• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.38 no.1 s.113
• /
• pp.16-20
• /
• 2006

The effect of the freeness of pulp slurries on turbidity and transmittance of papermaking stocks was investigated using beaten bleached hardwood pulp stocks with freeness ranging from 651 mL to 403 mL CSF. Also the influence of fiber length on the turbidity and transmittance was examined with fractionated pulp stocks. Increases in stock consistency increased the turbidity. Transmittance of stock samples decreased, however, with the increase of stock consistency. Second order equations and exponential equations have been obtained as regression equations for the turbidity and transmittance of these stock samples, respectively.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.48 no.2
• /
• pp.13-19
• /
• 2016

Moso Bamboo was investigated as the a raw material for pulp and paper industry. Soda-Anthraquinone (Soda-AQ) pulping, elemental chlorine free bleaching was applied. Yield of soda or soda-AQ pulp was 29.3-31.7% with Kappa number 33.0-22.8 with different cooking time or anthraquinone addition at 20% active alkali. In soda or soda-AQ pulping, 81-86% of xylan was removed, which was the main reason for lower pulp yield than hardwood species. Average fiber length of Moso Bamboo soda-AQ pulp was 1.36 mm with $15.5{\mu}m$ fiber width. Soda-AQ pulp from Moso Bamboo (P-3, lowest Kappa pulp) was bleached with 5.5-6.5% of chlorine dioxide charge as D0ED1 bleaching sequence. In 3-stages ECF bleaching, final brightness of 85.3% ISO was achieved with total chlorine dioxide 6.5%.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.40 no.4
• /
• pp.43-50
• /
• 2008

Adsorption of xylans extracted from birchwood and oat spelt on Hw-BKP were analyzed using HPLC. The effect of xylan adsorption on paper properties such as tensile, tear index and brightness was also investigated. The constituents of xylan was analyzed with HPLC after hydrolysis with dilute sulfuric acid. It was shown that xylose was the major constituent and small amounts of glucose and galactose were contained in the xylan samples. Adsorption of xylan on hardwood fibers was evaluated using acid hydrolysis and HPLC techniques. Results showed that the adsorption of negatively charged xylan on the fiber surface was negligible probably because electrostatic repulsion between these two materials. Pretreatment of the fiber with alum increased xylan adsorption. The amount of adsorption increased up to 30 mg/g. With the increase of xylan adsorption both tensile and tear strength of the handsheet increased suggesting xylan can be a very effective strength agents for papermaking. Brightness of the handsheets decreased, however, with the use of xylan.

• Journal of the Korean Wood Science and Technology
• /
• v.48 no.5
• /
• pp.581-590
• /
• 2020

Pulp refining is the major way to alter the properties of fibers and formed paper. Different combinations of the bar profile of the rotor and stator during low consistency refining processes directly affect the properties of the paper. In this study, a mixture of softwood and hardwood pulp was refined by varying the bar angle of the stator while that of the rotor is fixed at 0º. The pulp samples were collected at different refining times. Then, the pulp and paper properties, such as beating degree, fiber external fibrillation, and tensile and tear indexes were measured to explore the effects of the combined refining plates at different bar angles on paper properties. The results of the experiment show that the combined refining plate of 0º and 5º recorded the most significant improvement in the pulp beating degree and fiber external fibrillation. This consequently increased the fiber bonding area, which in turn, improved both the tensile and the tear indexes of the paper. Also, the influence of the combined refining plates with a larger bar angle on the paper properties was weaker compared to that of smaller angles. This study not only provides ideas for the bar profile design but also improves the optimal selection of refining plates.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2003.11a
• /
• pp.148-153
• /
• 2003

The influence of sizing, fiber and pigment type on coating penetration, using commercial paper and two types of handsheets as the base paper which were prepared from thermomechanical pulp(TMP) and hardwood bleached kraft pulp(KP) sized internally with alkyl ketone dimmer(AKD), was studied in terms of characteristics of coating holdout. Laboratory rod draw down coater was used for surface sizing and coating application. Characterization of coating penetration was done by measuring the roughness of the backside of coating layer. The backside of the coating was exposed by dissolving the fibers in a solution of cupriethylenedimine(CED). Data show that internal sizing of base paper is effective and surface sizing is more effective to prevent coating penetration. Comparing between the two types of base papers, backside roughness of coating layer of TMP sheet is much larger and sizing is more effective to reduce coating penetration than those of KP sheet. With regard to pigment type, clay is more effective than calcium carbonate for better coating holdout.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.31 no.2
• /
• pp.34-41
• /
• 1999

Adsorption of cationic polyacrylamide dry strength resins onto the surface of papermaking fibers and fines is critical for their effective utilization. Since dry strength resins are frequently employed when recycled fibers containing a great deal of fines are used as a raw material, their adsorption characteristic onto the recycled fiber fines is of great importance. In this study, effects of recycling on adsorption characteristics of cationic polyacrylamide onto primary and secondary fines were examined. Never dried bleached hardwood kraft pulp was beaten and dried for recycling. In each recycling step the adsorption characteristic of a cationic PAM onto primary and secondary fines was evaluated by kjeldahl nitrogen analysis method. The influence of recycling on water retention value and carboxyl content along with the sheet density and tensile strength was examined. Secondary fines of never dried pulp adsorbed twice as much of C-PAM as the primary fines, however, the adsorption capacity of the secondary fines decreased rapidly during the course of recycling and showed lower adsorption capacily than primary fines.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.40 no.2
• /
• pp.1-7
• /
• 2008

The trend of using more hardwood and recycled fibers, and closing more tightly of the paper mill white water system has resulted in build-up of fines as well as organic and inorganic contaminants in the white water. This changes in papermaking wet end requires developing chemical additive system that provides good fiber retention and drainage in closed white water system. In this study the effect of charge densities and chemical characteristics of microparticle systems consisted of cationic guar gums and anionic colloidal silica sols on drainage and retention have been examined. Results showed that higher charge density of cationic guar gum and anionic colloidal silica sol gave better retention and drainage. Particularly highly structured silica gave greater retention efficiency.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.36 no.2
• /
• pp.1-9
• /
• 2004

Structure and strengths of paper have been studied by analyzing fibers characteristics depending on refining methods. In those studies stock preparation aspect of softwood and hardwood fibers mixing and fibers characteristics was focused for paper quality improvement. In this study drainage of fibers were analyzed to improve the production efficiency and paper product's quality. Fiber properties by one and two-step refining processes were compared. By applying two-step refining processes($2.8kg_f$ and $5.6kg_f$ of refining load), refining efficiency, drainage, and strengths could be improved at specific extent of refining.

• Journal of the Korean Wood Science and Technology
• /
• v.42 no.6
• /
• pp.635-645
• /
• 2014

The anatomical characteristics of eight major wood species planted in Indonesia were investigated to provide valuable information for their effective utilization. The growth-ring boundaries of Damar and Sumatran pine were indistinct. Resin canal was found in Sumatran pine but it was not observed in Damar. Cupressoid pit and taxodioid pit were found in Damar and window-like pit and pinoid pit were observed in Sumatran pine. Tracheid length of Damar and Sumatran pine was shorter than $3,000{\mu}m$. There were uniseriate rays in Damar and Sumatran pine and fusiform ray in Sumatran pine. All the hardwood species observed in this study were diffuse-porous. They had different vessel groups, i.e., solitary pore in Afrika and Simpur Batu, pore cluster in Angsana and mostly 2-4 rows of radial pore multiple in Mahoni. Mindi and Trembesi had mostly 2-3 rows of radial pore multiple with paratracheal parenchyma as aliform and confluent types. Afrika, Mahoni and Simpur Batu showed heterocellular rays which composed of procumbent cells in the body and mostly 1-2 rows of upright and/or square cells in the margin. All ray cells procumbent was observed in Angsana, Mindi and Trembesi. The large rays commonly exceeding 1 mm in height and ray width of 3~6 cells were observed in Simpur Batu. The other five hardwood species showed ray width of 1~3 cells. Vessel number per $mm^2$ of Angsana and Simpur Batu was higher than those of the other hardwood species. The length of wood fiber and tracheid showed a tendency to increase from pith to bark. By IAWA list, fiber length of hardwoods was classified into long in Simpur Batu and short in Angsana and Trembesi.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.47 no.1
• /
• pp.93-101
• /
• 2015

The purpose of this study is to examine the reusability of the fluff pulp recycled from paper diaper. To do this, the physical and optical properties of each handsheet made from these fluff pulp sample as well as the properties of the fiber recycled from paper diaper were analyzed and compared with those of non-recycled diaper fluff pulp samples and conventional pulp samples. These comparisons show that the characteristics of fiber such as length, width, curl, kink of the pulp recycled from paper diaper were similar to those of non-recycled diaper fluff pulp as well as to those of commercial pulp. The fine content of recycled diaper fluff pulp was lower than that of other pulp samples, while the ash content of the former was higher than that of the latter. Furthermore, it was also found that the bulk of handsheets made from the recycled fluff pulp was higher than that of other pulp samples, while the formation of the former was worse than that of the latter. The mechanical properties of the handsheet sample made from the recycled diaper fluff pulp was higher than those of the unused diaper fluff pulp and was lower that those of commercial fluff pulp and softwood tissue pulp handsheet. But, it was higher than that of hardwood tissue pulp handsheet. The optical properties of recycled diaper fluff pulp handsheet was lower than those of each handsheet samples made from other pulps due to its low fine content.