• Title, Summary, Keyword: fines

Search Result 247, Processing Time 0.048 seconds

Impact of Fines Properties on Fiber Furnish Quality (미세분의 성질이 지료특성에 미치는 영향)

  • Cho Wook-Yeon;Seo Yung-Bum
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.37 no.2
    • /
    • pp.1-10
    • /
    • 2005
  • Removal of fines from fiber furnish by fractionation improves drainage, but decreases fiber bonding in paper. Fines can be again classified by their size such as the fines that passed 150 and 400 mesh screen, respectively. A hypothesis of different properties between these two kinds of fines was tested. Four different furnishes (SwBKP, HwBKP, KOCC, and BCTMP) were refined in two levels, and all their furnish and handsheet properties were compared in respect of their fines. KOCC fines gave the slowest drainage and least contribution to breaking length while BCTMP fines the fastest drainage and the highest contribution to breaking length. Removal of the fines that passed 400 mesh screen gave high improvement in drainage and large decrease in breaking length. Only KOCC fines removal gave more positive results where there were large improvement in drainage but only small decrease in breaking length.

Effects of Recycling on Adsorption Characteristics of Cationic Polyacrylamide onto Primary and Secondary Fines (리사이클링 횟수에 따른 일차미세섬유와 이차미세섬유의 폴리아크릴아미드 흡착특성 변화)

  • 주성범;이학래
    • 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.

  • PDF

Effect of fines on the compression behaviour of poorly graded silica sand

  • Hyodo, Masayuki;Wu, Yang;Kajiyama, Shintaro;Nakata, Yukio;Yoshimoto, Norimasa
    • Geomechanics and Engineering
    • /
    • v.12 no.1
    • /
    • pp.127-138
    • /
    • 2017
  • A series of high-pressure isotropic compression tests were performed on four types of poorly graded silica sand that were artificially prepared based on representative grading curves and similar mineralogy composition of seabed sediment containing different fines contents existing in the Nankai Trough. The addition of fines steepens the initial compression path and increases the decrement of the void ratio after loading. The transitional behaviour of the poorly graded sand with a larger amount of fines content was identified. The slope of the normal compression line shows a slight decreasing tendency with the level of fines content. The bulk modulus of silica sand with fines was lower when compared with the published results of silica sand without fines. A small amount of particle crushing of the four types of poorly graded sand with variable fines content levels was noticed, and the results indicated that the degree of particle crushing tended to decrease as the fines content increased.

The Influence of Pulp Fines on Paper Structural Characteristics (종이의 구조 특성에 미치는 미세섬유의 영향)

  • Lee, Jin-Ho;Park, Jong-Moon
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.38 no.4
    • /
    • pp.17-23
    • /
    • 2006
  • Paper has fibers and fines network structure and it is strongly affected by interface bond-ing between fibers. Paper structural properties can be determined depending on the inter-fiber bonding. Fines play an important role in Campbell and consolidation effect through wet pressing and drying operations. The fines are essential for the formation of bonds between fibers and for the improvement of strength properties of papers. Since the fines are components of the pulp, there are always two factors to be considered: the quality and quantity of the fines. The quality of fines might be a potential variable to give a more accurate picture of the papermaking potential of the pulp. The object of this study is to investigate the effect of different types of pulp fines on the properties of paper and to access the potential of fines for controlling the bulk of paper. Refined Sw-BKP, Hw-BKP and BCTMP fines were used to investigate the fines effect. Wet-web strength, breaking length, scattering coefficient, and hydrodynamic specific volume, and drying shrinkage were measured. According to the results, chemical and morphological compositions of fines do not strongly affect to wet-web forming by their similar Campbell effect, but strongly affect to drying operation which forms hydrogen bonding among fiber-fines-fiber matrixes. Paper bulk should be controlled by the extent of hydrogen bonding between fibers during drying operation.

Effect of Beating Time and Fines Content on the Drainage Properties of BKP (고해처리와 미세분 함량에 따른 BKP의 탈수특성변화)

  • 성용주;이학래
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.31 no.1
    • /
    • pp.52-60
    • /
    • 1999
  • Drainage rate in wet-end, which has significant influences on the production capacity, product quality and process economics in papermaking, becomes an important factor in the modern high speed papermaking processes owing to increased level of fines contained in today's pulp materials and increased papermaking system closure. A study was carred out to investigate the influence of beating and fines content on natural and vacuum dewatering using a vacuum drainage tester. Increase in beating and accumulation of fines in the stock decreased natural dewatering, Vacuum dewatering effect, however, increased substantially as beating and fines content were increased. But this increase in vacuum dewatering decreased again when a stock is severely beaten or fines content is greater than 35%. Above this level of fines content, mobile fines migrates to the interstices of the forming web to cause sealing or plugging which restrict fluid movement through the web.

  • PDF

Effects of fines content on void ratio, compressibility, and static liquefaction of silty sand

  • Lade, Poul V.;Yamamuro, Jerry A.;Liggio, Carl D. Jr.
    • Geomechanics and Engineering
    • /
    • v.1 no.1
    • /
    • pp.1-15
    • /
    • 2009
  • Many aspects of the behavior of sands are affected by the content of non-plastic fine particles and these various aspects should be included in a constitutive model for the soil behavior. The fines content affects maximum and minimum void ratios, compressibility, shear strength, and static liquefaction under undrained conditions. Twenty-eight undrained triaxial compression tests were performed on mixtures of sand and fine particles with fines contents of 0, 10, 20, 30, 50, 75, and 100% to study the effects of fines on void ratio, compressibility, and the occurrence of static liquefaction. The experiments were performed at low consolidation pressures at which liquefaction may occur in near-surface, natural deposits. The presence of fines creates a particle structure in the soil that is highly compressible, enhancing the potential for liquefaction, and the fines also alter the basic stress-strain and volume change behavior, which should be modeled to predict the occurrence of static liquefaction in the field. The void ratio at which liquefaction occurs for each sand/fines mixture was determined, and the variation of compressibility with void ratio was determined for each mixture. This allowed a relation to be determined between fines content, void ratio, compressibility, and the occurrence of static liquefaction. Such relations may vary from sand to sand, but the present results are believed to indicate the trend in such relations.

The Effect of Fines on the Property of High Yield Pulp (미세섬유(微細纖維)가 고수율(高收率)펄프의 지질(紙質)에 미치는 영향(影響))

  • Cho, Nam Seok
    • Journal of Korean Society of Forest Science
    • /
    • v.57 no.1
    • /
    • pp.14-19
    • /
    • 1982
  • Fines in high-yield sulfite pulp have much higher water retention value as compared with fines in Stone groundwood pulp. Therefore, they are apt to adhere partially or entirely onto the fiber surface during the paper making. This tendency is greatly enhance with decrease of the pretreated yield and increase of the water retention value of fines. Fines, which adhere onto the fiber surface in paper, contribute to the light scattering of the paper. Accordingly, the specific scattering coefficient of fines in high-yield sulfite pulp is considerably lower than that of fines in stone groundwood pulp, which hardly adhere onto the fiber surface. The fact that high-yield sulfite pulp is inferior to stone groundwood pulp in opacity is explained on the basis of the high degree of swelling of fined in addition to the softening of fiber fraction.

  • PDF

A Study on Strength Characteristics of Sand and Gravel with/without Fines (세립재의 유무에 의한 조립재료의 강도특성 연구)

  • Im, Eun-Sang;Snin, Dong-Hoon;Cho, Seong-Eun;Jeon, Jea-Seong
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • /
    • pp.827-830
    • /
    • 2008
  • In this study, large triaxia mpression tests of sand-gravel soils were carry out to clarify the influence of fines on shear strength characteries. Two soil specimens with/without fines that is used for construction material of dam were prepared. One was reproduced with wide range of grain size and the other was removed fines below 2mm from the one. The compaction tests proposed by our center were performed to obtain relative density of the specimens, and then each specimen was adjusted two dry density. The large triaxial compression tests were carry out under CD condition. Based on the results, the sand-gravel soils with low fines content has no effect on shear strength characteries.

  • PDF

Effects of Stock Characteristics on Paper Bulk

  • Lee, Jin-Ho;Park, Jong-Moon
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
    • /
    • /
    • pp.423-426
    • /
    • 2006
  • Paper has fibers and fines network structure and it is strongly affected by interface bonding between fibers. Depending on the inter-fiber bonding, paper bulk is determined. Fines play an important roll in Campbell and consolidation effect through wet pressing and drying operations. Refined Sw-BKP, Hw-BKP and BCTMP fines were used to investigate the fines effect. Wet-web strength, breaking length, scattering coefficient, and hydrodynamic specific volume were measured. According to the result of experiments, chemical and morphological compositions of fines do not strongly affect to wet-web forming, but strongly affect to drying operations which form hydrogen bonding among fiber-fines-fiber matrixes. Paper bulk should be controlled by the extent of hydrogen bonding between fibers during drying operations.

  • PDF

An Experimental Study on the Mechanical Properties of No-Fines Concrete (No-Fines Concrete의 역학적 특성에 관한 실험적 연구)

  • 홍건호;정일영
    • Magazine of the Korea Concrete Institute
    • /
    • v.6 no.3
    • /
    • pp.190-200
    • /
    • 1994
  • The purpose of this research is to examine experimentally the mechanical properties and economics of No-fines concrete for its application to the low-rise housing construction. Basic mechanical properties of No fines concrete are studied by measuring of compressive, tensile strength and stress-strain relationship, and economics of it is compared with other materials in unit cost and wall construction cost. From the test results, it can be concluded that No-fines concrete has advantages of good workability, light weight and lower construction cost, even though it has lower strength and modulus of elasticity than normal conc:rt:te does.