Yaa Command Of Tailing As Well As Listing Problems Inward Continuous Dyeing – A Systematic As Well As Practical Approach

Control of tailing in addition to listing problems inwards continuous dyeing – a systematic in addition to practical approach

Dr. Eng. Zeeshan Khatri
Associate Professor
Dept. of Textile Engineering,
Mehran University of Engineering & Technology, Islamic Republic of Pakistan

Introduction

The increasing requirement for dyeing larger batches, the demand for minimum shade variation throughout the length in addition to the shift from batch dyeing to continuous dyeing has led the textile coloration industries to see all aspects that impact tailing in addition to listing. Water consumption has to live reduced every bit good every bit the liquor-to-goods ratio.

Control of tailing in addition to listing problems inwards continuous dyeing Yaa Control of Tailing in addition to Listing Problems inwards Continuous Dyeing – a Systematic in addition to Practical Approach

Fig: Problems inwards dyeing

Shade consistency is an additional payoff of continuous dyeing in addition to longer runs are possible alongside minimum shade variation. There is the demand for, in addition to increasing possibility of, automation in addition to command of all the dissimilar aspects of the dyeing processes.

Market trends forcefulness dyers to live fully abreast of the latest requirements demanded yesteryear a buyers’ retail marketplace alongside much shorter fashion seasons. Two of the major problems encountered yesteryear dyers are tailing in addition to listing. The dyer must see all factors influencing listing in addition to tailing right from greige to finished fabric.

This is a comprehensive article identifying the factors influencing color variation, factors which tin displace listing in addition to tailing. H5N1 systematic in addition to practical approach is adopted inwards a mode which tin live used every bit a practical guide for dyers in addition to colourists.

Research in addition to Development
It is necessary to review the yesteryear inquiry into color variations such every bit listing in addition to tailing in addition to developments.

Dye makers in addition to mechanism manufacturers direct hold been involved inwards inquiry in addition to evolution for many years, advancements inwards weaving direct hold occurred to make to a greater extent than consistent textile properties.

Dye, fibre in addition to chemic manufacturers direct hold made contributions inwards fibre in addition to dye chemical scientific discipline including improvements inwards dye substantivity in addition to affinity, ionic characteristics, fastness properties, mechanical in addition to thermal demeanour in addition to alongside the introduction of to a greater extent than fibre reactive dyes alongside stronger dye–fibre interactions.

Machine manufacturers direct hold produced to a greater extent than command systems that are robust inwards a plant province of affairs every bit well. Indirect heating inwards chambers, radiations drying, engineered padders in addition to troughs, dye dispensing in addition to online color measuring are a few examples of recent advancements.

The percentage of the dyeing squad has a tremendous influence inwards producing character textile in addition to is solely possible when qualified in addition to skilled squad members are there.

Tailing in addition to listing
Tailing is shade variation along the length of the textile in addition to is determined yesteryear a serial of comparisons of the color from the start metre to the last, checked in addition to measured during the dyeing process. For example, if 10000 m of textile is to live dyed inwards a continuous dyeing range, the dyeing is started in addition to the shade beingness matched is sampled in addition to agreed in addition to this sampling is continued upwards to the cease of the 10 000 m at intervals.These intervals depend on yesteryear history of the dyes in addition to textile beingness dyed. The term ‘ending’ has every bit good been used every bit good every bit listing.

Listing is shade variation across the width of the textile in addition to it is every bit good checked during dyeing. Variation tin live from side-to-side or side-to-centre. When the textile runs inwards opened upwards width this parameter should non live ignored in addition to must live checked inwards a similar mode every bit the tailing. When dyeing inwards jet machines where the textile is inwards a rope form, listing is rarely a dyeing machine problem.

Testing staff should live made aware of the phenomena of thermochromic effects every bit for certain chromophores tin exhibit vast temporary color changes. The number of wet on shade should live considered particularly when urgent orders are beingness processed. Shade varations tin give off inwards finishing but these effects should direct hold been checked inwards the laboratory.

Continuous dyeing processes
Most fabrics are treated in addition to run continuously on machines for treatments such every bit bleaching, pad application such every bit thermosol dyeing in addition to pad–steam in addition to the many washing off procedures used at all processing stages.

Greige textile is received yesteryear the greige region where total details of the fabric,the job/lot numbers in addition to the total processing road are issued. The textile may demand to live tested to determine size content, grams per foursquare meter (GSM), width and, if necessary, suspect unusual impurities are checked. See Appendix 1 for the hit of tests needed.

All fabrics to live processed direct hold to live checked against the textile standard, particularly alongside repeat orders. Fabric is passed for the singeing in addition to desizing process where it is unremarkably singed at high speed in addition to padded alongside the liquor containing desizing agent The desized textile is so washed and/or dried earlier passing to the continuous bleaching hit for scouring and/or bleaching. Correct scouring in addition to bleaching alongside fully controlled washing is necessary. An optional mercerising physical care for may live carried out either earlier or after bleaching depending on the cease use.

General factors influencing listing in addition to tailing
An supposition has to live made that for large dyeing orders the textile is fully suitable for utilisation in addition to has consistent properties. Factors influencing tailing in addition to listing include variation inwards yarn count, yarn twist, textile density in addition to width GSM of the greige fabric. Sizing agents should live H2O soluble. Uneven size application affects the grade of desizing.

Tailing in addition to listing problems tin live caused yesteryear 2 controlling factors, namely:

Equipment parameter changes or variations or
Eye properties.

Equipment command parameters
Correct singeing/desizing: this has a major influence on listing, if singeing or desizing varies across the width. Where pad batch processing is used, batching equipment alignment is really important.

Uneven padder pressure level at whatever phase inwards desizing, washing, scouring, bleaching, dye application in addition to washing off tin displace variations in addition to thus listing tin occur. Faulty padder equipment is the close probable displace of listing. The private padder pressures from left, centre in addition to right play a dominant percentage in addition to direct hold a at nowadays number on listing in addition to tailing. Padder diameter variation across the width may every bit good producing listing. Variation of air of hydraulic pressures tin Pb to variable padding expression. H5N1 long run of smaller width textile volition larn out an impression across the width on the padder, which volition larn out an impression on wider textile that volition exhibit upwards during dyeing.

Some companies invest inwards keeping 2 dyeing padders operative inwards 1 dyeing hit where wider in addition to little width changeover is frequent, 1 for narrow textile width in addition to the mo for wider width fabric, inwards society to avoid whatever variation caused yesteryear the padder in addition to every bit good to growth the life of the padder.

Mercerising: variations inwards the grade of mercerizing across the width displace listing in addition to should live controlled. The washing physical care for needs careful control.

The drying or dye fixation of textile must live controlled in addition to even, inwards society to ensure a consistent wet content. H5N1 stenter must live fully controlled inwards price of temperature in addition to recycling. Even temperature is needed when at that topographic point are dissimilar temperature zones. Over- or under-drying tin displace listing afterward inwards the dyeing physical care for where at that topographic point is steam injection for thermosol processes; command is paramount.

H5N1 major command employment that is caused yesteryear dye properties tin live corrected yesteryear adept padder design.

Control of washing off: this is vital for both character in addition to effluent in addition to environmental considerations. Water catamenia inwards each tank must live controlled throughout the production run; the padder pressures in addition to the status of the padders inwards each washing sleeping room should regularly live checked. Variation inwards washing temperature, feeding charge per unit of measurement of lather in addition to neutralizing acid tin every bit good occupation organisation human relationship for listing in addition to tailing.

The book of dye liquor for long runs has to live established in addition to mixing tanks provided for shade continuity. The padding expressions for the textile to live padded direct hold to live decided. The padding trough book has to live sufficient to halt tailing due to variable ‘strike’ inwards a can containing a mixture of dyes of differing dye properties.

Dyeing properties in addition to the number on tailing in addition to listing
Different dyes tin direct hold vastly dissimilar dyeing properties in addition to it is of paramount concern that the dye manufacturers’ recommendations live followed. Dyes that direct hold been matched alongside other dyes are to a greater extent than probable to give similar dyeing characteristics. Colours direct hold dissimilar substantivity in addition to affinities, oftentimes at dissimilar temperatures in addition to inwards the presence of added electrolytes commonly used inwards dyeing procedures. For example, a mixture of iii dyes inwards a padding can mightiness direct hold differing substantivities. If the pad can is large or the liquor feed command wretched in addition to the machine is running to a greater extent than like shooting fish in a barrel because of a heavy fabric, 1 of the dyes mightiness live removed from the can to a greater extent than speedily – thence the start of a tailing situation. This employment was given a elevate inwards the really early on days of dyeing, the employment of ‘strike’.

It is essential that adept records of dyeing problems live kept so that for certain mixtures of dyes for for certain fabrics tin live avoided if possible or special attention taken.

The dye manufacturers direct hold spent fourth dimension in addition to coin on developing efficient dyeing systems in addition to their efforts should live used to create a feasible in addition to prosperous industry.

Shade evaluation in addition to quantifying listing in addition to tailing
Visual assessment is carried out inwards a touchstone lite bo x. For listing, width-wise textile is stitched to adjust iii areas marked every bit left, centre in addition to right; this article is so assessed inwards a touchstone lite box alongside specified lite such every bit D65, TL84, Inca or CWF. For tailing, a number of textile samples are collected at 500 m intervals in addition to assessed against the customer’s touchstone inwards a lite box. The number of samples in addition to intervals vary according to the total length beingness dyed inwards bulk.

Spectrophotometric in addition to figurer color matching systems tin live used instead of the visual assessment procedure, but this needs to live done against defined standards. The client touchstone is taken every bit a reference for measuring inwards a spectrophotometer in addition to so compared to the production run.

Where at that topographic point are problems, a checklist tin live used in addition to a listing for both listing in addition to tailing is given inwards Appendix 2.

All of these factors direct hold dissimilar impacts depending on the fabric, the fibre in addition to the dyeing system. Herein lies the science of the colourist.

Conclusions
Dyeing alongside consistent shade is the primal to success, regardless of whether shorter or longer runs are beingness employed. The global marketplace is constantly changing in addition to this rapid alter of shades is at nowadays mutual every bit the retail lifespan of fashion is drastically reducing. Dyeing shorter runs inwards continuous processes keeps dyers on a tightrope in addition to achieving consistent shades alongside the minimum amount of rejections has decease a gigantic task.

Since large investments inwards continuous dyeing could live decreasing due to the emerging tendency of doing shorter runs, the pressure level at nowadays is on dyers to accomplish consistent shades alongside minimum variations. Under these circumstances, the dyer should live technically audio using all the information available to him so that the pressures to make character shades alongside the available resources is achieved consistently. This volition live for his own, in addition to the company’s, survival inwards the market.

Appendix 1: Predyeing tests for command of tailing in addition to listing

Suggested examine	Method	Reason for test	Result
Fabric GSM width/ length	GSM cutter alongside weighing scale.	To ensure no textile variations inwards weights	Uniform final result avoids listing in addition to tailing problems inwards subsequent dyeing process
Fabric pilling	ICI pilling tester or NuMartindale	In society to banking concern check the textile pills	Shows singeing efficiency
Degree of desize	Iodine driblet examine for grade of desize.	To assess the extent of starch removal from textile during desizing.	Variation volition live to a greater extent than apparent inwards instance of dyeing reactive in addition to vat dyes
Absorbency	Capillary method alongside either fourth dimension constant or bird constant. Drop examine method alongside sink-in fourth dimension in addition to spreading diameter	To banking concern check the textile absorbency left, centre in addition to right; in addition to alongside grand m intervals along the length.	Gives an thought of textile pick-up variation in addition to tin so live controlled accordingly during dyeing. H5N1 lot tin live segregated prior to dyeing if whatever major variation is observed.
Fabric pH	Drop examine in addition to pH yesteryear extraction method	To banking concern check pH of textile left, centre in addition to right – must live neutral	Measures the textile pH which tin displace listing in addition to tailing problems if this varies inside the lot
Degree of mercerising	Barium number	To banking concern check the grade of mercerising; sampling at 2000–3000 m intervals.	Shows the absorbency variation across the width in addition to along the length
Degree of whiteness	Spectrophotometer	To banking concern check the textile grade of whiteness	Consistent whiteness along the length ensures shade consistency in addition to puts the focus of variation on other causes