• 임산에너지
• /
• 제18권2호
• /
• pp.70-77
• /
• 1999

간벌 소경재의 새로운 용도개발을 위한 기초연구로서 국내산 주요 침·활엽수 4수종의 알칼리팽윤 특성을 조사하였다. 그 결과, 4수종 모두 알칼리 처리후 밀도가 증가하였으며 그 정도는 활엽수재가 더 크게 나타났다. 알칼리처리에 의해 접선방향의 팽윤이 현저한 반면 방사방향의 팽윤은 작았고, 섬유방향은 오히려 감소하는 경향이 있었다. 알칼리 팽윤후 수축율은 활엽수재가 더 컸으며, 특히 기건상태까지의 수축율은 방사방향과 접선방향간에 수축육의 차이가 거의 없이 등방적으로 수축하는 특징을 보여주었다.

• Journal of the Korean Wood Science and Technology
• /
• 제35권2호
• /
• pp.16-22
• /
• 2007

The behavior of ramie fibers and some wood elements in the early stage of alkali swelling was examined. When the fibers were treated with alkali solution, they significantly shrank in length and swelled in wall thickness. Ramie fibers showed a shrinkage averaging 23% in length and a swelling averaging 92% in width in 100 seconds treating time. Dimensional changes showed different fashion in each element of woods. The tracheids of latewood especially in Pinus densiflora and Larix kaempferi woods swelled intensively and showed balloon swelling, but in the case of Cryptomeria japonica, it was hardly observed. The swelling morphology of libriform fibers was similar to that of tracheids. The walls of vessel elements and parenchyma cells also swelled considerably in thickness but, no balloon swelling was found in both elements. The differences of swelling in different elements can be interpreted in terms of the differences of organization and/or chemical components of the cell walls.

• 펄프종이기술
• /
• 제46권3호
• /
• pp.65-72
• /
• 2014

In this study, effects of alkali swelling at low concentration below 2 percent on properties of hardwood bleached kraft pulp (HwBKP) were elucidated. Swelling treatment of HwBKP was performed at various NaOH concentrations with/without beating. Then, the swelling characteristics of pulp fiber was evaluated by measuring the solvent retention values such as water retention value (WRV) and isopropyl alcohol retention value (LRV). It was found that fiber characteristics were influenced by NaOH swelling even at low alkali concentration and beating treatment as well. The values of WRV and LRV were decreased when the alkali concentration was increased. It is the result from the decreased acidic groups of pulp which were formed during beating. The acidic groups could be neutralized and then removed by alkali. The difference between WRV and LRV was decreased with increasing alkali concentration while the difference was increased when the alkali swollen pulp was beaten. In addition, the crystalline structure of HwBKP was almost not changed while the crystallinity was influenced by swelling treatment at a low alkali concentration.

• 펄프종이기술
• /
• 제46권4호
• /
• pp.69-75
• /
• 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
• /
• 제48권3호
• /
• pp.37-43
• /
• 2016

Various mechanical and chemical pretreatment methods including alkali treatment, pre-beating, enzyme treatment and oxidation treatment have been used to reduce the production energy of the microfibrillated cellulose (MFC). Among them, alkali swelling can be helpful to reduce the energy consumption because the internal bonding between fibrils could be weakened. In this study, dimethyl sulfoxide (DMSO) was used as a cosolvent to improve alkali pretreatment efficiency and the effects of NaOH concentration during NaOH-DMSO swelling on changes in fiber characteristics of softwood bleached kraft pulp (SwBKP) were elucidated. For alkali treatment in H2O-DMSO solvents, fiber length were decreased with increasing NaOH concentration while fiber width, curl and WRV were increased. WRV began to increase at 8% NaOH solution. In addition, above 8% concentration of NaOH, crystalline structure of pulp fibers converted from cellulose II to cellulose III by DMSO cosolvent. Comparing the previous results with this study, it was shown that DMSO cosolvent could promote swelling of pulp fibers and thus reduce NaOH concentration for the maximum swelling of fibers.

• 임산에너지
• /
• 제20권1호
• /
• pp.62-72
• /
• 2001

목재의 알칼리 팽윤특성을ㄹ 해명하기 위해 국내산 주요 침·활엽수 4수종의 주요 구성요소의 알칼리 팽윤 거동을 횡단면 절편을 이용하여 조사하였다. 그 결과, 일본잎갈나무의 가도관 직경은 잣나무보다 크게 팽윤하였으며, 가도관의 벽두께는 10% 이상의 알칼리 수용액에 처리시 높은 팽윤율을 나타냈다. 알칼리 처리에 의해 도관의 직경은 방사방향으로 수축하였고, 접선방향으로 다소 팽윤하였다. 목섬유의 세코벽두께는 5%의 알칼리처리에서도 수분팽윤에 비해 3배 이상의 높은 팽윤성을 나타앴고, 알칼리 처리후 일본잎갈나무의 가도관 직경, 목섬유 직경 및 세포벽두께는 거의 등방적인 수축현상을 보여주었다. 또한 미처리 시료에 비해 머서화 처리 구성요소의 세포직경은 수축되었고, 세포벽은 팽윤되었다. 알칼리처리 과정에서 셀룰로오스 결정형의 변화는 없었지만 상대결정화도와 미결정의 폭이 다소 증가되었다. 결론적으로 알칼리의 농도, 수종, 세포의 종류가 목재의 알칼리 팽윤 특성에 크게 관여하는 것으로 생각되었다.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
• /
• pp.220-223
• /
• 2006

To investigate the effect of solution pH and particle size of Na-bentonite on swelling characteristics and relative hydraulic conductivity, four kinds of acids and two alkali were selected. The results showed that the swelling was decreased to half of the original Na-bentonite's swelling index. Also the decrease in SI was most distinctive in pH 3.5 of HCl. But changes of swelling index between initial and stabilized were minimal in alkali treatment, compared to the change by acid treatment. No flux was detected under atmospheric pressure although there was drastic decrease in swelling. However, leaching started after application of 1.5 bars of air-pressure equivalent to 15 m of water head.

• Geomechanics and Engineering
• /
• 제19권1호
• /
• pp.21-28
• /
• 2019

Use of cement in stabilizing the sulfate-bearing clay soils forms ettringite/ thaumasite in the presence of moisture leads to excessive swelling and causes damages to structures built on them. The development and use of non-traditional stabilisers such as alkali activated ground granulated blast-furnace slag (AGGBS) and enzyme for soil stabilisation is recommended because of its lower cost and the non detrimental effects on the environment. The objective of the study is to investigate the effectiveness of AGGBS and enzyme on improving the volume change properties of sulfate bearing soil as compared to ordinary Portland cement (OPC). The soil for present study has been collected from Tilda, Chhattisgarh, India and 5000 ppm of sodium sulfate has been added. Various dosages of the selected stabilizers have been used and the effect on plasticity index, differential swell index and swelling pressure has been evaluated. XRD, SEM and EDX were also done on the untreated and treated soil for identifying the mineralogical and microstructural changes. The tests results show that the AGGBS and enzyme treated soil reduces swelling and plasticity characteristics whereas OPC treated soil shows an increase in swelling behaviour. It is observed that the swell pressure of the OPC-treated sulfate bearing soil became 1.5 times higher than that of the OPC treated non-sulfate soil.

• 펄프종이기술
• /
• 제41권4호
• /
• pp.58-64
• /
• 2009

This study was carried out to prepare high porosity pulp for oil and air filter media from commercial grade NBKP with 6 - 20% NaOH treatment. The fiber width of NBKP remarkably decreased by NaOH pretreatment. The air permeability of the test sheet prepared from alkali-pretreated NBKP increased with increasing NaOH concentration up to 15%. The burst factor was greatly decreased by alkali pretreatment. By 15 - 20% NaOH pretreatment of NBKP, it could be possible to prepare a high porosity pulp. It seems that the high porosity of the pulp was due to a strong swelling and a great change of the cellulose crystalline lattice from cellulose I to cellulose II with NaOH treatment of NBKP. The study suggested that alkali- pretreated NBKP could be used for manufacturing oil and air filter media.

• 한국염색가공학회지
• /
• 제4권3호
• /
• pp.91-96
• /
• 1992

The crystalline character of NaOH and KOH-cellulose complex having different tension ratio was studied using X-ray diffraction analysis. Cellulose crystalline lattices in tension alkali treatment cotton were identified by measuring and indexing the 101, 101, and 002 reflections. According as alkali treatment tension ratio increased on, cellulose gave rise to the formation of I rather than cellulose II. It seemed that a part of the fine structure of cellulose increased orientation with antiparaell and parallel chain crystal structure. The high tension ratio alkali treatment cotton resulted in lower dye sorption and in higher breaking strength and crease recovery.