Technology of Polymer Packaging

Arabinda Ghosh Technology of Polymer Packaging

Arabinda Ghosh

Technology of Polymer Packaging

Hanser Publishers, Munich

Hanser Publications, Cincinnati

The Author: Prof. Dr.-Ing. Arabinda Ghosh, University for Applied Sciences, Stuttgart (HdM), Nobelstr. 10, 70569 Stuttgart, Germany

Distributed in North and South America by: Hanser Publications 6915 Valley Avenue, Cincinnati, Ohio 45244-3029, USA Fax: (513) 527-8801 Phone: (513) 527-8977 www.hanserpublications.com Distributed in all other countries by Carl Hanser Verlag Postfach 86 04 20, 81631 München, Germany Fax: +49 (89) 98 48 09 www.hanser-fachbuch.de The use of general descriptive names, trademarks, etc., in this publication, even if the former are not especially identified, is not to be taken as a sign that such names, as understood by the Trade Marks and Merchandise Marks Act, may accordingly be used freely by anyone. While the advice and information in this book are believed to be true and accurate at the date of going to press, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein. The final determination of the suitability of any information for the use contemplated for a given application remains the sole responsibility of the user.

Cataloging-in-Publication Data is on file with the Library of Congress

Bibliografische Information Der Deutschen Bibliothek Die Deutsche Bibliothek verzeichnet diese Publikation in der Deutschen Nationalbibliografie; detaillierte bibliografische Daten sind im Internet über abrufbar. All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying or by any information storage and retrieval system, without permission in writing from the publisher. © Carl Hanser Verlag, Munich 2015 Editor: Cheryl Hamilton Production Management: Jörg Strohbach Coverconcept: Marc Müller-Bremer, www.rebranding.de, München, Germany Coverdesign: Stephan Rönigk Printed and bound by Hubert & Co GmbH, Göttingen, Germany Printed in Germany ISBN: 978-1-56990-576-0 E-Book ISBN: 978-1-56990-577-7

In Memory of My parents and The legendary Professor Dr.-Ing. habil. h. c. Rudolf Heiss 1903–2009 (Director of the Fraunhofer Institute for Food and Packaging Technology, Munich 1936–1975)

Preface

Since the first production of polyethylene on a large scale by ICI (Imperial Chemical Industries) in the 1930s, polymer materials, or as they are simply called, plastics, have been inevitable as successful packaging materials. Plastics protect all kinds of products like food, pharmaceuticals, cosmetics, medical products, and other nonfoods against deterioration. Although the amount of tissue material such as paper, paper board, and corrugated board used for packaging is a bit higher than polymers, polymers are inevitable for primary packaging. They fulfill all of the legislative regulations worldwide for direct contact with the product, particularly with food. No other packaging material shows such a continuous and rapid development as does polymer packaging material. Scientists, experts, and technologists of the packaging sector are responsible for the development and application of tailor-made solutions. This book will contribute to the practical knowledge of specialists. Besides basic and applied knowledge on technology, a number of valuable suggestions on critical cases are given in this book. Finally, I hope this book will be a valuable help for the reader to solve technical problems and be a contribution to successful packaging development. Global Packaging Materials – a Breakdown Plastics Glass

PE – Film, BM, IM, Roto … PP – Film, TF, BM, IM, …

Metal

PS – TF, Sheets, …

Paper

PET – BM, Film, …

Others

PVC – Film, Sheet, …

Plastics Have the Highest Growth Rate among All Materials in the Packaging Sector

BM: blow molding, IM: injection molding, TF: thermoforming, Roto: roto molding Raj Datta, Haldia Petrochemicals, National Conference, IIP, Kolkata 2012

Acknowledgements

I want to express my acknowledgement to a number of people in the packaging industries of Germany, Switzerland, and Belgium for their valuable information and kind permission to publish relevant information or figures. For valuable information: Mrs. Elisabeth Mersteiner, RPC Kutenholz, Germany Dr. Alfred Koblischek, Alcan-Tscheulin, Germany Dr. Karl-Heinz Hausmann, DuPont, Switzerland Mr. Helmut Meyer, Reifenhauser, Germany Mr. Herbert Stotkiewitz, Bosch Packaging, Germany Mr. Harald Braun, Rovema, Germany Mr. Matthias Huter, Solvay, Germany Mr. Matthias Schraegle, Huhtamaki, Germany Mr. Peter Ludwig, EK-Pack, Germany Mr. Raj Datta, Haldia Petrochemicals, India Dr. Christof Herschbach, Windmoeller & Hoelscher, Germany Dr. Sven Fischer, Krones, Germany Dr. Georg Kinzelmann, Henkel, Germany For figures: Dr. Michael Roth, Battenfeld, Germany Mr. William Reay, Kuraray, Belgium Mr. Herbert Stotkiewitz, Bosch Packaging, Germany Mr. Matthias Huter, Solvay, Germany Otto Hofstetter AG, CH – Uznach, Switzerland

Contents

Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VII Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IX Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XI Abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XV 1 Basics of Polymer Packaging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Definition of Polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Manufacturing of Polymer Resins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.3 Classification of Plastics: Molecular Structure . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.4 Plastics Additives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.1 Usual Additives in the Packaging Sector . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.1.2 Light Stabilizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.1.3 PVC Stabilizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.1.4 Antiblock Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.1.5 Antifog Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.1.6 Nucleating Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.1.7 Lubricants as Processing Aids . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.1.8 Slip Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.1.9 Antistatic Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.1.10 Colorants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.1.11 Optical Brighteners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.1.12 Chemical Blowing Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.1.13 Antimicrobial Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4 5 5 5 6 6 6 6 6 7 7 7 8 8

1.5 Required Performance of Polymer Packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.6 Different Types of Polymers Used for Packaging . . . . . . . . . . . . . . . . . . . . . . . . 9 1.6.1 Polyurethanes as Adhesives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

XII 

 Contents

1.7 Short Description of Some Polymers for Packaging Applications . . . . . . . . . . 12 1.8 Major Polymers Used in Packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 1.8.1 Important Points for the Technologist . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2 Manufacturing of Polymer Packaging. . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.1 Extrusion of Resins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.1 Technology of Extrusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.2 Continuous Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.2.1 Manufacturing of Blown Film . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.2.2 Manufacturing of Cast Film . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.2.3 Collapsible Tubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.2.4 Flexible Films for Packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.3 Important Features for the Technologist . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.4 Discontinuous Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.4.1 Injection Molding (IM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.4.2 Injection Blow Molding (IBM) . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.4.3 Extrusion Blow Molding (EBM) . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.4.4 Stretch Blow Molding (SBM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.4.5 Different Types of PET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1.4.6 Thermoforming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

19 20 26 26 30 34 39 48 49 49 52 54 56 60 60

2.2 Sealing of Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.2 Principles of Heat Generation for Sealing of Packaging Materials . . . . 2.2.3 Technology of Sealing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.3.1 Direct Heating Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.3.2 Indirect Heating Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

71 73 74 75 77

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

3 Converting of Polymer Packaging (Composite Packaging). . . . . . . . . 83 3.1 Technology of Converting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.1 Modes of Converting Packaging Material . . . . . . . . . . . . . . . . . . . . . . . . 3.1.2 Technology of Coating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.2.1 Extrusion and Coextrusion Coating . . . . . . . . . . . . . . . . . . . . . . 3.1.2.2 Coating with Lacquer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.2.3 Coating with Polymer Dispersion . . . . . . . . . . . . . . . . . . . . . . . . 3.1.3 Technology of Lamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.3.1 Extrusion and Coextrusion Lamination . . . . . . . . . . . . . . . . . . . 3.1.3.2 Dry Lamination, Solvent Based . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.3.3 Dry Lamination, Solvent-Free Adhesive . . . . . . . . . . . . . . . . . . .

83 84 85 85 86 88 89 90 91 95

  XIII

3.1.3.4 Glue or Water-Based Lamination . . . . . . . . . . . . . . . . . . . . . . . . . 97 3.1.3.5 Wax or Hot-Melt Lamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 3.1.4 Important Features for the Technologist . . . . . . . . . . . . . . . . . . . . . . . . . 99 3.2 Vacuum Deposition of Ultrathin Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 3.2.1 Physical Vapor Deposition (PVD) Process . . . . . . . . . . . . . . . . . . . . . . . 101 3.2.2 Chemical Vapor Deposition (CVD) Process . . . . . . . . . . . . . . . . . . . . . . 102 3.3 Radiation Upgrading of Packaging Material . . . . . . . . . . . . . . . . . . . . . . . . . . 104 3.3.1 Effect of Radiation on Plastics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 3.4 Extended (Foamed) Packaging Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 3.4.1 Physical Foaming with Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 3.4.2 Chemical Nucleating Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 3.4.3 Foam Extrusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 3.4.4 Foam Injection Molding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 3.4.5 Foam Thermoforming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 3.5 Special Topics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 3.5.1 Sealing through Liquid and Dust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 3.5.2 Transverse Sealing of Side-Folded Pouches . . . . . . . . . . . . . . . . . . . . . . 109 3.5.3 Weak Points of a Collapsible Polymer Tube . . . . . . . . . . . . . . . . . . . . . . 111 3.5.4 Pinholes in Packs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 3.5.5 Complaint Management for New Technologists . . . . . . . . . . . . . . . . . . 113 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

Abbreviations

μm

micrometer

ABL

aluminum-barrier laminate

AC

alternating current

Adh

adhesive

AFA

antifog agents

Al

aluminum

Al2O3

aluminum oxide

AlO

aluminum monoxide

AlOx

mixture of AlO and Al2O3

Ba

barium

bar

unit for pressure (105 Pa)

BN

boron nitride

BOPA / BONy)

biaxial-oriented flexible nylon

BOPET

biaxial-oriented flexible PET

BOPP

biaxial-oriented flexible polypropylene

Ca

calcium

CBL

ceramic-barrier laminate

CH3

methyl group

Cl2

chlorine

CO2

carbon dioxide

COC

cycloolefin copolymer

Coex

coextrusion

COF

coefficient of friction

CPP

cast polypropylene

CVD

chemical vapor deposition

D

diameter

EAA

ethylene–acrylic acid copolymer

XVI 

 Abbreviations

EBA

ethylene–butyl acrylate copolymer

EB-Gun

electron beam gun

EBM

extrusion blow molding

EMA

ethylene–methyl acrylate copolymer

EMAA

ethylene–methacrylic acid copolymer

EPS

extended polystyrene

ESCR

environmental stress crack resistance

EVA

ethylene–vinyl acetate-copolymer

EVOH

ethylene–vinyl alcohol-copolymer

Fe2O3

iron oxide (ferric oxide)

H2O

water vapor / moisture

HALS

hindered amine light stabilizer

HCl

hydrochloric acid

HDPE

high density polyethylene

HDT

heat distortion temperature

HFFS

horizontal-form-fill-seal machine

HIPS

high impact polystyrene

HSL

heat seal lacquer

IBM

injection blow molding

IM

injection molding

IML

in-mold labeling

IR

infrared

K

potassium

LDPE

low density polyethylene

LLDPE

linear low density polyethylene

m/c

machine

MDPE

medium density polyethylene

mLLDPE

metallocene LLDPE

MXD6

meta-xylene diamine

N

nitrogen

Na

sodium

NaOH

sodium hydroxide

OPA / ONy

monoaxially oriented nylon

OPLA

mono- or biaxially oriented polylactic acid copolymers

OPS

oriented polystyrene

PA

polyamide / nylon

PAN

polyacrylonitrile

PBL

polymer barrier laminate



PE

polyethylene

PEN

polyethylene naphthalate

PET-A

amorphous polyester

PET-C

crystalline polyester

PET-G

glycol modified polyester (cyclohexanedimethanol)

PET

polyester / polyethylene terephthalate

PLA

polylactic acid

PO

polyolefin

PP

polypropylene

PS

polystyrene

PTFE

polytetrafluoroethylene

PTMT

polytetramethylene terephthalate

PU

polyurethane

PVC

polyvinyl chloride

PVC-P

plasticized polyvinyl chloride

PVC-U

unplasticized polyvinyl chloride

PVD

physical vapor deposition

PVdC

polyvinylidene chloride

PVOH

polyvinyl alcohol

RPM

revolutions per minute

SB

solvent based

SBM

stretch blow molding

SF

solvent free

SiO

silicon monoxide

SiO2

silicon dioxide

SiOx

mixture of SiO and SiO2

SPPF

solid phase pressure forming

SSE

single screw extruder

TE

melt temperature

TG

glass transition temperature

TiO2

titanium dioxide

TSE

twin screw extruder

ULDPE

ultra low density polyethylene

UV

ultraviolet

VAC

vinyl acetate

VFFS

vertical-form-fill-seal machine

VLDPE

very low density polyethylene

Zn

zinc

XVII