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Volume 51, Issue 6
Displaying 1-15 of 15 articles from this issue
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[in Japanese]1997 Volume 51 Issue 6 Pages 831
Published: June 01, 1997
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSDownload PDF (134K) -
Yoshio Kotani1997 Volume 51 Issue 6 Pages 832-841
Published: June 01, 1997
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSONP de-inked pulp manufacturing technology in Japan has been improving due to the changes in the nature of the raw material (specifically in the nature of the ink) and the wide variety of DIP applications.
With consistent demand for higher brightness and higher quality of the de-inked pulp, it is necessary to further improve the processing technology.
Therefore, we have included in this paper, comparisons of the process flows and the nature of the raw materials in Europe, United States, Japan and with the test results from our Pilot Plant. The process-flow for Japanese ONP is recommended.View full abstractDownload PDF (1274K) -
Takeshi Kanazawa1997 Volume 51 Issue 6 Pages 842-860
Published: June 01, 1997
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSIn order to protect global environment, save natural resources, and reduce production cost, use of deinked pulp has been expanded quite rapidly in various field such as news paper and printing-writing paper etc.. In recent years, recycling of printed fine paper including mixed office waste is attracting considerable attention, because of lack of raw material for the deinked pulp.
According to expansion of those raw material's recycling, many problems such as increase of difficult-deink papers printed by non-impact printing and UV ink etc., removal of sticky materials, ash and very fine dirt etc. and scattering of raw material's quality have been actualized.
This paper reports present problems for recycling of printed fine paper including mixed office waste, countermeasures for those problems, various deinking systems to meet those countermeasures and typical facilities to be used for the deinking systems.View full abstractDownload PDF (2672K) -
Kiyoshi Kokubun1997 Volume 51 Issue 6 Pages 861-867
Published: June 01, 1997
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSDomestic paperboard utilizes waste paper at the rate of 87.6% and this high utilizing rate has been achieved by the technical innovation of respective equipment in the stock preparation process.
Firstly, this paper reports chronologically the recycling process and its advancement, referring to our recycling process of waste corrugated fiberboard.
1) LIP System at the first generation (1975-1984)
2) UP/US Screen system and Hydrapurge at the second generation (1985-1994) 3) MFC/MF Screen system at nowadays
Then, this paper introduces the technical features and application examples of MF Screen, to which 1996's Sasaki Prize and Minister Prize of MITI have been awarded. The MF Screen united the screen with the defibering device, and achieved high fineness and low reject rate by elimination of internal cascades, resulting in the enhanced simplification of the screen system in the stock preparation process.View full abstractDownload PDF (597K) -
Takeshi Edo, Takanobu Shiroishi1997 Volume 51 Issue 6 Pages 868-874
Published: June 01, 1997
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSThe deinking of old news paper (ONP) has been practiced for several decades and recognized to be important in the meaning of environmental protection. Deinking technology has been progressing chemically and/or mechanically in production of high quality paper.
The deinking agents are the chemical species which are classified in surface active agent and have an important role during flotation deinking process such as penetrability, ink coagulation ability, foaming ability, and so on. By changing the molecular configuration of the deinking agents, we succeeded in developing a new deinking agent that has a higher penetrability. The higher the penetrability of the deinking agent, the lower the amount of nondetached ink. It is particularly effective against offset printing paper which is favored in the newsprint market in Japan. Furthermore, we could detect a direct evidence of interaction between ink and the new deinking agent by using quartz-crystal microbalance and photoacoustic spectroscopy. The new deinking agent is now in use at some deinking mills in Japan.
On the other hand, it is well known that flotation method is poor in removing fine ink particles, approximately under 10 μm. In spite of these particles strongly related to the products quality, they have little affinity for air bubble and making conventional flotation operations ineffective for ink removal. In order to remove the fine ink particles efficiently, it should be coagulated during the flotation process. Considering the problems associated with fine ink particles, we have developed a new type of deinking agent. In this report we also propose a new approach for ink coagulation method by flotation deinking.View full abstractDownload PDF (846K) -
Koichiro Fujiyasu1997 Volume 51 Issue 6 Pages 875-887
Published: June 01, 1997
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSWastepaper reclaimed for recycling can be classified to two categories. One, to which newsprint and magazine waste belong, contains lignin. The other, which is mostly fine paper waste, consists of wood free chemical pulp. The former is bleached with peroxides and reducing agents, and the latter is done by chlorine chemicals.
Recently, wood containing waste contaminates wood free waste, which causes troubles at bleaching with chlorine chemicals. Moreover, clorine chemicals are not favorable to environment. So, bleaching with peroxides and reducing agents is an alternative to it.
This paper describes characteristics of several bleaching agents such as chlorine and chlorine dioxide as chlorine chemicals, hydrogen peroxide, persulfate and organic peroxides as peroxides, and hydrosulfite, borohydride and thiourea dioxide as reducing agents. Then, practical systems for bleaching newsprint waste and fine paper waste are introduced respectively.View full abstractDownload PDF (1520K) -
Urban Svenson1997 Volume 51 Issue 6 Pages 888-891
Published: June 01, 1997
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSThe increased use of recycled paper raises new problems that require new solutions. The problems are magnified additionally if the deinking plant and the paper machines are closed to a high degree. Carry-over of chemicals from the deinking plant to the paper machine is an example.
Raisio Chemicals have, in cooperation with Åbo University and Braviken Paper Mill, developed a new and simple method for quantitative and qualitative analysis of fatty acids and saponified fatty acids in paper, pulp and white water. With this method it is possible to study how saponified fatty acids and rosins are separated in various process stages in a deinking plant.View full abstractDownload PDF (778K) -
Koichi Tabei, Shinkichi Kondo1997 Volume 51 Issue 6 Pages 892-894
Published: June 01, 1997
Released on J-STAGE: November 19, 2009
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Masakaza Monsanto1997 Volume 51 Issue 6 Pages 895-914
Published: June 01, 1997
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSAspects of the global utilization of nonwood plant fiber pulp are reviewed compared with that of woodpulp and waste paper, referring the data from FAO Yearbook 1994 and PPI July 1995. The ratio of nonwood pulp produced in the world attained to ca. 12% of all pulp produced in 1994. Characteristic differences between nonwood pulp and wood pulp, which are important to paper making use of them, are also reviewed on the point of morphological features of component cells and chemical composition of each pulp.View full abstractDownload PDF (3328K) -
Hiroshi Ono1997 Volume 51 Issue 6 Pages 915-919
Published: June 01, 1997
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSThe author had an opportunity to study at the Institute of Paper Science and Technology in Atlanta, Georgia for one academic year of 1996. IPST is the biggest pulp and, paper research institute in the United States whose charitable, educational, and scientific purpose evolves from the singular relationship between the Institute and the pulp and paper industry which has existed since 1929. In this report, mission of IPST, current research activities, and my impression of studying at IPST are reviewed.View full abstractDownload PDF (810K) -
Wood Science Committee1997 Volume 51 Issue 6 Pages 920-928
Published: June 01, 1997
Released on J-STAGE: November 19, 2009
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[in Japanese]1997 Volume 51 Issue 6 Pages 929
Published: June 01, 1997
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSDownload PDF (241K) -
Structural Analysis of Lignin by Pyrolysis-Gas Chromatography (V)Satoshi Suzuki, Hiroshi Ohi, Ken-ichi Kuroda1997 Volume 51 Issue 6 Pages 932-944
Published: June 01, 1997
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSPyrolysis-gas chromatography (Py-GC) is expected to be one of the useful methods for clarifying structural characteristics of lignin in mechanical pulps. In the structural analysis by Py-GC, lignin can be analyzed without being isolated from pulps. Papers which contain mechanical pulps are expected to be characterized by Py-GC. In this report, Py-GC was applied to the characterization of lignin in thermomechanical pulps (TMP) of softwoods and various kinds of papers.
Six species : akamatsu (Pinus densiflora), ezomatsu (Picea jezoensis), karamatsu (Larix kaempferi), spruce (Picea sp.), Douglas-fir (Pseudotsuga menziesii), todomatsu (Abies sachalinensis), which were used as raw materials of mechanical pulps, were analyzed by Py-GC. The eight main lignin-derived pyrolysis products (guaiacol, 4-methylguaiacol, 4-vinylguaiacol, vanillin, trans-isoeugenol, dihydroconiferyl alcohol, coniferaldehyde and trans-coniferyl alcohol) were detected. Comparing the pyrolysis products of woods, different yields of trans-coniferyl alcohol between the species were observed. Spruce and Douglas-fir showed high yields of trans-coniferyl alcohol, whereas akamatsu and todomatsu did low yields.
Py-GC was applied to the characterization of lignin in seventeen kinds of papers : printing and writing papers (wood containing paper, woodfree paper, and wood containing coated paper). Some pyrolysis products from lignin were detected in the analysis of several papers including mechanical pulp. Their characteristics of pyrogram suggested those of the mechanical pulp. Py-GC is more useful than other methods such as alkaline nitrobenzene oxidation because it provides more information on degradation products than alkaline nitrobenzene oxidation. Py-GC was found to be unaffected by filler in paper, while filler usually interfered with exact measurement of the Klason lignin. A kind of paper including hardwood mechanical pulp was clearly distinguished from the others by the detection of syringyl type pyrolysis products. It was considered that the higher yields of the pyrolysis products by Py-GC and the aldehydes by alkaline nitrobenzene oxidation showed the presence of mechanical pulps in papers in higher ratio. When a pyrogram of mechanical pulp is known, it seems to be able to distinguish the paper including the pulp from the others.View full abstractDownload PDF (1558K) -
Part 2 : A Novel Method for Imparting Electron-Beam Resistant Ability to PaperNaoichi Muto, Hidehiko Yamazaki1997 Volume 51 Issue 6 Pages 945-954
Published: June 01, 1997
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSIn this paper a novel method for obtaining electron-beam resisting paper is presented. As a method for obtaining electron-beam resisting paper we applied electron-beam reactive divinyl monomer molecules to paper so as to form the crosslinking between cellulose chains when irradiated. As the monomers, various diacrylate monomers with different molecular weights were used. The radicals produced on the fibers by electron-beam irradiation cause chemical reaction between electron-beam reactive monomer molecules and the fibers, and form grafts and crosslinks. Ethyl alcohol was employed as a solvent to impregnate the monomer molecules into micro-pores of the sheet effectively by lowering the surface tension and viscosity of the monomer solution. The pore size distribution, air permeability and bending moment of various original handsheets were conserved after the monomer impregnation and sheet drying. The physical properties of these handsheets were improved by the irradiation. It was found that the increase in folding endurance depends on the amount and graft ratio of the deposited monomer, and some monomer-impregnated handsheets show respective optimum monomer content for revealing the electron-beam resistant effect for strength properties.
Similar effects were also found for optical properties such as brightness and opacity.View full abstractDownload PDF (1337K) -
[in Japanese]1997 Volume 51 Issue 6 Pages 955-959
Published: June 01, 1997
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSDownload PDF (893K)
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