• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2007년도 춘계학술대회논문집
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• pp.257-263
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• 2007

본 논문은 내구성(durability) 및 내오염성(soiling resistance)이 매우 중요한 성질로 인식되는 유통지의 평가방법을 제안하는데 목적이 있다. 즉, 종이의 내구성 및 내오염성의 측정 및 평가에 있어서, 재현성 및 반복성이 우수하고 합리적인 측정방법 및 평가방법을 구축하는데 목적이 있다. 연구목적에 적합한 시료의 준비, 오염물의 조성, 실험장치 및 실험후의 타당한 평가방법 등에 대하여 선행 연구결과를 고찰하였다. 기존 방법의 수정과 새로운 장치의 제작 및 평가방법의 설정을 통해 재현성이 높은 평가방법을 정립하고자 하였다. 유통지의 내구성을 평가하는 방법으로는 습식, 내오염성, 건식 내오염성, 구김기공도, 내세탁성, 잉크 내마모도 등의 항목을 측정하여 개별항목으로 내구성을 가늠하거나, 몇가지항목에 각기 다른 가중치를 부여하여 구한 내구성 지수(durability index)의 개념으로 내구성을 평가하기도 한다. 본 논문에서는 내구성에 영향하는 요소로 강도적 성질요소(strength property value)와 내오염성 요소(artificial soiling value)로 구분하였다. 강도적 성질요소에서는 전통적으로 내구성과 관련이 깊은 것으로 인식되어 온 내절도(folding endurance), 인열강도(tearing resistance) 및 구김기공도(crumpled porosity)를 인쇄하기 전 용지상태에서 측정하여 4:4:2의 가중치를 주어 구하였다. 내오염성 요소는 국가별 기후특성에 따라 연평균 상대습도가 60% 이상인 경우 인쇄 시료를 대상으로하여 습식 내오염성, 건식 내오염성 및 내석검성을 평가한 후 6:3:1의 가중치를 주어 구하였다. 또한 연평균 60% 미만인 국가의 경우 3:6:1의 가중치를 부여하였다. 이렇게 구해진 강도적 성질요소와 내오염성 요소에 있어 강도적 성질요소는 궁극적으로 내오염성 요소에 영향하기 때문에 3:7의 비율로 가중치를 부여하여 최종적으로 내구성 지수를 구하였다. 이때의 점수가 60점 이상이면 내구성 용지로 정의하였다. 본 논문에서는 현장실험을 통하여 시제품을 제조하였다. 상기 설명된 방법으로 내구성 지수를 구한 결과, 일반 유통지 제조방법으로 제조한 경우 내구성 지수가 약 45점이었다. 반면, 새로 개발된 방법에 의한 고내구성용지(durability paper)의 경우 70점 이상을 나타내어 내구성이 향상되었음을 확인할 수 있었다.

• 펄프종이기술
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• 제30권4호
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• pp.18-27
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• 1998

Biopulping is defined as the treatment of wood chips with lignin-degrading fungi prior to pulping. Fungal pretreatment prior to mechanical pulping reduces electrical energy requirements during refining or increases mill throughput, improves paper strength, reduces the pitch content, and reduces the environmental impact of pulping. Our recent work involved scaling up the biopulping process towards the industrial level, investigating both the engineering and economic feasibility. We envision the process to be done in either a chip-pile or silo-based system for which several factors need to be considered: the degree of decontamination, a hospitable environment for the fungus, and the overall process economics. Currently, treatment of the chips with low-pressure steam is sufficient for decontamination and a simple, forced ventilation system maintains the proper temperature, humidity, and moisture conditions, thus promoting uniform growth of the fungus. The pilot-scale trial resulted in the successful treatment of 4 tons of wood chips (dry weight basis) with results comparable to those on a laboratory. Larger, 40-ton trials were also successful, with energy savings and paper properties comparable with the laboratory scale. The overall economics of the process also look very favorable and can result in significant annual savings to the mill. Although the current research has focused on biopulping for mechanical pulping, it is also beneficial for sulfite chemical pulping and some applications to recycled fiber have been investigated.

• 펄프종이기술
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• 제48권2호
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• pp.56-60
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• 2016

Neutral or alkaline papermaking provides many advantages in paper strength and processing conditions. It also provides the opportunity of using calcium carbonate fillers in papermaking. These diverse advantages have made almost all paper machines of printing and writing papers run under neutral and alkaline conditions. On the other hand, linerboard machines, which use recycled papers as a raw material, are running under acid conditions using a rosin sizing system. Because the recycled raw materials used by the linerboard industry contain significant amounts of alkaline papers, the linerboard industry has an interest in the possibility of using the neutral or alkaline papermaking opportunity. In this study, the compatibility of the recycled linerboards under neutral or alkaline papermaking conditions was examined by recycling them under various pH conditions. The sizing degree of the papers recycled under neutral or alkaline was significantly lower than that of acid formed papers indicating that during the neutral or alkaline recycling process the rosin sized papers lost their sizing efficiency. Recycling of acid formed linerboards under neutral or alkaline conditions increased the amount of foam, and the foam contained substantial amount of solid materials derived from the acid sizing systems. Use of cationic polyelectrolytes including PEI and poly-DADMAC improved the sizing degree of the recycled papers under neutral and alkaline conditions. PEI decreased the foam generation as well while poly-DADMAC did not show any reducing effect of the foam. These results suggest that PEI forms coordinate bonds with rosin acid and precipitate them onto the surface of recycled fibers, while the reaction products between poly-DADMAC and rosin acid ions still remain water soluble under neutral or alkaline conditions.

• 펄프종이기술
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• 제47권5호
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• pp.61-67
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• 2015

As the production of palm oil has been increased, the generation of oil palm biomass is also increased and the utilization of the oil palm biomass become more significant topic. One third of the oil palm biomass is empty fruit bunch (EFB) and the other two thirds are oil palm trunks and fronds. However, the effective use of oil palm biomass has not been developed and most of it is discarded near oil palm plants. In this study, we investigated the applicability of EFB to the paperboard mills, as an organic filler. The new organic filler was manufactured in a laboratory by grinding and fractionating dried EFB powder, and its properties were analyzed. The particles of EFB organic filler were larger and more spherical than those of the commercial wood powder. The use of EFB organic filler resulted in a higher bulk of the handsheets with similar trends of physical strength, compared to those made with wood powder. It was concluded that EFB could be used as a raw material to manufacture organic filler for paperboard production.

• 펄프종이기술
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• 제44권1호
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• pp.52-57
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• 2012

In this study, we investigated the possible use of a new inorganic material as alternative filler in the paper industry. The inorganic material is a mineral composed of calcium sulfate, that is generated when manufacturing phosphate fertilizer. The inorganic material was dehydrated by the thermal treatment to $200^{\circ}C$, $500^{\circ}C$, $700^{\circ}C$, and $900^{\circ}C$ to prepare white filler powders. Their basic properties, including color, particle shape, elements, and average particle size were identified. To determine the effect of new inorganic filler on paper's physical properties and strength, handsheets were prepared from HwBKP, SwBKP, and thermal treated inorganic fillers. Handsheets' ISO brightness, opacity, bulk, breaking length, and stiffness were measured. Results confirmed that thermal treated inorganic filler could be beneficial to the bulk and opacity of paper while maintaining higher level of breaking length and stiffness that is achieved using talc.

• 펄프종이기술
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• 제46권3호
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• pp.58-64
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• 2014

Management of organic waste such as livestock manure has been considered as very important issue in terms of the environment. The anaerobic digestion of livestock manure become more attractive treatment method and has been widely applied. In this work, the properties of the residue after the anaerobic digestion of livestock manure was evaluated for providing the basic data to develop new application. The lignin and the ash contents of the residue were much higher than those of other biomass such as wood. The components of the residue were also analyzed with SEM-EDS and Elemental Analyzer. The addition of the residue into the handsheet paper resulted in the higher bulk and he higher air permeability with the loss of the strength properties. The water holding capacity of the handsheet were increased until the 40 % addition of the residue.

• 펄프종이기술
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• 제45권4호
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• pp.65-74
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• 2013

In the manufacture of corrugated box, the fibrous raw materials are mainly consisted of recycled papers, such as KOCC(Korean Old Corrugated Container), kraft sack, and AOCC(American Old Corrugated Container). Among these recycled waste paper, the proportion of KOCC is relatively higher than others in fibrous raw materials. Generally, KOCC shows some poor fiber properties and contains hazardous heavy metal sources. Therefore, it is to evaluate the property of recycled paper sources for eco-friendly corrugated box manufacture. In this study, the physical and mechanical properties of 3 kinds of recycled fibers and their mixed stocks were analyzed. The environmental assessment was also evaluated by analyzing the 4 representative heavy metal contents and evaporation residues in waste papers. As the results, KOCC showed the poorest fiber qualities and had the highest heavy metal contents and evaporation residues among the recycled fibers. Finally, the mechanical strength properties were increased by decreasing KOCC proportion of mixed stock conditions. In addition, the heavy metal contents and evaporation residues were also decreased by increasing recycled AOCC and kraft sack proportion.

• 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.

• 펄프종이기술
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• 제43권2호
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• pp.77-82
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• 2011

The changes in the wet pressing response of old corrugated container(OCC) stock depending on the beating treatment and the addition of polymer aids were investigated with laboratory roll press instrument. Two types of polymer aids, such as high molecular weight polymer with low charge density and low molecular weight polymer with high charge density, were applied in this study. The more beaten OCC stock showed the lower dryness after wet pressing. The addition of polymer aids had great influences on the wet pressing efficiency and paper properties. The dryness after wet pressing was increased by the addition of polymer aids, but the pattern of changes in dryness were different depending on the type of polymer and the properties of stock. The higher molecular weight polymer aids showed the greater increase in the dryness. The properties of paper such as air permeability, bulk, formation, tensile strength were also greatly affected by the addition of polymer aids.

• 한국건축시공학회지
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• 제11권5호
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• pp.419-425
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• 2011

콘크리트의 특성상 상대적으로 작은 인장강도로 인하여 균열에 취약한 성질을 가지고 있다. 따라서 본 연구에서는 무근 콘크리트의 균열저감을 위하여 천연섬유 중 성능이 우수한 것으로 알려진 황마섬유에 대하여 다른 종류의 셀룰로오스 섬유와 비교 검토하여 보았다. 그 결과 황마 섬유의 경우 유동성 측면에서 다른 섬유에 비하여 양호한 결과를 나타내었고, 특히 소성수축 균열 저항성의 경우 혼입량 0.9 및 1.2 kg/$m^3$에서 플레인 대비 50 % 이상의 균열저감 성능을 발휘하였으며, 충격시험의 경우 WF 및 PULP 섬유에서 최종파괴까지 5회의 낙하횟수가 걸리는 반면 황마섬유는 혼입량에 따라 차이가 있지만 10~18회로 우수한 인성적 성질을 발휘하고 있는 것으로 나타났다.