DOCSLIB.ORG

Surface Application of Paper Chemicals

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Surface Application of Paper Chemicals Surface Application of Paper Chemicals VISIT OUR FINE CHEMISTRY SITE ON THE WEB http://www.finechemistry.com e-mail orders: [email protected] Surface Application of Paper Chemicals Edited by JAMES BRANDER Head of Exploratory Research Arjo-Wiggins Limited Beaconsfield Buckinghamshire, UK and IAN THORN European Business Development Manager Eka Chemicals Weston-super-Mare Somerset, UK BLACKIE ACADEMIC & PROFESSIONAL An Imprint of Chapman & Hall London· Weinheim . New York· Tokyo· Melbourne· Madras Published by Blackie Academic and Professional, an imprint of Chapman & Hall, 2-6 Boundary Row, London SEt 8HN Chapman & Hall, 2--6 Boundary Row, London SE1 8HN, UK Chapman & Hall GmbH, Pappelallee 3, 69469 Weinheim, Germany Chapman & Hall USA, 115 Fifth Avenue, New York NY 10003, USA Chapman & Hall Japan, ITP-Japan, Kyowa Building, 3F, 2-2-1 Hirakawacho, Chiyoda-ku, Tokyo 102, Japan DA Book (Aust.) Pty Ltd, 648 Whitehorse Road, Mitcham 3132, Victoria, Australia Chapman & Hall India, R. Seshadri, 32 Second Main Road, CIT East, Madras 600 035, India First edition 1997 © 1997 Chapman & Hall Softcover reprint of the hardcover 1st edition 1997 Typeset in 1OI12pt Times by Cambrian Typesetters, Frimley, Surrey ISBN-13: 978-94-010-7151-2 e-ISBN-13: 978-94-009-1457-5 DOl: 10.1007/978-94-009-1457-5 Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the UK Copyright Designs and Patents Act, 1988, this publication may not be reproduced, stored, or transmitted, in any form or by any means, without the prior permission in writing of the publishers, or in the case of reprographic reproduction only in accordance with the terms of the licences issued by the Copyright Licensing Agency in the UK, or in accordance with the terms of licences issued by the appropriate Reproduction Rights Organization outside the UK. Enquiries concerning reproduction outside the terms stated here should be sent to the publishers at the London address printed on this page. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made. A catalogue record for this book is available from the British Library Library of Congress Catalog Card Number: 97-73236 ~ Printed on permanent acid-free text paper, manufactured in accordance with ANSIINISO Z39.48-1992 (Permanence of Paper). For our families Contents List of contributors xv Preface xvii Introduction 1 J. BRANDER and I. THORN Background 1 Technology of on-machine application 2 Chemicals for surface application 4 Paper products and surface treatment 6 IOn-machine surface treatment of paper and board with the blade coater 9 K. STRANGER 1.1 The origins of on-machine surface treatment 9 1.2 The blade-coating system today 9 1.3 Advantages and disadvantages of on-machine surface treatment 12 1.4 Paper and board grades utilizing on-machine surface treatment 13 1.5 Designing the surface treatment line 14 1.5.1 Webrun 14 1.5.2 Web-threading 15 1.6 Examples 15 1.6.1 Folding boxboard 16 1.6.2 Graphic board 16 1.6.3 Low-coat-weight papers 17 1.6.4 On-machine coated wood-free papers 18 1.6.5 Speciality papers 18 1.6.6 Conclusions 20 2 On-machine surface treatment of paper and board with the film press 21 R. RANTANEN 2.1 Introduction 21 2.1.1 Review of surface sizing equipment up to the 1980s 21 2.1.2 Metered size press technology 22 2.2 Quality and runnability aspects of different surface sizing processes 23 2.2.1 Two-roll size press 23 2.2.2 Gate-roll size press/coater 23 2.2.3 Blade surface sizing 24 2.3 New generation film presses 24 2.4 Coat-weight development and metering-element-related phenomena 25 viii CONTENTS 2.4.1 Grooved-rod metering 25 2.4.2 Smooth-rod metering 28 2.4.3 Large-diameter grooved-rod metering 30 2.4.4 Blade metering 31 2.5 Film transfer at film-press nip 31 2.5.1 Surface sizing 31 2.5.2 Coating 33 2.6 Precalendering 39 2.7 Control of paper quality 39 2.8 Nip mechanics and roll covers 40 2.9 Quality differences between film-press and blade coated sheets 42 2.10 The SymSizer film press 42 2.10.1 Process designs 42 2.10.2 Applications and production experiences 44 References 46 3 Synthetic latex binders for paper manufacture 48 G. BACQUET and I.-c. ISOARD 3.1 Introduction 48 3.2 From molecule to particle: latex synthesis 49 3.2.1 Radical emulsion polymerization 49 3.2.2 The monomers 51 3.2.3 Finishing and final characteristics 52 3.3 From particles to dispersion: latex stability 52 3.3.1 The importance of controlling stability 52 3.3.2 Stability control 54 3.4 The viscosity of latices and coating colors: the novel contribution of the particle state 55 3.4.1 Novelty of emulsion polymerlatices 55 3.4.2 The impact of the particle state and the chemistry of the latex on its viscosity 56 3.5 From particle to film: latex coalescence 58 3.5.1 Howtoobtainahomogeneousfilm 58 3.5.2 Wetting latex particles on pigments 60 3.5.3 Preventing film formation 61 3.6 From latex to coated paper: the role of polymers in a paper coating 62 3.6.1 Binding power 62 3.6.2 The latex polymer: an elastic material 63 3.6.3 Polymer chemistry as a modifier of paper surface energy 65 3.6.4 Porosity and ink setting in coated papers 66 3.7 Conclusions 67 References 68 4 Starches 69 N.-O. BERGH 4.1 Introduction 69 4.2 Principles of starch technology 69 4.2.1 Chemical principles 69 4.2.2 Physical properties of starch 72 4.3 Starch modification 76 4.3.1 Physical modification 76 4.3.2 Chemical modification 76 4.4 Surface application methods 82 CONTENTS IX 4.4.1 Size press 82 4.4.2 Apron size press 84 4.4.3 Foam-coat size press 84 4.4.4 Gate-roll coater 84 4.4.5 Metered size press 85 4.4.6 TWIN-HSM 86 4.4.7 Liquid application system 88 4.5 Starch properties required for size-press application 89 4.5.1 Influence of viscosity 90 4.5.2 Influence of solids content 93 4.5.3 Penetration 94 4.5.4 Influence of papermachine parameters 96 4.6 Starch properties required for metered size-press application 96 4.7 Starch properties required for blade application and as a coating colour binder 99 4.7.1 Blade application of starch solutions 99 4.7.2 Starch as a coating binder 102 4.8 Starch properties required when applied by liquid application system 105 4.9 Size-press starch application to waste-based packaging paper 105 4.9.1 One-sided size-press operation 106 5 Rheology modifiers and pigment dispersants 109 LB. CLARKE 5.1 Introduction 109 5.2 General principles of viscosity and rheology 109 5.3 Flow types encountered in paper surface treatment 111 5.3.1 Newtonianflow 111 5.3.2 Pseudoplasticflow 112 5.3.3 Dilatantflow 112 5.3.4 Thixotropicflow 113 5.3.5 Plastic flow 113 5.4 Variation of shear stress during surface application 114 5.5 Waterretention 115 5.6 Types of rheology modifier 116 5.6.1 Natural products 116 5.6.2 Synthetic polymers 117 5.6.3 Hydrophobic modification of synthetic polymers 119 5.7 Pigment dispersants 120 5.7.1 What is dispersion? 120 5.7.2 Electrostatic repulsion theory 122 5.7.3 Chemical types used as dispersants 122 5.7.4 Molecular weight effects 124 5.8 Interactions 126 5.8.1 Effect of pigment particle size distribution 127 5.8.2 Effect of multivalent cations 127 5.8.3 Effect oflatex formulation 127 References 128 6 Pigments for on-line surface treatment 129 I. ATIRUP and S. HANSEN 6.1 Introduction 129 6.2 The pigments 130 6.3 Application 132 6.3.1 Pigment choice 133 x CONTENTS 6.4 General paper improvement 133 6.4.1 De-inked-pulp-based paper 135 6.4.2 Porosity 135 6.5 Conclusions 137 References 137 7 Surface sizing 138 J. ANDERSON 7.1 Definition and overview 138 7.2 Chemicals applied at the surface 139 7.2.1 Types of chemicals 139 7.2.2 Wet-end sizes applied at the surface 140 7.2.3 Synthetic polymeric surface sizes 141 7.2.4 Miscellaneous specialities 142 7.3 Function of the products 143 7.3.1 Solution polymers 143 7.3.2 Acrylic emulsion polymers 144 7.3.3 Polyurethane microdispersions 144 7.4 End-use properties 145 7.4.1 Typical end-use properties 145 7.4.2 Plain fine paper 146 7.4.3 Coated paper and specialities 150 7.4.4 Recycled grades 150 7.5 Interactions and possible problems 151 7.5.1 Chemical compatibility at the size press 151 7.5.2 Foam 152 7.5.3 Contamination in closed systems 152 7.5.4 Size-press pick-up 153 7.5.5 Fixation and distribution of the size 153 7.5.6 Influence of post-treatment 153 7.5.7 Balancedsizing 154 References 155 8 Surface brightening of paper 156 H. WEAVER 8.1 Introduction 156 8.2 Spectra of different iIIuminants 156 8.3 The quantification of the effectiveness of fluorescent brightening agents 158 8.3.1 Quantum efficiency 158 8.3.2 Shade build curves 158 8.4 The chemical nature of fluorescent brightening agents 158 8.4.1 Disulpho brighteners 160 8.4.2 Tetrasulpho brighteners 161 8.4.3 Hexasulpho brighteners 162 8.4.4 Buffered brighteners 162 8.4.5 Tetrasulpho/hexasulpho mixtures 163 8.4.6 Other brightener types 163 8.5 Application of fluorescent brightening agents to paper 163 8.5.1 Surface application 164 8.5.2 Film-press versus size-press application 165 8.5.3 Brightener addition levels 165 8.6 Impairment of fluorescent brightening agents: greening and quenching 166 CONTENTS Xl 8.6.1 Concentration of fluorescent brightening agents 167 8.6.2 Acidity 167 8.6.3 Starch temperature 167 8.6.4 Cationicity 167 8.6.5 Other interfering substances 168 8.7 Lightfastness 169 8.7.1 Lightfastness of brighteners in solution 169 8.7.2 Lightfastness of brightened paper 169 8.8 Recycling 170 8.8.1 Charge considerations 170 8.8.2 Residual fluorescence 170 8.9 Monitoring and control of surface brightened paper 171 8.9.1 Instrument specification 171 8.9.2 Appropriate illumination 171 8.9.3 Stability 172 8.9.4 Geometry 172 8.9.5 Calibration 172 8.9.6 Cleanliness 172 8.9.7 Measurement 172 8.9.8 Control 173 8.10 Toxicology and ecotoxicity of fluorescent brightening agents 173 8.11 Summary of the effects and influences on surface addition of fluorescent brightening agents to paper 173 Acknowledgements 174 References 174 9 On-machine surface coloration 175 A.S.
Load more

Recommended publications
  • Annual Report Norske Skog
    09 ANNUAL REPORT NORSKE SKOG BOD report Sustainability 22 and accounts 96 report KEY FINANCIAL FIGURES DEFINITIONS 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 Income statement (NOK million) Operating revenue 20 362 26 468 27 118 28 812 25 726 25 302 24 068 23 471 30 354 26 635 Gross operating earnings 1 2 185 2 723 3 932 4 704 3 957 4 353 4 686 5 198 8 419 6 599 Operating earnings (1 325) (1 407) 677 (2 527) 630 757 1 536 1 306 5 096 4 211 Earnings before financial expenses 2 (1 209) (1 242) 785 (2 275) (51) 868 1 383 1 833 5 581 4 575 Profit/loss before income taxes (1 019) (2 779) 235 (3 480) (1 004) 210 770 806 3 894 3 021 Net profit/loss for the year (1 400) (2 765) (683) (3 017) (848) 629 406 1 168 2 660 2 184 Balance sheet (NOK million) Non-current assets 23 546 26 980 29 307 37 577 43 740 36 861 39 219 38 197 45 417 43 717 Current assets 9 609 18 211 13 953 7 653 8 293 7 238 7 119 6 769 10 855 17 510 Total assets 33 155 45 191 43 260 45 230 52 033 44 099 46 338 44 966 56 272 61 227 Total equity 12 015 13 632 15 957 18 550 22 679 18 894 19 416 17 921 19 526 22 351 Non-current liabilities 17 316 23 277 21 533 18 802 21 700 20 052 21 402 18 814 30 858 31 906 Current liabilities 3 824 8 282 5 770 7 878 7 654 5 153 5 520 6 210 5 888 6 970 Total equity and liabilities 33 155 45 191 43 260 45 230 52 033 44 099 46 338 42 945 56 272 61 227 Net interest-bearing debt 9 595 14 047 16 408 17 320 19 063 16 871 17 759 18 204 22 820 20 535 Profitability Gross operating margin % 3 10.73 10.30 14.50 16.30 15.40 17.20 19.50 22.10 27.70 24.80
    [Show full text]
  • 4.3 Optical Properties
    Summary Mechanical pulping is a process for production of wood pulp in papermaking. Thermomechanical Pulp (TMP) and Groundwood (GW) are historically the two production methods used for mechanical pulping. Because of high electrical prices and increasing requirements in pulp quality it is of interest to improve the mechanical pulping process. The Advanced Thermomechanical Pulp (ATMP) process is a development of the TMP process developed to reduce the electrical energy consumption in production of mechanical pulp. ATMP also has better strength properties and optical properties compared to TMP. Andritz, Paper and Fibre Research Institute (PFI) and Norske Skog together have developed this production method throughout several pilot plant trials with excellent results. Mechanical pre-treatment of wood chips with a screw press and chemical addition in a high intensity primary refining stage are the features of the ATMP process. This process has recently been described (Hill et al. 2009, Hill et al. 2010, Gorski et al. 2011 and Johansson et al. 2011). Improvements in the electrical energy efficiency in refining of up to 0,65 MWh/odt or 34 % as well as higher brightness and lower shive contents compared to reference TMP pulp were shown for spruce raw material (Gorski et al. 2011) To further understand what happens with the pulp in ATMP process compared to the TMP process different investigations were carried out. Methylene blue sorption were evaluated and used to measure the total amount of anionic groups on both ATMP and TMP produced pulps. ATMP produced pulps achieved a higher number of acidic groups compared to pulps without addition of chemicals for not only the whole pulp but also for three different fractions of each pulp.
    [Show full text]
  • Effects of Matte Coating on the Paper Surface and Print Density
    DOI 10.1515/secm-2012-0070 Sci Eng Compos Mater 2013; 20(2): 141–145 Cem Aydemir * , Zafer Ö zomay , Arif Karademir and Emine Arman Kand ı rmaz Effects of matte coating on the paper surface and print density Abstract: In this work, standard laboratory printing appli- papers. Fiber properties such as coarseness, beating, filler cations with IGT (ISO 12647-2) were applied on uncoated loading, pressing, calendering and coating are some of and matte-coated papers using offset inks (DIN ISO 2846-1). the main factors that mostly affect the surface roughness Surface roughnesses of uncoated and coated sheets were and porosity of paper products. The diameters of pores recorded to be 195 and 13 ml/min, respectively. Air perma- and uniform distribution in the paper structure are also nence values of uncoated and coated papers were found important for ink absorption [1, 2] . to be 5.6 and 0.103 μ m/Pa · s, respectively. Changes in A liquid droplet touching a paper surface tends to both the print densities were recorded up to 48 h. Print den- penetrate into the paper structure and spread over the sity changes for uncoated and matte-coated papers were surface. The extent of penetration or spreading depends surprisingly found to be in similar paths (8 % in the first on both the properties of the paper and liquids (ink) and 4 h), although significant differences between surface environmental conditions like temperature, humidity and roughnesses were recorded. Furthermore, paper samples pressure. Inks can be classified into three main groups showed similar behaviors for the percent volume changes, according to the carrier medium as solvent-based, oil-based where drop volume disappeared within 6 min.
    [Show full text]
  • 7/1 Environmental Exposure Assessment ENV/JM/EEA(2004)
    For Official Use ENV/JM/EEA(2004)7/1 Organisation de Coopération et de Développement Economiques Organisation for Economic Co-operation and Development 17-Aug-2004 ___________________________________________________________________________________________ _____________ English - Or. English ENVIRONMENT DIRECTORATE JOINT MEETING OF THE CHEMICALS COMMITTEE AND For Official Use ENV/JM/EEA(2004)7/1 THE WORKING PARTY ON CHEMICALS, PESTICIDES AND BIOTECHNOLOGY Environmental Exposure Assessment DRAFT EMISSION SCENARIO ON PULP AND PAPER INDUSTRY KRAFT PULP MILLS Meeting of the Task Force on Envionmental Exposure Assessment, to be held in Vienna, Austria on 13-15 September 2004 Mr. Eisaku Toda Tel: +33 1 45 24 79 07, Fax: +33 1 45 24 16 73, E-mail: [email protected] English - Or. English JT00168124 Document complet disponible sur OLIS dans son format d'origine Complete document available on OLIS in its original format ENV/JM/EEA(2004)7/1 This document includes a draft emission scenario document (ESD) on pulp and paper industry kraft pulp mills, submitted by Canada. Action required: The Task Force is invited to review this document, and consider the next steps for the finalisation of the document. 2 ENV/JM/EEA(2004)7/1 Emission Scenario Document for Kraft Pulp Mills Prepared for Environment Canada Environmental Protection Service New Substances Branch Place Vincent Massey, 351 St. Joseph Blvd., 14th Floor GATINEAU, QUEBEC, CANADA K1A 0H3 Contact: Mr. Jonathan Tigner Tel: (819) 997-5804 Fax: (819) 953-7155 E-MAIL: [email protected] Prepared by Crechem Technologies Inc. 1438 Bradshaw Crescent Ottawa, Ontario, Canada K1B 5G2 www.crechem.com Contact: Jesse Shen Tel: (613) 744-6001 Fax: (613) 744-0573 E-mail: [email protected] In association with JANCO 4 De Caria Blvd.
    [Show full text]
  • 2011 Vendor Application Commodity List Expanded.Xlsx
    City of Dayton Commodity Code List Select the Entire Sheet to UNHIDE the Detail Rows Section COMMODITY_ID COMMODITY_NAME 005 00500 ABRASIVES 00514 Abrasives, Coated: Cloth, Fiber, Sandpaper, etc. 00521 Abrasives, Sandblasting, Metal 00528 Abrasives, Sandblasting (Other than Metal) 00542 Abrasives, Solid: Wheels, Stones, etc. 00556 Abrasives, Tumbling (Wheel) 00563 Grinding and Polishing Compounds: Carborundum, Dia 00570 Pumice Stone 00584 Steel Wool 00599 Misc. Abrasives 010 01000 ACOUSTICAL TILE, INSULATING MATERIALS, AND SUPPLIE 01005 Acoustical Tile, All Types 01008 Acoustical Tile Accessories: Channels, Grids, Moun 01009 Acoustical Tile Insulation 01011 Adhesives and Cements, Acoustical Tile 01014 Adhesives and Cements, Insulation 01017 Aluminum Foil etc. 01030 Bands, Clips, and Wires (For Pipe Insulation) 01038 Clips, Pins, etc. (For Duct Insulation) 01041 Cork: Blocks, Boards, Sheets, etc. 01045 Exterior Insulation and Finish Systems 01053 Fiberglass: Batts, Blankets and Rolls 01056 Foam Glass: Blocks, Sheets, etc. 01057 Foam‐in‐Place Insulation: Phenolic, Urethane, etc. 01059 Foam Plastics: Blocks, Boards, Sheets, etc. 01063 Insulation, Blown Type 01065 Jacketing (For Insulation): Canvas, Osnaburg, etc. 01070 Magnesia: Blocks, Sheets, etc. 01072 Mineral Wool: Blankets, Blocks, Boards 01075 Paints, Primers, Sealers, etc. (For Insulation) 01076 Paper Type Insulation Material (Cellulose, etc.) 01078 Pipe and Tubing Insulation, All Types 01081 Preformed Insulation, All Types (For Ells, Tees, V 01084 Rubber Insulation 01099 Misc. Acc.
    [Show full text]
  • Paper and Surface Chemistry – Part 1- Fiber Surface and Wet End Chemistry
    Paper and Surface Chemistry – Part 1- Fiber Surface and Wet End Chemistry Pedro Fardim Instituto de Química, Universidade Estadual de Campinas, SP, Brazil Present Address: Process Chemistry Group, Åbo Akademi University, Turku/Åbo, Finland Abstract Paper manufacturing and converting involves a multitude of surface chemical interactions. Beating, stock preparation, coating and converting processes are steps where surface phenomena play an important role for product consolidation and performance. Interactions between fibers and colloidal particles, polymers, minerals and, dyes are fundamental in papermaking and most of them are complex and not very well understood. Thus, many paper formulations are designed according to an empirical trial-and-error approach. This work is a critical literature review of some of the interactions present in papermaking, coating, and printing. In the first part, the current models for fiber surfaces and their interactions in the wet end are discussed. Limitations concerning the fiber surface definition and the available models based on direct observation, DLVO theory, and a combination of qualitative and quantitative approaches are highlighted. Complexity factors such as surface composition heterogeneity, contamination from manufacturing processes, and surface mobility are suggested to be considered. Surface interactions present in the wet end, with focus on reversible and irreversible flocculation as well as on the flocculation mechanisms concerning fibers, polymers and micro-particles are also discussed. The role of the fiber surface chemical composition on flocculation and flock size and the influence from the chemical medium in the paper machine is reviewed. Papermaking is suggested as being a fiber surface modification process once polymers and other chemicals are used to change the surface energy and chemical composition.
    [Show full text]
  • Migration Studies of Chloropropanols from Paperboard Packaging
    MIGRATION STUDIES OF CHLOROPROPANOLS FROM PAPERBOARD PACKAGING IN CONTACT WITH FOODSTUFFS by GREGORY V. PACE A Dissertation submitted to the Graduate School - New Brunswick Rutgers, The State University of New Jersey in partial fulfillment of the requirements for the degree of Doctor of Philosophy Graduate Program in Food Science written under the direction of Professor Thomas G. Hartman and approved by ________________________ ________________________ ________________________ ________________________ New Brunswick, New Jersey January 2011 ABSTRACT OF THE DISSERTATION Migration Studies of Chloropropanols from Paperboard Packaging in Contact with Foodstuffs By GREGORY V. PACE Dissertation Director: Professor Thomas G. Hartman The food processing of acid hydrolyzed vegetable protein (HVP) results in the chlorination of residual lipids to form chloropropanols. 3-chloro-1,2-propanediol (3-monochloropropane-1,2-diol; 3-MCPD), and 1,3-dichloro-2-propanol (1,3-DCP), are the most common chloropropanols found in HVP foods and also soy sauces. The manufacturing process of paperboard food packaging may also produce chloropropanols. 3-MCPD and 1,3-DCP can be found in paperboard when wet-strength resins made with epichlorohydrin are used. 1,3-DCP had been determined to be carcinogenic in rats and mice. 3-MCPD was a suspected carcinogen , and has recently been moving towards classification as a carcinogen. The European (EU) Commission and the US Food and Drug Administration (US FDA) have set maximum levels in food and food paperboard packaging for 3-MCPD ii and 1,3-DCP. In October 2010, 3-MCPD and 1,3-DCP were added to the California Proposition 65 list of compounds known to State to cause cancer.
    [Show full text]
  • Pulp & Paper Chemicals
    Freedonia Industry Study #1531 Study Publication Date: March 2002 Price: $3,800 Pulp & Paper Chemicals Pages: 268 Pulp & Paper Chemicals, a new study from The Freedonia Group, provides you with an in-depth analysis of major trends in the industry and the outlook for product seg- ments and major markets -- critical information to help you with strategic planning. This brochure gives you an indication of the scope, depth and value of Freedonia's new study, Pulp & Paper Chemi- cals. Ordering information is included on the back page of the brochure. Brochure Table of Contents Study Highlights ............................................................................... 2 Table of Contents and List of Tables and Charts ............................. 4 Sample Pages and Sample Tables from: Market Environment .................................................... 6 Products....................................................................... 7 Demand by End User .................................................. 8 Industry Structure ........................................................ 9 Company Profiles ...................................................... 10 List of Companies Profiled ........................................ 11 Forecasting Methodology ............................................................... 12 About the Company ....................................................................... 13 Advantages of Freedonia Reports ................................................... 13 About Our Customers ...................................................................
    [Show full text]
  • The Fundamentals of Papermaking Materials
    Preferred citation: A. Swerin and L. Ödberg. Some aspects of retention aids. In The Fundametals of Papermaking Materials, Trans. of the XIth Fund. Res. Symp. Cambridge, 1997, (C.F. Baker, ed.), pp 265–350, FRC, Manchester, 2018. DOI: 10.15376/frc.1997.1.265. SOME ASPECTS OF RETENTION AIDS Agne Swerin and Lars Ödberg STFI, Swedish Pulp and Paper Research Institute Box 5604, S-114 86 Stockholm, Sweden ABSTRACT Fundamental aspects on polymer adsorption and flocculation phenomena are reviewed . Special emphasis is placed on recent developments . Examples are the mode of action of microparticle retention aid systems and of retention systems based on polyethylene oxide/phenolic resin. Fibre flocculation and the strength of fibrous networks are affected by retention aids and this is discussed in, connection with investigations on retention and formation in the laboratory and on pilot-scale paper machines . 266 INTRODUCTION This review article deals primarily with retention aids. Other papers presented at this symposium are devoted to other paper chemicals such as sizing agents and strength aids. Some of the discussion in this paper, e.g, on the adsorption of polyelectrolytes, is of course of relevance for some of these other areas as well. There are already extensive reviews available concerning retention aids and retention mechanisms (1, 2) and this review is therefore concentrated on more recent developments especially those not covered in the earlier reviews. We do not, however, claim to have covered all developments . There is, of course, some emphasis on the work done at STFI, primarily since this work is very familiar to us.
    [Show full text]
  • Cellulose-Based Electrical Insulation Materials Dielectric and Mechanical Properties REBECCA HOLLERTZ
    Cellulose-based electrical insulation materials Dielectric and mechanical properties REBECCA HOLLERTZ Doctoral thesis KTH Royal Institute of Technology School of Chemical Science and Engineering Department of Fibre and Polymer Technology ISBN 978-91-7729-327-9 TRITA – CHE-report 2017:21 ISSN 1654-1081 Tryck: US-AB, Stockholm, 2017 The following papers are reprinted with permission from: Paper I: Springer Papers II, III, VII and VIII: IEEE Transactions on Dielectric and Electrical Insulation AKADEMISK AVHANDLING Som med tillstånd av Kungliga Tekniska högskolan i Stockholm framläggs till offentlig granskning för avläggande av teknologie doktorsexamen fredagen den 12 maj 2017, kl. 10.00 i F3, Lindstedtsvägen 26, KTH, Stockholm. Avhandlingen försvaras på engelska. Fakultetsopponent: Professor Markus Biesalski, TU Darmstadt, Tyskland Copyright© Rebecca Hollertz, 2017 ABSTRACT The reliability of the generation and distribution of electricity is highly dependent on electrical insulation and is essential for the prosperity of our society and a ubiquitous part of our everyday life. The present study shows how some important material properties affect the electrical properties of cellulose-based electrical insulation systems which are used together with mineral oil in high-voltage transformers. Among other things, the effects of paper density and of the lignin content of the fibres on the dielectric response and charge transport of the papers have been studied. The underlying mechanisms of the inception and propagation of streamers, responsible for the most costly failures in transformers, at the oil-solid interface have been investigated and the important role of paper morphology on streamer propagation has been demonstrated. With papers, in contrast to films of synthetic polymers and microfibrillated cellulose, the branching of streamers increased and the length of slow negative streamers decreased.
    [Show full text]
  • The Influence of Process Conditions During Pulp Storage on The
    MECHANICAL PULPING Nordic Pulp & Paper Research Journal Vol 29 no (2) 2014 The influence of process waters on optical properties during storage of hydrogen-peroxide bleached Norway spruce mechanical pulp Sofia Enberg, Mats Rundlöf, Magnus Paulsson, Patrik Axelsson, Øyvind Eriksen and Per Engstrand KEYWORDS: Chemical characterisation, Colour, high brightness in a cost-efficient and environmentally- Mechanical pulp, Metal ions, Optical properties, Process friendly way. One drawback of mechanical pulp and conditions, Process waters, Pulp storage, Spectral data mechanical pulp based paper is discolouration due to ultraviolet radiation and heat (see e.g. Forsskåhl 2000; SUMMARY: To evaluate the causes behind the Paulsson, Parkås 2012). Mill experience shows that the formation of colour in mill systems, the effect of different brightness of bleached mechanical pulp is often reduced process waters on the optical properties of hydrogen- along the process line from the bleach tower to the paper peroxide bleached Norway spruce mechanical pulp machine (Johnsen et al. 2010; Narvestad et al. 2011). during storage was studied. The influence of process This is a well-known and costly phenomenon (Narvestad water type, temperature, time, pulp consistency and pH et al. 2013a) and there may be several reasons for the was evaluated over the visible range of wavelengths. The discolouration, which most probably varies within one darkening was more pronounced when pulp was stored in mill from time to time and from one mill to the next. process waters compared to in distilled water. Increased The brightness of unbleached and dithionite and/or temperature and prolonged storage times increased the hydrogen peroxide bleached softwood mechanical pulps darkening as expected, whereas a higher storage has been reported to decrease during pulp storage consistency gave less darkening than a lower storage (Gellerstedt et al.
    [Show full text]
  • Pretreatments for Converting Wood Into Paper and Chemicals
    Chapter 25 Pretreatments for Converting Wood into Paper and Chemicals William R. Kenealy1, Carl J. Houtman1, Jose Laplaza1, Thomas W. Jeffries1, and Eric G. Horn2 1Forest Service, Forest Products Laboratory, U.S. Department of Agriculture, Madison, WI 53726 2Biopulping International Incorporated, 2912 Syene Road, Madison, WI 53713 Biorefining wood into paper and chemicals is not as easy as making a single traditional paper product. Paper is made from the cellulose-containing fractions of wood and processing may remove lignin and hemicellulose components. The yield and composition of the product depend upon the type of paper being produced. The paper process often alters the non­ cellulose fractions, making them less suitable for conversion to other valuable products. This chapter will review methods of obtaining hemicellulosic sugars and investigate the potential for obtaining sugars by a wood pretreatment before it is made into pulp. As an example of hemicellulose removal the results of a new pretreatment using diethyl oxalate are also described. Hemicellulose removal by this system provides other benefits to the pulping process. 392 © 2007 American Chemical Society 393 Biomass use is touted as a solution to the burgeoning petroleum importation of our nation and as a way to become more energy independent (1). When biomass is targeted for this purpose, carbohydrates are generally converted to products. Corn is used to make ethanol, and it is principally starch that is saccharified to glucose and fermented to ethanol. Sucrose from sugar cane is used to make ethanol in Brazil. Obtaining sugars from lignocellulose is much more difficult. Cellulose has very little solubility in water and a crystalline nature that must be overcome before it can be converted into glucose.
    [Show full text]