An earthworm protease, Lumbricus rubellus, was used to improve the dyeing properties of protein fibers such as wool and silk. The optimal condition for the activity of the earthworm protease was about 40˚C at pH 7. The wool and silk were treated with the protease extracted from an earthworm and the K/S values of the dyed wool and silk were measured using a spectrophotometer in order to compare the dye uptake. The protease treatment enhanced the dyeing properties of protein fibers without severe changes in mechanical properties. The surface appearances of protease-treated fibers were observed by microscopy analysis.
Temporarily solubilized azo disperse dyes containing β-sulfatoethylsulfonyl group were applied to acetate fabric and the feasibility of dispersant-free dyeing was investigated. The color yields of the dyes on acetate fabric were found to be dependent on dye bath pH as well as dyeing temperature. The optimum results were obtained at pH 6 and 80℃. The dyes showed good exhaustion and levelling properties. Vinylsulfone derivatives of the dyes were prepared and applied to acetate with dispersant. Dyeing properties of the temporarily solubilized disperse dyes were similar to or better than those of the vinylsulfone dyes. The dyes showed moderate to good fastness properties on acetate.
The purpose of this study was to investigate the dyeability and antibacterial activity on wool fabric dyed with cochineal at variable dyeing conditions. Al, Cr, Fe, Cu and Sn were used as mordants and adsorption was compared with different mordanting methods. The optimum dyeing conditions of wool fabrics were dyeing concentration 2.0%(o.w.s), dyeing temperature 60℃, pH 3 and dyeing time 30 minutes. The pre-mordanting method was preferred for Al and Cr, and the post-mordanting one was preferred for Cu, Sn and Fe to achieve better dyeing. The optimum mordanting conditions of wool fabrics dyed with cochineal were mordanting concentration of 1%(o.w.s), mordanting temperature 60℃, and dyeing time 30 minutes. Wool fabrics dyed with cochineal showed a little antibacterial activity, but it was increased by Cu and Sn mordanting. The light fastness and perspiration fastness of wool fabric treated with cochineal were improved by mordanting.
Polypropylene fiber was dyed with 4 super hydrophobic dyes having different alkyl derivatives on the same chromophore. Double-tailed cationic surfactant, didodecyldimethylammonium bromide(DDAB), was used to make dye-dispersant complex to improve the dispersion of dyes. As the alkyl groups are longer and the hydrophobicity is increased, the dyeability onto polypropylene fiber was improved and deep coloration was obtained. As for the fastness properties, wash fastness was relatively good, while light fastness was bit low.
Upon UV/O3 irradiation cellulose acetate (CA) films showed modified surface properties such as increased hydrophilicity and surface roughness as well as increased dyeability to cationic dyes. UV treatment induced photoscission of acetyl groups in the main chain of CA resulting in decreased degree of substitution from 2.2 to 1.3. The slight decreases in reflectance and transmittance were caused by remarkably increased nano-scale surface roughness of the CA surface as much as 20-fold, which can destructively interfere with visible lights of wavelength lower than 500nm. Water contact angle decreased from 54o to 14o with increasing UV energy. Surface energy also increased slightly. The surface energy change was attributed to significant contribution of polar component rather than nonpolar component indicating surface photooxidation of CA film. The increased dyeability to cationic dyes in terms of both K/S and %E may be due to photochemically introduced anionic and dipolar dyeing sites on the film surfaces.
A mixed adsorbent prepared by pyrolysing a mixture of carbon and flyash in 1:1 ratio was tested for its decoloration ability for three different classes of dyes namely, Astrazone Blue FRR(Basic Blue 69), Teflon Blue ANL(Acid Blue 125) and Verofix Red(Reactive Red 3GL). Kinetic analyses were carried out at the optimum conditions obtained by the author in the previous studies. The data was fitted with three kinetic model equations. The results showed that the dye uptake mechanism followed the second-order rate expression.
A mixed adsorbent prepared by pyrolysing a mixture of carbon and flyash in 1:1 ratio was tested for its decoloration ability for three different classes of dyes, namely Astrazone Blue FRR(C.I. Basic Blue 69), Teflon Blue ANL(C.I. Acid Blue 125) and Verofix Red(Reactive Red 3GL). Equilibrium investigations were carried out at the optimum conditions obtained in the previous studies. The equilibrium data fitted reasonably well to both the Freundlich and Langmuir adsorption models. However the Langmuir model was more appropriate to describe the adsorption behavior of the dyes to the hybrid absorbent system compared with the Freundlich model. The mixed adsorbent can be an low-cost alternative to activated carbons.
The 1,3-bis(4-aminoaryl)squaraines showed color change behavior, they were found to undergo reduction with sodium borohydride in solution to give colorless leuco compounds, which oxidized readily in air back to the colored squaraine dye. We have shown that initial observations indicated that the derivatives synthesized gave new donor-acceptor chromophores. It is also interesting to note that the oxidation of the leuco squaraines did initially produce a species absorbing about 630-680 wavelengths. The 1,3-squaraines have found many uses as near-infrared absorbers, laser dyes and photoconductive materials. Furthermore their color-change redox behavior has potential in the area of peroxidase-based bioassaysas oxidation sensitive indicator systems were investigated.
This paper addresses the factors hindering the image quality of lines in inkjet printed on polyester fabric as printing media. Lines were printed onto different types of polyester fabrics in warp and filling directions. Line image quality including line width, edge blurriness, and edge raggedness was assessed. The effect of capillary wicking on line image quality of printed spun polyester fabric is discussed. The factors on the image quality include printing position(top of the yarn or between the yarn), printing direction(warp or filling), yarn structures(filament or spun), thread size(yarn or fiber), finishing, and ink properties(evaporation rate). More than 30% differences in image quality results were observed by changing the printing location on the spun polyester fabric. The best results of the image quality were obtained with the printed plain and spun polyester fabrics. The fiber sizes may affect capillary size; therefore, the image quality can be dissimilar. Types of finishing materials and inks greatly improve the line image quality on spun polyester fabrics.
There are many discrepancies between visually perceived color-difference and that which is quantified from an instrumental measurement when dark color samples are measured in the textile industry. The samples were prepared to represent these dark shades and the values of the instrumental results from conventional color-difference formulae(CIELAB, CMC, BFDⅡ, CIE94, LCD99 and CIEDE2000). Those of visual assessment were compared. The experimental results show that the CIELAB formula gives the best performance over other formulae, and the CIEDE2000 formula for the color-difference according to chroma presents the worst performance. Therefore, we can say that the problems in color matching of dark shades are caused by imperfect formula, because the results obtained from a color-difference formulae are different and the CMC which is used as a standard color-difference formula in the textile industry is not correct. So, a revised color-difference formula is proposed in this study, to account for these problems.
A new fastness formula based on the CIEDE2000 color-difference formula was developed by B. Rigg and his coworkers. It is much simpler to calculate the staining fastness grade than the ISO 105-A04 fastness formula based on the CIELAB color-difference formula. Sample pair sets, which cover a wide color space range were accumulated from the NCS(Natural Color System) color book. For those sample pair sets, a visual measurement experiment and an instrumental measurement experiment of fastness grade were carried out. Each performance of the ISO 105-A43 fastness formula and newly developed fastness formula was compared through degree of agreement for visual measurement results. The newly developed fastness formula indicated improved performance for measuring fastness grade as it was confirmed that the performance of the current ISO fastness formula ISO 105-A04 for assessing staining, was inadequate for measuring fastness grade. Then the fastness formulae were examined more closely according to the particular color spaces and the correlation of hue, lightness and chroma for measuring staining fastness grade was also considered to recommend more improved fastness formula. By modifying the weighting functions of CIEDE2000, which is a basis of new fastness formula developed by B. Rigg, a modified fastness formula is proposed in this study.
A data compression system has been developed by combining adaptive wavelets and optimization technique. The adaptive wavelets were made by optimizing the coefficients of the wavelet matrix. The optimization procedure has been performed by criteria of minimizing the reconstruction error. The resulting adaptive basis outperformed such conventional basis as Daubechies-5 by 5 10%. It was also shown that the yarn density profiles could be compressed by over 95% without a significant loss of information.