• Fibers and Polymers
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• v.7 no.3
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• pp.255-261
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• 2006

There is increasing interest in the many beneficial aspects of green tea to human such as anti-carcinogenic, anti-aggregant, anti-allergic, anti-bacterial, anti-mutagenic, and anti-oxidant activities. Besides these beneficial aspects, it has been reported that green tea ingredients, especially polyphenolic families (i.e., catechin), have some UV protection property both in vivo and in topical applications. In this study, green tea extract was used as a dyeing stock for cotton and the UV protection property of the dyed cotton fabric was examined. To increase the affinity of cotton fiber to the polyphenolic components in the green tea extract, a natural biopolymer, chitosan, was used as mordanting agent. The effects of chitosan concentration in mordanting on the dyeing characteristics and the UV protection property were examined. Chitosan mordanted green tea dyed cotton showed better dyeing characteristic and higher UV protection property compared with the unmordanted green tea dyed cotton. As the chitosan concentration in mordanting increased, the dyeing efficiency and the UV protection property also increased. Therefore, adapting chitosan mordanting in green tea dyeing can increase the UV protection property of cotton fabrics to some extent.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.5
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• pp.817-826
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• 2009

As UV radiation to the earth increased over recent years, many adverse effects of UV radiation have been reported. There are needs to develop UV-protective apparel and accessaries to protect skin from these harmful effects. Cellulose is one of the most frequently worn fiber during summer time. However, celllulose shows very low UV-protective property especially in case of thin and low fabric content. In this study, UV-protective cellulose textiles were developed using chiotsan mordanting and green tea dyeing. The repetition effect of chitosan and green tea treatment were focused. Three different cellulose fibers, cotton, linen, and ramie, were used for this study. All chitosan mordanted and green tea dyed fabrics showed increases in UV-protective property. The color of fabrics tended to darker as the numbers of mordanting process and green tea dyeing increased. UV-protective property did not increase significantly upon the repetition of mordanting and green tea dyeing treatment except ramie fabric. UV protective property was persisted upon washfastness test in all three cellulose fiber types.

• Fashion & Textile Research Journal
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• v.11 no.2
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• pp.344-349
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• 2009

Optimum dyeing conditions of green tea extracts were investigated toward nylon, cotton, rayon, and tencel fabrics. Affinity of green tea extracts was exhibited much higher onto nylon fabric than the other cellulosics. As for nylon, the adsorption was increased with the increase of dyeing temperature and optimum dyeing pH was around 4~6. Buildup property of green tea extract was good showing a linear relationship between concentration of the extracts and color strength of dyed fabrics within experimental range. Color fastnesses were good to excellent in general except to light.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.3
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• pp.385-390
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• 1999

Dyeing properties of silk fabric with green tea colorants were studied by investigating the effect of dyeing conditions such as concentration pH dyeing temperature and time on dye uptakes and effect of mordants on color change and dye uptakes, And various colorfastnesses of dyed fabrics were evaluated for practical use. Green tea colorants showed relatively good affinity to silk fabric and produced yellowish red color. Langmuir adsoption isotherm was obtained. Therefore it is considered that ionic bondings between colorants and silk fibers are formed. Mordants did not improve dye uptakes and affect color of dyed fabrics significantly. But mordanting adversely affected lightfastness of dyed fabrics. Regardless of mordanting colorfastness to perspiration especially in alkaline condition of dyed fabrics showed low rating compared with other colorfastness. It is concluded that mordanting is not necessary for silk dyeing with green tea colorants.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2004.04a
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• pp.296-301
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• 2004

We focused our research interests on the characteristic of silk fabrics dyed with green tea extracts and, moreover, revealed the catechin content of silk fabrics after dyeing with Korean tea extract by measuring the residues. Three kinds of green tea samples were taken between April and May, 2003, from Bosung(southern province in South Korea), in different terms as the first corp, the second corp, and the third corp. Before and after dyeing the silk fabrics with these extracts, catechins in the residue were analyzed by HPLC. Four kinds of Catechins, such as (-)-epicatechin(EC), (-)-epicatechin gallate(ECG), (-)-epigallocatechin (EgC), (-)-epigallocatechin gallate(EgCG) were isolated from Korean green tea extracts. Catechine contents in Korean green tea leaves depend on the making process such as heating and steaming, and the younger the richer. The absorbed catechins in sillk fabrics after dyeing followed in a decreasing order of EgCG>EgC>ECG>EC. We have found a 68% uptake of EgCG, and 116.8mg/g of EgCG in the silk fabrics after dyeing with 1% Korean green tea extracts.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.4
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• pp.510-516
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• 1999

Dyeing properties of cotton fabrics with green tea colorants were studied by investigating the effects of dyeing conditions such as colorants concentration. pH dyeing temperature and time on dye uptakes effects of mordats on dye uptakes and color change and effects of cationizing agent on dye uptakes. And various colorfastnesses of dyed fabrics were evaluated for practical use. Green tea colorants showed low affinity to cotton and produced yellowish red color. Freundlich adsorption isotherm was obtained thus it is considered that hydrogen bondings are formed between colorants and cotton. Dye uptake was maximum at pH 5 and decreased as pH increased. Mordants especially Cu and Sn were effective for increasing dye uptake. Dye uptakes were improved remarkably by cationizing. Cationized cotton showed Langumuir adsorption isotherm indicating that ionic bondings were formed between colorants and cationized cotton. While mordanting did not affect lightfastness cationizing affected adversely. Colorfastness of cationized sample was generally inferior to that of mordanted samples.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.6
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• pp.745-752
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• 2005

Green tea has various medical effects. It was selected as new natural dyes guessing the effects of the biological activities are still appeared on dyeing. It was examined whether they have the function of Uv-blocker or not. Cotton, linen & Hanji were dyed with Green tea. Al, Cr, Cu, Fe and Sn were selected as the mordant and the UV blocking rate of dyed samples was measured. The results of this study as follows; 1 . The color of dyed samples with Green tea changed yellowish red except Hanji and linen mordanted with Fe. 2. K/S values of dyed samples with Green tea increased by the number of dyeing treatment(p<.01). 3. UVA and UVB blocking rate increased by the number of dyes. Cotton and Linen could block the UV radiation over $93\%$ and Hanji could block over $95\%$ after three times of dyeing. These results suggest that Hanji has possibility far various practical uses of clothing material in beautiful and functional aspect. It could have the biological effects when we put on dyed clothing material with Green tea.

• Journal of Fashion Business
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• v.23 no.1
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• pp.64-73
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• 2019

The objective of this study was to investigate dyeing characteristics of silk, cotton and rayon fabrics using dyeing solution extracted from different varieties of tea. Comparative results of CIE Lab values of 360 pieces of dyed fabrics were studied to quantify the effects of dye concentrations (100%, 150%, and 200%) and mordants (Fe, Cu, Sn, Al). In addition, the color difference values (${\Delta}E$) of the dyed and mordanted fabrics were evaluated. The results of the study were as follows: First, among all of the 360 pieces of silk, cotton and rayon fabrics, the best dyeing effects was observed on silk fabrics. Second, the dyeing effect of the eight different types of tealeaves belonging to green tea, oolong tea, black tea, and dark tea tended to enhance as the degree of fermentation increased. Third, when the fabrics were mordanted with Fe, Cu, Sn, Al mordants, various colors such as brown, brownish red, brownish yellow, gray, and reddish brown were obtained.

• Textile Coloration and Finishing
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• v.18 no.1
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• pp.10-19
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• 2006

Despite several recent attempts to measure the concentration of individual catechins by HPLC, it has not been so easy to separate catechins accurately. The aim of the present work is to provide a proper condition for separating each component of catechins by HPLC analysis, and also to evaluate the experimental variables including color differences, and metal ion contents after dyeing and mordanting. Four kinds of Catechins, (-)-epicatechin(EC), (-)-epicatechin gallate(ECG), (-)-epigallocatechin(EgC), (-)-epigallocatechin gllate(EgCG) were isolated from the residues after dyeing. Catechins in Korean green tea leaves are richer when e tea leaves are younger. Higher concentration of catechins owes it to e way it is processed. The contents of catechins adsorbed in silk fabrics after dyeing were in order of EGCG>ECG>EGC>EC. We have found $68\%$ uptake of EGCG, and 116.8mg of EGCG in the silk fabrics after it was dyed with $1\%$ Korean green tea extracts. The absorbance intensity and K/S values of dyed silk fabrics were increased with dyeing temperature and time. Only the surface color of the silk fabric dyed with green tea extracts was yellowish red, but it changed from yellowish red to red with an increase in the mordant concentration. Post-mordanted silk fabrics with ferrous sulfate changed from yellowish red to red and purple color shade. In a practical evaluation, there is no significant change in color after twenty times of the continuous dry cleaning process. However, post-mordanted fabrics with ferrous sulfate faded the brightness of color after dry cleaning. Dyeing silk fabrics with a Korean tea extract reduced the metal ion contents in the silk fabrics when compared to the untreated silk fabrics. Metal contents in silk fabrics dyed and post-mordanted with $1\%$ each metal solution were 0.194 ppm for Aluminum, 1.601ppm for Copper, and 0.334 ppm for Iron. After the post-mordanting process, the heavy metal ion absorption increased, which was mainly attributed to the catechins and polyphenols in dyed silk fabrics.

• Textile Coloration and Finishing
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• v.18 no.6 s.91
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• pp.80-87
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• 2006

Nowadays, interests of ultraviolet(UV) protection increased, since the UV dosage on the earth surface has increased over years. Overdose of UV can cause various skin, eye, and even DNA damages. Therefore, it is need to develop a proper mean to protect human skin and eye from UV radiation. In this study, the UV protective effect of green tea extract dyed fabrics with various fiber types were examined. Green tea has an active moiety called 'catechin' having benzene rings in its structure, which would exert a proper UV protective property. Green tea dyed fabrics showed the increase in UV protection, and silk showed the highest increase in UV protection (from 52.2% to 84.5% in UV-A, from 66.1% to 90% in UV-B). The order of UV-A protection increase is silk, wool, nylon and acrylic, PET, and cotton. The order of UV-B protection increase is silk nylon, wool, acrylic, cotton, and PET. In case of silk and nylon, the UV protection property gradually increased as the concentration of green tea extract increased. As a result, it was proven that green tea extract dyeing can improve UV protection property of dyed fabrics in environment-friendly and biocompatible manners.