• 펄프종이기술
• /
• 제35권4호
• /
• pp.1-7
• /
• 2003

In this study, fiber mechanical pretreatment before refining was executed with the addition of papermaking addiditives to find synergistic effects on fiber property improvement. Three fiber furnishes (SwBKP, KOCC, and BCTMP), and five different additives (CMC, CPAM, PEO, NaOH, $Na_2O_2$) were used. It was confirmed again that fiber mechanical pretreatment using Hobart mixer was a special way to modify fiber properties, where fiber WRV (water retention value) increases without losing fiber length. For SwBKP, addition of small amount of CMC (0.2％ OD basis), and for KOCC, PEO (0.2％ OD basis) caused additional significant improvement of the fiber furnish properties, respectively. Other additives did not cause adverse effects on the mechanical pretreatment, or better. For BCTMP, NaOH addition followed by mechanical pretreatment caused more than 20％ improvement in tensile and tear strength simultaneously, compared to the control. The yellowing caused by the treatment of NaOH on BCTMP could be minimized by using $Na_2O_2$ without losing the positive effect of NaOH.

• 펄프종이기술
• /
• 제41권3호
• /
• pp.29-34
• /
• 2009

Electroconductive papers were manufactured as handsheet by mixing carbon fiber in LBKP and BCTMP. The electrical conductivity of the paper was improved by increasing carbon fiber content and basis weight. The porosity was increased and tensile strength was decreased by the addition of carbon fiber. Electrical conductivity of carbon fiber and BCTMP-based sheet was much better than those of carbon fiber and LBKP-based one. This result indicated that the electrical conductivity of paper can be affected by the kinds of raw material of wood fibers used.

• 펄프종이기술
• /
• 제39권4호
• /
• pp.7-13
• /
• 2007

Effects of pulp type, refining and filler type on the pore characteristics and physical properties of paper were investigated. HwBKP, SwBKP and BCTMP are used to study the effect of pulp type in this study. The effects of each filler (PCC, GCC and talc) and the combination of PCC/GCC were also studied. Highest bulk, pore volume and light scattering are obtained from BCTMP and PCC. It was found that the pore size and pore volume are important in light scattering in paper structure. It was found that PCC was the most effective filler for the improvement of the bulk and light scattering because of the increase in pore volume which can scatter light, but the increase of PCC content was not so effective in the improvement of bulk.

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

• 펄프종이기술
• /
• 제47권3호
• /
• pp.47-54
• /
• 2015

In this study, effects of kneading treatment on the properties of hardwood bleached kraft pulp (HwBKP), softwood bleached kraft pulp (SwBKP) and hardwood bleached chemi-thermo-mechanical pulp (HwBCTMP) were elucidated with a laboratory two-shaft kneader. Kneading treatment was performed at 30% (w/w) of pulp concentration and the number of passes through the kneader was adjusted from 0 to 10 passes. Then, changes in properties of pulp fibers were evaluated. It was found that fiber characteristics were influenced by kneading treatment. Fiber length was decreased with kneading while other morphological properties such as fiber width, curl and kink became increased as the number of passes through the kneader increased from 0 to 5 passes. The magnitude of changes in the morphological properties of softwood chemical pulp was the largest, followed by hardwood chemical pulp. The morphological properties of HwBCTMP were little influenced by kneading treatment. Swelling of fiber measured by WRV was increased with kneading except of HwBCTMP.

• 펄프종이기술
• /
• 제37권2호
• /
• pp.1-10
• /
• 2005

Removal of fines from fiber furnish by fractionation improves drainage, but decreases fiber bonding in paper. Fines can be again classified by their size such as the fines that passed 150 and 400 mesh screen, respectively. A hypothesis of different properties between these two kinds of fines was tested. Four different furnishes (SwBKP, HwBKP, KOCC, and BCTMP) were refined in two levels, and all their furnish and handsheet properties were compared in respect of their fines. KOCC fines gave the slowest drainage and least contribution to breaking length while BCTMP fines the fastest drainage and the highest contribution to breaking length. Removal of the fines that passed 400 mesh screen gave high improvement in drainage and large decrease in breaking length. Only KOCC fines removal gave more positive results where there were large improvement in drainage but only small decrease in breaking length.

• 한국펄프종이공학회:학술대회논문집
• /
• 한국펄프종이공학회 2005년도 추계학술발표논문집
• /
• pp.259-263
• /
• 2005

This study was performed to introduce recently developed Polyvinylamine as a wet-end process improving aids and paper properties improving aids. As a retention and drainage aids, cationicity of Polyvinylamine was a very important factor of BCTMP and ONP stock condition. As a dry tensile strength aids, The hydrogen bond of acrylamide functionality and hydroxyl functionality of the pulp was a very important factor of LBKP stock condition and cationicity of Polyvinylamine was a very important factor of BCTMP and ONP stock condition.

• 펄프종이기술
• /
• 제37권2호
• /
• pp.11-20
• /
• 2005

This study was carried out to investigate the influence of paper stock type and heat treatment on sizing effect. Various types of pulps were used to make handsheets sized internally with AKD(alkyl ketene dimer) and externally with CMC(carboxyl methyl cellulose). Most of the handsheets were treated with heat by dry oven $(100^{\circ}C,\;30min)$ to evaluate the effect of heat treatment on sizing development. Internal sizing development of newsprint was very bad, but the effect of heat treatment was much higher than those of NBKP, BCTMP. In case of surface sizing, newsprint was more effective compared to the other pulps. Considering above mentioned results, it seems that internal sizing slows down water into paper by molecular diffusion much more than capillary penetration, but surface sizing slows down capillary penetration. With regard to density, a higher thickness sheets showed high heat treatment effect on sizing, therefore it assumed that heat treatment effect on sizing had very close relationship with sheet density.

• 한국펄프종이공학회:학술대회논문집
• /
• 한국펄프종이공학회 1999년도 Pre-symposium of the 10th ISWPC Recent Advances in Paper Science and Technology
• /
• pp.375-380
• /
• 1999

In order to improve the optical properties of high yield pulp, bleached chemi-thermo-mechanical pulp (BCTMP) was produced from CTMP of Betula maximowicziana Regel by two staged ozone-hydrogen peroxide bleaching. This pulp was used for the evaluation of the improvement of optical properties, chemical characteristics of lignin in fiber, and the relationship between lignin and optical properties in fiber cell wall. By hydrogen peroxide treatment, the brightness was improved, but the post color number (PC No.) was not. There was little improvement on optical properties by ozone treatment, but his could be solved by using two staged ozone-hydrogen peroxide bleaching. The hydrogen peroxide treatment did not make nay change on chemical characteristics of lignin in cell wall, but by ozone treatment, it was found that the non-aromatic conjugated structure was existed in the surface of cell wall, but this could be removed by hydrogen peroxide treatment in two staged ozone-hydrogen peroxide treatment. Therefore, the optical properties was significantly improved due to the removal of non-aromatic conjugated structure.

• 펄프종이기술
• /
• 제39권4호
• /
• pp.53-60
• /
• 2007

LbL multilayering technology introduced by Decher is a nano technique that a substrate surface is layered by the successive deposition of polyelectrolytes with positive and negative charge. We investigated the electrochemical properties of LbL multilayered pulp fibers with poly-DADMAC and PSS. Three types of pulp-Hw-BKP, BCTMP and KOCC- were treated with polyelectrolytes. Zeta potentials of multilayered fibers ranged from +30 mV to +40 mV, depending on the intial zeta potential of pulp fibers and fines content. All kinds of pulp which were examined in this study, however, showed a similar zeta potential of -35 mV after layering with PSS. To obtain pulp fiber with a uniform and stable zeta potential, BCTMP and KOCC pulp fibers should be multilayered above 5 times. The addition level of polyelectrolytes had little influence on the zeta potential of pulp fibers.