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Fine paper mill sludge (FPMS) disposal has emerged as a problem since the dumping of FPMS was banned. This study investigated the effects of adding a refined recovered lubricating oil (ion-refined oil) to FPMS pellets to increase its heating value and combustion time and decrease ash content and ignition time. Fuel pellets were prepared in three conditions, C-1, C-2, and C-3. In C-1, ion-refined oil was added to FPMS to examine its burning capability. In C-2, two types of pellets were produced mixing sawdust and FPMS ratios of 25:75 and 50:50. A ratio of 50:50 was selected for C-3, to which the ion-refined oil was added in different ratios. The quality of the energy fuel pellets was determined using proximate and ultimate analyses, except for chlorine content, which was determined through liquid ion chromatography. The properties of fuel pellets were determined and compared with national standards. It was confirmed that the results for pellets at a ratio of 50:50 with 10% and 15% ion-refined oil were acceptable, because these results were comparatively similar to the standards. Finally, it was concluded that ion-refined oil was an effective additive to FPMS to increase the heating value for energy demand and lower the ash content.

Defect spots degrade paper quality and often cause sheet breaks and other problems in the subsequent coating process. We encountered sporadic surges of defect spots on paper from a paper machine producing printing and writing grades of paper. We found that white or light-colored filler spots and waxy, translucent, elliptical spots accounted for 27.3 and 34.4% of these defects, respectively, and that both types of defect contained unhydrolyzed AKD as a major component. Paper machine’s wet-end deposits, however, did not contain unhydrolyzed AKD as a deposit component. We hypothesized that the colloidal stability of AKD was the main factor causing the increase in spot defects, and we verified this by deposit testing experiments. Among the papermaking additives tested, bentonite caused the most significant increase in AKD deposition during testing, which was attributed to its causing the electrostatic coagulation of cationically charged AKD emulsion particles. In contrast, anionically charged AKD emulsions showed improved stability and less deposit formation in the presence of bentonite.

Mottling within print-through and show-through is caused by the variability of the local optical properties of the sheet. This mottling is visually disturbing and a mark of poor paper quality. The ability to predict print-through mottle of printed paper by measuring show-through mottle on the unprinted sheet would be a valuable asset for paper machine control. We examined the relationship between print-through mottle and show-through mottle. We worked with nine samples of 60 lb. uncoated fine paper (90 g/m2), from various North American paper companies, that were printed on an offset press, 400K (400% Black), on both sides. A show-through mottle instrumental determination technique was developed using an existing Fast Fourier Transform-based algorithm. The nine samples examined were ranked similarly by the visual evaluation of print-through mottle and by the instrumental determination of show-through mottle. We thus established that show-through on the unprinted sheet can be used as a reliable predictor of print-through, therefore saving time and money for papermakers. We also found a significant two-sidedness in show-through for some of the samples.

Wet-end where the fibrous components and functional additives are applied is an essential part for determination of properties of the final product and runnability of papermaking process. However, it is difficult to anticipate physical and chemical phenomena in wet-end using some instruments for lab-scale papermaking test. In addition the performance of retention aids and fillers have to be evaluated by overall analysis of retention, drainage, and paper uniformity. With regard to renovate retention and drainage analyzer (RDA), a new analysis of retention, drainage, and paper uniformity using the RDA had been studied. In this study the RDA was modified by equipping air piston vibrator which could delay the consolidation of wet web and reduce the retention of fines. Effects of the varied kinds of fillers on wet-end of fine paper were analyzed by summation of drainage, turbidity (retention), and paper uniformity using the modified RDA. As a consequence, the selection of proper filler for the optimization of wet-end of paper making process for fine paper was made by using the modified RDA.

Full-scale anaerobic digestion processes for organic solid waste are common in Europe, but generally unaffordable in Canada and the United States because of inadequate regulations to restrict cheaper forms of disposal, particularly landfill. We investigated the viability of solid-state anaerobic digestion (SS-AD) as an alternative that reduces the costs of waste pretreatment and subsequent wastewater treatment. A laboratory SS-AD digester, comprising six 10L leach beds and an upflow anaerobic sludge blanket reactor treating the leachate, was operated continuously for 88 weeks, with a mass balance of 101±2%. The feed was a mixture of cardboard, boxboard, newsprint, and fine paper, and varying amounts of food waste (from 0% to 29% on a COD basis). No process upset or instability was observed. The addition of food waste showed a synergistic effect, raising CH4 production from the fibre mixture from 52.7 L.kg-1COD fibreadded to 152 L.kg-1COD fibreadded, an increase of 190%. Substrate COD destruction efficiency reached 65% and a methane yield of 225 L.kg-1 CODadded was achieved at 29% food waste on a COD basis, and a solids retention time of 42 days. This performance was similar to that of a completely stirred tank reactor digesting similar wastes, but with much lower energy input.Abstract Figure

Lignin is one of the constituent component of wood, but the presence of lignin can be a nuisance in the paper making process. Lignin will reduce the physical and optical properties of paper. The objctive of this study is to determine the advantages of lignin-kraft and its impact to modify cationic starch on the physical properties of fine paper. The study was conducted in steps. In the first step extraction was carried out to obtain the kraft-lignin, by using two extraction methode that is acid extraction with termal and acid extraction with centrifuge. Kraft-lignin was tested from both methods, the optimum test value will be continued at the coocking stage into resin-lignin. Resin-lignin will be a modified compound with level addition 3% and 6% of the dry weigh of cationic starch, then it will be applied to the handsheet with 13 variation, namely blank;, DS existing (2 Kg/TP, 4 Kg/Tp, dan 6 Kg/TP), cationic starch emultion + resin-lignin 6%, cationic starch substitution + resin-lignin 3%, and cationic starch substitution + resin-lignin 6%. Variation of cationic starch substitution + resin-lignin 6% at level addition 6 Kg/TP indicates the best value of physical strength. Especially on tensile strenght, wet tensile strenght, bursting, tearing, dan internal bonding value.

The saltwater immersion method was developed to inhibit mould growth on flood- or tsunami-damaged paper. Commercially available fine paper used for printing and writing showed decreased tensile indices after saltwater immersion. The salt remaining in the paper tended to increase the moisture content because of the salt deliquescence and moisture in the air. The tensile index was restored by removing salt from the paper. Crystallization and distribution of salt in interfibre pores were also considered to influence interfibre rebonding. The difference in the fibre responses to saltwater depended on the relationship between nano-scaled pores in the fibre walls, osmotic pressure, and the degree of sizing, which resulted in low water retention values. More of the starch applied as a surface sizing agent was dissolved or dispersed during distilled water immersion than saltwater immersion. This loosened the fibre network, which was a factor that decreased the sizing degree of the paper.

This article focuses on the properties of paper samples made using foam-laid technology. The effects of three surfactants, namely sodium dodecyl sulphate (SDS), sodium alkyl ether sulphate (SAES), and linear chain alkyl polyglucoside (C8/C10-Gluc), on properties of foam formed paper samples were studied, using chemithermo-mechanical (CTMP) spruce pulp and bleached kraft pulp. The results show that the type of surfactant used in foam forming has significant effects on the mechanical properties and quality of paper. In the presence of ionic polymers, the charge of surfactant has a significant effect on the formation of the paper sample. It was also shown that at AKD dosages ≥ 3 kg/t, the water absorbency of water formed paper samples was greater than that of foam-formed samples made using C8/C10-Gluc. Foam-forming also produced greater dryness after forming and wet-pressing than the water forming method. The type and dosage of surfactant had a significant impact on dewatering. Filler retention of foam-formed samples was significantly higher when using a non-ionic surfactant instead of an anionic surfactant. The effect of the strength additive (cationic starch) in increasing the strength of foam-formed samples was less in the presence of anionic surfactants than with non-ionic surfactants.

In this work the strength enhancing capabilities of microfibrillated cellulose (MFC) in highly filled papers was studied. Both the MFC production and the paper making were done in pilot scale under ...

Effects of artificial thermal aging on color variations of various commercial papers (fine paper, coated paper, newsprint and filter paper) were investigated. With thermal aging at 105 o C, most of papers showed a special trend in a * -b * plane: the a * (red-green) values of the samples were initially reduced (heading to a * side) and after a turning point they increased to +a * side while the b * (blue-yellow) values were kept increased to +b * side (yellowing of paper). Different papers had different turning points for a * value. The filter paper consisted of a pure chemical pulp and the copy paper with OBA (optical brightening agent) showed the latest turing points. In addition, the papers without OBA showed less reduction in brightness compared with that with OBA, suggesting that OBA could adversely influence the brightness stability during thermal aging. Keywords: Thermal aging, brightness, optical brightening agent, color differences, CIE L * a * b * 1. 서 론 종이가 제조된 후, 시간의 흐름에 따라 종이의 노화가 발생한다. 종이가 노화됨에 따라 종이의 물리적, 화학적 성질이 어떻게 변화하는지는, 종이의 보존 측면에서 또는 종이를 재생하는 측면에서 여러 연구자들에 의해서 연구되어져 왔다.

In order to explore new applications of recovered waste paper, we prepared electrically conductive fibers by plating waste newspaper pulp (WNP) fibers. Further, we mixed them with unplated WNP fibers and filtered the mixture to obtain a conductive pulp fiber sheet, which was to be used for electromagnetic compatibility (EMC) purposes. For the plating of WNP fibers, we used an electroless nickel plating method. We also plated pulp fibers recovered from fine paper, pulp fibers recovered from milk carton, and bleached softwood kraft pulp fibers, which were used for comparison with the plated WNP fibers. All of the four types of plated, recovered waste paper pulp fibers had high conductivity, i.e., an electrical conductivity of 0.1 S/m or more and a conductance of 0.02 S or more. The conductive pulp fiber sheet made of WNP fibers had an electric field shielding effect of 30 dB or more at 10–1000 MHz, provided that the ratio of the plated WNP fibers in the sheet was 40 % or more. Therefore, our conductive WNP fiber sheet is effective in EMC.

The aim of the study was to explain the transportation of liquid (fountain solution) during transfer to coated paper in the heatset offset printing process, together with the subsequent drying of the printed paper, by using statistical and experimental methods.A coating dispersion, applied as a single coating onto a fine paper substrate, was formulated using a narrow fine particle size distribution natural ground calcium carbonate pigment and a styrene acrylic binder. The moisture variation in the paper during printing was monitored by using online multipoint sensors based on near-infrared diffuse reflectance spectroscopy. Based on the results, a simulation model was created to determine the transfer of liquid thin films in the printing units, the evaporation in the printing units, followed by liquid absorption and evaporation in the heatset offset drying process. An accurate simulation depends on precise determination of the different process parameters that influence these factors.The absolute liquid/moisture amount transferred to the paper showed an increased trend as the paper passed through the application nips, though the proportion varied due to limited capillary absorption capacity properties of the paper. The background evaporation in the printing nips was evaluated with the simulation model as well as the drying stages in the dryer including surface and bulk condensation followed by rapid evaporation and cooling.

Silica is commonly used as an ingredient in the coatings of inkjet papers because of its capability to provide a coating layer structure combining a high pore volume, into which all the applied inkjet ink can transfer, and a suitable pore size distribution for very quick ink absorption. Nowadays, the production of silica pigment is quite expensive, and therefore, it would be advantageous to find a cheaper raw material source. In this study, the raw material was Greek olivine from magnesite mine sidestreams. The silica pigment was produced at laboratory scale by using nitric acid as a solvent. The target of this work was to clarify how this produced silica pigment is suited for inkjet coating pigments. The coating colors were applied by a laboratory rod coater on fine base paper and white-top kraftliner, and the coated surfaces were printed with a home and office area inkjet printer. The results showed that the produced olivine-based silica pigment has a potential in matt inkjet coatings. The coating of the produced silica pigment increased the print density, decreased the print-through, and diminished the bleeding of fine paper and white-top kraftliner board. However, further development work is needed to improve the pigment brightness to a more acceptable level, and to control the particle size at the nitric acid dissolution.

Poplar P-RC APMP was chosen as raw materials for fines generation and collecting, and then the P-RC APMP fines and calcium carbonate were co-flocculated before they were added into fiber fraction to make fine paper. Effect of different sub-fractions P-RC APMP fines and dosage of fines to make fine paper were studied. The result showed that, with the increasing of different sub-fractions fines dosage, the whiteness of paper increased first then decreased. For 200-mesh fines, 300-mesh fines, 400-mesh fines, the highest whiteness are obtained at 10%, 15%, 10% dosage respectively. Adding fines has positive effect on strength properties of paper. With the increasing of fines dosage, the strength properties of paper increased. Besides, the order of paper whiteness and strength is 400-mesh >300-mesh >200-mesh when using the dosage is same.

The efficiency of optical brightening agents (OBAs), also known as fluorescent whitening agents (FWAs), has long been of interest in the production of uncoated fine paper, particularly in uncoated fine paper grades containing high-yield pulp (HYP). The increasing levels of whiteness and also the increasing HYP substitution in fine papers has made OBA efficiency an important issue. This paper summarizes recent research findings in understanding and enhancing OBA efficiency in fine papers containing HYP, with focus on the main factors affecting OBA efficiency in both wet end and size press application. These factors include the base sheet brightness and whiteness of the pulp, UV competitors, OBA retention, quenching effects, and OBA migration at the size press. Some new technologies to improve OBA efficiency are discussed.

In recent years there has been an increasing interest in using high-yield pulp (HYP) as a partial replacement for hardwood bleached kraft pulp (HWBKP) in the production of high-quality fine papers as a cost-effective way of improving the product performance. This study investigated the substitution of HYP for HWBKP and its effect on the Alkenyl Succinic Anhydride (ASA) sizing performance. The results showed that the substitution of an aspen HYP for HWBKP can increase the ASA sizing performance at a HYP substitution as high as 15 to 20%. The ASA addition sequence has an influence on the ASA sizing performance and first adding ASA to the HYP followed by mixing with kraft pulps was the preferred method. Using precipitated calcium carbonate (PCC) as a paper filler at a dosage of less than 20% can increase the ASA sizing performance due to the contribution of the calcium soap of the hydrolysed ASA. A PCC dosage greater than 20% resulted in a negative impact on the sizing performance. It was also found that different PCC loading sequences can also affect the ASA sizing performance.

Increase of filler content in paper improves quality of the final product and reduces raw material costs. However, this is often accompanied by deterioration of paper machine runnability. In this paper the effects of stratifying PCC (precipitated calcium carbonate) and TMP on fine paper quality and the mechanical properties of dry and wet paper were studied. In addition, a new method was introduced for evaluating the layer purity of pulp and filler stratifying by measuring the fibre length distribution in the thickness direction of the paper. The filler addition reduced the mechanical properties of paper more with chemical than mechanical pulps, with similar dry tensile indices. Stratifying filler onto paper surfaces gave higher dry tensile strength properties than samples with mixed structures, whereas only a small positive effect was detected for wet tensile and relaxation properties as a result of stratifying. Stratifying fillers only had a small negative effect on the internal bond strength. Stratifying or mixing TMP with a chemical pulp blend was shown to enable an increase in the filler content of 10% without significant changes in the residual tension (tension after 0.475 s of relaxation) or tensile index of wet samples. Based on layer purity analysis, stratifying TMP and filler was found to be successful in these trials.

Cationized birch xylan was prepared and its use as a papermaking chemical was evaluated. The focus was on studying the effects of cationized birch xylan on the wet and dry strength of fine paper. The results of the laboratory experiments show that the addition of 3 percent of cationized birch xylan to birch kraft pulp improved the initial wet strength of the web by 30 percent compared to base stock at a solids content of 55%. Furthermore, the tensile stiffness of the wet web increased by approximately a third and the dry tensile strength improved by 26%, while the dry elastic modulus was not changed. The improvements in the strength properties were clear when compared to the base stock, but not as high as achieved with conventionally used cationized starch. The difference between the xylan and starch is most likely due to the shorter polymer chain length of the cationized xylan.

Eco-friendly high-yield pulps (HYP) are becoming increasingly used to product high value-added fine paper that is traditionally produced exclusively with chemical pulps. However, due to the presence of a large quantity of photosensitive lignin in the HYP pulp to more effectively utilize woods resources, there is a concern on the long term brightness stability of HYP containing paper. In this research, various TiO2was added to coating colors to improve the light fastness properties of HYP containing coated paper. The effect on the stability of optical properties of coated paper including brightness, opacity, color difference and the degree of brightness reversion before and after accelerated aging were studied. It was shown that the brightness stability of the HYP containing coated paper increased with increased addition of TiO2. Rutile TiO2was especially more effective than other types of TiO2on yellowing inhibition of coated paper. At a dosage of 3 parts of rutile TiO2, the brightness stability of coated paper containing 20% of HYP was found to be even better than paper made of 100% chemical pulp coated with conventional coating color.

Liquid transfer in a heatset printing process to coated papers has been evaluated online. The porous coatings, applied in various combinations of single coating onto a fine paper substrate, together with selective particle size distributions containing calcium carbonate pigments were calendered under different conditions to establish a range of porosities and pore structures while keeping the formulation and hence the surface chemistry constant. The transfer of fountain solution to the papers was analyzed from unprinted areas (nonimage) at six different positions along the printing line, namely, between each printing unit and after the dryer section, using near-infrared absorption reflectometry. In this way, real-time analysis of the amount of fountain solution (defined as water content) transferred to the paper per printing unit as a function of physical paper surface characteristics has been achieved. The role of printing speed and fountain solution dosage level on water uptake by the various coated paper substrates has been investigated. It was concluded that the higher the speed, firstly, there is less compression of the surface roughness and, secondly, less time for the liquid to respond with respect to capillary forces, resulting in less liquid transfer.

The yellowish color of High Yield Pulp (HYP) gives some psychological obstacles and limits its application in some paper grades. Dyes are widely used in the papermaking process to shade the yellowish color of the paper products. We proposed to add dyes into the HYP manufacturing process to minimize the yellowish hue. In this work, we substituted the dye-added HYP (dyes added in the HYP manufacturing process) for hardwood kraft pulp in the production of fine paper grades, and compared the results from those by adding dyes into the papermaking wet end. A higher dye effectiveness was obtained when we used the dye-added HYP. Also, the dye-added HYP gave more effective performance of Precipitated Calcium Carbonate (PCC) fillers and Optical Brightening Agents (OBA) in terms of CIE whiteness and b*. In addition, the dye-added HYP showed less negative effect on brightness and better compatibility with other dyes. The underlying mechanism for the above experimental observation was proposed.

Mill birch kraft pulp was fractionated using hydrocyclones and a pressure screen equipped with smooth-hole screen basket. Through hydrocyclone fractionation a coarse fraction was obtained having a high tensile stiffness and no extractives. The fine fraction had a high bonding ability and a high xylan and extractives content. The coarse fraction could be used in the top layer of board or in fine paper. The fine fraction obtained by hydrocyclone and pressure screen fractionation could be used for bonding in board middle layer or as a source of xylan. The tensile stiffness and Scott bond of the fractions could be improved further by optimized refining, using lower specific edge load and higher refining consistency.

後編では，4段晒法の採用によって高白色度パルプの製造に成功し，高品質の「広葉樹晒クラフト紙」の創製に至ったことについて述べたあと，この製法が何故洋紙の主流になり得たかに触れ，洋紙製造技術におけるその位置付けについて述べる。水野成夫氏，志村文三氏らは，用途が限られていたため当時未だ在積量が充分にあった広葉樹から，クラフトパルプを製造して製紙原料に利用しようと考えた。広葉樹は針葉樹と比較して繊維が短く，紙としては強度的に問題があるとの説が一般的だったが，彼らは「パルプの処理の仕方によっては良質の紙にすることが出来，強度以外の面でむしろ優れた特性を付与できる」と考えて挑戦した。幾多の困難を克服しての「創製」だが，クラフト法との組合わせは広葉樹の組成・形態から考えて誠に理にかなったものであった。紙の強度をもたらす繊維間結合の接着剤的役割を果たすヘミセルロースが広葉樹には多く，しかも繊維表面に比較的多く分布している。このへミセルロースはSP蒸解では多量に分解除去されるが，KP蒸解では除去され難いため，紙にした時の接着剤としての効果が大きい。そのため「針葉樹―SP」の紙と比べて，繊維自体は短くても紙としての強度は遜色なく，しかもその繊維形態ゆえに，地合い，嵩だか，こわさ，不透明性など今までの紙よりもむしろ優れている点が多かった。そのため印刷用途向けの「銀環」，包装その他加工用途の「KYP」の両銘柄とも市場の評価が極めて高く，その後この方法は国内の洋紙生産の主要製法となった。現在では世界的にも広葉樹は洋紙の主要原料である。針葉樹に比較して成長も早いことから，植林によって製紙原料の相当部分が賄われるようになっており，しかもバイオ技術の進展とも相俟って，紙パ産業は「持続可能な循環型素材産業」を目指して進みつつある。

Fine paper mills produce a variety of paper grades to satisfy demand for a large number of sheeted products. Huge reels of different paper grades are produced on a cyclical basis on paper machines. These reels are then cut into rolls of smaller size which are then either sold as such, or sheeted into finished products in converting plants. A huge number of roll sizes would be required to cut all finished products without trim loss and they cannot all be inventoried. An assortment of rolls is inventoried with the implication that the sheeting operations may yield trim loss. The selection of the assortment of roll sizes to stock and the assignment of these roll sizes to finished products have a significant impact on performances. This paper presents a model to decide the parent roll assortment and assignments to finished products based on these products demand processes, desired service levels, trim loss and inventory holding costs. Risk pooling economies made by assigning several finished products to a given roll size is a fundamental aspect of the problem. The overall model is a binary non-linear program. Two solution methods are developed: a branch and price algorithm based on column generation and a fast pricing heuristic, and a marginal cost heuristic. The two methods are tested on real data and also on randomly generated problem instances. The approach proposed was implemented by a large pulp and paper company.

High water consumption is a major environmental problem that the pulp and paper industry is facing. Ultrafiltration (UF) can be used to remove the dissolved and colloidal substances (DCS) concentrated during the recycling of white water (the process water) to facilitate the reuse of white water and reduce fresh water consumption. However, membrane fouling limits the application of UF in this industry. In this study, super-clear filtrate obtained from a fine paper mill was purified with a polyethersulfone (PES) ultrafiltration membrane to evaluate the reuse performance of the ultrafiltrate. The membrane foulants were characterized by scanning electron microscopy, energy-dispersive spectrophotometry, attenuated total reflection-fourier transform infrared spectroscopy, and gas chromatography-mass spectrometry. The results indicate that the retention rate of stock and the strength properties of paper increased when the ultrafiltrate was reused in the papermaking process compared to when super-clear filtrate was used. The reversible membrane foulants during ultrafiltration accounted for 85.52% of the total foulants and primarily originated from retention aids, drainage aids, and wet strength resins, while the irreversible adsorptive foulants accounted for 14.48% and mostly came from sizing agents, coating chemicals, and others. Moreover, the presence of dissolved multivalent metal ions, especially Ca2+, accelerated membrane fouling.

The impact of impulse technology on a system-wide level has been investigated in this study for non-integrated fine paper and linerboard mills. Impulse unit data were obtained from STFI's EuroFEX research paper machine and correlations were developed in order to predict performance (dewatering, electricity consumption) under commercial operating conditions. Mill analyses were conducted for different configurations (i.e. one or two impulse units with and without web preheating) operating with roll temperatures of 200–320 °C. Results show that the ingoing dryness to the dryer section can be increased within a wide span, from 7 to 27 percentage points depending upon the grade and operating parameters. Even though electricity consumption rises dramatically from the inductively heated rolls, overall fuel savings of up to 20% can be achieved with either one or two impulse units operating at 200 °C (external power plant efficiency assumed to be 45%). Impulse technology appears to be neutral in terms of production costs since increases in energy costs are expected to be counterbalanced by savings in feedstock materials and enhanced product quality. Estimates show that this technology can lead to substantial reductions in dryer section sizes for new installations or alternatively enhance productivity in existing paper machines.

For many years. retention-aid dosage has been controlled by the white water consistency in newsprint, fine paper and board applications. This control strategy is well known and has proven efficient and beneficial. However, combining retention-aid control and charge demand control with coagulant or fixative in the thick-stock area provides additional benefits. An on-line charge analyzer, measuring the incoming furnish charge level, allows controlled coagulant addition so that downstream additives are applied more efficiently and economically. This control strategy provides substantial cost savings to the mill. Costly functional additive consumption is reduced and other chemical control loops, such as retention-aid addition, are improved.This paper explains the impact of white-water consistency on paper machine outcomes such as basis weight variation, steam consumption and wet-end stability. White-water consistency, dewatering and charge demand control approaches are discussed, and practical examples are used to describe how short circulation and chemical composition of the pulp affects final product quality. Mill experiences with the on-line units, and proposed gains and benefits of these measurements to papermakers will be demonstrated.

At Yufutsu Mill. we produce 300 thousand tons of newsprint, fine paper, coated paper and cup paper each year by pulp plants (KP. TMP and DIP) and 5 paper machines. Wastewater from each process is discharged after purified at clarifier. In 2000, wastewater sludge was 7, 600 BDt per year. We started Refused Derived Fuel (RDF) production plant up in October 2000 to reduce the waste and use wastewater sludge effectively. Wastewater sludge has not been used as fuel because of its low low-heating value. We succeeded to make RDF from wastewater sludge to mix with wood chip made from waste pallet and waste core. This RDF is used for coal circulating fluid bed boiler as fuel. Hence it made possible to produce electricity from waste and steeply reduced wastewater sludge disposed of at landfill sites. This paper describes about an outline of our Refused Sludge Fuel System.

Increasing bulk is the first step toward resource-lean papermaking. Increasing the bulk tends to reduce strength and increase porosity and roughness; however, loss in strength could be compensated for via an increase in the specific strength of bonds. The increase in total surface area can have a positive influence on the porosity and smoothness of the paper. Results suggest that the bulk of fine paper can be increased by 20% and the critical paper properties maintained through selection of the kraft fibre type, control of the degree of hornification, addition of xyloglucan, and use of fines-rich mechanical pulp. In general, the results reported on here suggest that increasing bulk or reducing grammage is a challenging task but can be accomplished through simultaneous application of several unconventional measures.

The process to be applied to recovered paper to meet the quality requirements of recycled pulp is determined by the grade of the recovered paper and the demands of the final product. Roughly half of the total recovered papers are recycled for the production of case materials, mainly from old corrugated carton (OCC). Besides these brown recovered paper grades, white recovered paper grades, and some high-quality grades, are reused in newsprint, tissue and other graphic paper grades and in whip top layers of packaging papers, so these have to be deinked. Mixed recovered paper grades are used with OCC and for grey solid board layers and thus are not deinked. Deinking lines are more complex than OCC recycling lines. This is because in addition to the re-pulping and contaminant removal process steps, the pulp has to be deinked, and optionally bleached to achieve high brightness. Removing inks that are difficult to deink, like flexo prints and some digital prints, and ‘stickies’ from pressure-sensitive adhesives, are currently the main challenges in the field of deinking. Some examples of typical recycling and deinking lines for different applications – newsprint, fine paper, tissue, market pulp and packaging paper – are presented in this chapter.