• 한국포장학회지
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• 제7권2호
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• pp.39-42
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• 2001

This study was carried out to research on the compression strength of paper cups and to investigate the possibility to recycle them as pallet blocks. The compression strength of paper cups was increased with the increase of the number of them showing the value between 0.5 and $5.9kg/cm^2$. The compression strength of the pallets using paper cups as the blocks was increased with the increase of the number of paper cups per block. Especially, the compression strength of the pallet with ten paper cups per block showed the value above 1000kg.

• 펄프종이기술
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• 제44권1호
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• pp.58-64
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• 2012

As a first step to apply PVAm (polyvinylamine) on packaging paper by surface treatment, three types of linerboards were impregnated with PVAm solution. The effect of PVAm pick-up on strength properties of linerboard was investigated. The pick-up of PVAm was controlled by varying concentration of PVAm solution. It was found that dry tensile strength, tensile energy absorption, burst strength and compressive strength of linerboard were increased by applying PVAm. In addition, wet tensile strength was significantly improved with increasing PVAm pick-up. However, folding endurance was found to be decreased with increasing PVAm pick-up.

• 한국인쇄학회지
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• 제30권3호
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• pp.35-43
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• 2012

Internal bonding strength of printing paper was increased with sea-algae pulp treatment. Spacially, 9% contents sea-algae pulp treatment in the hardwood pulp are more effective than in the softwood pulp. Most effective mixture ratio of the raw matrials for improvement of the internal bonding strength are softwood pulp 30%, hardwood pulp 70%, sea-algae pulp 9%. Internal bonding strength is effective in more sea-algae pulp contents and softwood pulp contents and wetness.

• 펄프종이기술
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• 제30권2호
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• pp.47-54
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• 1998

Refining is one of the most important processes of fiber treatment that provides optical and physical properties of final paper products. The evaluation method of refining progress is usually freeness (CSF) or wetness (SR) test because of its rapidity and convenience. However, there are some deficiencies in using freeness or wetness test to evaluate pulp fibers accurately because its results are more influenced by fines contents than extent of fibers treatment. The objective of this study is to show the deficiency of wetness in evaluating the refining process. For this, beating is done by varying the beating load. Handsheets are made after beating until 25 and $32^{\circ}C$ SR, and then paper properties are measured. Refined fibers are analyzed by fiber length, fines contents, curl, kink, WRV, and zero-span tensile strength. The results show that longer beating time is required to reach the same wetness at lower beating load. There are differences in the average fiber length, distribution curve of fiber length, fines contents, curl, kink, WRV of long fiber fraction, drainage time, and zero-span tensile strength of rewetted sample at different beating load. At the low beating load in the same wetness, apparent density, breaking length, burst strength, and tear strength are higher, while opacity and air permeability are lower than those of the high beating load. Using Page s equation, which shows the relationship among tensile strength, intrinsic fiber strength, and interfiber bonding strength, interfiber bonding strength is calculated and analyzed to explain final paper properties. At $25^{\circ}C$ SR, interfiber bonding strength is only slightly higher at 2.5kgf beating load, while the intrinsic fiber strength is substantially higher. At $32^{\circ}C$ SR, intrinsic fiber strength is a little bit higher at 2.5kgf beating load, and interfiber bonding strength is remarkably higher than those of 5.6kgf beating load. These results can be used to explain the different properties of the final paper at selected beating loads.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.1
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• pp.91-98
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• 2006

The purpose of this study is to investigate the opacity and printing strength of MG paper overlaid plywood. The printing strength of ink on MG paper can be evaluated effectively by a formula $E^{*2}=[(L^{*})^{2}+(a^{*})^{2}+(b^{*})^{2}]^{1/2}$ that we proposed. Higher E value indicates good printing strength of ink-on-paper. We also assess the real color of translucent printed MG paper with a formula CIE ${\bigtriangleup}E^{*}$ (color difference between a pile of same paper to be opaque and fancy paper laminated board). In addition, the color difference on paper surface caused by the color of wood-based board (bottom) can be evaluated by a formula of Pc. No. Generally, an acceptable appearance quality of fancy boards is ${\bigtriangleup}E^{*}$ <2.0 and small Pc.No. value. The experimental results showed that Japan-made MG papers -J1, J2 and J3 have better printing strength and gloss than that of Taiwan-made paper (T1). The reason for this was that Taiwan-made paper has poor printing strength and low gloss, which might be correlated to the fiber compositions in paper. Higher printing strength can be seen for short fiber containing handsheets when comparing to that of handsheets. Nonetheless, low-freeness sheets gives better printing strength than that of high-freeness sheets. High-opacity MG paper gives good opacifying effect to the fancy paper laminated wood-based boards. Comparing the surface color of 2 kinds of fancy paper laminated boards, paperboard T1 laminated with high-opacity fancy paper showed slight color difference. The same results can be seen for $??g/m^{2}$ handsheets. Higher-opacity Acacia and Eucalyptus bleached sulfate pulps (short fiber) gives higher opacifying effect on the plywood when comparing to Northan pine and Radiata pine sulfate pulps(long fiber). The former ones also showed small color differences when comparing the color differences between the color of fancy paper and laminated paper board. Additionally, the color of bottom plywood can't be shown through for the high-opacify surface paper adhered to. Besides, the PC No of the base paper laminated board is small as well. Apparently, we can add colorants to the binders for the manufscture of various handsheets ($30g/m^{2}$) with various pulp mix ratios to increase the opacity of paperboards to certain extents. When we using yellow and brown binders in paper laminated board, the color difference between Acacia and Eucalyptus handsheets overlaid boards decreasing to 2.0 (acceptable ${\bigtriangleup}E^{*}$ <2.0, hard to discern), but not much improvement for Northern and Radiata pines. Definitely, show-through defects can be discernible for lower opacity papers. In general, admirable printing strength of fancy paper by which glued to plywood can be made with high-opacity paper and colored binders techniques.

• 펄프종이기술
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• 제48권3호
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• pp.91-98
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• 2016

Linerboards have been produced by recycling recovered paper such as old corrugated containers(OCC). Usually linerboards produced during summer season show weak strength compared with those of produced during winter. In order to cope with the weak strength of linerboards produced during summer, and to confirm uniform quality, it is important to understand the seasonal effect on strength properties. Effect of pulping temperature of the OCC for linearboard production was investigated by controlling pulping temperatures at $18^{\circ}C$ and $51^{\circ}C$. Low pulping temperature ($18^{\circ}C$) caused more generation of fines in stock. Consequently retention and drainage of linerboard defibrated at high pulping temperature ($51^{\circ}C$) were better than those of $18^{\circ}C$. Strength properties of handsheet at low pulping temperature were higher than those of high pulping temperature and it could be confirmed that low pulping temperature during winter is one reason of seasonal variation of recycled linerboard strength. It is considered that surface modification of OCC fibers by harsh pulping action during winter caused increase of paper strength.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 방전 플라즈마 유기절연재료 초전도 자성체연구회
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• pp.87-93
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• 2004

Laminated Polypropylene Paper (LPP) and Kraft paper were used as ac power insulation for conventional cable as well as high temperature superconducting (HTS) cable because of its prominent insulating characteristics. However, researches on the use of LPP/Kraft paper in HTS cables are thinly scattered. In this paper, the effect of laminate polypropylene paper on the breakdown strength of LPP/Kraft multi-layer sample impregnated with liquid nitrogen (LN2)under ac and impulse applied voltage was studied. In addition, the breakdown strength characteristics of LPP and Kraft multi-layer sample were also investigated. It was found from the experimental data that the LPP has higher breakdown strength value than Kraft paper in ac and impulse. Especially in the ac case, the breakdown strength increases as the component ratio of LPP in the LPP/Kraftsample increases and slightly affected by the inserting position of LPP but in impulse case, the breakdown strength strongly depends on the number of LPP and the relative position of LPP.

• 한국인쇄학회지
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• 제7권1호
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• pp.49-59
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• 1989

This study was made to Investigate the effect of tensile strength(kg/cm$^{2}$), opacity(%), porosity(cc/min) of the paper manufacturing with the freeness properties of NBKP and the calcium carbonate having the different physical and chemical properties. As the results, the opacity and porosity of the freeness of, NBKP, obtained good strength properties from the freeness 65$^{\circ}$SR and the tensile strength from the freeness 85$^{\circ}$SR. The strength properties of paper manufacturing loaded with calcium carbonate appears to be related to the effect of the freeness, and it was obtained the good results at opacity 83.8% in the freeness 85$^{\circ}$SR, tensile strength 3.8kg/m$^{2}$ porosity 87cc/min in the freeness 65$^{\circ}$SR. Addition of 50%, 55%, 60% CaCO$_{3}$ was found to increase slightly the strength properties of paper.

• 한국구조물진단유지관리공학회 논문집
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• 제4권2호
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• pp.151-158
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• 2000

A study on the strength of steel tubular column filled with concrete under cocentrically compressed load is presented in this paper. This paper is structured as follows. The first section briefly discusses the M-N relationship formula derived for CFT, highlighting the additional moment effect. Next, the simple superposed method used to generate the strength formula of CFT loaded concentrically is described. In the final portion of this paper, the presented formula is compared to experimental data reported. The applicability of CFT strength formula presented here is limited somewhat by scope of concrete strength but can predict the strength of CFT simply and rapidly. The objective of this paper is to approach the strength of CFT theoretically and to examine the feasibility of presented formula.

• 펄프종이기술
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• 제47권4호
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• pp.60-65
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• 2015

In order to improve the strength of paper, mixing ratio of Sw-BKP and Hw-BKP and PVA (polyvinyl alcohol) fibers dosage were investigated. When the Sw-BKP fraction was increased, strength properties were increased because of average fibers length increased. When PVA fraction increased, paper strength was increased, but there was dissolution of PVA in water. The reason for improving handsheet strength that contained PVA was due to increased bonding action between the fibers by the PVA. The addition of PVA to kraft pulp would be helpful for packaging paper materials to increase strength and fracture toughness.