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

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.

The color sensitivity of the dyeing recipe is one of the most important parameters for controlling the dyeing process. This work studied the effect of color depth on the color sensitivity of a recipe of wool dyeing with weld natural dye. For this purpose, the woollen yarn was dyed with weld at low and high color depth using pre-mordanting method. The color sensitivity of the dyeing recipe was evaluated by measuring the color depth (K/S), color difference, and color sensitivity coefficient. The color sensitivity coefficient was measured by 10 % change in parameters of the dyeing recipe, such as dye concentration, mordant concentration, temperature, time, pH, and L.R. Also, the simultaneous color sensitivity of two, three, four, five, and six parameter combinations were measured by experimental and computational methods. The measured color sensitivity by the computational method was higher than the experimental method. In general, the color sensitivity at low color depth is more than high color depth.

Felt is one of the most unique textiles created without weaving and through braiding. Iran is a pioneer of felt production in the world. Given the intense economic competition in the world, it is important to update and improve this product according to advancements and requirements of the society. One of the defects in the currently used felts is the difficult way of washing self-cleaning to the distortion of its design, pattern and form following washing. Since removing this defect can enhance the productivity of felt, the present article was designed to solve this problem through the use of nanoparticles with a specific concentration. Toward this goal, nanoparticles of titanium dioxide, cerium dioxide and magnesium oxide were selected to create self-cleaning properties and resistance against abrasion in traditional woolen felts. Accordingly, necessary tests were performed on 10 pieces of felt with 4 repetitions. The obtained results showed that felts containing 0.3% titanium dioxide had a 119% increase in self-cleaning and a 53% increase in wear resistance when compared to samples without nanoparticles. This increase was also significant when compared to other nanoparticles at a 5% level.

Nowadays dyeing of textiles with natural dyes has been considered according to environmental effects based on lower using of the synthetic dyes and chemical auxiliaries. In present research, the dyeing parameters including; type of mordant, concentration of mordant and concentration of clove have been investigated. The color strength (K/S) value and the color coordinates (L*, a*, b*, C*) of samples were obtained using calorimeter in CIELab color space. The results showed the dyed samples in presence of Cu and Al as mordant have higher lightness (L*) compare with dyed samples dyed with Fe. The ultraviolet protection results showed higher blocking effect of sample in presence of clove against photodegradation of methylene blue (MB) under sunlight irradiation. The antibacterial assessment of the dyed samples showed reduction of bacteria rate against S. aureus (95%). Also washing fastness assessment of the dyed samples showed the great durability of clove on wool in presence of mordant.

With the growing awareness about cleaner surroundings, using natural materials in textile dyeing has been developed recently. In this way, in this research, one of the galls of the oak tree named Sichka was selected as a sample of cultural waste, and the optimal conditions of wool dyeing were investigated for the first time. The results show that sichka is a vast source of polyphenolic and tannins compounds and then can be considered an excellent candidate for wool dyeing and produced outstanding antibacterial properties. Results indicate that for the conditions used in our experiments, the optimum dyeing conditions are dye concentration of 45 % at the temperature of 80 ºC, time of 60 min, and pH of 4.5. The results also show that the wheat barn and citric acid were used as the bio- mordants to increase the affinity of wool yarns to the dye extract and improve dye fastness properties. It provides an excellent way to protect the ecosystem as much as possible and a space for new businesses with value-added.

Ailanthus altissima is a fast growing, deciduous, and exotic invasive tree that is able to germinate and grow in a wide variety of soil and site conditions. In this study, the dyeing ability of woolen yarn with the fruit of Ailanthus altissima tree as a natural dye was evaluated. The effect of different dyeing conditions such as mordant concentrations (0 to 6% Wt.%), dyeing time at boiling temperature (30 to 90 minutes), pH of the dye bath (3 to 8) and the dye concentrations (60 to 200% Wt.%) on color strength of dyed sample were studied. The color characteristics of the dyed yarns and the optimal condition of the dyeing conditions were evaluated based on the maximum color strength. The antibacterial property of Ailanthus altissima tree fruit extract was investigated against gram-negative (Escherichia coli) and gram-positive (Staphylococcus aureus) bacteria. Independent research variables such as dyeing time, pH of dye bath and dye concentration had a significant effect on color strength and using of alum as a mordant in applied amounts (0 to 6% Wt. %) had a little effect on the color strength of dyed samples. The dyed woolen yarn with Ailanthus altissima tree fruit has good washing and light fastness and presented good antimicrobial properties against gram-negative and gram-positive bacteria in applied concentrations of 12.5% up to 100%.

Nowadays, Due to the environmental pollution associated with synthetic dyes, the attention to the application of natural dyes in the textile industry is growing. Natural dyes are environmentally friendly and possess some advantages and disadvantages in comparison with synthetic dyes. One of the main drawbacks of natural dyes is the low exhaustion of textile fibers. To improve the dyeing of textiles with natural colorants, several methods, including metal mordanting, bio-mordanting, treatment with nano-clay, ultrasound, microwave, plasma, ultraviolet, and enzyme, besides the attachment of chitosan, cyclodextrins, and dendrimers to the fibers have been employed. Due to the toxicity of the majority of metallic mordants, the use of bio-mordants and surface modification of fibers by physical and chemical methods are considered as alternative strategies for promoting the natural dyeing of wool fibers. These methods usually improve the sorption of natural dyes by wool fibers and improve the fastness properties of the dyed fibers in most cases. In this paper, the different methods employed to enhance the dyeing of wool fibers with natural dyes are discussed and summarized.

Due to the environmetal and health related problems associated with the use of synthetic dyes, there is a growing tendency for the use of eco-friendly and less harmful natural dyes in the textile industry. In this study, the leaves of Citrus aurantium were used as a new source for environmentally-friendly dyeing of wool. The effect of four important variables including dye concentration, mordant concentration, pH, and dyebath temperature on the color strength of the dyed samples was investigated. Box-Behnken design and response surface methodology was employed for the design of the experiments and analysis of the obtained data. the results showed that the highest color strength was obtained when dyeing using 150 %owf of the natural dye powder and 5.5 %owf of aluminum sulfate, at pH=8 and 76 °C. The sample dyed at the optimal conditions was tested for fastness properties and showed acceptable fastness against washing, light, and rubbing.

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.

Nowadays, there is an increasing interest in finding new sources of natural dyes with easy accessibility, high color strength, low cost, and high fastness properties. In this study, harmal seed has been used as a new source of natural dye on wool fibers. Harmal (Peganum Harmala) can be found extensively in several regions of Iran as a self-growing wild plant. Dyeing pH, dyeing Temperature and alum mordant concentration were chosen as the main influencing factors of this study and 25 samples were prepared according to the experimental design. The amounts of color strength of the dyed samples were measured. The results showed that the color strength was increased with increasing the dyebath pH and dyeing temperature. Increasing the concentration of alum decreased the color strength.

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.

Low temperature plasma technology has attracted the attention of several researchers as it is a fast and environmentally friendly method for surface modifcation of textiles. In this study, the effects of plasma treatment on physical and chemical properties of wool fbers including surface morphology, tenacity, surface functional groups and water wicking are reviewed. Due to the etching effect, cold plasma treatment can improve the hydrophilicity and dyeability of wool fbers. The effects of cold plasma treatment on dyeing of wool fbers with different synthetic and natural dyes have been also reviewed. Generally, the surface modifcation of wool fbers using oxygen, nitrogen and argon plasmas can improve the dyeability of wool fbers with anionic dyes. Furthermore, the color fastness properties of the plasma treated wool samples are improved compared with those of the untreated samples.

In this study, the extract of Rhuem Ribes L. flowers was used for dyeing of wool fibers. Oxygen plasma was used as a pretreatment to enhance the dyeability of wool fibers and metal mordant was eliminated from the dyeing process. The surface morphology of the wool fibers before and after plasma treatment was investigated by SEM images. FTIR analysis was employed to study the chemical changes imparted to the wool fibers by plasma treatment. The surface of wool fibers was etched and oxygen containing groups were introduced to the surface of wool fibers. The fastness of the dyed samples to washing and light was measured. The plasma treated samples showed better dyeability as well as good fastness to washing and light.