• 펄프종이기술
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• 제43권2호
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• pp.57-65
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• 2011

Pulping of paper mulberry (Broussonetia kazinoki) white bast has been examined by novel atmospheric pressure pulping methods. The viscosity of pulp has been found to be highly sensitive and variable with pulping methods. Therefore, selections of pulping chemicals and conditions are very important. Two kinds of pulping procedures were employed for the high viscosity pulp manufacturing. The one is ammonium oxalate treatment and the other is sodium chlorite and acetic acid treatment. Not only chemical components and pulp yields which of paper mulberry white bast but also water retention value (WRV), whiteness index, yellowness index, and colors of every pulp were examined. The hot water, 1% NaOH, and ethanol-benzene extractives which of paper mulberry white bast were 4.48%, 28.45%, and 2.84%, respectively. The contents of holocellulose, lignin, and ash were 90.66%, 1.05%, and 2.18%, respectively. In the pulp yields, group 1 which treated with only ammonium oxalate were 77.04-81.71%, group 2 which treated with ammonium oxalate and acidified sodium chlorite separately and washed between first and second stages were 64.15-83.90%, group 3 which treated with ammonium oxalate and acidified sodium chlorite separately and not washed between first and second stages were 57.35-73.17%, and group 4 which treated with mixed ammonium oxalate and acidified sodium chlorite were 66.58-68.43%. The pulps treated with acidified sodium chlorite showed high whiteness index, but the pulps treated with only ammonium oxalate showed high yellowness index. Variations in the combinations of treatments resulted in different pulp characteristics.

• 펄프종이기술
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• 제35권1호
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• pp.41-47
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• 2003

Recently, interest in utilization plan of recycling paper have been enhanced. Therefore, this research aimed to develop the manufacture process of cellulose acetate using old newsprint by acetosolv pulping process. And the manufactured cellulose acetate was also analyzed, especially based on chemical properties. The summarized results in this research were as follows; Reaction time, kind and amount of catalyst, and ratio of liquor to material were varied during acetosolv pulping process of old newsprint. Ratio of liquor to material did not give the significant difference in reaction product. Delignification rate was increased with increasing reaction time during acetosolv pulping, but yield and degree of substitution decreased with increasing reaction time. Sulfuric acid are better catalyst than hydrochloric acid in acetosolv pulping process for old newsprint, and optimal addition amount of catalyst was 1% based on reaction material. Delignification, yield, and degree of substitution were influenced by the catalyst and reaction time. Under pulping condition of $120^{\circ}C$ in 1/12 liquor to material ratio and 60min, degree of substitution was about 0.7. The acetylation reaction was not completely caused by these reaction condition. The examination of the FT-IR spectra revealed that absorption band(1200$\textrm{cm}^{-2}$, 1,750$\textrm{cm}^{-1}$) caused by carbonyl group were confirmed.

• 펄프종이기술
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• 제37권5호통권113호
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• pp.41-49
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• 2005

This paper deals the effect of anthraquinone (AQ) on the contribution of sulphidity in kraft pulping of sapwood. The pulping conditions namely- active alkali concentration, pulpingtime, temperature and liquor ratio were varied in low ($15\%$) and high ($30\%$) sulphidity. $0.1\%$ AQ was added in the low and high sulphidity pulping with varying active alkali concentration and cooking time. At optimum conditions, low sulphidity kraft process produced about $44\%$ pulp yield with kappa number of about 23. But in high sulphidity kraft process kappa number was reduced to about 20 at the same yield. An addition of AQ reduced alkali requirement by $2\%$ on oven dried raw material and cooking time by 1 hour to produce pulp yield of about $44\%$ at kappa number 20. AQ is more effective in low sulphidity pulping than the high sulphidity pulping. The breaking length of kraft-AQ pulp was slightly higher than that of kraft pulp.

• 펄프종이기술
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• 제47권2호
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• pp.1-8
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• 2015

Disposable diaper has been used in order to handle urine and feces conveniently. At present the amount of disposable diaper waste increases gradually. Incineration and landfill have been the only ways to dispose of disposable diapers. However, if they are disposed by landfill, decomposition will take more than one hundred years. In addition, another way of dispose incineration has caused air pollution. Therefore, it is necessary to study recycling process for disposable diaper since plastic and wood fibers of diaper are useful materials to recycle. In this study, pulping condition of disposable diaper waste was studied in order to effectively separate the components. Recovery rates of plastic and fibers were analyzed under different pulping conditions. It was found that optimum pulping consistency was 5%, time was 60 minutes, temperature was $50^{\circ}C$, and cut size is $21cm{\times}21cm$. The recovery rate of plastic and fibers can be achieved above 70% under the optimum pulping condition.

• Journal of the Korean Wood Science and Technology
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• 제49권4호
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• pp.287-298
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• 2021

Torch ginger (Etlingera elatior Jack) is a potential source of lignocellulose material for various derivative products. This study aims to determine the chemical components, ratio of syringyl to guaiacyl units (S/G) in lignin, and crystallinity of the biomass of torch ginger. The effects of soda pulping on the chemical characteristics of torch ginger pulp were also studied. Pulping of the chips was conducted with active alkali of 15%, 20%, and 25% and a Liquor-to-Wood (L/W) ratio of 4:1, 5:1, and 6:1. The impregnation and pulping times at maximum temperature (170℃) were 120 and 90 min, respectively. To assess the effect of treatments on the properties of pulping, a two-factorial experimental design was applied. Results showed that the content of α-cellulose and hemicellulose in the torch ginger was 48.48% and 31.50%, respectively, with an S/G ratio of 0.70 in lignin. Soda pulping changed the crystalline structure of the biomass from triclinic to monoclinic. Active alkali, L/W ratio, and interactions considerably influenced the observed responses. The degree of delignification increased with an increase in the loading of active alkali, which lead to a decrease in the kappa number of the pulp. An active alkali content of 25% and an L/W ratio of 6:1 resulted in the highest delignification selectivity with a kappa number of 2.78 and a yield of 24%. Given its cellulose content and ease of pulping, torch ginger can be a potential raw material for derivative products that require delignification as pretreatment. However, the increase in cellulose crystallinity should be considered when converting torch ginger to bioethanol.

• Journal of the Korean Wood Science and Technology
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• 제34권5호
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• pp.104-110
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• 2006

We investigated why aspen extractives are more resistant in kraft pulping than pine extractives. Residual extractives content in aspen kraft pulps were 0.5~1.1% compared with 0.1~0.2% in pine pulps. This different response arises from the different composition of extractives in wood chips. Resin acids in pine were almost completely removed in kraft pulping but those are not existence in aspen. Slower saponification of aspen steryl esters resulted from different chemical structure of aspen steryl esters. Main sterols in aspen steryl esters were 24-methyl cyclolanostenol which was highly resistant to alkaline hydrolysis with its characteristic steric hindrance. Sterols in aspen were not well removed in kraft pulping. The relative composition of sterol in aspen kraft pulps was increased with increasing pulping time. The presence of fatty acids in aspen kraft pulps is considered to unusual. Fatty acids in alkaline are supposed to be well ionized and removed well in the washing stage. Nevertheless, there were significant amount of fatty acids remaining in aspen kraft pulps.

• 펄프종이기술
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• 제38권3호
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• pp.38-46
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• 2006

This study was carried out to investigate the sheet properties of Morus Hanji, made by different pulping methods, such as alkali, alkali-peroxide and sulfomethylated pulping, and different stocks composed to bast and whole stalk fibers. Two species of Morus, M. alba and M. lhou, were used. Pulp yield of the whole stalk parts, its brightness and opacity were higher than those of bast part. In particular sulfomethylated pulp has higher brightness of $62{\sim}63%$, than other pulps(average brightness $30{\sim}40%$). In mechanical properties, paper made of bast fiber has higher strength than those of the whole stalks. Hanji made from M. lhou, whole stalk, and sulfomethylated pulp gave better sheet formation and higher strength than those of the others. Hanji from M. alba bast fiber and whole stalk pulps were not so good sheet properties.

• 펄프종이기술
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• 제33권2호
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• pp.58-67
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• 2001

MOW (Mixed Office Waste) mainly consisted of photocopied paper is being recycled to produce tissue or fine paper products. Toner particles that are fused and set on paper surface in photocopying process turns into large and plate-shaped particles after repulping which prevents them to be removed effectively in flotation deinking. The immediate purpose of this study is to find the effective deinking technology that increases the recycling potential of photocopied papers for manufacturing tissue and fine paper products. In this study the effects of pulping temperature and the type of hydrophobic groups of nonionic surfactants on the deinking efficiency of photocopied paper has been investigated. Particle size distribution of the toner particles after pulping and flotation, brightness, yield and ash removal were investigated. The size of toner particles after pulping increased as the pulping temperature was increased. When pulping at the low temperature finer toner particles were generated, however, greater amount of toner particles was found to attach to the fiber. When the pulping temperature was greater than Tg of the toner, the amount of coarse hairy particles increased. When nonionic surfactants with a double bond in hydrophobic groups were used, toner removal efficiency, brightness and ash removal were increased. As the addition level of surfactant was increased, yield decreased rather sharply without improving brightness.

• 펄프종이기술
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• 제40권4호
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• pp.1-9
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• 2008

The utilization of non-woody fibers with the fast growing annual plants has occurred in the paper industry to replace wood and preserve environment of the earth. The non-woody fibers generally used for papermaking are paper mulberry, gampi, manila hemp, rice straw, bamboo, and coton linter etc.. Recently Kenaf has been spot-lighted for the same application. Kenaf is an annual plant of Hibiscus species of Malvaceae family. Kenaf, a rapid growing and high harvesting non-woody fiber plant, was identified as one of the promising fiber sources for the production of paper pulp. This study was carried out to investigate the pulping characteristics of Kenaf bast fiber for Hanji (traditional Korean paper) manufacturing by different pulping methods, such as alkali, alkali-peroxide and sulfomethylated pulpings. It was possible to make superior grade of Hanji. Especially sulfomethylated pulping was resulted in superior pulp in terms of higher yields and qualities in comparison to those of the other pulping methods. Hanji from sulfomethylated pulp was shown the highest brightness of over 60% and higher sheet strength. In addition, the morphological features of pulp fibers (pulp compositions) affect to the sheet properties. Therefore the effect of fiber distribution index(FDI) which was calculated from the data of Confocal laser scanning microscopy(CLSM) on the sheet properties of Kenaf Hanji was also discussed.

• 펄프종이기술
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• 제42권4호
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• pp.56-63
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• 2010

Microcrystalline cellulose (MCC) was prepared from Miscanthus in this study. Two pulping methods, soda pulping and alkaline sulfite pulping were applied as a pretreatment process. After pulping, two different bleaching processes such as $ClO_2$ treatment followed by $H_2O_2$ treatment and $O_3$ treatment followed by $H_2O_2$ treatment were carried out. Two concentration of $H_2SO_4$, 47% and 57% were applied to the purified Miscanthus cellulose as a acid hydrolysis process to make MCC. The crystallinity index and morphological properties of the produced MCC were evaluated with X-ray diffractometer and scanning electron microscopy. The MCC originated from the soda pulping sample showed the higher crystallinity index than that originated from the alkaline sulfite pulping sample. The two stages of treatmen twith $O_3$ and $H_2O_2$ resulted in the higher purified cellulose products.