Effect of the water content of padded cotton fabrics on reactive dye fixation in the pad-steam process

A series of padded cotton fabrics with various water contents were obtained through vacuum dehydration. The effects of the water content on the fabric temperature variation during steaming, the colour properties, and the dye fixation rate (%F) were investigated. Dye distribution in the dyed cotton fibres was assessed. The influences of steaming time and sodium carbonate concentration on K/S value and %F of the dyed fabrics with low water content were also evaluated. The results indicate that reducing the water content of the padded cotton fabric to around 25.0% prior to steaming was favoured for reactive dyeing. The temperature of the wet fabric rose rapidly, the K/S value and %F were enhanced, and in addition the dye penetration into the dyed cotton fibres was sufficient. However, for padded fabrics with extraordinarily low and high water contents (e.g. 1.4% and 70.9% respectively), both the K/S value and %F were decreased. Furthermore, a white core phenomenon was evident for the fibres of the dyed fabric with a water content of 1.4%. Variation in the L^* values was in line with the K/S values as the fabric water content varied. As expected, steaming time and sodium carbonate dosage can also affect reactive dye fixation greatly and should be determined accordingly for dyeing cotton fabric with low water content.     

Cetylpyridinium chloride cationic finishing improves the dyeing and antibacterial properties of madder dyed cotton

In this work, after cationic pretreatment of cotton fabric with cetylpyridinium chloride (CPC), the compound of citric acid (CA) and succinic acid (SUA) were used as crosslinking agents to dye cotton fabrics with natural madder dye to improve the dyeing and antibacterial properties and realise the multifunctional finishing of cotton fabric. The effects of mordant dyeing, CA + SUA crosslinked dyeing, and CPC/CA + SUA crosslinked dyeing on the microstructure and properties of cotton fabrics were compared. The dyeing by the three processes occurred primarily in the amorphous zone of the fibres, and all kept the original crystalline form of the cotton. CA + SUA crosslinked dyeing and CPC/CA + SUA crosslinked dyeing increased the thermal stability of the cotton fabric. CPC/CA + SUA crosslinked dyed cotton obtained excellent dyeing results with the colour depth value (K/S) of 12.3 and rubbing fastness and washing fastness of levels 4–5, and the levelness and dye permeability were acceptable. Furthermore, the antibacterial rate against Escherichia coli and Staphylococcus aureus reached 99.99%, and the ultraviolet protection factor (UPF) reached 50+. Moreover, the wrinkle recovery angle (WRA) increased by 55% compared with raw cotton. This showed that CPC/CA + SUA crosslinked dyed cotton had excellent antibacterial, anti-ultraviolet, and anti-wrinkle performances.     

Studies involving reactive dyes containing a benzophenone ultraviolet absorber

Nine new fibre reactive dyes containing a built‐in hydroxybenzophenone moiety were synthesised, characterised using electrospray mass spectroscopic analysis, applied to cotton fabrics and the ultraviolet protection factor values of the dyed cotton fabrics determined. The results showed that the anti‐ultraviolet properties of cotton were improved by dyeing with dyes containing a built‐in hydroxybenzophenone moiety, but that the benzophenone ultraviolet absorber need not be covalently linked to dye molecules to provide significant benefit.     

Assessment of uniformity of fibre coloration in Tencel woven fabrics dyed using reactive dyes

Weave structure and fabric density has an influence on dye penetration. The uniformity of dyeing, expressed as the uniformity of fibre coloration, of Tencel woven fabrics comprised of different weave structures, was assessed. The fabrics were dyed by exhaust and continuous dyeing methods using selected reactive dyes. Cross‐sectional images were captured and then given a rating 1–5 with respect to the depth of the fibre filaments of the yarn of the woven fabric. The images were assessed both subjectively and objectively. The uniformity of fibre coloration was expressed in terms of the standard deviation, mean value and histogram analysis such as dispersion and bandwidth. Objective assessment of uniformity of fibre coloration is a more accurate and quicker method than visual assessment and can be used to assess the uniformity of fibre coloration of woven and knitted fabrics dyed by any class of dyes. Improvement of the uniformity of fibre coloration of Tencel fabrics of various weave structures by causticisation of the fabrics and by modification to the padding process was investigated.     

Studies on quinoline type dyes and their characterisation studies on acrylic fabric

Nitrogen heterocyclic fluorescent compounds and their possible dyeing pathway on acrylic fabrics was investigated. Their chemical spectral properties, including fluorescence and ultraviolet–visibility, were evaluated in this work. The colour fastness properties of these dyes attributable to light reflection and washing were examined. The CIE L*, a* and b* values after the dyeing process were studied and the colour fastness properties were also determined. Two quinoline derivatives showed stronger fluorescence properties and were also demonstrated to be non‐cytotoxic towards human HaCaT skin keratinocytes at a reasonable dose. These results led to speculation that these two compounds could be further used as dyes in various textile applications.     

槐米染色棉织物工艺及其抗紫外性能研究

为实现槐米染料的工业化应用及提高棉织物的功能性,分析了使用壳聚糖、Al3+、Fe2+媒染剂预媒染色法对棉织物染色效果的影响,重点研究了铝预媒染方法染色温度、染色时间、pH值等工艺参数对染色棉织物K/S值的影响,并测试了槐米染色棉织物的抗紫外性能。结果表明:直接使用槐米染色的效果较差;壳聚糖媒染对上染效果影响不大,使用铝、铁媒染剂,可得到不同颜色的棉织物;铝媒染剂染色棉织物为鲜艳的黄色,为较好的媒染方法;铝预媒染染色方法染色优化条件为:温度为80℃,染色时间120分钟,染浴pH值为6.8;铝预媒染染色棉织物具有较好的抗紫外性能。     

Determining the dependence of colour values on yarn structure

The colour values of knitted cotton fabrics made from single and plied ring and compact yarns were investigated before and after dyeing. The fabric samples were knitted under the same constructional properties and then dyed with direct and reactive dyes. It was found that fabrics with ring yarns had high lightness and low chroma and colour strength values compared with fabrics with compact yarns. Also colour strength and colour difference values of dyed fabrics were assessed after increasing abrasion cycles (2500, 5000, 7500 and 10 000). The main changes in colour strength values were observed at 2500 abrasion cycles. The effect of abrasion on colour difference values of fabrics having ring yarns was more obvious than fabrics having compact yarns.     

Electrostatic self‐assembly dyeing of cotton fabrics

A new approach to the dyeing of cotton fabrics using an electrostatic self‐assembly method was evaluated. Cotton fabrics were pretreated with 2,3‐epoxypropyltrimethylammonuium chloride and cationic charges were produced on the fabric surfaces. For the dyeing of cotton fabric, reactive and acid dyes were used. Oppositely charged anionic reactive/acid dyes and cationic poly(diallyldimethylammonium chloride) were alternately deposited on the surface of cationised cotton fabrics. Ten multilayer films of dye/poly(diallyldimethylammonium chloride) were deposited on the cotton fabric surfaces using a padder. The build‐up of the multilayer films and the level of colour strength (K/S) achieved are discussed. Samples of cotton fabrics were also dyed with the same dyes, but using the exhaust method, and both types of dyed samples were compared. The washing, rubbing and light fastness properties were evaluated for the dyed fabrics.     

Pretreatment of cotton fabrics with polyamino carboxylic acids for salt‐free dyeing of cotton with reactive dyes

In this study, polyamino carboxylic acids have been used to improve the dyeability of cotton in a salt‐free reactive dyeing process. These polyamino carboxylic acids were prepared by partial carboxylation of polyvinylamine. Cotton fabric was pretreated with polyamino carboxylic acids and dyed with reactive dyes. The colour strengths of the dyed fabrics were evaluated by measuring the K/S values. The fastness properties (washing, rubbing and light fastness) of the dyed cotton fabrics were also measured. The pretreatment of cotton with polyamino carboxylic acids creates positive charges on the fabric surface. In this way, salt‐free reactive dyeing of cotton or dyeing with only a small amount of electrolyte is possible.     

硅氧烷低聚物的合成及其在泡沫染色中的应用

为了通过泡沫染色和光固化改善棉织物的染色性能，合成了一种含有不饱和双键的硅氧烷低聚物，设计了合适的含有聚合型黄色蒽醌染料、硅氧烷低聚物、光引发剂2,4,6-三甲基苯甲酰基-二苯基氧化膦（TPO）、表面活性剂十二烷基硫酸钠（SDS）的泡沫体系对棉织物进行泡沫染色。采用1HNMR和GPC分析了硅氧烷低聚物的化学结构和相对分子质量分布，采用FTIR表征了硅氧烷低聚物和染色棉织物的化学结构，采用SEM观察染色棉织物的表面形态。探讨了硅氧烷低聚物用量、染料用量、SDS质量浓度、TPO用量对泡沫性能和染色性能的影响，分析了硅氧烷低聚物的固色机理。结果表明，染料质量浓度30 g/L、硅氧烷低聚物用量为染料质量的2倍、SDS质量浓度2.0 g/L、TPO用量为染料质量的5%、紫外光照时间5 min时，染色织物染色深度可达5.70，耐皂洗色牢度和干/湿摩擦色牢度均为4～5级，水接触角为110.1°，紫外防护系数>50。硅氧烷低聚物通过侧基上的不饱和双键发生自由基聚合和硅醇基偶合交联实现固色，并赋予织物良好的疏水性能和抗紫外线性能。     

Stabilized nanosilver loaded nylon knitted fabric using BTCA without yellowing

In this study, silver nanoparticles stabilized on the nylon knitted fabric by padding process using 1,2,3,4-butanetetracarboxylic acid (BTCA) and sodium hypophosphite (SHP) without considerable yellowing. This cross-linking combination also dimensionally stabilized the nylon knitted fabric. The SEM images showed the distribution and size of nanosilver within 34 nm. Also, the presence of nanosilver on the fabrics confirmed by EDX and XRD spectrums. The antimicrobial test performed on the treated fabrics against Staphylococcus aureus as a Gram positive and Escherichia coli as a Gram negative bacterium using pour plate test method. A bacterium growth decrease above 96% achieved with 200 ppm nanosilver/BTCA/SHP with standing up to 20 successive rinses. The L*a*b* values had little changes upon increasing the concentration of silver nanoparticles. However the color changes were negligible and the fabric was still white. Moreover, diffuse reflectance spectroscopy, dimensional stability, and water droplet adsorption time as well as statistical analysis of the results investigated and reported.     

Investigation and feed-forward neural network-based estimation of dyeing properties of air plasma treated wool fabric dyed with natural dye obtained from Hibiscus sabdariffa

In the colouring processes of textile products, more environmentally friendly chemicals and finishing methods should be used instead of conventional ones that harm the environment every day, so that alternative realistic ways to protect nature, both academically and industrially, could be possible. Due to some inconveniences caused by synthetic dyes that are widely used today, in this study, ultrasonic dyeing of wool fabric with Hibiscus sabdariffa was carried out after environmental-friendly air vacuum plasma application which increased the absorption of the dyes into the textile material. According to the performance results, colour strengths of the wool fabrics were increased significantly. Surface morphology analysis was carried out and etching effects of air vacuum plasma treatment were clearly seen on the micrographs of the treated wool fabrics. An environmental-friendly green process was achieved through this study and it was concluded that vacuum air plasma treatment could be an alternative green-process as a pretreatment to increase the dye up-take of natural dyeing treatment. Moreover, in this study, a feed-forward neural network (FFNN) model was presented and used for predicting the dyeing properties (L, a, b and K/S) of samples. The experimental results showed that the presented model achieves the regression values greater than 0.9 for all dyeing properties. Consequently, it was considered that the proposed FFNN was successfully modelled and could be efficiently utilised for dyeing characteristics of wool fabrics dyed with natural dye extracted from Hibiscus sabdariffa.     

Color evaluation of wool fabric dyed with Rhizoma coptidis extract

Berberine is the only cationic colorant of natural plant dyes, which lies in the roots of Rhizoma coptidis and stems of phellodendron. In this study, wool fabric was dyed with the extracts of R. coptidis. Color evaluation was characterized with ΔE, L*, a*, b*, c*, H⁰, K/S. Effects of mordant, extraction concentration, pH value of dye bath, and treatment temperature on color values were studied. Results indicated that wool fabrics dyed with mordant, or at higher temperature, or in alkali solution possessed deeper shades and darker colors. And the wool fabric showed good antibacterial property after dyeing with R. coptidis extracts. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3376–3380, 2006     

The role of natural dyes in the UV protection of fabrics made of vegetable fibres

The safest protection from ultraviolet (UV) radiation exposure is offered by textiles including various apparels, accessories such as hats and shade structures such as umbrellas. Their protectiveness depends on fabric composition, (natural, artificial or synthetic fibres), fabric construction (porosity, weight and thickness) and dyeing (natural or synthetic dyes, dye concentration, UV-absorbing properties, etc.). In this study the UV-protection properties were investigated on fabrics made of vegetable fibres (cotton, flax, hemp and ramie), with different construction parameters (drapery and apparel fabrics), dyed with some of the most common natural dyes. The effect of a tannins-based mordant (the galls of Quercus infectoria) on UV-protection capacity was also tested. UV radiation transmittance of fabrics was measured by two methods: one based on the utilisation of a spectrophotometer equipped with an integrating sphere (in vitro test), and the other based on outdoor measurements taken by a spectroradiometer. Transmittance measurements were used to calculate the Ultraviolet Protection Factor (UPF).Our results revealed that thick and dense (cover factor, CF > 94%) drapery fabrics made of vegetable fibres usually showed good UV-protection levels even if undyed. The use of the tannins-based mordant increased, even without dyeing, the UV-protection level up to the very good and/or excellent protection categories when fabric construction was suitable. Dyeing did not further increase the protection level.Lighter fabrics, usually used for apparel, even showed high UV-protection level after just dyeing, provided that CF was above 94%.Taking into account the high concentrations of dyes used in the present work and the utilisation of mordants containing tannins, slight differences in UV-protection capacity were detected among natural dyes tested and between the two different methods of transmittance measurement. However, UV-protection category defined from outdoor measurements was often higher than that calculated by the in vitro test, indicating an underestimation of the actual protection level of tested fabrics assessed by the latter.     

The role of natural dyes in the UV protection of fabrics made of vegetable fibres

The safest protection from ultraviolet (UV) radiation exposure is offered by textiles including various apparels, accessories such as hats and shade structures such as umbrellas. Their protectiveness depends on fabric composition, (natural, artificial or synthetic fibres), fabric construction (porosity, weight and thickness) and dyeing (natural or synthetic dyes, dye concentration, UV-absorbing properties, etc.). In this study the UV-protection properties were investigated on fabrics made of vegetable fibres (cotton, flax, hemp and ramie), with different construction parameters (drapery and apparel fabrics), dyed with some of the most common natural dyes. The effect of a tannins-based mordant (the galls of Quercus infectoria) on UV-protection capacity was also tested. UV radiation transmittance of fabrics was measured by two methods: one based on the utilisation of a spectrophotometer equipped with an integrating sphere (in vitro test), and the other based on outdoor measurements taken by a spectroradiometer. Transmittance measurements were used to calculate the Ultraviolet Protection Factor (UPF).Our results revealed that thick and dense (cover factor, CF > 94%) drapery fabrics made of vegetable fibres usually showed good UV-protection levels even if undyed. The use of the tannins-based mordant increased, even without dyeing, the UV-protection level up to the very good and/or excellent protection categories when fabric construction was suitable. Dyeing did not further increase the protection level.Lighter fabrics, usually used for apparel, even showed high UV-protection level after just dyeing, provided that CF was above 94%.Taking into account the high concentrations of dyes used in the present work and the utilisation of mordants containing tannins, slight differences in UV-protection capacity were detected among natural dyes tested and between the two different methods of transmittance measurement. However, UV-protection category defined from outdoor measurements was often higher than that calculated by the in vitro test, indicating an underestimation of the actual protection level of tested fabrics assessed by the latter.     

Dyeing properties of textiles by Turkish hazelnut (Corylus colurna): leaves,coat, shell and dice

Turkey has a great number of hazelnut trees that possess nutritious components. However, only the inside part of the hazelnut is used as a nutrient, while the rest of it is waste. This study suggests that the waste parts of the Turkish hazelnut could be used as a natural dye for dyeing textile fabrics. The dyeing properties of the leaves, coat, shell and dice of the hazelnut were studied on wool, cotton and viscose fabric by using three different mordants: copper sulphate, iron sulphate and aluminium sulphate. The selected dyed fibre sample surfaces were observed using a scanning electron microscope. The colour strength (K/S), light, washing, rubbing, and perspiration fastness levels of the dyed fabrics were investigated. The experimental natural dyeing results indicate that waste hazelnut‐based products can be used as a natural dye for textile coloration.     

Textile applications of photochromic dyes. Part 4: application of commercial photochromic dyes as disperse dyes to polyester by exhaust dyeing

A series of commercial photochromic dyes was applied to polyester fabric as disperse dyes. The photocoloration properties of the dyed fabrics were investigated by applying techniques previously established in our laboratories using an independent source of ultraviolet irradiation and traditional colour measurement instrumentation. The dyed fabrics showed reversible photochromism, developing pronounced colours from weak background colours on irradiation with ultraviolet light and returning to their original state when the ultraviolet light source was removed. However, the extent of photocoloration and the depth of background colour varied significantly with the particular dye used. The dyeing procedure was optimised by maximising the degree of photocoloration, expressed as the colour difference (ΔE₁) between the colour developed after ultraviolet exposure and background colour, while minimising the background colour, expressed as the colour difference (ΔE₂) between unexposed dyed and undyed fabrics. Optimum dyeing concentrations were determined. The colour development and fading properties, fatigue resistance and storage stability of the dyed fabrics were investigated.     

Application of polycarboxylic acid sodium salt in the dyeing of cotton fabric with reactive dyes

In this study, the effects of polycarboxylic acid sodium salt on the dyeing of cotton with reactive dyes were evaluated by measuring and comparing the K/S values and dyeing fastnesses of the dyed cotton fabric samples. Results showed that the K/S value and dyeing fastness of cotton fabrics dyed with polycarboxylic acid sodium salt, substituting inorganic salts as exhausting agent were close to that of with sodium chloride when dip‐dyeing process was used. While, in pad‐dry dyeing, the K/S value of cotton fabric samples dyed with polyacid salts as exhausting agent was higher than that of with sodium sulfate, and the dyeing fastnesses of these samples were nearly the same. The dyeing mechanism of cotton fabric with reactive dye, using polycarboxylic acid sodium salt as exhausting agent was analyzed. The dyeing exhausting mechanism of reactive dye seems different when the inorganic salt and polycarboxylic acid sodium salt were used as exhausting agent in the dyeing of cotton fabric with reactive dye. The polycarboxylic acid sodium salt, as weak electrolyte, increased the dye‐uptake of reactive dye on cotton fabric not only by screening negative charges on cotton surface, but also by the effect of salting‐out or hydrophobic combination. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

A method for dyeing cotton fabric with anthocyanin dyes extracted from mulberry (Morus rubra) fruits

For the first time, the natural anthocyanin dyes (mainly consisting of cyanidine 3‐glycoside) extracted from mulberry (Morus rubra) fruits has been successfully used to dye cotton fabric, with a dyeing property performance good enough for potential commercial applications. In this study, succinic acid was firstly incorporated into cotton fabrics by esterification to the hydroxyl groups of cellulose, forming an anionic site for the dyes. The performance of the modified material was characterised by Fourier transform infrared spectroscopy and tensile strength. Results showed that the tensile strength of cotton fabrics was mostly retained after modification. The anthocyanin extracts from mulberry fruits were used to study the dyeability of the control and modified cotton fabrics. Red and deep purple (aubergine) are two main shades of cotton fabrics dyed with mulberry fruit extracts. Most importantly, aubergine shade is rare in cotton fabrics dyed with natural dyes. Modification with succinic acid clearly increased the colour strength of the dyed cotton fabric. The colour strength of dyed cotton fabric was improved from 2.7 to 5.3 in the case of dyeing without mordants, and from 3.2 to 6.9 in the case of dyeing with tin mordanting. Meanwhile, the colour fastness was improved by 0.5–2 grades with increasing succinic acid concentration in the finish solution. The colour fastness to perspiration, crocking, light, and washing of fabric dyed with simultaneous tin mordanting and modified with 30 g l^?1 of succinic acid was found to be acceptable, with a grey scale grade of at least 3. As for home laundering, neutral soapy solution was more acceptable than alkaline soapy solution.     

The colour and fastness of natural saffron

Cotton and wool fabrics have been dyed with the aqueous extract of saffron containing α-crocin as the main colorant species. The dyeings were carried out with and without metal salts as mordants. The wash and light fastness of the dyed fabrics was studied. The colour of the fabrics was investigated in terms of CIE L* C* H* values.