Electrochemical Dyeing of Cotton Fiber for Environmental Protection

For environment-friendly dyeing, electrochemical dyeing method was researched. The low consumption of additives during dyeing is beneficial to environmental protection,and the electric field of electrochemical dyeing reduces the salt. Moreover, the K/S value of the fabric increases significantly at the same dye concentration. The alkaline electrolyte in the electrolytic cell may enhance the self-corrosion of the electrode during the electrochemical dyeing process. The results show that the electrochemical dyeing can reduce the amount of additives during the dyeing process.

The dyeability and after-dyeing wearability of TPU-based 3D-printed fabrics

PurposeThe purpose of the paper is to study the dyeing process of three-dimensional-printed (3DP) fabrics, and then study the wearability of the fabrics before and after dyeing to provide a feasible dyeing method of 3DP clothes.Design/methodology/approachIn this regard, the thermoplastic polyurethane (TPU) was applied during the process of 3DP. Then, the imitation twill weave (ITW) was printed with fused deposition modeling (FDM) technology using TPU and the suspension of Disperse Blue 2BLN (as a dye) was prepared. After that, the single factor analysis and orthogonal experiment of dyeing were combined to obtain the optimized dyeing process. And then, ITW fabrics were dyed through the weak acid-low temperature dyeing method. In the end, in order to discuss the wearability of ITW fabrics, the dyeing experiments, including permeability, wrinkle recovery angle, bending rigidity, crock fastness and washing colorfastness were carried out.FindingsThe surface morphology of TPU before and after spinning was established by field emission scanning electron microscopy (FE-SEM), which was confirmed the surface of TPU getting smoother after spinning. The wearability of the fabric after dyeing was not affected compared with before dyeing. Moreover, both colorfastness grades were above 4–5 with high colorfastness.Originality/valueThe article provides a method for 3DP dyeing, which can solve the problem of a single color. And the wearability demonstrates that 3DP fabrics after dyeing-based TPU have more value for clothing than before dyeing.

Biocolorant for Leather Dyeing Applications: An Eco-benign Evaluation of Natural Coloring Agent

Exploration of biocolorant in leather industry is explored widely owing to its environmental limitation. Besides, employing synthetic dyes in leather process requires high end of pipe treatment due to their complex chemical structure. Therefore, an attempt has been made on exploiting madder root dye (Rubia cordifolia L.) for leather dyeing application. The effect of varying pretreatment regimen on madder colorant extraction, chemical characterizations (including UV-Vis, IR, particle size, zeta potential value, and thermal studies) and optimum operating leather dyeing conditions are studied. The results revealed dissolving medium pH 5, 100oC, and 60 min duration of extraction is optimum. Thus, obtained dye characteristics showed maximum absorption peak at 460 nm, with an average particle size of 166 nm. It also shows a negative zeta potential value of -5.31 which is indicative for dyeing application. The optimum leather dyeing is found at leather pH 5.5, 10% dye concentration and 4 h duration. At optimum dyeing parameters it shows good fastness, perspiration, organoleptic properties without affecting the physical characteristic. Novelty of the present research would lead to develop eco-dyeing method in leather manufacture. Moreover, the study unravels a new application of eco-benign dye to achieve sustainable process.

Ultrasonic Dyeing of Polyester Fabric with Azo Disperse Dyes Clubbed with Pyridonones and Its UV Protection Performance

The textile sector is closely linked to environmental pollution as a result of the use of toxic chemicals and their disposal in liquid waste, which negatively affects for the environment. Moreover, textile industries, especially wet processing, consume a large amount of energy, water, and chemical auxiliaries. Therefore, there is an urgent need to find a solution that takes the problem of environmental pollution into account. Considering ultrasound as an environmentally safe alternative for dyeing polyester fabrics with the disperse dyes that we have prepared before, the comparison between the ultrasonic dyeing method and conventional dyeing at low temperatures was investigated. Dye exhaustion on polyester fabrics and fastness properties such as the washing, rubbing, light, and perspiration of all of the dyed fabrics were performed by two dyeing methods. Additionally, the ultraviolet protection factors (UPF) for dyed polyester fabrics were evaluated.

Discoloration and Degradation of Bamboo under Ultraviolet Radiation

Light is one of the most adverse factors for bamboo deterioration and causes surface degradation and discoloration. The study was carried out to initiate efficient and effective photodiscoloration to modify and enrich bamboo colors that may be applied to bamboo dyeing. Different types of bamboo samples commonly used in the industry were studied experimentally under two types of ultraviolet (UV) light. Effects of light sources, radiation time, and distances on discoloration and discoloration mechanism were systematically studied. For both UV 313 and high-pressure mercury light, the bamboo surface turned red-yellow, and color parameters including Δ E , Δ a , Δ b , and C rapidly increased first and then stabilized for long time, while Δ L showed a similar trend, except for the final decrease. Compared with UV 313, high-pressure mercury lamp light was highly efficient and took less time to induce discoloration. Heat treatments darkened the bamboo color and slowed down photodiscoloration, and the higher temperature led to more photostability. The color change of bamboo scrimber under UV radiation was less and slower than that of untreated bamboo due to high density and heat treatment, and the dark carbonized scrimber changed less than that of the light carbonized scrimber. Relatively high contents of isovanillin, syringaldehyde, β-hydroxypropiovanillone, p-hydroxybenzaldehyde, and syringic acid were identified by GC-MS, and syringaldehyde, 2,6-dimethylbenzoquinone, and 3-hydroxy-4-methoxybenzoic acid were identified by HPLC-MS from a bamboo discoloration layer after high-pressure mercury lamp radiation. These products all contained a conjugated double bond and were conjectured to be degraded from lignin or aromatic extracts. Particularly, 2,6-dimethylbenzoquinone which contained a cyclohexenedione structure without benzene rings, was more chemically stable than other conjugated double bonds with benzene rings, and was supposed to be the final product (chromogenic group) during bamboo photodegradation. Untreated or light-colored bamboo under high-energy UV light initiated highly efficient and effective photodiscoloration, and UV light is recommended for being applied to industrial bamboo dyeing. Compared with traditional chemical dyeing, the photoinduced dyeing method has no chemical addition and is easy to operate and environmental-friendly.

Introducing Deep Eutectic Solvents as a Water-Free Dyeing Medium for Poly (1,4-cYclohexane Dimethylene Isosorbide Terephthalate) PICT Nanofibers

Water, one of the most priceless sources of life, is becoming dangerously threatened and contaminated due to population growth, industrial development, and climatic variations. The drainage of industrial, farming, and municipal sewage into drinking water sources pollutes the water. The textile processing industry is one of the major consumers of water. Herein, the idea of water-free dyeing of electrospun poly (1, 4-cyclohexane dimethylene isosorbide terephthalate) PICT nanofibers is proposed. For this, two different deep eutectic solvents (DE solvents) were introduced as an alternative to water for the dyeing of PICT nanofibers in order to develop a water-free dyeing medium. For this, C.I. disperse red 167 was used as a model dye to improve the aesthetic properties of PICT nanofibers. PICT nanofibers were dyed by conventional batch dyeing and ultrasonic dyeing methods to investigate the effect of the dyeing technique on color buildup characteristics. Dyeing conditions such as dyeing time, temperature and, dye-concentration were optimized. Morphological and chemical characterization observations revealed a smooth morphology of dyed and undyed PICT nanofibers. The ultrasonically dyed nanofibers showed higher color strength and increased tensile strength compared to conventionally dyed nanofibers. Further, the consumption of electrical and thermal energy was also calculated for both processes. The results confirmed that the ultrasonic dyeing method can save 58% on electrical energy and 25% on thermal energy as compared to conventional dyeing.

Dyeing of Cotton Fabric with Natural Dye Extracted from Egyptian Cotton Leaves

Cotton leaves have been used to extract natural dye for dyeing of Egyptian cotton variety Giza 86 fabric and its blend with polyester 50:50, using different mordants such as iron (II) sulfate, copper (II) sulfate, and alum. The exhaust dyeing method was utilized using the pre-mordant technique. It is observed that both fabric samples can be dyed in different colors and depth of shades with Cotton leaves dye. Iron (II) sulfate ensures the best light fastness. Improved light fastness is obtained using abovementioned lower amounts of iron (II) sulfate and copper (II) sulfate. Alum is found to be less effective than iron (II) sulfate and copper (II) sulfate on the light fastness. As a novel alternative and potential natural dye, Cotton leaves extract solution can be used to get various colors and shades with satisfactory fastness properties. The mordanted and un-mordanted fabric samples were tested for their dyeing performance in terms of color parameters K/S, (L*), a*, b*, (C*) and (H*), and fastness properties (wash, perspiration, light and rubbing fastness) were studied. The samples showed high color strength, and high fastness properties. These results are very important for industrial application and with the production of a natural dye as an inexpensive source from cotton leaves as a by-product. Another objective is to increase the production of eco-textile garments with a good price for the Egyptian customers.