• 펄프종이기술
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• 제32권4호
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• pp.49-57
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• 2000

This study was carried out to investigate the effect of the type of base papers containing rice straw-BKP on the properties and printabilities of coated papers. Also, it was intended to evaluate the effect of coated paper prepared with anionic and amphoteric latex based coating color. The results obtained from this study were as follows. The fiber length of rice straw-BKP was observed much shorter than those of the wood pulps(Sw-BKP, Hw-BKP). This has effect on physical properties. Therefore, the results of measured physical properties were much lower than those of wood pulps. Also, physical properties tended to increase slightly with the increase of the mixing ratio of Sw-BKP. Opacity of the base paper containing rice straw-BKP, was higher than that of the wood pulps. As the mixing ratio of Sw-BKP increases the opacity tended to decrease. On the other hand, smoothness and roughness to rice straw-BKP were similar with Sw-BKP and its air permeability was lower than those of wood pulps. The optical properties of coated papers containing rice straw-BKP tended to be similar to those of other base papers. The ink receptivity of coated papers containg rice straw-BKP was higher than those of wood pulps and printing gloss was similar to wood pulps. The mixing ratio of Sw-BKP, the ink receptivity and printing gloss of rice straw-BKP were showed no difference irrespective the mixing ratio of Sw-BKP. Meannwhile, amphoteric latex improved the optical properties and printability of coated papers.

• 펄프종이기술
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• 제39권2호
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• pp.25-30
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• 2007

Recently the use of web offset printing has been increasing, which can provide high print speed, mass production, and high print quality. However, high speed web offset printing has frequently undergone a blistering problem when the printed paper passes through hot air dryers. Blistering occurs in the middle of the base paper or in the coating layer. This paper focused on the blistering occurring in the base paper. In order to elucidate the effect of pigment ratio on blistering, 6 types of coating color were prepared with varying GCC/clay ratios and printability and blistering were investigated focusing on structure changes in the coating layer. When the clay content in the coating layer was increased, surface roughness and surface strength were decreased and paper gloss was increased. In addition, it was found that the coating layer structure with high clay content, which contains lots of discontinuous pores, hindered water vapors to penetrate out and, as a result, blistering occurred.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.154-154
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• 2008

Although the screen printing technology using photosensitive carbon nanotube (CNT) paste has many advantages such as low cost, simple process, uniform emission, and capability of mass production, the CNT paste needs to be improved further in CNT dispersion, printability, adhesion, electrical conductivity, population of CNT emitters, etc. Ball milling has been frequently employed to prepare the CNT paste as ball milling can mix its ingredients very well and easily cut the long, entangled CNTs. This study carried out a parametric approach to fabricating the CNT paste in terms of low-energy ball milling and a paste composition. Field emission properties of the CNT paste was characterized with CNT dispersion and electrical conductivity which were measured by a UV-Vis spectrophotometer and a 4-point probe method, respectively. Main variables in formulating the CNT paste include a length of milling time, and amounts of CNTs and conductive inorganic fillers. In particular, we varied not only the contents of conductive fillers but also used two different sizes of filler particles of ${\mu}m$ and nm ranges. Among many variations of conductive fillers, the best field emission characteristics occurred at the 5 wt% fillers with the mixing ratio of 3:1 for ${\mu}m$-and nm-sizes. The amount and size of fillers has a great effect on the morphology, processing stability, and field emission characteristics of CNT emitter dots. The addition a small amount of nm-size fillers considerably improved the field emission characteristics of the photosensitive CNT paste.

• 한국의류산업학회지
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• 제15권5호
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• pp.808-814
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• 2013

In this study, The mixture of three kinds of pre-treatment agents, Carboxymethyl cellulose sodium salt(CMC), Sodium alginate and Dextrin, have been prepared for the better coloration of digital textile printing. To get sharpness of outline during digital printing process, the optimal formulation is the CMC and Sodium alginate mixture 1:1 ratio by volume. Cyan, Yellow, and Black colours are excellent on the Sodium alginate mixtures. But, Magenta is excellent in the CMC and Dextrin mixture. Sharpness and printability are closely related to viscosity of the mixture. The most optimal sharpness of outline achieved with a consideration of coloring, and field operations account for production when the viscosity of the mixed pre-treatment agent approximately is 10~13 cSt. Change in shade and staining of wash fastness for all the treated samples with the mixtures rated 4-5 grade. Both dry rubbing fastness to shade change and staining are good in the treated samples, whereas wet rubbing fastness rated 2-3 grade. To improve wet rubbing fastness, the Sodium alginate and Dextrine mixture, which rated 3-4 grade for Black color, is applicable. With exception of 3 rating to black color, Light fastness is 4 rating for the remaining three colors in the regardless of treatment condition and mixing of the pre-treatment agent. Dry cleaning fastness of all samples are also 4-5 rating.

• Elastomers and Composites
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• 제39권1호
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• pp.3-11
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• 2004

플라즈마 표면처리는 표면 관능기 표면 활성도 등을 증가시켜 촉매적 선택성, 염색성 및 다양한 소재의 접착력을 증가시켜주는데 큰 역할을 담당한다. 본 연구에서는 dielectric barrier discharge (DBD)를 이용한 상압 플라즈마 토치로 ethylene-vinyl acetate (EVA)의 표면을 처리하였다. 이때 사용된 가스는 아르곤, 공기, 및 산소를 이용하였으며, 표면처리에 따른 EVA의 표면 특성을 제타전위와 표면자유에너지를 이용하여 관찰하였다. 그 결과, 상압 플라즈마 표면처리에 따른 EVA의 표면 관능기는 접착 에너지 ($G_{IC}$)와 비례관계를 가지며 증가하는 것을 확인하였다. 특히, 상압 플라즈마 표면처리 공정은 EVA와 polyurethane (PU) 계면의 접착력을 크게 증가시켜 주는 것을 확인하였다.

• 한국전기전자재료학회논문지
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• 제21권9호
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• pp.835-843
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• 2008

We have fabricated the source-drain electrodes for OTFTs by screen printing method and manufactured Ag pastes as conductive paste. To obtain excellent conductivity and screen-printability of Ag pastes, the dispersion characteristics of Ag pastes prepared from two types of acryl resins with different molecular structures and Ag powder treated with caprylic acid, triethanol amine and dodecane thiol as surfactant respectively were investigated. The Ag pastes containing Ag powder treated with dodecane thiol having thiol as anchor group or AA4123 with carboxyl group(COOH) of hydrophilic group as binder resin exhibited excellent dispersity. But, Ag pastes(CA-41, TA-41, DT-41) prepared from AA4123 fabricated the insulating layer since the strong interaction between surface of Ag powder and carboxyl group(COOH) of AA4123 interfered with the formation of conduction path among Ag powders. The viscosity behavior of Ag pastes exhibited shear-thinning flow in the high shear rate range and the pastes with bad dispersion characteristic demonstrated higher shear-thinning index than those with good dispersity due to the weak flocculated network structure. The output curve of OTFT device with a channel length of 107 ${\mu}m$ using screen-printed S-D electrodes from DT-30 showed good saturation behavior and no significant contact resistance. And this device exhibited a saturation mobility of $4.0{\times}10^{-3}$ $cm^2/Vs$, on/off current ratio of about $10^5$ and a threshold voltage of about 0.7 V.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.311-316
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• 2006

The role of short fibre pulp - Mixed Harwood, Eucalyptus, Aspen, Birch, etc for the manufacture of different grades of paper is very well recognized. At the same time, lots of efforts are in progress to maximize the advantages while preserving their own special property. Bleached Acacia Kraft Pulp (BAKP) is comparatively new entry but gained quick recognition. BAKP was introduced to the world market by South East Asian suppliers in the late 1990's. This paper discusses in detail the role and opportunities of use of short fibre pulps. A logical technical comparison has been made between BAKP and another short fibre grades. BAKP being a short, thin-walled fibre shows several similarities with Eucalyptus pulp in terms of good bulk and stiffness. Refining energy and strength properties are very similar, but the shorter fibres and thinner cell walls give an outstanding opacity and formation compared to other commercial short fibre pulps. The collapsed and band-shaped nature gives a matchless smoothness, enabling less calendaring and exceptional printing properties. BAKP is shown to give several advantages to fine paper manufactures, compared with a number of established short fibre pulps such as Brazilian and Chilean Eucalyptus, Canadian Aspen and Indonesian Mixed Hardwood. It is important to consider refining and calendaring conditions to achieve optimum performance. For outer layers of multiply board, Acacia gives excellent coverage due to its high opacity and uniform fibre distribution. Its low roughness property gives improved printability. For tissue products, Acacia gives unique property of superior softness both in terms of hand feel and bulk softness. The high fibre population gives an impression of much higher quality due to the higher opacity and good formation.

• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.388-395
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• 2018

Significant efforts have been applied toward fabricating three-dimensional (3D) scaffolds using 3D-bioprinting tissue engineering techniques. Gelatin has been used in 3D-bioprinting to produce designed 3D scaffolds; however, gelatin has a poor printability and is not useful for fabricating desired 3D scaffolds using 3D-bioprinting. In this study, we fabricated pore size controlled 3D gelatin scaffolds with two step 3D-bioprinting approach: a low-temperature ($-10^{\circ}C$) freezing step and a crosslinking process. The scaffold was crosslinked with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). The pore sizes of the produced 3D gelatin scaffolds were approximately 30% smaller than the sizes of the designed pore sizes. The surface morphologies and pore sizes of the 3D gelatin scaffolds were confirmed and measured using scanning electron microscopy (SEM). Human dermal fibroblasts (HDFs) were cultured on a 3D gelatin scaffold to evaluate the effect of the 3D gelatin scaffold pore size on the cell proliferation. After 14 days of culture, HDFs proliferation throughout the 3D gelatin scaffolds prepared with more than $580{\mu}m$ pore size was approximately 14% higher than proliferation throughout the 3D gelatin scaffold prepared with a $435{\mu}m$ pore size. These results suggested that control over the 3D gelatin scaffold pore size is important for tissue engineering scaffolds.

• 한국포장학회지
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• 제24권2호
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• pp.49-56
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• 2018

인쇄형 TTI의 잉크로 천연물질인 안토시아닌의 적용 가능성을 확인하기 위해 실제 인쇄형 TTI를 제작하여 색 변화를 확인하였다. 안토시아닌은 반응속도가 느려 TTI에 적용이 어렵다. 이를 해결하기 위해 ${\beta}$-글루코시다아제를 이용하여 안토시아닌의 탈당화를 유도하여 보다 불안정한 안토시아니딘 잉크를 제작하였다. 그리고 인쇄형 TTI로 제작이 적합한지 확인하기 위해 인쇄적성을 확인하고 적용가능한 식품군을 탐색하였다. 실험결과, 인쇄적성의 경우, 틱소트로피의 히스테리시스 성질을 나타내어 인쇄적성이 적합한 것으로 확인되었다. 색 변화의 경우, 같은 온도와 pH 조건 하에서 안토시아닌 TTI의 색 변화 속도보다 안토시아니딘 TTI의 색 변화속도가 빠른 것을 확인할 수 있었다. 또한, 안토시아닌 인쇄형 TTI의 활성화 에너지는 65.21 kJ/mol, 안토시아니딘 인쇄형 TTI의 활성화 에너지는 86.92 kJ/mol로 확인되었다. 이는 ${\beta}$-글루코시다아제를 처리한 안토시아닌의 탈당화가 안토시아닌의 반응속도를 빠르게 할 뿐만 아니라, 활성화 에너지도 증가시킨 것으로 사료된다. TTI의 활성화 에너지와 식품의 활성화 에너지를 비교한 결과, 안토시아닌 TTI는 냉장 육제품에 한정적으로 적용 가능하였다. 반면에 안토시아니딘 TTI는 냉장 육제품과 냉장 어류에 적용 가능하였다. 하지만, 안토시아닌 TTI는 색 변화 종말점에 도달하는 시간이 길기 때문에 냉장 육제품에 적용이 어려울 것으로 사료된다. 반면 안토시아니딘 TTI의 경우, 색 변화 종말점에 도달하는 시간이 짧기 때문에 냉장 육제품과 냉장 어류에 적용이 가능할 것으로 사료된다.

• 패션비즈니스
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• 제15권5호
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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.