Society of Dyers and Colourists

Day-to-day problems in the dyehouse, resulting in the production of unacceptable goods, can often be overcome by the temporary correction of faults rather than by the eradication of their causes. A control strategy has been evolved at ICI over several years to tackle such circumstances. The areas affecting the pass/fail of dyed goods are first identified and target levels defined for each operation. From knowledge of the effect of errors on the operations, pass/fail rates are predicted for processes; firstly without control and then after incorporation of a control strategy. The use of this technique is demonstrated for improving the efficiency of dyeing polyester-cotton blends by continuous and semi-continuous routes

David Harris tells how the Corneal Laser Centre is helping people world wide gain normal colour vision

Debra K Hobson and David S Wales describe how the production of anthraquinone dyes can be environmentally sound

Reactive dyes for wool which incorporate a water-stable bisulphate-isocyanate adduct as the 'masked' reactive group can be applied in the form of levelling acid dyes. High fastness to washing on wool can subsequently be attained by fixing the dye with alkali or steam treatments

Condensation of 2-bromo-1,4-dihydroxyanthraquinone with alcohols and phenols affords the 2-ether derivatives, which colour synthetic-polymer fibres, particularly polyester, in yellow-orange hues of good build-up and light fastness. The influence of the 2-ether substituent on the colour of these 1,2,4-tri-donor-substituted anthraquinones is discussed, together with the relative influence of the electron acceptor 2-sulphone substituent

The synthesis of a series of 2-thioethers of 1,4-dihydroxyanthraquinone by various preparative routes is described. The colour, dyeing and fastness properties on synthetic-polymer fibres of these dyes is discussed in terms of the nature of the substituent in the thiol group. 2-(2-aminophenylthio)-1,4-dihydroxyanthraquinone, which gave the new heterocycle 6,13-dihydroxyanthra[2,3-b]benz[d]thiophen-7,12-dione on Pschorr intramolecular cyclisation, was observed to undergo cyclisation, during both its synthesis and its application to polyester fibres, to the blue coloured 7-hydroxy-14H-naphtho[2, 3-a]phenothiazine-8,13-dione

Chris Hawkyard, ex-chairman of Manchester Region, reports on the Region's Centenary Symposium. Paper discusses the development of cotton usage in the industry

A range of yellow fluorescent 2-pyrazoline acid dyes has been synthesized. Their spectral and dyeing properties (on wool and nylon) depend both on the nature of the substitution pattern of the dye and on the nature of the fibre substrate. Exhaustion and fastness to washing, which are better on nylon than on wool, are improved by substituents attached to the 2-pyrazoline ring. Fastness to light is independent of the fibre and is increased by substituents on the 4- and 5- positions of the 2-pyrazoline ring. The fastness properties of the pyrazoline dyes were compared with those of C.I. Acid Yellow 7

As Stan Ward explains, there is a long history of education in Manchester Region

SDC Enterprises Ltd, the trading company established by the Society of Dyers and Colourists to sell colour fastness testing products globally, has recently celebrated the first 25 years of continuous production of their market leading SDC Multifibre DW test fabric.

4-Hydroxy-1,8-naphthalimides and the isomer mixtures of 3- and 4-hydroxy-7H-benzimidazo-(2,1-a)-benz(d,e)-isoquinolin-7-ones were coupled with diazotised arylamines to yield orange-red to bluish-red dyes having good coloration properties and excellent fastness to light on polyester fibres. Structure-property relationships in the dyes are discussed with respect to the nature of the substituents in the imide, imidazole and arylazo moieties

Paper is a letter to the editor discussing the a non-standard blue wool standard in external exposure tests

In anticipation of the Single Market, the European Commission has agreed upon six wide-ranging directives as the framework for its health and safety policy. In the UK the Heath and Safety Commission has responded by introducing detailed proposed regulations intended to bring British practice into harmony with European legislation. Matthew Castle discusses the implications

Gert Grozinger draws parallels between the growth pf Manchester Region and dye discoveries. Also includes an article entitled 'Indigo: Historical Perspectives' by K McLaren

Review article giving an overview of the history of art from the perspective of the pigments used to create that art and the development and influence of science and technology in art. It is not intended to be an exhaustive review of every pigment ever used for the purpose, but aims to cover the most important and interesting colorants, and give the reader a taste of the long history of pigments

The available experimental data for small colour differences between surface colours under illuminant A have been analysed in a manner similar to that used earlier for the comparable results under daylight. Until now no formulae specifically designed for use with illuminant A data have been available. This paper describes the development of the BFDA (l:c) formula for illuminant A

Values for peroxide concentration, temperature and time of bleaching were established in accordance with a rotatable central plan of experiments for three variables. The materials used were (i) untreated wool, (ii) the same wool after it had been chlorinated in an acidic medium (the first part of the Hercosett process), and (iii) the same wool after it had received the full Hercosett treatment. The behaviour of the three different types of wool on bleaching with hydrogen peroxide has been compared through the response equations relating a given parameter to the bleaching conditions

To investigate the performance of the Pye-Unicam SP8-100 colour-measurement system, measurements made on several samples were compared with measurements made on a Kollmorgan KCS-18 abridged spectrophotometer

The colour differences computed using three advanced formulae have been compared for numerical standard/sample pairs located at regular intervals throughout the colour space. A ratio method was used to compare the values obtained, so that the regions of the colour space where the greatest disagreements occur could be identified. The level of disagreement between the BFD and the CIE94 formulae was generally lower than that between the CMC and CIE94 formulae. In the latter case, the greatest level of disagreement covered a large part of the colour space, concentrated especially in the orange region. It is recommended that studies of the performance of these formulae in relation to visual assessments are made, for real standard/sample pairs located in this region

This paper discusses the mode of action of wool-protecting agents covering topics such as the screening of formaldehyde donors, evaluation of DMEU in practice and the mode of action of DMEU

The relationship used previously for calculating time- temperature dyeing programs based on the condition of isoreactivity of the system has not been derived correctly, leading to increased consumption of thermal energy. A correct derivation is presented. In addition, a general solution is offered where the kinetics of dyeing are described by an arbitrary function, the rate constant being the known function of temperature. Also includes correspondence by J Cegarra, P Puente and J Valldeperas (JSDC, September 1979, p. 337)

A previously published method for the u.v. spectrophotometric determination of Eulan WA New (or Eulan U33) and Mitin FF High Conc used as mothproofing agents on wool is critically assessed. Evidence is presented which shows that this procedure is not sufficiently accurate for the determination of Eulan WA New (or Eulan U33) on wool. However, the u.v. spectrophotometric determination of Mitin FF High Conc shows no evidence of bias and may be suitable for the determination of this agent on wool. The preparation of blended wool tops for use as analytical standards is described