• 펄프종이기술
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• 제45권4호
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• pp.27-33
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• 2013

Manufacturing fabrics from dissolving cellulosic pulp is increasing in these days. For making high quality of cellulose-based fabrics, control of cellulose DP (degree of polymerization), its alpha cellulose content, its brightness, and its crystallinity are important. To process the cellulosic raw material, refining of cellulosic fibers is essential, and it is important to know if refining affects those important cellulose properties. The effects of PFI mill and Valley beater refining on the alpha-cellulose content, cellulose DP, crystallinity, and paper mechanical properties of wood and two different cotton fibers were studied. The results showed that PFI mill refining rarely affected those properties. Fibers refined by a Valley beater displayed a small reduction in fiber length in comparison with those refined by a PFI mill. However, the Valley beater refining method produced almost no changes in cellulose properties, either. The refining process seemed to have very little effect on the cellulose DP, crystallinity index, or alpha-cellulose content until the freeness decreased to around 300 mL CSF for wood and 100 mL CSF for cotton fibers, respectively. There were also no differences in tensile strength development in two refining methods.

• 농업과학연구
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• 제26권1호
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• pp.21-30
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• 1999

본 연구는 골판지고지의 가장 중요한 물성인 강도적 성질을 증대시키기 위하여 섬유의 전처리 방법으로서 Hobart mixer를 사용하여 섬유 내부의 결합제거 및 섬유표면에 Microcompression을 형성하여 개질처리 하였으며, 4가지 방법의 고해방법(Valley beater, Kady mill, Impact refining)을 채택하여 골판지고지의 최적고해 방법을 찾는데 그 목적을 두고 이 연구를 수행하였다. 그 결과는 다음과 같다. 1. 섬유장감소를 적게 유발하는 고해방법으로는 Kady mill과 PFI mill의 고해방법 이었으며 고해시 Curl을 펴주는 고해방법을 Kady mell과 Valley beater의 고해방법이 적절하였다. 2. 열단장은 Valley beating의 고해방법에 의하여 강도가 가장 많이 증가되었으며 인열강도는 가장 많이 감소하였다. 섬유전처리를 한 Comp-1과 Comp-2는 고해방식과 상관없이 열단장을 전체적으로 약 10% 증대시켰다. 3. 인열강도는 Comp-1, Comp-2의 전처리방법과 PFI mill 고해로 증대할수 있었다. 4. 파열강도는 Comp-1, Comp-2의 전처리방법과 Valley beater 고해로 증대할수 있었다. 5. 인열강도를 우지한채로 열단장을 가장 높이는 방법은 섬유전처리 방식인 Comp-1이나 Comp-2를 사용하여 Valley beating을 이용하는 방법으로 판단되었다.

• 펄프종이기술
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• 제32권1호
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• pp.10-18
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• 2000

To improve the physical properties of OCC (Old Corrugated Container) fibers, we used the mechanical pre-treatment on the fibers before refining . The mechanical action in the Hobart mixer induced high shear and compression on the fibers, which resulted in changes of fiber internal structure, and microcompressions on the surface of the fibers. We evaluated the amount of mechanical treatment on the fibers by fiber curl index for convenience. Four different refining techniques were applied to the pre-treated fibers (valley beater, Kady mill, PFI mill, and Impact refining) to find the best combination of the pre-treatment and the refining methods. Conclusions were summarized as followed. 1. Mechanical pre-treatment in Hobart mixer for more than 1 hour caused the increase of curl index of OCC fibers, and increased breaking length, burst index, and tear index the handsheets more than 10 % in this experiment. 2. Kady mill and PFI mill refining were effective in keeping fiber length from shortening Kady mill and Valley beater refining straightened out the fiber curls, and reduced the curl index. 3. Valley beating reduced fiber length very fast and generated fines more than other refining methods. 4. To increase breaking length and burst strength while keeping tear strength , combination of mechanical pre-treatment and Valley beating were most effective.

• 농업과학연구
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• 제38권1호
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• pp.95-100
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• 2011

In the present study, effects of autohydrolysis treatment on the properties of rice hull were investigated. Two temperature condition such as $160^{\circ}C$ and $180^{\circ}C$ and thee treatment time such as 15 min, 30 min and 45 min were applied for autohydrolysis treatment. The pH of extract after autohydrolysis treatment decreased as increasing of the temperature and the treatment time. The ash content and the lignin content of rice hull were not decreased by the autohydrolysis treatment. The structure of rice hull after autohydrolysis treatment became more weak, the better efficiency of the fiberization with PFI-Mill was shown for the autohydrolysis treated rice hull with the higher temperature and the longer treatment time.

• 펄프종이기술
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• 제33권1호
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• pp.38-44
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• 2001

The effects of refining load on the paper properties were investigated. HwBKP, SwBKP and SwUKP were refined with PFI mill at the load of 3.33 N/mm and 6.00 N/mm. Higher Scott bond was obtained at the higher refining load for three pulp used in this study. However any changes in the light scattering coefficient with the change of refining load were not observed. Although the effect of refining load on the formation index for SwUKP was not observed, higher refining load gave the better formation for HwBKP and SwBKP. The fiber mass and fiber crowding factor were not affected by the refining load. Higher apparent density and tensile index were obtained with the higher refining load. However, the higher refining load did not improve the tensile index at the same apparent density. The tear index was decreased with the increase of refining load.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2011년도 춘계학술발표회 논문집
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• pp.139-150
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• 2011

The effects of the high pressure and the high temperature digesting process with water on the properties of rice hull were investigated in this work. Two temperature condition such as $160^{\circ}C$ and $180^{\circ}C$ and thee treatment time such as 15 min, 30 min and 45 min were applied for this treatment. The pH of extract after the digestion process decreased as the temperature and the treatment time of the digestion were increased. The ash content and lignin content were not decreased by the the digestion. The structure of rice hull after digestion treatment became more weak, the better efficiency of the fiberization with PFI-Mill was shown for the digestion treated rice hull with the higher temperature and the longer treatment time.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.1
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• pp.31-36
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• 2006

Tritium has been used to directly measure the exchangeable hydrogen in bleached softwood kraft pulp. The hydrogen atoms associated with hydroxyl groups in pulp or with water contained in the pulp can dissociate and exchange with the hydrogen atoms in bulk water. Tritium is a radioactive isotope of hydrogen and behaves almost identically to it. The distribution of tritium between pulp and water ($k_{pw}$) can be easily measured and becomes an index of the protons available fur hydrogen bonding. Bleached kraft pulp was refined in a PFI mill to a range of freenesses. Tritiated water was added and the amount exchanged measured. There was a slight steady increase in $k_{pw}$ until approximately 300 CSF; $k_{pw}$ then rose sharply between 300 CSF and 100 CSF. This rise appears to correlate with FSP. It is likely that the action of refining on the fiber reaches a threshold at about 300 CSF causing the fiber surface to break open creating exponentially more surface area. This theory is visually confirmed through light microscopy. The slow increase in fibrillation of the fibers above 300 CSF correlates with the increase in $k_{pw}$. Beyond the threshold of 300 CSF a dramatic difference in fibrillation is shown, also corresponding with the large increase in $k_{pw}$. The freeness difference around 300 CSF is small, but the change in fiber properties is extreme within this region. This change in properties could lead to sheet breaks and other disruptions when producing products around the threshold. This study leads to a better understanding of how fiber changes during refining, resulting in a practical benefit of target freeness determination. Presently, freeness is selected based on product quality and on some measure of runnability. Yet, there are other considerations, demonstrated by the extreme change in fiber properties around 300 CSF.