bluuebunny/crossref_metadata_2025 huggingface dataset:
Photostability of Anthraquinone and Azo Dyes in N‐Ethylacetamide (Nylon Model)
Authors: Chang I Y , Miller I K
Published: July 2010

Measurements of the quantum yields of photodegradation of anthraquinone and azo dyes in N‐ethylacetamide (nylon model) and triplet sensitisation of dye fading showed that the photochemical reactions are initiated by an upper excited n‐π* triplet state. The primary photochemical reaction with both anthraquinone and azo dyes involves hydrogen abstraction from the amide so/vent. In some cases oxygen retards dye fading by reoxidation of the reduced structures. In other cases oxygen accelerates the photochemical reaction via free‐radical initiated oxidation reactions. The quantum yields of dye fading are strongly wavelength dependent. On exposure to a simulated sunlight spectrum photodegradation is mostly caused by radiation in the region 300–400 nm. While unsubstituted anthraquinone is very photoreactive, amino‐substituted anthraquinones are much more photostable in N‐ethylacetam/de. Photostability of mono‐ and di‐substituted anthraquinone derivatives increases with the electron‐donating power of substituent groups. Azo dyes with increased conjugation such as diazo and naphthazo structures are more photostable than simple azobenzene derivatives. Certain electron‐withdrawing substituents, which do not affect dye colour, improve the ‘oxidative’ photostability of both anthraquinone and azo dyes. A cobalt premetallised azo dye (C.I. Acid Red 182) is very photostable in N‐ethylacetamide, showing the effect of metal chelates on photostability. The low values of quantum yields for the dye solutions are comparable with those of acid and disperse dyes in nylon films, indicating that N‐ethylacetamide is a suitable nylon model for mechanistic studies of dye fading.
Advances in the Afterchrome Dyeing of Wool
Authors: Welham Arthur C
Published: July 2010

Recommendations are outlined for the afterchrome dyeing of wool to give minimum chrome residues in dyehouse effluent and minimum wool damage. Particular reference is made to the use of a new product Lyocol CR, which reduces chrome residues in exhausted dye liquors and ensures efficient utilisation of minimum chrome additions, thus giving good wet fastness. Low‐chrome methods permit the wider use of chrome dyes for machine‐washable wool and new dyes which increase the shade gamut available are discussed.
A critical appraisal of the u.v. spectrophotometric determination of the mothproofing agents Eulan WA New and Mitin FF High Cone on wool
Authors: Wimbush Jeremy M
Published: July 2010

A previously published method for the u.v. spectrophotometric determination of Eulan WA New (or Eulan U33) and Mitin FF High Cone used as mothproofing agents on wool is critically assessed. Evidence is presented which shows that this procedure is not sufficiently accurate for the determination of Eulan WA New (or Eulan U33) on wool. However, the u.v. spectrophotometric determination of Mitin FF High Cone shows no evidence of bias and may be suitable for the determination of this agent on wool. The preparation of blended wool tops for use as analytical standards is described.
BFD(l:c)colour‐difference formula Part 1ndashDevelopment of the formula
Authors: Luo M R , Rigg B.
Published: July 2010

The available experimental data relating to small colour differences between pairs of surface colours have been combined together into sets including perceptibility results and acceptability results. Supplementary experiments have been carried out to enable all the previous visual results to be brought on to a common scale, and to provide extra information when this was considered necessary.

A new colour‐difference formula, BFD(l:c), has been developed using the combined experimental results. Various aspects of colour differences have been considered in turn to decide the form of formula required, and the constants in the formula have been optimised using the combined perceptibility and acceptability results. The new formula is similar in structure to the CMC(l:c) formula in most respects. However, it was found that a new term was required to take account of the fact that when chromaticity discrimination ellipses calculated from experimental results are plotted in a b space, they do not all point towards the neutral point. The experimental results were not very consistent with respect to possible tilting of discrimination ellipsoids relative to the xy plane. Overall it seems that any such tilting is quite small and in the direction implicit in the CMC and BFD formulae. Experimental results based on both acceptability and perceptibility judgements form part of the same overall pattern except for the weighting of lightness differences relative to hue and chroma differences.
Dyeing properties of sulphamic acid‐treated wool
Authors: Cameron B A , Pailthorpe M T
Published: July 2010

The dyeing behaviour of wool pretreated with sulphamic acid has been investigated. Sulphamic acid introduces sulphonate groups into wool's structure and, when dyed with basic dyes, sulphamic acid‐treated wool has an increased uptake of basic dyes. The light fastness of such dyeings was found to be better than that on untreated wool, being comparable to values obtained on acrylic substrates. The increase in light fastness was investigated using model PVA films. The wash fastness of basic dyes on sulphamic acid‐treated wool was found to be disappointingly low, although the fastness to dry cleaning would be commercially acceptable. Dyeing with an acid dye demonstrated the good resist properties to anionic dyes of the sulphamic acid‐treated wool.
The flow properties of foam
Authors: Kroezen A B J , Wassink J Groot , Schipper C A C
Published: July 2010

The rheological behaviour of foam, prepared from an aqueous solution with lauryl sulphate as surfactant, has been measured with a viscometer as a function of the blow ratio, bubble diameter distribution and concentration of the thickener used. The influence of wall slip and of hysteresis effects on the rheological behaviour have been determined. Calculations and measurements pertaining to the pressure drop in pipes have been performed, in which the foam was considered as a compressible pseudoplastic whose rheology depended on blow ratio. The distribution of the foam passing through a closed distribution unit has been studied. This distribution unit consisted of a pipe and a cross‐head distribution slit. Complementary measurements of the flow of foam through narrow slits have been made. The design of a closed foam distribution unit is discussed. The consequences of the choice of several design parameters are examined.
Dye‐fibre bond stabilities of dyeings of bifunctional reactive dyes containing a monochlorotriazine and a ß‐hydroxyethylsulphone sulphuric acid ester group
Authors: Matsui Masaki , Meyer Ulrich , Zollinger Heinrich
Published: July 2010

The dye‐fibre bond stabilities of various bifunctional dyes (commercially known as Sumifix Supra dyes) have been investigated by measuring the kinetics of dye‐cotton bond hydrolysis in aqueous buffer solution at 98d̀C. The stabilities are generally found to be somewhat higher than those of comparable monofunctional reactive dyes. Significantly better, however, is the fixation yield of the bifunctional dyes. Reasons for a very low uptake of a non‐commercial bromamine acid‐based bifunctional dye are discussed.
Synthesis of some cobalt phthalocyanine‐3 3 3 3‐tetrasulphonamides and spectroscopic studies of their application to cellulosic fibres
Authors: Yahya Hazim K , Kazandji Salwa Y
Published: July 2010

The treatment of cobalt phthalocyanine‐3, 3′, 3″, 3′″‐tetrasulphonylchloride with different primary amines with different substituents has given eight novel cobalt phthalocyanine‐3, 3′, 3″, 3′″‐tetrasulphonamide compounds. The structure determination have been carried out using elemental analysis, molecular weight measurements and infra‐red spectroscopy. Direct application of the new synthesised dyes to cotton and viscose fabrics at two different bath concentrations gave a range of percentage reflectances values in the visible region. The absorption maxima appeared in both cases in the range 670–680 nm.
Substituent effects on the colour, dyeing and fastness properties of 4‐arylamino‐5‐nitro‐(and amino)‐1, 8‐dihydroxyanthraquinone and 4‐arylamino‐8‐nitro‐(and amino)‐1, 5‐dihydroxyanthraquinone disperse dyes
Authors: Peters A T , Chao Y C
Published: July 2010

Condensation of arylamines with 4, 5‐dinitro‐l, 8‐dihydroxyanthraquinone and 4, 8‐dinitro‐1, 5‐dihydroxy‐anthraquinone afforded the corresponding 4‐arylamino derivatives, reduction of which gave 4‐arylamino‐5‐amino‐1, 8‐dihydroxyanthraquinones. The influence of various electron donor and acceptor substituents in the arylamino residue is assessed and dyeing and fastness properties of the dyes on polyester evaluated. Comparison is also made between the bromo‐substituted derivatives obtained by bromination of the 4‐anilino derivatives with those unambiguously synthesised from condensations with bromoanilines
The efficiency of reaction between reactive fluorescent whitening agents and wool
Authors: Davidson R Stephen , Ismail Gulam M , Lewis David M
Published: July 2010

Potential fluorescent whitening agents (FWAs) containing halogen atoms which intramolecularly quench fluorescence have been synthesised and applied to wool in a number of ways. Application by cold pad‐batch methods revealed that the complete displacement of all halogen atoms by nucleophilic groups in wool did not take place. Treatment of these materials with morpholine, sodium carbonate or water was necessary to develop the full potential fluorescence yield of the FWA on the fabric. The fluorescence of FWAs can be quenched by the heavy atom effect, as shown by the fact that no fluorescence was observed when commercial FWAs were applied to brominated wool. If the FWA‐treated brominated fabrics were subjected to a reduction treatment then the bromine atoms were removed and the fluorescence of the FWA was restored. Application of the potential FWAs by exhaustion, with thioureadioxide present in the liquor, at high temperatures always led to strongly fluorescent fabrics, implying that the halogen atoms were completely displaced using this application method, but the question remains as to how much of the displacement leads to covalent bonds between the fabric and the FWA.
Ethoxylated amphoteric products in wool dyeing
Authors: Cegarra J. , Riva A.
Published: July 2010

The influence of some amphoteric compounds and their degree of ethoxylation on both the aggregation state of two acid dyes and the dyeing kinetics of these on the wool fibreshas been studied. The formation of amphoteric product‐dye complexes and their redissolution in the micelles of the amophoteric compound has been observed; the amphoteric product‐dye molar ratio and the degree of ethoxylation of the amphoteric product have important influences. Rates of dyeing in the presence of an amphoteric product are, in general, faster than when the dye is present alone; the increase in ethoxylation reduces the absorption rate of the dye. A relationship between the aggregation state of the dye and its rate of dyeing has been established.
The Donnan approach to equilibrium sorption of cationic dyes by acrylic fibres: a literature survey
Authors: Alberghina G , Amato M E , Fisichella S
Published: July 2010

A theoretical equation for determining the sorption of cationic dyes by acrylic fibres, based on a simple Donnan approach and on the assumption that there were two different types of anionic sites with different dissociation constants, has been used to review some data of the literature. The results obtained confirmed that the simple Donnan approach could explain the dyeing mechanism of acrylic fibres with cationic dyes.
Acquisition and use of data for assessment of the environmental impact of colorants
Authors: Hobbs Susan J
Published: July 2010

The Notification of New Substances Regulations 1982 require information about new chemicals to be submitted to the national competent authority prior to placing them on the European Community market. The information must be of sufficient quantity and quality to allow an assessment to be made of the new chemical's impact on the environment. The data given in the notification need to be supplemented with information about the use, release and behaviour of the new chemical. For dyes this was collected during a survey of the industry, to produce estimates of environmental concentrations. These are compared with the concentrations at which adverse effects have been recorded in ecotoxicity tests, to make an initial assessment of the effect of manufacturing and using the new chemical.
Ion absorption by acrylic fibres. 1 – The absorption of single ions
Authors: Alberti Guido , Loi Aldo
Published: July 2010

The equilibrium and kinetics of absorption of alkaline ions by acrylic fibres deprived of their ion content were studied and comparison was made with an organic cation and a basic dye.
Modification of cotton to improve its dyeability. Part 2 – pretreating cotton with a thiourea derivative of polyamide–epichlorohydrin resins
Authors: Burkinshaw S M , Lei X P , Lewis D M , Easton J R , Parton B , Phillips D A S
Published: July 2010

A new method of pretreating cotton to improve its dyeability, using an aqueous solution containing polyamide–epichlorohydrin (PAE) resin and thiourea is introduced. The effect of dyebath pH on the colour yield, fixation and build–up of Procion HE, H and MX (ICI) dyes on the pretreated cotton, together with the quality of the dyeings obtained when using the new method and mechanistic implications, are discussed.
Modification of cotton to improve its dyeability. Part 3 – polyamide–epichlorohydrin resins and their ethylenediamine reaction products
Authors: Lei X P , Lewis D M
Published: July 2010

The effect of pretreating cotton with a polyamide–epichlorohydrin resin and ethylenediamine is described. The treated substrate has enhanced substantivity for reactive dyes, which may be applied without electrolyte simply by setting the dyebath to pH 5 and raising the temperature to the boil. Dyed samples exhibit good brightness and very high wash fastness, but in many cases the light fastness is impaired.
I K Varma*
Authors: Rao B V , Choudhary Veena
Published: July 2010

The paper describes the synthesis and characterisation of various alkylaminoanthraquinone dyes based on caprolactam and 11–aminoundecanoic acid. These dyes were characterised in terms of their elemental composition and i. r., n. m. r. and mass spectrometry. The dyes synthesised in the present work were stable up to 320°C and started to decompose above this temperature. Increasing the alkyl chain length of carboxyalkylamino substituents resulted in an increase in dye uptake during dyeing.
Effect of acylation on the dyeing and fastness properties of some azo dyes
Authors: Rao B V , Vaidya A A , Choudhary V , Varma I K
Published: July 2010

The changes brought about by acetylation, benzoylation and terephthaloylation of some disperse dyes derived from 4–aminoazobenzene on the dyeing and fastness properties are described. Dyes substituted by benzoyl and terephthaloyl groups tended to have better light, wash and sublimation fastness on polyester. The dyes showed good build–up when these groups are coupled with an N–β–cyanoethyl group. Acylation of azo dyes resulted in poor substantivity and poor fastness properties on nylon 6.
Design development and performance of a solar–powered kier for single–stage cotton preparation
Authors: Gulrajani M L , Gupta Sanjay
Published: July 2010

The design and performance details of a 20 kg conventional pressure kier, integrated with a solar water–heating system is discussed. The ‘solar kier’ uses a solvent–assisted chemical formulation for carrying out simultaneous desizing, scouring and bleaching of cotton. Requisite properties, e. g. whiteness and absorbancy, were obtained with minimal strength loss. The economic advantages of the system are outlined.
A microscopical study of the pathway for diffusion of rhodamine B and octadecylrhodamine B into wool fibres*
Authors: Sideris V , Holt L A , Leaver I H
Published: July 2010

The pathways for the diffusion of the basic dyes rhodamine B and octadecylrhodamine B into wool under aqueous and non–aqueous dyeing conditions have been investigated. The distribution of each dye within the fibre at various stages of the dyeing process was monitored by fluorescence microscopy. By judicious choice of solvent system and treatment time, the dyes could be directed into different histological components of the fibre. Intercellular diffusion, involving passage of the dye through the cell membrane complex between the cortical cells, was generally the preferred route for penetration of the fibre. The distribution patterns of the two dyes differed markedly and were strongly dependent upon the solvent composition. Whilst selective staining of the cell membrane complex occurred in an anhydrous solvent system, preferential staining of that region of the cell membrane complex associated with the orthocortex resulted when the dyes were applied from aqueous alcohol systems.
The role of polyoxyethylenated stearylamines in the dyeing of cotton with direct dyes
Authors: Tsatsaroni E G , Eleftheriadis I C , Kehayoglou A H
Published: July 2010

The adsorption kinetics of two polyoxyethylenated stearylamines (PSAs) on cotton fabrics have been studied. Interactions between the PSAs and the dyes C. I. Direct Red 23 and C. I. Direct Blue 2 have been investigated and the stoichiometry of the various dye/PSA complexes formed have been deduced. Cotton fabrics, both untreated and pretreated with PSAs, have been dyed with the above dyes and greatest dye uptake was observed at higher dye/PSA molar ratios. No PSA was found to remain on the fabrics after dyeing.
Dyeing behaviour of aqueous solutions of dispersant–free disperse dyes in the high–temperature dyeing of polyester (Part 1)
Authors: Navratil Josef
Published: July 2010

High–temperature dyeing of polyester with dye dispersions and dispersant–free disperse dyes dissolved in the presence of a surfactants mixture has been simulated with the aid of both a previously developed and a new mathematical model, and the exhaustion kinetics have been computed for three dyes with the aid of experimentally determined dyeing parameters. The correctness of the models was tested by experimentally determined exhaustion curves. An equilibrium in the system consisting of a substrate, dye and surfactant mixture has been investigated experimentally as a function of the temperature and of the concentrations of the dye.
The role of vinylsulphonyl reactive dyes in prevention of wool damage
Authors: Lewis D M , Smith S M
Published: July 2010

Reactive dyes of the vinylsulphone and α‐bromoacrylamido types inhibit wool fibre degradation during dyeing. The effect is proportional to the amount of dye applied, which may be explained in terms of set inhibition and modification of the cell membrane complex. Reactive dyes are capable of interfering with the fibre thiol‐disulphide interchange reactions, as evidenced by a study of model thiol derivatives of vinylsulphone dyes. H.p.l.c. has been widely employed to separate and assist with identification of these thiol adducts. The role of the cell membrane complex has been clarified using reactive vinylsulphone fluorescent compounds as dye models and following fibre penetration using fluorescence microscopy.
A Fourier transform infra‐red spectroscopic study of wool subjected to permonosulphuric acid treatments
Authors: Coderch L , Pons R , Erra P
Published: July 2010

A study of the permonosulphuric acid wool shrinkproofing process has been carried. The aim was to determine the optimum conditions under which the oxidative and reductive steps should be performed, and effects of these steps on area shrinkage and degree of whiteness. The formation of external and internal cystine‐oxidised derivatives by FTIR was also examined. The presence of a certain amount of oxidising agent is necessary to partially oxidise the cystine, while the reducing/nucleophilic agent acts to form cysteine sulphonic acid, mainly at the fibre surface up to pH values of 8–8.5, and also at inside the fibre at higher pH values.
A numerical approach to acrylic dyeing
Authors: Abeta Sadaharu
Published: July 2010

A numerical approach to the relationship between depth of dyeing, dyeing temperature and rate of dyeing (time necessary for complete exhaustion) has been studied for the cationic dye/acrylic fibre dyeing system. A method for determining the optimum dyeing conditions from two absorption curves at two dyeing temperature levels has been developed. A calculation system based on these relationships has proved to be applicable and valuable in practical dyeing.
An intelligent approach to colour recipe prediction
Authors: Westland S. , Bishops J M , Bushnell M J , Usher A L
Published: July 2010

Imagine a recipe prediction system that can deal with fuzzy real‐world data. Imagine a system that can automatically improve its performance over time and that can adapt to changes in production variables such as water supply or colorant strength. Until recently this could only be a description of a human colourist but a new technique of recipe prediction is being developed along these lines at Reading University.
The efficiency of a non‐aqueous shrink‐resist treatment in controlling the moisture regain of wool
Authors: Erra P. , Manich A M , Solá J. , Juliá M R
Published: July 2010

The influence of several experimental conditions at different levels of wool moisture regain on wool shrink‐resist treatments with sodium methoxide in 2‐propanol have been studied. This study was carried out using a central rotatable design, in which the moisture regain, sodium methoxide concentration and treatment time were the variables and the percentage area shrinkage and degree of whiteness were the responses. The results show that the influence of sodium methoxide concentration and treatment time on shrink resistance and whiteness is dependent of moisture regain value of wool fibres. The effect of treatment temperature on sodium methoxide exhaustion, shrinkage and wetting time of knitted merino wool fabric under the same experimental conditions were also considered.
Creating wealth from textile coloration
Authors: Glover B , Collishaw P S , Hyde R F
Published: July 2010

There are many advantages in using high‐quality dyes in modern, high‐quality, reproducible processes to maximise productivity, in other words a right‐first‐time objective. The financial rewards are examined in this article, and examples are quoted. The need to consider the costs of the whole dyeing process before making or rejecting changes is stressed.
One‐bath dyeing of wool/polyester blends with acid and disperse dyes. Part 2 — disperse dye distribution on polyester and wool
Authors: Wang Jiping , Åsnes Harald
Published: July 2010

Disperse dye distribution on polyester and wool during one‐bath dyeing of wool/polyester blends is discussed. The addition of carriers increases the wool's intrinsic saturation value for disperse dye, thus raising the degree of staining on the wool component at the low dye uptakes. However, staining can be minimised if the dyeing is close to or attains equilibrium conditions. Sequestering agents can accelerate the disperse dye diffusion out of the wool fibre, further reducing staining on wool and transferring more disperse dyes from wool to polyester. Citric acid can be used as a sequestering agent as well as a pH adjusting agent.
Photomodification of the cell membrane complex of wool‐the effect on dyeability
Authors: Sideris V , Leaver IH , Holt L A , Jones L N
Published: July 2010

Wool fibres have been selectively stained in the region of the cell membrane complex with eosin Y, fluorescein and rose bengal. Dye distribution patterns were determined by fluorescence microscopy and electron‐induced X‐ray emission (in conjunction with scanning transmission electron microscopy). Irradiation of the stained fibres with visible light caused a reduction in the rate of dye uptake when the wool was subsequently treated with an aqueous solution of the dye CI Acid Red 18. The change in the dyeability of wool was attributed to selective photomodification of the cell membrane complex.
The addition of reactive compounds to nonreactive dyebaths. Part 5‐procedure for obtaining reactive dyeings on cotton
Authors: Kamel Magda M , Kamel M M , Kamel M
Published: July 2010

An easy procedure for the preparation of solutions containing certain types of reactive dye and their subsequent application on cotton is described. This procedure takes advantage of the expected high reactivity of these dyes, which have adjacent hydroxy and amino groups in the molecule, and strives to evade the problems usually associated with the preparation and application of such dyes in the solid form. Several factors that affect the colour strength of reactive dyeings thus obtained are investigated. Possible disadvantages when applying this procedure are discussed.
The environmental cost of processing cotton
Authors: Lockett Peter
Published: July 2010

For generations Lancashire has been synonomous with the cotton processing industry. Cheap fuel and a plentiful supply of high‐quality water has been the foundation for numerous success stories. However, years of production have left its mark on the environment and the industry today has been left to pay the bill. Peter Lockett highlights current problems facing cotton processors.
The manufacturer's perspective
Authors: Condon Brian
Published: July 2010

A common complaint of many dyers and finishers is that they are often called upon to perform technical miracles for retailers and designers. Exclusion from the garment design stage means that they spend most of their time solving problems rather than offering advice. Brian Condon highlights some of the difficulties facing dyers and finishers of lace.
The retailer's perspective
Authors: Winfield Tony
Published: July 2010

As the last stop in the supply chain, retailers are in direct contact with the most important customer base: the man and woman in the street. Subsequently, they possess a detailed knowledge of the market and sophisticated concepts have emerged as a means of targeting potential customers. Tony Winfield suggests that manufacturers would benefit if they thought in terms of the same market segments.
What retailers will want
Authors: Lewis Chris
Published: July 2010

It is claimed that customers today are more sophisticated. If the retailer is unable to meet their requirements they will vote with their feet. Consequently, retailers are now looking for more flexible and efficient suppliers who can produce quality goods with speed. Chris Lewis outlines the criteria on Marks and Spencer's agenda for the 1990s.
Some studies in degumming of silk with organic acids
Authors: Gulrajanid M L , Sethi Sheetal , Gupta Sanjay
Published: July 2010

Two types of silk substrate have been examined and optimum conditions for degumming with tartaric acid determined. The experiments have been carried out according to the Box and Behnken response surface design. The degumming action often other organic acids has also been evaluated.
Afterchrome dyeing of wool. Part A — chromium in the effluent, analytical determination and characterisation of influencing factors
Authors: Thomas H , Kaufmann R , Peters R , Höcker H , Lipp M , Goschnick J , Ache H J
Published: July 2010

As a consequence of increasing legal restrictions on the concentration of chromium in industrial discharges, afterchrome dyeing of wool has been re‐evaluated. Special regard was given to the distribution of trivalent and hexavalent chromium species in the individual process stages (chroming, rinsing and ammonia aftertreatment baths) of afterchrome dyeing. Recommendations are outlined to give minimum chrome residues in the effluent and to avoid the distribution of the toxic hexavalent chromium species into the environment. The effiency of the thiosulphate procedure is doubtful for improving the exhaustion of total chromium. Subsequent alkaline treatments of chrome‐dyed wool lead to a desorption of chromium compounds that are probably fibre‐bonded chromium—tetrathionate (sodium thiosulphate) complexes.
The role of laboratory dyeing machine design in achieving accurate colour matching for bulk
Authors: Smith Stuart S
Published: July 2010

Historically the demands of industry have stimulated technological developments in laboratory machinery design. During the last two decades laboratory machine manufacturers have produced equipment capable of simulating all production process machine parameters. Development of new process technology lies largely in the hands of chemists and physicists, and it is inconceivable that engineers will be unable to meet their future demands. Along with the expansion of integration dyeing, recent work in mathematical modelling and dye process control has suggested a requirement for liquor flow control. Equipment to satisfy this need is already available, some of which can determine optimum processing conditions.
Low‐chrome dyeing.
Authors: Xing Jianwei , Pailthorpe M T
Published: July 2010

The effect of a rare earth chloride mixture on the reduction of chromium residues in chrome dyebath effluents has been investigated. Chelation between the rare earth cations and chrome dyes took place and level chroming results were obtained even when reduced quantities of dichromate were used in the afterchroming stage. An explanation of these effects is given based on an ion exchange between the trivalent chromium and the rare earth cations during the afterchroming stage. A significant reduction in chromium residues in the dyebath was observed due primarily to the reduction in dichromate addition. The colour of the ‘rare earth’ dyed wool was similar to that of conventionally afterchrome dyed wool. The colour fastness properties of the ‘rare earth’ dyeings were not adversely affected and wool damage was slightly reduced.
Wool bleaching with reducers in the presence of sodium laurylsulphate. Part 4 — treatments to remove the surfactant absorbed by wool
Authors: Gacen J , Cegarra J , Caro M
Published: July 2010

Treatments applied to remove the sodium laurylsulphate from wool bleached with thiourea dioxide in the presence of this surfactant cause a slight decrease of wool whiteness. However, whiteness remains far better than that of wool bleached without such a surfactant.
Preparation procedures for woven cotton and polyester/cotton fabric. Part 1 — enzymatic desizing
Authors: Levene R , Prozan R
Published: July 2010

Factors influencing the enzymatic desizing of woven cotton and polyester/cotton fabric have been examined using a medium‐temperature‐stable enzyme or one with high thermal stability. The effect of variation in time, temperature and concentration on degree of desizing, fabric absorbency before bleaching, whiteness and degree of desizing after bleaching were assessed by regression analysis on the results of statistically designed experiments. The dominant factors were temperature and time, while variation in concentration often had no significant effect. The results show that more than brief treatment with a high‐temperature enzyme has a negative influence on final whiteness. The polyester/cotton fabric, sized with a mixture of starch and poly(vinyl alcohol), was poorly desized by the medium‐temperature enzyme, but after bleaching desizing was adequate. Improved correlations for absorbency were obtained using a logarithmic absorbency index.
Methylated derivatives of 1,5‐diamino‐4,8‐dihydroxyanthraquinone and 1,8‐diamino‐4,5‐dihydroxyanthraquinone — blue dyes for synthetic‐polymer fibres
Authors: Peters A T , Ma Xisai
Published: July 2010

The synthesis of a series of /V‐methylated derivatives of 4,5‐diamino‐1,8‐dihydroxyanthraquinone (DACZ) and of 4,8‐diamino‐1,5‐dihydroxyanthraquinone (DAAR) is described. All possible N‐methyl derivatives of DAAR were obtained, but the tetramethylated derivative of DACZ could not be isolated. Attempts to synthesise an assymetrical NN‐dimethyl derivative of DACZ were also unsuccessful, only an NO‐dimethylated derivative being obtained. The colour of the dyes is discussed in relation to the degree of methylation, and solvent effects on absorption maxima are also reported.
The microfibre step change
Authors: Leadbetter Peter , Dervan Stephen
Published: July 2010

Over recent decades there has been a trend towards finer filaments that have novel aesthetic and tactile qualities. The rate at which this trend continues will, at least in part, be influenced by new dye developments and improved coloration techniques. Peter Leadbetter and Stephen Dervan discuss the emergence of polyester microfibres and the increased demands placed on the dyes that colour them.
Preparation procedures for woven cotton and polyester/cotton fabric. Part 2 — oxidative desizing with hydrogen peroxide
Authors: Levene R , Prozan R
Published: July 2010

Oxidative desizing with sodium hydroxide in the presence of hydrogen peroxide has been investigated as a preparatory treatment for dyeing and printing cotton and polyester/cotton woven fabric. Using statistically designed experiments, the effect of time and temperature of treatment, and peroxide and sodium hydroxide concentrations on degree of desizing, whiteness, fabric absorbency and mote removal has been determined. The major factor determining desizing rate was sodium hydroxide concentration. As peroxide concentrations increased above 0.1% o.w.f. of 35% solution desizing was retarded. Desizing was thus seen to be a hydrolytic process initiated by hydrogen peroxide. Whiteness achieved during desizing was not correlated with sodium hydroxide concentration and adequate whiteness was not achieved with the 100% cotton fabric. Whiteness of the blend was significantly influenced by all the desizing factors, while absorbency was affected by treatment time and temperature. Pure cotton was not rendered absorbent at all at below 65°C, in contrast with enzymatic desizing. Treatment for a short time in the temperature range 65–95°C gave a generally unsatisfactory level of mote removal.
Improving the compatibility of disperse dye mixtures using levelling agent — assessment through colour coordinates
Authors: Shukla S R , Dhuri S S
Published: July 2010

The addition of a nonionic levelling agent to a dyebath containing a mixture of three disperse dyes in equal proportions and having similar hues (all in the red—yellow sector of colour space) significantly improved their compatibility, especially at higher applied depths of 3.0% and 4.5%. The dyed samples were measured for the differences in their colour coordinates with respect to the undyed substrate on a spectrophotometer attached to an IBM personal computer. The plots of ΔL* vs ΔC*ab, ΔL* vs K/S, Δb* vs Δa*, Δa* vs K/S and Δ6* vs K/S clearly indicated the improvement in compatibility of the dye mixture.
Revival of natural dyes in Asia
Authors: IshratAli Syed
Published: July 2010

Increasing environmental awareness has persuaded some of the major Asian countries to reassess the feasibility of natural colorants. As one of the most agriculturally rich regions of the world, the emphasis has been on finding new colour sources which have the potential to yield high quality dyes. Syed Ishrat Ali argues that a detailed programme of R & D into the capabilities of natural dyes is of vital importance.
Removing colour from dyehouse waste waters — a critical review of technology available
Authors: Cooper P
Published: July 2010

Strict controls are being introduced on coloured effluents from UK dyehouses discharged to sewer. Failure to comply with these new regulations could result in prosecution. Yet in certain cases the technology to treat dyehouse waste waters adequately is either not available or prohibitively costly. This paper (originally given at a conference at the Manchester Conference Centre entitled ‘Waste water management for industry’) reviews the treatment technologies that can currently be used by the textile processor and discusses those newer techniques that may emerge in the near future.
The effect of dyeing on the hygral expansion of worsted fabrics — Part 1
Authors: Dodd K J , Carr C M , Baird M
Published: July 2010

The influence of dyebath pH, dyeing time, levelling agents, dyestuff and anti‐setting agent on hygral expansion has been investigated. The incorporation of an anti‐setting agent in the dyebath minimised increases in hygral expansion resulting from the dyeing process.
Synthetic reflectance curves by subtractive colour mixing
Authors: Hawkyard C J
Published: July 2010

An algorithm has been developed, using the subtractive primaries, that enables a ‘synthetic reflectance curve’ to be calculated for any set of XYZ values. A wide range of reflectance data for cyan, magenta and yellow primaries and white substrate can be used as data for the algorithm, provided the curves are smooth and correspond to those colours. These synthetic reflectance curves can be used as replacements for the data from measured physical standards for match prediction purposes. The synthetic standards have good colour constancy under a range of illuminants. They have been used to speed up the generation of fashion shade ranges selected initially on a CAD system.
The effect of washing and heat treatment on the surface characteristics of fluorocarbon resin‐treated polyester
Authors: Wakida Tomiji , Li Huishun , Sato Yukihiro , Kawamura Haruo , Ueda Mitsuo , Mizushima Haruo , Takekoshi Shoji
Published: July 2010

Polyester fabrics and films treated with two fluorocarbon resins were washed and heat treated. Water repellency, surface tension and ESCA measurements were carried out. Changes in the water repellency of the resin‐treated polyester fabric caused by washing and heat treatment are related to modification of the chemical composition of the polyester surface.
Wool bleaching with reducing agents in the presence of sodium lauryl sulphate. Part 5 — bleaching with sodium bisulphite
Authors: Gacén J , Cegarra J , Caro M , Cayuela D
Published: July 2010

Wool bleaching with sodium bisulphite in the presence of sodium lauryl sulphate has been shown to improve wool whiteness by four Berger units. A 25% decrease in cysteine content is also obtained as a consequence of the protective action of the surfactant on the keratin's disulphide linkage.
The quantification of small visual colour differences
Authors: Hayden Sarah L , Oulton David P
Published: July 2010

The Shademaster system, developed at UMIST, was used to explore the use of on‐screen colour in order to assess the reliability of the CMC(l:c) formula as a measurement of small colour differences. Differences limited to almost pure hue, chroma and lightness changes around nine colour centres were judged by a group of ten observers. Each colour difference pair was presented on‐screen in the form of a divided tile. The colour difference between each pair was measured using a Bentham telespectroradiometer and by a method using reverse transformation of RGB to CIE coordinates. The resultant measurements were used to determine the visibility of a particular colour difference, how that visibility varied from colour to colour and how it varied in different directions (i.e. hue, chroma or lightness). The data obtained from the judgements were used to construct perceptibility boundaries around each colour centre.
Formaldehyde in textiles
Authors: Hewson Mike
Published: July 2010

A large amount of formaldehyde is used in the textile industry, particularly for imparting a crease‐resist finish to fabrics. Recently concern has been expressed about its health risks. Mike Hewson looks at how the quantity of free formaldehyde and other potential irritant derivatives present on a fabric can be assessed.
New control strategies for batch dyeing operations using mathematical modelling and simulation
Authors: Flower John , Burley Roger , Nobbs Jim
Published: July 2010

Around 60% of all dyed fibre and yarn is produced in package dyeing machines. It is therefore important to look at their design and operation in the light of the experience of similar processes in the chemical and process industries. This article tries to merge current research ideas on the dynamic on‐line control of package dyeing machinery with practical observations and industrial experience.
FT Raman spectroscopic studies of wool
Authors: Hogg L J , Edwards H G M , Farwell D W , Peters A T
Published: July 2010

FT Raman spectroscopy has been used to investigate the structure of scoured wool cloth and fibres subjected to hydrogen peroxide bleaching. The advantages of FT Raman spectroscopy over conventional laser Raman and IR spectroscopic techniques are discussed. The spectra obtained are more highly resolved than have previously been presented; clear structural features are observed between 400–3400 cm‐1 and assignments made of the vibrational modes. The results show that FT Raman spectroscopy can show structural changes in the fibre that are caused by treatments to which the fibre has been subjected, such as bleaching.
Is carthamine a single component?
Authors: Saito Koshi
Published: July 2010

A chromatographically pure sample of red pigment from dyer's saffron (Carthamus tinctorius L) was separated into two distinct reddish components on an insoluble polyvinyl polypyrrolidone column, developed with acetone/methanol/water. These components were isolated, purified and subjected to the analytical processes. Using standard analytical techniques, only slight differences could be detected between the two types of carthamine. However, a marked difference was displayed by optical rotary dispersion spectroscopy of the two samples. This provides evidence for the existence of two geometrical isomers of carthamine.
Level fast dyeing of wool with nucleophilic aminoalkyl dyes and crosslinking agents.
Authors: Lewis D M , Wang Y‐N , Lei X‐P
Published: July 2010

Aminoethylaminotriazinyl dyes prepared from available chlorotriazinyl dyes have been applied to wool in the form of non‐reactive levelling acid dyes. The nucleophilic pendant amino residue readily underwent crosslinking reactions with wool, using suitable crosslinking reagents to give level dyeings of high wet fastness.
The influence of liquor ratio on the jet dyeing of cellulose fibres using different types of monochlorotriazine reactive dyes
Authors: Gorensek M. , Gaber V. , Peternelj N. , Vrhunc V.
Published: July 2010

The exhaustion and fixation of four commercial monochlorotriazine reactive dyes on cotton fabric has been determined spectrophotometrically in the all‐in jet dyeing process. The influence of liquor ratio on exhaustion and fixation was estimated. The exhaustion of two dyes on the cotton fabric was very good, especially at short liquor ratios. High levels of fixation at all liquor ratios were recorded, varying to some extent according to the liquor ratio used in the dyeing cycles.
Phosphatidylcholine/cholesterol liposomes as vehicles for anthraquinone disperse dyes in wool dyeing
Authors: de la Maza A. , Parra J L , Coderch L. , Bosch P.
Published: July 2010

The use of liposomes containing increasing amounts of cholesterol as carriers for anthraquinone disperse dyes in the dyeing of wool fibres is described. Multilamellar lipid vesicles of egg phosphatidylcholine and containing CI Disperse Violet 1 at different phosphatidylcholine‐cholesterol relative concentrations were used. Controlled exhaustion of dye on the wool was achieved, which was directly dependent on the liposome lipid concentration. Increasing the amount of cholesterol in the bilayers resulted in a decrease in dyebath exhaustion while improving the total amount of dye bonded to the wool fibres. The dye's dispersion efficiency was also improved, compared with the use of conventional dispersing agents. The optimum application of these systems, both in terms of dyebath exhaustion and total amount of dye bonded to the wool samples, was directly correlated with the dye/lipid weight ratio for the maximum level of dye encapsulation efficiency.
A novel approach for improving the light fastness of crystal violet lactone
Authors: Oda Hironori
Published: July 2010

Colour formers are important as functional dyes for imaging and data recording systems. Metal complexes of substituted arylsulphonic acids or arylcarboxylic acids have been synthesised to prolong the life of coloured species derived from crystal violet lactone. The suppressing effect of these compounds towards photofading was investigated on cellulose. It was found that zinc and nickel salts of 2,6‐dihydroxybenzoic acid and its derivatives can be applied as effective stabilisers against the fading of crystal violet lactone. The protecting effect of phenyl esters against fading was also examined.
Colour measurement by video camera
Authors: Connolly Christine , Leung William , Nobbs Jim
Published: July 2010

If video cameras could be used to measure colours directly, many technical and commercial possibilities would opened up. Christine Connolly, William Leung and Jim Nobbs describe how this is now close to being a reality.
Determined to survive‐and succeed
Authors: Houlton Sarah
Published: July 2010

Merlin Dyeing and Finishing is a very unusual textile company‐not least because it is owned and run by a woman with no textile background. Sarah Houlton went to investigate the story behind its success.
The effect of sputter etching on the surface characteristics of dyed aramid fabrics
Authors: Kobayashi Shigenobu , Wakida Tomiji , Niu Shouhua , Hazama Satoshi , Ito Taisuke , Sasaki Yoshiyuki
Published: July 2010

Three kinds of aramid fabrics, Technora (modified p‐aramid), Conex (m‐aramid) and Kevlar (p‐aramid), were subjected to sputter etching and argon low‐temperature plasma treatments after dyeing in black with disperse dyes. The depth of shade increased considerably on Technora and Kevlar with the sputter etching treatment, but not on Conex fabrics. Argon low‐temperature plasma treatment had virtually no effect on the depth of shade on the aramid fabrics.
Change in colour of dyed aramid fabrics by sputter etching
Authors: Kobayashi Shigenobu , Wakida Tomiji , Niu Shouhua , Hazama Satoshi , Doi Chizuko , Sasakit Yoshiyuki
Published: July 2010

The aramid fabrics Technora and Conex, dyed with CI Disperse Yellow 54, CI Disperse Red 60 and CI Disperse Blue 56, were treated with sputter etching and argon low‐temperature plasma. The colour depth of Technora was considerably increased by sputter etching, whereas that of Conex was not. Changes in colour were investigated by the L*, C*, h colour system. The increase in colour depth due to sputter etching was greatly dependent on the decrease of metric lightness L* and the increase of metric chroma C*.
Dyeing properties of cotton fibres treated with liquid ammonia
Authors: Wakida Tomiji , Lee Muncheul , Niu Shouhua , Yanai Yuichi , Yoshioka Hiromu , Kobayashi Shigenobu , Bae Soyeung , Kim Kyunghwan
Published: July 2010

Both scoured and sodium hydroxide mercerised cotton fibres have been treated with liquid ammonia atndash33.4°C using commercial operating equipment and then the ammonia removed at 130°C in a hot drum. The moisture regain and water absorbency of the fibres treated with liquid ammonia were increased compared with values on untreated fibres, whereas both these parameters on mercerised cotton fibres were decreased by subsequent liquid ammonia treatment. The fibres were dyed with CI Direct Red 2 and CI Direct Blue 1. Liquid ammonia treatment of the scoured cotton fibres increased the rate of dyeing, equilibrium dye adsorption, standard affinity, heat of dyeing and change of entropy, while the dyeing properties of mercerised cotton were adversely affected by subsequent liquid ammonia treatment.
Waste water treatment‐choosing the right membrane system
Authors: Aurich Christoph W
Published: July 2010

In the environmentally responsible textile industry of the 1990s, the emphasis in effluent treatment has shifted from shortcut dilution methods to long‐term solutions, such as reducing pollutant sources, concentrating and removing polluting elements and reusing process water. Molecular filtration can help solve these problems, but the correct selection of a membrane system is vital, writes Christoph W Aurich.