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52 巻, 12 号
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大庭 諭1998 年 52 巻 12 号 p. 1655-1656
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーPDF形式でダウンロード (2710K) -
田中 浩雄1998 年 52 巻 12 号 p. 1657-1666
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーThe occurrence of charges on solid surfaces and the properties of electrical double layer were explained first, and some kinetic aspects on polymer additives in the wet-end were described.
Under turbulent flow conditions the adsorption of polymers on fibers and fillers is very rapid occuring in less than 1 second. The adsorbed polymers will reconform to a less expanded configuration which attains equilibrium state within 2-3 minutes. The reconformation process influences the flocculation efficiency of the adsorbed polymer. When the flocs are destroyed by the turbulence, the retained polymers can transfer between fibers and fillers, and the polymer chains can also be cleaved. The penetration of adsorbed polymers into fiber pores occurs very slowly.
It is possible that both the retention and the formation can be improved simultaneously, though the two are usually antinomic phenomena. But most of them are dependent on an ability of engineers at the paper mills.抄録全体を表示PDF形式でダウンロード (5196K) -
宮西 孝則1998 年 52 巻 12 号 p. 1667-1677
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーA laboratory system has been developed to measure simultaneously the zeta potential, flocculation, and drainage of pulp and filler suspensions under hydrodynamic shear flow. The magnitude and trend of on-line streaming potential measurements correlated well with off-line electrophoresis measurements. The slight deviation between two measurements showed the absorptivity difference of cationic chemicals with furnish components. The instrument was used to optimize flocculation and drainage for single retention systems and microparticle retention systems in a laboratory. Flocculation and drainage were affected by the order of chemicals, and the type of furnish. Drainage increases that occurred with the addition of bentonite were strongly influenced by charge neutralization.抄録全体を表示PDF形式でダウンロード (2856K) -
磯貝 明1998 年 52 巻 12 号 p. 1678-1686
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーFundamental mechanisms of paper sizing by internal sizes are reviewed on the basis of results obtained in our laboratory. Factors influencing paper sizing are explained in terms of basic theories of contact angles, changes in free energies, wettability, liquid-penetration and others. Recently, pyrolysis-gas chromatography techniques have been applied to determination of size content in paper, and thus sizing behavior can be examined in terms of size retention values. Pulp carboxyl groups and cationic compounds added at the wet-end have significant roles in size retention ; electrostatic interactions among sizes, pulp fibers and fines, anionic trashes, fillers and cationic compounds in pulp suspensions are the driving force of size retention, as well as physical filtration effects. Not only size retention but also distribution of size components and changes in chemical structures of size components affect sizing behavior. SEM obsevation of AKD-sized handsheets dried at 20°C, which had sufficient sizing levels, showed that most pulp fiber surfaces were occupied by hydrophilic cellulose and hemicellulose. Thus, complete coverage of pulp fiber surfaces with size molecules is not necessary for paper sizing, and distribution of hydrophobic size components on hydrophilic pulp fiber surfaces seems to govern the resultant sizing behavior. Solid-state 13C-NMR analysis of AKD-sized handsheets, extractions with either chloroform or 1% Tween 80 and SEM observations of handsheets prepared with AKD and ketone emulsions suggested that most size components were present as hydrolyzed structures without forming covalent bonds with hydroxyl groups of cellulose in paper. The structures of AKD and ASA, which can react with water and thus are somewhat hydrophilic, are necessary for paper sizing in order to avoid flocculation of the size components due to hydrophobic interactions on hydrophilic pulp fiber surfaces in papermaking process. This hypothesis of sizing mechanisms of AKD and ASA is applicable to other non-reactive sizes such as rosin soap, rosin acid emulsion and rosin-ester sizes.抄録全体を表示PDF形式でダウンロード (6899K) -
Redifloc と HCS を用いる三段階アプローチアンダーソン シェル1998 年 52 巻 12 号 p. 1687-1692
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーThe Compozil systems is a combination of a cationic polymer, BMB and an anionic colloidal silica, BMA. Compozil will enhance retention and dewatering on the papermachine without sacrificing paper formation. In the original Compozil system a cationic starch, BMB-TS is used together with BMA-0. A further development in this area was Compozil P system which contains a cationic polyacrylamide, BMB-PAM and a structured silica, BMA-780.
The Compozil technology has now been further developed in order to solve problems related to the usage of mechanical pulps and DIP/coated broke. By analysis of white water it was concluded that there are two main components in these pulps which causes problems ; firstly wood/white pitch and secondly acetate/calcium salts. Wood and white pitch give deposits and high salt concentrations/conductivity reduces the adsorption of cationic starch onto fibers.
To over-come these problems “A three step Compozil Technology” has been developed. Firstly, a specific polymer, Redifloc is added to the “pitch-rich” pulp and it will by a fixation mechanism decrease the pitch concentration and thereby reduce deposit problems.
Secondly, a high molecular weight polymer is selected. For woodcontaining-high conductivity systems a new starch has been developed, high cationic starch, HCS, which will adsorb much better onto fibers than ordinary starches (higher paper strength).
In the third step BMA is added to complete the Compozil flocculation. This will give high retention and dewatering at the same time without sacrificing formation. Another unique property of the Compozil is re-agglomeration on the wire. By dispersive forces on the wire repeatedly rearrangement of the flocs will take place which will ensure a uniform paper formation.
Today the Compozil technology includes three systems, which are used on around 300抄録全体を表示PDF形式でダウンロード (2210K) -
岡川 章夫1998 年 52 巻 12 号 p. 1693-1698
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーRecently new system of wet-end chemistry to increase retention and drainage of papermaking stock without deteriorating effect on formation has been introduced. The system uses (1) coagulant which acts as neutralization of surface charge of suspended materials, (2) macro-flocculant which acts as bridging fibers and other particles to form large floc, and (3) micro-flocculant which acts as bonding material to form micro-flocculation. Optimization of wet-end chemistry involves selection of best chemicals from the combination of all three agents or of any of the three. ECC International introduced the new concept on wet-end chemistry. Instead of using micro-flocculant which is normally inorganic micro-particles such as bentonite and colloidal silica, formation/drainage aid in the form of ligno-sulphonate is developed as the third component of Integra system. Ligno-sulphonate is used in many industries as dispersant, binder, stabilizer, complexing agent, etc. By selecting right molecular weight and anionic charge density (degree of sulphonation), dramatic effect on drainage and formation was demonstrated with a combination of ultra high molecular weight of cationic polymer flocculant. Several case studies on paper and board machines are presented.抄録全体を表示PDF形式でダウンロード (2209K) -
中島 正人1998 年 52 巻 12 号 p. 1699-1706
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーPolyacrylamide (PAM) and Starch have been widely used as paper strengthening agents. In particular, PAM has been preferably used for paper board production because of not only its excellent strengthening performance but also its advantage in paper-productivity with improving drainage effect and one-pass retention or in load-decrease of waste water treatment. In addition, the combined use of PAM in the starch-based system for paper production has been increasing to overcome the difficult requirement such as higher-speed printability etc, which are not achieved by starch-based system itself.
The current technological trends of PAM internal paper strengthening agents, concerning their mechanistic study, design concept and usage, are reviewed. In the concept of the strengthening agent, the relationship of the strengthening ability and some new design factors, chain structure (branch type) and ion distribution in PAM molecules, is introduced comparing with conventional design factors, molecular weight and ion type/amount. Such new concept are effectively applied to improve the quality of the strengthening agents for the current industrial situation, in which the use or mix of pulp from waste-paper often causes lowing the strength of the obtained paper, or the increase of ionic materials in white water due to closed water system causes inhibition of adsorption of the strengthening agents onto the pulp. In the usage of PAM internal paper strengthening agents, single PAM formulation and dual PAM formulation are introduced.抄録全体を表示PDF形式でダウンロード (2364K) -
榊原 厚1998 年 52 巻 12 号 p. 1707-1709
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーAbout 50, 000 tons per year of wet end starches is currently used by paper mills in Japan. The typical purposes are ; dry/temporary wet strength improvement, fines/ash retention increase, sizing agent retention improvement, drainage improvement, wet press picking reduction, improvement of flutability on corrugator. Such special features as paper machine cleanness and easy repulpability are attributable to starch, which consists of the same chemical unit, glucose, as pulp (cellulose).
Both by introducing not only quatemary cationic group but also an anionic group to starch backbone, and by balancing the two charges, new generation of amphoteric starches have been developed and used widely.
A big benefit of amphoteric starch is that the starch increases drainage whereas cationic starch tends to lower it. Another benefit is wet end stability and better runnability of paper machine ; i.e., overcationization is much less likely with amphoteric starch when stock condition changes than with a cationic starch.抄録全体を表示PDF形式でダウンロード (1621K) -
牧野 重人1998 年 52 巻 12 号 p. 1710-1716
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーSome applications such as tissue papers or filter papers require strength at wet even though paper orginally has weakness to water. For these applications, wet strength agents that meet such requirement are added to papers at the stage of pulp slurry.
Namely, we have polyamide resin or melamine resin for the additives that give paper strength at wet. The main reasons polyamide is suitable for the application are that it can give high wet strength with a little amount of the resin, it can be used in a wide pH range, and it does not contain formaldehyde. Melamine resin is also suitable for the application because of early appearance of wet strength after drying stage in papermaking, dimensional stability, alkali resistance, and ultraviolet-ray resistance.
Dry strength of paper largely depends on hydrogen bond among cellulose molecules. Invasion of water among fibers cause the destruction of the hydrogen bond. The wet strength expression mechanism of the polyamide resin apply to the prevention of water infiltration to fiber crossing made by crosslinked resin in drying process of papermaking. On the other hand, that of melamine resin apply to a strong water-resistant bond of methylol group in the resin between hydroxyl groups of the cellulose.
For the sake of effective usage of wet strength agents, we should keep the following important points in mind. First, enough heating is necessary for the expression of wet strength as wet strength agents are thermosetting. Secondly, since cation resin electrically interacts with anionic fiber, existence of anionic trash and salts decrease in the resin retention. At last, excessive addition of wet strength agents can cause decrease in the resin retention, pitch trouble, bubbling, increase in drain loading, and etc.抄録全体を表示PDF形式でダウンロード (2067K) -
渡辺 照雄1998 年 52 巻 12 号 p. 1717-1725
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーThe technology of papermaking is developing for improvement of paper productivity and quality, which requires the optimization of retention system at the wet end of paper machine. We evaluate the Polyionic Complex system that is one of the dual polymer mixture method for the wet end of paper machine to improve the formation and one pass retention (OPR). In this paper, we reveal the experience of the retention system applied for 3 PM which manufactures high quality coated paper, BW is 44 to 92 g/m2, and the machine speed is 800 to 1, 100 mpm. In this method, the optimal pH range is comparatively narrow between 5.0 to 5.5 and the flocculation is appeared at the isoelectric potential of chemicals (4.35.5). There is no effect for the paper quality and the strength except the internal bond strength, which improves more with concomitant use of cation starch. In has the broad ζ potential range around -4.8 to +3.7 mV, and no correlation with OPR. The OPR increases about 6% by this method and formation index increase about 3 point. This method contributes to improvement of the operation and quality for the acidic papermaking system. However, this method is inappropriate for the broke pulp arranged more than 30%, due to the calcium scale troubles.抄録全体を表示PDF形式でダウンロード (1209K) -
中村 茂1998 年 52 巻 12 号 p. 1726-1731
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーWith the purpose to improve main paper properties, the head-box of papermachine No 2 in the Iwanuma mill was reconstructed and the wire-part was remodeled to an on-top type in October 1996. Base paper for coating is produced on this machine and after the reconstruction paper properties such as two-sidedness, formation and ash profile were improved. However, at the same time one-pass retention (OPR) dropped resulting in some other quality and operational problems. After consideration it was judged that a dual retention aid system may be the most suitable way to over-come these problems to a reasonable chemical cost.
In January 1997 machine trials started with this dual retention aid system and in October the same year the machine went into comercial operation with this system. Sometimes paper formation is harmed by too high OPR. Therefore high OPR and good formation at the same time became an important issue. When the dual system was selected it was under the condition that formation would not be harmed and it was found that a microparticle system fulfilled this requirement.
After the introduction of the dual system remarkable improvements in operation and paper quality have been recognized. The chemical costs are also low and therefore we can conclude that all our targets have been realized. However some new issues have come up and we are now working to understand and solve these issues in order to further improve our situation.抄録全体を表示PDF形式でダウンロード (1884K) -
津野 誠一1998 年 52 巻 12 号 p. 1732-1737
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーPaper Technology Committee made a survey on wet end deposit of paper machines.They sent a questionnaire, on individual papermachine basis, asking information on deposit such as its locations at machines, components of deposit, cleaning systems during operation, estimated causes of deposit, and countermeasures and their effects. The committee received answers on 60 individual papermachines.
Most critical area is papermachine clothing such as forming fabric, wet felt, and dry fabric. Next to it are approach piping and screens. Countermeasure, while a machine is in operation, is improving washing efficiency with showers. Circulating caustic soda solution in a wet part is commonly used during downtime.
Many papermachine operators point out that alum which is one of common chemicals is an likely cause of the deposit. They also notice that the deposit trouble originating from recycled fiber is increasing as they use more recycled fiber. Frequency of cleaning with downtime is mostly from 2 to 3 times per month. Ten papermachines do it four times a month.
No definite difference on deposit trouble is discerned between acid and alkaline papermaking.抄録全体を表示PDF形式でダウンロード (1964K) -
太田 節三1998 年 52 巻 12 号 p. 1740
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーPDF形式でダウンロード (239K) -
喜多野 澄1998 年 52 巻 12 号 p. 1741-1749
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーAn image processing method to detect the position of a watermark is proposed. This is one of methods utilizing pattern matching techniques. One of its characteristics is to make a watermark in an input image included within limits of a reference image, whenever the reference image as a template shifts. Then, the position of a watermark in an input image can be detected by finding points where the convolution between an input image and a reference image has a maximum value, if all pixel values of the part except for a watermark in an input image are zero. The other characteristic is that a multi-level image is made by adding bi-level images after erosion.
After each of two bi-level images drawn by a computer, i. e. an input image and a reference image, was turned into a multi-level image, the convolution between these two multi-level images is implemented whenever the reference image shifts. Results of a computer simulation make it clear that the new method utilizing the convolution between two multi-level images makes the distribution of points where the convolution has a maximum value narrower than the conventional method utilizing the convolution between two bi-level images. Experimental results with an input image captured by an image sensor camera agree with those of a computer simulation. Therefore, it is found that the new method improves the precision of the position detection of a watermark compared to conventional methods.抄録全体を表示PDF形式でダウンロード (2585K) -
周辺支持・一様分布荷重の場合松島 理, 松島 成夫1998 年 52 巻 12 号 p. 1750-1760
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーAn elastic analysis of stress and deformation was performed for anisotropic rectangular plates of the single wall corrugated fiberboard (SWCF) supported by four edges under uniform loading. Relationships between maximum values for the deflection, support forces and stress components and parameters for the shape and the anisotropy of SWCF were discussed by this analysis. Obtained results are as follows.
Maximums of the deflection and support forces of four edges for SWCF plates increase with increases of length Lb and width Hb in the machine and the cross directions (MD and CD). Maximum σkxmax of the normal stress in MD on the surface of the kraftliner (KL) for SWCF increases with the increase of Lb in the range of Lb/Hb<1.0 and decreases in Lb/Hb>1.0, and maximum σkymax of the normal stress in CD increases monotonously with the increase of Lb. And σkxmax increases monotonously with the increase of Hb, and σkxmax increases with the increase of Hb in the range of Lb/Hb<1.8 and decreases in Lb/Hb>1.8.Maximum τkxymax of shear stress increases monotonously with increases of Lb and Hb.σkxmax decreases remarkably with the increase of ratio R (=Ekx/Eky) at longitudinal elastic modulus Ekx in MD to modulus Eky in CD for KL, and σkymax increases remarkably with the increase of ratio R. And τkxymax increases with the increase of R in the range of R<0.2 and decreases in R >0.2.抄録全体を表示PDF形式でダウンロード (2884K) -
蒸解廃液燃焼溶融物の処理方法及びクラフトパルプの製造方法原 普一1998 年 52 巻 12 号 p. 1761-1764
発行日: 1998/12/01
公開日: 2009/11/19
ジャーナル フリーPDF形式でダウンロード (949K)
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