Uniform coating is a complex and difficult issue, as the coating process is affected by a large number of interrelated variables, ranging from the recipe, theology and application solids, to base sheet porosity and the unique characteristics of the coater. One key element for end coating homogeneity is control of the coating consolidation process. The ability to control the rate of evaporation requires continuous control of both air dryers and infrared (IR) dryers, providing the papermaker with a valuable tool to significantly enhance their product quality.
This paper presents a new method with a new developed GelView^TW sensor for monitoring and controlling the rate of drying coatings. The method consists of a series of fixed-point measurements, distributed along the path of the coater dryer section, configured to produce outputs enabling monitoring and control of the drying rate along the length of the coater. The individual measurements are presented in a standard operator station and track the reflective changes of the surface of the coating. The GelView is a fiber optic based system, which, through its complex algorithm, is capable of combining the surface condition data with other quality control data to produce a robust analysis of the drying rate of the coating. This new ability enables the papermaker to optimize production while minimizing or eliminating quality problems, such as back-trap print mottle.

View full abstract

We report new modified starch for improving surface strength of paper. Recently according to increase of waste paper, surface strength of paper tends to be lower, and at the same time printing press is operated more high-speed and has a function of multicolor printing for spread of offset printing, so that printing trouble is increasing such as picking, scuffing and break.
We have developed new amphoteric starch suitable for offset printing papers. This amphoteric starch shows more stable viscosity than commercial oxidized starch and has high water resistance on treated paper.
Size pressed paper with this amphoteric starch improves surface strength of paper.

View full abstract

Rotary Press Filter, a rotational pressurized dewatering machine with a new dewatering mechanism, which was introduced from Fournier Industries Inc. in Canada and is currently manufactured and sold by Tomoe Engineering Co., Ltd. Because of its high dewatering capacity, simple mechanism, sealed structure without odor, compactness that can reduce energy cost, and superior maintenance, Rotary Press Filter is considered to be a dewatering machine suitable for the future. We have installed 23 units (including sewage) and 3 units (2 places) for paper waste sludge only in Japan. In addition, we are continuously carrying out dewatering tests of various materials with a test machine and have obtained good results. In this report, I will introduce the test result of the continuous operation conducted for about three months at paper company A including comparison with other dewatering machines.

View full abstract

Sulfuric Acid, being used for additional ph adjustment of white water and adjusting ph in waster water application for a long time, is used for removing secondary products in proceeding Elementary Chlorine Free and Total Chlorine Free, and used as a part of substitute of Aluminum Sulfate for a cost saved assistant of sizing agent in Acid paper making and of reinforcing agent in neutral paper making. Aluminum Sulfate of having a purpose of ph adjustment is easy to handle and very popular chemical, therefore it had been added roughly to pulp making application but the cost is 2 or 3 times higher than 98% Sulfuric acid and it can be easily targeted for cost saving. Large cost saving will be made by substituting a part of Aluminum Sulfate.
Batch treatment is widely used for diluting Sulfuric acid but it should be changed to deeply considered safety method for human and environment as the application becomes wider. In meaning of safety method, we hereunder introduce our in-line diluting system.
Feature of in-line diluting system is high productivity because of easily and quickly manufacturing of whatever concentration and volumes in whenever needed. Moreover, storage tank is not required and space is saved, besides effect on human can be avoided.
Iwaki's Sulfuric dilution system has a unique design coming from various features being provided by pump maker. In-line mixing of using centrifugal pump was accomplished by using our own pump controller. Process time of the dilution becomes tremendously shorter and productivity becomes greatly improved. As the generated temperature varies by the concentration of dilution, we provide the best diluting method for each concentration for preventing the dilution from boiling and our using flexible tube absorbs heat expansion and contraction of piping. At the mixing point, siphon prevention function is employed and secondary safety function of checking valve failure is also employed. Besides, it also has a function of preventing convection caused by difference of specific gravity. For safety it has transparent plastic cover on piping units for accidental chemical spouting. Regarding system protection, our system has an alarm output in case of detecting flow rate variation (concentration change) , upper temperature limit (for piping protection) , upper and lower pressure limit (for piping protection) and abnormal works of motor driven valves (for piping protection) . Also our system as a protection program of stopping whole equipment in case of detecting a tripping of the pump inverter, thermal relay operation, wrong operation in manual operation and failure of sequence itself.
Since we do whole system controls of not only pump but also control devices and mixing unit by our experience of various kinds of diluting, we are very proud of offering the one year warranty on whole equipment.

View full abstract

This paper details the operational and economical impacts of upgrading from Cross-flow Lo-Solids® cooking process to DFLS™ cooking technology to produce more than 2000 ADMT⁄D of Kraft Hardwood pulp. Beginning in November of 2,000, Alberta Pacific has conducted several short and long term trials to determine if DFLSTM could benefit the digester operation by reducing the top three root causes for lost production in the digester area.
In the past, Alberta-Pacific Forest Ind. has experienced unstable plug movement in the digester vessel. This instability has resulted in difficulties controlling digester level, blowline kappa excursions and blowline temperature fluctuations. The blowline temperature fluctuations result in bypassing of the atmospheric diffuser, which is a critical washing stage.
The resultant benefits of DFLS™ mode of cooking throughout Brownstock, Bleach Plant and Chemical Recovery are also included in this paper.

View full abstract

Paper breaks are an efficiency robbing reality on all types of paper machines and coaters. Reducing breaks has become more and more important with the increasing speed and operating complexities of today’s paper and board machines.
Fully digital break recording technology, using the latest CCD cameras and digital image processing, is now offering papermakers new opportunities to find and solve the many reasons causing breaks. These systems continuously monitor, in real-time, all of the critical locations from the wet end to the dry end of the paper machine and coater. When a break occurs the system downloads the event into a permanent storage, making it possible to fully analyze what took place just before and after the break. This allows the papermaker to take the necessary corrective steps to prevent the break from occurring again.
Taking advantage of the latest technological advancements in digital image processing, these systems are now able to offer high image resolution, high reliability with minimal moving parts, and are able to provide automatic image analysis and alarming for holes, edge faults and sheet breaks.
These systems have now been proven on all types of paper machines, from the wet end to the dry end, ranging from slower board machines to the worlds fastest machines producing LWC, fine paper, newsprint, tissue etc.
This paper discusses the latest available techniques in camera break recording technology, their applications, and the results that have been achieved to date.

View full abstract

This paper describes the features and merits given by Yokogawa WIS and WIS roles in the MTS (Machine Technology Solution) . The system configuration of WIS is simple and keeps higher performance regardless of increase of cameras. WIS is good to maintain and reduces maintenance time and cost. Also WIS performs the automatic intensity control of light source and enables to extend a life span of light source. WIS has easy operator interface (defect map) for human feeling to accept. WIS provides various formation images such as displaying a reference beside of live formation, both sheet edge one. Regarding defects to be difficult to detect, WIS can detect water drops by transmission and lower contrast defects such as wrinkles, weak spots by SDI (Subtle Defect Image) technology. We introduce the overview of the advanced Auto Classifier which can classify automatically every kind of defect by applying neural network technology. Auto Classifier can create setting values and attributes to be needed to classify defects. WIS is easy to expand system and able to interface with our MTS elements such as ABS, MAS, QCS and so on.

View full abstract

By improvement in the speed of a paper manufacture machine, the increase in the used paper content in materials, etc., the dirt on the roller for paper manufacture has also increased from the second half of the 1980 s. The dirt on a roller caused increase of machine maintenance time, and the bad influence to paper quality, and the roller which cannot become dirty easily has been desired. Therefore, application of fluoro-resin coating roller started, and the appropriate effect was accepted. However, the low durability of the coating itself required the reproduction of the coating in the short period.
We started the development of the durable fluoro-resin coated roller to solve the problem, and development and released the composite surface treatment (Tiger roll and Jaguar roll) of the chromium plating and the fluoro-resin which will be mentioned later in 1990. After that we have been continuing the improvement of the resin itself and the design of composite surface with hard coating. And now in order for marked improvement to be accepted by these improvements in the performance.

View full abstract

This paper describes three new process modules developed to simulate the removal of ink from paper fibers and to predict brightness. These modules were used in the simulation of a newly constructed deink plant to predict brightness throughout the system. Model development and verification, as well as model application to the subject deink plant simulation, are detailed. The simulation was used to evaluate a disc thickener and a dynamic washer based on brightness gain and overall cost.

View full abstract

Landfill space limitations and rising disposal fees are creating opportunities for papermakers to increase recycled fiber usage. However, the recycled fibers rich with contaminants cause manufacturing difficulties when stickies cause deposits on papermaking equipment, thus necessitating paper machine shutdowns for cleaning. Paperboard manufacturers that use OCC fibers spend a considerable amount of money on cleaning chemicals to control contaminants.
This paper presents multiple case studies showing the effectiveness of a newly developed talc product for stickies control involving paperboard furnishes. A comparison with a chemical treatment is also included. The results demonstrate that the newly developed talc product provided the most cost-effective solution to the depositable stickies from recycled OCC pulps.

View full abstract

Horst Sprenger is one of the well-experienced Rod manufacturers in the world and has highest market share in European paper mills. The design concept is longer life, less trouble and excellent finishing of surface of paper and board.
The Rods and Beds are mainly applied for the following equipments : Auto Blade Symsizer (MESSO) , Speed Sizer•Roll Flex (VOITH) , Filmpress•Vari-Bar•etc. (JAGENBERG) .
Main applications : Sizing, Starch application, Pre- and top-coating for Board, Pigmenting, etc.
HS can supply both of plain surface rod and profile rod. Due to hydrodynamic pressure principle, coating can be achieved.
As to profile rods, coating weight can be varied by change of depth. All coating performances are of course depending on the following factors (Absorption, Colour solid content, Viscosity, Hardness of backing roll, Rod dia., Nip pressure) .
HS can offer the range of Rod dia. between 10 and 38mm. Plain Rods have generally chrome plating and HS also can offer ceramic coating Rods for longer life.
The materials of Beds are mainly PE and PU. PU has more elasticity and PE is stronger abrasion property. The future tendency of Bed material will be PE. Further, due to extrusion system, manufacturing cost of PE Bed will be reduced.
As to surface sizing, plain Rod is common use. For starch liquid application, plain Rod is not suitable. The profile Rod should be used for this application.
As to pigmenting, plain Rod with longer dia. is applied. The range of dia. will be between 20 and 38mm.
In order to minimize running cost, HS starts to supply “COMBI-SYSTEM”. The advantage of this system is to minimize cost of Rod Beds. The replace part is not complete Bed but only the part around Rod, which we call Rod Bed. We can expect to reduce the cost of Bed up to 50% or at least 30%.

View full abstract

Black liquor made in the kraft pulping process contains various surfactants derived from modified lignin. That means black liquor tends to make foam so easily that the process is troubled with foam at any time. If amount of foam was broken out, the efficiency of brown stock washer would decrease and the whiteness of pulp would be under the standard level. Furthermore, operation speed of brown stock washer would lower, which means the efficiency of pulp manufacturing would decrease. Though the foam trouble can also be prevented mechanically, chemical method using the defoamer is mainly adopted in the kraft pulping process. We present the characteristics of new silicone type defoamers, and their applications.

View full abstract

From elastic stress formulation obtained by previous paper, elastic stress analysis was performed for square Tubular case (CFBS : anisotropic panel) of corrugated fibber board box shape (width L, height h) under uniform compression p_y0. Then maximum values (σ_xmax, σ_ymax, τ_xymax) for normal stressesσ_x andσ_y to width and height directions and shear stressτ_xy were obtained by the formulation, and characteristic behaviour forσ_xmax, σ_ymax andτ_xymax were discussed. And maximum principal stressσ₁ and shear stressτ₁ were obtained and their maximumσ_1max andτ_1max were discussed.
σ_xmax is constant (ν_xypy0) for changes of Poisson’s ratioν_xy (effect to x direction deformation for y direction deformation) , L, h and x and y direction elastic longitudinal elastic moduli Ex and E_y. σ_ymax migrates from ranges of upper and lower edges to centers in upper and lower edges, and from their centers to panel plane centers with increases of L and h. τ_xymax migrates in narrow ranges about corners with increases of L and h. σ_1max migrates from corner vicinity to positions of distance h⁄8from upper and lower edge center, and from their positions to panel plane center vicinity. τ_1max migrates from corner to plane centers and next from plane centers to corners. σ_ymax, σ_1max andτ_1max increase and decrease slightly with L and h, and increase slightly with E_x andν_xy increases and decrease slightly with E_y increase. τ_xymax decreases and increases with L and h increases and increases withν_xy and E_x increases, and decreases with E_y increase.

View full abstract