• Textile Coloration and Finishing
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• v.8 no.4
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• pp.52-58
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• 1996

Until now, in case of natural dyeing, the appearance of medium colors were achieved by repeat dyeing with different colorants after dyeing with one colorant. In this study, however, new dyeing method for appearance of medium colors was developed by use of mixing solution of different colorants prepared with the same ratio using colorant concentrates. In combination dyeing, purple color was difficult to represent because of the Gardenia blue dye among the colorants used in this study was naby blue dye. But the other medium colors such as yellow red, green yellow, green and blue green were easily represented by use of reddish Sappan wood and yellowish Gardenia concentrates. If the natural blue dye is prepared in concentrate condition, the dyeings dyed in various colors may be obtained by combination dyeing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.2
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• pp.177-184
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• 2013

This study was conducted to determinate the optimum times of transplanting and harvest for enhancing the fresh leaf yield and colorant level of an indigo crop, Persicaria tinctoria H. Gross, containing the blue dye indigo. Two cultivars, Naju Local and a new cultivar, NaramBlue, were transplanted 5 times from May 30 to July 10 at an interval of 10 days, and all of experiment plots harvested on Aug. 23 in Muan, the south area of Korea. As transplanting time was delayed, fresh leaf yield were maximum at earliest transplanting (May 30) and then decreased, while Niram (blue dye extract) and indigo content of fresh leaf remained almost constant though showed a small variation. Also, two cultivars transplanted on May 23 were harvested 5 times from Jul. 20 to Sept. 20 at an interval of 15 days. As harvest time was delayed, plant height, No. of first branches, and fresh leaf yield changed increasingly, while Niram content was increased to Aug. 20 and then decreased slightly. Indigo level increased largely to Aug. 5, and then continuously decreased with more delayed harvest. These tendencies of changes in fresh leaf yield and colorant level with different transplanting and harvest times were shown similarly in both cultivars. The results indicate that early transplanting before May 30 and harvest in early August will be appropriate for improving fresh leaf yield and colorant level.

• Textile Coloration and Finishing
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• v.14 no.3
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• pp.44-52
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• 2002

Recently there has been a growing interest in the use of natural dyes in textile applications. Natural dyes can exhibit better biodegradability and generally have a higher compatibility with the environment. In this study, the colorants of Catalpa ovata bark were extracted with water and analyzed by spectrophotometry for their main colorant species. Cotton, silk and wool fabrics have been dyed with aqueous extract of Catalpa ovata bark and their dyeabilities on the fibers were studied. Additionally the fastness to washing, drycleaning and light, and the effects on bacteriostatic rate and UV-B protection rate were also investigated. The major colorant of the extract of Catalpa ovata bark was shown to be 6-O-trans-caffeoyl-$\beta$-D-glucopyranoside. Cotton, silk and wool fabrics dyed with the extract of Catnip ovata bark were colored in yellowish red tint. The optimum dyeing condition of the colorants extracted from Catalp ovata bark was three repeated dyeing at $95^\circ{C}$ for 1 hr using post mordanting. For dyed silk and wool fabric, the fastness to washing were improved by mordanting, and the fastness to drycleaning were very outstanding. In case of wool fabric dyed with the extract of Catalpa ovata bark, the bacteriostatic rate was increased drastically by 98.0%, and UV-B protection rate was increased by 97.3%.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.1
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• pp.228-236
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• 1997

The browning characteristic and dyeability of the mushroom were examined to establish the optimum condition for browning and extraction in the process of obtaining the natural dye, brown colorant. The composition of browning extracts from mushroom was also analyzed and the dyeability were investigated. The results of this study are as follows, 1. The optimum condition for obtaining the browning colorant from mushroom was the crushed phase of sample. 2. The browning reaction by enzymes in mushroom was efficient at a temperature of 35$^{\circ}C$, a duratron period of 2 hr and pH of 8. 3. The optimum condition for extraction of browning extracts from browned mushroom was at 95$^{\circ}C$ and Ihr. 4. To analyze the content of browning extracts in the mushroom, three fractions were obtained from gel filtration using Sephadex G-25 and the fraction 1 was melanin and the fraction 3 was dihydroxyphenylanine (DOPA) and glutaminyldihydroxybenzene (GDHB) . 5. The turbidity in enzymatic browning extraction of mushroom increased depending on refrigeration storage (4$^{\circ}C$) and UV radiation. The filtration of the extracts resulted in a decrease of absorbance. 6. The dyeability of the fraction 1 was greater compared to that of the fraction 3 and that of wool greater compared to the other two fabric materiales.

• Textile Coloration and Finishing
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• v.7 no.4
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• pp.87-96
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• 1995

Colorant concentrates are prepared by use of concentration method of colorants extracted from Sappan wood using met hanol. Dyeabilities and fastness properties of silk fabrics dyed with concentrate of Sappan wood are investigated.The results obtained are as follows; 1. The storage stability of colorant concentrate is poor as concentration is excess. 2. Because the colors of dyeings are different with mordants, aluminium acetate, copper acetate, chromium alum and tin chloride are used in order to obtain reddish color. 3. The optimum dyeing temperature and dyeing time are 6$0^{\circ}C$ and 60 min, respectively. 4. Dry cleaning fastness is very good, and light fastness and washing fastness are low. 5. The dyeing method is simple owing to usehess of colorant concentrate prepared without extraction of colorant every time.

• Current Research on Agriculture and Life Sciences
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• v.28
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• pp.31-38
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• 2010

Extraction efficiency of colorants from red bean and black bean seed coat and its storage stability were examined according to the various extracting and storage conditions in this study. The obtained results were as follows ; The absorbance values of extracted colorants were increased with increasing extract time and temperature. pH 4 extracting was most efficient among the various pH conditions. The absorbance values of extracted colorant from red bean were increased with increasing extract time and temperature, when the extraction process was kept at $30^{\circ}C$ and $50^{\circ}C$, but it were decreased with increasing extract time at $70^{\circ}C$. In the case of black bean, it were also increased with increasing extract time and temperature. pH 5 extract was most efficient among the various pH conditions. In juice extractor system from red bean, the pH 5 of the pre-treatment was more efficient than the distilled water of pre-treatment. In black beans of the short-term pre-treatment with distilled water, the colorant was extracted better than at pH 5, but above 4 hours pre-treatment was decrease in pH 5. The Methionine added as a stabilizer gave the more effect to the stability of colorant from red bean the more Methionine addition. In the case of black bean 10mmol addition of methionine was more efficient than 20mmol.

• Textile Coloration and Finishing
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• v.15 no.6
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• pp.47-54
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• 2003

To be dyed with cationic Berberine, the cotton fiber was modified with reactive anionic agent. The Berberine, a natural cationic colorant of pure yellow, is the major component of Amur Cork tree extract and also can be employed as a natural antimicrobial agent due to its characteristic of cationic quaternary ammonium salt. By LC/MS analysis, it became obvious that the Berberine was contained in Amur Cork tree extract as a major color component. The adsorption of the Berberine on the cotton fabrics pretreated with the anionic agent was greatly increased comparing to that of untreated fabric. Because the anionic agent was colorless, it did not cause unintended color change of the dyeings. The dyed fabric with the Berberine has strong antimicrobial activity showing 99.5% of reduction of bacteria against Staphylococcu aureus.

• Textile Coloration and Finishing
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• v.23 no.3
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• pp.179-186
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• 2011

For the application of Jeju scoria scattered around the island as a natural dye, cotton fabrics were dyed with the dye and their properties were measured including dyeability, colorfastness, antibacterial activity, deodorization efficiency, ultraviolet protection, and far-infrared emission. The dyed cotton fabrics were in yellowish red and optimal dyeing conditions were obtained with a colorant concentration of 25%(o.w.b) at a temperature of $80^{\circ}C$ for the dyeing time of 120 minutes. The ratings of colorfastness to light, rubbing, perspiration, and washing were 8, 5, 5, and 4~5 respectively. After 15 wash cycles, colorfastness remained as much as 4~5 rating. The cotton fabric dyed with Jeju scoria demonstrated excellent antimicrobial activity and deodorization efficiency of 99.9% and 93.9% respectively. Ultraviolet protection factor was 50+. Far-infrared emission rate and far-infrared emission intensity were 90% and 362(W/$m^2{\cdot}{\mu}m$) respectively. The Jeju scoria can be introduced as a new colorant for the natural dyeing of cotton.

• Textile Coloration and Finishing
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• v.32 no.2
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• pp.89-95
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• 2020

In this study, the efficacy of Amaranth(Amaranthus spp. L.) as a natural dye resource was investigated for wool fabrics. It is known that a large amount of flavonoid and anthocyanin colorant are contained in leaves and stems, as well as red flowers. The optimum condition of dyeing was 1.3% of dye concentration(o.w.b.) at 100℃ for 60 minutes, resulting the K/S value, 23.43 and R Munsell color on the wool fabrics. Al, Fe, Zinc and Titanium were used as a mordant. The mordant improved the dye uptake, regardless of the mordant type and mordant method. The pre-mordanting method was more effective than the post-mordanting method. Al pre-mordanted fabric showed the highest K/S, 30.02. Light fastness and washing fastness were high in grades 4-5 and 5, and rubbing fastness was good in grades 4 and 4-5 in dry condition, but low in grades 2-3 and 3 in wet condition. The dry cleaning fastness was excellent in all 5 grades. However, the alkaline perspiration fastness ratings were low in grades 2-3 and 3. The results show Amaranthus spp. L. colorant can be used as a functional natural dye for wool fabrics.

• Fashion & Textile Research Journal
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• v.11 no.5
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• pp.818-826
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• 2009

Dyeability of microbial violacein produced from Chromobacterum violaceum CV107 on to multifiber fabrics has been studied. The bluish-purple colourants were produced by cultivation of Chromobacterum violaceum using LB liquid medium for 2 days. The colourant was extracted with 80% acetone and identified as violacein by LC/MS analysis. The violacein could be dyed on not only natural fibers such as Cotton, Silk and Wool but also synthetic fibers such as Diacetate, Triacetate, Creslan 61 and Nylon 66. Maximum K/S values were shown at 540-580 nm according to different fiber with color appearance of purple or blue. An optimum pH and temperature under dyeing condition were 10 and $70^{\circ}C$, respectively. Any mordants were not improved colour density and quality on various fabrics. From this studies, pigments produced microbe have a high potentials for natural dyeing on fabrics. Finally, development of new colourants from microbe has made a possible change for new dyeing field in respects of eco-friend and repeatability of natural dyeing for apparels.