Objective This 36-monthly period mainly consisted in looking for suitable formulations for wool and cotton dyeing in supercritical carbon dioxide medium, and adapt them to a larger scale device.Solubility studies were performed to find suitable dyestuffs. Conventionally used hydrophilic dyestuffs for natural fibres are not suitable for dyeing from SCO2 because of their low solubility in SCO2. However, it was found out that hydrophobic, non-ionic dyestuffs of low molecular size are required to dye natural fibres from supercritical CO2. The highest solubility in this solvent was found for dyes with short alkyl groups. Higher-sized dyestuffs molecules were not or only slightly soluble. The presence of reactive groups in the colouring molecules is helpful to achieve high wet fastness of dyed samples. Besides, the solubility or dispersion of dyestuffs in supercritical CO2 can be achieved by addition of small amounts of modifiers or surfactants.The routes to settle efficient dyeing recipes in SCO2 medium may be distributed among three alternatives that are the treatment of the textile substrate, the alteration of the dye molecule, and the modification of the supercritical fluid properties. In the first case, a modification of the fibre might improve its dyeability properties, either through a physical treatment of the textile surface, or by a chemical introduction of specific functional groups into the fibre chains. The second possibility that is worth investigating is the modification of the dyestuff with other chromophores or substituents that may lead to new fixation mechanisms and/or new application procedures for better binding properties to the fibres. Finally, the solvent power of the supercritical fluid may be enhanced through a combination with one or several modifiers, and tuned up by pressure, temperature and flowrate, so as to improve dye solubility and level up dye penetration into the fibres. A good coloration with high levelness was achieved for fibres dyed from supercritical CO2 with selected dyestuffs. The coloration can be enhanced by applying high temperatures (T > 80°C for cotton or 100°C for wool), high CO2 densities, high pressures (p > 250 bar), increasing the time and by addition of a modifier. Applying a fabric pre-treatment or using a fluoro-surfactant may also bring enhancements for cotton dyeing.Water and methanol are the best modifiers with the restriction that the presence of even small amounts of water at high temperatures (T > 100°C) causes a decrease of the quality of wool.The whole colour gamut is covered by the studied dyestuffs. Several commercially available dyestuffs were found to be suitable for dyeing cotton and wool from SCO2, like disperse, solvent, disperse reactive and natural dyestuffs. Furthermore, modification of commercially available disperse or solvent dyes into reactive derivatives, and formation of a complex with mordanting agents are two approaches to improve the insufficient fastness properties of conventional disperse dyes.From the data obtained from laboratory- or pilot-scale SCO2 dyeing experiments and their comparison with the conventional process, it has been proved that the dry route with supercritical carbon dioxide might be viable, once the right dyestuffs are available.Scientific and technical objectives: Possible industrial applications of supercritical fluids technology, which industrial valorisation has already been made in food industry, has been investigated in different sectors considering the huge advantages by comparison with traditional techniques using solvents. In textile area, research has been done for dyeing of synthetic fibers with disperse dyes, in supercritical carbon dioxyde (SC02), leading to a process avoiding water and effluents. The objectives of the project are to extend the applications of this new technology to natural fibers and blends, using this "supersolvent" not only as a carrier but also as a reaction medium, e.g. for dyeing process with vat or reactive dyes for cellulosics and milling or reactive dyestuffs for wool. Industrial objectives: The research involved in this project will allow to develop SC02 technology within a short delay, giving some economical advantages contributing to a higher competitiveness for European textile industry against far and medium east countries. As soon as the flexibility of the process has been proved by several applications in textile industry, e.g. polyvalency for dyeing different nature of fibers with different types of colourings, the industrialization could occur quickly, considering that existing equipments used in food industry will need only simple adaptations for the transfer to textile (especially reactor configuration). Industrialisation is already possible for polyester dyeing with disperse dyes. However the success of such a new technology will depend especially to it's multi use possibilities, e.g. dyeing both natural and synthetic fibers, involving commercial available dyes. More, the targeted market involving natural fibers is much more important: natural fibers and mixtures represents a market share of more than 60 %. Wearing industry: 53% cotton, 9% wool Worldwide market shares (1994): cotton 45,6%; wool 3,7%; man made fibres: 50,7% (including technical textiles); PES/wool 9%. Europe: wool: 10 to 12 %; cotton > 25 %. Approach: The use of vat dyes or reactive dyes for cotton and wool dyeing will necessit a basic research using technical informations available on chemical reactions in SC02. Lab scale experiments will be performed by Research Organisations as to define the process requirements and thus those of industrial equipment. This work will be performed together with an equipment manufacturer (providing SC02 industrial equipment for food industry) and technical informations and support from two textile dyes manufacturers. An economical, environmental and social assessment will be done by end users. Equipment and process requirements definition will allow to define the exploitation plans. Fields of science engineering and technologymaterials engineeringfibersengineering and technologymaterials engineeringcolorsengineering and technologymaterials engineeringsynthetic dyesengineering and technologymaterials engineeringtextilesnatural scienceschemical sciencesorganic chemistryalcohols Programme(s) FP4-BRITE/EURAM 3 - Specific research and technological development programme in the field of industrial and materials technologies, 1994-1998 Topic(s) 0101 - Incorporation of new technologies into production systems Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator INSTITUT FRANCAIS DU TEXTILE ET DE L'HABILLEMENT EU contribution No data Address Avenue Guy de Collongue 69134 ECULLY France See on map Total cost No data Participants (6) Sort alphabetically Sort by EU Contribution Expand all Collapse all AACHEN UNIVERSITY OF TECHNOLOGY Germany EU contribution No data Address 8,Veltmanplatz 8 52062 AACHEN See on map Total cost No data Celabor Belgium EU contribution No data Address 38,Avenue du Parc 4650 Chaineux See on map Total cost No data Chematur Ecoplanning Oy Finland EU contribution No data Address Karjaranta 28101 Pori See on map Total cost No data DYVERTEX SPRL Belgium EU contribution No data Address Rue Victor Besmes 37 4800 LAMBERMONT See on map Total cost No data Dechamps Textil AG Germany EU contribution No data Address 215,Eilendorfer Strasse 52078 Aachen See on map Total cost No data Emanuel Lang Textiles France EU contribution No data Address 15,Rue Paul Lang 68560 Hirsingue See on map Total cost No data
