• Textile Coloration and Finishing
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• v.23 no.3
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• pp.169-178
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• 2011

The purpose of this study is to develop eco-printing method using natural dyes combined with chitosan treatment to impart various pattern effect on cotton fabric. It was examined whether tone-on-tone pattern effects could be produced by screen printing with chitosan paste and subsequently dip-dyed in natural dye bath. For polychromic colorants, fabrics were pre-mordanted and then screen printed with chitosan, while only chitosan printing treatment was applied for monochromic colorants. Color, dye uptake, washing, light and rubbing fastnesses of printed fabrics were measured in relation to the presence of chitosan printing. Pre-mordanting and chitosan printing treatment were applied to such polychromic colorants as madder, sappanwood, onion and cochineal. Also, printing pattern formation on fabrics was evaluated by differences in dye uptake and color. The results suggested that madder, onion and cochineal were effective on pattern formation. Regarding sappanwood, since dye uptake was increased only by pre-mordanting without chitosan printing treatment, there was little color difference and thus patterns were not clearly distinguished. Chitosan printing treatment tended to increase washing, light and rubbing fastnesses of dyed fabrics with polychromic colorants. Chitosan printing treatment was applied to monochromic colorants such as chlorophyll, gardenia and indigo and the effect of printing formation was examined according to the difference in dye uptake. Among monochromic dyes tried, chlorophyll was effective and chitosan printing improved washing and light fastnesses.

• Journal of Information Display
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• v.4 no.2
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• pp.29-34
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• 2003

We have studied liquid crystal (LC) molecular alignment on rubbed and photoaligned surfaces. Particular attention was paid to the intermolecular liquid crystalline interaction. We will first show that uniform molecular orientation on a rubbed surface does not mean spatially uniform interaction between the surface and LC molecules. Rather LCs tend to align themselves through LC interaction. The existence of nonuniformity of rubbing was successfully visualized by double surface treatment. The importance of intermolecular LC interaction was also found in the orientation formation process in 5CB evaporated on rubbed and photoaligned surfaces. By simultaneously analyzing polarized UVNIS absorption and second-harmonic generation (SHG) using the maximum entropy method, we succeeded in obtaining the temporal variation of the orientational distribution functions in the film forming process. The distribution anisotropy and pretilt are found to be generated under the influence of intermolecular LC interaction.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.6
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• pp.671-677
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• 2018

In this paper, we investigated the vertical alignment characteristics of liquid crystals (LCs) on fluorinated self-assembled monolayers (FSAMs). For comparison, a commercialized homeotropic polyimide (PI) layer was used as an LC alignment layer. We confirmed the successful deposition of FSAMs and the change of FSAMs before and after rubbing treatment through contact angle measurement and atomic force microscopy. The optical transmittance spectrum of the FSAMs is similar to that of the homeotropic PI layer, which is a superior optical characteristic applicable to LC devices. When FSAMs were applied to the vertically aligned (VA) LC cell, uniform and vertical LC alignments were achieved. In addition, the voltage-transmittance characteristic of VA LC cell with FSAMs was superior to that of VA LC cell with the conventional homeotropic PI layers. These results indicate that the FSAMs are suitable as the homeotropic LC alignment layer for enhanced LC devices.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.717-720
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• 2002

In this work, the electrical characteristics of organic thin film transistors with the surface-treated organic gate insulators have been studied. For the surface treatment, the simple rubbing technique was used. The field effect mobilities of the devices with PVP gate insulator was improved about four times as high as those of TFTs without the insulator surface treatment.

• Textile Coloration and Finishing
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• v.23 no.4
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• pp.263-273
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• 2011

Digital textile printing(DTP) technology made considerable advances in recent years. In this study, a pre-treatment agent has been prepared for the better coloration of digital textile printing. The ink formulation contained three kinds of 5g thickener (CMC, Sodium alginate, Dextrin), 25g urea, 5g sodium carbonate, and 465g distilled water. The optimal sharpness of outline was found in the 1-3% concentration of the pre-treating agent with a viscosity of 10-15 cSt. Even if the color difference between untreated and treated samples was not apparent in the printing step, the color appearance increased after steaming. The color appearance of cyan, magenta, yellow, black reactive colorants increased in the order of CMC>Sodium alginate>Dextrin. Wash fastness to shade change and staining for the treated samples were 4-5 rating, while untreated sample was 1-2 rating. Also, the pre-treated sample with 1:1 mixtures had 4-5 rating. Both dry and wet rubbing fastness to shade change and staining were excellent in the treated samples, whereas rubbing fastness of untreated sample was 1-2 rating. With exception of 3 rating to black color, light fastness properties were 4 rating for the remaining three colors in the regardless of treatment condition and mixing of pre-treating agents. Dry cleaning fastness of all samples were also 4-5 rating irrespective of treatment condition and mixing of pre-treating agents.

• Textile Coloration and Finishing
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• v.18 no.3 s.88
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• pp.31-41
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• 2006

Functional properties are available with sputtering. But sputtering treatment alone cannot got a good fastness performance to washing, rubbing and light. This research was objected to investigate optimum condition by sputtering on polyester through various processing conditions such as ion current and treatment time, and then various resin treated onto metal coated polyester fabrics in order to increase washing fastness of metal membrane. As the results, the optimum conditions revealed 1500 mA of ion current, 2 min of treatment time in sputter, and suitable resin concentrations were 2% of o.w.s (on the weight of solution) in resin treatment. Therefore, we could get enhanced anti-static effect and flex stiffness as well as washing fastness in sputtered polyester fabric with various resin treatment, for example, melamine and polyurethane.

• Journal of Fashion Business
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• v.15 no.5
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• pp.43-54
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• 2011

Digital Textile Printing(DTP) is appropriate for quick response system(QRS) and is closely connected with high value added fashion industry. Fashion products of high price are mainly silk and cotton. For high quality DTP products, it is important to optimize the parameters of media, pre and after-treatment, ink, printer, etc. DTP for these two fiber materials is also accompanied certainly with steaming as after-treatment process for coloration. Role of steam is like water in exhaustion dyeing. Steam can diffuse dye or ink in printing paste to fiber. Quality of DTP products depend on after-treatment processes such as steaming, washing, drying. Current production amount of DTP is smaller than one of conventional textile printing. However conventional after-treatment system has been using so far. This is mismatched with DTP in terms of process efficiency, spot work of small lot, quality control. In this study, continuous after-treatment system has been suitably designed for DTP that washing and drying are available after steaming. So, It is possible to improve efficiency of DTP process. Especially, the effects of after-treatment process, such as temperature of heat drum, steaming time on printability, color difference, color fastness were examined. Two types of samples(cotton knit and silk fabrics) were used. The results were obtained as follows : First, there is no a wide difference between the K/S values of cotton and silk treated with continuous after-treatment system and those of sample treated with conventional printing after-treatment method. So it is more effective to use the continuous after-treatment system than conventional printing after-treatment system in case of the daily throughput of 1,000 yards below. Second, after continuous after-treatment for DTP, K/S values were increased and lightness($L^*$) values were decreased. ${\Delta}E$ values were below 2.3. Third, DTP samples treated with continuous after-treatment system were tested for fastness(washing, light, rubbing). Grades of fastness(washing, light, rubbing) were above 3 grade.

• Polymer(Korea)
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• v.37 no.1
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• pp.52-60
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• 2013

Partially hydrolyzed cellulose acetate (CA) fibers were prepared by treating CA fibers in aqueous $Na_2CO_3$ solutions of various concentrations. The deacetylation of CA fibers was confirmed through FTIR spectra and WAXD patterns. The hydrolysis was confined to the surface part of the CA fiber by controlling the treatment conditions. The resultant fibers had a sheath-core structure with a sheath component of regenerated cellulose and a core of non-hydrolyzed cellulose acetate. The SEM images of the surface-hydrolyzed CA fibers, the core of which was dissolved out using acetone as the solvent, showed that the sheath thickness increased with increasing alkaline concentration, indicating an increase in the hydrolyzed fiber, i.e., regenerated cellulose. Polarized FTIR analysis of the polyimide film rubbed with velvet fabrics of surface-hydrolyzed CA fibers showed that polyimide molecules were preferentially oriented to the rubbing direction.

• Textile Coloration and Finishing
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• v.15 no.3
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• pp.168-175
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• 2003

Ultramicrofiber(UMF) PET knitted fabric and regular PET plain woven fabric as reference sample were impregnated with waterborne polyurethane(PU) in a two-step process with dyeing/PU treatment and PU treatment/dyeing to investigate the effect of the treatment sequence. The waterborne PU impregnated fabrics were dyed with two kinds of vat and disperse dyes to investigate the dyeing properties and the dyeing fastnesses. In vat dyeing the rank of color strength(K/S) was in order of dyeing/PU impregnation > dyeing only > PU impregnation/dyeing, whereas in case of disperse dyeing, the order was dyeing/PU impregnation > PU impregnation/dyeing >dyeing only. Wash fastness of vat dyeing showed a higher 2-3 grade than disperse dyeing, while rubbing and light fastnesses were not good for disperse dyes.

• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.12
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• pp.1310-1317
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• 2012

This study examines the possibilities to improve natural dyestuff's (Pinux$^{TM}$) dyeability and colorfastness for C/R (Cotton/Rayon (40/60)) and W/T (Wool/Tencel (10/90)) knitted fabrics in cationizing and smectiting for pre-treatment, simultaneous-treatment and post-treatment process sequences; as well as various other treatment methods. The sample dyeability showed the strongest K/S value in the order of smectite (S) < cationization + smectite (C+S) < cationization (C); however, the K/S value showed a low level in the simultaneoustreatment method of smectite. Colorfastness to washing improved in the order of C < C+S < S, and after the smectite post-treatment process, C/R improved from Grade 1 to Grade 4 and W/T improved from Grade 1-2 to Grade 4. Colorfastness to perspiration generally improved in the same order as the colorfastness to washing and after the smectite post-treatment process C/R, W/T sample's acidic and alkaline colorfastness to perspiration improved greatly. As for the colorfastness to rubbing, the addition of smectite in the simultaneous-treatment and post-treatment processes resulted in improved wet-colorfastness; however, smectite showed less effect on the colorfastness to light compared to other colorfastness ratings.