPMENT

Process :

WATERLESSSAVINGS IN ENERGY,

CHEMICALS AND TIME

NOT TOXIC

•reduction in water consumption•reduction in pollutants and volume of discharged effluent•savings in energy, including heat recovery•reduction in atmospheric pollution •minimising waste•health and safety of operatives•elimination of prohibited chemicals in consumer products

TOWARDS THE ‘GREEN’ DYEHOUSE

Development of efficient standard operating procedures (SOP) Following SOP exactly, assisted by automation Installation of machines operating at low liquor ratios Operating at minimum liquor ratio by processing full machine loads Monitoring liquor levels, assisted by automation, to avoid overfilling Improved production scheduling to avoid unnecessary machine cleaning and downtime

Replace direct heating by heat exchangers to avoid liquor volume increases Control rate of flow of cooling water through heat exchangers Return cooling water from closed-coil systems Use of water-soluble lubricants to eliminate separate scouring Combine processes or use one-bath methods whenever possible Avoid after treatment or excessive rinsing, especially overflow rinsing Allow drainage time between rinses Adopt counter-current rinsing methods in continuous processing Reuse relatively clean rinsing water for processes not requiring high-quality water Partial purification and bath reuse Total water purification and recycling Digital printing techniques

MEASURES TO REDUCE WATER CONSUMPTION

Area for consideration Factors for improvement

Water Use of low liquor ratios – machines fully loadedCombining processesWater re-useContinuous preparation, including cold pad batch methods

Effluent Treatment and water recyclingEnergy Insulation of pipes and vessels

Heat recovery from HT processes (heat exchangers)Low temperature processingUse of inverter-driven electric motors

Pollution Atmospheric control on stentersHealth and safety Colour dispensary management – individual protective

clothingSafety equipment on HT machineryElimination of hazardous or dusty chemicalsElimination of chemicals and colour in waste waterElimination of prohibited chemicals on consumer products

Dye and chemical costs Colour measurement technologyFollowing SOPs

IMPROVEMENT MEASURES

INSULATION – INSULADD COATING

Parameter Equipment improvements

Process equipment

CPB preparationLow LR/horizontal spindle package dyeing machinesRadio frequency (RF) dryingLow LR/pneumatic circulation jet dyeing machinesModern stenter installationImproved plant layoutDigital printing techniques

Control equipment

Process control, automation and robotics, managementAutomated/robotised dye and chemical weighing and dispensingColour measurement technology including digital colour communication/distance QC

Chemicals Size recoveryCaustic recovery and re-use

Water and effluent

Recovery, recycling and re-use based on in-house effluent treatment

EQUIPMENT UP-DATES

EFFLUENT TREATMENT AND WATER RECYCLING

TREATMENT ALTERNATIVES

CASE HISTORY – COTTON AND SYNTHETIC FABRICS

RAW AND TREATED EFFLUENTS

MANY DYEHOUSES TREATING EFFLUENT – RELATIVELY FEW RECYCLING TO OBTAIN MAJOR PAYBACK

SIMPLE FLOCCULATION WILL MEET CONSENT LIMITS – HIGH CHEMICAL COST

CROSSFLOW MEMBRANES PROVIDE BEST QUALITY -95% RECYCLING POSSIBLE

MEMBRANE FILTRATION WILL REDUCE COD, SUSPENDED SOLIDS AND COLOUR

RIVER WATER QUALITY IS IMPROVING WORLDWIDE WITH THE ABOVE.

CURRENT SUMMARY OF EFFLUENT TREATMENT AND RECYCLING

IN SUMMARY:

WET PROCESSING IS A HIGH-TECHNOLOGY ACTIVITY

SUCCESSFUL OPERATIONS DEPEND HEAVILY ON A MODERN SUPPORT LABORATORY

COLOUR MEASUREMENT AND CONTROL TECHNOLOGIES ARE WIDELY USED GIVING MAJOR BENEFITS AND COULD BE EXPANDED

EQUIPMENT AND PROCESSES ARE AVAILABLE TO MEET THE INCREASING DEMANDS AND PRESSURES OF THE TEXTILE CHAIN

THANK YOU FOR YOUR TIME AND KIND ATTENTION