Browsing by Author "Okubayashi, Satoko"

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    Eco-Friendly Disperse Dyeing and Functional Finishing of Nylon 6 Using Supercritical Carbon Dioxide
    (MDPI AG, 2015-09) Okubayashi, Satoko; El-Taweel, Fathy; Ma, Jaehuyk; Abd El-Aziz, Eman; Abou Elmaaty, Tarek
    In this work, a supercritical carbon dioxide assembly was successfully constructed for dyeing Nylon6 fabric. Primary experiments were carried out to confirm the possibility of bringing the dyeing up to factory scale. A series of disperse azo dyes with potential antibacterial activity were applied to dye the fabric under our study in supercritical carbon dioxide (scCO(2)). The factors affecting the dyeing conditions (i.e., dye concentration, time, temperature and pressure) and functional properties were discussed and compared with those in aqueous dyeing. The comparison revealed that elimination of auxiliary chemicals such as salt, carrier or dispersing agent has no diverse effect on dyeing. The color strength of the dyed fabric evaluated by using K/S measurements increased by increasing dye concentration from 2% to 6% owf. (on weight of fabric). The nylon6 fabrics dyed in supercritical carbon dioxide have good fastness properties, and especially light fastness compared with conventional exhaustion dyeing. Antibacterial activity of the dyed samples under supercritical conditions was evaluated and the results showed excellent antibacterial efficiency.
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    Water free dyeing of polypropylene fabric under supercritical carbon dioxide and comparison with its aqueous analogue
    (ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS, 2018-09) Abou Elmaaty, Tarek; El-Taweel, Fathy; Elsisi, Hanan; Okubayashi, Satoko
    A facile one step method was developed for dyeing polypropylene fabrics with hydrazono propanenitrile disperse dyes under both aqueous and supercritical carbon dioxide mediums. The dyeing was carried out without any modification of the fabric and the results were compared. The dyeing parameters, mainly, dyeing concentration, temperature, time, and pressure in both water and scCO(2) mediums were studied. Also, the dye uptake expressed as colour strength (K/S) was measured for both dyeing mediums and it was observed that colour strength of the dyed polypropylene fibers in scCO(2) was significantly better than in water. The fastness properties (washing, rubbing, light and sublimation) of dyed samples in scCO(2) and water exhibited very good results. The ATR-FTIR of dyed samples in water and scCO(2) were found to be in good agreement with the structure of the dyestuff under application.