• 한국의류학회지
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• 제35권7호
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• pp.736-747
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• 2011

This study investigates the current status and dyeing properties of various natural indigo powder dyes in the domestic market. Products from India, China, Europe are sold in the market and only a few manufacturers provide recommendation for the method of dyeing and information on the additives. Through the market research and the preliminary investigation on 21 products, 11 were selected for the dyeing experiment which include 3 Indian, 3 Chinese, 2 German, and 1 Pakistani origin indigo reduced powders, and 2 Indian origin dried indigo leaf powder. The two dyeing methods used were the precipitation method and the fresh juice method, both at $10^{\circ}C$, $25^{\circ}C$, and $60^{\circ}C$. Color difference, K/S value, and colorfastness of dyed cotton fabrics were examined. Indian reduced indigo powder showed the highest K/S value, deep dyeing, and the best color fastness. Chinese reduced indigo powder resulted in a more greenish and bluish color. Powders of dried indigo leaves were easy to use but resulted in a pale color due to low dye uptake.

• 한국염색가공학회지
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• 제12권3호
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• pp.174-182
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• 2000

We prepared natural indigo/calcium hydroxide complex powder from tinctoria's leaf, according to the demand of developing new dyeing technique of natural fibre with natural indigo. FT- IR and UV/Visible spectra were operated to find the dyeing properties of synthetic indigo and natural indigo powder. Cotton, flax and silk fabrics were dyed with different pH, dye concentration and dyeing time. The colour yield of indigo dye was quite sensitive to dye bath pH and fabric. In synthetic indigo, the highest K/S value of dyed silk fabric was shown at near pH 9.0, and which of flax and cotton fabric were shown at pH 11.0. In other hand, in the case of natural indigo complex powder, the highest K/S value of dyed silk fabric was shown at near pH 8.0, and which of flax and cotton fabric were shown at pH 9.5∼pH 10. Mercerized cotton fabric dyed with natural indigo powder has a little antimicrobial activity.

• 한국의류학회지
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• 제38권4호
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• pp.540-556
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• 2014

This research investigated the effective conditions to dye cotton with commercial indigo leaf powder. We tested dyeing conditions of: pH of dyebath (6.5, 9-12), heating ($20^{\circ}C$, $50^{\circ}C$, $70^{\circ}C$, $90^{\circ}C$), ageing (0, 0.5, 1, 4, 24 hours), reduction time (0, 30, 60 min), and dyeing temperature ($2^{\circ}C$, $10^{\circ}C$, $20^{\circ}C$, $50^{\circ}C$, $70^{\circ}C$, $80^{\circ}C$), dyeing was conducted for 20 minutes. The highest K/S value was obtained when cotton was dyed using pH 11 dyebath, heated at $50^{\circ}C$ for 30 minutes, aged for 24 hours at room temperature ($20^{\circ}C$), reduction carried out for 30 minutes, and dyed at $50^{\circ}C$. It is proposed that the K/S value is primarily influenced by the dyebath pH and dyeing temperature, followed by the presence or absence of ageing time and reduction time. The color of cotton with high K/S values was B type by Munsell hue value, which was similar to the color obtained in previous studies by freshly made indigo leaf powder and indigo leaf juice. The results indicate that the dyeing conditions established in this research are suitable to maximize the dyeability of commercial indigo leaf powder and that the indigo leaf powder can be used as a substitute for fresh indigo leaf juice.

• 복식문화연구
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• 제20권4호
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• pp.463-474
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• 2012

The purpose of this research was to find the suitable dyeing method for dyeing cotton fabric into indigo blue color using the raw indigo powder dyes sold in the Korean market. The research focused primarily on the comparison of the non-reduced dyeing method and the reduced dyeing method. The dyeing effects using different dyeing temperatures ($2{\sim}80^{\circ}C$) and different concentrations of reducing agent and alkali were also investigated. It was found that the reduced dyeing method must be used for dyeing cotton into indigo blue color using the commercial raw indigo powder dyes. The best result was obtained by $20^{\circ}C$ dyeing with the $40^{\circ}C$ dyeing giving a comparable result. The intensity of the blue color could be enhanced by increasing the alkali concentration. The non-reduced dyeing could not dye cotton fabric into indigo blue color at any given dyeing temperatures ($2{\sim}80^{\circ}C$). The reduce-dyed cotton fabrics showed a gradual color change upon repeated washing and extended sunlight exposure, the most color change occurring after the first two washing cycles and the first 5 hours of sunlight exposure. The standard tests of colorfastness showed that the reduce-dyed cotton fabrics had good to excellent colorfastness whereas the colorfastness of the non-reduce-dyed cotton fabrics were mostly poor.

• 한국의류산업학회지
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• 제13권2호
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• pp.263-268
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• 2011

One-step reduction/dyeing method was applied for ramie dyeing with natural indigo powder. The effect of reduction/dyeing conditions including the pH of bath, dye temperature and time, and concentration of indigo powder and reduction agent on dye uptake and color properties were investigated. Regardless of addition of alkali, the dyed fabrics appeared in the PB Munsell color range(${\lambda}_{max}$: 660 nm) and the dye uptake was much higher with no addition of sodium hydroxide. Dyeing was carried out through the use of only sodium hydrosulfite in the bath. The maximum dye uptake was obtained at 60 for 30min. Saturated dye uptake was obtained at 2 g/L of sodium hydrosulfite concentration up to 2 g/ L of indigo powder. Whereas, at higher indigo powder concentration (4 g/L), more than 3 g/L of reducing agent concentration was required for obtaining the saturated dye uptake. Color reproducibility was reliable with color difference in the range of 0.03~0.16. Regardless of color strength, fastness to rubbing was acceptable with a 3/4~4/5. Fastness to washing, dry cleaning, and light of samples with low color strength were poor. Whereas, fastness to washing, dry cleaning, and light of samples with high color strength were very good.

• 한국염색가공학회지
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• 제21권4호
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• pp.23-32
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• 2009

The objective of this study is to investigate the efficacy of leaf powder colorants as substitutes for traditional indigo dyeing. Leaf powder colorants were prepared by hot air($50^{\circ}C$) and room temperanrre($25^{\circ}C$) drying methods from fresh leaves. The presence of indigo in the leaf powder colorants was confirmed by UV/Visible absorption spectra. All the powder colorants showed broad absorption at 602 nm as same as synthetic indigo. Dyeing was done by reduction method with sodium hydrosulfite and sodium hydroxide. Leaf powder colorants produced blue color on silk fabrics, showing similar color to the one dyed traditionally with fresh juice extract. The powder colorants prepared at room temperature drying were more stable for long term storage than that prepared by hot air drying. Thus, the powder colorants prepared by room temperature drying was reduced and dyed in one-step process without sodium hydroxide in the dyebath for further investigate dyeing properties. K/S value of the fabric dyed without sodium hydroxide was much higher than one dyed with sodium hydroxide. Regardless of the addition of sodium hydroxide, rubbing fastness was fairly good showing above 4 rating. Fastness to dry cleaning and light of the fabrics dyed without sodium hydroxide were mote higher than that dyed in alkaline condition.

• 한국의류학회지
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• 제34권12호
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• pp.1933-1946
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• 2010

This paper is a comparative analysis of the $19^{th}$ century practice of indigo dyes and dyeing in Korea and England. From over hundreds species of indigo plants in the world, it was dyer's knotweed and woad that were cultivated in Korea; however, the only indigo plant grown in England was woad. Indigo dye was produced in the form of damp indigo sediment (jeon) in Korea; however, imported indigo (as a main dye) and couched woad (as an additional dye) were indigo dyes used in England. There existed three kinds of indigo vats, the ice vat, ash-water vat, and indigo sediment (jeon) vat, in Korea. The fresh leaves of indigo were used for both the ice vat and ash-water vat. The ice vat was very convenient for preparation, but had a weakness in the inability to produce a very deep shade of blue. The ash-water vat and indigo sediment (jeon) vat were in use for producing a very deep shade of blue. The indigo sediment Goon) vat was employed presumably only by professional dyers. The indigo vat practiced in England was categorized into two types; one was woad-indigo vat, and the other was an indigo powder vat prepared by using imported indigo rock. There was a tendency to adopt different kinds of indigo vats according to the material to be dyed. The woad-indigo vat was employed for the dyeing of wool. A few of chemical vats with imported indigo were adopted, especially for the dyeing of cotton. Indigo dyers in 19th century Korea were differentiated from the rest of the dyers. They managed the growing of indigo plants as well as the production of indigo sediment (jeon). Woad dyers in 19th century England handled woolen cloth as well as worsted and woolen yarn in general. However, they sometimes dyed silk skein as well. They produced several colors such as black, blue, slates, grays, by using both woad and imported indigo.

• 한국의류학회지
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• 제32권12호
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• pp.1963-1970
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• 2008

전통적인 니남쪽염료 제조법을 기준으로 굴껍질가루 대신 칼슘하이드록사이드를 사용하여 천연인디고분말염료를 만들었다. 제조한 인디고분말염료에 대한 텐셀의 염색성을 몇 가지 실험조건에서 조사하였으며 염색견뢰도를 측정하였다. 제조한 인디고분말염료는 약 15.5%의 인디고 성분과 0.757%의 인디루빈 성분을 함유하는 것으로 분석되었다. 환원과 염색을 자동염색기로 one-step으로 하였으며 환원제로 소디움하이드로설파이트를 사용하였다. 최대염착량은 $60^{\circ}C$에서 얻었으며 초기 20분 동안에 염착이 거의 이루어졌다. 본 연구의 실험조건 범위에서는 염료농도 4g/L까지는 2g/L의 환원제 농도에서, 염료농도 8g/L에서는 3g/L의 환원제 농도에서 최대염착량을 보였다. 텐셀은 염욕에 가성 소다를 넣지 않고 pH 5.75에서 염색할 때 훨씬 높은 염착량을 나타냈다. 염색견뢰도는 4/5-5등급으로 대체로 우수하였으며, 염착량이 낮을수록 더 높은 광퇴색을 보였다.

• 한국의류학회지
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• 제44권1호
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• pp.107-125
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• 2020

Indigo [鴉靑] was used as a symbolic color in 15^th century diplomacy. This study reinforces the historical research for characteristic and shapes of indigo colored royal clothing gift in King Seongjong's reign with a focus on po [袍] and ieom [耳掩]. Clothing made of fur that was combined with satin damask, silk gossamer [綃] were frequent gift, and a sable coat was a symbol of high-ranking clothes. Another clothing's materials were satin damask, sheer fabric gauze [羅], cotton, tabby with silk and ramie [紵絲]. The indigo color of King Seongjong's reign was recommended not for luxury. Historical research factors for indigo clothing gift were extracted from noblemen's relics. Danryeong and jigryeong are shaped of narrow sleeves and trapezoid gusset pleated in and out. Sable coat can consist of satin damask outshell, sable lining, and double oblique collar. Heohyung are presumed types of short sleeved fur vests. Ieom can be reconstructed with an indigo fabric outshell and sufficient fur. Dapho has gusset pleated wide and narrow. As additional gifts, the shapes of yoseon-cheopri and cheopri were analyzed. We selected a commercial fabric similar to relics and an indigo powder dyeing method to remedy a lack of traditional material. The reconstructed data were presented as flat drawings and samples.

• 한국약용작물학회지
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• 제21권3호
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• pp.213-219
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• 2013

This study was carried out to find out the optimum method of preparation of indigo standard solution and its stability, and to investigate the indigo contents in Niram, blue dye extract, from a total of 7 indigo plants and 34 breeding lines of Persicaria tinctoria H. Gross. Proper solvent for indigo standard was dimethyl sulfoxide (DMSO), and appropriate concentration was 1 mg of indigo in 10 mL of DMSO. Absorbance value of UV/Vis Spectrophotometer at 620 nm of standard solution was changed decreasingly 12 hours after the preparation of standard solution irrespective of the storage conditions such as temperature and light. Average value of absorbance of 8-fold diluted standard solutions prepared daily during 16 days was $0.210{\pm}0.005$, indicating the powder of indigo compound was stable chemically. Calibration curve was made for quantitative analysis of indigo of 7 Niram samples, and indigo contents ranged from 0.69% to 18.76% showing relatively larger variation. Across all 34 breeding lines, the range of indigo content was from 7.9 mg to 56.4 mg per 100 g of fresh leaves, averaging 25.2 mg of indigo content and showing a 47.7% coefficient of variation.