PAPER AND PAPERBOARD PACKAGING TECHNOLOGY

Transcription

1 PAPER AND PAPERBOARD PACKAGING TECHNOLOGY Edited by MARK J. KIRWAN Consultant in Packaging Technology London, UK Blackwell Publishing

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3 Paper and Paperboard Packaging Technology

4 Packaging Technology Series Series Editor: Geoff A. Giles, Global Pack Management, GlaxoSmithKline, London. A series which presents the current state of the art in chosen sectors of the packaging industry. Written at professional and reference level, it is directed at packaging technologists, those involved in the design and development of packaging, users of packaging and those who purchase packaging. The series will also be of interest to manufacturers of packaging machinery. Titles in the series: Design and Technology of Packaging Decoration for the Consumer Market Edited by G.A. Giles Materials and Development of Plastics Packaging for the Consumer Market Edited by G.A. Giles and D.R. Bain Technology of Plastics Packaging for the Consumer Market Edited by G.A. Giles and D.R. Bain Canmaking for Can Fillers T.A. Turner PET Packaging Technology Edited by D.W. Brooks and G.A. Giles Food Packaging Technology Edited by R. Coles, D. McDowell and M.J. Kirwan Paper and Paperboard Packaging Technology Edited by M.J. Kirwan Packaging Closures and Sealing Systems Edited by N. Theobald

5 2005 by Blackwell Publishing Ltd Editorial Offices: Blackwell Publishing Ltd, 9600 Garsington Road, Oxford OX4 2DQ, UK Tel: +44 (0) Blackwell Publishing Professional, 2121 State Avenue, Ames, Iowa , USA Tel: Blackwell Publishing Asia Pty Ltd, 550 Swanston Street, Carlton, Victoria 3053, Australia Tel: +61 (0) The right of the Author to be identified as the Author of this Work has been asserted in accordance with the Copyright, Designs and Patents Act All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher. First published 2005 by Blackwell Publishing Ltd Library of Congress Cataloging-in-Publication Data Paper and paperboard packaging technology / edited by Mark J. Kirwan. p. cm. Includes bibliographical references and index. ISBN-10: (hardback : alk. paper) ISBN-13: (hardback : alk. paper) 1. Paper containers. 2. Paperboard. 3. Packaging. I. Kirwan, Mark J. TS198 3.P3P dc ISBN-10: ISBN-13: A catalogue record for this title is available from the British Library Set in 10/12pt Times by Integra Software Services Pvt. Ltd, Pondicherry, India Printed and bound in India by Replika Press Pvt. Ltd, Kundli The publisher s policy is to use permanent paper from mills that operate a sustainable forestry policy, and which has been manufactured from pulp processed using acid-free and elementary chlorine-free practices. Furthermore, the publisher ensures that the text paper and cover board used have met acceptable environmental accreditation standards. For further information on Blackwell Publishing, visit our website:

6 Contents Contributors Preface Acknowledgements xviii xix xxi 1 Paper and paperboard raw materials, processing and properties 1 MARK J. KIRWAN 1.1 Introduction quantities, pack types and uses Choice of raw materials and manufacture of paper and paperboard Introduction to raw materials and processing Sources of fibre Fibre separation from wood (pulping) Whitening (bleaching) Recovered fibre Other raw materials Processing of fibre at the paper mill Manufacture on the paper or paperboard machine Finishing Packaging papers and paperboards Introduction Tissues Greaseproof Glassine Vegetable parchment Label paper Bag papers Sack kraft Impregnated papers Laminating papers Solid bleached board (SBB) Solid unbleached board (SUB) Folding boxboard (FBB) White lined chipboard (WLC) Packaging requirements Technical requirements of paper and paperboard for packaging Requirements of appearance and performance Appearance properties Colour Surface smoothness Surface structure 30

7 vi CONTENTS Gloss Opacity Printability and varnishability Surface strength Ink and varnish absorption and drying Surface ph Surface tension Rub resistance Surface cleanliness Performance properties Introduction Basis weight (substance or grammage) Thickness (caliper) Moisture content Tensile strength Stretch or elongation Tearing resistance Burst resistance Stiffness Compression strength Creasability and foldability Ply bond (interlayer) strength Flatness and dimensional stability Porosity Water absorbency Gluability/Adhesion/Sealing Taint and odour neutrality Product safety Specifications and quality standards Conversion factors for substance (basis weight) and thickness measurements 49 References 49 2 Environmental and waste management issues 50 MARK J. KIRWAN 2.1 Introduction Sustainable development Forestry Environmental impact of manufacture and use of paper and paperboard Issues giving rise to environmental concern Energy Water Chemicals Transport 67

8 CONTENTS vii Manufacturing emissions to air, water and solid waste Emissions to air Emissions to water Solid waste residues in paper industry Used packaging in the environment Introduction Waste minimisation Waste management options Recovery Recycling Energy recovery Landfill Life cycle assessment Conclusion 79 References 82 3 Paper-based flexible packaging 84 MARK J. KIRWAN 3.1 Introduction Packaging needs which are met by paper-based flexible packaging Printing Provision of a sealing system Provision of barrier properties Introduction to barrier properties Barrier to moisture and moisture vapour Barrier to gases such as oxygen, carbon dioxide and nitrogen Barrier to oil, grease and fat Barrier to light Manufacture of paper-based flexible packaging Printing and varnishing Coating Solvent-based coatings Water-based coatings Coatings applied as 100% solids, including wax and PE Metallisation Hot melt coatings Cold seal coating for pack closure/sealing Lamination Lamination with water-based adhesives Dry bonding Extrusion lamination Lamination with wax 101

9 viii CONTENTS 3.4 Medical packaging Introduction to paper-based medical flexible packaging Sealing systems Typical paper-based medical packaging structures Packaging machinery used with paper-based flexible packaging Paper-based cap liners (wads) and diaphragms Pulpboard disc Induction sealed disc Tea and coffee packaging Sealing tapes 114 References 115 Websites Paper labels 116 MICHAEL FAIRLEY 4.1 Introduction Types of labels Glue-applied paper labels Glue-applied paper label substrates Label application Pressure-sensitive labels Self-adhesive label substrates Self-adhesive label application Linerless self-adhesive labels In-mould labels In-mould label substrates In-mould label application Plastic shrink-sleeve labels Shrink-sleeve label films Shrink-sleeve label applications Stretch-sleeve labels Stretch-sleeve label films Stretch-sleeve label application Wrap-around film labels Wrap-around label films Wrap-around film label application Other labelling techniques Label adhesives Adhesive types Hot-melt adhesives Water-based adhesives Solvent-based adhesives Curable adhesives Label adhesive performance Factors in the selection of labels 131

10 CONTENTS ix 4.5 Nature and function of labels Primary labels Secondary labels Logistics labels Special application or purpose labels Functional labels Recent developments Label printing and production Letterpress printing Flexography Lithography Gravure Screen process Hot foil blocking/stamping process Variable information printing, electronically originated Ion deposition Laser printing Direct thermal printing Thermal transfer printing Dot matrix printers Ink jet printers Digital printing Print finishing techniques Lacquering Bronzing Embossing Label finishing Introduction Straight cutting Die-cutting Handling and storage Label application, labelling and overprinting Introduction Glue-applied label applicators Self-adhesive label applicators Shrink-sleeve label applicators Stretch-sleeve label applicators In-mould label applicators Modular label applicators Label legislation, regulations and standards Acts of Parliament EC Regulations and Directives Standards Specifications, quality control and testing Introduction 157

11 x CONTENTS Testing methods for self-adhesive labels Peel adhesion test method Resistance to shear test method Quick-stick test methods Adhesive coat weight test method Testing methods for wet-glue labels Tear strength test method Water absorption capacity test method Caustic soda resistance test method Paper weight test method Bending stiffness test method Waste and environmental issues 159 Websites Paper bags 161 WELTON BIBBY & BARON LTD 5.1 Introduction Paper bags and the environment Types of paper bags and their uses Types of paper bag Flat and satchel Flat bags Satchel bags bags with side gussets Medical and hospital bags Strip window bags Self-opening satchel bags (SOS bags) SOS bags for pre-packing SOS bags for use at point of sale SOS carrier bags with or without handles SOS carrier bags for pre-packing SOS carriers for use at point of sale Types of paper used Kraft paper the basic grades Grease resistant and greaseproof papers Vacuum dust bag papers Paper for medical use and sterilisation bags Wet-strength kraft Recycled kraft Coated papers Laminations Speciality papers Weights of paper 169

12 CONTENTS xi 5.4 Principles of manufacture Glue-seal bags Flat and satchel bags Self-opening satchel bags (SOS bags) Heat-seal bags Printing on bag-making machines Additional processes on bag-making machines Punching Paper handles Lacquers and adhesives Metal strips Reinforcement strips Additional operations after bag making Performance testing Paper Paper bags Hospital bags Dust bags Paper bags for food use Physical strength Printing methods and inks Printing methods Flexographic printing, off-line Flexographic printing, in-line Photogravure Silkscreen Inks Conclusion Development of the paper bag industry The future 174 Reference Composite cans 175 CATHERINE ROMAINE 6.1 Introduction Composite can (container) Definition Manufacturing methods Convolute winding Spiral winding Linear draw Single wrap Historical background Early applications 180

13 xii CONTENTS 6.5 Applications today by market segmentation Designs available Shape Size Consumer preferences Clubstore/institutional Other features Opening/closing systems Top end closures Bottom end closures Materials and methods of construction The liner The paperboard body Labels Nitrogen flushing Printing and labeling options Introduction Flexographic Rotogravure Lithography (litho/offset) printing Labeling options Environment and waste management issues Introduction Local recycling considerations Future trends in design and application Introduction Sorbents Valved membrane end Resealable plastic overcap Glossary of composite can related terms 194 Reference 196 Further reading 196 Websites Fibre drums 197 FIBRESTAR DRUMS LTD 7.1 Introduction Raw material Production Sidewall Drum base Lid Performance Decoration, stacking and handling Waste management 207

14 CONTENTS xiii 7.7 Summary of the advantages of fibre drums Specifications and standards 207 Reference 207 Websites Multiwall paper sacks 208 THE ENVIRONMENTAL AND TECHNICAL ASSOCIATION FOR THE PAPER SACK INDUSTRY 8.1 Introduction Sack designs Types of sacks Open mouth sacks Valved sacks Valve design Valve designs for sewn sacks Valve designs for pasted sacks Sewn closures Single sewing or chain stitch Double sewing Sewn closure constructions Sack materials Sack body material Sack krafts Extensible sack krafts Coated sack krafts Laminated sack krafts Non-paper materials Special purpose sack krafts Summary of sack body materials Ancillary materials Sewing tapes Sewing threads Filler (filter) cords Plastic handles Adhesives Printing inks Slip-resistant agents Testing and test methods Sack materials Strength tests Other physical properties/tests Sack testing Quality of finished sacks Performance tests 229

15 xiv CONTENTS 8.5 Weighing, filling and closing systems Open mouth sacks Weighing Sack applicators Filling Summary of weighing equipment for open mouth sack filling Closing Valved sacks Applicators Weighing and filling Rotary packing system Output levels of valved sack systems Sack identification Sack flattening and shaping Baling systems Standards and manufacturing tolerances Standards Manufacturing tolerances Environmental position 246 Useful contacts 247 Websites Rigid boxes 249 MICHAEL JUKES 9.1 Overview Rigid box styles (design freedom) Markets for rigid boxes Materials Board and paper Adhesives Print Design principles Material preparation Construction Drawer box Conclusion 260 References 261 Websites Folding cartons 262 MARK J. KIRWAN 10.1 Introduction Paperboard used to make folding cartons 264

16 CONTENTS xv 10.3 Carton design Surface design Structural design Manufacture of folding cartons Printing Cutting and creasing Flatbed die Rotary die Creasing and folding Embossing Hot-foil stamping Gluing Specialist conversion operations Windowing Waxing Packaging operation Speed and efficiency Side seam glued cartons Erection of flat carton blanks Carton storage Runnability and packaging line efficiency Distribution and storage Point of sale, dispensing, etc Consumer use Conclusion 314 References 315 Further reading 315 Websites Corrugated fibreboard packaging 317 JOËL POUSTIS 11.1 Introduction Overview Types of corrugated fibreboard packaging Corrugated board definitions Structure Weight per unit area (grammage) and thickness (calliper) Strength properties Corrugated fibreboard manufacture Corrugated fibreboard functions Box stackability Pallet arrangements Intrinsic compression Lifetime and safety factors 344

17 xvi CONTENTS Containability and protection Cushion performance Drop protection Puncture protection Preservation of the hardness Boxboard packing line considerations Flatness of corrugated fibreboard Closure of corrugated cases Visual impact and appearance Flexographic printing Packaging for food contact Good manufacturing practice Corrugated fibreboard and recyclability 369 References 371 Websites Solid fibreboard packaging 373 MARK J. KIRWAN 12.1 Overview Pack design Applications Horticultural produce Meat and poultry Fish Beer (glass bottles and cans) Dairy products Footwear Laundry Engineering Export packaging Luxury packaging Slip sheets Partitions (divisions and fitments) Recycling boxes Materials Water and water vapour resistance Printing and conversion Printing Cutting and creasing Packaging operation Waste management Good manufacturing practice 384 Reference 385 Websites 385

18 CONTENTS xvii 13 Paperboard-based liquid packaging 386 MARK J. KIRWAN 13.1 Introduction Packaging materials Paperboard Barriers and heat sealing layers Printing and converting Reel-to-reel converting for reel-fed form, fill, seal packaging Reel-to-sheet converting for supplying printed carton blanks for packing Carton designs Gable top Pyramid shape Brick shape Pouch Wedge Multifaceted and curved designs Square cross section with round corners Round cross section Bottom profile for gable top carton Opening, reclosure and tamper evidence Aseptic processing Post-packaging sterilisation Transit packaging Applications Environmental issues Resource reduction Life cycle assessment Recovery and recycling Systems approach 412 References 412 Further reading 413 Websites Moulded pulp packaging 414 CHRIS HOGARTH 14.1 Introduction Applications Raw materials Production Product drying Printing and decoration Conclusion 422 Website 422 Index 423

19 Contributors ETAPS Michael Fairley Fibrestar Drums Ltd Christopher Hogarth Michael Jukes Mark J. Kirwan Joël Poustis Catherine Romaine Welton Bibby & Baron Ltd The Environmental and Technical Association for the Paper Sack Industry, 64 High Street, Kirkintilloch, Glasgow G66 1PR, UK Labels & Labelling Consultancy, Maple House, High Street, Potters Bar, Herts EN6 5BS, UK Redhouse Lane, Disley, Stockport, Cheshire SK12 2NW, UK Cullen Packaging, 10 Dawsholme Avenue, Dawsholme Industrial Estate, Glasgow G20 0TS, UK London Fancy Box Company, Poulton Close, Dover, Kent CT17 0XB, UK Consultant and Lecturer in Packaging Technology, London, UK Smurfit Worldwide Research (Europe), 351 Cours de la Libération, Talence, France Integrated Communication Consultants, 4 Running Springs Court, Greer SC 29650, USA (chapter commissioned by Sonoco, 1 North Second Street, Hartsville, SC 29550, USA) Station Road, Midsomer Norton, Radstock BA3 2BE, UK

20 Preface This book discusses all the main types of packaging based on paper and paperboard. It considers the raw materials and manufacture of paper and paperboard, and the basic properties and features on which packaging made from these materials depends for its appearance and performance. The manufacture of twelve types of paper- and paperboard-based packaging is described, together with their end-use applications and the packaging machinery involved. The importance of pack design is stressed, including how these materials offer packaging designers opportunities for imaginative and innovative design solutions. Authors have been drawn from major manufacturers of paper- and paperboardbased packaging in the UK, France and the USA. The editor has spent his career in technical roles in the manufacture, printing, conversion and use of packaging. Packaging represents the largest usage of paper and paperboard and therefore both influences and is influenced by the worldwide paper industry. Paper is based mainly on cellulose fibres derived from wood, which in turn is obtained from forestry. The paper industry is a major user of energy, and is therefore in the forefront of current environmental debates. This book discusses these issues and indicates how the industry stands in relation to the current requirement to be environmentally sound and the need to be sustainable in the long term. Other issues discussed are packaging reduction and the options for waste management. The book is directed at those joining companies which manufacture packaging grades of paper and paperboard, companies involved in the design, printing and production of packaging, and companies which manufacture inks, coatings, adhesives and packaging machinery. It will be essential reading for students of packaging technology. The 'packaging chain' comprises: Those responsible for sourcing and manufacturing packaging raw materials. Printers and manufacturers of packaging, including manufacturers of inks, adhesives, coatings of all kinds and the equipment required for printing and conversion. Packers of goods, for example within the food industry, including manufacturers of packaging machinery and those involved in distribution. The retail sector, supermarkets, high street shops, etc., together with the service sector, hospitals, catering, education, etc. The packaging chain creates a large number of supplier/customer interfaces, both between and within companies, which require knowledge and understanding. The papermaker needs to understand the needs of printing, conversion and use. Equally, those involved in printing conversion and use need to understand the

21 xx PREFACE technology and logistics of papermaking. Whatever your position within the packaging chain, it is important to be knowledgeable about the technologies both upstream and downstream from your position. Packaging technologists play a pivotal role in defining packaging needs and cooperating with other specialists to meet those needs in a cost-effective and environmentally sound way. They work with suppliers to keep abreast of innovations in the manufacture of materials and innovations in printing, conversion and use. They are aware of trends in distribution, retailing, point-of-sale/dispensing, consumer use, disposal options and all the societal and environmental issues relevant to packaging in general.

22 Acknowledgements My thanks go to the contributing authors and their companies. It is not easy these days to find time for such additional work, and their contributions are much appreciated. The text has been greatly enhanced by the diagrams kindly provided by a large number of organisations and by the advice and information that I have received from many individuals in packaging companies and organisations. In particular, I would like to acknowledge the help that I have received from the following: Iggesund Paperboard, The Institute of Packaging, the Confederation of European Paper Industries (CEPI), Pira International, Pro Carton, British Carton Association, Swedish Forest Industries Federation, PITA, Paper Federation of Great Britain, INCPEN, M-real, Stora Enso, Bobst SA, AMCOR (flexibles for food and healthcare packaging), Billerud Beetham (manufacturer of medical packaging paper, formerly Henry Cooke), Bill Inman (former Technical Manager at Henry Cooke), Alexir Packaging (folding cartons), Papermarc Merton Packaging, Kappa Packaging, Kappa Lokfast, Tetra Pak, Elopak, SIG Combibloc, Rose Forgrove, Marden Edwards, Robert Bosch Packaging Machinery, Rovema Packaging Machines, IMA (tea packaging machinery), Dieinfo, Bernal, Atlas, Michael Pfaff (re. rotary cutting and creasing), Diana Twede (School of Packaging, Michigan State University), Neil Robson (re. packaging issues in relation to the Developing World), National Starch and Chemical (adhesives), Sun Chemical (inks), Paramelt (coating and laminating waxes), Smith Anderson (recycling and packaging products), Interflex Group (wax/paper flexible packaging), John Wiley & Sons (publishers). This book would not have been attempted without the experience gained in my packaging career, for which I thank former colleagues, especially those with whom I have been in contact recently: Reed Medway Sacks, Bowater Packaging (carton, paper bag and flexible packaging manufacture), Cadbury Schweppes (foods packaging), Glaxo (ethical and proprietary pharmaceuticals packaging), Thames Group (paperboard manufacture) and, in particular, Iggesund Paperboard, who encouraged me to become involved in technical writing. I would like to thank Richard Slade (Findus and Cadbury Schweppes) for involving me in packaging development from the 1960s onwards; Dennis Hine, who led much of the investigative work on carton performance and packaging machine/packaging materials interactions at PIRA; and Richard Coles who involved me in lecturing on packaging technology at BSc and Institute of Packaging Diploma level at West Hertfordshire College.

23 xxii ACKNOWLEDGEMENTS I am indebted to Professor Frank Paine, whom I first met as a colleague in Bowater in the 1960s, for his cheerful support and encouragement during the writing, and for reading and commenting constructively on the drafts of the manuscript. He has nearly 60 years of international experience in packaging technology and a substantial involvement in authorship and editing. His practical advice and patience has been much appreciated. Mark J. Kirwan