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Volume 45, Issue 2
Displaying 1-14 of 14 articles from this issue
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Makoto Usuda1991 Volume 45 Issue 2 Pages 217-222
Published: February 01, 1991
Released on J-STAGE: November 19, 2009
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Kaneyasu Tani1991 Volume 45 Issue 2 Pages 223-227
Published: February 01, 1991
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSOverseas dependency on imports of paper/board by Japan is still low at 4%, while imports of pulpwood and pulp have reached 47% and 27% respectively. This paper explains that this has come about because of an excess in domestic production capacity, lower selling prices, uncertainties in the exchange rate and the differing quality requirements of the Japanese market, The author concludes that the Japanese industry should continues to proceed to eliminate such hurdles, which would otherwise result in the erosion of the market, thereby bringing greater benefits to the Japanese industry.View full abstractDownload PDF (4065K) -
Masaji Takizawa1991 Volume 45 Issue 2 Pages 228-235
Published: February 01, 1991
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSTechnology for the manufacture of unbleached and bleached pulps from hardwoods and softwoods is well established. With softwoods, the CTMP process offers significantly improved pulp quality profiles relative to those exhibited by mechanical pulp. In the case of hardwoods, the CTMP process offers a quality improvement from a low strength filler-type pulp to one capable of contributing significantly to overall sheet strength. Peroxide bleaching results in high brightness levels at reasonable peroxide consumption levels. In addition, alkaline swelling in conjunction with bleaching provides additional improvement in density and bonding properties, particularly in the case of hardwood CTMP.
Unbleached and bleached CTMP from both types of wood exhibits useful physical property profiles across a wide range of drainage characteristics. The pulp is already used extensively in a broad spectrum of products ranging from low freeness printing papers to high freeness absorbent grades. With the increasing price of fully bleached chemical pulps, there is growing interest in the use of bleached CTMP in printing and writing grades. While concerns remain regarding the brightness and brightness stability of lignified high yield pulps, these factors are not impeding the growth rate of CTMP.View full abstractDownload PDF (10900K) -
“New Recausticizing Process with Pressurized Disk Filter”Noboru Mimoto1991 Volume 45 Issue 2 Pages 236-241
Published: February 01, 1991
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSWe have delivered new recausticizing process with Pressurized Disk Filter (PDF) for the first time in Japan. Two PDFs are started up in the begining of 1990 and have been running successfully.
This report describes features and operating experience of this recausticizing process.View full abstractDownload PDF (2422K) -
A consideration by dimensional analysisA. Okagawa, F. Linhart1991 Volume 45 Issue 2 Pages 242-244
Published: February 01, 1991
Released on J-STAGE: April 23, 2010
JOURNAL FREE ACCESSSimple analogies and models help papermakers and chemists to illustrate the effects of process chemicals for their improvement and to obtain the best practical results. However, these practices are frequently not very realistic especially as far as the relative dimensions of components are concerned. If sizes of wood fibers, inorganic fillers and wet-end chemicals are magnified true to scale, surprising results are obtained, which yield valuable information on the mechanisms of these products.View full abstractDownload PDF (350K) -
The new mechanism of dry-strength development The concept of anionic and cationic polyacrylamide mixing systemTadashi Nagata1991 Volume 45 Issue 2 Pages 245-249
Published: February 01, 1991
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSThe application of functionalized polyacrylamide derivatives to paper strengthening agent (PSA) has gained wide acceptance by paper industry. The popular system of using these derivatives is the dual polymer system. In this system, the anionic-polyacrylamide is added to the pulp suspension after or before the addition of cationic-polyacrylamide. Recently, due to the effective utilization of recycled paper and the demand of various paper qualities, the PSA is required the quality improvement and more effective application. To satisfy these requirements, we established the new system of paper strength development, that is, the anionic-polyacrylamide and cationic -polyacrylamide mixing system. In the mixing system, different from the dual polymer system, the polyion complex is firstly made by mixing of anionic-polyacrylamide and cationic-polyacrylamide. Then, this mixed solution is added to the pulp suspension after the alum addition. Comparing with the conventional dual system, the mixing system gives much more improvement of pulp retention and paper quality. The investigation and application of the mixing system have been summarized.View full abstractDownload PDF (545K) -
Akira Uchida1991 Volume 45 Issue 2 Pages 250-255
Published: February 01, 1991
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSThe remarkable progress of paper coating and printing technology causes some problems as follows;
·decrease of paper gloss coated by high speed
·mottling trouble
In this paper the specially designed SBR latexes for high speed coating of high solid coating color and motting-free coated paper are discussed.View full abstractDownload PDF (3341K) -
Chisato Hamaguchi1991 Volume 45 Issue 2 Pages 256-262
Published: February 01, 1991
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSFrom the viewpoint of recent demand in light-weight-oriented or differentiated coated paper, organic pigments are attracting attention.
As for the organic pigments, there are polystyrene plastic pigments, and styrene-butadiene type plastic pigments (binder pigment latex) which were known from olden times, as well as styrene-acrylic hollow core pigments, and variety of odd-shaped particle pigments.
The writer would like to introduce the characteristics, concrete application examples, demand trends, and future prospects of these various plastic pigments in this paper.View full abstractDownload PDF (583K) -
Akira Yamada1991 Volume 45 Issue 2 Pages 263-268
Published: February 01, 1991
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSThe “mill-wide system of pulp and paper industries”, which improves the mill's overall efficiency, enable flexible production structure, save energy and so on, is introduced recently.
To realize it TOSHIBA developed C. I. E. Integrated system, which inter-actively combined production planning and management by Computer (C), process control by Instrumentation control system (I), and Electrical drive equipment (E).
In this paper, we describe the advanced technology of electrical drive (E) portion, and explain how conventional paper machine drive equipment has been changed to new hardware, that is adopted to C. I. E. integrated system.
Modern paper machine drive system is consist of fully digital drive equipment, high performance programmable controller based master controller, and operator interface stations for man-machine communication. This system achieves high accuracy control as well as improvement operation efficiency.
And also we explain the recent technical trend of AC drive systems, which adopt power transistor (GTR) and gate turn-off thyristor (GTO).View full abstractDownload PDF (3004K) -
Wood Science Committee JAPAN TAPPI1991 Volume 45 Issue 2 Pages 269-275
Published: February 01, 1991
Released on J-STAGE: February 22, 2010
JOURNAL FREE ACCESS -
[in Japanese]1991 Volume 45 Issue 2 Pages 276
Published: February 01, 1991
Released on J-STAGE: November 19, 2009
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Degradation of mechanical pulp containing paperRaysabro Oye, Takayuki Okayama, Hiroaki Matsubara, Katsuyuki Hanamura1991 Volume 45 Issue 2 Pages 277-284
Published: February 01, 1991
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSDegradation of book papers has been compared to a slow fire since decades and some conservation studies such as neutralization by diethyl zinc have been investigated. This paper deals with differentiation of papers from mechanical and chemical pulps by various accelerated aging tests.
Papers containing mechanical pulp, such as so-called semi-woodfree, wood containing, printing paper grade D and newsprint, showed no greater degradation rates in folding endurance and brightness at 105°C dry, 80°C -65%RH moist and repetition of 30% to 80%RH at 80°C recycling in 2 hrs interval accelerated agings compared with acidic and neutral woodfree papers.
When thermomechaniacal pulp was partially delignified with chlorine dioxide solution, handsheets from the pulps showed greater degradation rates with lower lignin contents.
According to color reversion tests under direct sun light, sun light through glass plate and fluorescence light, papers containing mechanical pulp exhibited significantly faster color reversion than in high temperature accelerated aging tests. The maximum color reversion at around 340 nm was observed by a monochromatic ultra-violet irradiation, however, no deterioration effect on folding endurance was observed at the above mentioned wave length.View full abstractDownload PDF (721K) -
Influence of pigment composition and calendering onliquid absorption of coated paperToshiharu Enomae, Fumihiko Onabe, Makoto Usuda1991 Volume 45 Issue 2 Pages 285-291
Published: February 01, 1991
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSPore structure of coatings is closely related to ink absorption in printing process. In the previous paper drying conditions and latex content were discussed as regulating factors of coating structure.
In the present paper influence of pigment composition and calendering on the liquid absorbency of coated paper were examined by Bristow's method and ultrasonic attenuation method.
Pigment compositions of coated paper samples prepared were altered by changing clay and calcium carbonate ratio with different particle shapes and sizes.
Conclusions obtained are as follows;
1.Absorbed water volume increased with the ratio of calcium carbonate which has largerparticle size than clay.
2. Total pore volume in coatings occupied with water could be calculated from Bristow's curve for the coated paper samples with the same smoothness as that of their base paper.
3. Calendering decreased the transferred liquid volume.
The reason for this finding may be that calendering leads to the smoothness improvement and compression of coatings that in turn made the pore volume smaller. However, that did not influence the absorption rate when water penetrated through the base paper layer.View full abstractDownload PDF (848K) -
1991 Volume 45 Issue 2 Pages 292-295
Published: February 01, 1991
Released on J-STAGE: November 19, 2009
JOURNAL FREE ACCESSDownload PDF (602K)
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