Showing papers by "Imperial Chemical Industries published in 2008"

The Reactions of Cold-dyeing Procion Dyes with Cellulose

Abstract: The historical development of reactive dyes for cellulose and wool is reviewed briefly. The reactions of dichloro-s-triazinyl dyes with water, cellulose-model compounds and with the primary and secondary hydroxyl groups of cellulose are discussed and a scheme for describing the fixation of these dyes under mild and severe conditions of alkalinity and temperature is presented. Paper chromatography, colour reactions in presence of a pyridine—caustic soda mixture, and cuprammonium solubility have helped to provide the evidence on which this scheme is based.

The Heat Setting of Terylene Polyester Filament Fabrics in Relation to Dyeing and Finishing

Abstract: The dry heat setting of Terylene filament fabrics is considered in relation to dimensiond Stability, wet creasing, stiffness and recovery from dry creasing, and dyeing properties. The effects of aqueous heat are also discussed. Setting machines are described, and the setting conditions for Terylene fabrics outlincd.

Directed aerosol writing of ordered silica nanostructures on arbitrary surfaces with self-assembling inks.

Abstract: This paper reports the fabrication of micro- and macropatterns of ordered mesostructured silica on arbitrary flat and curved surfaces using a facile robot-directed aerosol printing process. Starting with a homogenous solution of soluble silica, ethanol, water, and surfactant as a self-assembling ink, a columnated stream of aerosol droplets is directed to the substrate surface. For deposition at room temperature droplet coalescence on the substrates and attendant solvent evaporation result in continuous, highly ordered mesophases. The pattern profiles are varied by changing any number of printing parameters such as material deposition rate, printing speed, and aerosol-head temperature. Increasing the aerosol temperature results in a decrease of the mesostructure ordering, since faster solvent evaporation and enhanced silica condensation at higher temperatures kinetically impede the molecular assembly process. This facile technique provides powerful control of the printed materials at both the nanoscale and microscale through chemical self-assembly and robotic engineering, respectively.

Tailored thermal expansivity in particulate composites for thermal stress management

Abstract: Only few composites with tailored thermal expansivity exist, even fewer with negative thermal expansivity fillers, and none are well characterised. Zirconium tungstate has an isotropic negative coefficient of thermal expansivity, and the overall coefficient of thermal expansivity (CTE) of a range of zirconium tungstate/epoxy composites was measured in order to examine the effects of volume fraction and particle surface treatment on the overall expansivity of the composite. This provides an imrpoved understanding of how particulate composites, with negative CTE fillers behave on heating. The thermal expansivity of the composites containing negative thermal expansivity (NTE) fillers is shown to agree with a simple volume fraction model.

Foam Dyeing and Printing of Carpets

Abstract: This paper was presented to the West Riding Region on 9 October 1980, and to the Huddersfieid Region on 3 February 1981. Foam application of dyes by printing or continuous methods offers potential savings in materials and energy, faster production and the possibility of ‘no wash–off processes. Factors affecting the composition and mechanical conditions required to produce stable foams have been examined in the laboratory and these foams have been applied to nylon carpets by rotary screen, horizontal pad, doctor roller and slots. Rates of fixation in steam of some acid dyes on nylon appear to be significantly faster using the foam application (ca. 50% pick–up) method compared with conventional methods (300–400% pick–up).

Detoxification of cyanide by immobilised fungi

Abstract: Cyanide detoxification was studied by immobilisation of fungal mycelia that had been induced to form cyanide hydratase (formamide hydrolyase) which is able to hydrolyse cyanide to formamide. The fungal pathogens of cyanogenic plants, Stemphylium loti, Gloeocercospora sorghi and Fusarium moniliforme were immobilised using polyelectrolyte flocculating agents. The effect of immobilisation on the enzymic properties of S. loti and G. sorghi were investigated. The apparent Km values increased from 21.0 mmol and 25.5 mmol KCN to 43.5 mmol and 71.0 mmol KCN, respectively. The pH profile for the two enzymes widened on immobilisation. The stoichiometry of 1:1 cyanide utilisation to formamide formation was retained on immobilisation, with complete conversion of 70 mmol KCN in 120 min by 0.12 g dry wt of S. loti and in 6 min by 0.13 g dry wt of G. sorghi. When the two fungi were stabilised by immobilisation, and tested in column reactors containing 1.2 g dry wt of S. loti and 1.3 g dry wt of G. sorghi, they completely converted cyanide (70 mmol; added continuously at 7.5 ml h−1) into formamide for 2 days and 30 days, respectively. Stability was enhanced by inclusion of 1.0 mmol glucose in the 70 mmol KCN solution, by a further 10 h for S. loti and an extra 10 days for G. sorghi. Operational stabilities of immobilised G. sorghi (1.3 g dry wt) and F. moniliforme (1.0 g wet wt) in column reactors, with 100 % cyanide conversion, at varying flow rates was investigated. G. sorghi was stable for 15, 10 and 2 days whereas F. moniliforme was only stable for 48, 20 and 10 h at 30, 60 and 120 ml h−1 flow rates respectively.

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

Abstract: 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.

The Role of Auxiliary Products in the High–temperature Dyeing of Polyester

Abstract: The effect of a number of auxiliary products of both the carrier and the non–carrier type on the levelling of disperse dyes under high–temperature (HT) conditions has been determined for a range of 12 dyes. The most effective products are carriers based on butyl benzoate, trichlorobenzene, diphenyl and benzyl benzoate. The effectiveness of a particular chemical type depends on its emulsification under dyebath conditions. Non–carrier agents show less improvement in levelling than all but the most ineffective carriers. Non–ionic agents can retard and restrain dyes, and can also adversely affect the dispersion stability of dyes.

Modification of a novel protein product

Abstract: The production of single cell protein (SCP) on an industrial scale has now been established using the ICI ‘Pruteen’ process. An economic process for the reduction of nucleic acid in the product has been developed: potentially it could be used to produce a protein concentrate suitable for human consumption. Controlled enzymic hydrolysis of this concentrate yields a range of protein products with improved functional properties.

Education in a Changing Society

Abstract: The discussion falls into two parts. The first is designed to show the progression ofthe Society's interest and involvement in education. The second displays some recent comparisons of educational processes, particularly in science and technology, in the U.S.S.R., U.K., and U.S.A.

The Life and Times of Peter Griess

Abstract: Until he was 28 years old Peter Griess betrayed no sign of his latent genius for chemical research. As a student at Marburg University, he at first showed little interest in science and preferred the society of irresponsible and pleasure-seeking companions. His discovery of diazo compounds in 1858 attracted the attention of others and led him to write the first of more than 140 contributions to chemical literature. Almost the whole of his work on diazo compounds and their reactions, and on azo dyes, was carried out in England, first at the Royal College of Chemistry and thereafter during his 25 years as chemist to Samuel Allsopp & Sons at Burton-on-Trent. Griess's work is sketched against the background of the times. He is seen as a nostalgic, lone worker, watching the growth of a great industry in which he had no part but which developed by organised research based on his own pioneering offorts. Honoured in this country and abroad during his lifetime, Griess died suddenly in 1888.

Defective Colour Vision. I–Its Nature

Abstract: The various types of defective colour vision are described with particular reference to the sensations experienced. Two theories of colour vision, the trichromatic and opponent–colours theories, are described briefly and the recent objective proof of both is reviewed.

Particle–size Determination with the Disc Centrifuge

Abstract: The provision ofstable dispersions with desirable technical properties involves the dye manufacturer in careful control of production. The disc centrifuge, with direct removal of the sample from the liquid interface, has been found valuable for this purpose. Several aspects of its operation and accuracy in the analysis of dye and pigment dispersions are discussed.

A Historical Approach to the Dyestuffs Industry

Abstract: Organised for a world economy, rich in natural resources, and with a traditionally liberal and moral outlook, nineteenth century Britain was singularly well qualified to be the birthplace of the synthetic-dye industry. Yet, in the case of the organic chemical industry, the social and economic conditions that were often so favourable to the innovation and growth of industrial and commercial enterprises were not those best suited to combat the paternalism and planned economies of the aspiring new Germany. Thinking in terms of large-scale production of relatively cheap materials, British industrialists built up highly profitable industries based on the production and export of coal-tar and its distillation products. Without imagination, intellectual foresight, and stimulus from other industries, the British chemical industry stood aside whilst other nations developed their own dye-making enterprises. A European war and a renewal of belief in a modicum of State intervention were turning points marking a new determination on the part of Great Britain to be no longer subservient to foreign domination in the field of organic chemicals.

The Spacing of the Higher ISO Light-fastness Standards

Abstract: Strips of the ISO Master Light-fastness Standards 5–8 were exposed to daylight for five different periods and the amounts of fading assessed visually against a Grey Scale and determined colorimetrically. Standard 6 was found to be 1·6 times as fast as Standard 5, and Standard 7 4·2 times as fast as Standard 6. The significance of these ratios is discussed.

Fast Dyeings on Wool-Cellulosic Unions

Abstract: Meetings of the Scottish Section held at the St, Enoch Hotel, Glasgow, on 9th December 1958, Mr. W. G. B. Grant in the chair; of the West Riding Section held at the Victoria Hotel, Bradford, on 26th February 1959, Mr. R. Heaton in the chuir; and of the Huddersjield Section held at Silvio's Cafe Hudders field, on 17th March 1959, Mr. H. Boothroyd in the chair In recent years, increased interest in wool-cellulose unions has, in some cases, called upon the dyer to produce the same standards of fastness as ran be obtained on the separate fibres. It has been found that, by rareful selection of dyes and dyeing methods, it is possible to apply reactive, onium, vat, and azoic dyes satisfactorily to wool—cellulose unions without causing significant fibre damage.

Analytical Appraisement in the Manufacture of Dyes

Abstract: The advantages of having methods for evaluating the performance of chemical reactions in the manufacture of dyes are discussed, and the use of analytical techniques as an integral part of process investigation is exemplified. In a survey of the application of chromatographic, spectrophotometric and other techniques to the various types of problem that can arise with anthraquinone derivatives, examples are given relating to the production of acid, disperse and vat dyes.

The Accuracy of Colorimetric Instruments in Dye Strength Determinations

Abstract: A statistical examination is described of the results of a series of dye strength determinations with typical colorimetric instruments, made by six observers, each using five acid dyes which substantially covered the visible spectrum and which were employed in four strengths of solution. Of the instruments examined, the photoelectric absorptiometer is the most accurate, with an overall mean standard error of 1·00%, compared with 1·35% for the visual spectrophotometer and 2·49% for a Duboseq-type colorimeter. This last instrument gives the least consistent results, ranging from a mean standard error of 0·85% for a blue dye to one of 5·47% for a yellow. The accuracy of the results given by the photoelectric absorptiometer is independent of the colour-matching experience of the operator, whereas that of the other two instruments is dependant on such experience.

The Production of Fast Shades on Knitted Cotton Fabrics, Nets and Lace*

Abstract: Summary Methods of dyeing vat and Soledon dyes on knitted cotton fabrics, nets and lace on the winch machine are described. Means of overcoming frothing and oxidation difficulties with vat dyes are suggested, and a general method for dyeing a selection of the faster-to-light Soledon dyes without removal from the winch, based on washing between dyeing and developing, is described.

Aspects of Pigment Dispersion related to Usage

Abstract: Optical and fastness properties are of limited value unless satisfactory dispersion of a pigment can be achieved and maintained. In aqueous systems dispersion and stabilisation can be effected by soluble surface-active agents, but in non-aqueous media the degree of stabilisation is much lower. Dispersion of pigments into viscose solution is best achieved by minimising differences existing at the mixing boundary. In pigment printing compositions fineness of particles affects both fabric penetration and pigment binding. Stabilisation of yellow organic pigments with non-ionic agents is necessary to avoid coagulation of emulsion paints. In non-aqueous systems mixing procedures are most efficient when conditions allow maximum contribution by the pigment to its own dispersion. The degree of particle flocculation existing in a printing ink is a controlling factor in its behaviour on the paper surface. Seeding arising from milling high-pigment–low-resin paint compositions can be reduced by lowering the differential resin concentration at the dilution boundary. Variations in depth of colour caused by differences in film-forming conditions for paints containing phthalocyanine blue are substantially overcome by surface treatment to reduce flocculation.

A comprehensive population balance model of emulsion polymerisation for PSD & MWD: Comparison to experimental data

Abstract: A population balance model for emulsion polymerisation has been developed. This model captures PSD and MWD, both of which are key performance indicators for the end latex product. The model employs purely mechanistic kernels and is aimed at maximising predictive capacity. The model is validated against a multi-objective experimental target. The aim is to predict data for PSD, solids, particle number as well as global molecular weight. The experimental system investigated is a vinyl acetate/butyl acrylate copolymerisation with ionic emulsifier and thermal initiator. The predictive capacity is tested by tuning the model to one set of experimental data, then trying to predict results from a further perturbed experiment, with no further tuning. The results of this study indicate that the model is able to capture the main process trends as well as providing an accurate representation of quantitative data.

Proceedings of the Society Finishing of Fabrics containing Terylene Polyester Staple Fibre

Abstract: This paper describes some of the differences between the properties of Terylene polyester fibre and wool, discusses how these differences manifest themselves in finishing, and outlines the response to finishing treatments of fabrics containing Terylene staple fibre, both by itself and blended with botany wool.

Colour display and related methods

Abstract: A display comprising at least two cavity structures substantially juxtaposed, the interiors of the cavity structures being respectively coloured, at least in part, with a test colour and a reference colour, wherein the test colour is related to the reference colour in that it has a substantially similar or the same hue characteristic, but a different lightness characteristic.