Dyeing properties of polyamide super-microfibre with disperse dyes

The dyeing properties of polyamide super-microfibres and conventional fibres dyed with disperse dyes have been studied by measuring the adsorption isotherm, the rate of dye uptake, the time of half-dyeing and the amount of equilibrium adsorption. The thermodynamic analysis shows that the adsorption isotherms of super-microfibres follow a Langmuir sorption model. The kinetic results show that super-microfibres have a faster dyeing rate and a higher equilibrium dye uptake compared to conventional fibres. This can be explained by the greater surface area and dye capacity of the super-microfibres. The wash and light fastness properties of the super-microfibres dyed with disperse dyes are lower than conventional fibres.     

Dyeing studies with hydroxyanthraquinones extracted from Indian madder. Part 2: Dyeing of nylon and polyester with nordamncanthal†

Nordamncanthal is an important constituent of the colouring matter extracted from Indian madder roots. Its dyeing properties have never been studied even though the structural characteristics closely resemble those of disperse dyes. In this study, nylon and polyester have been dyed with this colorant. Linear isotherms have been obtained, confirming that the mechanism is similar to that of disperse dyes. The dye has good affinity for both the fibres. Kinetic and thermodynamic parameters have been calculated.     

Thermodynamics of Leather Dyeing II – Dyeing of Hide Powder with Simple Acid Dyes at Various Temperatures

The interaction of two types of hide powder with individual members of a series of pure dye acids has been investigated by determining the distribution of the dye at equilibrium at ten points on the titration curve. Nine dyes were applied to a specially purified hide powder at 0, five at 25, and four at 45C, and many of the experiments were repeated with Official hide powder. Affinities were determined by using Gilbert and Rideal's full equation (I), and from the midpoints of the titration curves. They depend greatly on the basicity of the dye, being –9. 3 to –11–7 kcal/mole for mono–, –14. 2 to –16. 6 for di–, –17. 8 to –23. 3 for tri–, and –22. 3 to –26. 1 for tetrasulphonic acids. Heats of dyeing can be positive at 0–25, but are negative at 25–40, whereas entropies of dyeing are positive at 12–5 and seem to remain positive at 35C. Tentative attempts have been made to correct for neglect of dye aggregation, activity coefficients in solution, and swelling of the fibre.     

Vapour–phase Dyeing of Synthetic–polymer Fibres

Absorption isotherms at high temperatures for some disperse dye vapours and secondary cellulose acetate film have been determined and found to be linear. In order to calculate dye vapour concentrations, two methods have been used for the determination of vapour pressures, and from the results it is shown that disperse dye molecules can associate in the vapour phase. The absorption of dye vapour by polyester fibre in the form of small packages over the range 180–220°C, as well as a laboratory machine that can be used for this purpose, are described. Package dyeing on a larger scale with dye vapour is considered to be possible.     

Dyeing behaviour of Japanese oak silk fibres treated with methacrylamide

Japanese oak silk fibres have been treated with methacrylamide, and the dyeing behaviour when using levelling acid and milling acid dyes has been investigated. Infra-red spectroscopy indicated that a methacrylamide polymer skin was produced on the fibre surface at high levels of polymer add-on. The methacrylamide polymer skin was dyed with the milling acid dye, although not dyed with the levelling acid type. The penetration of the levelling acid dye into the fibres was not interrupted by the polymer skin.     

Dyeing properties of wool treated with liquid ammonia

Wool fibre and fabric have been treated with liquid ammonia and their surface characteristics investigated by means of SEM and ESCA techniques. The treated specimens were dyed with levelling and milling acid dyes. Although no changes in nitrogen content and fibre surface properties were detected, their dyeing rate was increased considerably as was saturation dye exhaustion. Dyeing properties were similar to those of wool treated with low-temperature plasmas by glow discharge. Fabrics treated with liquid ammonia were dyed at various temperatures in the range 30–80°C, and dye uptake was similarly increased.     

Dyeing of wool with temporarily solubilised disperse dyes

Temporarily solubilised disperse dyes derived from aminophenyl-4-(β-sulphatoethylsulphone) have been applied to wool fabric without the use of a levelling agent. By virtue of their characteristic dye structure, excellent levelling properties were observed on wool fabric. Good exhaustion, fixation and fastness test values were also obtained.     

Monolayer Studies of the Mechanism of Disperse Dyeing*

The Langmuir film balance and the Davies surface-film viscous traction apparatus have been used with films of cellulose triacetate alone and in presence of two different disperse dyes; these were C.I. Disperse Red 13, an azo dye having both proton-donating and proton-accepting groups in its molecule, and C.I. Disperse Yellow 13 (methoxybenzanthrone), which has only proton-accepting groups. The results show that a 1:1 complex is formed between either dye molecule and a hexa-acetylcellobiose unit of the cellulose triacetate molecule, and possibly also a complex with an aggregate of the yellow dye. This indicates a face-to-face association of the dye molecules (which are planar) with cellulose acetate. The association is probably a hydrogen-bonding interaction.     

Dyeing of cellulose by direct dye in aqueous sodium alginate solution

Dyeing of cellulose by direct dye in aqueous sodium alginate solutions containing sodium chloride has been studied to interpret thermodynamically the role of sodium alginate on the adsorption equilibrium of dye on cotton. The result has been compared with that of sodium chloride (low-molecular inorganic electrolyte) by an adsorption model on cellulose. We have inferred, by the membrane-equilibrium theory, that the dye has been concetrated into the internal solution of cellulose because of the presence of sodium alginate in the bulk solution.     

Dyeing polyester fibers using the crazing method

As we know, finished polyester fibers are very difficult to dye, especially at low temperature (including room temperature). An exception is processes for dying undrawn fibers. We have studied use of the crazing method to dye polyester fibers at low temperatures with water-soluble dyes not having an affinity for polyethylene terephthalate. We have studied the effect on sorption of cationic dyes from the composition, concentration, and temperature of the adsorption-active medium, and the dye concentration in the dye bath. The results of the study are the basis for developing a production process for obtaining colored special-purpose polyester fibers.     

The Dyeing of Dacron 84 and its Blends with Wool

Dacron 84, a modified basic-dyeable polyester fibre, can be dyed satisfactorily only with a limited range of basic and disperse dyes. A dye-screening procedure is described, and a dye selection is given. Various carriers have been assessed. The costs of different dyeing processes are compared. The dyeing of Dacron 84-wool blends is described, and the effect of processing on the properties of the cloth is mentioned.     

A Practical Use for Dyeing Theory

The general thermodynamic schemes for predicting the amount of dye on the fibre which have been used by other workers are outlined. A new approach is then developed for the complex system of vat dyes on cotton, and the affinities of 14 vat dyes are calculated. The theory is extended to mixtures, and the variables of temperature, amount of salt added, amount of dye added, and amount of reducing agent added required to give a known colour are predicted from the theory. Cotton thread was dyed under different predicted conditions and the resultant matched dyeings are good evidence of the validity of the theory. In addition, the effects of the main dyeing variables on the resultant colour are predicted from the theory.     

The Dyeing of Acrilan with Basic Dyes in the Presence of Benzyl Alcohol*

The dyeing of Acrilan with C.I. Basic Green 4 from water containing benzyl alcohol and benzyl alcohol containing water has been examined. Benzyl alcohol in water acts as a plasticizing agent for the fibre. The plasticizing action of small quantities of water in benzyl alcohol has also been detected and in both systems the rate of diffusion of dye into the fibre is related to the plasticizing action. The equilibrium absorption is a function of the difference between the dyeing temperature (T) and the glass transition temperature (T_g) of the fibre. The differences in the behaviour of the dye in the aqueous and benzyl alcohol dyebaths are related to the degree of dissociation of the dye and the mechanical properties of the fibres.     

Molecular Mechanisms of Disperse Dyeing of Polyester and Nylon Fibres

The kinetics of the dyeing of polyester fibres with disperse dyes have previously been discussed in terms of a model in which the only forces of interaction between dye and polymer are those that give rise to mutual solubility. The rate and extent of dyeing depend on the size and shape of the dye molecules and the detailed structure of the fibre. The concentration profiles of dye within single filaments of polyesters and nylons have now been determined by a new method termed ‘optical sectioning’, in which an image of a filament is scanned by a narrow slit. The dye distributions are found by comparing experimental transmission values with those calculated by a computer for a model system in which various parameters can be adjusted. For the polyester-dye systems the rate constant of transfer of dye from dyebath to fibre (k₁) was the same as the rate constant of diffusion away from the interface (k₂). Some nylon-dye systems, on the other hand, behaved as if k₂ = k₁, whereas others behaved initially as if k₁ = k₂ but later as if k₂ > k₁. Apparent diffusion coefficients were also derived from sorption measurements and were found to fall as the dye concentration in the fibre increased. Measurement of the orientation of the dye molecules by optical dichroism showed that the dye molecules entering the filaments late in the dyeing process were more highly orientated than the earlier ones. The decrease in diffusion coefficient has been interpreted in terms of the observed higher orientation, as resulting from a greater entropy of activation in the diffusion process.     

稀土改性尼龙66染色机理的研究

<正>近几年来,稀土化合物在纤维染色过程中的应用取得了良好效果.随着稀土染色的推广和应用,对稀土染色机理的研究也愈加引起人们的关注.有人在研究锦纶和涤纶稀土染色时提出了分子络合理论,认为在染色过程中,稀土化合物的加入会生成纤维大分子-稀土离子-染料分子复杂的配位体,从而改善了染色效果.     

Dyeing properties of monoazo disperse dyes derived from 4-alkylamidosalicylic acids: equilibrium study

The dyeing equilibria of a set of monoazo dyes derived from 4-alkylamidosalicylic acids on nylon 6.6 have been studied. A Nemst distribution has been obtained indicating the prevailing mechanism of solution of the dye in the fibre Equilibrium depends on the length of the alkyl chain of the dye and on the concentration of dispersant. The latter affects the equilibrium differently according to the hydrophobicity of the dye. Linear relationships between the chain length and ΔHd? and ΔSd? have been found.     

常压沸染工艺下涤纶深染技术的最新进展

随着节能环保要求的逐步提高,普通涤纶高温高压染色工艺正面临严峻考验。然而当前在很多领域,染缸染色仍然是涤纶最主要的着色选择,常压沸染及如何提高竭染率是行业的最大挑战。通过在普通涤纶纺丝中加入美国奥美凯公司全新一代染色增强母粒,将所得纤维与普通涤纶做染色对比,结果显示:添加染色增强母粒的纱线的颜色明显深于普通纱线,染色残液明显比普通纱线染色残液要浅。     

Dyeing with polyaniline synthesis in fibers

Physicochemical aspects of dyeing with polyaniline are considered. It is shown to be possible to attain the first percolation threshold for electrically conducting polyamide fabric. An equation has been obtained for estimating the thermodynamic affinity of the dye for the fiber. Translated from Khimicheskie Volokna, No. 4, pp. 49–52, July–August, 2008.     

Dyeing of nylon 6 and silk fabrics with a model disulphide bis(ethylsulphone) reactive disperse dye

The synthesis of a new reactive disperse dye containing the disulphide bis(ethylsulphone) group is described. The dye has been applied to nylon 6 and silk fabrics at a variety of pH and temperature conditions. Optimum dye exhaustion and fixation were achieved at pH 8 and 130 °C. The results of dyeings on both substrates indicate that the model disulphide bis(ethylsulphone) reactive disperse dye shows a higher degree of exhaustion and fixation on silk than on nylon 6. The fastness and levelling properties on both fabrics were good.     

Dyeing of Texturised Polyester Yarn

The paper describes a study of many factors which play a significant part in the dyeing of texturised-polyester yarn at high temperatures. The variables chosen for study are the selection of disperse dyes to give the desired fastness properties, coverage of dyeing-substantivity differences before, during and at the end of the dyeing process. The effects of different types of dispersing agents on dispersion properties and the selection and behaviour of different types of ‘carrier’ suitable for high-temperature dyeing are also considered, the latter in relation to levelling, dye yields, ability to compensate for small differences in dyeing temperature, coverage of yarn variations, minimisation of dye and oligomer crystallisation at the end of dyeing and the stability of the ‘carriers’ themselves. The formation and behaviour of oligomer have also been investigated. Factors governing the choice of optimum dyeing cycles for polyester yarn are also reviewed.