Study on the dyeing of wool fabrics with Phytolacca berry natural dyes

Dyeing of wool fabrics with natural dyes from Phytolacca berries has been studied. The effect of dye concentration, dye bath pH, dyeing time and temperature were discussed. The influence of chitosan application on the dyeing properties of wool fabrics was investigated. The SEM photographs of chitosan treated wool fabrics clearly depict the deposition of chitosan on the fibers. The effect of chitosan concentration, dye bath pH, dyeing time and temperature has been studied by orthogonal experiment. It has been proved that the dyed wool samples pretreated by chitosan have higher color fastness, faster dyeing rate, and better antibacterial properties compared with untreated ones.     

Natural dyeing with black cowpea seed coat. I. Dyeing properties of cotton and silk fabrics

A new trial to determine the dyeing properties of cotton and silk fabrics with a black cowpea seed coat as crop waste was investigated. The natural dye anthocyanins were extracted from a black cowpea seed coat in an aqueous solution and used to dye silk and cotton. The optimal conditions for colorant extraction were an aqueous solution of a dried seed coat of black cowpea in a 1:10 liquor ratio at 70 °C for 4 hours with pH of 4. The best dye-uptake of silk and cotton fabric were obtained when the pH was 3.5 and 3.0 respectively, the temperature was 80 °C for 1 hour and the liquor ratio of black cowpea was 1:20. Different colors as dusky brown, brown, faint yellow, light green, reddish brown, cyan and green could be obtained using a various kind of mordants. The depth and brightness of color tones were affected by different dyeing and mordanting pH conditions. The colors of the fabrics were examined using a computer color matching system in terms of the K/S values and CIELAB color-difference values. The dyeing was evaluated using standard light, wash and heat fastness tests. Good wash and heat fastness were obtained but the poor light fastness indicated the need for improvement to fulfill the requirement for textile applications.     

Modification of polypropylene fibers by electron beam irradiation. I. Evaluation of dyeing properties using cationic dyes

The dyeing properties of hydrophobic polypropylene fibers using cationic dyes were investigated to improve dyeability by electron beam irradiation and sulfonic acid incorporation. The color strength of polypropylene fibers after irradiation was examined according to the dyeing conditions including the pH of the dyebath, absorbed doses, and the introduction of a functional group to the fiber substrate. The best dyeing result was obtained when polypropylene fibers incorporated by sulfonic acid group after electron beam irradiation were dyed with cationic dyes at alkaline conditions and 30∼75 kGy irradiation ranges.     

Effect of using cold plasma on dyeing properties of polypropylene fabrics

The low temperature plasma (LTP) technique is used widely to modify polymer and textile materials. This paper describes the development of a plasma system for textile treatment. Polypropylene (PP) has a very low value of the surface free energy (approximately 20–25 mJ/m²). Due to low surface energy, Polypropylene has very weak hydrophilic properties. By controlling the plasma variables, such as the nature of gas, the discharge power, the pressure and the exposure time, a great variety of surface effects can be generated. In this paper, we report the effect of cold plasma of O₂ and N₂ gases at various time of exposure on the dyeing and physical properties of PP fabrics. The results show a significant increase in the color depth upon dyeing after treating PP fabrics with low temperature plasma of O₂ and N₂. For comparing the amount of fabrics dye exhaustion, we have used reflective spectrophotometer. The morphology of the modified surfaces has also been investigated using scanning electron microscopy (SEM). And also FTIR was used to examine the functional groups of the corresponding samples.     

An investigation of continuous finishing and dyeing on the mechanical properties and handle of cotton fabrics

In this paper, the effect of continuous finishing-desizing, scouring, bleaching and dyeing of woven cotton fabrics on the low stress mechanical and surface properties has been studied. The cotton fabric properties were measured by the famous KES-FB system. The handle of the finished fabrics were calculated by the handle evaluation programme. The results showed that the mechanical properties changed significantly by the desizing and gradually by the scouring, bleaching and dyeing processes.     

Preparation of nano disperse dyes from nanoemulsions and their dyeing properties on ultramicrofiber polyester

Six nano disperse dyes were prepared using corresponding O/W nanoemulsions which were obtained with sodium laurylsulphate and caprylic triglyceride. The average particle size of the dyes prepared were in the range of 110–130 nm. Exhaust dyeing using nano dyes resulted in low exhaustion yields of 17–26 % on regular polyester fiber and 28–38 % on ultramicrofiber polyester. The observed low exhaustion yields of nano disperse dye can be explained by the solubilization of dye particles into surfactant micelles as well as the high stability of the nanoemulsions, these might reduce the capacity of dye uptake onto the fibers. However, higher K/S values of dyeings with nano dyes on ultramicrofiber sites compared to those on regular polyester sites suggested their potential to be more efficient dyes for finer denier microfiber polyesters.     

Synthesis of cationized anthraquinone dyes and their dyeing properties for meta-aramid fiber

Due to compact structure of meta-aramid fiber caused by the intermolecular hydrogen bondings of amide groups, the degree of crystallinity increased, thus its poor dyeing properties arises. Among commercial dyes used in many previous researches, the basic dyes showed comparatively higher exhaustion yields as comparing to those of disperse dyes and acid dyes. The anthraquinone moiety was adopted for good performances of light fastness on meta-aramid fiber. In this study, eight of anthraquinone dye was synthesized. The three of them were obtained from chloro-anthraquinone, by Ullmann reactions with the corresponding heterocylic residues such as morpholine and one of them was obtained from lueco quinizarine by condensation with the corresponding heterocylic residues. The others were prepared by quaternization from dyes above. The synthesized disperse and cationic dyes were dyed on meta-aramid fibers and investigated for their build-up dyeing properties and wash fastness.     

Synthesis and spectral characterization of novel azomethine disperse dyes derived from pyrazolone moiety and their dyeing performance on polyester fabrics

A series of new azomethine dyes based on pyrazolone system have been synthesized via different routes. The solvatochromism for the dyes was evaluated with respect to spectroscopic properties in various solvents. The dyes were applied as disperse dyes on polyester fabrics and gave shade poor to excellent light fastness, washing, perspiration, sublimation, and rubbing fastness properties. Also the position of color in CIELAB coordinates (L*, a*, b*) and K/S value were investigated.     

Properties of basic dyes on polyacrylonitrile treated m-aramid fabrics

Treatment of polyacrylonitrile (PAN) onto m-aramid fabric was carried out by pad-dry-cure method using dimethylformamide (DMF) dissolved acrylic fiber solution. The obtained PAN treated m-aramid fabric was dyed using exhaustion method with basic dyes. The effect of PAN treatment on fabric stiffness property was acceptable with acrylic fiber solutions ranging from 1 wt% to 4 wt%. Whilst, more than 4 wt% PAN treated fabrics exhibited undesirable stiffness. The dyeing results showed that PAN treated m-aramid fabrics exhibited a significant increase in color strength when compared to untreated fabric, arising from an increase in anionic dye sites (styrene SO₃ ^? group). Wash fastness was comparable to that of untreated fabric, indicating the strong interaction between dye molecules and the PAN. Rubbing fastness of treated fabrics was not affected by treatments with PAN concentrations lower than 4 wt%. Further increase in PAN concentration led to poorer rubbing fastness property due to the problem of surface dyeing. For light fastness, the PAN treatment failed to improve the light fastness property which is the main disadvantage of basic dyeing of aramid fabric. Finally, in case of PAN treatments with the range of 1 wt% to 4 wt%, the flame retardancy property of PAN treated m-aramid fabrics was found not affected by the percent add-on. However, above 4 wt% PAN treatment, the flame retardancy performance became deteriorated.     

Dyeing properties of the disperse dyes containing cyano group based on benzisothiazole for polyester fabrics under alkali condition

One step dyeing of polyethylene terephthalate (PET) fabrics combining pretreatment and dyeing under the alkali condition was developed for cleaner production. One step dyeing of PET fabrics required that the dye used has good acid and alkali stability. In this paper, dyeing properties of three azo disperse dyes containing cyano group based on benzisothiazole, 3- (4-N-ethoxyl-N-cyanoethyl -phenyldiazenyl)-5-nitro-2,1-benzisothiazole (D1), 3-(4-N-ethyl-N-cyanoethyl- phenyldiazenyl)- 5-nitro-2,1-benzisothiazole (D2), and 3-(N-benzyl-N-cyanoethyl- phenyldiazenyl)-5-nitro-2,1-benzisothiazole (D3), were investigated under alkali condition. The results showed that polyester fabrics could be well dyed with D1, D2 and D3 under the acid condition. However, D1 was decomposed while dyeing at the alkali solution. D2 and D3 had excellent color yields under the alkali condition. The acid-alkali stability and the structure change were analyzed by UV-vis spectrum and high pressure liquid chromatography (HPLC). Gaussian 09 program package was used to optimize geometry by B3LYP method and 6-31G (d) basis set. The solvation energy of D1 in water was higher than those of D2 and D3. The electron withdrawn effect of the hydroxyl affected the energy gap of HOMO and LUMO orbits. D2 and D3 showed excellent stability in the strong alkali medium. And the dyed polyester fabrics with D2 and D3 at the alkali condition also had good fastness properties.     

Study on the aging and yellowing properties of sebum-soiled cotton fabrics

The accumulation and autoxidation of residual oily soil from human sebum is regarded as a major reason for the aging and yellowing of clothing and household textiles. In this study, the yellowing degree of cotton fabrics soiled with human sebum components and aged under various environmental conditions (various temperatures, humidities and light intensities etc.) were investigated. The representative sebum components including olive oil, squalene, oleic acid and cottonseed oil were selected and their chemical changes were studied by FTIR analysis. The results showed that, olive oil, squalene, oleic acid and cottonseed oil could caused more significant fabric-yellowing than other components in human sebum, and the yellowing degree could become higher with increasing temperatures, humidities and/or light intensities of aging environments. The chemical structures of olive oil, squalene and oleic acid changed remarkably after aging treatment. The aging products contained hydroxyl groups and carbonyl groups, and the conjugated C=O group was considered to be the chemical species leading to the yellowing of sebum-soiled fabrics.     

Effect of pigment particle character on dyeing performance of cotton fabrics

The cotton fabrics were dyed by exhaust method using the pigment dispersions as colorant, and meanwhile the effects of particle character on dyeing performance were further investigated. The results showed that the larger zeta potentials, the higher K/S value, pigment uptakes, rubbing and washing fastness of the dyed cotton fabrics were. Adsorption isotherms were belonging to Langmuir type when zeta potentials were about 0.46 mV and 31.39 mV respectively. The cotton fabrics that dyed by the pigment dispersions with small particles had high K/S value, rubbing and washing fastness. The chemical structure of pigment had little influence on pigment uptakes, and all kind of pigment dispersions reach to 98 % uptakes after 30 min but exhibit various uptake rates at initial stage.     

Application of acacia natural dyes on cotton by pad dyeing

Coloration of textiles, traditionally achieved using natural dyes, commonly employs synthetic dyes at the industrial level. A revival of commercial interest in natural dyes has opened several research avenues. This paper investigates the application by padding of cotton fabric with 10 g/l of two natural dyes derived from the Acacia plant family. Three mordanting techniques were studied; of which post-mordanting produced the most even shade. Among the two mordants investigated, the use of copper sulfate resulted in a level beige shade at 15 g/l concentration while ferrous sulfate performed best at 5 g/l yielding a yellow-grey shade. An optimum process-sequence for the copper sulfate mordant was “pad (dye)→dry→steam followed by pad (mordant)→steam→dry”, and for ferrous sulfte it was “pad (dye)→steam→dry followed by pad (mordant)→steam→dry”. Typically a change in mordant resulted in a different shade with the same dye. The study concluded that padding is a readily adaptable process for the dyeing of cotton using natural dyes and acceptable fastness in shades can be obtained.     

Reactive dyeing of meta-aramid fabrics photografted with dimethylaminopropyl methacrylamide

Aramid fibers have been known to difficult to dye with conventional dyes and dyeing techniques because of its extremely high crystallinity and compactness. In order to make the aramid fibers dyeable to a bright color in deep shade, meta-aramid fabrics were photografted under continuous UV irradiation with dimethylaminopropyl methacrylamide (DMAPMA) and benzophenone as a monomer and a hydrogen-abstractable photoinitiator respectively. Several factors affecting the photografting treatment of the meta-aramid fabrics were investigated including monomer and photoinitiator concentrations. ATR, ESCA and SEM analysis indicated significant alterations on the chemical structure and atomic composition of the photografted fabric surface and the fabric surface was covered with the grafted polymers. While the pristine meta-aramid fabrics showed no appreciable dyeability to the α-bromoacrylamide type reactive dyes, the grafted aramid fabrics showed the remarkably enhanced dyeability to the reactive dyes, which was proportional to the graft yield indicating the covalent bond formation between the dyes and the secondary amino groups in the grafted DMAPMA. In case of C.I. Reactive Red 84, a K/S value of 14.8 can be obtained with the grafted meta-aramid fabrics with a graft yield of 7.6 % (w/w). Also and the color fastness properties of the dyed fabrics was excellent in the conditions of washing, rubbing and solar irradiation.     

Isolation, identification and dyeing studies of betanin on modified acrylic fabrics

Mature red fruits of Opuntia ficus-indica contain two soluble pigment, betanin and indicaxanthin. The optimal conditions for dye extraction were to mix 50 g of juice from cactus pears with 100 mL of acidified water as solvent for dye extraction. Two main dyes were purified from the pigment extract by chromatography and identified by UV-vis, HPLC and LC-MS techniques as indicaxanthin (15 mg per 100 g) and betanin (280 mg per 100 g). The effect of dye bath pH, salt concentration, dyeing time and temperature was studied. The optimal conditions for dyeing modified acrylic fabrics with betanin dye were carried out at 50 °C for 45 min at pH 5. Un-mordanted samples have good properties of water and washing fastness. Mordant CoSO₄ was found to give good light fastness (rating 5).     

LED-UV grafting of vinylsulfone dyes onto photo-oxidized wool fabrics

Photografting coloration of wool was carried out under UV-LED irradiation at room temperature using aqueous vinylsulfone dye solution containing vinylsulfonic acid as a comonomer. UV-LED irradiation of the 395 nm emission is more energy efficient, less damaging to the dyes, and much safer to human eyes compared with polychromatic mercury UV lamps. However, in case of the UV-LED lamps, the wool needs to be photo-oxidized either by UV/ozone or polychromatic UV irradiation before the dye photografting. The surface treatments increased the sulfur and oxygen contents in the modified wool surfaces. While the optimally photografted wool fabrics under the UV-LED lamp yielded a K/S value of 9.9, the K/S of the grafted wool increased to 25.2 and 13.6 after the UV/Ozone or polychromatic UV preoxidation at UV energies of 10.6 J/cm² and 25 J/cm² respectively. The color fastness properties of the photografted fabrics were far better than with those of the conventionally reactive-dyed fabrics, implying that the high-molecular-weight photografted dyes seemed to be more durable than the low-molecular dyes.     

Union dyeing of the photografted PET/wool blend fabrics with dimethylaminopropyl methacrylamide

Dimethylaminopropyl methacrylamide (DMAPMA) was grafted onto PET/wool blend fabrics by continuous UV irradiation. Union dyeing of the photografted fabrics was investigated using three reactive dyes of α-bromoacrylamide reactive groups. The influence of grafting yield, DMAPMA concentration, NaCl amount, pH value, and dyeing temperature on the dyeability was evaluated. The dyeability of both PET and wool components was improved significantly by the DMAPMA photografting and successive reactive dyeing. Although the dyeability of the PET component in the blend substantially was improved with higher grafting, equal dyeability between PET and wool was difficult to achieve due to more facile grafting and higher reactivity of the wool component compared with the modified PET component. However, the color fastness of the PET/wool blend fabric was excellent for all three colors. This study may offer a way to achieve union dyeing of PET/wool blend fabrics.     

Dyeing of synthetic fabrics in water using azoic dyes based on boronic acid derivatives

Development of water-soluble dyes for the dyeing of different textile fabrics is essential for the textile industry due to ecological and economical reasons. In this study, a series of new azoic dyes were prepared by diazotization reaction between the phenyl boronic acid and different aniline derivatives, and their dyeing capacity in aqueous solution was evaluated. The synthesized boronic azo dyes present good water solubility and can dye polyamide (nylon), wool, silk, and cellulose acetate fabrics. The effect of factors such as concentration of dye, dyeing temperature, and pH on the level of color strength (K/S) was studied. The dyeing results showed that higher color strength K/S (about 16) and fastness properties (about 4/5) with boronic acid dyes were achieved at higher temperatures avoiding the use of surface agents, mordants, and other polluting chemical additives.     

Application of liquid organic salt to cotton dyeing process with reactive dyes

Reactive dyes are used widely in cotton dyeing process. Reactive dyeing uses high amounts of inorganic salts to accelerate dye exhaustion. These salts are then discharged to the effluent, leading to serious environmental problems. Biodegradable organic salts can alternatively be used in the dyeing process. In this paper, a new liquid organic salt was synthesized by acid-base neutralization, which was used to replace inorganic salts in reactive dyeing. Dye exhaustion in organic salt dyeing was similar to the values in conventional dyeing. However, dye fixations were slightly lower in organic salt dyeing than in conventional dyeing. The washing fastness of dyed fabrics with organic salt was excellent. Experimental results showed that dye exhaustion reached the maximum value when the concentration range of organic salt was from 20 g/l to 40 g/l. In addition, the optimal alkali concentration in organic salt dyeing was found to be about 30 g/l. These parameters suggested organic salt could replace inorganic salt in reactive dyeing process.     

Optimization of the processing conditions and prediction of the quality for dyeing nylon and lycra blended fabrics

This paper is intended to determine the optimal processing parameters applied to the dyeing procedure so that the desired color strength of a raw fabric can be achieved. Moreover, the processing parameters are also used for constructing a system to predict the fabric quality. The fabric selected is the nylon and Lycra blend. The dyestuff used for dyeing is acid dyestuff and the dyeing method is one-bath-two-section. The Taguchi quality method is applied for parameter design. The analysis of variance (ANOVA) is applied to arrange the optimal condition, significant factors and the percentage contributions. In the experiment, according to the target value, a confirmation experiment is conducted to evaluate the reliability. Furthermore, the genetic algorithm (GA) is combined with the back propagation neural network (BPNN) in order to establish the forecasting system for searching the best connecting weights of BPNN. It can be shown that this combination not only enhances the efficiency of the learning algorithm, but also decreases the dependency of the initial condition during the network training. Most of all, the robustness of the learning algorithm will be increased and the quality characteristic of fabric will be precisely predicted.