جستجوی مقالات مرتبط با کلیدواژه « dyeing » در نشریات گروه « مهندسی شیمی، نفت و پلیمر »

Tannins are natural biocompatible compounds and are abundantly available in plant sources. Tannins have a polyphenolic structure similar to chemical phenols. Various methods have been reported for the extraction of tannins, and the solid-liquid method with the use of water as a solvent is very common. Tannins also have antioxidant properties, and their health and medical applications are related to this property. The common uses of tannins are leather tanning, livestock and fishery feed, beverage production and wood glue preparation. Nowadays, due to the structure of polyphenol tannins and attention to environmental issues, studies are being conducted to develop its applications. Some of the emerging applications of tannins are corrosion inhibitors, improving the properties of dyed fibers, wood protective coatings, preparation of polyurethane resins, etc. This article introduces tannin, extraction methods, and the most important uses of tannins, as well as the latest published research. In the end, cost and commercialization limitations are examined.

Introducing new uses for agricultural waste is important to prevent environmental pollution and reduce waste disposal costs. The oleaster, often called the Russian olive, has culinary and medicinal applications, but its byproducts (seeds and peel) are frequently thrown away. Oleaster and its components are tannin-rich and can be used as mordants in dyeing. The extraction process was carried out in the presence of ethanol and was evaluated by analytical methods (FTIR and DSC). The percentage of phenolic compounds in peel and seed of oleaster fruit was obtained by the TPC method at 81.2 and 45.5 mg/ml, respectively, which indicates the possibility of using these extracts as mordants. Dyeing was done using Reseda extract on wool yarns. Alum was utilized as a low-risk mineral mordant with a concentration of 5% to evaluate natural mordants' effectiveness. The dyeing method with a 40% concentration of Oleaster peel and reseda extract yields the greatest K/S (19.47). Finally, the dyed samples were evaluated regarding color and fastness properties.

Handmade carpets, whose design, pattern, colors, and textile structure express Iranian artistic identity and culture, are also considered a strategic economic product for job creation and currency exchange. The purpose of this research is to study and understand the strengths and opportunities in the use of dyes and appropriate and green dyeing methods in the preparation of raw materials, color scheme, and composition and to identify and analyze the weaknesses and threats due to the poor quality of the visual appearance in the Iranian handmade carpet trade and providing creative strategies to increase its competitiveness, sales, and export. The analytical process of SWOT matrix analysis was used to maximize strengths and opportunities and minimize weaknesses and threats. The data collection tool was a questionnaire completed using the Delphi method in a statistical community of 46 related experts, and their data were analyzed. The results indicate the necessity of following the conservative strategy of preserving and maintaining the strengths and taking advantage of the opportunities for the development of the business of this product in today's market conditions. Among the creative strategies for developing this product is branding and using the knowledge of modern marketing and e-commerce with the key points of the green product and, of course, the guarantee of its appearance quality and longevity.

The extraction process is very important in separating and purifying dye components from the natural plants. Various extraction methods have been used to obtain valuable natural compounds. Compared to the traditional extraction method, each has advantages, including less solvent consumption, shorter time, and less environmental pollution. This research studied the effect of non-ionic surfactants at various initial concentrations in extracting natural colorants from madder, weld, and walnut.</em> </em>The results showed that using surfactants improved the amount of extracted colored compounds in the extraction process. The efficiency of the extraction process in the presence of each surfactant is diverse due to the different color compounds in each colorant used. The extraction process of weld natural dye has been improved by 60 % in the presence of Keol surfactant. Also, the color strength of dyed wool yarns in the presence of surfactants has increased by 30-44 % compared to the control dyed sample (without surfactants). The results of this research clearly show that it is possible to use non-ionic surfactants to improve the extraction efficiency, color strength, and better leveling of the natural dyes on the wool yarn.  

The deposits of dispersed dyes on dyed polyester fibres are an important problem in polyester fibre dyeing that should be tackled properly. These dyes deteriorate the wash, rubbing, and sublimation fastness and the brightness of the dyed fibres, especially deep-dyed ones. Therefore, clearing these surface dyes is necessary. Conventionally, a reduction clearing process is used to remove the surface dyes, in which sodium dithionite, a reductant, and sodium hydroxide, an alkaline, are used. This process has a significant part in removing surface oligomers and auxiliaries, such as carriers. Unfortunately, this process is not environment friendly, and the derivatives of its chemicals are toxic to human health, and there are technological and economic issues associated with this process. In recent years, numerous research for removing surface dispersed dyes by alternative, less-pollutant, and more efficient processes have been proposed. These alternative processes include surfactants, enzymes, and other reductants, oxidative clearing, plasma, electrochemical methods, and the application of easily clearable synthesized dyes. Each of these proposed processes has its own pros and cons, and they have special needs. In the present review paper, various processes of clearing surface dispersed dyes from the dyed polyester fibres are investigated and compared with the traditional reduction-clearing process.</em>

In this research, the dyeing of nylon fabrics with sumac as a natural dye was investigated and the effect of keratin treatment on the dyeing properties was studied. For this purpose, first keratin was extracted from chicken feathers by the reduction hydrolysis method, and then surface modification of nylon fabric with the extracted keratin was performed via the exhaustion method. The chemical structure of the treated fabrics was evaluated by FTIR and the results proved the successful keratin treatment on the surface of the fabrics. The obtained results showed high dye absorption of keratin-treated fabric in comparison with mordant-treated and untreated fabrics. Thus, keratin could be used for enhancing the absorption of natural dyes. Colorfastness properties of the dyed fabrics with sumac were evaluated and high washing and rubbing fastness were attained. Finally, the antibacterial properties of the dyed fabrics against both gram-positive and gram-negative bacteria were performed and the results showed the antibacterial activity of sumac.

Today, floor coverings play an essential role in human life and have a variety of uses. Among the most common home floor covering are carpets (handmade and machine-made) and moquette, which are used in various places, including office and home environments. On the other hand, increasing global competition in textiles has posed many challenges for researchers and the textile industry. The rapid growth in the production of textiles with multifunctional has created new opportunities for the application of new additions. New finishings with high value-added supplements for textiles are also in increasing demand by the global consumer market. Therefore, new technologies such as nanotechnology and plasma technology will be discussed in the current research to create capabilities such as antibacterial, anti-insect, anti-fire, etc., properties on floor coverings, especially carpets.

Using natural dyes is one of the main features and advantages of eco-friendly Iranian hand-woven carpet, which has numerous adherents. This work studies the past, present, and future application of natural dyes for dyeing piles of the hand-woven carpet. Several investigations have been done on preparation, mordanting, and dyeing with natural dyes, as well as the use of a dyeing machine for dyeing the pile of hand-woven carpets. At the end of this research, little information is provided about the future of the use of natural dyes for dyeing piles of the hand-woven carpet. Studies show that if the extracted natural dyes produced  at high volume and reasonable prices, in the future, the hand-woven carpet piles can be dyed by fiber dyeing machine, yarn dyeing machine, hank dyeing machine, and bobbin yarn dyeing machine.

At present, a higher demand is put towards the use of natural dyes due to increased awareness of the environmental and health hazards associated with the synthesis and use of synthetic dyes. Natural dyes are non-carcinogenic, produce soothing and exclusive color to the textiles, and have better biodegradability and higher compatibility with the environment. However, with the increased interest in natural plant dyes a greater importance was given to using mordant in dyeing processes. The mordants classified into two main groups: natural and metal mordant. The action of the mordant is purely chemical bonding, which is fixed on the fibers in combination with any given colorants. This paper presents the latest research on metal mordant and the development of natural mordant for use in the fiber dyeing process. For this end, an attempt structure properties to improve dyeing properties and to test landscape perspective.

Laccase is a biocompatible compound which is able to catalyze the oxidation of polyphenolic aromatic dyes and graft them to wool. Weld (Reseda Luteolla, L.) as a natural dye, contains polyphenolic aromatics with flavonoid structure and could be a substrate for Laccase. In this research, the effect of laccase on Weld and its use to make a covalant bond between wool and polyphenols compounds of Weld was studied. For this purpose the colourant compounds of Weld were extracted and the effect of laccase on it was studied by UV-Vis spectrophotometry, Size-exclusion chromatography and measuring the changes in the dissolved concentration of the oxygen co-reactant. Kinetic of Laccase-Catalyzed Oxidation of weld was studied and the effect of laccase on weld-dyed wool was surveyed. The results showed that Weld is a suitable substrate for laccase and the use of laccase can improve the dye fixation, and dye fastness against washing.

Organic acids, commonly known as “polycarboxylic acids”, having different numbers of functional groups, as green, sustainable, bio-compatible, environment-friendly, inexpensive, efficient, and safe chemicals have found extensive applications in different industries, more especially in textile industry. Polycarboxylic acids have been used in various parts of textile industry in applications such as cross-linking and enhancement of dimensional stability of polymeric materials and fibers, binding/cross-linking enhancer for chemicals, polymers and nano-materials, antimicrobial finishing, multifunctional auxiliaries in dyeing and finishing processes of textiles, bio-mordant, antioxidant for improvement of light fastness and life time of textiles, etc. The aim of this review paper is to examine the latest advancements on the use of organic acids in development of textile materials. Hence, at first, properties and characteristics of organic acids, extensively used in textile industry, are described. Then, the latest developments using organic acids in various parts of textile industry are reviewed and the results are compared with those of conventional methods in terms of superiority and inferiority of each method.

The aim of present study was to investigate dyeing and fastness properties of chitosan-cyanuric chloride hybrid (Ch-Cy) modified woolen yarn with madder natural dye which is used in hand-knotted carpet pile. Modified yarns were dyed with madder root natural dye and the impacts of some important factors such as Ch-Cy concentration, madder dye concentration, pH, temperature, and time of dyeing were investigated. Optimum dyeing results were obtained using 2%owf of Ch-Cy, 100%owf of madder dye, dyeing pH=7, temperature of 100 ˚C, and time of 60 min. Results revealed that Ch-Cy was effective in the improvement of dyeing properties of woolen yarns, so that the dye exhaustion and color strength values increased by 7% and 2 ratings, respectively. Fastness data against wash, light, and rub as well as colorimetric data indicated that wool modification did not impair color fastness of dyed substrates. Further, hue remained nearly unchanged compared to dyed pristine wool. Therefore, based on the results obtained, it was concluded that modification of woolen yarns with Ch-Cy resulted in better dyeing performance, deeper shades, and saving crude dye material in madder dyeing of wool.

Supercritical fluids have found numerous promising applications due to its excellent properties. A number of research groups have also investigated the application of scCO2 to textile dyeing. Dyeing in supercritical fluids has been identified as a new and acceptable method that has been replaced with conventional dyeing methods of not discharging waste aqueous effluent containing colored compounds and concentrated electrolytes. Today, there is a need to reduce the amount of wastewater containing dye, chemical agents, and the like in the conventional method for the dyeing of textiles from the viewpoints of the cost of wastewater treatment and environmental pollution. In this way, a new dyeing method using supercritical CO2 fluid, supercritical fluid dyeing, has been developed. Dyeing in supercritical CO2 is carried out analogous to aqueous systems. Both decisive tasks of water at dyeing, which means the transport of dyestuff and heat to the fibre, are in the new dyeing process replaced with supercritical fluids. The new dyeing method is particularly attractive as it is non-toxic, non-flammable, and cheap. In addition CO2 has mild critical conditions and can easily be recovered and recycled after use. The aim of this paper is to provide the reader with an up-to-date overview of this subject. Wool and silk fibers have found several applications in textile industry especially in hand-knotted carpets. In this paper, various methods for the dyeing of these fibers in supercritical CO2 has been investigated, which is, at the moment, the limiting step of this technology.