天然染料苏木精用于真丝绸染深色媒染工艺的分析与优化

通过对苏木精染真丝绸时常规媒染工艺的分析,制定了适合苏木精染深色的复合媒染工艺,并进一步优化,设计出更符合环保要求的媒染方法三价铬预媒废水回用法.     

Study of the dyeing properties of saffron and ultrafiltrated saffron powders,as colourants for natural and synthetic fibres

There is a noticeable growing interest in the use of natural dyes in contemporary textile dyeing, motivated by the requirements imposed, in favour of environmental prosperity. The use of natural dyes reduces significantly both the energy requirements and the environmental impact of the process. In the present work natural and synthetic fibres were dyed with the dyestuff isolated from Crocus sativus L., after aqueous extraction of the dried stigmas of the plant. Additionally, part of the powder was purified by using ultrafiltration technology. The saffron extract and the ultrafiltrated saffron retentate were used to dye cotton, wool, nylon and polyester, in various depths of shade and temperatures. Both saffron and ultrafiltrated saffron successfully dyed not only the natural substrates, but also the synthetic ones, while higher dyeing temperatures produced level dyeing with all substrates used. Ultrafiltrated saffron powder produced brighter and much stronger dyeing to the original saffron powder, due to the elimination of extraction by-products. Isothermal adsorptions for both colourants were performed on all substrates in order to investigate their adsorption mechanism. It was found that saffron and ultrafiltrated saffron follow a Freundlich-type adsorption isotherm on cotton, wool and nylon which is a typical mechanism for a planar-directed dye of big molecular weight. Nernst-type adsorption was found to occur on polyester which again is typical for the adsorption of disperse dyes on polyester. Thus, saffron can be claimed as a universal dye, able to successfully dye natural and synthetic substrates.     

Metal ion effect on dyeing of wool fabric with catechu

Wool fabric was dyed with catechu by two different process sequences using various metal sulphates as mordant. The dyeing behaviour has been assessed by measuring K/S values and different fastness properties. The effect of different metal ions have been studied with respect to their influence on colour and fastness properties. The mechanism of mordant interaction with the fibre has been briefly considered.     

Ecofriendly ultrasonic natural dyeing of cotton fabric with enzyme pretreatments

Ecofriendly ultrasonic textile dyeing with natural dyes such as Acacia catechu and Tectona grandis show better and faster dye uptake after enzyme pretreatment on cotton fabric, and results of dyeing are better than metal mordanted fabric. It is observed that there is marked improvement in wash-fastness and light-fastness. The role of enzyme pretreatment is primarily for better absorbency, adherence and dyeability of these dyes on cotton fabric, thereby completely replacing metal mordants with enzyme for adherence of natural dyes on cotton. Scanning electron microscopy show surface characteristics at different stages of dyeing. The effect of sonication on the dyeing is compared with conventional heating. The study also shows enhancement in CIELab values.     

天然苏木色素染发性能研究

以天然苏木色素为主要原料配制染发剂,考察染色温度、时间、pH值及媒染剂浓度等对白色牦牛毛染色效果的影响。结果表明,天然苏木色素对白色牦牛毛具有直接染色效果,其中温度是最重要的影响因素。铝离子与锌离子可使毛发颜色偏向棕色,铁离子可使毛发颜色偏向黑色,其中温度与媒染剂浓度是影响颜色的重要因素。本实验为不同颜色染发剂的配制提供了理论依据。     

天然植物在染发剂中的应用研究进展

综述了植物染发剂的现状、进展和发展趋势及相应的评估、论证和建议。为开发绿色健康、安全无毒的天然植物染发剂提供参考。     

Application of rare earth as mordant for the dyeing of ramie fabrics with natural dyes

Selecting appropriate metallic compounds as mordants is essential for dyeing with natural dyes. This paper presents the application of rare earth compounds as mordant for the dyeing of ramie fabrics with four kinds of natural dyes. The influences of pre-mordanting, simultaneous mordanting, and post-mordanting on the dyeing effect were explored. The post-mordanting was proved to give rise to the highest dye uptake. The effects of dyeing conditions including dyeing temperature and time, dyeing bath pH and the concentration of rare earth on the dye uptake were investigated systematically. The fabrics dyed with natural dyes in presence of rare earth as mordant exhibited high color shade stability in the baths with pH varying from being acidic to neutral and alkaline. Employing rare earth as mordant apparently raised the color fastness to washing, rubbing and light of the ramie fabrics dyed with the natural extracts. In comparison with the commonly used metallic salts, using rare earth chlorides as mordants can greatly reduce the ionic concentration employed in natural dyeing. This study proved that rare earth would be a kind or promising environmentally friendly mordant in natural dyeing.     

Colour and fastness of natural dyes: revival of traditional dyeing techniques

Cotton and wool fabrics were dyed with nine natural dyes obtained by aqueous extraction of the original plants/insect in an attempt to reconstruct traditional textile dyeing recipes, to optimise the methodology at all stages, i.e. extraction, mordanting and dyeing, and to standardise it. Cochineal, madder, alkanna, henna, brazilwood, red sandalwood, safflower, indigo and logwood were used for the dyeings, which were carried out directly and after mordanting of the textile material. A variety of mordants, namely, aluminium potassium sulphate, potassium dichromate, copper sulphate, zinc chloride, iron(iii ) chloride, iron(ii ) sulphate and tin chloride, is anticipated to meet both early and recent requirements and options. The dyeings were evaluated through colour measurements and standard wash, light and rub fastness tests. Generally, the mordanting process known for many centuries and connected with the textile dyeing resulted in an improvement in dye absorption and fastness properties mainly for the cotton samples, as is concluded from the tests and measurement assessments.     

Extraction of polyphenolic substances from bark as natural colorants for wool dyeing

In Europe, considerable amounts of bark are available from wood‐processing industries such as forestry and timber production. Polyphenolic components can be collected by hot water extraction. The extracted compounds can then be applied as colorants in textile dyeing operations. In this study, a comparative assessment of four different tree species with regard to their colouristic potential for wool dyeing was performed. Aqueous extracts from alder, ash tree, spruce and oak bark were prepared and analysed for their total phenolic content and ultraviolet (UV) absorption at 360–370 nm. The extracts were used for meta‐mordant dyeing by adding iron sulphate mordant (FeSO₄ × 7H₂O). For comparison, iron salt‐based dye lakes were prepared and used in dyeing experiments. For each tree species, a specific correlation between the total phenolic content of the dyebath and the colour depth in terms of K/S and CIELab coordinates was observed, both for the aqueous extracts and the dye lakes. Based on this relationship, standardisation and quality control of raw materials and dye lakes can be installed as important stages in the industrialisation of natural colorants from bark. The preparation of concentrated dye lakes permits formation of a concentrated colorant as dye product, which then can be standardised and delivered to textile dyehouses, similar to synthetic dyes. The preparation of dye lakes offers a relevant route towards achieving the commercialisation of bark extracts as natural colorants.     

Supercritical fluid dyeing of synthetic and natural textiles – a review

Supercritical fluid dyeing is an interesting alternative to the conventional aqueous process because of its environmental benefits. The aim of the paper is to provide the reader with an up‐to‐date overview of this subject, covering various aspects, such as the solubility and equilibrium partitioning of the dyes, mass transfer phenomena and solvent–polymer interactions occurring during coloration, up to the most recent reports on the technology of the dyeing process. Even though the best results have been obtained in the coloration of synthetic textiles, particular attention is given to the dyeing of natural textiles, which is, at the moment, the limiting step of this technology.     

Oxygen plasma pretreatment improves dyeing and antimicrobial properties of wool fabric dyed with natural extract from pomegranate peel

This paper presents the application of conventional potassium aluminium sulphate wool mordanting and a biochemical method with silver nitrate (as antimicrobial agent and mordant)_, alone and in combination with oxygen plasma, as part of comprehensive research into pretreatment processes for wool dyeing with natural extract from pomegranate peel (Punica granatum L.). Pretreatment with oxygen plasma significantly improved the hydrophilicity and tensile strength of all tested samples and showed that oxygen plasma can improve K/S, washing fastness, and even replace certain mordants in wool dyeing with natural pomegranate dye. All dyed samples exhibited good antibacterial activity against Staphylococcus aureus, which can be contributed to the phenol content in pomegranate dye. Only after 28 days of intensive ageing in natural weathering conditions did K/S and antibacterial activity against Klebsiella pneumoniae slightly decrease in dyed samples pretreated with oxygen plasma.     

Clay nanoadsorbent as an environmentally friendly substitute for mordants in the natural dyeing of carpet piles

The aim of this work was to assess the possibility of using a bentonite‐type clay as a promising substitute for mordants in the natural dyeing of wool with madder. Wool yarn was treated with nanoclay by using three conventional methods of pretreatment (before dyeing), simultaneous dyeing with madder in the presence of clay, and aftertreatment (after dyeing). Madder was used as a natural source of colorant. The scientific methods employed in this study included Fourier Transform‐infrared spectroscopy, ultraviolet‐visible spectrophotometry, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, moisture regain measurement, tensile strength tests, reflectance spectrophotometry, and fastness evaluation. The intensity of the major peaks in the Fourier Transform‐infrared spectra of the nanoclay‐treated wool yarn indicated chemical changes in the polypeptide functional groups in the wool structure. Madder exhibited higher dyeing properties on clay‐pretreated samples compared with untreated wool. The results of colour measurements showed that the colour strength of the dyed samples improved with an increasing amount of clay in the pretreatment baths.     

Pomegranate fallen leaves as a source of natural dye for mordant-free dyeing of wool

The application of metal mordants is usually necessary in dyeing of wool with natural dyes to improve the dye exhaustion and fastness properties. The majority of metal salts generally used as mordants are considered as toxic and it is important to find replacements for them. Plant sources with high content of tannins are good candidates as bio-mordant or colourant to overcome this drawback. In this study, the waste fallen leaves of pomegranate tree were used as a source of natural dye for the eco-friendly dyeing of wool fabric without the use of metal mordants. The dyeing process variables including dye concentration, dyebath pH, and temperature were optimised using response surface methodology to obtain the highest colour strength. The colour strength was increased by increasing the natural dye powder up to 100%owf while the optimum pH and dyebath temperature were 4 and 100°C, respectively. The sample dyed under the optimal condition exhibited good fastness properties against washing and light. This study approved the potential of Punica granatum fallen leaves for the dyeing of wool without any mordant, while high fastness properties were obtained.     

Metal complexes of natural and synthetic fabrics grafted with vinyl monomers by gamma irradiation

Graft copolymers of natural and synthetic fabrics with acrylic acid (AAc) prepared by gamma irradiation were transformed into metal complexes of the divalent metal ions of cobalt, nickel, and copper. The factors that affect the grafting process without affecting the physical properties of fabrics and homogeneous grafting were studied. These factors involved inhibitor (FeCl₂) concentration, solvent composition, AAc concentration, and irradiation dose. The results showed that the appropriate irradiation dose in all cases was 20 kGy, whereas the inhibitor concentration was 0.1 wt% in the case of cotton and 0.2 wt% in the case of cotton/polyester blend and polyester fabrics. The suitable solvent composition was H₂O (90%)/MeOH(10%) in the case of cotton and H₂O (90%)/MeOH(10%) in the cotton/polyester blend and polyester fabrics. On the other hand, the suitable AAc concentration was 30% in the case of cotton and 50% in the cotton/polyester blend and polyester fabrics. The homogenous grafting and subsequent distribution of metal complexation was illustrated by a method based on the measurement of color parameters. Moreover, the effect of radiation grafting and metal complexation on the water absorption and mechanical properties of fabrics was investigated. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers     

Influence of plasma sputtering treatment on natural dyeing and antibacterial activity of wool fabrics

In this paper, the effect of plasma sputtering treatment on the natural dyeing properties of wool and the possibility of substituting it for mordant treatment have been studied. We used madder and weld as natural dyes and copper sulfate (CuSO₄) as a metal mordant. We also used, copper as the electrode material, in a DC magnetron plasma sputtering device.     

Ultrasound-assisted enzymatic scouring of jute optimised by response surface methodology and its natural dyeing

India is the largest producer of jute in the world and the use of this natural fibre in various value-added applications is gaining momentum. The use of white biotechnology involving enzymes for the efficient processing of jute is considered to boost its productivity. The present investigation deals with the pretreatment of jute by using ultrasound-assisted enzymatic scouring followed by bleaching and dyeing. The process showed optimum removal of impurities and improved water absorption capacity with minimal damage to fibre tensile strength. The process parameters and conditions were determined by response surface methodology, where weight loss of jute was kept as the main response. The optimised recipe obtained was 2.8% enzyme concentration, 1 g/L wetting agent at 55°C for 10 minutes at an ultrasound frequency of 40 kHz. The optimised recipe was compared with conventional high-temperature long-duration enzymatic scouring and was found to have an equal performance. Further, the scoured jute was dyed with a natural dye extracted from sappan wood and madder. Fourier Transform–infrared analysis was used for characterisation. The wash and light fastness of dyed jute yarn were evaluated and found to meet the industry norms.     

Dye distribution in supercritical dyeing with carbon dioxide

The measurement of equilibrium dye uptake in PET fiber is carried out using a flow-type cylindrical vessel. Using the expanded liquid model in which both phases are supposed to be liquid mixtures, the equilibrium uptake of C.I. disperse red 60 may be calculated from each binary interaction parameter of carbon dioxide–dye, carbon dioxide–PET and dye–PET binary systems. The calculated uptake is compared with the observed one with the same order of magnitude, even though the former is overestimated. The binary interaction parameter of dye–PET system that is obtained from the equilibrium dye uptake in PET is smaller by about 1.5 than that obtained by the binary system. Nevertheless, it is found that the predicted uptake of dye with using the interaction parameter regressed from the ternary data is in excellent agreement with the experimental one. The distribution of C. I. disperse red 60 into supercritical fluid and PET phase at equilibrium can be predicted and compared with the experimental one. The estimated distribution coefficient increases with the pressure increase, because the sorption of dye in PET fiber increases slowly with the pressure than the dye solubility in carbon dioxide does. This tendency is weakened with increase of temperature.     

天然水体成分对海绵铁处理印染废水的影响研究

研究了水体中天然有机质(NOM)及常见阴阳离子对磁性海绵铁超声降解染料酸性蓝9(AB9)的影响。结果表明:p H为5.0和9.0、NOM质量浓度低于40 mg/L时,随着NOM浓度增大,对AB9降解的抑制作用逐渐增强;用Na Cl模拟水溶液背景离子强度(IS)发现,IS对降解的影响可忽略不计;阴离子SO42-、NO3-、CO32-和PO43-对降解抑制强度排序为:PO43-CO32-SO42-NO3-,阳离子Ca2+、Mg2+、K+和Zn2+对降解效率有不同影响;NOM和硬度离子共存时,在一定浓度范围内降解率略有提高。