• 한국인쇄학회지
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• 제30권3호
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• pp.35-43
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• 2012

Internal bonding strength of printing paper was increased with sea-algae pulp treatment. Spacially, 9% contents sea-algae pulp treatment in the hardwood pulp are more effective than in the softwood pulp. Most effective mixture ratio of the raw matrials for improvement of the internal bonding strength are softwood pulp 30%, hardwood pulp 70%, sea-algae pulp 9%. Internal bonding strength is effective in more sea-algae pulp contents and softwood pulp contents and wetness.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.395-400
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• 2006

Polylactic acids polymer (PLA) was applied as an additive to improve the strength properties of handsheets prepared from three unbleached southern pine kraft pulps with different kappa number and an aspen bleached chemithermomechanical pulp (BCTMP). The results showed that PLA could greatly improve the tensile and burst strength of the pulp handsheets. Heat pressing effect was also important to enhance the strength properties. For unbleached kraft pulps, it was found that an appropriate amount of residual lignin in pulps had a positive effect on the handsheets strength improvement when adding PLA. The thickness of the handsheet did not change the PLA strengthening effect. In general, PLA effect on tear strength improvement could be neglected. However, it had a significant effect on the improvement of tear strength for the aspen BCTMP handsheets not containing sufficient amount of fines.

• Journal of the Korean Wood Science and Technology
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• 제20권1호
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• pp.51-59
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• 1992

The acetylation of papermaking pulp fiber(SwBKP, SwUKP, HwBKP and HwBCTMF) is carried out to modify the characteristics of pulp and paper. The effects of the addition of acetylated pulp on the filler retention and paper properties were investigated. The acetylation depended upon pulp type and the content of short fiber and fines. The addition of acetylated SwBKP did not deteriorate the retention of clay, talc and calcium carbonate, while the retention of titanium dioxide was increased with the addition of 20% and above. The brightness opacity, air permeability and tear strength were improved, but water resistance, burst strength and folding endurance were decreased by the addition of acetylated SwBKP and SwUKP. The tensile strength of SwBKP was increased until 20% of acetylated pulp is added, and then decreased. The tensile strength of SwUKP, however, was not changed until the acetylated pulp of 25% is added. The dimensional stability was improved by the addition of acetylated pulp and showed the different response to SwBKP and SwUKP.

• 펄프종이기술
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• 제31권3호
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• pp.77-82
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• 1999

The delignification, and optical and strength properties were determined to compare the ozone treatment effect in hardwood and softwood CTMPs. During ozone treatment, the delignificantion was much higher in hardwood pulp than in softwood pulp . The optical and strength properties which were very dependent upon the lignin content in pulp were significantly improved in the case of hardwood pulp . The ozone treatment of high yield pulp was more effective in hardwood pulp than that of softwood pulp.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2007년도 춘계학술대회논문집
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• pp.285-297
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• 2007

As the demands of environment protection increase, the pulp mold container is developed to substitute for the plastic cushion materials like EPS(expanded poly styrene). The water-absorbing ratio, tensile strength and compressive strength of pulp mold are important factors to evaluate its shock absorbing characteristics. The study was performed to investigate the effects of the mechanical property changes on the various conditions of temperature and relative humidity for pulp mold containers made of mixed materials on ONP(old newspaper) and OCC(old corrugated container). This study also is evaluated the optimized mixing ratio of materials for making pulp mold by analyzing the changes of physical properties according to a various procured temperature and relative humidity conditions. The results show that the water absorption ratio of sample increased significantly, and tensile strength decreased $20{\sim}30%$, compressive strength decreased $10{\sim}20%$ by increasing relative humidity condition. And the results show that the ONP 50% and OCC 50% was optimized mixing ratio according to the samples.

• 펄프종이기술
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• 제40권1호
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• pp.47-54
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• 2008

As the demands of environment protection increases, the pulp mold container is developed to substitute for EPS (expanded polystyrene) as a shock absorbing packaging material. The water-absorbing ratio and mechanical properties such as tensile strength and compressive strength of pulp mold are important factors to evaluate its shock absorbing characteristics. Influences of mixing ratios of ONP (old newspaper) and OCC (old corrugated container) on physical properties of pulp mold were investigated at various conditions of temperature and relative humidity. The optimum mixing ratio of ONP and OCC was also searched based on physical properties. The results showed that when relative humidity was increased from 60% to 90%, the water absorption ratio of pulp mold increased significantly, tensile strength decreased 20$\sim$30%, and compressive strength decreased 10$\sim$20%. In addition, the optimum mixing ratio of ONP and OCC was found to be 50%:50%.

• 펄프종이기술
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• 제45권4호
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• pp.16-20
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• 2013

Yellow poplar grown in Korea and imported eucalyptus were compared their kraft pulping characteristics and evaluated the replacing possibility of eucalyptus by yellow poplar. Difference between yellow poplar and eucalyptus were investigated in chemical composition and fiber morphology. Yellow poplar kraft pulp resulted in the higher yield, longer fiber length and thicker fiber, and higher pulp strength than that of eucalyptus. More xylan survived in eucalyptus than yellow poplar during kraft pulping, which led to similar pulp yield even though polysaccharides in Eucalyptus was 4.5% less than in yellow poplar. Longer and thicker yellow poplar pulp fiber resulted in better beating response and pulp strength properties.

• 펄프종이기술
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• 제46권4호
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• pp.69-75
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• 2014

Effects of alkali swelling of HwBKP (hardwood bleached kraft pulp) at a low concentration below 2 percent (based on the oven-dried weight of pulp) on handsheet properties were investigated. Swelling treatment of HwBKP was performed at various low NaOH concentrations with/without beating. Then, the changes in handsheet properties were evaluated in terms of bulk, optical and strength properties. It was found that bulk was slightly increased when the alkali concentration was increased. When the pulp was only swollen without beating, paper optical and strength properties was slightly decreased or not changed with alkali concentration. When the pulp was alkali-swollen after beating, paper strength and opacity showed almost no changes while brightness was increased. When the pulp was beaten after NaOH swelling, alkali concentration showed almost no effect on brightness and opacity of paper. Paper strength was slightly decreased with alkali concentration, suggesting that alkali pretreatment before refining could adversely affect refining efficiency.

• 펄프종이기술
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• 제48권1호
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• pp.111-118
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• 2016

The effects of pulp beating degree and bulky promotor concentration on the properties of handsheet including a bulk and strength have been investigated during manufacturing of low density paper (high bulk paper) with cationic fatty acid bulky promotor. It was found that paper bulk increased with increasing cationic fatty acid bulky agent concentration, while tensile strength decreased. On the other hand the opacity of handseets also increased with increasing cationic fatty acid bulky agent concentration, while brightness decreased slightly. With increasing pulp beating degree, paper bulk as well as tensile strength increased, while opacity decreased. Brightness did not show a significant difference with increasing pulp beating degree. The highest bulk and strength values were observed when 1.5% (SwBKP) and 2% (HwBKP) of bulky promotor was treated into the 450 mL CSF pulp slurry.

• Journal of the Korean Wood Science and Technology
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• 제10권3호
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• pp.168-179
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• 1982

The first step to utilize the growing resources of Italian poplar (Populus euramericana I-476) for pulp-Woods, its characteristics and adaptabilities to the pulp industry must be investigated completely. The plantation methods are important for its fast growing in stock, and no less important is the cutting age for its utilization as pulpwood. In this paper, the stone groundwood pulping, refiner groundwood pulping and chemi-groundwood pulping characteristics by the age of tree, along with their physical and chemical characterstics were tested, and relationships between the age groups were analyzed to find out the optimum felling age. The results obtained are as follows: 1. The coefficient of pliability was a little higher in the case of younger trees. 2. The water retention value of each pulp was directly proportional to its physical strength, but this tendency was not detected between the age groups of sample woods. 3. Generally, the physical strength of younger wood pulp was lower regardless of the pulping process. But in the case of pretreatment with NaOH, Asphund and CGP pulp from 5 year old sample wood were stronger in physical strengths than those of GP and Asplund pulp with no pretreatment from 10 years old sample wood. 4. The tear factor of Asplund pulp with alkali pretreatment was higher than that of CGP pulp but the breaking length and the burst factor was similar in all processes. Considering the pulp yield and its brightness, CGP process seems to be advantageous. 5. The dissimilarity of physical strength between 7 and 10 years old wood pulp was not very large in all pulping processes but the physical strength of 5 year old wood pulp was very weak. In the of groundwood pulping from Italian poplar woods, 5 year old wood pulp should be mixed with other long fiber pulp for making a good paper.