Cotton fabrics were immersed in aqueous solution of N-methylmorpholine N-oxide(NMMO) with various concentrations, padded by 300% of pick-up, concentrated at 90℃ for 30min under constant-length condition, washed, and dried, to examine a possibility of linen-like finishing by the solvent bonding between fibers. With increasing the concentration of NMMO, cross-sections of fibers changed to oval or polygonal shapes and not only the fibers but also the warp and weft were bonded each other, which produced linen-like effect on the fabrics in the aspects of appearance and mechanical properties such as the increase of stiffness and shear properties. The thickness, moisture regain and dyeability were increased with the concentration of NMMO.
Poly(trimethylene terephthalate)(PTT) and Poly(ethylene terephthalate)(PET) fibers were annealed at various temperatures ranging from 100℃ to 230℃ for 10 min under tension and tension free. Dyeing rates and absorption isotherms of both fibers were obtained with C.I. Disperse Red 60 at 100, 120 and 130℃ in water system. Also X-ray diffraction pattern, moisture regain and water absorption were investigated. The dyeing rate of PTT fiber is faster than PET fiber, and dyeing of PTT fiber begin at lower temperature compared to PET fiber. The absorption isotherms from both fibers with disperse dye are nearly linear up to the saturation dye uptake, which increase with dyeing temperature. Equilibrium dye uptake of PTT fiber annealed under tension above 180℃ was remarkably decreased because of a changes in the fine structure of fiber. The intensities of X-ray diffraction peaks of both annealed fibers were increased with increasing in annealed temperature. The reflections observed at 2θ= 15.8o, 24o and 25.2o were assigned reflection of crystal at the planes of (0 1 0), (1 2, 1 2), and ( 3, 1 3) respectively, and the peak became sharp with heat setting temperature.
Poly(ethylene terephthalate)(PET) filaments of regular(monodenier 2.08d) and ultramicrofiber (monodenier 0.05d) were treated with dimethylformamide(DMF) to observe the structure change of the PET such as shrinkage, density, X-ray diffraction of the UMF treated with DMF were measured. Also, dyeing experiments were performed to see the effects of DMF. The dyeability was improved by DMF treatments, and the equilibrium dye uptake increased in spite of the increase in the density and birefringence and crystallinity. The heat shrinkage appeared in PET UMF treated with DMF at 80℃ by TMA, DSC, and Reovibron analysis and Tm peak was shown by DSC analysis.
Nylon 6 and polyester taffeta fabrics are dyed in aqueous medium with vat dyes such as Indanthren Red FBB, Mikethren Blue ACE and Mikethren Blue HR varying the compositions of sodium hydrosulfite and NaOH. Also nylon UMF nonwoven and polyester UMF knitted fabrics are dyed with metal complex and disperse dyes as a reference, and the wash and rubbing fastnesses for these dyes are investigated. In vat dyeing of polyester and nylon taffeta, an optimum composition of sodium hydrosulfite/NaOH is existed at a range of 1∼2wt%/0.2wt%. A good build-up property for Mikethren Blue ACE on nylon 6 UMF nonwoven fabric is shown at high temperature. Vat dyeing of polyester with Mikethren Blue Ace shows a good color shade in a higher temperature, while dyeing with Mitsui Blue HR shows low temperatures. Vat dyes in dyeing of both nylon 6 UMF nonwoven and polyester UMF knitted fabrics have a better wash fastnesses compared with metal complex or disperse dyes.
The effects of various parameters on partial decoloration of cotton dyeings using discharge reactive dye were investigated. The decoloration of dyed cotton fabrics with varying pH were very sensitive below 100g/l of amount of potassium carbonate. Our results did indicate any significant changes in color when the amount of Rongalite C in reducing liquor was increased 150g/l to 200g/l. The steaming time had significant effects on fade-out, with an steaming time of 3∼5 min. being sufficient for decoloration build up. The change of color below 130℃ was not significant and it only become evident above 140℃. The additional color changes did not cause by washing under suitable concentrations of oxidation and neutralization agents. The decoloration treatment did not affect the mechanical property of cotton fabrics such as tensile strength.