Papermaking, fibre flocculation, fine element, retention
These retention aids are efficient but not selective: they help attaching fine elements to fibres but also cause additional fibre flocculation, which is detrimental to optical and mechanical properties of the sheet. The objective of this study is to find strategies to minimise fibre flocculation, while ensuring an acceptable fine elements retention.
(PDF) Perspectives on Fibre Flocculation in Papermaking
The impact of retention on the level of fine elements in the headbox is estimated through a simple model of the short circulation. Flocculation measurements on a pilot scale flow loop show that
Pulp, fibre flocculation, fine elements retention
It is estimated, through a simple model of the short circulation, that such a level of fine elements can be observed in the headbox of a papermachine with a fine elements retention of 63 %. Fibre flocculation measurements on a pilot scale flow loop show that fine elements, consisting of a mixture of 1/3 fines and 2/3 filler, do not mechanically
Retention and Formation in Papermaking Sveacon
Retention and Formation in Papermaking Author: Boris Zhmud Keywords: retention,retention system,coagulant-flocculant system,fibre flocculation,fiber flocculation,web structure,wet-end chemistry,pressure profile in the nip,Fourdrinier wire,filter cake permeability,Sveacon Created Date: 2/3/2007 8:30:58 PM
THE DISPERSION SCIENCE OF PAPERMAKING
The mechanism by which alum promotes retention usually is explained in terms of a reduction in electrostatic repulsion forces between the solid surfaces in the aqueous suspension of fibers, mineral particles, and other papermaking additives. Early success at achieving yet stronger flocculation and higher retention was achieved by a combination
Flocculation, Retention and Drainage in Papermaking: A
Fibre and filler flocculation, filler retention and drainage, induced by several polymeric retention aids, were compared in laboratory experiments on mixtures of kraft fibres and two calcium
The Papermaking Bible A definative Guide : April 2017
A balance has to be made between the flocculation of stock and the drainage of the stock. This balance results in a need for fiber flocculation to be limited but the flocculation of fine particles and retention additives should be maximized. As the fibers and fillers flock together to form bonds the drainage on the wire decreases. The molecular
Flocculation and formation in papermaking jan 2018
2018-01-18· Flocculation and formation in papermaking jan 2018 1. Pele Oy Flocculation, Formation and Paper Properties Pekka Komulainen [email protected] January, 2018 2. Pele Oy Flocculation and formation Flocculation of fibers occur in the approach flow. Headbox tries to destroy flocs and disperse fibers. Fiber flocs from the headbox and on
Flocculation studies in papermaking final
flocculation studies in papermaking elisabete simÕes antunes university of coimbra f overview of the wet-end chemistry in papermaking 19 1.2. retention and drainage in papermaking 22 1.2.1 chemical aspects of retention 22 1.2.2 flocculation mechanisms 25 1.2.3 factors that influence retention mechanisms 30 1.2.4 drainage mechanisms 37 1.2.5 retention and drainage
RETENTION AID POLYMER INTERACTIONS WITH CELLULOSIC
RETENTION AID POLYMER INTERACTIONS WITH CELLULOSIC SURFACES AND SUSPENSIONS: A REVIEW Martin A. Hubbe,a* Hiroki Nanko, and Michelyn R. McNeal b Retention aids can be defined as very-high-mass, water-soluble polymers that are added to cellulosic fiber slurries before the formation of paper in order to improve the efficiency with which fine
Retention of Fines and Fillers During Papermaking, Item #0102B
S pecific topics include retention in a neutral alkaline papermaking system and pigments for retention, including titanium dioxide and talc . A project of the Papermaking Additives Committee of the Paper and Board Division, this new text is a revision of Retention of Fine Solids During Paper Manufacture, last publis hed in 1975.
How Polyacrylamide Works for Papermaking Industry
However, since retention has to be balanced with an adequate drainage of the wet web and a good formation of the paper sheet, fiber flocculation should be limited whereas flocculation of fine particles and retention additives should be maximized. In papermaking, cationic polyacrylamides are usually used as retention aids. The efficiency of
Fourdrinier Retention Mechanisms The Papermaking Bible
The ideal scenario would be to restrict fiber to fiber flocculation and encourage the smaller particles and additives to flock to the fibers. This would give the best retention and dewatering of the sheet. Bellow is a table that describes the elements of papermaking that will affect the retention on a fourdrinier machine, they can be catagorised into, Pulp conditions, Wire conditions and the
Hetero-flocculation of wood fibres and fines induced
Hetero-flocculation of wood fibres and fines induced by polymers and microparticles, Asselman, Tom., Engineering, Chemical., The retention of process colloids in the paper web is essential for papermaking process efficiency and product quality. Fines (fibre fragments) and fillers strongly affect the optical, surface and mechanical properties of paper.
Flocculation, retention and drainage in papermaking: a
2007-04-01· INTRODUCTION Wet-end aids are increasingly used in papermaking to fix fine particles onto fibres, to cause agglomeration of fines and fillers, allowing their capture in a forming sheet and thus to reduce the entrainment of fine solid particles by the water which is rapidly drained from the thickened pulp and the forming fibre web in the entry section of a paper machine.
Formation Uniformity (Troubleshooting Guide)
Formation uniformity (Flocs, Streaks) FLOCCY PAPER. Nonuniformity of paper within a length scale of 2-20 mm is most frequently associated with a tendency of fibers to form flocs.It is important to keep in mind that a certain degree of fiber flocculation can be expected, regardless of chemical conditions in a papermaking furnish.
Enzymatic nanocellulose in papermaking The key role
2019-11-15· In the present work, strategies to improve filler flocculation and the papermaking properties, by using enzymatic CMF, are provided. The CMF degree of polymerization was found to be directly related to precipitated calcium carbonate flocculation, leading to higher retentions in the fibre matrix. Besides, the paper dry and wet strengths were
Papermaking an overview ScienceDirect Topics
Flocculation in the Papermaking System. Flocculation in papermaking chemistry is analogous to coagulation except that a charged polymer is used to either decrease the repulsive forces or act with several particles at one time (bridging) to achieve aggregation. Consider the use of cationic polymers in a solution of wood fiber fines with negative
theses.fr Patrick Huber,Interdépendance de la
L'objectif de cette étude est d'estimer dans quelle mesure la rétention des éléments fins et la floculation des fibres (due aux agents de rétention) sont liées dans le processus de fabrication de la feuille, de façon à maximiser la rétention tout en limitant la floculation. Dans le but de caractériser l'état de floculation, deux manières de calculer l'encombrement dans des
Valuation of retention/formation relationships using a
mechanistic concept laid the foundation for the subsequent research on fibre flocculation. Mechanical flocculation gives rise to fibre networks (flocs), where the fibres are mechanically interlocked in the network if the fibre is in contact with at least three other fibres. Regarding fibre flocculation, the number of contacts per fibre is
REVIEW ARTICLE ncsu.edu/bioresources
Fiber flocculation appears to depend on phenomena occurring within two markedly different ranges of size. At a molecular scale, suspensions of cellulosic materials and fine particles are affected by short-range electrostatic, dispersion, and polymer bridging forces acting between surfaces. At a macroscopic scale, cellulosic fibers are sufficiently long, relative to their thickness, so that
Polyacrylamide Applications in Papermaking Industry
3. The polyacrylamide can be used as the dispersing agent. The dispersing agent is a common additive in the paper making industry to reduce the fiber flocculation which can improve the paper formation, thereby, it is also known as the “resistance” or the “suspension” of the flocculant. In both the handmade paper and the mechanical copy
Flocculation efficiency of chitosan for papermaking
Full Article. Flocculation Efficiency of Chitosan for Papermaking Applications. Raluca Nicu, a Elena Bobu, a, * Ruben Miranda, b and Angeles Blanco b There is a large interest in bio-polymers as environment-friendly alternatives to synthetic additives in papermaking.
polyacrylamide for papermaking
Polyacrylamide Applications in Papermaking Industry. 3. The polyacrylamide can be used as the dispersing agent. The dispersing agent is a common additive in the paper making industry to reduce the fiber flocculation which can improve the paper formation, thereby, it is also known as the “resistance” or the “suspension” of the flocculant.
Paper Manufacture and the Importance of Zeta Potential
2005-05-03· Please use one of the following formats to cite this article in your essay, paper or report: APA. Malvern Panalytical. (2019, September 03). Paper Manufacture and the Importance of Zeta Potential to the Paper Manufacturing Process.
Retention Aids / Coagulants / Fixing Agents| Paper
Retention Aids. Retention aids improve drainage and increase retention of fine particles. They function as both productivity aids and product improvement since they increase speed and increase fines retention. They improve the clarity of the waste water and greatly reduce the negative environmental impact of water reuse. Retention Aids RD Series
Cellulosic Fibers from Lignocellulosic Biomass
The obtained fibrous suspensions were characterized by measuring their dimension parameters (fiber length, fiber width, and fine elements), polymerization degree, and their retention water capacity. The effect of pulping process on yield and fiber characteristics in each pulp was studied. The surface morphologies of the produced papers were
Forming is the first step in the papermaking process. Its specific objective is to drain water from a dilute fiber suspension on a forming fabric, and to create a uniform fiber mat that is strong enough to be passed to the press section of the paper machine. Forming has a strong influence on a range of paper properties. It determines the
Influence of TEMPO-oxidised cellulose nanofibrils on the
Abstract. In this work, cellulose nanofibrils (CNF) were produced from a Eucalyptus globulus bleached kraft pulp by TEMPO-mediated oxidation and mechanical homogenisation, and their effects in papermaking, namely filler flocculation and retention, dry and wet-web strength and structural properties, were studied in detail. Cellulose nanofibrils possessing 0.6 mmol/g carboxyl groups and
Patrick Huber Paper-based materials development
Sylvie Ossard, Patrick Huber, Pascal Borel, Davy Soysouvanh, Thierry Delagoutte, Paper 19-2: New Automated Method For Macro-Contaminant Analysis: Industrial Applications, has been selected as the best paper and Wayne Carr award winner from the Recycling Forum last year in Jacksonville.
Flow properties of cellulose fiber suspensions DeepDyve
Retention aid systems are commonly used in the papermaking process to flocculate the fine matericals in cellulose fiber suspensions. The addition of polymeric flocculants such as cationic polyacrylamide (C-PAM) also increases the fiber flocculation and the shear strength of the fiber flocs. The break-up process of fiber flocs in highly turbulent flow is of great importance to produce paper
FLOCCULATION AND REDISPERSION OF CELLULOSIC
The net effect of flocculation determines how uniformly fibers can become formed into a sheet during the manufacture of paper. At a macroscopic level, the highly elongated shape of typical wood-derived fibers in agitated sus-pensions can give rise to frequent inter-fiber collisions and the formation of fiber flocs. At a submicroscopic scale
Vol8 Papermaking Part 1, Stock Preparation and Wet End
Papermaking Science and Technology a book series covering the latest technology and future trends Book 8 Second Edition Totally updated version Book editor Hannu Paulapuro, D. Sc. (Tech.), Professor, Department of Forest Products Technology, Paper Technology, Helsinki University of Technology Publisher Finnish Paper Engineers’ Association/Paperi ja Puu Oy Paperi ja Puu Oy Papermaking
Paper Papermaking, Paper Papermaking Suppliers
Alibaba offers 13,570 paper papermaking products. About 35% of these are paper machinery parts, 12% are paper chemicals, and 8% are petroleum additives. A wide variety of paper papermaking options are available to you, such as coating auxiliary agents, paper chemicals, and water treatment chemicals.
(PDF) Use of New Branched Cationic Polyacrylamides to
mers have a significant potential as retention aids in papermaking In this case, the drainage time is mainly affected by the larger due to the improvement of retention and drainage of pulp fiber floc size (overflocculation). suspensions. The effects of the polymer charge density and degree of Correlation with Floc Properties. Since the best
papermaking dispersing agent anionic polyacrylamide
Dispersing Agent Cationic Polyacrylamide Powder For Paper Making Chemicals MW>16 Million . Dispersing agent for paper making is a kind of composite high molecular weight polymer, whose appearance is white fine granule. It is water soluble and the solution has high viscosity. It will promote the dispersing of the fiber and the form of the paper
Improvement of the retention-formation relationship using
Improvement of the retention-formation relationship using three-component retention aid systems Anna Svedberg Doctoral Dissertation Stockholm 2012 Royal Institute of Technology Department of Fibre and Polymer Technology SE-100 44 Stockholm, Sweden . Typeset in Garamond. TRITA-CHE REPORT 2012:19 ISSN 1654-1081 ISBN 978-91-7501-314-5 Akademisk avhandling som med tillstånd av
Flocculation and formation in papermaking jan 2018
Flocculation and formation in papermaking jan 2018 1. Pele Oy Flocculation, Formation and Paper Properties Pekka Komulainen [email protected] January, 2018 2. Pele Oy Flocculation and formation Flocculation of fibers occur in the approach flow. Headbox tries to destroy flocs and disperse fibers. Fiber flocs from the headbox and on the wire fix to the sheet when water removes. This
Deflocculants: A Detailed Overview digitalfire
Deflocculants: A Detailed Overview Section: Clay Bodies, Subsection: General Description. A detailed look and what deflocculation is, what the most common types of deflocculants are (there are many) and how they compare in function. Article Text Deflocculation and Flocculation. The particles of an argillaceous material, when suspended in water, behave in two entirely different ways, since the
Retention Efficiency Problems (Troubleshooting Guide)
RETENTION EFFICIENCY TOO HIGH. Papermakers almost never complain that the first-pass retention on their paper machine is too high, but they do complain about poor formation uniformity. If the paper has a higher than necessary degree of fiber flocculation, then it may be a good idea to cut back on the retention aid dosage.