• 펄프종이기술
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• 제47권3호
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• pp.40-46
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• 2015

For some Korean newsprint mill, addition level of aluminum sulfate has been reduced because sulfur from aluminum sulfate has detrimental effect on the efficiency of anaerobic water treatment. At this moment, an unexpected decrease in sizing degree of TMP mixed newspaper was occurred. The phenomena means that hydrophobic substance usually originated from TMP cannot be fixed on the paper. This study focused on effect of alum and PAC on sizing of paper and contamination. Also, substitutability of PAC was discussed as a possible alternatives of aluminum sulfate under anaerobic condition of water treatment. Evaluation of sizing degree and pitch deposit potential were performed at the varied addition level of PAC and aluminum sulfate. Hydrophobic substance mainly derived from TMP could be fixed on the surface of fiber by PAC. Fines retention was not changed by replacing aluminum sulfate with PAC. Additionally, fixing of hydrophobic substance without excessive agglomeration can be enhanced by PAC with low molecular weight. Consequently, sizing degree of newspaper and contamination of recycling process of ONP can be controlled by low molecular weighted PAC.

• 펄프종이기술
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• 제46권3호
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• pp.11-19
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• 2014

Reliability of the novel automatic system capable of measuring both St$\ddot{o}$ckigt sizing degree and contact angle at a time was evaluated through the calculation of its repeatability and reproducibility based on TAPPI Standard Method T 1200. As the basis weight of paper specimen increased, the repeatability and reproducibility of the automatic system became more improved than those from Hercules sizing test and contact angle test designated on TAPPI Standard Method T 530 and T 558. The more improved repeatability and reproducibility implies that a single tester can obtain the similar results under similar test conditions in spite of repetitive testing using the automatic system, and likewise that multiple testers can respectively reproduce similar data without big variation from the same paper specimen using the automatic system. In conclusion, this study is greatly meaningful in having developed the world's first automatic system to measure both St$\ddot{o}$ckigt sizing degree and contact angle simultaneously with excellent repeatability and reproducibility.

• 펄프종이기술
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• 제36권1호
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• pp.1-8
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• 2004

One of the most frequently used method for measurement of the degree of sizing (viz., hydrophobicity) is the Stockigt test. However, the Stockigt test was influenced by various factors such as dropping height, dropping amount, dropping speed and viewing angle. The resultant data of the sizing degree on the same specimen also varied according to different testers. Thus, the Stockigt test should be modified to be regarded as a highly reliable and reproducible standard method. For modifying the Stockigt test, it was required to quantify red coloration by reaction between 1％ ferric chloride and 2％ ammonium thiocyante during Stockigt testing. The cameras capturing the serial images during the red coloration process were the CMOS (Complementary Metal Oxide Semiconductor)-type and CCD (Charge Coupled Device)-type cameras. For measurement based on KS M 7025, the CCD-type camera must be used due to its high resolution, and on the other hand, for measurement based on Tappi Useful Method 429, the CMOS-type camera may be used owing to its low resolution. It was needed to covert the RGB values of a droplet image into HSV(Hue, Saturation, and Value) values because the human eyes are much closer to HSV than RGB. Among HSV values, the Hue value was accepted as the most reliable index consistent with the red coloration process by excluding the surrounding conditions such as light, tester's movement etc.

• 펄프종이기술
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• 제30권2호
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• pp.24-29
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• 1998

This study was carried out in order to elucidate the deterioration mechanism of paper according to various sizing chemicals. No additive paper and four kinds of papers containing rosin-alum, alum only, alkylketene dimer(AKD)-cation polymer and cation polymer only were treated by UV light to study changes of water-resistant, optical and mechanical properties from the view points of natural deterioration of paper. Since rosin chemicals have UV absorption at the relatively long wavelength region, rosins are degraded to form hydrophilic groups such as carboxylic acid from their double bonds by UV treatments. These phenomena caused the decreasing of sizing degree and wetting time in case of rosin-sized paper, while the UV treatments brought about the slight increase of wetting time in rosin-free papers such as no additive, alum and kymene only paper owing to the auto-sizing effect. Optical properties were primarily influenced by sizing chemicals. Rosin-sized paper showed lower brightness after UV and near UV treatment because of its UV instability.

• 펄프종이기술
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• 제45권1호
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• pp.21-26
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• 2013

The influences of heat treatment and surface sizing on coating penetration were studied using two types of commercial base papers. Dry oven was used for heat treatment and laboratory rod draw down coater was used for surface sizing and coating application. Coating penetration was evaluated by measuring the roughness of the backside of coating layer. The backside of the coating was exposed by dissolving the fibers in a cupriethylenedimine(CED) solution. The results showed that both heat treatment and surface sizing were the effective methods to increase sizing degree and to reduce coating penetration.

• 펄프종이기술
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• 제33권2호
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• pp.17-23
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• 2001

AKD sizing behavior of handsheets, which were prepared from the different pulps with various AKD fixing agents, was studied in this investigation. AKD sizing performance could be improved by removal of fines in the stock, minimizing damage of fiber, using a suitable fixing agent and heat treatment. Fillers with low surface energy, like calcium carbonate and talc, showed quite positive effect in AKD sizing. When PAM was added to the DIP stock as fixing agent, it showed lower sizing degree than polyamine did. But in case of NBKP system, PAM was more effective than polymine.

• 펄프종이기술
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• 제35권5호
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• pp.17-25
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• 2003

The influence of base paper properties and fiber type on coating penetration was studied in terms of characterization of coating holdout using two types of hand sheets as the base paper which were prepared from thermomechanical pulp (TMP) and hardwood bleached kraft pulp(KP) sized internally with alkyl ketene dimmer (AKD). 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 (CEO). 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. From the result of water absorption and sizing degree after surface sizing, it seems that internal sizing slows down molecular diffusion much more than capillary penetration, but surface sizing reduces the capillary penetration. Furthermore, predominant mechanism of water into paper of TMP sheet seems to be capillary penetration, but it is molecular diffusion in the case of KP sheet.

• 대한화학회지
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• 제7권2호
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• pp.133-139
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• 1963

It is well-known that high temperature hurts the sizing effect of rosin size in paper making, mainly owing to the particle size of rosin-aluminium complex in paper stock. In this experiments, author find, when the temperature of stock rises up. the particle size of rosin-aluminium complex of neutral rosin size increases and the degree of sizing decreases finally. However, the behavior of Bewoid size is quite opposite to former. This result showed that, Bewoid size is suitable in hot summer and neutral rosin size in cold winter for better sizing effect.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1996년도 추계 학술발표회
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• pp.29-34
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• 1996

In the present paper, the flow distribution in the hot air drying chamber of a sizing machine was numerically analyzed with respect to the geometries of the intake duct to obtain the more uniform flow distribution in the chamber. The result shows that the velocity distribution in the inlet of the chamber was significantly dependent on the the geometry of the intake duct. The degree of the non-uniformity in the chamber was reduced as the incident angle of the intake duct became to be smaller.

• 펄프종이기술
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• 제41권5호
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• pp.1-7
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• 2009

Oxidized acetate starch was synthesized from corn oxidized starch and vinyl acetate. The sizing concentration and degree of substitution of modified starch on surface strength, smoothness and water resistance of the paper have been studied. The results showed that the surface strength, smoothness and other properties of paper sized by oxidized acetate starch is better than that of oxidized starch. When the degree of substitution of modified starch is from 0.04 to 0.14, the properties of paper sized by oxidized acetate starch have been improved more effectively.