• Journal of the Korean Wood Science and Technology
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• 제48권6호
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• pp.869-877
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• 2020

The power consumption in the low consistency (LC) refining is an important indicator for the optimal control of the process and it is composed of the net power and the no-load power. The refining efficiency and process characterization of LC refining are directly affected by power consumption. In this paper, the effect of pulp consistency and average fiber length on the power consumption and refining efficiency were studied through the LC refining trials conducted by an experimental disc refiner. It is found that the curve of power-gap clearance can be divided into constant power section, power reduction section, and power increase section. And the no-load power and the adjustable domain of loading applied by the refining plates will increase as the increase of pulp consistency, while the increase of net power is larger than that of no-load power which makes the increasing of refining efficiency. Meanwhile, the adjustable domain of loading applied by the refining plates can be slightly improved by increasing the average fiber length, but its effect on the no-load power in the LC refining process can be neglected. The study of power consumption in LC refining is of positive significance for the proper selection of pulp properties in LC refining, in-depth exploration of refining mechanism, and energy consumption reduction in refining.

• 펄프종이기술
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• 제36권2호
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• pp.17-23
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• 2004

The effects of refining consistency and plate gap on the specific energy consumption and physical properties of liner were investigated. Higher refining consistency and narrower plate gap brought about the reduction of specific energy consumption to decrease the freeness. Refining consistency and plate gap did not affect the bulk, Taber stiffness and compression index. The reduction of freeness and/or the increase of specific energy consumption caused the decrease of bulk and Taber stiffness, but increased the compression index. The effect of grammage on bulk was not observed, but Taber stiffness and compression index were increased with grammage. The bulk was decreased with the reduction of freeness rapidly at the above 400 mL CSF, and then levelled off. It is expected that the reduction of energy consumption could be obtained from the application of higher refining consistency and narrower plate gap during refining.

• 펄프종이기술
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• 제39권3호
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• pp.24-29
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• 2007

The stress and strain properties of KOCC were modified to improve the performance of KOCC as a packaging raw material. The refining consistency, refining degree, blending conditions and the grammage of handsheet were varied. The stress-strain properties, tensile energy absorption were measured. The refining improved significantly the stress and strain properties of paper, especially at lower refining consistency. The increase of grammage also contributed to the improvement in the stress and strain of paper. It was also found that the refining, blending and grammage contributed to the increase of tensile energy absorption. However, it is strongly recommended to apply the combination of refining consistency, refining degree and mechanical treatment(blending).

• 펄프종이기술
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• 제38권4호
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• pp.10-16
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• 2006

The study was carried out to investigate how the refining of pulps affects the stress-strain characteristics and physical properties of paper. SwBKP and HwBKP were refined with Hollender laboratory beater to obtain three levels of freeness(500, 400 and 300 ml CSF) at the different consistencies(0.5% and 1.0%). The effects of fines were also evaluated. The stresses and strains of papers made from SwBKP and HwBKP were increased with refining. The absolute value of strain in paper made from SwBKP was higher than those of paper made from HwBKP. We also found that the presence of fines increased the stress and strain significantly in both pulp types. The refining at lower pulp consistency gave higher stress and strain properties. Most physical properties of paper were improved with refining, but the effect of refining consistency depended on the characteristics of each physical properties.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.445-450
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• 2006

The stress and strain properties of KOCC were modified to improve the performance of KOCC as a packaging raw material. The refining consistency, refining degree and the grammage of handsheet were varied. The stress strain properties, tensile energy absorption were measured for prepared handsheets. The refining improved significantly the stress and strain properties of paper, especially at lower refining consistency. The increase of grammage also had contributed to improve the stress and strain of paper. It was also found that both refining and grammage contributed to the improvement of tensile energy absorption. However, it is strongly recommended to introduce the combination of refining consistency, refining degree and mechanical treatment.

• 펄프종이기술
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• 제36권3호
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• pp.44-51
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• 2004

The effect of refining conditions and grammage on the stiffness of linerboard was investigated. The correlations between Taber stiffness and resonance stiffness were very low due to the different measuring principle. The refining conditions did not affect sig nificantly on both Taber and resonance stiffness estimated here. This means that it is strongly recommended to find and apply the refining conditions which can reduce specific energy consumption. Taber stiffness showed very high correlation for the thickness and elastic modulus of linerboard, while the resonance stiffness showed much lower correlation. Effective thicknesses for Taber stiffness were very well fitted with measured thickness, while those for resonance stiffness depended on the grammage of linerboard.

• 펄프종이기술
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• 제36권2호
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• pp.10-16
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• 2004

Structures and strengths of paper have been studied by analyzing fibers characteristics depending on refining methods. Mixing ratio of softwood and hardwood fibers and fibers characteristics have been analyzed for paper quality improvement. In this study flocculation and drainage of fibers were analyzed to improve the production efficiency and paper product's quality. Floc size and drainage rate depending on stock consistency and fines content were analyzed. Total amount of drainage during drainage process was measured quantitatively by using DI(drainage index). Floc size, viscosity of floc and dewatering times were also measured. In the case of refining load $2.8 kg_f$ , drainage was occurred by filtration mechanism rather than thickening mechanism because drainage resistance increased by fibrillation of fibers. Therefore, the drainage rate of $2.8 kg_f$ refining load stock was slower than that of $5.6 kg_f$.

• Journal of the Korean Wood Science and Technology
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• 제48권5호
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• pp.581-590
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• 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.

• 펄프종이기술
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• 제39권1호
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• pp.1-7
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• 2007

Internal fibrillation of pulp fiber is an important factor affecting paper properties. Internal fibrillation of pulp fiber is usually introduced with several kinds of modifications of fiber by the mechanical treatment such as refining, high shear and/or high consistency mixing, etc. Unfortunately there are no standardized methods that can characterize the extent of internal fibrillation and its contribution on the paper properties. The purpose of this study is to try and find the potential methods that can characterize the internal fibrillation of pulp fiber quantitatively. Softwood bleached kraft pulp was treated with Hobart mixer to introduce the internal fibrillation without the significant fiber damage and external fibrillation. The extent of internal fibrillation was increased with the increase of mechanical treatment consistency. Several fiber properties were measured to find the potential means that could characterize and quantity the internal fibrillation. Laminated area could not be used as a means for quantifying the internal fibrillation because of the effect of swelling and the different internal fibrillation behavior at different mechanical treatment consistency. Micro and macro internal fibrillation models were proposed for describing the different behavior for the mechanical treatment at low and high consistencies of pulp. The Internal fibrillation showed good correlation with swelling of fiber wall. This trend was confirmed through the measurement of wall thickness and/or cross section area of fiber. Therefore the internal fibrillation possibly can be described as the indices indicating the change of wall thickness and/or cross section area.

• 한국의류학회지
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• 제46권4호
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• pp.704-722
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• 2022

Current studies validate the Body Positive Scale (BP Scale) as a self-assessment instrument that captures four dimensions of the positive body image construct. We developed and evaluated a 17-item BP Scale using two focus group interviews and four independent samples (n = 1,379) of Korean women who completed online survey questionnaires. We generated an initial pool of items via literature review, content validation with experts, and focus group interviews, subsequently refining the items through exploratory analysis (Study 1). We confirmed the BP Scale's underlying dimensions with young Korean female samples (Study 2, Study 4) and with a community sample (Study 3). We also examined the construct validity, internal consistency, and test-retest reliability over a six-week interval. Overall, the results supported that the four-factor BP Scale demonstrates adequate validity and reliability in measuring positive body image among Korean women. The BP Scale provides a method for researchers and practitioners to understand and assess individuals' positive body image in a multifaceted manner.