Item Number: 0202FIN10 ISBN: 952-5216-10-1 Contents include: Calendering Reeling and winding Roll wrapping and handling Sheet finishing Chapter 1 - Calendering 1 Introduction...14 2 Calendering types...15 2.1 Hard nip calender...15 2.1.1 Hard nip calendering process...16 2.1.2 Hard nip calender concepts...18 2.2 Soft calender...23 2.2.1 Soft calendering process...23 2.2.2 Soft calender concepts...24 2.3 Supercalender...29 2.4 Multi-nip calender...35 2.4.1 Janus calender...36 2.4.2 Prosoft calender...38 2.4.3 OptiLoad calender...38 2.5 Specialty calenders...40 2.5.1 Wet stack...40 2.5.2 Breaker stack...40 2.5.3 Friction calender...41 2.5.4 Brush finishing...41 2.5.5 Long nip calenders...42 2.5.6 Embossing calenders...42 3 Calendering variables...43 3.1 Plasticity of the paper...44 3.1.1 Glass transition temperature...44 3.1.2 Other transitions...46 3.2 Paper and thermo roll temperature...46 3.3 Moisture...47 3.4 Linear load...48 3.5 Number of nips...49 3.6 Speed...50 3.7 Soft roll cover...50 3.8 Furnish...51 3.9 Coating color formulation...52 3.10 Roll surface roughness...52 4 Calendering process application areas...53 4.1 Wood-containing paper grades...53 4.1.1 Newsprint...54 4.1.2 SC paper...56 4.1.3 Coated wood-containing paper grades...58 4.2 Woodfree paper grades...59 4.2.1 Woodfree uncoated papers...59 Page 1 of 7
4.2.2 Woodfree coated papers...61 4.3 Board and specialty papers...64 4.3.1 Coated board...64 4.3.2 Uncoated board...67 4.3.3 Specialty papers: Release paper...67 4.3.4 Tissue papers...68 5 Deflection compensated rolls in calenders...68 5.1 The evolution...68 5.2 Theory of deflection compensation...70 5.3 Swimming rolls...71 5.4 Zone-controlled rolls...72 5.4.1 Mechanical design...72 5.4.2 Hydrostatic loading element...72 5.4.3 Floating bearings...74 5.4.4 Control system...74 6 CD-profile control rolls...75 6.1 Mechanical design...75 6.2 Control system...75 6.3 Hydrostatic bearings...76 7 Heated rolls...77 7.1 Process and design requirements...77 7.2 Construction...78 7.2.1 Center bore rolls...78 7.2.2 Displacer rolls...78 7.2.3 Peripherally drilled rolls...78 7.2.4 Mono-pass rolls...79 7.2.5 Duo-pass rolls...79 7.2.6 Tri-pass rolls...79 7.2.7 Multi-pass rolls...79 7.2.8 Tokuden rolls...79 7.3 Heating mediums...80 7.4 Roll materials...80 8 Roll coverings/soft roll covers...80 8.1 Coating materials...81 8.2 Calender soft rolls...82 8.2.1 The development of soft rolls...82 8.2.2 Filled rolls today...84 8.2.3 Polymer rolls today...89 8.2.4 Filled rolls versus polymer rolls...94 8.3 Other rolls...96 9 Unwind and windup...97 9.1 Unwind...97 9.2 Windup...99 10 Process control and automation...101 10.1 Control systems...101 10.2 Requirements and methods for calender control...102 10.3 Machine controls...104 10.4 Measurement of surface properties...106 10.4.1 Caliper...106 10.4.2 Smoothness...106 10.4.3 Gloss...106 10.4.4 Moisture...106 10.4.5 Temperature...107 10.4.6 Roll hardness...107 10.5 Actuators for control of paper surface properties...107 Page 2 of 7
10.5.1 Induction heating...107 10.5.2 Air showers...108 10.5.3 Zone-controlled rolls...108 10.5.4 Zone-controlled steam showers...110 10.6 Automatic on-line caliper control...110 10.6.1 Caliper control structure for a hard nip calender...111 10.6.2 CD caliper control structure for a soft calender...112 10.7 Automatic on-line smoothness and gloss control...114 10.7.1 Caliper, smoothness, and gloss control structure for a supercalender...114 10.8 Optimizing controls...115 10.8.1 Automatic grade change...115 10.8.2 Coordinated speed change control...116 10.8.3 Machine speed optimization control...116 10.8.4 Start-up control...117 11 Calendering problems...117 11.1 Profile problems...117 11.2 Reeling problems...118 11.3 Poor quality development...118 11.4 Barring problems...119 12 Modeling of calendering process...119 12.1 Introduction...119 12.2 Processes and models...120 12.3 Mathematical and empirical modeling approaches...121 12.3.1 Mathematical modeling...121 12.3.2 Empirical modeling...121 12.4 Calender nip process...122 13 Review in calendering modeling studies...124 13.1 Considerations on calender nip mechanics...124 13.1.1 The Hertz model...124 13.1.2 Numerical models for calender nip...126 13.2 Modeling the paper web behavior in calendering...126 13.2.1 Compressibility of paper...127 13.2.2 Heat and mass transport...132 References...136 Chapter 2 - Reeling and Winding 1 Introduction...143 2 Reeling and winding in papermaking...144 2.1 Winding requirements...144 2.2 Effect of paper properties on winding...146 2.3 Effect of winding on paper properties...148 3 Reeling...149 3.1 Process...149 3.1.1 Reeling parameters...150 3.1.2 Stresses inside parent reel...153 3.1.3 Parent reel structure...155 3.1.4 Air entrapment at reel...157 3.1.5 Reeling defects...158 3.2 Types and design...159 3.2.1 Pope reel...160 3.2.2 Second generation reels...160 3.2.3 Reel parts...165 3.2.4 Reels with lay-on roll for sensitive grades...170 Page 3 of 7
3.2.5 Rereeler...171 3.3 Production efficiency...172 3.4 Reel handling...178 3.4.1 Crane-based reel handling...180 3.4.2 Reel handling on transfer rolls...181 3.4.3 Reel handling with rail cart...182 3.4.4 Reel storage and waste pulping...182 4 Winding...183 4.1 Problems and challenges by paper grade...184 4.1.1 Newsprint...184 4.1.2 Glossy grades...184 4.1.3 Uncoated woodfree...185 4.1.4 Coated woodfree...185 4.1.5 Containerboard...186 4.1.6 Cartonboard and graphical board...186 4.2 Future trends...186 4.2.1 Raw materials...186 4.2.2 Papermaking and winding...186 4.2.3 Roll size...187 4.3 Two-drum winders...187 4.3.1 Winder functions...188 4.3.2 Automated functions...191 4.3.3 Two-drum winding parameters...192 4.3.4 Two-drum winders with a soft nip cover drum...193 4.3.5 Two-drum winder with air relief...193 4.3.6 Belt-supported winding...195 4.3.7 Variable geometry winder...195 4.3.8 Winding challenges of two-drum winders...195 4.4 Multistation winders...197 4.4.1 Multistation winder types used today in paper production...198 4.4.2 Paper and roll size demands for winding techniques...206 4.5 Winder automation...208 4.5.1 Maximizing capacity...208 4.5.2 Optimizing roll quality...209 4.5.3 Controlling roll structure...210 4.5.4 Optimizing winder capacity...212 4.5.5 Operator interface...216 4.5.6 Diagnostics...217 4.5.7 Communication and information services...218 4.5.8 Control system equipment...218 5 Theoretical background...218 5.1 Winding theory...218 5.1.1 Practical winding tools...219 5.1.2 Winding models...221 5.2 Web spreading...227 5.2.1 Spreading the machine-wide, uncut web...227 5.2.2 Separating the cut webs in the two-drum winder...230 References...236 Chapter 3 - Roll wrapping and handling 1 Introduction...239 2 Roll handling...240 2.1 Winder area layouts...240 2.1.1 Two-drum winder discharge area...240 Page 4 of 7
2.1.2 Two winders side-by-side...242 2.1.3 Discharge area of multi-station winders...243 2.2 Layout considerations...244 2.3 Vertical transportation in different layouts...246 2.4 Roll sorting...247 2.5 Label orientation...248 2.6 Automated storages...249 2.6.1 Automatic storage and automatic retrieval systems (AS/AR)...249 2.6.2 Automatic vacuum crane storage...249 2.7 Roll upending...250 2.7.1 In-line and side-feed upenders...251 2.7.2 Lowering upender...251 2.8 Flat top conveyors for upended rolls...252 2.9 Roll on the bilge pickup with rotating clamps...252 2.10 Roll shipping...253 2.11 Automatic truck loading...253 3 Roll wrapping...254 3.1 Paper roll protection...254 3.1.1 Requirements for roll wrapping...254 3.1.2 Impact of the paper grade...255 3.2 Wrapping process...259 3.2.1 Overlap wrapping...263 3.3 Wrapping materials...263 3.3.1 Wrapper stock...264 3.3.2 Inner heads...265 3.3.3 Outer heads...265 3.3.4 Gluing and sealing the package...266 3.3.5 Labels...267 3.3.6 Stretch film...267 3.3.7 Recycling the wrapping material...267 3.4 Multi-station wrapping machines...268 3.4.1 Identification and centering...269 3.4.2 Indexing from station to station...269 3.4.3 Wrapper feed and crimping...269 3.4.4 Header press...270 3.4.5 Head delivery...270 3.4.6 Labeling and marking...271 3.5 Single-station wrapping machines...272 3.6 Stretch-wrapping machines...273 4 Process management...274 4.1 General...274 4.2 System structure...274 4.3 Winder and rewinder...275 4.4 Roll tracking...275 4.5 Intermediate (in-process) storage...275 4.6 Wrapping...276 4.7 Roll sorting...276 4.8 Warehouse...276 4.9 Shipping...277 4.10 Reports...277 4.11 Remote links...277 References...278 Chapter 4 - Sheet finishing Page 5 of 7
1 Introduction...281 1.1 Sheets and sheet finishing...281 1.2 The world's paper and board sheet production...284 2 Specifications of the sheets and their raw material...284 2.1 Sheet finished product...284 2.1.1 Customer-related requirements...285 2.1.2 Quality and housekeeping in the sheet finishing...285 2.2 Raw material for the sheet finishing...287 2.2.1 The effect of the winder operations...288 2.2.2 Paper or board properties...289 2.2.3 Handling and warehousing...289 2.2.4 Other factors...290 3 Sheet finishing process and machinery...290 3.1 Sheet cutting process...290 3.1.1 Unwinding...290 3.1.2 Roll change and splicing...292 3.1.3 Web tension control...293 3.1.4 Web curl compensation...293 3.1.5 Web position control...294 3.1.6 Slitting...295 3.1.7 Draw roll section...297 3.1.8 Cross cutting unit and reject gate...298 3.1.9 Overlapping...300 3.1.10 Sheet piling...301 3.1.11 Other processes...302 3.2 Typical features of sheet cutting machines and factors affecting the selection of those...302 3.2.1 Folio sheet cutting machines...302 3.2.2 Cut size machines...310 3.2.3 Guillotines...312 4 Packaging of the sheets...314 4.1 Packaging of the cut size sheets...314 4.1.1 Specifications of the cut size packaging...314 4.1.2 The cut size packaging lines...314 4.2 The ream wrapping and the carton packaging of the folio sheets...316 4.2.1 Specifications of the folio sheet packaging...316 4.2.2 Ream wrapping and carton packaging machinery...317 4.3 Palletizing...317 4.3.1 Requirements for sheet pallet packing...317 4.3.2 Pallet packaging equipment...320 5 Other processes in the sheet finishing...323 5.1 Co-processes to the sheet finishing...323 5.1.1 The incoming packaging materials...323 5.1.2 Re-piling and sorting...324 5.1.3 Guillotine cutting operations...324 5.1.4 Quality control and traceability of the products...325 5.2 Sheet finishing broke and waste handling...326 5.2.1 The creation of the sheet finishing broke...326 5.2.2 Handling of broke...327 5.2.3 Minimizing the amount of the broke...328 5.3 Roll storage and the transportation of rolls to the sheet finishing plant...329 5.4 The storage of the ready-made sheets...330 5.5 Conditions in a sheet finishing plant...331 5.6 The maintenance in the sheet finishing plant...332 6 The effectiveness and the efficiency of the sheet finishing...334 6.1 The capacity of the sheet finishing...334 Page 6 of 7
6.1.1 The definition of the sheet cutter efficiency...336 6.1.2 The construction of the sheet cutter...338 6.1.3 The operational factors...341 6.2 The effective sheet finishing production...343 6.2.1 Design capacity...343 6.2.2 Actual capacity...344 6.3 The principles and problems of the production planning...345 6.3.1 Folio sheet cutting...345 6.3.2 Cut size...345 6.4 The cost of the sheet finishing...345 References...348 Further reading...350 Abbreviations...353 Page 7 of 7