Papers by Keyword: Dyeing

Abstract: In this work, a weft-knitted fabric produced from 100% meta-aramid (MA) fibre was functionalized by using polyelectrolyte, Poly (diallyldimethylammonium chloride) (PDDA), in order to modify its surface for dyeing with an uncommon dye class for MA fibres. Contact angle, dye solution drop adsorption, Scanning Electron Microscopy (SEM), reflectance spectrophotometry, washing and rubbing fastness tests were performed to study the effects caused by the interaction between PDDA and MA fabric. Good results of dyebath exhaustion with excellent values of colour strength were obtained for the samples previously treated with PDDA. These results showed the possibility of obtaining distinct and deep colours besides generating a lower energetic cost using shorter time and lower dyeing temperature as compared to those normally used in the MA dyeing process.

Abstract: This study evaluated the antimicrobial activity of PET-Silver nanocomposite filaments at different concentrations (0, 0.180%, 0.135%, 0.090%, 0.045% and 0.022% w/w) of silver nanoparticles in order to determine the minimum inhibitory concentration and minimum bactericidal concentration of silver incorporated in the PET matrix. The in vitro antibacterial activity was evaluated by the AATCC standard 100: 2012 method, against Staphylococcus aureus ATCC 6538, and Klebsiella pneumonia ATCC 4532. The filaments were tested after one and twenty-one months of preparation to evaluate the effect of time on the antimicrobial activity of the nanocomposites. Moreover, the antimicrobial activity was also evaluated after dyeing the filaments. The silver-free PET filaments have not demonstrated antimicrobial activity and cytotoxicity against human dermal fibroblasts. Nevertheless, excepted for the filament with 0.022% of silver nanoparticles, all PET-Silver nanocomposites reduced more than 99% the colony-forming units (CFU) of Staphylococcus aureus and Klebsiella pneumonia after one and twenty-one months of preparation. This suggests that the MIC of silver nanoparticles incorporated in the PET matrix is lower than 220 ppm (w/w) and the MBC is between 0.022 and 0.045% (w/w). However, after the dyeing process, no antimicrobial activity was observed for any PET-Silver nanocomposite filaments. This may be attributed to the release of silver from the PET matrix during the dyeing process or to the reaction/inactivation of the silver ions by the salts used in this chemical treatment.

Abstract: The method of electrochemical reduction utilizes electrons as agent to achieve the reduction of indigo, vat dyes and pollution emissions, as well as the recycling of electrolyte. In this study, Ca²⁺-Fe³⁺-triethanolamine (TEA) redox system was used as the mediator to achieve the indirect electrochemical reduction of indigo. The optimization of parameter was analyzed by reduction efficiency (RE) and current efficiency (CE). The result showed that indigo could be reduced by electrochemical method and the best optimization recipe was 20 g/L NaOH + 5 g/L Fe₂(SO₄)₃ + 30 g/L TEA + 5 g/L Calcium gluconate + 3 g/L indigo in 1 A·dm^-2 current density at 50°C. This work suggested that Ca²⁺-Fe³⁺-TEA redox system in reduction of indigo was an effective way with higher CE (75.9 %).

Abstract: We report herein, the synthesis of colorful nanofibers by electrospinning and dyeing with various class of dyestuff. Results revealed that dyes impart better color yield with the acceptable colorimetric values, color yield and color fastness. Morphology of nanofibers showed smooth surface of the dyed nanofibers under SEM. Cellulose nanofibers in particular, were prepared using precursor cellulose acetate and then converted into cellulose under alkaline treatment. Results revealed that dyes impart better color yield with the adequate color yield (KS) and color fastness. Morphology of nanofibers showed smooth nanofibers after dyeing under SEM. Based results obtained, the colorful nanofiber can be a better choice for advance apparel applications.

Abstract: The present study deals with the one-step one-bath dyeing of with/without alkaline treatment of twill weaved 50/50 cotton/polyester blended fabric using disperse dyes only. The dyeing results are studied by colorimetric colour measurements, applying instrumental approach, and colour change during fastness tests. Several testing methods are designed and adapted to the disposable technical and material base. The results are found to be promising as an alternative dyeing technology and for effective product quality assessment.

Abstract: Natural indigo dye was applied on silk fabric by using pad-batch and pad-dry techniques in the present of thiourea dioxide and sodium hydroxide. Alum (AlK(SO₄)₂), ferrous sulfate (FeSO₄), and stannous chloride (SnCl₂) were used as mordants. The colour of each dyed fabric was investigated in terms of the L*, a*, b* and K/S values. The effects of different dye concentrations with the use of applying padding techniques in the dyeing process was investigated. The colour fastness to washing, light, rubbing, water, and perspiration of dyed silk fabrics was performed according to the present ISO standard. Silk fabric was dyed by using a natural indigo colourant, applying one with metal mordant and one without giving the silk fabric a blue shade. However, a greenish blue shade was found as a dyeing result by adding a ferrous sulfate mordant. The fastness properties of washing, water, perspiration, and rubbing were very good level. However, a fair rating level was observed using a light fastness dyeing technique.

Abstract: The present of this study aims to the use of carboxymethyl cellulose (CMC) improving the ability of fiber in the dyeing process. Carboxymethyl cellulose was synthesized from cellulose of banana leaves by esterification method. The effect of carboxymethyl cellulose contents on the structure, thermal properties and dye absorption were also investigated. Then, the CMC/PP composite fibers were obtained from single screw extruder at various contents of CMC (1wt%, 3wt% and 5wt%). The results from XRD showed that CMC were good compatibility with PP composite fibers. The results of thermal analysis showed that the incorporation of CMC into PP did not affect the melt temperature of the composite fibers. After dyeing, the dye however was absorbed by the CMC/PP fibers more than the pristine PP fibers. The results of absorption of dye on the CMC/PP fibers from spectrophotometer showed that dye absorbability were significantly increased with CMC contents.

Abstract: This research was concerned with dye extraction from lac, purple corn cob, golden shower tree seed pods, garcinia dulcis bark and dried mangosteen leaves and application on cotton towel product dyeing by the use of exhaustion process. Cotton towel was pretreated using cationizing agent (Sarcat PD) before dyeing. Cotton towel dyed in the solution extracting from lac showed pink shade. The sample dyed with purple corn cob and golden shower tree seed pods resulted in violetish-brown and dark brown shades, respectively. With garcinia dulcis bark and dried mangosteen leaves the colour was yellow and brownish orange. The results showed that the dyes K/S values of the treated cotton towel were improved compared with those of the un-treated one.

Abstract: In this research, the dyeing behavior of silk fabrics with lac was studied. The effect of different mordants concentration (potassium aluminium sulfate or alum, stannous chloride, ferrous sulfate and sodium chloride) with simultaneous mordanting procedures using pad-dry and pad-batch techniques on colour characteristics of the dyed samples was investigated. The colour fastness tests were washing and light of the dyed samples, the test results were determined according to the present ISO standard.The results show that silk fabric dyed without and with stannous chloride and sodium chloride mordant gave a shade of light pink, while those mordanted with aluminum potassium sulfate, had noticeably pink shade. The colour shade was light grey shades was obtained by adding ferrous sulfate mordant. The washing fastness property showed very poor level, while light fastness was fair level.

Abstract: A natural colorant obtained from extraction of mangrove bark was applied on nylon fabrics via exhaustion process. Colorimetric data (CIE L*, a*, b* and K/S) were evaluated. Pre-, meta-and post-mordanting with different metal mordants (aluminium potassium sulfate, ferrous sulfate, copper sulfate, and stannous chloride) were also investigated. The colorant extracted from mangrove bark shows affinity to nylon fabric dyed without mordants. The highest color yield and uniform dyeing were obtained with post-modanting method.