The effect of polyhydroxyurethane on dyeing of cellulosic fabrics with direct and reactive dyes

Dye yields and fastness properties are reported for direct and reactive dyes using a modified dyeing solution with polyhydroxyurethane. Excellent dye yields and colour fastness properties were obtained without the use of electrolytes, multiple rinsing or fixation agents, which are normally employed in cotton dyeing. From the results, it was found that polyhydroxyurethane media exhibit better dyeability and fastness than the normal aqueous media. Dye adsorption in polyhydroxyurethane media was much higher than in other aqueous systems. The dyed samples showed good hot pressing and washing colour fastness properties within the color change range. The excellent solubility of these dyes in the polyhydroxyurethane aqueous solution makes them ideal for use in exhaustion dyeing.     

The dyeing of cellulosic fabrics by simultaneous application of azoic components and vinylsulphone or monochlorotriazine reactive dyes

The paper reports preliminary work on the dyeing of cellulosic fabrics by applying vinylsulphone or monochlorotriazine reactive dyes simultaneously with an azoic coupling component.     

New thickening agents for reactive printing of cellulosic fabrics

Four adducts were prepared by polymerizing acrylic acid (AA) in presence of either a pyrodextrin (D) or gum Arabic (GA), and termed as PAA/D₁, PAA/D_2, PAA/GA_1, and PAA/GA₂. These adducts were utilized as thickeners in reactive printing of cotton fabric in comparison with Na‐Alginate. Printing was carried out at different conditions including: NaHCO₃ concentration (0–40 g/K), urea concentration (0–200 g/k), steaming temperature (100–130°C) and time (5–35 min). At optimal NaHCO₃ concentration (30 g/K) the depth of shade of the prints, expressed as K/S values, depended on the nature of the thickener used, and followed the descending order PAA/D₂ > PAA/GA₁ > Na‐Alginate ?PAA/D₁ ≥ PAA/GA₂. Accordingly, PAA/D₁ and PAA/GA₂ were omitted in subsequent trials. Optimal printing conditions were found to be NaHCO₃ concentration (30 g/K), urea concentration (100 g/k), steaming temperature (110°C), and time (15 min). The apparent viscosity of a printing paste, as well as both of K/S value and fastness properties of a print were governed by the nature of the reactive dye and type of thickener. Storing of a printing paste up to 7 days resulted in a decrease in its apparent viscosity along with a slight reduction in K/S value and a little variation in some fastness properties of prints. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4430–4439, 2006     

Reactive dyeing of cellulosic fibers: Use of cationic surfactants and their interaction with reactive dyes

Cotton fabrics were dyed with three reactive dyes, C.I Reactive Blue 263, C.I Reactive Red 269, and C.I Reactive Yellow 208, after pretreatment of the fabrics with three alkyl trimethyl‐ammonium bromides (tmabs) having 12, 14, and 16 carbon atoms in the alkyl chain. The pretreated samples were dyed with standard dyeing methods using conventional, reduced amounts of electrolyte, and no electrolyte. Pretreatment with the three cationics (tmabs) resulted in an increase in dye exhaustion with all dyes used, whereas total dye fixation was lower for both red and blue dye and equal for the yellow, when compared to the reference untreated samples dyed according to the same standard dyeing method. The interaction between dodecyl trimethyl‐ammonium bromide and the three dyes was studied and the stoichiometry of the various dye/dodecyl trimethyl‐ammonium bromide (12‐tmab) complexes formed has been deduced. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Foam properties and application in dyeing cotton fabrics with reactive dyes

The foam dyeing of cotton fabric with CI Reactive Red 120 has been studied as a low‐add‐on technology. The foamability of different types of foaming agent and the stability of foam stabilisers were compared. Factors influencing foam dyeing, including wet pick‐up, fixation agent, foam stabiliser, and blow ratio, were evaluated by colour strength and dye fixation rate. Wet pick‐up, fixation agent, and foam stabiliser were found to be the main factors in the foam dyeing process. The comparative build‐up properties, dyeing properties, and total consumption between foam dyeing and conventional dyeing were assessed. The results indicate that, in foam dyeing, the dyestuff has a better build‐up property, the dyed fabric has excellent wash and rub fastness, and large amounts of water and energy are saved. Moreover, foam dyeing requires smaller dosages of chemical agents and reduces the difficulty of effluent treatment.     

Bio-polishing of cellulosic fabrics

Various treatments are available to reduce pilling and improve fabric softness. One new and permanent treatment is the bio-polishing process. Michael Wadham tells us more.     

交联改性壳聚糖在棉织物活性染料染色中的应用

采用交联改性降解壳聚糖对棉织物进行接枝改性,考察壳聚糖接枝改性对棉织物雷马素活性染料染色性能的影响.结果表明:棉织物经壳聚糖改性后,增加了织物表面对染料阴离子的亲和力和固着力,上染率和K/S值都有所提升,其固色率也有很大提高,均达80%以上;经雷马素红RR和雷马素黄RR染色后,改性棉织物的干、湿摩擦牢度和耐皂洗褪色同未改性棉织物一样,分别为4、3~4和4级,耐皂洗沾色降低半级,为3~4级.用雷马素蓝RR染色后,改性棉织物干摩擦牢度提高半级,达4级,湿摩擦牢度和耐皂洗等级同未改性棉织物一样,分别为3~4和4级.     

Salt-free reactive dyeing of betaine-modified cationic cotton fabrics with enhanced dye fixation

Novel cationic cotton fabrics were prepared by an efficient and simple one-step pad–dry–bake pretreatment process with betaine as cationic reagent. Ester bonds formed between cotton fibers and betaine hydrochloride were proved by Fourier transformed infrared attenuated total reflection(FTIR-ATR) spectra. Moreover, the properties of the cationic fabrics, including X-ray Diffraction(XRD), tensile strength and whiteness and yellowness index,were investigated in comparison with that of the untreated ones. The cationic fabrics were applied in salt-free dyeing of C.I. Reactive Red 195, C.I. Reactive Yellow 145 and C.I. Reactive Blue 19. Different dye fixation processes were applied and compared for untreated and cationic cotton. Dye fixation and color fastness properties of the dyes were tested, and the results presented that dye fixation on the cationic fabrics in the absence of salt was improved with satisfactory light fastness property and applicable wash and rub fastnesses.     

Acid dyeing isotherms of cotton fabrics pretreated with mixtures of reactive cationic agents

Reactive cationic agents, phenylmonochlorotriazinyl and epoxypropyl, are used for cotton pretreatment using a pad–dry–curing technique. The dyeability of cationised cotton fabrics using CI Acid Red 1, determined spectrophotometrically for the residual dyebath, has been dependent on the cationic agent concentration and the appropriate mixture used. Comparative sorption isotherms, rate of dyeing at different temperatures, standard affinity, entropy and heat of dyeing for three different pretreated fabrics have been calculated and discussed. The equilibrium data obtained were fitted by the Langmuir isotherm model, allowing the corresponding sorption parameters to be determined.     

Application of chitosan/nonionic surfactant mixture in reactive dyes for dyeing wool fabrics

The feasibility of wool fabrics pretreated with a chitosan/nonionic surfactant mixture and dyed with reactive dyes was studied. The results showed that the presence of the chitosan/surfactant improved the application to wool, which greatly enhanced the color strength when dyed at 50°C but little change was observed when dyed at 80°C. The higher the concentration of chitosan/surfactant added, the greater was the color strength of the dyed wool fabrics. The amounts found to be optimum for dyeing were 0.5% chitosan and 1.0% surfactant. The washing fastness of the dyed wool fabrics was in the range of grades 4–5, the dry rubbing fastness was in the range of grades 4–5, and the wet rubbing fastness was in the range of grades 3–4. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2859–2864, 2001     

Thermal analysis of different cellulosic fabrics

Thermal behavior of different cellolusic fabrics was investigated in air and nitrogen by TG, DTG and DTA. Kinetic parameters based on weight loss for the initial and major stages of thermal degradation were determined. The weight loss in the TG curve for the cellulosic fabrics can be divided into four stages. In general, E_a values in air are lower than those in nitrogen, and the enthalpy changes as well as rates of degradation in air are much larger than those in nitrogen. This indicates that the thermal degradation of cellulosic fabric is promoted by oxygen. The E_a values of regenerated cellulose fabrics (viscose and modal) at the rapid weight loss stage are relatively higher than those of the cotton and linen fabrics. The raw cotton has the lowest E_a of all cellulosic fabrics, but its frequency factor and rate of weight loss are also the lowest. The thermal behavior of linen is similar to that of the raw cotton. Bleached, boiled and antibacterially finished cotton fabrics are also compared. Thermal behavior and kinetic parameters for the different cellulosic fabrics are discussed in the light of their structural characteristics, including degree of polymerization, crystallinity, crystalline form, orientation and morphology. Also the effects of the impurities and additives on the fabric are considered. © 1996 John Wiley & Sons, Inc.     

Characterisation of novel regenerated cellulosic,viscose, and cotton fibres and the dyeing properties of fabrics

There is a global demand for constant increase in the production of textile fibres. Currently, the market for cellulosic fibres is dominated by cotton and viscose fibres. However, new alternative cellulosic fibres are being sought to meet the growing demand. The dyeing properties of novel fibres aiming at the marketplace are among the properties that determine their applicability to textiles. Recently, a novel process for producing cellulosic fibres, the Biocelsol process, has been scaled up so that the spinning of yarn from Biocelsol fibres is now possible. In this study, the reactive dye Levafix CA Blue was applied to cellulosic fabrics made from viscose, cotton, and Biocelsol yarns. The crystalline structure and morphology of the fibres were studied by Fourier transform infrared spectroscopy and field‐emission scanning electron microscopy. The crystalline structure and morphology of the Biocelsol fibres resembled those of viscose fibres, but, owing to higher water absorption, the Biocelsol fabric had a higher dye exhaustion. The colour yield of the Biocelsol fabric was 62% and 41% higher than that of cotton and viscose fabrics respectively, suggesting that less dye is needed to gain a shade in Biocelsol fabric than in viscose and cotton fabrics.     

Controlled coloration: a success strategy for the dyeing of cellulosic fibres with reactive dyes

The impact of improving the rate of right-first-time production on productivity and profitability for a batchwise dyehouse processing cellulosic fibres is reviewed. The measurement and level of performance required from reactive dyes to support right-first-time production is defined in the form of a reactive dye compatibility matrix (RCM). The application of the RCM as a diagnostic tool in dye selection and process design is outlined.     

Interaction of vinylsulphone reactive dyes with cellulosic fabrics. Part 2-dye associations and dyesurfactant interactions

The ability of reactive dye molecules (CI Reactive Red 180 and CI Reactive Yellow 23) to undergo self-association and to associate with different surfactants has been examined spectrophotometrically. The stability constants K_DS of the dye-surfactant complexes were calculated at dye:surfactant ratios varying from 1:0 to 1:10 and for different surfactant types (anionic, zwitterionic, nonionic and cationic). Dye uptake on viscose fibre observed for a dye:surfactant molar ratio of 1:0.5 was found to be related to K_DS values.     

Modification of cellulosic fabrics to impart flame retardancy properties

Graft copolymerization of dimethylaminoethyl methacrylate (DMAEMA) onto cotton‐cellulose in the fabric form was carried out using a cellulose‐thiocarbonate‐ammonium persulphate redox initiation system. Effects of the concentration of the monomer, effect of liquor ratio, grafting time, and temperature were studied. The results point out the following important aspects of flame retardation of cellulose fabrics. (1) The graft polymerization of DMAEMA can improve the flame retardant properties of cellulose fabrics. (2) Tertiary amine grafted to cellulosic fabrics is suitable for nitrogen compounds that can effectively operate as synergists. The flame retardant properties of the poly‐DMAEMA‐ grafted‐phosphorylated cellulosic materials were found to be excellent even after 25 dry clean washings. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Triazinylamino-alkylphosphonate reactive dyes for cellulosic fibres

A bifunctional reactive bis-phosphonoalkylaminotriazine dye was synthesised by condensing 2 mol of aminoethylphosphonic acid with the commercially available bis-monochloro- s -triazinyl dye, CI Reactive Red 120. A similar but much lower molecular weight dye was prepared by condensing the commercially available dichloro- s -triazine dye, Procion Red MX 8B, with aminomethylphosphonate. A model aryl-phosphonate dye was also prepared by diazotising m -aminobenzene-phosphonic acid and coupling the diazonium salt to R-salt. These dyes were isolated as their free acids and then converted to their ammonium salts. Pad liquors containing dye, cyanamide and ammonium dihydrogen phosphate were applied to cotton fabric. In the case of the bis-phosphonoethylamino- s -triazine dye, very high dye–fibre fixation values (>90%) were achieved using a pad–batch–bake procedure; for the Procion T model dye, the comparative maximum fixation was only modest. In the absence of cyanamide, no fixation could be obtained for the arylphosphonate dye but both bis-phosphonoalkylaminotriazine dyes gave significant fixation.     

Near room temperature dyeing of m-aramid fabrics

Due to their high crystallinity and inertness, the coloration of meta-aramid fiber has been widely confirmed to be difficult. Though substantial improvements have been achieved, the dyeing of this fiber still requires high temperature and long duration for good color strength and shade. In this article, grafting poly(acrylic acid), a polyelectrolyte, onto meta-aramind fibers followed by dyeing via conventional pad-dry-cure technique resulted in good dyeing and a decrease the dyeing time and temperature. Dyed samples that possess industrially acceptable K/S values were produced in 15 minutes at room temperature (25–27 °C) under neutral pH. Dyed samples had good dry and wet crockfastness. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48190.     

The dyeing and printing of silk fabrics

Wth the recent increase in the printing of natural jibres, silk, the ‘queen of fibres’ is again increasing in popularity. Apart from the traditional indusby of printing scarves, ties and evening gowns there is an increasing trend of more silk in the ‘young’ fashion areas. Dyers and printers of silk have, for obvious reasons, kept their ‘know how’, based on many years of experience, secret and little information on the practical processing of silk has appeared in the technical litemture. The present paper will attempt to reuiew the prepamtion, dyeing and printing of silk based on our experiences in the laboratory, pilot plant and in some cases on practical mill expenience.     

Low-temperature ultrasonic dyeing of silk

Silk was dyed with cationic, acid and metal-complex dyes at low temperatures in the presence of ultrasonic energy for relatively short durations. The results in terms of dye uptake were compared with those obtained by conventional processes run at higher temperatures and for longer dyeing times. It was found that the ultrasonic energy helps in obtaining good fast dyeings, simultaneously conserving energy and reducing the time required for the dyeing process. In some cases the dye uptake was even higher than that obtained by the conventional dyeing procedures.