Retention of Fines and Fillers During Papermaking PDF Download

Author: Jerome M. Gess
Publisher: Tappi
ISBN: 9780898520668
Category : Fillers (Materials)
Languages : en
Pages : 0

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Author: P. Somasundaran
Publisher: CRC Press
ISBN: 9780849395741
Category : Science
Languages : en
Pages : 1084

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Author: Christian Rompf
Publisher: diplom.de
ISBN: 3836644460
Category : Technology & Engineering
Languages : en
Pages : 91

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Inhaltsangabe:Introduction: It is important to determine the distribution fillers in thickness direction of paper. However, the techniques that are available are limited in precision and accuracy. This thesis describes a new method for the determination of fillers in the z-direction of paper. The method is based on a splitting technique that offers a good reproducibility and provides good layer uniformity. The new method is used to estimate the effects of different factors of influences affecting the fillers distribution. During sheet forming a large amount of water is removed. This dewatering process creates an irregular distribution of fillers across the thickness of the paper. Therefore, the description of the distribution of fillers in the thickness direction is critical to optimize paper properties. The techniques currently available for this kind of characterization have limitations in terms of repeatability, resolution or precision. Another limitation to currently available techniques is the lack of a good sampling area. Considering the large effect of fillers on many paper properties, the ability to measure and thus control the filler distribution in the z-direction helps to control sheet structure, reduce two-sidedness and improve paper properties such as internal bond. Inhaltsverzeichnis:Table of Contents: Acknowledgements2 Abstract3 Index of contents4 1.Introduction6 1.1Paper structure7 1.1.1Three dimensional network8 1.1.2Formation11 1.2Fillers12 1.2.1Effects of filler loading on the properties of paper12 1.2.2The main fillers:14 1.3Retention and dewatering16 1.3.1First-pass retention and true retention17 1.3.2Agglomeration and flocculation20 1.3.3Retention fundamentals:23 1.3.4Filler distribution24 1.4Measuring filler content and distribution25 2.Materials and methods28 2.1.1Measuring filler distribution28 2.1.2The procedure of splitting33 2.1.3Acquisition of the images35 3.Results and Discussion37 3.1Settings of the scanner38 3.2Different backgrounds40 3.3Repeatability of the method42 3.4Influence of the position of filler addition43 3.5SC Paper with 42,8 % GCC53 3.6TMP - Paper 20% GCC57 3.7Fine paper with 20 % and 30 % of GCC63 3.8Different positions of adding GCC73 4.Summary83 5.Sources84 6.List of Figures86 Textprobe:Text Sample: Chapter 1.3.4, Filler distribution: The distribution of filler material in the paper depends on the forming process. Fillers can be entrapped mechanically into the web, [...]

Author: Cornel Hagiopol
Publisher: CRC Press
ISBN: 143985646X
Category : Science
Languages : en
Pages : 431

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Chemistry of Modern Papermaking presents a chemist's perspective on the papermaking process. With roughly 3% of the mass of a paper product invested in water-soluble chemicals, paper makers can adjust the speed and efficiency of the process, minimize and reuse surplus materials, and differentiate a paper product as required by specific customers. W

Author: Che On Au
Publisher: Springer Science & Business Media
ISBN: 9401707561
Category : Technology & Engineering
Languages : en
Pages : 215

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Commercial demands and increasing global competition have led to enormous mechanical evolution over recent years. Twin-wires, wide-nip presses, steam boxes and speed sizers have all played a part in improving both the productivity and quality of paper and board products. With the emphasis on mechanical and electrical engineering and the ever increasing pressures of quality measurement and control, little time has been available within a technical department for much reflection on the chemistry of the process. Thus there is a growing trend for the management of the wet-end to be delegated to the chemical supplier. The advances in scale of paper manufacture, environmental sensitivity and higher quality of end-product requirements have all had an impact on the chemistry of the wet-end. The increased production means, for example, that down time is more of an anathema now when capacity is critical. Similarly, with the greater rigours of quality management, anything which causes breaks or holes must be eradicated. Environmental pressures too are growing on the papermaking process. Even if consideration is restricted to only the closure of the white water circuit, it alone throws down a challenge to the potency of biocides, retention aids and other chemicals. These chemicals are detriment ally affected by an increasing concentration of water soluble pulp extractives and surfactants, adhesives and polysaccharides from broke and recycled paper.

Author: Christopher J. Biermann
Publisher: Elsevier
ISBN: 008053368X
Category : Technology & Engineering
Languages : en
Pages : 783

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In its Second Edition, Handbook of Pulping and Papermaking is a comprehensive reference for industry and academia. The book offers a concise yet thorough introduction to the process of papermaking from the production of wood chips to the final testing and use of the paper product. The author has updated the extensive bibliography, providing the reader with easy access to the pulp and paper literature. The book emphasizes principles and concepts behind papermaking, detailing both the physical and chemical processes. A comprehensive introduction to the physical and chemical processes in pulping and papermaking Contains an extensive annotated bibliography Includes 12 pages of color plates

Author: Ian Thorn
Publisher: Springer Science & Business Media
ISBN: 1402060386
Category : Science
Languages : en
Pages : 233

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"Applications of Wet-end Paper Chemistry" bridges the gap between the theory and practice of wet-end paper chemistry by explaining how particular chemicals are chosen and put to use in real situations. A number of international experts in the field present recent contributions on the optimum use of chemicals in papermaking. Major inroads have taken place since the first edition of this title was published in 1995. This new edition of "Applications of Wet-end Paper Chemistry" will reflect the changing type and use of chemicals used in papermaking in the 21st century. Chemists and chemical engineers across the paper and pulp making industry, as well as in research and academic institutes will find this book of enormous practical value.

Author: Monica Ek
Publisher: Walter de Gruyter
ISBN: 3110213443
Category : Science
Languages : en
Pages : 409

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This four volume set covers the entire spectrum of pulp and paper chemistry and technology from starting material to processes and products including market demands. This work is essential for all students of wood science and a useful reference for those working in the pulp and paper industry or on the chemistry of renewable resources. Volume 3 provides an overview of paper production and the ways in which the chemistry of starting materials and processes influence its quality and properties. The work treats fundamental properties of the fibre wall and the consolidation of fibres during pressing and drying, surface chemistry of fibres and their influence on the interaction between fibres/paper and other materials, mechanisms behind the adsorption of polyelectrolytes to fibres and fillers, acid and alkaline sizing of paper, basic fluid mechanical behavior of fibre suspensions, web forming, web pressing and web drying in a modern paper machine, calandering and coating of paper.

Author: Marguerite Rinaudo
Publisher: MDPI
ISBN: 3038978027
Category : Science
Languages : en
Pages : 414

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Functional advanced biopolymers have received far less attention than renewable biomass (cellulose, rubber, etc.) used for energy production. Among the most advanced biopolymers known is chitosan. The term chitosan refers to a family of polysaccharides obtained by partial de-N-acetylation from chitin, one of the most abundant renewable resources in the biosphere. Chitosan has been firmly established as having unique material properties as well as biological activities. Either in its native form or as a chemical derivative, chitosan is amenable to being processed—typically under mild conditions—into soft materials such as hydrogels, colloidal nanoparticles, or nanofibers. Given its multiple biological properties, including biodegradability, antimicrobial effects, gene transfectability, and metal adsorption—to name but a few—chitosan is regarded as a widely versatile building block in various sectors (e.g., agriculture, food, cosmetics, pharmacy) and for various applications (medical devices, metal adsorption, catalysis, etc.). This Special Issue presents an updated account addressing some of the major applications, including also chemical and enzymatic modifications of oligos and polymers. A better understanding of the properties that underpin the use of chitin and chitosan in different fields is key for boosting their more extensive industrial utilization, as well as to aid regulatory agencies in establishing specifications, guidelines, and standards for the different types of products and applications.

Author: J.C. Roberts
Publisher: Springer Science & Business Media
ISBN: 9401106053
Category : Technology & Engineering
Languages : en
Pages : 278

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Book Description
Although the title of this book is Paper Chemistry, it should be considered as a text about the chemistry of the formation of paper from aqueous suspensions of fibre and other additives, rather than as a book about the chemistry of the raw material itself. It is the subject of what papermakers call wet-end chemistry. There are many other excellent texts on the chemistry of cellulose and apart from one chapter on the accessibility of cellulose, the subject is not addressed here. Neither does the book deal with the chemistry of pulp preparation (from wood, from other plant sources or from recycled fibres), for there are also many excellent texts on this subject. The first edition of this book was a great success and soon became established as one of the Bibles of the industry. Its achievement then was to collect the considerable advances in understanding which had been made in the chemistry of papermaking in previous years, and provide, for the first time, a sound physico chemical basis of the subject. This new edition has been thoroughly updated with much new material added. The formation of paper is a continuous filtration process in which cellulosic fibres are formed into a network which is then pressed and dried. The important chemistry involved in this process is firstly the retention of col loidal material during filtration and secondly the modification of fibre and sheet properties so as to widen the scope for the use of paper and board products.