Search

The development of mathematical models that describe industrial processes is playing an increasing role in industrial context, because such models can replace, in some cases, experimental simulation, in a more inexpensive and flexible way. In this paper is presented a preliminary study of a transient model of a continuous moving bed reactor - the digester - used in the pulp and paper industry. In this complex and heterogeneous digester a moving bed of wood chips, containing cellulose, hemicellulose and lignin, reacts with sodium hydroxide and sodium sulfide - dissolved in a liquid phase - to remove the lignin from the cellulose fibers. The mathematical model studied here has been developed by Fernandes in a forthcoming Ph.D Thesis. The model is derived from the fundamental principles of mass and energy balance and is represented by a system of 15 partial differential equations (PDE) of convection-reaction type. The numerical methods used in the discretization of this PDE system are based on operator splitting which essentially consists in considering separately convection and reaction phenomena. This approach allows the use of methods with different properties - explicitness, implicitness and order - for each subprocess. The final global class of methods represents in some sense a “patching of tailored methods” well adapted to the feature of individual phenomena. Numerical simulations of the concentrations of organics and inorganics are presented.

Paper prototyping is a useful technique, but it is not perfect. This chapter outlines the kinds of usability problems that paper prototyping is likely and unlikely to find in an interface. It also discusses the kinds of problems faced in paper prototyping and describes some issues for which usability testing in general (whether paper or computer) is not the best means of discovery. Paper prototyping is a good technique. There are different ways to look at prototypes, but the most useful consists of four dimensions: breadth, depth, look, and interaction. Breadth refers to the percentage of the product's functionality that is represented in the prototype; Depth is the level of detail that's implemented including robustness; the Look is determined by inspection and is gives rise to the original concept of prototype fidelity; and Interaction refers to the way the prototype handles the inputs and outputs with the user. Time is an integral part of interaction, so things such as response time, cursor changes, flashing lights, and animation must be considered.

This Special Issue of the International Journal of Fatigue contains selected papers presented at the International Conference on Multiaxial Fatigue and Fracture held in Seville, Spain, on 1–3 June 2016.

Old newspapers Old newspapers (ONP), white blank newspapers Newsprint, boxboard, tissue, paper towels Old corrugated containers Old corrugated containers (OCC), double linerboard kraft corrugated clippings (DLK) Linerboard, boxboard, corrugating medium, kraft towels Mixed paper Mixed office waste (MOW), old magazines (OMG), sorted ledgers, computer printout (CPO), manifold white ledger (MWL), sorted office waste (SOW) Printing and writing paper, paperboard, tissue, paper towels, magazine newsprint

The enzymatic modification of cellulose, the major carbohydrate in different pulp fibres, offers unique opportunities for new applications, due to the different modes of action of individual cellulases. Although they all act on the same glycosidic β-1,4-linkage, different structural and functional modifications can be obtained depending on the type of fiber, enzyme and process phase used. Thus, cellulase based applications have been developed aiming at energy saving in refining, improvement of beatability, drainage and runnability of the paper machine, or enhancing de-inking processes. In these applications, the enzymatic treatment has been carried out on coarse or refined mechanical pulps, chemical pulps or recycled fibers at different phases of the processing. When applying cellulases, it is important to minimize the detrimental effects of these enzymes on the yield and strength properties of fibers. In this paper, the mode of action and effects of different types of cellulases; cellobiohydrolases and endoglucanases, are reviewed in the light of present applications.

In recent years interest in paper recycling has grown, as part of the increase popular awareness of environmental quality problems. Paper makes up about half of the weight of municipal refuse and municipal refuse disposal is an increasingly difficult problem. Landfill sites near large cities, which ofter the cheapest disposal method, are filling up at an increasing rate as the per capita solid waste generation continues to increase. Costs of acquiring more distant sites also continue to rise, as do transportation costs, hence reducing the total amount of refuse for disposal is of increasing economic importance aside from the environmental quality issue. This paper presents study-case with application of a linear programming model for production use and recycling of various paper and related products. This model is used to estimate the maximum feasible recycling rate given the current state of paper technology. Paper recycling, which is a very important issue in Brazil and many other countries.

1)Instituto de Recursos Naturales y Agrobiología de Sevilla, P.O. Box 1052, 41080-Seville, Spain; 2)ENCE-CIT, Ctra. Campañó, Ribeiro-Vao, 36157 Pontevedra, Spain; 3)Centro de Investigaciones Biológicas, Ramiro de Maeztu 9, E-28040 Madrid, Spain. E-mail address: delrio@irnase.csic.es (J.C. del Río), A set of Eucalyptus globulus woods from different origins and growth conditions, giving a wide range of pulp yields (from 40% to 60%) upon kraft cooking, was analyzed using Py-GC/MS. The carbohydrate-derived compounds and the compounds derived from syringyl (S) and guaiacyl (G) lignin units were analyzed and the lignin/carbohydrate and S/G ratios determined. Eucalypt woods giving higher pulp yield released higher amounts of S-type compounds upon Py-GC/MS. A significant correlation was observed between pulp yield and the lignin composition in terms of the S/G ratio. By contrast, the lignin/carbohydrate ratio obtained by Py-GC/MS, did not show a significant correlation with the pulp yield. This indicates that the lignin composition is a more important parameter influencing pulp yield than the lignin content., This study has been supported by Grupo Empresarial ENCE S.A. and the Spanish Ministerio de Ciencia y Tecnología (MCyT) (project AGL2002-00393). A.G. acknowledges a "Ramón y Cajal" contract of the Spanish MCyT.

Instituto de Recursos Naturales y Agrobiología, CSIC, P.O. Box 1052, E-41080, Seville, Spain E-mail address: delrio@irnase.csic.es, The composition of pitch deposits occurring in pulp sheets and mill circuits during soda/anthraquinone pulping and elemental chlorine-free pulp bleaching of bast fibers of industrial hemp (Cannabis sativa) has been studied. Pitch deposits were extracted with acetone, and the extracts analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Acetone extracts (15-25% of pitch deposits) were constituted by the defoamers used at the mill and by lipophilic extractives from hemp fibers. Acetone-insoluble residues (75-85% of pitch deposits) were analyzed by pyrolysis-GC/MS in the presence and absence of tetramethylammonium hydroxide. These residues were constituted by salts of fatty acids (arising from hemp fibers) with calcium, magnesium, aluminum and other cations that were identified in the deposits. It was concluded that inappropriate use of defoamer together with the presence of multivalent ions seemed to be among the causes of hemp extractives deposition in the pitch problems reported here., This study has been supported by the Spanish Ministerio de Ciencia y Tecnología (MCYT) and FEDER funds (projects 2FD97-0896-C02-02 and AGL2002-00393). A.G. acknowledges a "Ramón y Cajal" contract of the Spanish MCYT. We also thank CELESA (Tortosa, Spain) for providing the samples.

Recovered paper collection is increasing due to public interest and support. Four important grades of recovered paper include, corrugated boxes, newsprint, high grades like office papers and mixed papers. Recovered paper processing depends on the grade and product quality specifications. Some of the widely used processes and associated unit operations such as pulping, screening, cleaning using hydrocyclones, flotation deinking, dispersion, washing, and bleaching are described.

Publisher Summary This chapter elaborates the features of commercial paper (CP), which is a money market product and an important corporate finance instrument. Issuers of CP are often divided into two categories of company—banking and financial institutions and nonfinancial companies. There are two methods by which CP is issued: direct issued or direct paper and dealer issued or dealer paper. CP is a discount instrument, and hence is sold at a discount to its maturity value, and the difference between this maturity value and the purchase price is the interest earned by the investor. Although CP trades as a discount instrument in the United States and United Kingdom, Eurocurrency Eurocommerical paper trades on a yield basis similar to Certificates of Deposit.

The heat recovery system (HRS) is a vital part in a paper machine when it comes to the overall energy economy in papermaking. For a typical newsprint machine more than 60% of the exhaust energy from the dryer section can be recovered, resulting in a recovery of about 30 MW. The synthesis task of a HRS is a decision process where the target is on the one hand to achieve maximal energy recovery and on the other hand to obtain this recovery with minimal investment costs. These goals are contradictory and thus the problem is to find a solution minimizing the overall costs, considering simultaneously both energy and investment costs. This synthesis task can be performed with e.g. pinch-analyses or optimization methods. One of the first tasks for the designer is to decide which design parameters, including process flow streams, temperatures and heat transfer coefficients are to be applied. This task is in general not trivial and the result will have a great impact on the overall economy of the final HRS. One challenge is how to take into account uncertainties and known variations in some parameters. The desired design must be capable of handling all evolving situations but it should also be the most economical one when considering the duration of the different operational situations. In this work the importance of taking the variations and uncertainties into account in the design stage is shown with a case study.

The effects of retained wood resin and polysaccharides on paper strength, optical properties and fiction were studied. Wood resin, glucomannans and pectic acids were extracted from thermomechanical pulp (TMP). The wood resin was added in colloidal form to the fibre suspension and aggregated by the addition of cationic polymers or electrolytes. In part of the tests, polysaccharides were also added. Hand sheets were made and tested. The amounts of resin and polysaccharides in the sheets were determined by gas chromatography. The strength properties of the hand sheets deteriorated when the amount of wood resin was increased up to 2 mg/g. When the amount of wood resin was increased from 2 mg/g to 10 mg/g, only a slight decrease in strength properties was obtained. The static friction was lowered when the amount of wood resin was increased in the sheets. However, the optical properties were not significantly affected, even at high wood resin levels. When polysaccharides were added to fibre suspensions, together with wood resin, the strength properties were higher compared, at the same resin content, to sheets without added polysaccharides. Deacetylated glucomannans and pectic acids especially diminished the negative effect on paper strength caused by high wood resin content. Some of the polysaccharides were probably adsorbed onto the surface of the TMP fibres or wood resin droplets, which will increase the hydrophilicity of the surfaces, thereby promoting hydrogen bonds in the sheet. Aggregates of polymer and polysaccharides could also be retained in the fibre network.

Development in both paper and print technology are relative and complementary to one another. Meanwhile, printing technology has been on continuous improvement over the years in terms of ever-increasing machine speeds, finer image quality, and increased flexibility. Likewise, paper has followed the developments within the print industry to ensure that it remains a suitable substrate, capable of withstanding the rigors of modern printing processes. This is study focused on paper technology (which include papermaking and paper properties) and a classification of printing technology under three main types, which are: off-set lithography, laser/led (electrophotographic), and inkjet (thermal and piezo drop on demand) as these processes dominate the traditional and digital graphical printing market. Suitability of the printing technology is based on application as either of process has its merit and demerit.

It is important to produce and distribute foods in a safe and wholesome manner; the perishable nature of foods necessitates that their shelf life is prolonged by an appropriate packaging material. There is a continuous need to respond to consumers' demand for a safe and nutritious food with considerations to global environmental concerns. Consumers are increasingly demanding more information on the origin of their foods and their ingredients as labeled on their packages. The role of packaging materials in meeting these demands cannot be overemphasized. The use and production of paper packaging for food highlights the different types of paper and paperboards, their relevance to the circular economy, and environmental considerations.

A corrugated board is a paper sandwich construction made by combining three or more paperboard sheets. The paperboard used in corrugated containers is made from wood fibers, which can be recycled into new containers and other paper products. Based on target application, four types of corrugated board are manufactured namely: single face, single wall, double wall, and triple wall. And its main section of the corrugated board are: single-facer, storage bridge, double-backer, and cutoff–takeoff section. The pulp and paper industry is identify as leading industry of the world which contribute to municipal solid waste (MSW). Landfills remain the primary disposal method for MSW.

The paper product in security applications are type of papers designed and manufactured for a specific legal or monetary end-use for an organization or country. The value of the security paper is far beyond the cost of fabrication. This includes checks, bonds, banknotes, stock certificates, visas, passports, etc. This article focuses on currency (banknote) papers, one of the oldest forms of security papers, and how technological changes since 1960 have altered the course of the industry and determines the requirements of future security papers. Based on that, this study describes the end-use and history, properties, raw materials, manufacturing, finishing operations including printing, digital counterfeiting, machine-readable features and the future trends.

This section summarizes the major steps of continuous papermaking and the paper and board products produced, including commodity and specialty products. Paper usually undergoes some form of converting process, for example, coating and supercalendering, to produce the final product. The properties of paper and board are many and varied. The major ones being concerned with the mechanical, optical, dimensional stability, and printing properties.

Paper is one of the oldest forms of packaging material. Currently, paper and paperboard are the most widely used material for packaging applications, with the third largest market share in food packaging markets. Paper and paperboard are versatile. They, either alone or in combination with other materials, could be made into many forms of packages, ranging from paper label to drink box to corrugated paperboard container. This article provides an overview of paper and paperboard for food packaging applications, including a brief history and statistics on their production, consumption, waste management, as well as, related safety issues and regulations.

The electrochemically coated conducting paper based point-of-care diagnostics using amperometric sensing principles for troponin detection has been demonstrated in the present report. The cost-effective and stable conducting polymer coating was achieved on papers using screen printing followed by electrochemical deposition techniques for the first time. The cyclic voltammetric analysis has revealed the stable and uniform conducting polyaniline (PANI) coating onto filter papers fabricated using the simple and novel approach. These strips were found to be very sensitive for the futuristic diagnostics and the concept was proved by utilizing these strips for the troponin detection in a wide physiological range (1–100 ng/mL) with sensitivity of 5.5 μA/ng mL−1 cm−2. Association constant of the electrode has been found to be 1.2×1013 Lmol−1. Keywords: Conducting paper, Screen-printed electrode, Polyaniline, Biosensor, Troponin

An integrated investigation on wastewater characterization and the environmental effects from the COGIDO pulp and paper mill in Bien Hoa Industrial Estate, Vietnam, a chlorine bleached soda integrated pulp and paper mill operating without a chemical recovery system, on the receiving water body was conducted during the rainy and dry seasons in 1993 and 1995. The pollution load from the mill was very high in terms of BOD, COD and SS (CODm: 58.7t/d; BOD: 33.3 t/d and SS: 25.1 t/d). The effluent toxicity was determined using four toxicity tests: the green micro-alga, Selenastrum capricornutum, Microtox (marine bacteria: Photobacterium phosphoreum), the duckweed, Lemna aequinoctialis, and fish (silver barb: Puntius gonionotus, and Tilapia: Tilapia nilotica). Selenastrum capricornutum was the most sensitive among the tested organisms. The mill toxicity emission rate (TER) was as high as 338 610 (Selenastrum test). The bleaching-pulp and semi-chemical pulp plants which contributed the largest pollution load to the total COGIDO effluent, therefore, were targeted for abatement measures. Physicochemical parameters as well as qualitative and quantitative aquatic organism composition for the river water were established. The BOD5 and COD values exceeded the potable surface water standard by a factor of 2 to 4. The species diversity and abundance of the phytoplankton, zooplankton and zoobenthos were found to be lower (20–40%) than that of unpolluted rivers in Vietnam, whereas pollution-indicator species increased up to four times during the dry season 1995.

Publisher Summary Paper consists of a web of pulp fibers, usually formed from an aqueous slurry on a wire or screen, and held together by hydrogen bonding. The same basic steps are involved for either hand- or machine-made paper. The steps are: forming (applying the pulp slurry to a screen), draining (allowing water to drain by means of a force such as gravity or a pressure difference developed by a water column), pressing (further dewatering by squeezing water from the sheet), and drying (air drying or drying of the sheet over a hot surface). The paper machine is a device for continuously forming, dewatering, pressing, and drying a web of paper fibers. The most common type of wet end machine was the fourdrinier, where a dilute suspension of fibers is applied to an endless wire screen or plastic fabric. Water is removed by gravity, or the ΔP developed by table rolls, foils or suction equipment, and the drilled couch. The web at this point is 18-23% consistency. More water is squeezed out in the press section to a consistency of 35-55%. Finally the sheet is with steam heating in the dryer section. Modem paper machines can be quite expensive, costing up to several hundred million dollars each.

This chapter provides background information on the use of nonwood fiber in pulp and paper. Nonwood fiber is increasingly being used worldwide as a fiber source for papermaking. Annual plants have been used since the early 1800s, except for cotton. Straw has traditionally been pulped by boiling solutions of lime for board grades of paper; this led to a bright yellow pulp. Sodium hydroxide was used to make bleachable grades of pulp as well as board grades. The soda anthraquinone (AQ) method is replacing the soda method and the results of the soda/AQ for straw are said to be similar to those for kraft pulping of straw. Other methods of pulping include neutral sulfite and chlorine systems. Ash and silica both interfere with the pulping of many nonwood fibers. The cellulose, hemicellulose, lignin, and extractive contents are fundamental to pulping.

In this study, commercially available softwood lignin was esterified with tall oil fatty acid (TOFA) and studied as barrier material in fibre-based packaging material. The lignin was esterified to different degrees of substitution and the chemical analyses of the resulting samples were carried out by FTIR, TMAH thermochemolysis GC–MS, 31P NMR and SEC. After functionalization, the thermoplastic properties of the lignin were enhanced as shown by DSC. The novel thermoplastic lignin samples were applied with a bar coater forming an even coating on the paperboard substrate. The WVTR of the paperboard (840 g/m2 × 24 h) could be reduced to 260 g/m2 × 24 h with a TOFA lignin ester double coating of 3.9 g/m2. Furthermore, a decrease in OTR value was observed for the TOFA lignin ester as well as the TOFA coated paperboard samples. In contrast to the TOFA coating, the modified lignin coatings exhibited a high and stable contact angle (80° for 2 min). The coating material did not affect the tensile strength of the paperboard. According to the results, the demonstration of the conversion of lignin into a value added product has been shown. Furthermore, the novel coating material shows promising properties for the development as sustainable barrier material in fibre-based packaging material to replace oil-based barriers.

This chapter provides an overview of the pumps that are used in pulp and paper industry. In pulp and paper industry, high temperatures, very high suction pressures, low NPSHR requirements, poor lubricity, air entrainment, corrosive and acidic mixture of sodium or calcium bisulfite and sulfurous acid, and reliability are major considerations. The standard small process pump in pump and paper industry is the end suction, ANSI B73 or ISO 2858 chemical pump with centreline discharge open impeller and today more often than not mechanical seals. The larger pulp and low concentration transfer pumps are end suction, open impeller and adjustable wear plate, packing or mechanical seal type pumps with centerline discharge. Centrifugal stock pumps are used for consistencies up to approximately 5.5%, above this there are pumps with special internal features such as an inlet fluidizer that will allow consistencies up to as high as 18% consistency to be pumped. The pumps in the paper machine area are the screen, refiner, washer, cleaner and head box units as well as the refiner reject pump.

A study on toxicity discharges from three pulp and paper mills, two in Vietnam and one in Thailand, was conducted using the Microtox method, a rapid toxicity test with the marine bioluminescent bacterium, Photobacterium phosphoreum, as the test organism. Based on the EC50 values after 5 and 15 min of exposure, i.e. 5 min EC50 and 15 min EC50, respectively, the hypochlorite bleaching stage (H-H) effluent in the Thai mill was most toxic (EC50 were about 0.1% of the undiluted effluent) but still comparable with corresponding data obtained for COGIDO (0.4–0.5%). In BAPACO, toxicity of the effluent from the hypochlorite stages (H1 and H2) was much lower with the EC50 in the range of 38–83%. The chlorination (C) stage effluent in COGIDO with the 15 min EC50 of 18% was less toxic while the 15 min EC50 of this stage effluent was almost the same for both BAPACO and the Thai mill. The EC50 of the alkali-extraction (E) stage effluent were almost in the same range in all three mills. The combined effluent from the bleaching process was the most toxic in the Thai mill (EC50=0.4%), second toxic in COGIDO (8–10%) and the least toxic in BAPACO (14–24%). TEF (toxicity emission factors) values of this effluent show the same ranking: highest for the Thai mill (15000) followed by COGIDO with much lower TEF (1200) and the least was BAPACO (800). A less-than-additive, i.e. antagonistic, mode of toxicity was found for the combined effluent from bleaching plants and for various other combined effluents in the three mills. The bleaching plant is the largest toxicity source in terms of TEF in BAPACO, but not in COGIDO where the discharge of black liquor is the largest contribution of toxicity. For this reason, the total toxicity discharged from COGIDO with TEF>6000 was much higher than BAPACO with TEF of 750. For the Thai mill, the TEF of the pond system effluent alone was already much higher than TEF of the other two mills. Good house-keeping and process control improvement may greatly reduce acute toxicity from the mills.

Paper is a pliable material used for writing, packaging, and a variety of specialized purposes. Paper consists of a web of pulp fibers, usually formed from an aqueous slurry on a wire or screen, and held together by hydrogen bonding. Paper materials are classified as paper such as newsprint, stationary, tissue, bags, towels, and napkins, or paperboard such as linerboard, corrugating media, tubes, drums, milk cartons, recycled board used in shoe and cereal boxes, roofing felt, and fiberboard. Paper may be characterized by moisture content, physical characteristics, strength properties, optical properties, and other criteria depending on its end use. It is very important to obtain a sufficient number of representative samples by using a sampling procedure. When measuring strength properties MD refers to the test force applied in the machine direction CD is force applied in the cross machine direction. Paper properties depend on the orientation of the paper since the MD and CD properties are not identical. The MD of paper is parallel to the direction of travel during the manufacture of the paper; CD is perpendicular to MD. Paper properties such as tensile, fold, and compression vary significantly between these directions. This is often attributed to fiber orientation, but often of even more importance is the fact that in the machine direction paper is dried under much higher restraint than in the cross machine direction.

As do the other materials discussed in this book, food contact paper and paperboard enjoy (or are victim to) various systems of regulation throughout the world. In some jurisdictions, components of paper and paperboard must be included on a mandatory positive list of permitted substances; in certain jurisdictions, positive lists exist but are not legally binding. Other jurisdictions review a particular manufacturer’s substance on a case-by-case basis and confirm its acceptability for food contact use by way of communications, such as “no objection letters,” licenses, or notifications, which may be either mandatory or voluntary, depending on the jurisdiction and circumstances. In yet other areas, general standards applicable to food contact paper apply. The similarity between the different systems is that virtually all systems require that paper and paperboard must be safe for use in contact with food. Notably, in many jurisdictions throughout the world, this is the only requirement. This chapter will describe the systems currently in place for regulating materials used in food contact paper and paperboard in several areas throughout the globe. This is an ever-changing area of regulation, and many countries and regions are, at this moment, updating and further developing their systems. Thus, we capture here the state of food contact paper regulation at present, with the caveat that one should always seek to determine whether, and what, changes have been made, even over the course of just a few months.

The diagram constructed for selection of sampling methods indicates that, for a systematic error, E≤13%, grab sampling (GS) may be used to characterize effluents with variation coefficient of flow ≤120% and of contaminant concentrations ≤10%. For the whole studied range of variation coefficient of contaminant concentrations (2–82%), time-proportional compositing (TC) method may be applied with E≤10% for effluents characterized by variation coefficients in flow

Waste papers are recycled by deinking. All over the world, the flotation method is the mainstream as the deinking method because of the advantages such as higher pulp yield, less use of water, less area for installation and less total reagent cost. The flotation method is mainly consisted of pulping and flotation processes, the former for ink separation from cellulose, the latter for ink rejecting out from the system. Function to assist the mechanical separation of printing ink from cellulose is required for the deinking agent in the pulping process. In the flotation process, there are three particles, namely, ink, cellulose and bubble, and main four interaction between them in the flotation cell. The following relationship must be held to reject out the ink particles effectively. Vr0

Risks prevail at all libraries, which require disaster plans to protect employees, patrons, and facilities. Disaster plans should include measures for preparedness, response, and resumption. Emergency supplies should be available at all library sites. A sample response plan for a library describes what employees should do to stay safe during disasters. This plan covers risks such as fire, flooding, explosions, bomb threats, earthquakes, toxic spills, and severe weather.

The fundamental concepts, definitions, alternative expressions of species content in pore fluids and porous formations, and the mass, momentum, and energy conservation laws in multiphase and multispecies systems in porous media are presented. This background information is required in subsequent chapters for modeling of the various types of processes causing formation damage.

The transport of nuclear materials is strictly regulated and has an impressive safety record spanning six decades. Radioactive materials are designated “Class 7” and their safety in transit is achieved mainly by appropriate packaging, which must allow for accidents. Radiation exposure to those handling shipments and to the public need to be well within permitted levels. The security of radioactive materials in transport has received more attention since 2001.

Three advanced methods for controlling a paper machine wet end are presented: a) retention control, b) head box consistency control, and c) head box multivariable pressure and level control. All these methods improve the paper quality. These methods have been tested using an advanced data acquisition and control station. Some modern control algorithms have been implemented in the software package of the control station and it is possible to change both the control algorithms and their parameters on-line. A single-input single-output self-tuning controller (SISO STC) has been used for retention control on a production paper machine in a Finnish mill. A multivariable self-tuning PI-controller (MIMO SPI) having different sampling times for control and identification has been used for head box control.

Post-consumer paper, or waste paper, is an important, renewable raw material source for the paper industry and can contribute considerably towards reduction in its imports. Its recycling is also important from the environmental perspective, as systematic collection and recycling of waste paper can significantly reduce the generation of municipal solid wastes. Legal provisions on waste, regulating recovery and recycling of paper have become an essential framework for the paper industry. Legislation in various countries has attempted to promote material recycling and to decrease the waste generation that requires disposal in suitable facilities. In most developed nations, waste paper recycling is organised and operated by the municipal authorities, supported by suitable national policy normally based on the ‘polluter pays’ principle. Legislations are formulated in the form of directives, procurement policy guidelines as well as voluntary agreements. The collection mechanisms put in place are highly successful, as indicated by continuous improvement in the recovery rates of waste paper. These countries not only meet their domestic requirements but also export large quantities of waste paper. A few examples of such legislation are described in this chapter.

There is no reliable basic collection data available in most countries owing to the large number and various sizes of organisations involved in the collection of recovered paper. Normally, collection volumes are therefore calculated through recovered paper consumption and trade statistics. There are great differences in collection volumes and collection rates between countries. A few countries collect the main share of all recovered paper, globally. In 2006, the 13 most important countries collected 78% of all recovered paper, globally. These countries include the USA, Japan, China and Germany, which together collected 55% of all recovered paper globally. The collection of recovered paper is performed by (i) collection in private households and small commercial enterprises, (ii) collection from industrial and business operations sites where unwrapping is performed, offices, authorities and administration and (iii) returns of recovered paper from converting facilities such as printing houses and corrugated board industry and over-issues. Depending on the origin of the collected recovered paper, a clear difference exists between pre- and post-consumer recovered paper. Paper recyclers are developing new technologies designed to handle, identify and separate paper grades for recycling. One enhancement technology allows segregation of paper fibres during the recycling process according to fibre length, coarseness and stiffness through a sequential centrifuging and screening process. This chapter describes different types of collection systems, sorting, handling and storage of recovered paper.

Some recovered paper is utilised outside the paper industry for construction purposes, insulation, mailing bags and other end uses. In most of the countries, no accurate data is available to estimate recovered paper utilisation for applications other than the paper industry. In addition to use in the paper industry, over 8% of collected paper is used in other applications: construction materials, animal beddings, composting and energy. Recycling is considered better than composting in the hierarchy of materials management. In this chapter, uses of recovered paper other than papermaking are discussed.

A bioreactor, integrated with an anoxic reactor and a settler for waste water treatment from a paper production plant is under investigation to implement a control system for enhancing effluent quality. In order to reveal the operation of the integrated process to achieve a specific goal, a methodology for control system development is proposed. In this paper, preliminary results of some steps of the methodology are presented, in order to address the oxygen uptake rate control. A dynamic model is developed for future analysis for the conceptual design of different generated control configurations.

Paper in all its forms and applications represents a sustainable, renewable material serving many ingenious societal uses. Typically, utilizing nature’s biopolymer cellulose in natural fiber form originating from the cell wall of various wood species, paper and its adjacent technologies continue to evolve today providing efficient solutions in both routine and demanding end uses. A brief survey regarding paper and papermaking history is presented relaying the key inventions and steps forward in a centuries-old human essential. End application categories are discussed providing an overview of presence and utility of paper in today’s economy. Also, an introduction to modern papermaking processes and its key unit operations is covered. The fiber, chemistry, and process interactions are briefly studied. Wood and cellulose fiber structures and chemistry basics are taken further. Lastly, sustainable forestry principles are discussed as society balances today’s resource utilization while protecting the environment and future generations.

International audience; Wheat gluten coated papers containing carvacrol (15wt%) as anti-microbial agent and montmorillonite (0-7wt%) as filler were investigated as anti-microbial controlled delivery systems. The carvacrol losses were followed during the coating process and storage time at 30 infinity C under controlled RH from 40 to 100% RH. Increasing MMT content limited carvacrol losses during the coating process. A mathematical model based on Fick's second law was used to determine the apparent diffusivities of carvacrol from experimental data of kinetic release at 30 infinity C and controlled RH. Diffusivity values varied from 0.143 x 10(-14) m(2)/s (0wt% MMT, 40% RH) to 6.010 x 10(-14) m(2)/s (5wt% MMT, 100%RH) depending on both MMT% and RH. The carvacrol diffusivities increased with increasing RH, and the presence of a high amount of MMT(>= 5wt%) accentuated the RH-induced effect. Specific aggregated structure was evidenced by SEM and TEM in the presence of carvacrol and 5wt% MMT creating a preferential pathway for carvacrol diffusion. The anti-microbial efficiency of the MMT-WG-coated papers toward Escherichia Coil was assessed and showed that the antimicrobial effect was related to the carvacrol diffusivity. The diffusivity coefficients were utilized to optimize the packaging characteristics required to develop an efficient anti-microbial system and were finally validated against Botrytis cinerea.

Paper formation (the level of homogeneity in the distribution of fibers on the surface of paper) is a key quality parameter for paper products, being currently monitored off-line, at low sampling rates relatively to the high production speeds achieved with modern paper machines. In this paper, we address the problem of conducting such monitoring activity on-line, in situ, using wavelet texture analysis (WTA) on raw images acquired with a especially design sensor. Our analysis shows that either a reduced set of features derived from WTA (suggested by an ANOVA analysis), or a low dimensional sub-space (with two dimensions, obtained using PCA or PLS-DA), enable an adequate separation of the several paper formation quality grades, meaning that we can indeed follow, on-line, the quality status of paper formation. Furthermore, we will also show how statistical process control (SPC) can be properly conducted using WTA features, in a simple and robust way.