Antimicrobial wrapping paper coated with a ternary blend of carbohydrates (alginate, carboxymethyl cellulose, carrageenan) and grapefruit seed extract

Shankar, Shiv,Rhim, Jong-Whan Elsevier 2018 Carbohydrate Polymers Vol.196 No.-

<P><B>Abstract</B></P> <P>A functional biopolymer-coated paper was prepared by coating a ternary blend of the alginate, carboxymethyl cellulose, and carrageenan with grapefruit seed extract (GSE) for the substitute use of synthetic polymer-coated paper. The microstructure of the surface and cross-section of the coated paper analyzed by field emission scanning electron microscope (FE-SEM) indicated that the biopolymer was compatible with the base paper and filled the pores of the porous fiber to make a smooth-surfaced coating paper. The properties of the biopolymer-coated paper, such as water and oil resistance, water vapor barrier, surface hydrophobicity, and mechanical properties, increased significantly compared with not only the base paper but also commercially used PE-coated paper. The blended biopolymer coating material exhibited strong antibacterial activity against food-borne pathogenic bacteria, <I>Listeria monocytogenes</I> and <I>Escherichia coli</I>, which were destroyed completely within 3 and 9 h, respectively. The packaging test for a minced fish cake packed with the biopolymer-coated paper showed the complete destruction of surface inoculated bacteria in 6–9 days. The biopolymer-coated paper showed a high potential for disposable food packaging applications to increase the shelf-life of packaged food.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A ternary blend of the alginate, carboxymethyl cellulose, and carrageenan with grapefruit seed extract (GSE) was used for coating of paper. </LI> <LI> Water and oil resistance properties of paper increased after coating. </LI> <LI> Water vapor barrier, surface hydrophobicity, and mechanical properties, increased significantly after coating. </LI> <LI> Blended biopolymer coating material exhibited strong antibacterial activity. </LI> <LI> The biopolymer-coated paper showed a high potential for disposable food packaging applications. </LI> </UL> </P>

Effects of poly(butylene adipate-co-terephthalate) coating on the water resistant, mechanical, and antibacterial properties of Kraft paper

Shankar, Shiv,Rhim, Jong-Whan Elsevier 2018 Progress in organic coatings Vol.123 No.-

<P><B>Abstract</B></P> <P>A Kraft paper was coated with PBAT [poly(butylene adipate-co-terephthalate)] with Grapefruit seed extract (GSE) and zinc oxide nanoparticles (ZnONP) using different types of coating bars (No. 20, 30, 40, 50, and 60). The microstructure of the surface of the coated paper showed that the PBAT filled the pores of the porous fibers of the paper to make its surface smooth. The basis weight and thickness of the paper increased after coating. The properties of the coated paper, such as water resistance, water vapor barrier, surface hydrophobicity, and mechanical properties, increased significantly compared with the base paper. The tensile strength of coated paper increased by 40–80 % depending on the coating thickness. The paper coated with PBAT/GSE exhibited potent antibacterial activity against the Gram-positive bacteria (<I>Listeria monocytogenes</I>), while the paper coated with PBAT/ZnONP showed strong antibacterial activity against both Gram-positive (<I>L. monocytogenes</I>) and Gram-negative (<I>Escherichia coli</I>) bacteria.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Kraft paper was coated with PBAT using different types of coating bars. </LI> <LI> The surface of the paper became smooth after coating with PBAT. </LI> <LI> The barrier and mechanical properties of paper improved after coating. </LI> <LI> Paper coated with GSE-ZnONP showed strong antibacterial activity. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

셀룰로오스 나노피브릴을 첨가제로 이용한 도공지의 물성

오규덕,성용주,이학래 한국펄프·종이공학회 2022 펄프.종이기술 Vol.54 No.5

Cellulose nanofibrils (CNF) derived from wood can be used as thickening agents for suspensions or slurries because they form a gel structure by absorbing water and demonstrate an excellent shear thinning behavior. When used as a thickening agent for paper coating, CNF influences the rheological properties and water retention of the coating color, affecting the properties of the coated paper. In this study, the effects of CNF and carboxymethyl cellulose (CMC) on the properties of the coated paper were investigated. In contrast to the CMC-coating, the gloss of the CNF-coating was not improved, even when the coating weight was increased, because of the irregular shrinkage of CNF in the wet coating layer through its gel-formation characteristics. The CNF-coating exhibited a much higher ink and vehicle absorption rate than the CMC-coating. The CNF-coating showed lower variation in the printing density depending on the coat weights. Moreover, the open structure of the CNF-coating improved the absorption rate of the coated paper compared to the CMC-coating, resulting in reduced mottling .

포장용 Sodium Caseinate(CasNa)/Transglutaminase(TG) 코팅지 제조 및 특성 분석

김도완,황지현 한국포장학회 2022 한국포장학회지 Vol.28 No.2

Paper is a promising alternative to petroleum-based plastic materials for sustainable packaging applications. However, paper exhibits poor gas and water vapor barrier properties, which restrict its effective application in the packaging industry. To enhance the properties of papers, sodium caseinate (CasNa)/transglutaminase (TG) coating solutions with various TG contents were prepared and coated on the papers. The chemical and morphological structures, mechanical properties, seal strength, and water vapor barrier properties of the coated papers were thoroughly investigated. The paper properties depended significantly on the chemical and morphological structures. Pristine CasNa and CasNa/TG coating solutions were evenly coated on the paper surfaces, without any cracks. The chemical structure of the CasNa/ TG coated papers was slightly influenced by TG addition, resulting in increased elongation at break and enhanced water barrier properties. To promote the use of CasNa-coated papers in packaging applications, additional investigations must be performed to prevent gas and moisture permeation and enhance the mechanical strength of these papers via chemical reactions and introduction of organic/inorganic composites.

원지의 충전물 함량이 도공지의 접힘 터짐에 미치는 영향

서동일(Dongil Seo),오규덕(Kyu Deok Oh),이학래(Hak Lae Lee),윤혜정(Hye Jung Youn) 한국펄프·종이공학회 2015 펄프.종이기술 Vol.47 No.2

High loading of base paper is regarded as one of reasons to aggravate fold cracking of coated paper. But the relationship between the ash content of base paper and fold cracking of coated paper has not been shown yet. We investigated the effect of ash content in base paper on the fold cracking of coated paper. Handsheets with three different ash contents (19.5-23.5%) were prepared, and double layered coating were applied on the top side of the handsheets. A gravimetric water retention meter (AA-GWR) was employed to fold the paper with a uniform pressure after solid printing on the coated surface. The fold cracking was digitized by calculating the cracked area by means of an image analysis technique. Results suggested that high ash content in the base paper increased the fold cracking of the outer surface of coated papers. In the case of inner surface greater fold crack areas were obtained, and the number of cracks decreased because long and wide cracks were formed. Reduction in tensile strength and thickness appeared to give greater fold cracking for highly loaded papers.

나노 실리카 졸을 이용한 잉크젯 프린팅용 고품질 인쇄용지 도공층의 인쇄적성

김혜진,남산,한규성,황광택,김진호,Kim, Hye-Jin,Nahm, Sahn,Han, Kyu-Sung,Hwang, Kwang-Taek,Kim, Jin-Ho 한국결정성장학회 2019 韓國結晶成長學會誌 Vol.29 No.6

최근 인쇄용지는 단순히 정보 전달의 기능을 넘어서 미적, 예술적 가치가 부가면서 고품질의 인쇄가 가능한 도공지(coated paper)에 대한 시장의 수요가 증가하고 있다. 특히 실사급 고품질의 인쇄가 가능한 잉크젯 프린팅의 도공지는 잉크의 인쇄적성을 향상시키기 위하여 표면에 젖음성(wettability)과 다공성 구조(porous structure)를 갖는 도공층의 역할이 매우 중요하다. 본 연구에서는 나노 실리카 졸 입자에 실란 커플링제로 표면처리하고 수용성 결합제인 폴리비닐알콜(PVA)와 혼합하여 도공액(coating color)를 제조하고 원지(base paper)에 코팅하여 도공층을 제조하였다. 실란 커플링제로 표면처리한 나노 실리카 도공층은 표면처리하지 않은 도공층과 비교하여 균일한 기공 분포 및 평탄한 표면 거칠기를 가지며, 판매용 고급 인화지와 유사한 광택도를 갖는 것을 확인하였다. 특히 잉크의 망점(dot)에 대한 진원도로 평가하는 인쇄적성 평가 결과 실란 커플링제로 표면처리한 도공지는 다층 구조의 도공층을 갖는 판매용 고급 인화지보다 더 우수한 결과를 얻을 수 있었다. 이러한 결과는 실란 커플링제 표면처리를 통하여 나노 실리카 입자의 분산성이 향상되어 우수한 젖음성과 균일한 기공 분포를 갖는 도공층 형성이 가능하였기 때문으로 확인되었다. In recent years, printing paper with a function of information delivery and aesthetic value has attracted a great attention with increasing market demand for coated paper that is capable of high quality printing. The coated paper for inkjet printing with high-quality of photorealistic grades requires the coating layer with a good wettability and porous surface structure in order to improve the printability of ink. In this study, the coated paper was prepared using polyvinyl alcohol (PVA) and surface treated nano silica sol with silane coupling agent. It was confirmed that the coating layer with surface treated nano silica sol showed a uniform pore distribution and flat surface roughness. Glossiness of the prepared printing paper was similar to that of commercial high quality photo paper. Especially, the coated paper with surface treated nano silica sol showed improved printability with excellent roundness of the printed dot of ink. These results indicates that the coating layer with excellent wettability and uniform pore distribution can be formed by using the nano-silica particles with improved dispersibility through the surface treatment of the silane coupling agent.

도공원지의 원료 조성 및 구조에 따른 고평량 도공지의 접힘 터짐

심규정(Kyujeong Sim),윤혜정(Hye Jung Youn),오규덕(Kyudeok Oh),이학래(Hak Lae Lee),여승욱(Seung Uk Yeu),이용민(Yong Min Lee) 한국펄프·종이공학회 2015 펄프.종이기술 Vol.47 No.4

Fold cracking is one of quality troubles of coated papers. In this study, the fold cracking of high grammage (250 g/㎡) coated paper made with the different pulp composition and layer structure of base paper was investigated. The single layered, high grammage base paper was prepared by mixing of hardwood and softwood bleached kraft pulp fibers with the different ratios. The high grammage coated paper showed the higher fold cracking than low grammage coated paper because of the increase in thickness. The increase in the content of softwood pulp fibers reduced the fold cracking in the case of high grammage coated paper. When the creasing process was conducted before folding process, the fold cracking of coated paper decreased. By manufacturing the base paper with multiply structure, the fold cracking of coated paper could be reduced significantly, especially when the BCTMP and OCC were used as a middle layer and the creasing process was carried out. The delamination of layers in base paper affected the fold cracking positively.

원지 특성과 도공 조건이 셀룰로오스 나노피브릴 도공적성에 미치는 영향

박희태(Heetae Park),심규정(Kyujeong Sim),이제곤(Jegon Lee),윤혜정(Hye Jung Youn) 한국펄프·종이공학회 2018 펄프.종이技術 Vol.50 No.5

To investigate the application potential of cellulose nanofibrils (CNF) as barrier coating agent, the coatability of CNF on two different types of base paper (linerboard and woodfree base paper) was evaluated in terms of the coat weight and the surface properties of CNF-coated paper. The consistency of CNF suspension, the applicator type and the addition of a rheology modifier were controlled. The characteristics of a base paper, in particular, the hydrophobicity of a base paper affected the CNF coat weight. Linerboard with low water contact angle showed high coat weight with linear relationship of rod number. On the other hand, woodfree base paper with high water contact angle showed a limit to increase the coat weight. The consistency of CNF suspension did not have a significant effect on the coat weight, but affected the surface roughness of the coated paper. The addition of a rheology modifier into CNF suspension could increased the coat weight a little and improved the surface smoothness. Among diverse factors examined in this study, it was demonstrated that the applicator type is the most important factor to the coat weight. By increasing the rod number and adopting the nip applicator with high gap size, the coat weight of CNF on the base paper could be increased.

이종 폐지 혼합 비율에 따른 종이 품질 및 초지 공정 변화 분석

최도침,류정용,이광섭,김창근,조병욱 한국펄프·종이공학회 2014 펄프.종이技術 Vol.37 No.5

The kind and the mixing ratio of recovered papers would affect the quality of final recycled paper. In thisstudy, effects of the mixing ratio of various domestic recycled papers (old news print (ONP), old corrugatedcontainer (OCC) and coated paper (CP)) on variations in physical properties of paper and its productivitywere investigated. When the mixing ratio of CP grade increased, the freeness (CSF) of recycledpulp was increased while paper strength and white water turbidity was decreased. Paper strength was decreasedas the percentage of OCC was higher than ONP. When ONP was mixed with OCC, no adverseeffect was observed except the increased drainage resistance. It is expected that these results could beutilized as fundamental data to establish regulations for the recovered paper grades according to mixingratios of different kinds of them.

용융염 코팅이 열지에 미치는 영향

임채남,이정민,강승호,정해원,Im, Chae-Nam,Lee, Jungmin,Kang, Seung-Ho,Cheong, Hae-Won 한국전기전자재료학회 2014 전기전자재료학회논문지 Vol.27 No.8

Thermal batteries are primary reserve batteries that use inorganic salt as electrolytes which are inactive at room temperature. The two principal heat sources that have been used in thermal batteries are heat paper and heat pellets. As soon as the heat paper, which is ignited by the initiator, in turn ignites the heat pellets, all the solid electrolytes are melted into excellent ionic conductors. However, the high combustion temperature by heat papers in thermal batteries causes thermal decomposition at the cathode, eventually leading to a thermal runaway. In this paper, we have attempted to prepare $Zr/BaCrO_4$ heat papers coated with KCl molten salt. We have also investigated the effect of a molten salt coating on the heat papers through the thermal characteristics such as calorimetric value, combustion temperature and burning rate. The calorimetric value and combustion temperature of heat papers were reduced with an increase in the molten salt coating. As a result, the molten salt coating on heat papers greatly reduced risk of a thermal runaway and improved the stability of thermal batteries.