Determination of the Viscosity in Cadoxen Solvent of Cellulosic Materials Dyed with Reactive Dyes

A modified cadoxen solvent was used to determine the viscosity of reactive-dyed cellulosic materials. The conditions for completely dissolving cellulosic materials dyed with different types of reactive dyes were standardised. Reactive-dyed cotton materials showedno anomalous viscosity behaviour in the cadoxen solvent. With viscose rayon samples dyed with bifunctional reactive dyes, higher viscosity values were observed when measurements were carried out immediately after dissolution. However, on storing the solutions for a further 24 h, the viscosity values became independent of the type or the amount of dye andwere identical with those of undyed rayon. Thus, measurements of the viscosity of reactive-dyed materials can be conveniently carried out in cadoxen solvent.     

Photoreactivity of Wool Dyed with Reactive Dyes

Presented at the 13th Congress of the International Federation of Associations of Textile Chemists and Colourists in London on 20 September 1984. Processes induced by two kinds of illumination (ultra-violet and Xenotest) in wool dyed with reactive dyes ha ve been investigated as a function of time. The fading of dyed fibres has been determined in terms of the conditions of illumination. The degradation of wool was followed on the basis of changes in alkali solubility and tensile characteristics. Moreo ver the colour change of the dyed fibres was also determined. Correlation was found between the chemical structure of the dye, the extent of fading and the photodegradation undergone by the wool. On the basis of amino acid analysis conclusions were drawn on the photodegradation mechanism of wool, both uncoloured and dyed with reactive dyes. Reactive dyes protect wool against photodegradation, and at the same time the light fastness of reactive dyes on wool is 1–1.5 units higher than on cotton, both under ultra-violet (u.v.) and Xenotest irradiation.     

Identification of Newer Types of Reactive Dyes on Cellulosic Fibres – IV

The reactive systems and chromogens present in further types of reactive dye are briefly discussed. Dyeings, or prints, on cotton of selected dyes in each range, including more black reactive dyes, have been tested to distinguish between the various types of reactive dye. Special attention is paid to methods of detecting the presence of metals in reactive dyeings.     

Identification of Newer Types of Reactive Dyes on Cellulosic Fibres – II

The reactive systems and chromogens present in further types of reactive dyes are briefly discussed. The results are described of tests on dyeings (or prints) of selected reactive dyes on cotton, carried out to distinguish between the various chemical classes and to place them in their apparent position in Clayton's Tables. Particular attention is paid to the black reactive dyes, and a scheme is proposed for differentiating between dyeings of 25 different black reactive dyes on cotton.     

Apparent Colour Yield in Dyed Textiles

Various factors influence the visual efficiency of a fixed amount of colorant in a textile. The relevant optical phenomena are reviewed and treated in non-mathematical outline. The results of calculations on a number of simple optical models give rational bases for considering the qualitative effect on colour yield of the factors: fibre size and cross-section; incomplete penetration of colorant into the textile structure; colour-blended textiles; packing density of yarns and fabrics; polarization and fibre orientation; internal scattering and matt fibres; mechanical and added finishes; raised and pile structures; and ring-dyed fibres.     

Reactive Dyes in the Coloration of Cellulosic Materials

The development of reactive dyes for cellulosic fibres is considered, together with their organic and physical chemistry. The relation between the theoretical aspects of the chemistry of reactive dyes and their application and development problems is discussed.     

The Behaviour of Selected High Wet Modulus Viscose Fibres Dyed with Direct Dyes

Four high wet modulus viscose fibres (Avril, Avril III, Prima, and Viloft) were evaluated for dye exhaustion characteristics using cotton and standard viscose fibres as standards. Dyebath exhaustion was quantified by spectrophotometry analysis. Viscose fibres, as a class, exhibited higher percentage exhaustion for all dyes studied than did the cotton fibres. Dye uptake by the viscose fibres varied, highlighting the need for further research to enable the effect of differing dye classes or differing control fibres to be studied. Viscose fibres may vary in dyeability from one producer to another due to differences in fibre cross-section, skin-to-core ratio, molecular orientation or pore size.     

纤维素纤维用C.I.活性红195的染色性能研究

本文研究了C.I.ReactiveRed195(活性红M-3BE)在6种纤维素纤维棉麻粘胶竹纤Lyocell以及Modal纤维上的染色性能及其之间的差异,探讨了工艺因素变化(碱剂中性盐温度)对活性染料染色性能的影响,并总结出一个较优的纤维素纤维用活性染料染色的工艺。     

Application of Ozone in Stripping of Cotton Fabric Dyed with Reactive Dyes

ABSTRACT

This paper discusses the color stripping of cotton fabric dyed with four reactive dyes using ozone. An ozone color stripping process has been optimized in terms of pH, ozone dose, treatment time and dye concentration. Color stripping efficiency of the process is evaluated in light of the color properties including Lightness (L*), Lightness Difference (?L*), and Color Difference (?E*) in addition to strength properties, i.e., copper number and degree of polymerization as well as compared with a control method (conventional reductive color stripping method). The results demonstrate maximum color stripping at an ozone dose of 10 g/h, exposure time of 45 min, and pH maintained at 5. The Stripping Efficiency, however, decreases with increasing dye concentration from 0.5% to 4%, which implies that decolorization of dyed fabric with higher initial dye concentration requires higher ozone dose and/or longer exposure time. The strength of the ozone-stripped fabric sample is almost similar to that of control. The chemical oxygen demand of effluent generated by ozone stripping process is 97% lower than the effluent produced by the conventional stripping method. The Ozone Stripping Process hence proves to be environment-friendly as it consumes less water, energy, and chemicals.     

Padding,Drying, Steaming and Baking Stages in the Application of Dyes to Cellulosic Fibres and their Blends with Polyester Fibres

Padding, drying, steaming and baking are the basic unit processes of continuous dyeing; special aspects of this very wide range of processes have been examined. A new technique of padding has been developed in which the air in the material is removed by applying a high vacuum. The material is then immersed in the treating liquor without release of the vacuum; impregnation occurs on release of the vacuum. This technique can also be used in batchwise dyeing. Its advantages are that penetration is greatly improved and excellent results are obtained on completely unprepared material without the need to use wetting agents; in batchwise dyeing the uniformity of dye absorption during the initial stages of dyeing is improved. In this padding system, the pressure of the atmosphere forces the liquor into every interstice of the material, in contrast to the situation in conventional padding, where the trapped air opposes the pressure of the pad mangle. Results of the application of this technique are illustrated and discussed. Drying, steaming and baking have been considered as heat- and mass-transfer unit operations, and the techniques and data of chemical engineering have been applied to show that this approach can give much useful information to the dyer without the need for difficult empirical experimentation. There are, however, few data derived on a textile basis; even so, the standard data available show reasonable agreement with textile experience. More data in this field are required. Thoughtful use of such studies could lead to improved textile processing machinery. Finally, the ICI high-temperature (HT) steaming process (with superheated steam) and continuous pressure steaming are compared with comparable conventional treatments. The advantages and limitations of these systems are discussed. The two new methods are shown to be complementary, but the HT steaming process is more versatile in application and simpler in design.     

反应性固色剂D-20在棉染色中的固色性能研究

本文研究了反应性固色剂D-20在活性染料染色织物上的固色性能,这类聚合物材料是在具有反应性基团的高聚物树脂中引入十八碳的长碳链侧链端基,将长碳链化合物与丙烯类单体共聚形成的结果表明:含长碳链结构的聚合物材料D-20在纯棉织物上的成膜性能固色性能和手感都有明显的改善不仅能明显提高活性染料染色织物的湿处理牢度,而且能提高固色后织物柔软性能。     

活性染料染色物变褪色和落色的原因分析

活性染料染色物的变褪色和落色是当今活性染料存在的主要问题之一.该文分析了产生这种问题的原因以及活性染料受影响的部位.     

Anomalous Fluidity of Cellulose Dyed with Certain Reactive Dyes and its Significance to the Practical Dyer*

The apparent chemical damage caused to cellulose by dyeing with reactive dyes, as assessed by determining the fluidity of the material in cuprammonium hydroxide, was examined. High values of fluidity were obtained, although tensile-strength tests show that this parameter is not adversely affected by these dyes. The possible causes of these high values are discussed. The influence of pH on fluidity values and colour is also discussed. Significant variations in colour are encountered when the pH is not carefully controlled.     

Latest Developments in the Batchwise Application of Hot-dyeing Reactive Dyes to Cellulosic Knitwear

A dyeing profile for a range of reactive dyes suitable for application to cellulosic knitwear is defined. Such a profile shows good level-dyeing, reproducibility and fastness properties together with potential for simplified dyeing processes.     

分散染料染色物若干色牢度问题分析和改进技术

近年涤纶染色物的变褪色和落色等色牢度问题以及色点、色斑等是分散染料存在的主要问题之一,本文分析了产生这些问题的原因与改进技术.     

HN-型高固色率活性染料的低盐染色法

HN-型高固色率活性染料红HN-2B、金黄HN-R、深蓝HN-2G,其吸色率在95％以上,固色率在85％左右。以几种不同的染色方法,用HN-型高固色率活性染料对棉纱及棉布进行了染色,染色结果表明,在中温下,该活性染料可以采用低盐染色。当盐的加入量减少为30g/L是标准加入量的1/2）,其最适宜的染色条件为:浴比1∶20,染色深度3％,40℃上染,60℃固色,氯化钾20g/L和柠檬酸三钠为10g/L,碱磷酸三钠的加入量为4+10g/L时,其K/S值下降百分数:红HN-2B为10.16;金黄HN-R为5.57;深蓝HN-2G为8.57。     

活性染料染色物若干色牢度问题分析和改进技术

活性染料染色物的色牢度如光牢度、汗-日光牢度、湿摩擦牢度和耐氯牢度等问题是当今活性染料存在的主要问题之一.本文分析了产生这种问题的原因以及活性料受影响的部位,并提出了改进的技术.     

活性染料染色物若干色牢度问题分析和改进技术

活性染料染色物的色牢度如光牢度、汗-日光牢度、湿摩擦牢度和耐氯牢度等问题是当今活性染料存在的主要问题之一。本文分析了产生这种问题的原因以及活性料受影响的部位,并提出了改进的技术。     

Bonding of Sequestering Groups to Cellulosic Fibres.

The stability of PAR-s-triazine* covalently attached to cellulose has been studied under alkaline and acidic conditions. Results indicate that the rate of hydrolysis is slower in alkaline than in acidic media. This difference is explained in terms of ketone formation via dissipation of residual chlorine in the s-triazinyl ring. In the case of alkaline hydrolysis it is proposed that the observed two-phase mechanism depends on structurally different PAR-s-triazine entities, whereas the glycosidically-bonded s-triazine moieties seem to be responsible for the rapid hydrolysis under acidic conditions. Finally, the stabilizing effect of the substitution of remaining chlorines in PAR-s-triazine with various nucleophiles is demonstrated.