• 펄프종이기술
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• 제46권2호
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• pp.16-21
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• 2014

Characteristics of coating color penetration into paper were elucidated using various types of pulps and pigments. A commercial paper, KP and TMP handsheets were used for base paper. Clay and GCC were used as coating pigment. Laboratory rod draw down coater was used for coating application. Coating color penetration was evaluated by measuring the roughness of surface and back side of a coating layer. The results of coating roughness showed that clay was much better than GCC as a coating pigment. In case of pulp type, KP base paper was more effective than TMP base paper to reduce coating penetration.

• 펄프종이기술
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• 제43권3호
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• pp.121-127
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• 2011

This study used two types of rheology modifiers including an alkali-swellable emulsion (ASE) and an surface-adhesion emulsion (SAE) to elucidate their effects on high shear viscosity and dynamic penetration behavior among the flow properties of high solids coating. Since rheology under high shear and dynamic penetration behavior significantly affect the quality of coated paper in case of high solids coating, it is very important to examine the variations in rheology of high solids coating color by rheology modifier. It was found that the high solids coating color prepared with the SAE type showed superior dynamic penetration behavior and high shear viscosity than that with the ASE type rheology modifier.

• 한국전기전자재료학회논문지
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• 제29권4호
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• pp.247-249
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• 2016

In this study, we investigated the color change of the normal light gray granite as the high value color granite. By coating the metal catalyst liquid on the surface of granite stone, the metal particles were penetrated into the granite and the color of granite was changed permanently through the annealing treatment. To increase penetration depth into the granite, we used DC (direct current) bias. Two kinds of bias were used such as DC bias and pulse DC bias. And the penetration time was changed as 30 and 60 min. In all cases, the color granite were successfully obtained. Regardless of the catalyst reaction time, the penetration depth was increased by using the bias treatment. We obtained a penetration depth of 21 mm with the DC pulse bias during 60 min.

• 펄프종이기술
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• 제39권2호
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• pp.17-24
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• 2007

PEA(Print Evenness Analyzer) Module can be utilized as a tool to evaluate print mottle. The tester is de-signed to measure the uniformity of liquid penetration into paper at very short contact time. To evaluate effects of base paper properties on print mottle, the experiments were performed with 3 types of base pa-per whose sizing degree, roughness and porosity were varied. Coated papers were produced with high solid coating color (70%) and low solid coating color (67%). Uniformity of water absorption into base paper and coated paper was measured with PEA. It was found that, in order to minimize print mottle, base paper shall be produced with a high sizing degree and low roughness and the concentration of coating color shall be kept as high as possible, providing that it has proper rheology properties for coating process.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.485-488
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• 2006

Surface roughening which is occurred by interaction between base paper and water in coating color deteriorates surface properties of coated paper. In this study, the effect of calendering variables on surface roughening and the relationship between hot calendering and water penetration depth were investigated. BCTMP handsheets were calendered at the various conditions of temperature and linear load, and its PPS roughness was measured before and after moistening to evaluate surface roughening. To determine water penetration depth, thickness was measured from the cross sectional images of sheet which were obtained using CLSM technique. High pressure calendering was beneficial to reduce surface roughness before coating but its smoothening effect was mostly lost by contact with water. On the contrary, sheet calendered at the highest temperature showed the lowest roughening. High temperature calendering allowed the smallest penetration of water into fiber network because of sufficient deformation and densification in top side of z-direction of sheet. Consequently, hot calendering could be the effective way to reduce surface roughening and unevenness of paper surface.

• 한국염색가공학회지
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• 제17권6호
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• pp.27-35
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• 2005

Conventional pad- dry-cure(thermo-fixation) process usually produces functional performance on both sides of a fabric. UV curing technique was applied to impart water- and oil-repellent finish effective only on the face of a PET knitted fabric. The preferential one-side coating, by virtue of the limited penetration of UV light, was achieved by W curing after padding of a fluorocarbon agent without special coating or printing equipments. The difference in the functional property of face and back sides was examined by measuring water and oil repellency at each side of the treated fabric. The influence of pre/post-irradiation dose and agent concentration on the performance of the finished fabrics were investigated. While increase in both resin concentration and post-irradiation did not have significant effect on the finish, UV pre-irradiation of PET fabrics caused remarkable influence presumably due to appropriate surface modification of PET fabrics required for facile wetting of the resin. The dimensional stability and color change of the UV cured fabrics measured by FAST and reflectance spectrophotometry showed significantly decreased color difference and increased percent extension compared with the samples pre-irradiated without agent application.

• 펄프종이기술
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• 제34권3호
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• pp.53-58
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• 2002

This paper was performed to investigate the effect of pore structure on ink residual behavior. To prepare different coating structures as substrates against inks, fine, medium and coarse calcium carbonate were used in the coating color. It is well known ink properties can affect to print qualities. After printing on the coated paper, ink layer can consider as third structure addition to paper and coating layer. To compare effect of ink properties on the surface structure and print qualities, several properties of ink were also adopted as raw material. Particle size of pigment effect on gloss evaluation of coated paper increased with calendering. It was shown that ink transfer rate increased as surface of the sample was smooth. The ink contained low viscosity resin evaluated more print gloss. Finer pigment particle size, smaller pore size and higher porosity. Pore volume of coated paper was slightly decreased with printing as the coating was prepared with the finest particle size. However, it founded that ink resin could not affect on pore volume and distribution of printed paper

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2008년도 제33회 펄프종이기술 국제세미나
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• pp.47-70
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• 2008

Cost efficiency is today the primary requirement in the paper and board industry. This has led therefore, to a greater preponderance of products with specifically designed functionality to take account of current industry needs. Continually increasing machine coating speeds together with these new coating colour components have put more emphasis on the importance of the correct rheology and water retention of the coating colours to achieve good runnability and end product quality. In the coating process, some penetration of the aqueous phase, to the base paper or board must occur to anchor the pre-coating to the base or the topcoat to the pre-coat. The aqueous phase acts as a vehicle not only for the binder, but also for the other components. If this water or material penetration is not controlled, there will be excessive material shift from the coating colour to the base, before immobilization of the coating colour will stop this migration. This can result in poor machine runnability, unstable system and uneven coating layer, impacting print quality. The performance of rheology modifiers or thickeners on the coating color have tended to be evaluated by the term, "water retention". This simple term is not sufficient to explain their performance changes during coating. In this paper we are introducing a new concept of "material retention", which takes note of the total composition of the coating colour material and therefore goes beyond the concept of only water retention. Controlled material retention leads to a more uniform z-directional distribution of coating colour components. The changes that can be made to z-directional uniformity will have positive effects on print quality as measured by surface strength, ink setting properties, print gloss, mottling tendency. Optical properties, such as light scattering, whiteness and light fastness delivery should also be improved. Additionally, controlled material retention minimizes changes to the coating colour with time in re-circulation giving less fluctuation in quality in the machine direction since it more closely resembles fresh coating for longer periods. Use of the material retention concept enables paper and board producers to have more stable runnability (i.e. lower process costs), improved end product quality (i.e. better performance of used chemicals) and/or optimized use of coating colour components (i.e. lower total formulation cost)

• 한국식품과학회지
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• 제31권3호
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• pp.771-777
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• 1999

CSLM 기술을 이용하여 Salmonella enteritidis에 의한 계란 오염 과정을 관찰하여 난막의 3중막 구조, cuticle 층 그리고 5가지 필름 피복의 침투 방어효과를 조사하였다. 난막을 구성하는 fiber의 지름은 각각 outer membrane $1.5{\sim}7.2\;{\mu}m$, inner membrane $0.8{\sim}2.0\;{\mu}m$이었고, limiting membrane을 구성하는 입자의 지름은 $0.1{\sim}1.4\;{\mu}m$이었으며, 두께는 각각 평균 10.0, 3.5, $3.6\;{\mu}m$이었다. 난각과 접해 있는 outer membrane은 다음 층인 inner membrane과 부분적으로 중첩되어있고, limiting membrane의 입자들은 매우 밀집되어 inner membrane과 중첩된 상태로 존재하였다. Cuticle층은 전체 계란 표면적 중 $40{\sim}80%$ 를 덮고 있었으며, 두께는 평균 $6.0\;{\mu}m$이었고 피복 필름들의 평균 두께는 자각 mineral oil $5.0\;{\mu}m$, dextrin $3.6\;{\mu}m$, gelatin $3.9\;{\mu}m$, starch $2.5\;{\mu}m$, chitosan $2.2\;{\mu}m$이었다. 필름 피복에 의한 Salmonella enteritidis 생육 억제효과를 관찰한 결과, chitosan이 가장 효과적이었다. 그리고 trisodium phosphate (TSP), cetylpyridinium chloride (CPC) 처리, 5종의 필름 피복 처리와 무처리한 계란표면에 Salmonella enteritidis를 접종한 후 내부 전이 과정을 CSLM을 이용하여 다색영상화(multi-color imaging)와 시간당 투과 균수에 대한 plate count로 비교한 결과, 난각이나 3중막 구조의 난막보다는 cuticle 층이 Salmonella균의 오염을 차단하는데 결정적인 역할을 하는 것으로 나타났으며, chitosan 피복이 cuticle 층과 비슷한 효과를 보였다. 따라서 피복 필름중에서 chitosan이 최외부 방어막인 cuticle층이 결손된 난각 부위를 피복하는데 가장 적합할 것으로 사료된다.

• 한국안광학회지
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• 제4권2호
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• pp.123-128
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• 1999

25mol% CoO가 고용된 $Al_2O_3$계 코팅박막을 졸-겔법으로 제조하고 열처리온도의 변화와 코팅 횟수에 따른 광투과 스펙트럼과 표면반사율과 색상의 변화를 분석 연구하였으며 그 결과는 다음과 같다. $Al_2O_3$-CoO계 박막의 UV-Visible 영역에서의 분광투과율은 약 600nm를 최고 정점으로 하여 파장의 감소와 함께 감소하였으며, 평균 분광투과율은 $300^{\circ}C$(61%), $400^{\circ}C$(55%), $550^{\circ}C$(53%)로 열처리온도가 증가할 수록 광투과율이 감소하는 경향을 보였다. $550^{\circ}C$에서 열처리한 $Al_2O_3$-CoO계 박막의 1~5회 범위의 코팅 횟수에 따른 UV-Visible 영역에서의 분광투과율은 코팅 횟수의 증가와 함께 2차 함수 곡선을 따라 급속히 감소하였다. Indentor penetration method에 의한 $Al_2O_3$-CoO계 박막의 microhardness는 $300^{\circ}C$($370{\times}10^7N/m^2$), $400^{\circ}C$($405{\times}10^7N/m^2$), $550^{\circ}C$($417{\times}10^7N/m^2$)로 열처리 온도의 증가와 함께 증가하였다. 박막의 표면반사광의 스펙트럼은 열처리 온도의 증가에 따라 반사용은 낮아지며, Db값이 20~30 범위에서 높은 값으로 전이하여 황색의 심도가 깊어졌다. 박막의 코팅 횟수에 따라서는 1회(600nm), 2회(560nm), 4회(530nm)로 낮아지다가 5회 (575nm)로 다시 높아지는 결과를 보였으며 yellow에서 greenish-yellow로 변화하다가 Db가 약 50에 달하는 deep yellow로 전이하였다. 명도는 1회(69.77), 2회(68.64), 3회(63.14), 4회 (64.94), 5회(60.42)로 코팅 횟수의 증가에 따라 점차 낮아지는 경향을 보였다.