• 펄프종이기술
• /
• 제45권4호
• /
• pp.27-33
• /
• 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.

• 한국응용과학기술학회지
• /
• 제26권4호
• /
• pp.428-433
• /
• 2009

Cellulose triacetate (CTA) was prepared from cotton linter and pulps which contain various contents of $\alpha$-cellulose. CTA which contains 2.8 of degree of substitution (DS) and 222 of degree of polymerization (DP) was obtained from V-81 pulp under the heterogeneous system. The DS was measured by the titration method, and the DP was obtained by measurement of viscosity. FT-IR spectometer (FT-IR 6300, JASCO) was used to analyze the chemical structure of raw materials and cellulose triacetate, and X-ray diffractometer (X-pert MPD PW3040, Philips) was used to confirm the crystal structure and to calculate the relative crystallinity index (RCI). As $\alpha$-cellulose content in pulp increased, the acetylation yield increased. Besides with a kind of pulp, it contains insoluble residue which was mainly formed due to the formation of glucomannan triacetate and xylan diacetate during the esterification.

• 펄프종이기술
• /
• 제44권3호
• /
• pp.79-85
• /
• 2012

In this study, purified cellulose was prepared from rice husk which is one of the major agricultural residues in Korea. The various bleaching processes such as ozone bleaching, $ClO_2$ bleaching and $H_2O_2$ bleaching were applied to remove residual lignin and impurities. In order to increase the contents of ${\alpha}$-cellulose contents, the effects of acid and alkali treatments were evaluated. Although the multi stages of the bleaching processes resulted in less than 0.5 % residual lignin contents, the application of ozone leaded to the decrease in DP(degree in Polymerization) and ${\alpha}$-cellulose contents. The alkali treatment after bleaching processes resulted in pure cellulose which showed more than 98% of ${\alpha}$-cellulose contents.

• 펄프종이기술
• /
• 제39권3호
• /
• pp.77-83
• /
• 2007

This study was carried out to examine the optimum culture condition for the production of cellulose from Saprolegnia ferax and its physical characteristics. Conclusions obtained from the results of this study were as follows: In producing the cellulose from S. ferex, optimal pH and temperature were 7.0 and $26{\sim}30^{\circ}C$ with a maximum of $26^{\circ}C$, respectively. And, optimal culture period was 11days. WHC and OHC of biocellulose were 3.2(25.04 g/g) times and 3.5(25.75 g/g) times higher than those of commercial ${\alpha}-cellulose$(7.57, 7.25 g/g) respectively. The viscosity of biocellulose is lower than that of commercial ${\alpha}-cellulose$. And the effect of rpm on the viscosity of biocellulose was more than on the that of ${\alpha}-cellulose$.

• 펄프종이기술
• /
• 제31권2호
• /
• pp.1-7
• /
• 1999

In this paper, five lignin model compounds (vanilly alcohol, veratryl alcohol, veratryl methyl carbinol, biseugenol) and three cellulose model compounds (${\alpha}$-D-glucos, methyl-${\beta}$-D-glucopyra-noside, D-cellobiose) were used to study the degradation rates of lignin and cellulose with chlorine dioxide. Biseugenol, which has unsaturated structure on the side chain of aromatic ring, was found to react with chlorine dioxide very quickly and consume large amount of chlorine dioxide. Phenolic structures, represented by veratryl alcohol and apocynol, react with chlorine dioxide much faster than nonphenolic structures represented by veratryl alcohol and veratryl methyl carbinol. The degradations of cellulose models were generally very slight, the corder of reaction rate being ${\alpha}$-D-glucose > D-cellobiose > methyl-${\alpha}$-D-glucopyranoside.

• Journal of the Korean Wood Science and Technology
• /
• 제25권4호
• /
• pp.68-74
• /
• 1997

This research was studied dissolving pulp for rayon production, which is not KP, SP methods but steam explosion and oxygen alkali treatment. The variation of characterization in wood cellulose after steam explosion and oxygen alkali treatment this follows. In the oxygen alkali treatment of exploded pine wood, yield of dissolving pulp was lower than steam-exploded oak wood, and we have obtained dissolving pulp that high purity cellulose, but degree of polymerization was inclined to decrease less than 200. In the case of steam-exploded oak wood, degree of polymerization was higher than steam-exploded pine wood but purity of cellulose was lower than its.

• 펄프종이기술
• /
• 제39권5호
• /
• pp.20-25
• /
• 2007

Henequen fibers were treated by electron beam irradiation and by NaOH to make surface modification for better bonding in the manufacture of biocomposite. Impurity removal and carbonyl group formation were noticed in the previous study by electron beam irradiation, but extensive cellulose degradation were also noticed. To evaluate the effects of electron beam irradiation on cellulosic fibers further, henequen fibers, cotton pulp, cotton fibers, and cellophane were irradiated by electron beam, and their changes of cellulose viscosity, chemical composition, and tensile strength were measured and analyzed.

• 펄프종이기술
• /
• 제45권3호
• /
• pp.27-35
• /
• 2013

Cotton linter pre-treatment methods using electron beam and sulfuric acid were investigated to prepare high quality regenerated fibers for fabrics. So far, NaOH was used to reduce the degree of polymerization (DP) of the cotton linter for ease of dissolving by cellulose solvent. Two pre-treatment methods were developed to reduce the consumption of the chemicals (NaOH) and to control the DP of cellulose more precisely. Changes in ${\alpha}$-cellulose contents and brightness by the pre-treatments were also important concerns. Both electron beam irradiation and sulfuric acid were shown to be effective on controlling the DP of cellulose and to reduce the chemical consumption, but reduced ${\alpha}$-cellulose contents as well in this study. Sulfuric acid pre-treatment, which needed additional washing process after the pre-treatment when comparing to the electron beam irradiation method, gave the highest brightness and the highest reduction of ${\alpha}$-cellulose content.

• 펄프종이기술
• /
• 제46권4호
• /
• pp.37-43
• /
• 2014

The crystallinity and molecular weight of cotton linter need to be controlled to be more easily dissolved in NMMO during manufacture of clothing fabrics. Electron beam irradiation and sulfuric acid treatment were used as pre-treatment to reduce molecular weight of cotton linter more efficiently, and after the pre-treatment, peroxide bleaching was followed in alkaline condition. After those processes, the crystalline indices of the cotton linters were measured by XRD method, and other properties such as their alpha cellulose contents and degree of polymerization were measured. It was found that the crystallinity index of cotton linter was decreased as the irradiation of electron beam increased while increased as the dose of sulfuric acid increased. These results strongly suggested that electron beam damaged the crystalline structure of the cellulose directly while sulfuric acid dissolved mostly non-crystalline area of the cellulose structure.

• 문화기술의 융합
• /
• 제5권4호
• /
• pp.355-359
• /
• 2019

건성안 진단에 있어서 가장 많이 사용되는 방법 중 하나이나, 부정확한 결과로 신뢰도가 떨어지는 쉬르머 검사법을 대체할 수 있는 눈물양 측정 도구를 개발하고자 하였다. 이를 위해 다양한 흡수제에 대한 흡수성 시험을 통하여 알파 셀룰로즈 펄프를 흡수제로 선택하였다. 2차례에 걸쳐 시제품을 제작하여 평가하였으며, 최종적으로 알파 셀룰로즈 펄프를 폴리우레탄에 접착한 스트립 형태의 눈물양 측정 도구를 제작하여 사용성 평가를 실시하였다. 그 결과 해외에서 최근에 개발된 눈물양 측정 도구인 Strip Meniscometry와 유의한 상관성을 갖는 것을 확인할 수 있었으며, 측정시간 및 측정의 정확성 측면에서 쉬르머 검사법의 대체 검사법으로 유효한 것으로 판단되었다.