• 펄프종이기술
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• 제31권2호
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• pp.25-33
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• 1999

A great difference in drainage time was observed from the recycled stocks between corrugated container board and its component papers, liner and medium paper. It could be assumed that the different drainage property should be caused from a starch adhesive present in the corrugated board. Thus, three types of starch such as dried Stein-Hall adhesive, cooked starch solution, and its dried film were added to linerboard stock in order to investigate the mechanism of drainage reduction. The water-swollen starch particles derived from Stein-Hall adhesive were drastically deteriorated the drainage time, even though the amount of starch is very small (2% or below). The drainage time of OCC was improved by 25% when amylase was used a new biological treatment. The results from the lab and mill test showed that the starch-degradable enzymatic treatment improves the drainage property as well as the reduction of calcium hardness.

• 펄프종이기술
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• 제31권1호
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• pp.10-16
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• 1999

Air froth flotation was applied to OCC recycling process as a new pulp fractionation method and the effects of strength and drainage properties of testliner were also investigated. Fines including inks, stickies, and inorganic substances in OCC stock furnish were efficiently separated by the flotation. After the flotation, selective enzymatic treatment on the flotation reject was separately preformed, and then, the refined long fiber(flotation accept) portion was combined again with the fines(flotation reject) fraction for papermaking. This combination process was found to be effective in improving strength and drainage properties of testliner based on 100% OCC.

• 펄프종이기술
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• 제30권3호
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• pp.22-28
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• 1998

The blended enzymes were applied for OCC recycling system to use the selective activities of various enzymes. Cellulase and hemicellulase were very effective in terms of the strength of recycled paper The effect of the addition of amylase on the drainage improvement indicates that the starch, which was used as an adhesive of corrugated container, deteriorates the drainage property in OCC recycling system. From the result of Scheffe's analysis, the combination of cellulase and amylase (50/50, w/w) were the most effective in improving the drainage properties with increased strength.

• 펄프종이기술
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• 제32권4호
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• pp.18-26
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• 2000

In order to investigate the influencing factors in flotation fractionation, flotations were performed at varied conditions. The selectivity of fines fractionation was mainly affected by long fiber flocculation degree and if there were not sufficient flocculation of long fibers, more loss of long fibers could not be avoided. The amount of flotation rejects were totally dependent on the stability of froth floated on the stock surface. Only small size fines could stabilize the froth as they hindered the drainage of liquid lamella in flotation-froth. More flotation reject and better flocculation of long fibers were two important factors for improving flotation. Changing a flotation flux or an air-mixing ratio to increase the flocculation of fibers increased long fiber ratio in the reject. In order to satisfy the both conditions of reducing long fiber loss and of increasing flotation reject, search of fractionation promoter is needed.

• 펄프종이기술
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• 제33권3호
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• pp.44-51
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• 2001

Sedimentation characteristics such as SS, $BOD_5$, COD removal efficiency of waste water in the toilet paper mill using milk carton were examined. Optimum dosage of coagulant, rapid mixing time and slow mixing time were determined by turbidity, SS, COD, $BOD_5$ and then equation for treatment efficiency was suggested. Mechanical strength of floc was determined by turbidity. For the coagulant, polyacrylamide (PAM) is more efficient for removing pollution than the aluminium sulfate. Effective mixing ratios of PAM and aluminum sulfate to remove pollution are 70:30 and 30:70. The lowest turbidity was showed when rapid mixing at 300 rpm after coagulant injection was applied. That which indicates the highest point of flocs mechanical strength.

• 펄프종이기술
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• 제30권3호
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• pp.7-14
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• 1998

It is well known that the recycling of pulp generates a lot of fines, and cause the hornification of fiber. Both phenomena have been contributed to a limited use of recycled fiber. Among several means which can improve the properties of recycled fiber, enzymatic treatments are considered as an effective means. Thus the effects of xylanase on the properties of recycled pulp were investigated in this study Xylanase treatment showed some refining effect at a small dosage while the fines and fibrils were reduced at higher dosage as shown in the treatment with cellulase-hemicellulase. The interesting finding is that the WRV of recycled fiber treated with xylanase was higher than that treated with the mixture of cellulase and hemicellulase. Breaking length and tear index of recycled fiber treated with xylanase were also higher.

• 자원리싸이클링
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• 제19권3호
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• pp.62-70
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• 2010

종이에 대한 수요가 꾸준히 증가함에 따라 백상지 고지(White ledger)나 신문지 고지(Old newspaper pulp)등의 재활용지에 대한 중요성이 지속적으로 증가하고 있다. 또한 재활용지의 사용은 산림자원의 보호와 지구온난화 등의 환경문제 차원에서 더욱 부각되고 있다. 하지만 재활용지의 경우 종이에 필수적인 광학적 성질이 저하하고 기계적 성질이 감소하는 등 일반 종이에 비해 단점을 가지고 있다. 이러한 재활용지의 문제점을 보완하기 위해 입자 크기에 따라 $0.1{\mu}m{\sim}0.9{\mu}m$의 교질형 초미립자와 $0.1{\mu}m{\sim}0.9{\mu}m$의 입방형 미립자로 나눠지는 침강성 탄산칼슘을 In-situ 공정으로 재생펄프 표면에 합성하였다. 서로 다른 결정 형태와 크기가 다른 침강성탄산칼슘이 재활용지의 광학적 기계적 물성에 어떠한 영향을 주는지 연구하였다. 또한 화학펄프와의 혼합을 통해 침강성 탄산칼슘이 코팅된 재생펄프의 기계적 물성을 감소시키는 점을 보완하여 다른 첨가물에 전혀 의존하지 않고도 우수 재활용 인증마크인 GR규격을 만족하는지 알아보았다.

• Journal of Forest and Environmental Science
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• 제14권1호
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• pp.89-100
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• 1998

본 연구는 제지 원료의 효율적 이용 및 기능의 최적화를 위한 수단으로 사용되고 있는 다층구조화에 따른 종이의 내부응력 및 물성의 변화를 조사하기 위하여 수행되었다. 또한 최근 사용량이 급증되고 있는 재생섬유를 다층구조에 도입할 경우 수반되는 종이의 물성 변화도 조사되었다. 펄프의 고해처리는 단층지의 내부응력을 증가시켜준 반면 충전제의 사용은 내부응력을 감소시켰다. 종이의 다층구조화는 인열지수를 제외한 대부분의 종이물성과 내부응력을 감소시켰으며, 이러한 변화는 사용된 펄프의 종류, 고해수준, 원료의 배합 방법에 따라 다양하게 나타났다. 충전시에는 충전제를 외층 또는 내층에 사용함으로써 단층지보다 우수한 내부응력 및 종이물성을 얻을 수 있었다. 재생섬유를 사용할 때는 다층구조화를 통하여 투기도와 빳빳이의 개선이 가능하였으나, 파열지수가 감소되었다.

• 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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• 제33권1호
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• pp.16-23
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• 2001

Hydraulic transport of fines up to the surface of flotation cell was supposed to be a mechanism of fines fractionation through the froth-flotation. Efficient fractionation of fines means efficient skimming out of flotation rejects as much as possible with least long fiber loss. The selectivity of fines fractionation was found to be mainly affected by long fibers flocculation degree in this study. Lack of sufficient flocculation of long fibers could lead to extensive loss of long fibers. It was also found that higher flotation flux caused higher flotation reject as well as the increase of long fiber loss, but did not affect the fine content ratio in the flotation reject. We controlled the flotation flux and the stock consistency, and chose a cationic polymer to maximize the flocculation of long fibers and to increase the amount of flotation reject. The highest efficiency of fines fractionation was obtained at 1.3% of stock consistency and at 100L/min of flotation flux in our experimental set up. The cationaic polymer we chose was found to be very effective in fiber flocculation and flotation froth stabilization. New definitions of fractionation efficiency were introduced in this study to compare the results more clearly.