종이 기저귀로부터 재생된 fluff 펄프와 그 수초지 특성분석

최경화,조준형,김창근,이호선,류정용 한국펄프·종이공학회 2015 펄프.종이技術 Vol.34 No.1

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 ofeach handsheet samples made from other pulps due to its low fine content.

종이 기저귀로부터 재생된 fluff 펄프와 그 수초지 특성 분석

최경화(Kyoung-Hwa Choi),조준형(Jun-Hyung Cho),김창근(Chang Geun Kim),이호선(Ho Sun Lee),류정용(Jeong-Yong Ryu) 한국펄프·종이공학회 2015 펄프.종이기술 Vol.47 No.1

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.

원료의 배합 비율에 따른 펄프몰드 구조 및 흡수성 변화 연구

성용주(Yong Joo Sung),김동성(Dong Sung Kim),이주엽(Joo Yub Lee),백민석(Min Seok Baek),이지영(Ji Young Lee) 한국펄프·종이공학회 2018 펄프.종이기술 Vol.50 No.5

The effects of pulp types on the structure and the water absorption properties of pulp mold were investigated. The ONP (old newspaper recycled pulp), Sw-TMP (softwood thermomechanical pulp), Hw-BKP (hardwood bleached kraft pulp) were selected for this study. The pulp mold samples were prepared by using the laboratory wet pulp mold simulator. The pulp mold samples made with ONP showed lower bulkiness, lower Klemm water absorption property, lower maximum water contents and lower saturated water contents than those of the pulp mold made with Hw-BKP, which might be originated from the lower hydrophilicity and the higher ash contents of ONP. The addition of Sw-TMP increased the bulk and the water absorption properties of the pulp mold samples made with ONP. However, in case of the pulp mold samples made with Hw-BKP, the higher addition of Sw-TMP resulted in the lower Klemm water absorption and the lower saturated water contents. These results showed that the structural properties and the water absorption properties of pulp mold could be controlled by the raw materials depending on the fiber properties.

Effect of Combined Refining Plates with Different Bar Angles on Paper Properties during Mixed Pulp Refining

( Xiya Guo ),( Jixian Dong ),( Huan Liu ),( Chuanwu Duan ),( Ruifan Yang ),( Kai Qi ) 한국목재공학회 2020 목재공학 Vol.48 No.5

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 0°. 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 0° and 5° 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.

옥수수 줄기를 원료로 제조한 소다 펄프의 특성

송우용,이규성,이재성,신수정 한국펄프·종이공학회 2015 펄프.종이技術 Vol.38 No.1

Corn stalk is the lignocellulosic biomass, which remain as leftover after harvesting. To use the corn stalk as raw material for paper industry, soda pulping was applied. In chemical compositional analysis, extractive contents of corn stalk (45.1%) was higher than hardwood. With corn stalk pith, soda pulp yield was 25.3% at 10.6 Kappa number, but 39.5% yield with 14.8 Kappa number for corn stalk rind. Higher extractives content in pith is one of the reason for lower pulp yield than rind. Pith pulp fibers had higher fines content than rind pulp. Pith parenchyma cell was removed as fines during pulping or washing process, which caused the lower yield. To use the corn stalks as a raw material for paper making, de-pith process is essential for higher pulp yield and longer pulp length.

옥수수대 및 대나무 섬유로부터 제조된 셀룰로오스 나노피브릴의 특성

송우용(Woo-Yong Song),신수정(Soo-Jeong Shin),전소영(Soyoung Juhn) 한국펄프·종이공학회 2017 펄프.종이기술 Vol.49 No.2

Corn stalk and bamboo were used for raw materials for cellulose nanofibril by pulping followed by bleaching to compared with hardwood raw material. Corn pulp was produced by soda pulping process but bamboo pulp was made by soda-anthraquinone pulping process. Pulp yield was lower in bamboo (32.7%) compared with corn stalk (37.2%). Lower yield of bamboo pulp resulted in higher lignin content than hardwood, and more xylan removal in alkaline pulping. Lower yield of corn stalk come from higher hot-water extractives content than hardwood. Cellulose nanofibril (CNF) was made by bleached pulp with carboxymethylation pretreatment. Average width of CNF was 4.8 ㎚ for CNF from yellow poplar pulp, and 6.1 ㎚ from that of bamboo, but 16.5 nm for corn stalk pulp. Water-holding ability quite similar between bamboo CNF and yellow poplar CNF but quite lower for corn stalk CNF.

국내산 주요 죽종의 소다 및 소다-안트라퀴논 펄핑 특성 비교

이규성(Kyu-Seong Lee),송우용(Woo-Yong Song),신수정(Soo-Jeong Shin) 한국펄프·종이공학회 2016 펄프.종이기술 Vol.48 No.3

As a raw material for pulp and paper industry, Moso bamboo, Timber bamboo and Henon bamboo pulps were prepared by soda or soda-anthraquinone(Soda-AQ) pulping process. Soda–AQ pulp yields was higher in Henon bamboo (43.2%) than in Moso bamboo or Timber bamboo (32.7-39.2%), but quite lower than hardwood species. In Kappa number comparison, Henon bamboo pulp showed lower (16.6) with 50 min cooking to 170 ℃ than that of Moso bamboo (22.8) and Timber bamboo (18.9) with 90 min cooking to 170 ℃. Fiber length of Timber bamboo soda pulp had higher (1.46 mm) than that of Moso bamboo or Henon bamboo (1.18-1.36 mm). All three bamboo pulps showed longer average fiber length than commercial hardwood pulp. With higher pulp yield and lower Kappa number, Henon bamboo is better raw material for pulp than Moso bamboo and Timber bamboo.

Comparative Analysis of the Physical and Biochemical Properties of Light-cure Resin-modified Pulp Capping Materials

김태겸,김종수,이준행,신지선,한미란,김종빈,김유진,박재희 대한소아치과학회 2024 大韓小兒齒科學會誌 Vol.51 No.2

This study compared the solubility, water absorption, dimensional stability, release of various ions (hydroxyl, calcium, sulfur, strontium, and silicon), and cytotoxicity of lightcured resin-modified pulp-capping materials. Resin-modified calcium hydroxide (Ultrablend ™ plus, UBP), light-cured resin-modified calcium silicate (TheraCal LC™, TLC), and dual-cure resin-modified calcium silicate (TheraCal PT™, TPT) were used. Each material was polymerized; solubility, 24-hour water absorption, and 30- day dimensional stability experiments were conducted to test its physical properties. Solubility was assessed according to the ISO 6876 standard, and 24 hours of water absorption, 30 days of dimensional stability were assessed by referring to the previous protocol respectively. Eluates at 3 and 24 hours and on 7, 14, and 28 days were analyzed according to the ISO 10993-12 standard. And the pH, Ion-releasing ability, cell proliferation rate, and cell viability were assessed using the eluates to evaluate biochemical characteristics. pH was measured with a pH meter and Ion-releasing ability was assessed using inductively coupled plasma atomic emission spectrometry (ICP-AES). Cell proliferation rate and cell viability were assessed using human dental pulp cells (hDPCs). The former was assessed by an absorbance assay using the CCK-8 solution, and the latter was assessed by Live and Dead staining. TPT exhibited lower solubility and water absorption than TLC. UBP and TPT demonstrated higher stability than TLC. The release of sulfur, strontium, calcium, and hydroxyl ions was higher for TLC and TPT than for UBP. The 28-day release of hydroxyl and silicon ions was similar for TLC and TPT. TLC alone exhibited a lower cell proliferation rate compared to the control group at a dilution ratio of 1 : 2 in cell proliferation and dead cells from Live and Dead assay evaluation. Thus, when using light-cure resin-modified pulp-capping materials, calcium silicate-based materials can be considered alternatives to calcium hydroxide-based materials. Moreover, when comparing physical and biochemical properties, TPT could be prioritized over TLC as the first choice.

Effect of Ultrasonic-assisted Cold Caustic Extraction on the Properties of CTMP Poplar Fibers

Qianyu Sun,Guihua Yang,Jiachuan Chen,Ming He,Sipeng Niu 한국펄프·종이공학회 2017 펄프.종이技術 Vol.49 No.4

Chemithermo-mechanical pulp (CTMP) has been widely utilized in papermaking industry because of its high yield. However, the poor strength properties arising from the high contents of hemicellulose and lignin have limited its applications. In this study, ultrasonicassisted cold caustic extraction (CCE) on hemicellulose removal was applied to ascertain its influence on the properties of CTMP. It was found to have a positive effect on hemicellulose removal and resultant pulp properties. At the same alkali concentration (3 wt%), hemicellulose removal and Canadian Standard Freeness (CSF) in ultrasonic-assisted CCE (360 W, 10 min) increased 53.4% and 9.6%, respectively. Ultrasonic-assisted CCE reduces alkali concentration from 5 wt% to 2 wt% to obtain similar hemicelluloses removal, whereas the pulp yield at 2 wt% NaOH was higher than that of CCE alone at 5 wt% NaOH. In addition, at the same alkali concentration (3 wt%), the tensile index, bursting index and tearing index of CTMP in ultrasonic-assisted CCE (120 W, 10 min) increased by 12.7%, 11.34% and 3.0%, respectively. Ultrasonic-assisted CCE enhanced the fibrillation of fibers at optimal conditions, as determined by SEM.

Effect of sucrose and pectin addition on physical, chemical, thermal and rheologicalproperties of frozen/thawed pineapple pulps

Márcia Cavalcante Conceição,Tatiana Nunes Fernandes,Mônica Elisabeth Torres Prado,Jaime Vilela de Resende 한국유변학회 2012 Korea-Australia rheology journal Vol.24 No.3

Pectin (0-1.0g/100mL) and sucrose (0-20g/100mL) were added to pineapple pulp to improve their rheo\-logical properties, thermal properties and stability after freezing and thawing processes. The properties of the mixes were characterized before and after freezing and thawing. Samples were frozen at -20oC, and the freeze concentration was evaluated every 60min. The thawing rate was evaluated at 19oC and quantified by photographic editing and image analysis software. The thawing rates and values for the freeze con\-centration were leveled out at pectin concentrations above 0.5g/100mL pectin, which indicated that pectin functions to maintain structural homogeneity during freezing. In the thawed samples, the plastic viscosity values were leveled out from pectin concentrations (0.25-0.75g/100mL) as the sucrose concentration increased when compared to unfrozen samples. The differences between the rheological parameters of the unfrozen and frozen/thawed pulps, the higher yield stress values after thawing were attributed to the size of suspended particles in the pulp. Applications can specify formulations of frozen products containing pec\-tin, where these properties can be handled after thawing the product.