The Effect of Rate of Flow on the Sorption of Dye by a Nylon Fabric from Aqueous Solutions

The rate of sorption of an acid dye by a nylon fabric is strongly influenced by mass–transfer processes in the liquid phase, even at rates of flow far exceeding those to be expected in existing commercial dyeing equipment. It is suggested that concentration gradients exist in the solution within the yam elements of the fabric, and the individual fibres in the yarn elements are shown to differ in their accessibilities to dye; the yarn cross–sections are ‘ring–dyed’. In spite of these complexities the major features of the overall mass–transfer process are well represented by a simple model based on the concept of an equivalent diffusional boundary resistance to mass transfer. The numerical values obtained for δ are comparable with the yarn dimensions, which reflects the ‘coalescence’ of the individual boundary layers to form a region within the yarn elements in which dye transport by convective diffusion in the liquid phase limits the overall mass–transfer rates.     

Exhaust dyeing of meta-aramid yarn at low temperature and time

Exhaust dyeing of aramid fibre is difficult due to its high crystalline and compact structure. In this study aramid yarn is pre-treated with solvent dimethyl sulphoxide to facilitate the dyeing process and then dyeing is achieved with a cationic dye. Pre-treatment at high temperature leads to the reduction in tensile strength of yarn which is not desirable. Therefore, in this work pre-treatment has been carried out at different temperatures and time to standardise those parameters to enhance the dye uptake with minimum reduction in strength. Further, dyeing temperature and time has been standardised keeping the standard pre-treatment parameters fixed. From the study, pre-treatment temperature of 30°C for 10 min and dyeing temperature of 100°C for 30 min are found suitable for better colour strength without much compromising on strength of yarn. The fastness properties of untreated and treated dyed yarns were comparable.     

Dyeing behaviour of polyester heat-set at different temperatures: separate and competitive dyeings

Woven polyester upholstery fabrics, comprising multilobal filament yarn warp and textured yarn weft, were heat-set at different temperatures. The weft of these heat-set fabrics was dyed at high temperature (130 °C) using dyes of small and large molecular size, respectively, using both separate and competitive dyeing methods. The results show that the difference in dye uptake between substrates heat-set at immediately adjacent temperatures is higher in competitive dyeings than in separate dyeings. It has also been observed that dye uptake differences are always higher for dyes of large molecular size than for dyes of smaller size.     

The Beam Dyeing of Cotton Yarns

Presented at a Symposium on ‘Processing Textiles on Perforated Beams in the Dyehouse’ held by the Manchester Region at the Manchester College of Science and Technology, on 26th March 1965, Mr F. V. Davis in the chair Practical aspects of the beam dyeing of cotton yarn are described. Particular attention is given to methods and machines for preparing the dyer's beam, as well as to beam–dyeing plant and the different types of circulating pump. The application of vat dyes is discussed with special reference to high–temperature dyeing, and problems associated with azoic dyeings are outlined.     

Developments in Package Dyeing

Progress in package-dyeing yarn during the past ten years has been rapid, both in the total weight of yarn dyed, the types of fibre being dyed, and particularly in the design of dyeing machines and to a lesser extent in dyeing techniques. Polyester filament yarn is of great importance, but there have been significant developments in dyeing high-bulk acrylic yarns. In machinery developments, the outstanding features are in the rate of flow of liquor, and the frequency with which the liquor is circulated. New techniques have been developed to take advantage of these mechanical features, so that dyeing can be commenced at 135°C and the liquor dropped at this temperature, thus minimizing oligomer problems with polyester yarn. Many new disperse dyes of high sublimination fastness on polyester fibre have been introduced and these take full advantage of the new machinery and dyeing techniques. Another factor leading to wider use of package dyeing has been the need for shorter manufacturing cycles in the production of coloured yarn, particularly for woven fabrics. Worsted yarn, which would normally have been spun from dyed top is now being package dyed on a large scale. With spun yarns, the advantages of dyeing acrylic yarn in muff form have led to the rapid growth of this method of dyeing.     

Compatibility of dyes

Normally a combination of several dyestuffs is necessary to obtain a given colour. The behaviour of dyes in admixture is therefore of great practical interest. Level and repeatable dyeings are achieved more easily if dyes of almost equal behaviour in admixture can be selected. Most fundamental work on dyeing deals with up-take of single dyestuffs. Papers on dye-uptake in combination dyeings are comparatively rare. The early literature has been reviewed by Vickerstaff [1] and Peters [2]. At the end of the 60s compatibility values for cationic dyes were introduced [3, 4] and since then they have been used in practice as a criterion for dye selection. Meanwhile several dyelfibre classes have been investigated [5] and similar behaviour in admixture is recognized to be an important requirement of optimised dye ranges. In this article, papers on compatibility of dyestuffs for uniformly dyeable fibres will be reviewed. Coverage of fibre differences or on-tone dyeing of fibre blends is not included.     

硅氧烷低聚物的合成及其在泡沫染色中的应用

为了通过泡沫染色和光固化改善棉织物的染色性能，合成了一种含有不饱和双键的硅氧烷低聚物，设计了合适的含有聚合型黄色蒽醌染料、硅氧烷低聚物、光引发剂2,4,6-三甲基苯甲酰基-二苯基氧化膦（TPO）、表面活性剂十二烷基硫酸钠（SDS）的泡沫体系对棉织物进行泡沫染色。采用1HNMR和GPC分析了硅氧烷低聚物的化学结构和相对分子质量分布，采用FTIR表征了硅氧烷低聚物和染色棉织物的化学结构，采用SEM观察染色棉织物的表面形态。探讨了硅氧烷低聚物用量、染料用量、SDS质量浓度、TPO用量对泡沫性能和染色性能的影响，分析了硅氧烷低聚物的固色机理。结果表明，染料质量浓度30 g/L、硅氧烷低聚物用量为染料质量的2倍、SDS质量浓度2.0 g/L、TPO用量为染料质量的5%、紫外光照时间5 min时，染色织物染色深度可达5.70，耐皂洗色牢度和干/湿摩擦色牢度均为4～5级，水接触角为110.1°，紫外防护系数>50。硅氧烷低聚物通过侧基上的不饱和双键发生自由基聚合和硅醇基偶合交联实现固色，并赋予织物良好的疏水性能和抗紫外线性能。     

The Dyeing and Finishing of Tricel for Fashion Knitwear

This paper deals with ‘fashion knitwear’ made from high-bulk Tricel, crimped Tricelon and Tricel knit-deknit yarns. In addition to a discussion of the dyeing and finishing of fabrics and garments, brief details are given of the methods of yarn production and yarn dyeing.     

Effect of the addition of a modifier in the supercritical dyeing of polyester

The aim of the work was to investigate the effect of an ethanol addition in the dyeing of a commercial polyethylene terephthalate yarn with supercritical carbon dioxide. The equilibrium uptake in the yarn and the partition coefficients of three azo dyes between the polymer and the fluid phases were experimentally measured under different working conditions and compared with the data obtained without any modifier. It was found that the presence of the modifier increases the dye concentration in the yarn and the solubility of the dye in the supercritical phase, allowing good dyeing results to be obtained under less severe working conditions. The partition coefficient data were also satisfactorily regressed with a semi‐empirical correlation, available in the literature for a different system and here adapted to the partition of a dye between a fibre and a supercritical bath.     

Economic considerations from the exhaust application of reactive dyes under ultra-low liquor ratio conditions*

This paper reports on the investigation of the application of reactive dyes at ultra-low liquor ratios. Various types of reactive dye were included in the study, and it was found that acceptable dyeing results could be obtained by reducing the liquor ratio from the conventional 10:1 to 5:1. The accompanying reduction in electrolyte additions could offer several commercial benefits in both fabric and yarn dyeing.     

Some Observations on the Relation between Dyeing Properties and Fibre Structure

The processes by which dye is transferred from the liquor to the fibre are discussed briefly. Dyes and fibres are complex in structure and most dyeing systems are multicomponent; thus any attempt to correlate the chemical structure of a fibre and the chemical structure of the dyes that are used to dye it will probably have limited success. A simplified classification of some dyeing systems is given. In general, dye-fibre systems may be divided into non-ionic and ionic systems, the latter being subdivided into ionic systems with like and those with unlike charges. These systems are discussed. Structural features of the fibre that may influence the equilibrium sorption of dye are given and the effects of fibre structure on the kinetics of dyeing are considered. The dye-fibre system is analysed. There is no ‘theory of dyeing’ that can adequately describe practical behaviour.     

The development of a new continuous dyeing method based on an aerosol delivery system

A continuous method of dyeing polyester yarn has been developed in which yarn is forced into a moving plug within apparatus based on the Fibre-M texturing system. Dye is then applied in droplet form to the yarn plug. The method relies on the dispersion of low-molecular-weight disperse dyes in a solvent medium to provide a uniform application to the core of the plug. The demands of the textile industry require an extension of the method to a wider range of dye types in a water-based medium. This paper describes a feasibility study of an aerosol method of dye application to a yarn plug.     

莫代尔纤维活性染料染深色探讨

本文选用了不同类型的活性染料，在不同浓度下对莫代尔纤维进行染色，分析了它们染色特性值的差异，并对纤维结构及染色性能进行了探讨，从而选出了哪类染料更适合莫代尔纤维染色。     

Studies on dyeing method and dyeing properties of a sulphur black dye containing carboxylic acid groups on cotton

In this study the dyeing method of a sulphur black dye containing carboxylic acid groups on cotton was investigated. A dip–pad–bake dyeing process was applied and dyeing conditions were examined in detail. Thermal gravimetric analysis was used to determine both the baking temperature and the dehydrant selection. Fastness properties of the sulphur black dye containing carboxylic acid groups were tested. It is concluded that the sulphur black dye not only has good dyeing performance, but also possesses good fastness properties.     

Dyeing of nylon 6 fabric with a bifunctional sulphatoethylsulphone reactive disperse dye

A bifunctional reactive disperse dye containing two temporarily anionic sulphatoethylsulphone groups was synthesised and applied to nylon 6 fabric by exhaust dyeing at a variety of pH levels and temperatures. A monofunctional reactive disperse dye containing one temporarily anionic sulphatoethylsulphone group was also synthesised, and its dyeing behaviour was compared with the bifunctional dye. The bifunctional reactive disperse dye exhibited high exhaustion and total fixation yield under alkaline conditions. The results also indicate that the introduction of two temporarily anionic sulphatoethylsulphone groups of the bifunctional dye gave an enhancement in dyeing performance compared with that of the monofunctional dye. The dyes also showed very good levelling and fastness properties on nylon 6 fabric.     

Modification of the fine structure of heat-set polyester on dyeing at high temperature

Polyester woven fabrics for upholstery comprising multilobal filament yarn warp and textured yarn weft have been heat-set at different temperatures and then dyed at high temperature (130 °C) using dyes of small and large molecular size, in order to study the influence of dyeing on the fine structure of the fibre. The heat-set substrates have also been blind dyed under the same conditions for comparison. The modification of the fine structure and the influence of the dye and its molecular size have been evaluated by density/crystallinity, differential solubility and iodine sorption measurement. The results show that the thermal treatment associated with dyeing at 130 °C decreases the differential solubility and the iodine sorption of heat-set polyester. This is the result of a more compact fine structure and in consequence a degree of supplementary setting in the fabric. This effect is more pronounced in fabrics heat-set at relatively low temperatures.     

Dyeing of nylon 6 fabric with a new bifunctional vinyl sulphone reactive disperse dye

A new bifunctional reactive disperse dye containing a temporarily anionic sulphatoethylsulphone and a nonionic disulphide bis(ethylsulphone) groups was synthesised and applied to nylon 6 fabric by the exhaust dyeing at a variety of pH and temperature conditions. A monofunctional reactive disperse dye containing only nonionic disulphide bis(ethylsulphone) group was also synthesised and its dyeing behaviour was compared with the bifunctional dye. The bifunctional reactive disperse dye exhibited high exhaustion and fixation values at pH 6 and 120 °C. The results also indicate that the combination of temporarily anionic and nonionic reactive groups of the bifunctional dye provided great enhancement in dyeing performance compared to that of the monofunctional dye. The dyes also showed very good levelling and fastness properties on nylon 6 fabric.     

聚乳酸纤维的常压染色研究

在常压下,用七种分散染料及其复配染料对聚乳酸纤维进行染色,并对染色纤维进行了牢度性能测试。除了黄棕色外,其余染料的上染率都随着色度的增加而下降。同一只染料在同一的色度下,延长染色时间对增加染料的上染率作用不明显。随着染色温度的升高,黄素色和蓝色染料的上染率得到明显的提高,而对深红色和黄棕色染料而言这种作用并不明显。同时,通过测量染色纤维的色彩强度定量的描述了染料上染率对温度的敏感性。     

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。     

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.