• Title/Summary/Keyword: color strength(K/S)

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Improving the Dyeability of Cotton Fabric with Caesalpinia sappan through Pretreatment with Gelatin (면직물의 젤라틴 전처리에 의한 소목염색의 염색성 향상)

  • Lee, Ji Youn;Jang, Jeong Dae
    • Fashion & Textile Research Journal
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    • v.21 no.4
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    • pp.509-514
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    • 2019
  • Cotton fabrics were treated with gelatin to enhance dyeability and color strength when using Caesalpinia sappan dye. Gelatin was used as the protein and a pad-dry- cure method was used for the treatment process (2, 4, 6, 8, 10, 12, 14g/l concentration). Pretreated fabrics were mordanted with 10% alum. Fabrics were then dyed with freeze-dried sappan wood water extract powder form. Dyed samples were assessed in regards to dyeing behavior and color fastness. Comparing untreated and gelatin treated samples from the SEM images indicated that the Gelatin treatment (10g/l) resulted in an enhanced surface roughness that was relative to that of untreated cotton. Padding cotton with gelatin at 6g/l concentration afforded dyed fabrics with a 2 times increase in the K/S value over that of untreated fabrics. All dyed samples were red color with a significant enhancement in the sample color strength (K/S) being observed for pretreated samples. pH values favor dye absorption with pH 7 yielding the highest color strength. Dyeing at an elevated temperature resulted in a lower color strength and reddish-dull color. Longer dyeing times created greater color strengths for untreated and gelatin treated cotton. Increased dye concentrations resulted in higher K/S values for both gelatin treated and untreated cotton. As for color fastness, gelatin treated and untreated cotton fabrics dyed with sappan wood extract showed a relatively low rating in washing fastness (color change 1 rating), light fastness (1 rating), and rubbing fastness (wet:1-2, dry:3-4 rating).

A STUDY ON FRACTURE STRENGTH AND COLOR BY THE DESIGN OF METAL COPING IN CERAMO METAL CROWN (내부금속관 형태에 따른 도재전장금관의 파절강도와 도재색조에 관한 연구)

  • Lee Myung-Ho;Jeon Young-Chan
    • The Journal of Korean Academy of Prosthodontics
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    • v.30 no.1
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    • pp.103-124
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    • 1992
  • The purpose of this study was to investigate the effect on the fracture strength and color of ceramic by the design of the metal coping in ceramo metal crown. In this study, four types of ceramic crowns were made for fracture strength : standard ceramo metal crown, collariess ceramo metal crown, modified ceramo metal crown, and ceramic jacket crown. And three types of disk formed-specimens were made to compare the dentin shade owing to aluminous opaque powder and palladium alloy. Fracture strength was measured by universal testing machine(Instron Co. Ltd., U.S.A) and color was measured by color and color difference meter(Yasuda Seiki Seisakusho, Ltd., Japan). The results were as follows : 1. The fracture strength of ceramic was affected significantly by the design of metal coping in ceramo metal crown. The mean fracture strength(192.0 Kg) of standard ceramo metal crown was about 1.7 times higher than that(111.5 Kg) of collarless ceramo metal crown, and about 2.8 times higher than that(67.8 Kg) of ceramic jacket crown. 2. Modified ceramo metal crown that has metal band in the labio cervical had the lowest fracture strength. 3. Lightness, yellowness and redness of the dentin fired were decreased by the metal coping.

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Dyeability and Functionality of Silk Fabrics Dyed with Buckwheat Extracts (메밀 추출물에 의한 견직물의 염색성 및 기능성)

  • Kim, Sangyool
    • Journal of Fashion Business
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    • v.22 no.4
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    • pp.106-117
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    • 2018
  • The present study was conducted to investigate dyeing properties and functionality of silk fabrics dyed with extracts from buckwheat skin. Comparative results of color strength(K/S) values of dyed silk fabrics were studied to quantify the effects of dye concentrations, dyeing temperatures, dyeing time and the pH; the effect of mordants; and color changes. And also evaluated the fastness, antimicrobial property, ultraviolet protection properties of the dyed and mordanted silk fabrics. The color strength(K/S) values of silk generally increased depending on the increasing dye concentration, dyeing temperature, and dyeing time. And the highest color strength values were obtained at a dye concentration of 100%(v/v), a dyeing temperature of $90^{\circ}C$, a dyeing of time 80 minutes, and a dyebath of pH 2. The color fastness to light of dyed and mordanted silk fabrics were found to be good, and the drycleaning and rubbing fastness were excellent. The fade of washing fastness was not good, however, the stain of washing fastness and perspiration fastness showed relatively good grade. The Al, Cu, Fe mordanted silk fabrics(except Fe for Klebsiella pneumoniae) showed 99.9% reduction rate. The ultraviolet protection properties of the mordanted fabrics were generally improved. Moreover, the Cu and Fe mordnared fabrics showed very exceptional ultraviolet protection factors.

FLEXURE STRENGTH AND COLOR CHANGE OF REUSED IPS EMPRESS 2 (반복 사용된 IPS Empress 2의 굽힘강도와 색변화에 관한 연구)

  • Song Young-Kuk;Kim Yu-Lee;Kim Sung-Hoon;Ahn Hee-Young;Jin Tai-Ho
    • The Journal of Korean Academy of Prosthodontics
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    • v.41 no.1
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    • pp.71-80
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    • 2003
  • Development of new ceramic and esthetic need of patient increased the use of ceramic restorations. The purpose of this study was to confirm the possibility of recycling for IPS Empress2 which has a lot of advantages in esthetics. 1st, 2nd and 3rd pressed disc-shaped($10{\times}1.5mm$) IPS Empress 2 specimens were made with IPS Empress ingot(shade 200, Ivoclar, Liechtenstein) and pressing furnace(IPS Empress EP 500, Ivoclar, Liechtenstein). Flexure strength was measured with universal testing machine(Zwick 145641, Zwick, Germany), and color change and staining resistance of specimens were evaluated with colorimeter (Model TC-6FX, Tokyo Denshoku Co., Japan). The followings were drawn from this study : 1. Flexure strength of the 1st, the 2nd, and the 3rd pressed specimens showed 236.78 MPa. 247.16MPa, and 220.72MPa, respectively. Flexure strength of the 2nd pressed specimens was higher than others, but there's no statistical difference between them. 2. The color difference between the 1st and the 2nd pressed specimens was 3.25, and that between the 1st and the 3rd pressed specimens was 3.63(P<0.05). 3. The color change after staining of the 1st, the 2nd. and the 3rd pressed specimens were 1.43, 2.64, and 1.45, respectively. In this study, reused IPS Empress 2 specimens showed insignificant change of flexure strength and stain resistance, but they showed some color change according to reuse. From this results, the limited possibility of reuse for IPS Empress 2 could be considered.

Optimization of Silk Dyeing with Natural Indigo (천연인디고를 이용한 견직물 염색의 표준화 연구)

  • Son, Gyeong-Hui;Sin, Yun-Suk;Ryu, Dong-Il
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2008.04a
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    • pp.102-104
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    • 2008
  • Natural indigo dye was prepared by extracting from Polygonum tintorium, precipitating with calcium hydroxide, and dried. Dyeing was carried out using sodium hydrosulfite as a reducing agent for the prepared natural indigo powder. K/S value, color property, and colorfastness of dyed fabrics were investigated. Optimum dyeing conditions obtained were 60$^{\circ}C$, 20min. Regardless of indigo dye and sodium hydrosulfite concentration, Munsell hue of dyed fabrics was PB color. Compared to the dyed fabric with both sodium hydroxide and sodium hydrosulfite, those with sodium hydrosulfite only showed higher color strength(K/S value). Colorfastness of dyed fabrics showed high rating except of wash/dry cleaning fastness of silk fabrics dyed low color strength.

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Natural Indigo Dyeing by Using Glucose Reduction (포도당 환원을 이용한 천연 인디고 염색)

  • Shin, Youn-Sook;Cho, A-Rang;Yoo, Dong-Il
    • Textile Coloration and Finishing
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    • v.21 no.3
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    • pp.10-18
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    • 2009
  • Dyeing process of the natural indigo powder onto ramie and silk fabrics was investigated by using glucose and calcium hydroxide as a reducing system. Effect of reduction and dyeing conditions such as temperature and time of reduction/dyeing, and concentrations of glucose and calcium hydroxide on the dyeing process were explored. Indigo powder was obtained by drying the conventional niram paste in an oven at $50^{\circ}C$. Color strength of the dyed fabrics was evaluated by K/S value measured at the wavelength of maximum absorption(${\lamda}$max). Munsell color coordinates(H V/C) were used to compare fabric colors of ramie and silk. Ramie fabric showed purple-blue color for all the temperature and time. On the contrary, silk fabric showed wide range of color including brown, brown-green, green at the different temperature. With the increase of K/S value, the coordinate of value(lightness) decreased for both of ramie and silk fabrics. The coordinate of hue(shade) changed drastically with the increase of K/S value for silk fabric, compared with that of ramie fabric which showed nearly constant value at the whole range of K/S value. Optimum concentrations of calcium hydroxide were for 6 g/L for ramie and 4 g/L for silk at $60^{\circ}C$ and 50 min. K/S value increased with the indigo concentration. Maximum K/S value was shown at $10{\sim}12$ g/L of glucose concentration. For both of ramie and silk fabrics, the colorfastness of washing and light was lower than that of rubbing. All the colorfastness values were improved with the increase of color strength.

A STUDY ON THE COLOR STABILITY AND SHEAR BOND STRENGTH OF DENTURE REPAIR RESINS (의치 수리용 레진의 색안정성과 결합강도에 관한 연구)

  • Jin, Tai-Ho
    • The Journal of Korean Academy of Prosthodontics
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    • v.33 no.1
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    • pp.24-31
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    • 1995
  • This study was performed to investigate the color stability and shear bond strength of denture repair resins. The denture base resins used in this study were Premium Super-20(Lang Dental Mfg. Co., Inc.,.U.S.A.) as heat curing resin, Triad VLC Denture Base(Dentsply/York Division, U.S.A.), Triad Reline Material(Dentsply/York Division, U.S.A.), Repair Acrylic(Lang Dental Mfg. Co., Inc.,. U.S.A.), Toughron Rebase (MikiChemical Product, Kyoto, Japan), and Tokuso Rebase(Tokuyama Soda Co., Ltd., Japan) as denture repair resin. After fabrication of specimens, they stored for 20 months, then color changes and shear bond strength were measured by colorimeter(Model TC-6FX, Tokyo Denshoku Co.) and Instron Universial Test Machine. The results were as follows : 1. There were changes of $L^{\ast},\;a^{\ast},\;b^{\ast}$ and $DE^{\ast}$ in Triad VLC Denture Base after 20 months. 2. There were changes of $a^{\ast}$ in Toughron Rebase and Tokuso Rebase, and $b^{\ast}$ in Tokuso Rebase after 20 months. 3. The shear bond strength of Repair Acrylic and Toughron Rebase were higher than that of Tokuso Rebase and Triad Reline Material.

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A Study on Photofading of Cellulose Fabrics Dyed with Safflower Red Colorants (홍화의 홍색소로 염색한 셀룰로오스계 직물의 광변퇴색 고찰)

  • Shin, Youn-Sook;Choi, Seung-Youn
    • Journal of the Korean Home Economics Association
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    • v.46 no.10
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    • pp.1-9
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    • 2008
  • The purpose of this study was to increase uv-cut ability of cotton, ramie, and rayon fabrics dyed with safflower red colorants. For this purpose, samples treated with uv-cut agent and tannic acid were compared with the untreated samples after ultraviolet(uv)-light exposure in terms of K/S value, color changes(${\Delta}E$), SEM, and tensile strength retention. K/S value rapidly decreased with increasing exposure time, but K/S value of the samples treated with both uv-cut agent and tannic acid decreased less than that of untreated samples. As increasing exposure time, $L^*$ and $b^*$ increased, $a^*$ decreased, and so ${\Delta}E$ increased, indicating less red character and more yellow character in color. This leads to change hue, value and chroma value. But color change of samples treated with both uv-cut agent and tannic acid was less than that of untreated samples. SEM pictures showed a severe degradation by uv exposure in all samples. Tensile strength slowly decreased for 21 days. And after this point, the decreased proceeded more rapidly. Tensile strength retention of the samples treated with uv-cut agent and tannic acid was higher than that of untreated samples.

Hair-dyeing by using Pomegranate Hull Extract (석류 과피 추출물을 이용한 모발염색)

  • Cho, A-Rang;Shin, Youn-Sook;Yoo, Dong-Il
    • Textile Coloration and Finishing
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    • v.20 no.6
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    • pp.42-50
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    • 2008
  • The objective of this study is to investigate the efficacy of pomegranate hull colorant as a natural hair coloring dye. The extract of pomegranate hull was concentrated and freeze-dried to get colorant powder. Effect of dyeing condition and mordanting on the dye uptake of hair by using Al, Fe, Cu, Cr, Sn compounds, color change and colorfastness were explored. In addition, tensile strength was measured and the surface of the hair was observed. Dye uptake of hair measured by K/S value (400 nm) indicated that ionic bonding seems to be involved in the sorption of pomegranate colorant to hair. Maximum sorption was obtained at pH 3.5 and the concentration of 50% (on the weight of hair, o.w.h.). Acidic dyeing condition (pH $3.5{\sim}5.0$) showed yellow color however alkaline dyeing condition (pH $7{\sim}11$) gave reddish yellow color. Pomegranate hull colorant produced greyish brown color on hair and the hair mordanted with Fe showed dark brown color. Mordants except Fe did not increase dye uptake significantly. Mordants except Cu increased light fastness and mordants except Cr increased washing fastness level slightly. According to SEM observation and the tensile strength retention measurement, the mordant dyed hair gave more damage to hair by ultraviolet light and washing than the hair dyed without mordanting. Experimental results of K/S value and colorfastness(light and washing) supported that pomegranate hull colorant without mordanting can be used as a semi-permanent natural hair coloring dye.

Natural Dyeing of Silk Fabrics with Undaria Pinnatifida Extracts (미역 추출물을 이용한 견직물의 천연염색)

  • Kim, Sangyool;Jeon, Soonduk
    • Journal of Fashion Business
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    • v.18 no.5
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    • pp.69-81
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    • 2014
  • Fabric made of 100% silk was dyed with Undaria pinnatifida extracts under different conditions such as varing colorant concentration, temperature, time and dyebath pH. The dye uptake (K/S, value), CIE L*,a*,b* and Munsell values of the dyed samples and mordanted samples were measured. Colorfastness, antibacterial property and UV protection property were also evaluated. As colorants concentration increased, the dye uptake increased progressively and maximum color strength was obtained at 100% V/V. Dye uptake also increased with increasing temperature and time, and the maximum color strength was obtained at $80^{\circ}C$ and 60min. With pre-mordanting, the color of the Al and Fe mordanted silk fabrics was yellow on the Munsell color system, while the Cu mordanted fabric was a greenish color. Al and Fe post-mordanted fabrics had a yellow tone, and the Cu post-mordanted fabric had a yellow greenish tone. The light fastness property of the Cu mordanted silk fabric was relatively good, The effect of Al and Fe mordanting on fastness was insignificant. The antibacterial activity of dyed and unmordanted silk fabric was excellent, whereas fabric dyed and mordanted with Undaria pinnatifida extract demonstrated superior ultraviolet protection.