Corona discharge has been widely used to modify polymer surfaces because it can be operated at an atmospheric pressure in air. In this study, wool fiber and fabric were corona discharged, and afterwards wettability, laundry shrinkage, and frictional coef ficients were determined. An ESCA analysis was done to elucidate the changes of chemical composition on the fiber surface. The corona discharge incorporates oxygen atoms into the fiber and increases wettability and laundry shrink resistance of wool fabrics, but the effects are smaller than those from low temperature O2 plasma. After the pretreatment with corona discharge, the fabric was printed with color pastes of two acid dyes, and then treated with superheated or high pressure steam. The corona discharge pretreatment, in particular the single pretreatment, improved color depth considerably, which increased in the following order: untreated ≃O2 plasma treatment < three-fold corona discharge < single corona discharge. From these results it is likely that a small change in hydrophilic properties on the fiber surface plays an important role in improving the color depth of wool fabric in printing.
Desized and scoured cotton fabric is treated in a two-step process with sodium hydroxide/ liquid ammonia and liquid ammonia/sodium hydroxide to investigate the effect of the treatment sequence. Crystallinity, moisture regain, water absorbency, dyeability, and KES mechanical properties are measured. Despite a considerable decrease in crystallinity with both treatments, water absorbency decreases with NaOH/NH 3 and increases with NH 3 /NaOH compared with the untreated fabric. Furthermore, the NaOH/NH 3 treatment decreases the early dyeing rate with CI Direct Blue 1, whereas the NH 3 /NaOH treatment increases the rate remarkably compared to the untreated fabric. Nevertheless, saturation dye uptake with the same dye increases with both treatments compared with the untreated. As a measure of fabric hand, shearing and bending hysteresis curves are obtained with a KES instrument. The shearing modulus and shearing hysteresis width of the NaOH/NH 3 treated fabric are much smaller than those of the NH3 treated fabric, while those of the NH 3 /NaOH treated fabric are smaller compared with the NaOH treated fabric. From these results, it is clear that two-step processes such as NaOH/NH 3 and NH 3 /NaOH are much more effective for softening hand than the NH3 and NaOH treatments independently.Liquid ammonia treatment of cotton fabric is known to improve the softness of hand [I]. This treatment changes the crystallite structure from cellulose I to cellulose III. Water absorbency and dyeing properties with the treatment are almost unchanged, despite a considerable decrease in crystallinity [2][3][4][5][6][8][9][10][11].Although the decrease in crystallinity with the customary sodium hydroxide mercerization is smaller than that with the liquid ammonia treatment, dyeing properties increase considerably compared with the liquid ammonia, which greatly contributes to a soft hand [ 13]. Previously, we investigated the effect of liquid ammonia and sodium hydroxide/liquid ammonia treatments on mechanical properties with the KES instrument in relation to fabric hand [ 12]. It is clear that the sodium hydroxide/ liquid ammonia two-step process is much more effective at improving the softness of hand than liquid ammonia individually.In this paper, to obtain the highest hand softness and dyeing properties with a liquid ammonia treatment, we have treated cotton fabric with the following two-step processes-sodium hydroxide/liquid ammonia and liquid ammonia/sodium hydroxide. We have measured dye uptake with Cl Direct Blue 1 and mechanical properties with the t~s instrument, and we compare the effects of two-step processes with those of the sodium hydroxide and liquid ammonia treatments separately. ExperimentalDesized and scoured 40 thread count cotton fabric was mercerized with 20% sodium hydroxide (NaOH) solution for 1 minute at 20°C using a practical range and then treated with liquid ammonia (NH3) for 2 seconds at -33.4°C, also using a practical range to produce NaOH/ NH3 and NH3/NaOH treated cottons.The crystallinity of cotton fibers treate...
Wool and poly ( ethylene terephthalate) fabrics and film were treated with low-tem perature plasmas of helium/argon or acetone/argon under atmospheric pressure for 10 to 180 seconds. Although argon itself cannot independently generate a plasma under atmospheric pressure by applying high frequency voltage, it is easily generated by adding a small quantity of helium or acetone to argon gas. Wettability of the fabrics and surface tension of the film increased considerably with the treatment within 30 seconds. ESCA analysis was used to elucidate the surface chemical composition of fibers treated with atmospheric low-temperature plasma. Relative O1 s intensity in creased considerably and oxygen was incorporated in the form of —CO— and —COO— on the fiber surface. From these results, it appears that low-temperature plasma by atmospheric pressure discharge is effective for modifying the polymer surface, as it acts in the same fashion as low-temperature plasma by glow discharge.
ABSTRACT:In a previous article, we reported on the ozone-gas treatment of wool and silk fabrics in relation to the gas-phase processing of textile fabrics. The treatment incorporated an oxygen element into the fiber surface and contributed to an increase in water penetration into the fabric. In this study, nylon 6 and polyester fabrics were treated with ozone gas in the same way as that of the wool and silk fabrics. The treatment incorporated much more oxygen into the fiber surface in the form of OCOH and OCOOH, as shown by electron spectroscopy for chemical analysis. Water penetration increased considerably with treatment, and the apparent dyeing rate and equilibrium dye uptake were also improved, especially for the polyester fabric, despite an increase in the crystallinity. Therefore, it seemed that the treatment brought about a change not only in the fiber surface but also in the internal structure of the fibers (the crystalline and amorphous regions) with regard to the dyeing behavior. Further, the mechanical characteristics of the ozone-gas-treated polyester and nylon 6 fabrics were measured with a Kawabata evaluation system apparatus. The shearing modulus and hysteresis widths increased with treatment, especially for the polyester fabric. Therefore, it was clear that the treatment caused a change in the fabric hand to crisp.
We have investigated the rate of catalytic hydrolysis of cellulose fabrics by a cellulase enzyme in the presence of dyes on a cotton substrate. We found that both direct and reactive dyes on the substrate apparently inhibited the enzyme catalytic reaction, whereas a vat dye did not. The enzyme was more active for mercerized than for nonmercerized cotton. The enzyme treatment significantly reduced both tear strength and dye uptake of the fabrics. Enzyme-treated and successively dyed fabrics showed different color fading profiles compared to untreated fabrics after laundering.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.