• 펄프종이기술
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• 제33권3호
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• pp.24-28
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• 2001

The utilization of wastepaper as a papermaking raw material is everlastingly required for the environmental protection of earth. However the recycling of wastepaper for this purpose cause another problem such as the increasing of the load of wastewater treatment, lower strength properties of paper, and poor printability, etc. The interest in the development of the environmentally friendly deinking technology is increased continuously. Thus, our research team have tried to apply the ozone to the deinking of white ledger and ONP, and obtained the positive results which can be considered as an alternative method for the conventional deinking method. The purpose of this study is to investigate the mechanism of ozone deinking. Styrene acrylate and polystyrene were treated with ozone and measured the change of molecular weight with the GPC. The molecular weight distribution obtained with GPC showed only slight increase by the ozone treatment, and gel formation by the polymerization was observed. Therefore the removal of ink particles with ozone treatment seems to be facilitated by the increase of the brittleness and decrease of adhesive property.

• 펄프종이기술
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• 제47권1호
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• pp.52-58
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• 2015

White ledger usually includes white office paper, computer paper, and copy machine paper. Because these grades need high optical properties, fluorescent whitening agents (FWAs) are widely used in the papermaking process. FWAs are the most powerful and effective chemical used to obtain high CIE whiteness and ISO brightness in papers. The rising demand for white or ultra-white papers has increased the use of FWAs. However, FWAs used in white ledger can restrict its use, even though white ledger is widely used as a raw material in paperboard mills. Therefore, it is necessary to develop methods to control FWAs from white ledger to increase its use in paperboard mills. In this study, the behaviors of disulpho fluorescent whitening agent (D-FWA), tetrasulpo fluorescent whitening agent (T-FWA), and hexasulpho fluorescent whitening agent (H-FWA) during the recycling process were identified as a first step to remove FWAs from white ledger. We prepared four types of papers (dyed with D-FWA, T-FWA, and H-FWA), disintegrated these papers, and made handsheets. This recycling process was carried out three times in a laboratory. After each round of recycling, the hand-sheets' CIE whiteness and fluorescence index were measured, and the distribution of FWAs in the Z-direction was observed using CLSM images. FWA reductions in the model papers were calculated using fluorescence indices as a function of the number of recycling. FWAs in handsheets containing T-FWA and H-FWA decreased linearly as a function of the number of recycling, but D-FWA did not show a significant reduction in the fluorescence index after recycling. T-FWA and H-FWA showed similar distributions of D-FWA after recycling. Therefore, as much T-FWA and H-FWA as possible must be detached in the early processes of papermaking at paperboard mills.

• 공업화학
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• 제9권7호
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• pp.961-967
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• 1998

종이제조에 있어서 종이의 광학적 성질 및 인쇄적성을 개선하기 위하여 여러 종류의 충전제가 사용되고 있다. 본 연구는 신문용지 제조에 있어서 여러 종류의 충전제, 즉 경질탄산칼슘(PCC), 중질탄산칼슘(GCC), 그리고 혼합된 충전제(PCC+미세활석(MVP) 또는 활석(talc), GCC+MVP 또는 talc))를 종이에 충전시켰을 때 종이의 여러 물성에 미치는 영향을 검토하였다. 얻어진 결과를 요약하면 다음과 같다. 1) 충전제를 지료전건중량당 5% 처리시 동일 처리조건하에서의 충전제 보류율은 PCC 처리시 GCC 처리시보다 16.8% 정도 높게 나타났으며, PCC 및 GCC를 처리했을 때 모두, 배합한 충전제의 입자경이 커질수록($PCC{\leq}GCC<MVP<talc$) 보류율이 증가하는 경향을 나타내었다. 2) PCC 처리시 무처리보다(92.2%) 대비 2.3% 이상의 비교적 높은 불투명도 개선효과를 나타내었으며, 배합한 충전제의 평균 입자경이 클수록 불투명도가 감소하는 경향을 나타내었다. 3) PCC 단독 처리시 GCC 단독 처리시보다 소폭의 인열강도 하락을 나타내었으며 20% 배합처리한 충전제의 평균 입자경이 커질수록 인열강도가 증가하는 경향을 나타내었다. 4) PCC 단독처리시 비교적 높은 인장강도를 나타내었으며, 다른 충전제와 혼합처리시 인장강도의 하락폭은 GCC 처리쪽이 적은 것으로 나타났다. 5) PCC를 처리하였을 경우, 배합한 충전제의 입자경이 커질수록 ($PCC{\leq}GCC<MVP<talc$) 파열강도는 직선적으로 감소하였다. 6) 충전제를 처리하였을때 무처리보다 비교적 우수한 인쇄적성 효과를 나타내었다.

• 대한화학회지
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• 제47권3호
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• pp.220-228
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• 2003

본 연구는 섬유 교질-현탁액내 PAE 고분자 전해질의 흡착성향과 Lanumuir 및 Freundlich식 흡착 평형에 대한 열역학적 특성을 규명하기 위하여 수행되었다. 섬유의 계면동전위적 특성은 흐름-전기적 방법의 제타전위 측정에 의해 분석되었고, PAE 고분자 흡착량은 고분자 전해질용액의 PCD 적정을 통해 측정되었다. PAE 고분자 내첨은 지료의 제타전위에 크게 영향을 미쳤으며 내첨 초기에는 제타전위 상승 효과가 크게 나타났지만 시간의 경과와 함께 전하 감쇄현상을 나타내었다. PAE 고분자는 저온 또는 상온에서 준-Langmuir 흡착 거동을 보여주었으나 온도가 증가하면서 Freundlich 지수항(v)이 비례적으로 높아지는 결과를 나타내었다. PAE 고분자의 Gibbs 흡착 자유에너지로부터 산출한 트레인 수$(N_{seg})$는 상온에서 약 7~8의 범위로 나타났고 고분자 고리의 노출반경은 약 215 nm로서 $10^{\circ}C$ 온도상승에 대해 점차 9%씩 증가하였다. 지료 내 PAE 고분자의 흡착 엔탈피는 -27~-29 kJ/mol이며 저에너지 물리흡착임이 규명되었다.

• 보존과학회지
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• 제34권6호
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• pp.517-524
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• 2018

본 연구는 닥나무의 삼단면 관찰을 통하여 공통된 해부학적 특성을 가지는지 확인하고 닥나무 인피섬유의 섬유장 폭, 내강폭과 같은 형태학적 특징과 화학적 특징을 통해 펄프, 제지공정에 영향을 미칠 수 있는 인자들을 분석하였다. 닥나무는 환공재, 반환공재이며 대도관이 고립관공으로 방사상배열이다. 접선단면 방사조직은 1~3열이고 나선비후가 관찰되어져 공통적으로 동일한 해부학적 특성이 나타났다. 인피섬유의 형태학적 특징으로는 섬유장 6.58~9.01 mm, 섬유폭 $15.85{\sim}27.80{\mu}m$, 내강폭 $4.50{\sim}12.54{\mu}m$로 나타났다. 펄프, 제지공정에 중요한 특성으로 여겨지는 runkel ratio, slenderness ratio 등을 고려했을 때 강원도 D시료가 가장 적합하였다. 인피섬유의 화학적 특성으로 경상도 C시료가 낮은 추출물 함량과 높은 셀룰로오스 함량을 가지는 것을 확인하였다. 섬유의 형태학, 화학적 특성은 한지 제조 후 품질을 결정하는 주요 인자의 기초자료로 활용될 것이다.

• 펄프종이기술
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• 제47권4호
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• pp.160-167
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• 2015

The reduction of energy consumption in papermaking process has been considered as one of the major issue in the paper technology. The energy efficiency of paper mill becomes more significant for the mill which manufacture the board grade products such as linerboard with recycled paper such as OCC. The application of lignocellulose spacer to the board grade paper stock would be the feasible solution by increasing the paper bulk and the drying efficiency. The major defects originated from the application of the lignocellulose spacer could be the loss of strength properties. In this study, the ways for improving the strength properties of the spacer-added linerboard were suggested and evaluated. The effects of the addition of various types polyelectrolytes were tested and the different methods of polyelectrolytes were applied for finding the efficient way. The pretreatments of lignocellulose spacer with the polyelectrolytes during wood spacer hydration resulted in the higher strength properties than the typical application method such as the addition to the mixed stock. Multilayer treatments of the spacer with polyelectrolytes were also evaluated and leaded to the higher strength properties with the similar bulk improvement.

• 펄프종이기술
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• 제47권4호
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• pp.54-59
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• 2015

In this study, effects of kneading concentration on characteristics of hardwood bleached kraft pulp (HwBKP) fibers were elucidated. A laboratory two-shaft kneader was utilized for kneading. Kneading concentration was varied in the range of 15-30% (w/w) and the number of kneading treatment was adjusted between 0 and 6 passes. It was found that kneading concentration influenced fiber characteristics. At 15% of pulp concentration, fiber length slightly increased with increasing the number of kneading passes, while other morphological properties such as fiber width and curl decreased: fiber straightening occurred. In addition, the increase in WRV and the decrease in CSF were the largest at 15% kneading concentration, meanings that fibrillation mainly occurred. In contrast, at higher kneading concentration exceeding 20%, fiber deformation like curl was mainly occurred. Also, at kneading concentration of 20% and 30%, fiber length decreased with the number of kneading passes while other morphological properties such as fiber width, and WRV increased. Severe fiber entanglement was found at 30% kneading, which shall be removed during papermaking.

• 펄프종이기술
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• 제41권1호
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• pp.24-29
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• 2009

The use of fluorescent whitening agents (FWAs) increases as the demand for the whiter and brighter printing papers increases. FWAs are used as internal and surface treatment chemicals. FWAs that are not used properly in the papermaking process, however, remain in the process water and may demage the paper quality and processes. In this study, a new idea to eliminate FWAs from the process water, consisted of the floc formation of FWAs with cationic chemicals, such as cationic polyelectrolytes and alum, and the removal of the floc by screening or sedimentation, was proposed. Flocculation of FWAs, that is the first step to remove FWAs from the process water, was investigated using turbidity and particle size measurement. Relationship between turbidity and particle size showed that the turbidity could reflect the particle size change of FWA flocs and was proper for the evaluation of flocculation phenomena. Poly-DADMAC was more efficient than PEI to induce the flocculation of FWAs. Alum was effective chemical for the flocculation and sedimentation of FWAs.

• 펄프종이기술
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• 제33권2호
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• pp.32-40
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• 2001

It is desirable to reduce the amounts of fresh water and reuse the recycled water in papermaking process. In an attempt to improve the efficiency of recycling water refining treatment and to enhance the productivity of OCC recycling mill, up flow anaerobic sludge blanket(UASB) reactor was developed and introduced to Korea recently. In order to maximize the operating efficiency and minimize the adverse side effects it is imperative to estimate and evaluate the total effects of new system, UASB on the whole OCC recycling process. This study was carried out with a view to investigate the effects of the high temperature and alkalinity of process water on the quality ad productivity of testliner of OCC recycling mill which is equipped with UASB reactor and almost closed. Another object of this study was searching for the best available use of UASB treated process water. The results were as follows; Reuse of UASB treated water characterized with high temp and alkalinity was useful to improve the strength and drainage properties of recycled OCC owing to its good points of promoting OCC disintegration and reducing the calcium hardness of process water. However, it might not be avoidable to induce the increase of dissolved solids in process water in accordance with direct introducing of UASB treated water into the former stage of OCC stock preparation. So it would be advisable to adopt the UASB treated water in the stage of clean, screened OCC stock.

• 펄프종이기술
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• 제46권1호
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• pp.56-64
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• 2014

The applicability of oil palm EFB(Empty Fiber Bunch) to the papermaking process as a functional organic filler was investigated in this study. Since the EFB has similar chemical composition to the lignocellulose materials such as wood fiber, the fines of EFB was applied to the handsheet paper as an alternative to wood powder which were used as an organic filler to improve water removal efficiency and bulk. The experiments showed that the EFB fines resulted in the higher water removal efficiency at the wet pressing process and leaded to the higher bulk than those of wood powder. In case of 10 % addition of organic filler, the strength properties were not significantly changed. Those results suggested that the EFB could be used as a new organic filler for improving water removal efficiency and bulk property.