A classification system to enhance light‐fastness data interpretation based on microfading tests and rate of colour change

In general light‐fastness tests are carried out by comparing the colour change of a sample to the colour change of Blue Wool Standards in the same illumination conditions. With the microfading technique, developed to test the light fastness of a tiny test area on objects of cultural value, this comparison is made by absolute colour change after exposure. This article presents a new approach to enhance data interpretation of light‐fastness tests by the use of the rate of colour change. The procedure is combined with the conventional classification process using absolute colour change. The new classification system with the rate of colour change was applied to 44 samples, 13 of them were classified in more sensitive Blue Wool categories when analysing the rate of colour change. The perspective of rate of colour change helps to enhance data interpretation especially of samples showing fading characteristics different from the light‐fastness standards.     

Wavelength sensitivity of AATCC Blue wool lightfastness standards under light radiation

The fading characteristics of the AATCC Blue Wool L2 and L4 lightfastness standards were examined from the standpoint of wavelength sensitivity. Experiments were carried out by exposing a specimen to a narrow monochromatic band isolated from the dispersed polychromatic light emitted by a Xe lamp source. The wavelength sensitivity characteristics of Blue wool L2 and L4 lightfastness were determined on a radiant energy basis. Both Blue Wool Standards displayed peak maxima at 245 and 294 nm. The results indicated that UVA and UVB had a significant fading effect, whereas visible light caused fading to a small extent. Specific wavelengths caused Blue wool to significantly fade, suggesting that the total irradiated UV energy may not be an appropriate index. In addition, their spectral reflectances did not directly explain these characteristics of the standards.     

Fading characteristics of a disperse dye on cellulose triacetate, polyester and nylon under monochromatic light radiation

Light fastness of CI Disperse Blue 165 dye on cellulose triacetate, polyester and nylon fabric substrates exposed to monochromatic light was examined on a radiant energy basis. The action spectra indicated a strong effect on the substrate-fading characteristics: nylon exhibited poorer light fastness in the visible and ultraviolet light range than polyester and cellulose triacetate. Two specific fading peaks were found for the nylon substrate, which were different to those found for the polyester and cellulose substrates. It was shown that polyester exhibited the best light fastness properties overall. The colour changes in the fading process suggested that the fading products of the dye on nylon (where reduction occurred) were different from those on the polyester and cellulose triacetate substrates (where oxidation occurred).     

Quaternary reactive dyes containing a thioether‐ethylsulphone group. Part 2; Application methods for the dyeing of nylon†

A member of the new series of cationic reactive dyes containing a thioether‐ethylsulphone grouping referred to in Part 1 of this series has been applied to nylon at pH 3–10. The dye is water soluble and shows excellent substantivity for nylon 6.6 when dyed at the boil at pH 8–10. Under alkaline conditions, gradual β‐elimination back to the vinylsulphone dye occurs and covalent bond formation quickly takes place with the fibre; the higher the pH the more rapidly this occurs. Dyeings carried out at pH 10 showed very good brightness and levelling, together with good wash fastness. The light fastness of dyeings at moderate depth was 4–5 on the Blue Wool scale.     

Dyeing and deodorizing properties of cotton,silk, wool fabrics dyed with Amur Corktree,Dryopteris crassirhizoma,Chrysanthemum boreale,Artemisia extracts

This study used four kinds of natural colorant solutions extracted from Amur Corktree, Dryopteris crassirhizoma, Chrysanthemum boreale, Artemisia using water at 90°C for 90 min with a liquor ratio (solid natural colorant material/solvent water, weight ratio) of 1/10. The dyeing, color fastness, deodorizing properties of cotton, silk, wool fabrics dyed with natural colorant extracts were compared. These properties were found to be significantly dependent on the extract concentration, colorant structure, fabric type. Color fastness (light, water, perspiration fastness) ranged between second and fifth grades and deodorizing performance of fabrics dyed with various natural colorant extracts between 34 and 99%. It is worth noting that the use of natural colorants notably enhanced the deodorizing performance. Wool fabrics showed the highest performance increase at 98–99%, followed by silk and cotton. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Development and application of a mathematical model to explain fading rate inconsistencies observed in light‐sensitive materials

Light fastness tests conducted on several areas of a light‐sensitive material may sometimes show inconsistent fading rates. These different fading behaviours suggest that colorants are not evenly distributed over the substrate surface or may be attributed to texture variations of the material. A mathematical model has been developed to help explain these discrepancies. Micro‐fade testing, a relatively novel technique, has allowed microspectroscopic detection of variations in the initial colour parameters of a sample, permitting assessment of its diverging fading rates. The method has been applied to fading data of various light‐sensitive materials resulting in more consistent fading patterns. It has been demonstrated that micro‐fading curves obtained for the same material are related by a constant value, which is the ratio of adjusted values of time and ΔE*.     

蚕蛹蛋白纤维混纺纱染色效果影响因素分析

为迎合市场对蚕蛹蛋白纤维应用的需求,对蚕蛹蛋白纤维和天丝混纺纱进行了染色性能测试分析。以上染率及K/S值作为衡量指标,对上染后的蚕蛹蛋白纤维混纺纱进行上染效果评估。通过综合考虑,确定最佳染色工艺如下:1%(o.m.f.)的活性蓝M-2GE染料,浴比1∶20,平平加O质量浓度为0.5 g/L,硫酸钠质量浓度为25 g/L,碳酸钠质量浓度为15 g/L,上染温度和时间分别为65℃和45 min,固色温度和时间分别为70℃和35 min。经最优工艺染色后,蚕蛹蛋白纤维针织面料染色牢度较好,符合染色质量要求。     

Synthesis and application of a novel,triphendioxazine‐based,phosphorus‐containing acid dye for wool

A novel phosphorus‐containing acid dye based on triphendioxazine was designed and synthesised from diphenylamine through a series of reactions. The dye has a navy‐blue colour, high molar extinction coefficient of 5.32 × 10⁴ l/mol·cm, and high substantivity for dyeing wool in a salt‐free, aqueous dyebath. A high exhaustion value of 98.2% on wool fabrics was recorded at 3% omf and a liquor ratio of 1:20. The wash fastness values of the acid dye, including colour change and staining on cotton and wool, were grades 5, 4 and 4–5, respectively. The dry and wet fastness are grades 4–5 and 4, respectively. In addition, light fastness reaches grades 6–7 at 3% omf dye concentration. These dye properties are better than those of commercial triphendioxazine dyes, for example, CI Direct Blue 106 and CI Reactive Blue 198, under analogous dyeing conditions.     

Modification of wool fabric using ecologically acceptable UV‐assisted treatments

Wool fabric was modified using ecologically acceptable treatments in order to enhance its shrinkage and pilling resistance. Wool fabrics were irradiated with ultraviolet light for different period of times. The UV‐irradiated wool fabrics were then treated with an oxidising agent (hydrogen peroxide or sodium monoperoxyphthalate) or a protease enzyme (papain or savinase 16L type EX). Treatment of wool fabric with these systems was found to be effective in reducing its pilling and shrinkage without severe loss in weight and strength of the fabric. Chemical and mechanical analyses of the treated samples compared with the untreated one are reported. Transmission electron microscopy investigation of the untreated and treated wool samples was used to identify the histological component in wool keratin affected by these treatments. Copyright © 2005 Society of Chemical Industry     

Dispersant‐free dyeing of poly(lactic acid) fabric with temporarily solubilised disperse dyes from azopyridone derivatives

Poly(lactic acid) fibre is derived from annually renewable crops and known to be 100% compostable. In order to extend its environmental friendliness into the dyeing process, dispersant‐free dyeing of poly(lactic acid) fabric with three temporarily solubilised azo disperse dyes based on hydroxypyridone moiety containing a β‐sulphatoethylsulphonyl group was investigated. The dyes were successfully applied to poly(lactic acid) fabric without the use of dispersants. The colour yields of the dyes on poly(lactic acid) fabric were observed to be dependent on dyebath pH and dyeing temperature. The optimum results were obtained at pH 4–5 and 110 °C. One of the dyes showed a colour yield as good as that of a commercial disperse dye and good build‐up on poly(lactic acid) fabric. All of the dyes could be alkali cleared owing to ionisation of the dye under mild alkaline conditions. Wash fastness was good to very good, and light fastness was good. The chemical oxygen demand levels of the poly(lactic acid) dyeing effluent from the dyes were considerably lower than those from a commercial disperse dye.     

Light fastness of naturally occurring anthraquinone dyes on nylon

Nylon fabric has been dyed with two purified components of Indian madder, purpurin (1,2,4-trihydroxyanthraquinone) and munjistin (1,3-dihydroxy-2-carboxyanthraquinone). The light and wash fastness of dyed and mordanted samples has been studied. Purpurin showed much better resistance to photofading than munjistin. It was found that the type of mordant and the method of mordanting significantly affected the rate and extent of photofading. The use of copper or ferrous sulphate gave high resistance to fading, whereas stannous chloride or alum did not. On the other hand, light fastness was improved when postmordanting was conducted with copper or ferrous iron, but pre-mordanting was superior in the case of stannous chloride or alum.     

Synthesis and salt‐free dyeing characteristics of cationic reactive dyes containing polyetheramine segments

A series of cationic reactive dyes containing both quaternary ammonium and polyetheramine as soluble groups and monochlorotriazine as a reactive group have been synthesised and applied to cellulose fibre by salt‐free exhaust dyeing. Investigation of the synthesis method and dyeing properties of these cationic reactive dyes showed that the best pH value for these dyes is 6, and also that these cationic reactive dyes give a high substantivity to cellulose. In the salt‐free dyeing process, their adsorption was consistent with the Langmuir isotherm during the primary exhaustion stage, but in the secondary exhaustion stage the adsorption was in accordance with the Freundlich isotherm, and their secondary exhaustion reached up to 96% and above. Moreover, the degree of fixation, the levelling, and the transfer properties on cotton fabric were good. Light fastness reached grade 5–6, washing, perspiration, and dry rubbing fastness reached grade 4 and above, but wet rubbing fastness reached only grade 3–4.     

Improving light fastness of natural dyes on cotton yarn

The objectives of this study were to evaluate the light fastness of selected natural dyes (madder, weld and woad) and the effect of some commonly used antioxidants and UV absorbers on the light fastness of these dyes.

The photofading rate curves of madder and weld fixed on cotton correspond to type II fading rate curves described by Giles. These results are in concordance with those of Cox-Crews. The woad presents a type III fading rate curve, similar to the indigo fading rate curve presented by Cox-Crews.

A poor light fastness of the three natural dyes in comparison with synthetic ones is established beyond question. Nevertheless, the use of some additives can improve this default of natural dyes. In all the cases, the use of UV absorbers or antioxidants improved the light fastness of dyed fabrics. The most effectives were the vitamin C and the gallic acid.     

阳离子改性棉织物活性染料染色性能

用自制的阳离子改性剂对棉织物进行改性处理,用浓度为6%(o.w.f.)的活性红3BS、活性黄3RS、活性黑KN-B三种染料分别对改性后的棉织物进行无盐染色。分别讨论了上染速率曲线、移染性能对上染性能的影响。得到的最优固色工艺为:碳酸钠用量为10 g/L~15 g/L,在60℃下固色20分钟~30分钟。改性棉织物的匀染性良好,耐水洗色牢度和耐摩擦色牢度与常规染色基本一致。     

The effect of humidity, fabric surface geometry and dye type on the colour of cotton fabrics dyed with a select range of anionic dyes

Four C.I. Solubilised Sulphur dyes were applied to cultivated silk fabric using sodium thioglycolate at pH 7, for 30 min at 60 °C in the absence of electrolyte. Medium/deep shades were obtained that displayed good/excellent fastness to washing at 40 °C and little or no sensitivity to oxygen bleach fading. The dry rub fastness of the dyeings ranged from moderate to good whilst the wet rub fastness varied from poor to moderate; light fastness of the 10% omf dyeings varied from low to moderate. The mild application conditions used had little effect on the tensile strength of the fabric.     

Improvement of light fastness of natural dye: effect of ultraviolet absorbers containing benzotriazolyl moiety on the photofading of red carthamin

While the contribution of ultraviolet absorbers to synthetic dyes has been investigated by several workers, there have been few studies pertaining to the use of functional ultraviolet absorbers as a means of improving the light fastness of natural dyes. In this paper, numerous potential ultraviolet absorbers were prepared to prolong the life of natural dye carthamin. The effects of these compounds in reducing photofading were examined on a polymer substrate. The use of commercial ultraviolet absorbers was not necessarily useful in improving the light fastness of the colour. However, benzophenone‐type ultraviolet absorbers containing a built‐in ultraviolet absorber moiety markedly retarded the photofading rate. It is proposed that 2,2′,4,4′‐tetrahydroxy‐5‐methylbenzotriazolylbenzophenone and its derivatives may be used as effective stabilisers in the fading of natural dyes.     

Differential dyeing of wool fabric with metal‐complex dyes after ultraviolet irradiation

Experiments were conducted to investigate the ultraviolet irradiation of wool fabric as a pretreatment for differential dyeing. Wool fabric was irradiated using a medium‐pressure mercury lamp in order to obtain, on the irradiated area, increased dye uptake under the same dyeing conditions as untreated wool. The chemical modification of the fibre surface as a result of ultraviolet irradiation was confirmed by an increase in metal ion absorption and hydrophilicity, in agreement with Fourier Transform‐infrared–attenuated total reflectance spectra, although scanning electron microscopy showed that the fibre morphology was unaffected. A selection of 1:1 metal‐complex dyes was used to show the maximum colour difference between irradiated and untreated areas of the fabric. The experiments focused on two effects: a double face with the same shade but different depths (greater depth on the treated side), and a double face with different shades. The latter effect was achieved by dyeing the irradiated fabrics with mixtures of acid and metal‐complex dyes. Rubbing and washing fastness evaluations at 50 °C confirmed that the dyeings after irradiation with the selected 1:1 metal‐complex dyes scored identically to conventional dyeings.     

Investigation into the sequential application of cationic/anionic fixing agents to improve the oxidative washing resistance of CI Leuco Sulphur Black 1‐dyed cotton fabric

Sulphur‐dyed cellulosic textiles are susceptible to washing powders containing activated peracid formulations resulting in obvious fading during repeated laundering. This study presents a novel one‐bath/two‐stage exhaust finishing process to improve the oxidative wash fastness of CI Leuco Sulphur Black 1‐dyed cotton fabric. The effect of the combined Tinofix ECO and Bayprotect Cl after‐treatment was to impart better colour fastness to oxidative International Organisation for Standardisation (ISO) 105 CO9 washing of the dyed cotton compared with those dyed fabrics after‐treated with Tinofix ECO alone. In addition, while the dyed fabrics rub and light fastness performances were unchanged by the after‐treatments, some improvement in the tensile strength of the combined Tinofix ECO and Bayprotect Cl after‐treated fabrics was observed.     

A route from olive oil production to natural dyeing: valorisation of prina (crude olive cake) as a novel dye source

An attempt has been made to valorise an agroindustrial solid waste in natural textile dyeing as a novel dye source. The dyeing and fastness properties of prina (crude olive cake/pomace) extract were evaluated to fill the gap in this field. This very cheap biomass was utilised (80 g/l) by applying chemical solvent‐free aqueous extraction to dye wool fabric with only small amounts (0.2, 0.4, 0.8, and 1.6 g/l) of metallic mordants, namely alum, iron(II) sulfate, copper(II) sulfate, stannous chloride, and potassium dichromate, and avoiding the use of alkali, acid, chemicals, and auxiliaries in dyeing and washing processes. Colour shades of beige, cream, sandy, apricot, straw, cumin, mustard, olive, and khaki were obtained. Significant differences in colour strength and CIELab coordinates were observed, depending on mordant type and mordanting method. Copper(II) sulfate and iron(II) sulfate ensured the most significant colour changes and nuances, the darkest colours, and the best light fastness values. Prina extract itself (without mordant) has a light fastness of 3 (fair) and excellent wash fastness of 4–5, both for colour change and bleeding. Irrespective of the concentration and mordanting method, alum, stannous chloride, and potassium dichromate did not generate a light fastness improvement compared with the control sample. Although good light and wash fastness values have been achieved without mordants, it is necessary to use them to widen the colour gamut and to obtain increased colour strength.     

The effects of residual surfactants on the dyeing of wool

Wool fabric was extracted with various organic solvents at their boiling points and then dyed with Coomassie Blue BL200. Non–dyed areas of fabric were observed after extraction with ethanol, acetone/ water (70:30) and chloroform/methanol (70:30) mixtures, but not after extraction with perchloroethylene. Silica column chromatography separated the extracts from various solvent pretreatments into five major peaks, based on mass obtained. Some of these peaks were shown to contain cholesterol, non–ionic surfactant and phospholipid. Up to 14 components were detected by two–dimensional thin layer chromatography of the extracts. Thin layer chromatography revealed that some of the more polar components were not extracted by perchloroethylene. Separation of the extracts by column chromatography enabled a study of dye uptake to be carried out after recontamination of pretreated fabric with the major fractions. Materials in two of these fractions were found to eliminate the uneven dyeing observed with Coomassie Blue BL200. Column chromatography and spot tests showed that they behaved similarly to the non–ionic surfactant Antarox CO 630. These experiments also showed that refluxing perchloroethylene extracted only about half as much non–ionic surfactant as did refluxing chloroform/methanol (70:30) mixture. The residual surfactant may originate from the scouring process and/or from processing oils such as Mulrex.