PVC PLASTICS

Properties, Processing, and Applications

PVC PLASTICS Properties, Processing,

and Applications

W. V. TITOW M.Phil., Ph.D., C.Chem., F.R.S.C., F.P.R.I., C. Text., A. T.I.

ELSEVIER APPLIED SCIENCE LONDON and NEW YORK

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WITII 120 TABLES AND 149 ILLUSTRATIONS

© 1990 ELSEVIER SCIENCE PUBLISHERS LTD

British Library Cataloguing in Publication Data

Titow, W. V. (Witold Victor) 1926­PVC plastics.1. Polyvinyl chlorideI. Title668.4236

ISBN 1-85166-471-8

Library of Congress Cataloging in Publication Data

Titow, W.V.PVC plastics: properties, processing, and applications/W. V. Titow.p. em.Includes bibliographical references.ISBN 1-85166-471-81. Polyvinyl chloride. I. Title.

TPll80.V48T58 1990668.4'237-dc 20 89-71512

CIP

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herein.

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Preface

This book originated from my Publisher's request for anew, concise account of PVC plastics in terms of their nature, properties, process­ing, and applications. There is thus, inevitably, an extensive thematic overlap with my-still relatively recent-PVC Technology (4th edi­tion), and I have drawn liberally on that source for a substantial amount of relevant basic material. However, the present book is by no means merely an abridgement of the earlier one: whilst indeed considerably shorter, it is not only comparable in scope and general coverage of the subject, but also contains much new information. I have made a point of again strongly featuring the numerous standards relevant-and in many cases cardinal-to the testing and characterisa­tion of PVC materials and products, and to the evaluation of their properties and performance: these standards are an indispensable part of the technology of PVC plastics, and nobody concerned with any aspect of this complex subject should fail to recognise that fact.

It is ever a pleasure to express appreciation and thanks where they are due.

I am grateful to Dipl-Ing. H. E. Luben of Brabender OHG, Duisburg, FRG, not only for the up-to-date information he provided on Brabender equipment, but also most particularly for his exception­ally friendly, helpful attitude in all our contacts, and for the trouble he took to make some illustrations and figures available in the form convenient for direct reproduction. The courtesy of those other persons and/or companies to whom I am indebted for the photo­graphic illustrations is, in each case, acknowledged in the relevant caption.

Myoid friend and former colleague Mr David Mugridge, of the Yarsley Technical Centre, Redhill, UK, kindly obtained for me some

v

vi Preface

additional information I needed for Chapter 20. I am most grateful for this help.

My appreciative thanks go to Mrs Micky Kruger, who typed the manuscript and provided other secretarial assistance.

As on previous occasions, I have experienced-and much appreciated-the friendly, courteous cooperation of every member of the Publisher's team concerned with the preparation and production of the book.

W.V.T.

Contents

Preface. . . . . . . . . . . . . . . . . . . . . . . . .. v

Section I-Introductory

Chapter 1 ................. . General Introduction . . . . . . . . . . . . 1.1 Some Key Terms, Definitions, and Concepts

1.1.1 What is PVC? . . . . . ..... 1.1.2 The Nature and Make-Up of PVC Materials 1.1.3 Abbreviations and Symbols for Material Names

1.2 Material and Test Standards . . . . . . . . . . . . 1.3 Origins, Historical Development, and Present Position of

pvc .................... . 1.3.1 Early History . . . . . . . . . . . . . . .. 1.3.2 Present Position: (a) PVC as a major, highly

versatile thermoplastic; (b) some topical concerns­vinyl chloride as a health hazard; some PVC for­mulation constituents as potential health hazards; health hazards associated with combustion products of PVC; disposal of waste PVC products . . . .

1.3.3 The PVC Industry-Outline of General Structure References Bibliography

Chapter 2 ....................... . Constitution and Formulation of PVC Materials. . . . . . . 2.1 PVC Compositions (Compounds) and Their Formulation

vii

1

3 3 3 3 4 5 6

8 8

10 16 17 18

22 22 22

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2.1.1 General Features and Main Categories . . . .. 22 2.1.2 Constituents of PVC Compositions (Formulation

Components) . . . . . . . . . . . . . . . 24 2.2 The Basics of Formulating PVC Compositions . . . .. 25

2.2.1 General Considerations: (a) processing require­ments; (b) service requirements-food-contact and medical applications; outdoor applications; electrical insulation; (c) material and process cost economy 25

2.2.2 Selection of the Principal Individual Constituents of a PVC Composition: (a) PVC polymer; (b) heat stabilisers; (c) plasticisers; (d) lubricants; (e) poly­meric modifiers; (f) fillers; (g) colourants; (h) other components of PVC formulations ....... 27

2.2.3 Some Aids to Formulating: (a) computer-aided formulating; (b) 'desirability function' in plasticiser selection for pPVC formulations . . . . . . .. 35

2.2.4 Some Interactions and Mutual Effects of Principal Components of PVC Formulations: (a) compatibility effects; (b) synergism; ( c) other mutual effects .. 36

2.2.5 Side-Effects of Formulation Components: (a) 'sec-ondary functionality' effects; (b) undesirable side-effects. . . . . . . . . . . . . . . . . . .. 37

2.2.6 Examples of Basic Formulations: (a) pipes and tubing; (b) extruded profiles; (c) sheeting and film; (d) calendered PVC/asbestos flooring (tiles); (e) cable covering and insulation; (f) injection mould­ings; (g) blow-moulded bottles; (h) paste formula-tions . . . . . . . . . . . . . 38

2.3 Materials Cost of a Formulation . . . . 45 2.4 Compositional Analysis of PVC Materials 46 References . . . . . . . . . . . . . . . . 48

Section 2-Constituents of PVC Compositions

Chapter 3 ............. . PVC Polymers . . . . . . . . . . . 3.1 Homopolymers of Vinyl Chloride.

3.1.1 Chemical Structure and Molecular Weight.

51

53 53 53 53

Contents

3.1.2 Polymer Morphology and Some Related Properties 3.1.3 Production of PVC Polymers: (a) vinyl chloride

monomer (VC); (b) polymerisation processes­suspension polymerisation; mass (bulk) polymerisa­tion; emulsion polymerisation . . . . . . . . .

3.1.4 Physical Forms of PVC Polymers: (a) suspension polymer particles; (b) mass polymer particles; (c) emulsion polymer particles . . . . . . . . . .

3.1.5 Effects of Some Polymerisation Process Factors on Polymer Characteristics

3.2 Copolymers of Vinyl Chloride 3.2.1 Kinds and Applications 3.2.2 Production . . . . .

3.3 Commercial PVC Polymers . 3.3.1 Polymer Properties Cardinal to Processing and/or

Service: (a) chemical composition; (b) molecular weight (viscosity number; K value); (c) polymer particle characteristics; (d) quality (purity)

3.3.2 Characterisation and Designation of Commercial PVC Polymers. . . . . . . . . . . .

3.3.3 Some Commercial Sources and Materials 3.4 Chlorinated Polyvinyl Chloride (CPVC)

3.4.1 Origins and Production Methods 3.4.2 Chemical Structure ..... . 3.4.3 3.4.4 3.4.5

References

Material Properties. . . . . . Formulation and Processing of CPVC Compositions Commercial CPVC Compounds and Their Applica­tions

Chapter 4 ............... . Stabilisers . . . . . . . . . . . . . . 4.1 Degradation and Stabilisation of PVC.

4.1.1 General. . . . . . . . . . . 4.1.2 Thermal Degradation: (a) outward manifestations;

(b) chemical aspects-dehydrochlorination and col­our development; chemical basis of other property changes; vulnerable sites in the PVC polymer chain; (c) thermal degradation in melt processing and static

ix

59

61

67

73 73 73 78 78

78

81 90 90 90 95 96 97

99 99

102 102 102 102

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exposure to heat; (d) effects of polymer molecular weight, and some impurities and additives . 103

4.1.3 Photochemical Degradation 109 4.2 Purposes and Functions of Stabilisers in PVC 111 4.3 Heat Stabilisers . 112

4.3.1 General Classification of Heat Stabilisers 114 4.3.2 Lead Compounds 115 4.3.3 Organotin Stabilisers: (a) chemical nature and types;

(b) characteristics and applications; (c) mode of action. 119

4.3.4 Other Metal-Based Stabilisers: (a) nature, and some general applicational features; (b) antimony stabili-sers; (c) calcium stearate; (d) mixed-metal stabilisers-barium/ cadmium and barium/ cadmium/ zinc stabilisers; calcium/zinc stabilisers; other mixed-metal stabilisers; mode of action of mixed-metal stabilisers 124

4.3.5 Organic and Miscellaneous Stabilisers: (a) esters of aminocrotonic acid; (b) urea derivatives; (c) epoxy compounds; (d) organic phosphites; (e) other or-ganic stabilisers 135

4.3.6 Stabiliser /Lubricant Balance and Interactions 140 4.4 Antioxidants and Light Stabilisers 141

4.4.1 Antioxidants. 141 4.4.2 Light Stabilisers: (a) organic UV absorbers; (b)

inorganic (particulate) UV-screening agents; (c) free-radical scavengers; (d) chromophore quenchers; (e) some general features of the action of light stabilisers and antioxidants 143

4.5 Stabilisers in Single-Pack Additive Systems 149 4.6 Some Commercial Stabilisers . 151 4.7 Some General Effects of Stabilisers on Various Properties

of PVC Compositions . 151 4.8 Some Stabiliser-Related Problems 151

4.8.1 Sulphide Staining. 151 4.8.2 Plate-Out . 157

4.9 Testing and Evaluation of Stabilisation Effects 160 4.9.1 The Concept of Stability in Processing, Service, and

Tests. 160 4.9.2 Stability Testing: (a) heat-stability tests-dynamic

Contents xi

stability tests; static stability tests; (b) light-stability ~~. 1~

References 174

Chapter 5. 177 Plasticisers 177 5.1 General Definition and Nature of Plasticisers . 177 5.2 Plasticisation Mechanism, and some Relevant Features of

Plasticiser Structure. . . . . . . . . . . . 179 5.3 Main Outward Manifestations of Plasticisation . 182

5.3.1 Effects of the Level of Plasticisation 182 5.3.2 Stages of Plasticiser-Polymer Interaction 184 5.3.3 Ageing of Plasticised PVC after Processing 185

5.4 Principal Functional Parameters of Plasticiser Action 186 5.4.1 Compatibility and Miscibility: (a) the 11 value; (b)

solubility parameter 6; (c) clear-point temperature (solid-gel transition temperature); (d) interaction parameters: Flory-Huggins (X) and Bigg (a); (e) Api Po ratio; (f) loop and roll compatibility tests; (g) maximum-torque temperature (fusion point) in con-trolled mixing . . . . . . . . . . 186

5.4.2 Effectivity (Efficiency) of Plasticisers . . . . . 193 5.4.3 Permanence of Plasticisers. . . . . . . . . . 195

5.5 Plasticiser Types, Their Characteristics and Commercial Versions. . . . . . . . . . . . . . . . . . . . . 196 5.5.1 General Type Classification . . . . . . . . . 196 5.5.2 Plasticiser Nomenclature: Names, Synonyms, and

Abbreviations . . . . . . . . . . . . . . .. 198 5.5.3 Properties of Individual Plasticiser Types, and Their

Main Effects in PVC: (a) phthalate plasticisers­lower phthalates; general-purpose phthalates; linear phthalates; higher phthalates; miscellaneous phtha­lates; (b) phosphate plasticisers-triaryl phosphates; trialkyl phosphates; mixed alkyl aryl phosphates; halogenated alkyl phosphates; (c) trimellitate plas­ticisers; (d) aliphatic diester plasticisers; (e) polyme­ric plasticisers; (f) miscellaneous plasticisers-epoxy plasticisers; chlorinated paraffins and olefins; mono­esters; glycol and polyglycol esters; other mis-cellaneous plasticisers; hydrocarbon extenders . . . 201

xii Contents

5.5.4 Transport, Handling, and Storage of Plasticisers 223 5.5.5 Some Commercial Sources and Trade Names of

Plasticisers . . . . . . . . . . . . . . . . 224 5.6 Plasticiser-Inftuenced Properties of PVC. . . . . . . 224

5.6.1 Formulating Considerations-General Points. 224 5.6.2 Softness and Tensile Properties: (a) softness; (b)

tensile strength and elongation at break 230 5.6.3 Low-temperature Properties . 237 5.6.4 Electrical Properties . . . . . . . . 239 5.6.5 Flammability. . . . . . . . . . . . 239 5.6.6 Permanence Properties: (a) volatile loss-

automotive fogging; plasticisation of cable cover­ings; (b) extraction resistance; (c) migration resis-tance; (d) high-humidity compatibility .... 239

5.6.7 Stain Resistance . . . . . . . . . . . . . . 248 5.6.8 Resistance to Weathering and Photodegradation 249 5.6.9 Resistance to Biological Attack . . . . . .. 250

5.7 Toxicity and Health Aspects . . . . . . . . . . . . 250 5.7.1 Plasticisers in Food-Contact and Medical Applica-

tions . . . . . . . . . . . . . . 250 5.7.2 Plasticiser Handling and Processing. 251

5.8 Standards Relevant to Plasticisers . 255 References . . . . . . . . . . . . . . . . . 255

Chapter 6. . . . . . . . . . . . . . . . . . 258 Fillers . . . . . . . . . . . . . . . . . . . 258 6.1 Definition and General Functions of Fillers 258 6.2 Particulate Mineral Fillers . . . . . . . . 259

6.2.1 Silicates and Silicas: (a) clay; (b) asbestos; (c) talc; (d) other silicate fillers-wollastonite; mica; nephe-line syenite . . . . . . . . . . . . . . . .. 259

6.2.2 Alkaline-Earth Metal Sulphates; (a) barium sulph-ate; (b) anhydrous calcium sulphate ...... 265

6.2.3 Calcium Carbonate Fillers: (a) general: types and characteristics; (b) whiting; (c) ground limestone, marble, and calcite; (d) ground dolomite; (e) pre­cipitated calcium carbonates; (f) filler properties and selection criteria-maximum particle size; particle size distribution and mean particle size; dry bright­ness; refractive index (opacifying effect); oil (plas-

Contents xiii

ticiser) absorption; dispersion characteristics; cost; (g) applications, and some effects, of filler loading-flooring; plasticised compounds; rigid compounds 266

6.3 Functional Fillers. . . . . . . . . . . . . . . . .. 281 6.3.1 Reinforcing Fillers: (a) asbestos (chrysotile) fibres;

(b) miscellaneous inorganic microfibres; (c) glass fibres; (d) microspheres; (e) fine-particle calcium carbonate. . . . . . . . . . . . . . . . . 281

6.3.2 Flame-Retardant and Smoke-Suppressant Fillers 286 6.3.3 Miscellaneous Functional fillers: (a) carbon black;

(b) metal, or metallised particles and fibres; (c) wood flour; (d) cellulose fibres; (e) starch 286

6.4 Surface Treatments for Fillers . . . . . . . 288 6.4.1 Stearate Treatments . . . . . . . . 289 6.4.2 Treatment with Silane Coupling Agents 289 6.4.3 Organotitanate Treatments . . . . . 290 6.4.4 Proprietary and Miscellaneous Treatments. 290

6.5 Commercial Fillers 293 References . . . . . . . . . . . . . . . . . . . . 293

Chapter 7. . . . . . . . . . . . 294 Lubricants . . . . . . . . . . . 294 7.1 Functions, Nature, and Effects 294 7.2 Interaction and Co-action of Lubricants with Other PVC

Formulation Components . . . . . . . . . . . . .. 301 7.2.1 Lubricant/Stabiliser Effects: (a) stabilising effects of

lubricants-direct stabilising action; synergistic ac-tion with stabilisers; indirect stabilising action; (b) lubricant action of stabilisers. . . . . . . . . . . 301

7.2.2 Mutual Effects of Lubricants and Plasticisers: (a) primary plasticisers; (b) secondary plasticisers and extenders . . . . . . . . . . . . . . . . .. 303

7.2.3 Effects of Polymeric Modifiers: (a) impact modifiers; (b) processing aids . . . . . . 304

7.2.4 Effects of Fillers and Pigments . . . . . . . .. 304 7.3 Assessment of Lubricant Performance. . . . . . . .. 305

7.3.1 Test Methods: (a) sheet 'fluidity' test; (b) two-roll milling; (c) flow in the moulds and dies-flow in a spiral mould; flow in a Rossi-Peakes flow tester;

xiv Contents

flow in a piston plastometer; the ASTM capillary rheometer test; (d) tests using the Brabender Plasti­Corder-fusion test in a roller mixer attachment; processability test in a Brabender Extrusiograph with a rheometric head . . . . . . . .

7.3.2 Some Research Equipment and Methods 7.3.3 'Lubricant Value' ..... .

7.4 Some Effects of Incorrect Lubrication 7.5 Commercial Lubricants References . . . . . . . . . . . . . .

Chapter 8 ............ . Polymeric Modifiers . . . . . . . . 8.1 Nature and Functions-General 8.2 Processing Aids. . . . . . . . 8.3 Impact Modifiers . . . . . . .

8.3.1 Impact Resistance-Definition, Significance, and Measurement . . . . . . . . . . . . . . . .

8.3.2 The Impact Resistance of PVC ........ . 8.3.3 The Nature, Effects, and Applications of Polymeric

Impact Modifiers for PVC: (a) ABS modifiers; (b) MBS modifiers; (c) acrylic modifiers; (d) rubber­modified styrene/maleic anhydride copolymers; (e) nitrile rubbers (acrylonitrile/butadiene copolymers); (f) E/V AC modifiers; (g) chlorinated polyethylene (CPE); (h) polyurethane (PUR) elastomers

References

Chapter 9 ........... . MisceUaneous Additives . . . . . 9.1 Additives Active in Processing

9.1.1 Chemical Blowing Agents for PVC Foams. 9.1.2 Cell-Control Agents for PVC Foams .. 9.1.3 Minor Additives for PVC Pastes . . ...

9.2 Additives Incorporated for End-Use Properties .. " . 9.2.1 Colourants: (a) general; (b) choice of colourant­

colour; processability; stability and performance in service; health and safety considerations; (c) some

305 309 309 310 310 312

313 313 313 314 316

316 322

323 333

335 335 335 335 343 344 345

9.2.2 9.2.3

9.2.4 9.2.5

References

Contents

practical tests-heat stability; stability to light and weathering; colour migration . . . . . . . . . Flame Retardants and Smoke Suppressants . . . Additives for Antistatic and Conductivity Effects: (a) antistatic surface-active agents; (b) polymeric antistatic additives; ( c) conductive fillers; (d) some relevant test methods and specifications . . . Odour Control Agents . . . . . . . . . . Matting ('Flatting') and Anti-blocking Agents

Section 3-Production (Compounding) of Solid PVC Composi-

xv

345 351

354 359 360 361

tions. . . . . . . . . . . . . . . . . . . . . . . . . . . 363

Chapter 10 ......... . Solid ('Dry') PVC Compositions 10.1 General ....... . 10.2 Types and Forms of PVC Compounds 10.3 Some Material Properties of PVC Compounds

10.3.1 Physical and Short-Term Mechanical Properties 10.3.2 Creep and Fatigue in Rigid Compositions: (a)

creep; (b) fatigue. . 10.3.3 Thermal Properties . 10.3.4 Electrical Properties 10.3.5 Chemical Properties 10.3.6 Miscellaneous Properties: (a) optical; (b) water

absorption; (c) others. . . . . . . . . . . . 10.4 Characterisation and Standard Designation of Commercial

PVC Compounds . . . 10.4.1 Characterisation 10.4.2 Designation

References .

Chapter 11 . . . . . . . . . . . . . . Compounding: Operations and Equipment 11.1 General . . . . . . . . . . . .

365 365 365 367 370 370

370 379 379 379

385

387 387 388 392

393 393 393

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11.2

11.3 11.4

Contents

Industrial Production of Solid Compounds . . . . . . . 396 11.2.1 Upstream Equipment and Operations: (a) han-

dling, storage, and conveying-polymer and fillers; plasticisers; other formulation components (additives); (b) metering-general; major for-mulation components; minor formulation com-ponents; control and accuracy in metering in­stallations; batch assembly. . . . . . . . . . . 396

11.2.2 Compounding Operations and Equipment: (a) general; (b) production of powder mixes-batch mixing; continuous mixing; (c) melt­compounding: objectives and general features; (d) melt-compounding machinery: continuous compounding-the Plastifikator (shear-cone com­pounder); the Buss kneader; the cascade ex­truder; the Kombiplast equipment; the FCM continuous mixer; the MPC/V compounder; the Bitruder BT; the planetary compounder; machine drives and controls; machine working surfaces and parts; on-line operational and melt quality con­trol; (e) further processing-pelletising; pellet cooling; mixing (blending) of pellets; final han­dling and delivery; (f) batch compounding in internal mixers; (g) compounding some recycled

materials ................. . 11.2.3 Compounding for Direct Feeding of Calenders. Compounding of Liquid PVC Compositions. . . . . . Small-Scale (Laboratory) Compounding ...... . 11.4.1 General: (a) usual objectives; (b) scope of discus-

412 455 455 455

sion in this chapter . . . . . . . . . . . . . . 455 11.4.2 Laboratory Compounding Equipment and Its

Uses: (a) some laboratory and pilot-scale counter­parts of industrial compounding equipment­powder mixers; two-roll mills; Kombiplast; Buss Kneader; compounding extruders; internal mixers; (b) specialised instrumented equipment for investigation and study of compounding be­haviour and effects

References . 456 463

Contents xvii

Section 4---Processing of Solid PVC Compositions into Products 465

Chapter 12 . . . . . . . . . . . . . . . . . . . . . . . . 467 Main Types of PVC Products and Methods of Their Production 467 12.1 PVC Products of Greatest Industrial Importance-General 467 12.2 Rigid PVC Products . . . . . . . . . . . . . . " 467

12.2.1 Pipes and Conduit: (a) types of PVC pipes-principal general kinds; some special pipe forms; (b) some formulation aspects; (c) important pipe properties and their determination . . . . . . . 467

12.2.2 Profiles and Cladding (Siding): (a) types and applications; (b) some formulation aspects; (c) testing and specifications . . . . . . . ., . 475

12.2.3 Sheeting and Film: (a) terminology; (b) produc-tion types; (c) some formulation aspects; (d) properties and applications

12.2.4 Blow Mouldings . . . 12.2.5 Injection Mouldings . 12.2.6 Gramophone Records.

12.3 Plasticised PVC Products ... 12.3.1 Electric Cable and Wire Coverings: (a) types and

applications; (b) properties and tests 12.3.2 Sheeting and Film . 12.3.3 Flooring. . . . . . 12.3.4 Tubing and Profiles. 12.3.5 Fabric Coatings

References

481 486 486 486 486

486 489 493 493 495 496

Chapter 13 . . . . . . . . . . . . . . . . . . . . . " 497 Extrusion. . . . . . . . . . . . . . . . . . . . . . .. 497 13.1 History and Significance of Extrusion in PVC Processing 497 13.2 Extruders Used in PVC Processing. . . . . . . . .. 498

13.2.1 General. . . . . . . . . . . . . . . . .. 498 13.2.2 Basic Operational Features: (a) the screw; (b) the

barrel; (c) the head and die assembly; (d) the hopper; (e) main operating characteristics of single-screw and twin-screw extruders for PVC processing. . . . . . . . . . . . . . . . . . 499

xviii Contents

13.3 Some General Points Relevant to PVC Extrusion 504 13.3.1 Working Surfaces 504 13.3.2 Use of Gear Pumps. 505 13.3.3 Purging. . . . . . 506 13.3.4 Coextrusion. . . . 507 13.3.5 Extrusion of CPVC . 507 13.3.6 Computerisation and Automation of Extrusion

Lines. . . . 508 13.4 Material Aspects. . . 508

13.4.1 Formulations 508 13.4.2 Feed Types . 508 13.4.3 Stock Transformations in the Course of Extrusion 509 13.4.4 Some Extruded-Product Faults: (a) manifestations

of incomplete gelation; (b) irregularities of par­ticulate appearance; (c) variation or fluctuation in dimensions; (d) plate-out . . . . . . . . 511

13.5 Basic Extrusion Lines for Important Extruded PVC Products . . . . . . . . . 513 13.5.1 Rigid Pipe Extrusion 513 13.5.2 Profile . . . . . 516 13.5.3 Sheeting and Film . 516 13.5.4 Wire Covering. . . 519

13.6 Some Commercial Extrusion Equipment 522 References . 522

Chapter 14 . 524 Calendering. 524 14.1 Origins, and Current Position in the PVC Industry 524 14.2 Equipment and Process: General Aspects. . . . 524

14.2.1 The Calender . . . . . . . . . . . . 525 14.2.2 The Calendering Operation: Main Features and

Their Effects on the Structure and Properties of Calendered Sheet . . . . . . . . . . . .. 529

14.3 Calender Lines . . . . . . . . . . . . . . . . .. 530 14.3.1 Regular General-Purpose Lines: (a) pre-calender

(compounding and feed) section; (b) calender section; (c) post-calender section-sheet take-off and stretching; embossing; cooling; measurement and control of sheet thickness; edge trimming; wind-up. . . . . . . . . . . . . . . . . . . 530

Contents

14.3.2 Other Lines and Arrangements: (a) lines for calendered flooring; (b) 'Calandrette' lines; (c)

xix

lamination on or at the calender . . . . . .. 542 14.4 Formulation of PVC Compositions for Calendering 546 14.5 Some Faults and Defects Occurring in Calendered Sheet-

ing. . . . . . . . . . . . . . . 549 14.5.1 Simple Dimensional Faults 549 14.5.2 Structural Defects . . . . 549 14.5.3 Faults Manifested in Appearance -. 550

14.6 Further Processing of Calendered Sheet 552 14.6.1 Press Finishing. . . 552 14.6.2 Press Lamination. . . . . . . 553 14.6.3 Surface Treatments. . . . . . 553 14.6.4 Continuous Lamination away from the Calender 553

14.7 Calendered-Sheet Products: Properties and Applications 554 References . . . . . . . . . . . . . . . . . . . . . .. 559

Chapter 15 . . . . . 560 Blow Moulding . . . 560 15.1 Basic Features. 560 15.2 Blow-Moulding Processes and Their Application to PVC 562

15.2.1 General Characterisation and Principal Features of Blow-Moulding Techniques and Systems: (a) extrusion blow moulding-general operational se­quence; parison programming, and other control; (b) injection blow moulding; (c) dip blow mould-ing . . . . . . . . . . . . . . . . . . .. 562

15.2.2 Stretch-Blowing in Blow Moulding. . . . .. 569 15.2.3 Process and Equipment Arrangements in Blow

Moulding . . . . . . . . . . . . . . . .. 570 15.2.4 Cooling Methods. . . . . . . . . . . . .. 571 15.2.5 Miscellaneous Features: (a) mould venting; (b)

removal of waste material; (c) part removal (take-off) systems; (d) blowing pressures 573

15.3 Industrial Blow Moulding of PVC . . 574 15.4 PVC Compositions for Blow Moulding 577

15.4.1 The Processing Aspect . . . 577 15.4.2 The End-Use Aspect . . . . 579 15.4.3 Formulations: (a) commercial compounds;

xx Contents

(b) formulation components-PVC polymer; sta­biliser system; impact modifiers; lubrication; other components .

15.5 PVC Blow Mouldings . . . 15.5.1 Applications .... 15.5.2 Properties and Tests

References .

Chapter 16 ................... . Injection Moulding . . . . . . . . . . . . . . . . 16.1 The Process and its Application to PVC-General 16.2 The Material Aspect . . . . . . . . . . . . .

16.2.1 PVC Melt Properties and Behaviour .. 16.2.2 Moulding Compounds: (a) general points; (b)

'easy flow' moulding compounds; (c) melt flow tests for moulding compounds . . . . . . . .

16.3 Equipment and Process Considerations ....... . 16.3.1 Equipment: (a) features and operation; (b) work­

ing surfaces . . . . . . . . . . . . . . . . 16.3.2 Processing: (a) stock temperature, and tempera­

ture settings; (b) rate of injection and injection pressure; (c) interaction of PVC with acetal polymers and copolymers . . . . . . . . . .

16.3.3 Flow Moulding. . . . . . . . . . . . . . . 16.3.4 Moulding Quality Maintenance, and Some Com-

mon Faults ............... . 16.4 Some Effects of Processing on the Morphology of Injec­

tion Mouldings . . . . . . . . . . . . 16.4.1 Quenching Stresses. . . . . . . 16.4.2 Orientation and Related Features

16.5 Injection Moulding of CPVC References . . . . . . . . . . . . . . . . .

Chapter 17 ........... . Other Processes. . . . . . . . . . 17.1 Compression Moulding of PVC

17.1.1 General ...... . 17.1.2 Industrial Applications: (a) production of gramo-

580 583 583 584 586

588 588 588 589 589

591 594

594

597 600

600

601 603 603 604 605

607 607 607 607

Contents xxi

phone records; (b) compression moulding of thick sheets (press lamination) 607

17.1.3 Sheet Moulding for Samples and Test Specimens: (a) unplasticised PVC sheet-preparation of mill sheet; compression moulding of final sheet in a picture-frame mould; (b) plasticised PVC sheet 610

17.1.4 Compression Moulding of PVC Paste 613 17.2 Thermoforming 614

17.2.1 General Features . 614 17.2.2 Plastics Materials Used in Thermoforming . 615 17.2.3 Assessment of the Thermoforming Characteristics

of Materials . 616 17.2.4 Thermoforming Methods: (a) main types and

variants; (b) some processing considerations . 619 17.2.5 Thermoforming Equipment: (a) machinery; (b)

moulds-mould materials; applicational features of main mould types; mould construction 627

17.2.6 Finishing Operations 630 17.2.7 Thermoformed Parts: (a) general design con-

siderations; (b) dimensional stability, and effects of temperature and draw ratio on part quality 630

17.3 Powder Sintering and 'Lost Filler' Methods in the Produc-tion of Porous PVC Sheets 632 17.3.1 Sintering of Powder 632 17.3.2 The 'Lost Filler' Method 633

References . 634

Section 5---Liquid PVC Compositions: Nature, Preparation, Processing, and Applications . . . . . . . . . . . 635

Chapter 18 . . . . . . . . . . . . . . . . . . . . .. 637 PVC Pastes. . . . . . . . . . . . . . . . . . . . .. 637 18.1 The Nature and Terminology of PVC Pastes-General 637 18.2 The Role and Basics of Paste Rheology ...... 638

18.2.1 Viscosity of PVC Pastes: (a) features relevant to behaviour in processing; (b) basic modes of rheological behaviour: effects of shear rate, and of time under constant shear . . . . . . . . . . . 638

xxii Contents

18.2.2 Rheological Effects of the Polymer Component in a PVC Paste: (a) polymer particle content ('poly­mer fraction'); (b) polymer particle characteristics-particle size and size distribution; particle interactions. . . . . 643

18.3 Measurement of PVC Paste Viscosity ......... 645 18.4 Gelation/Fusion of PVC Pastes . . . . . . . . . . . . 646

18.4.1 General Features of the Transformation of a Paste into a pPVC Material. . . . . . . . . . 646

18.4.2 Polymer-Plasticiser Interactions during the Gelation/Fusion of a PVC paste . . . . . 647

18.4.3 Practical Determination of the Completeness of Fusion in Paste Products . . . . . 651

18.5 The Composition of PVC Pastes. . . . . . . . . .. 653 18.5.1 Paste Formulation-General Points. . . . .. 653 18.5.2 Components of PVC Pastes: (a) paste polymers;

(b) plasticisers; (c) stabilisers; (d) fillers; (e) additives modifying paste rheology-thickening agents; viscosity depressants; diluents; (f) mis-cellaneous additives. . . . . . . . . . .. 653

18.5.3 Pastes for Rigid Products: (a) organosols; (b) rigisols . . . . . . 659

18.6 Preparation of PVC Pastes . . . . . . . . . . . 661 18.6.1 Some General Points . . . . . . . . . . 661 18.6.2 Small-Scale (Laboratory) Paste Preparation 662 18.6.3 Industrial Production of Pastes. . . . . . 664

18.7 Application of PVC Pastes: Processes and Products 666 18.7.1 Moulding Processes: (a) rotational casting; (b)

slush moulding; (c) dip mOUlding. . . . .. 666 18.7.2 Coating of Objects and Articles: (a) dip coating­

hot-dip coating; cold-dip coating; (b) spray coat-

18.7.3

18.7.4 18.7.5

References .

ing .................. . Coating of Fabrics and Paper: (a) coating pro­cesses and methods; (b) quality and testing of paste-coated materials-some coating faults; test-ing .................. . Paste Casting . . . . . . . . . . . . . . Other Paste-Processing Methods of Minor Sig­nificance

668

670 678

681 681

Contents xxiii

Chapter 19 . . 683 Solutions. . . 683 19.1 General 683 19.2 Composition of PVC Solutions 683

19.2.1 The PVC Polymers: (a) homopolymers; (b) co-polymers and terpolymers. . . . . 684

19.2.2 Solvents and Diluents. . . . . . . 688 19.2.3 Other Constituents of PVC Solutions 689

19.3 Preparation of PVC Solutions 692 19.4 Applications 694 References . . . . . . . . . . . 697

Chapter 20 . . . . . . . . . . . . . . . . . 698 PVC Latices . . . . . . . . . . . . . . . . 698 20.1 The Nature and PVC Versions of a Latex 698

20.1.1 Definition and General Characteristics 698 20.1.2 Basic Processing Features 700

20.2 Types of PVC Latices . . . . 702 20.2.1 General. . . . . . . 702 20.2.2 Homopolymer Latices 703 20.2.3 Copolymer Latices . . 703

20.3 Commercial PVC Latices . . . 706 20.4 Formulation and Compounding of PVC Latices 706

20.4.1 General Considerations . . . . . . . 706 20.4.2 Constituents Controlling Latex Stability and Pro­

perties: (a) latex stabilisers (emulsifiers); (b) wetting agents; (c) thickeners; (d) anti-foaming (defoaming) agents; (e) pH-modifiers and buffers 707

20.4.3 Additives Incorporated for End-Product Pro­perties: (a) heat-stabilisers; (b) plasticisers; (c) fillers; (d) pigments; (e) miscellaneous additives­matting agents; anti-blocking agents; flame retar-dants; biostats . . . . 711

20.5 Applications of PVC Latices . . . . . . . . . .. 719 20.5.1 Typical Uses-General . . . . . . . . .. 719 20.5.2 Examples of Basic Formulations for Particular

Applications. . . . . . . . . . . . . 723 20.6 Some Standard Test Methods for Polymer Latices 725 References . . . . . . . . . . . . . . . . . . . . 725

xxiv Contents

Section 6----Post-production Processing of PVC Products . . . . 727

Chapter 21 . . . . . . . . . . . . . . . . . . . . . .. 729 Fabrication, Conversion and Related Processing of PVC Sheet and Parts. . . . . . . . . . . . . . . . . . . . 729 21.1 Fabrication and Related Operations-General . 729 21.2 Welding of PVC Products. 733

21.2.1 General. . . . . . . . . . . . 733 21.2.2 Hot-Gas Welding. . . . . . . . 734 21.2.3 Heated-Tool (Hot-Plate) Welding 735 21.2.4 Indirect Heated-Element Welding 737 21.2.5 Friction Welding: (a) spin welding; (b) vibration

welding . . . . . . . . 737 21.2.6 High-Frequency Welding . . . . . . . .. 738 21.2.7 Ultrasonic Welding. . . . . . . . . . .. 740

21.3 Bonding of PVC with Solvents, Solvent Cements, and Adhesives . . . . . . . . . . . . . . . . 741 21.3.1 Solvent and Solvent-Cement Bonding 741 21.3.2 Adhesive Bonding 745

21.4 Cutting and Machining 745 21.4.1 Cutting. . . . . 745 21.4.2 Machining. . . . 750

21.5 Manipulation and Conversion of PVC Film and Sheeting for Packaging 750

References . . . . . . . . . . . . . . . . . . . . . .. 750

Chapter 22 . . . . . . . . . . . . 752 External Treatments of PVC Products 752 22.1 Decorative Surface Treatments 752

22.1.1 Printing. . . . . 752 22.1.2 Heat Transfers. . . . 754 22.1.3 Hot Foil Stamping . . 755 22.1.4 Embossing: (a) general; (b) emobssing of foamed

sheet products-mechanical embossing; chemical embossing. . 756

22.2 Surface Marking. . . 759 22.3 Protective Treatments 759

22.3.1 Lacquering . 759

Contents

22.3.2 Other Protective Coatings. . . . . . . . . . 22.3.3 Film and Sheet Lamination . . . . . . . . .

22.4 Treatment with High-Energy Ionising Radiation (Irradia­tion for Cross-Linking) . . . . . . . . . . . . . . . 22.4.1 Effects of High-Energy Radiation on Essentially

Saturated, Linear Polymers . . . . . . . . . 22.4.2 Irradiation of PVC Products: (a) PVC composi­

tions for products cross-linkable by high-energy radiation; (b) property improvements in irradiated PVC products; (c) the irradiation treatment

References .

xxv

761 762

762

762

764 768

Section 7-Applications of PVC Products, and Some Important Application-Related Properties . . . . . . . . . . 769

Chapter 23 . . . . . . . . . . . . . . . . . . . 771 Miscellaneous PVC Products and Their Applications 771 23.1 Cellular PVC Products . . . . . . . . . . . 771 23.2 PVC Fibres and Fibre Products . . . . . . . 777 23.3 Laminates or Laminate-Like Products Involving PVC

Layers . . . . . . . . . . . . . 778 23.4 Sheet-Type Interior Wall Coverings 779 23.5 Powder Coatings and Mouldings. 779 23.6 Medical Applications. . . 781 23.7 Applications in Motor-Cars . . . 782 23.8 Footwear Applications . . . . . 783 23.9 Some Special, Unusual, or Minor Products and Applica-

tions . 783 References . . . . . . . . . . . . . . . . . . . . . .. 785

Chapter 24 . . . . . . . . . . . . . . . . . . . . . . . . 787 PVC Properties of Special Significance in Some Important Usage Contexts . . . . . . . . . . . . . . . . . 787 24.1 Mechanical and Related Properties ....... 787

24.1.1 Principal Mechanical Properties . . . . . 787 24.1.2 Environmental Stress Cracking and Crazing 788

24.2 Properties Relevant to Electrical Applications . . . 792

xxvi Contents

24.2.1 Electrical Properties 792 24.2.2 Other Relevant Properties . 793

24.3 Properties Relevant to Some Effects of the Environment in Service. 798 24.3.1 Properties for Outdoor Applications: (a) stability

to light (UV resistance); (b) resistance to weathering-definition of weathering; factors in-strumental in the weathering of PVC; manifesta-tions of weathering of PVC; ways of promoting weathering resistance of PVC; evaluation of the resistance of PVC to weathering 798

24.3.2 Behaviour at Low and High Temperatures: (a) low-temperature properties; (b) high-temperature effects-general; maximum 'safe' temperature for continuous service (in the absence of mechanical stress); heat ageing of flexible PVC; effects as-sociated with the thermal softening of PVC at elevated temperatures. 813

24.3.3 Resistance to Biological Attack: (a) microbiologi-cal attack (biodegradation); (b) attack by insects and rodents 819

24.4 Properties Relevant to Barrier and Protective Applications 821 24.4.1 Permeability . 821 24.4.2 Chemical Resistance 833

24.5 Health Hazard Aspects . 833 24.5.1 Vinyl Chloride Monomer 834 24.5.2 PVC Compositions and Their Regular Constitu-

ents. 835 24.5.3 Peripheral Hazards in Production, Processing, and

Bulk Conveyance. 836 24.6 Burning Behaviour, Flammability, and Combustion Pro-

ducts. 836 24.6.1 General Burning Mechanism. 837 24.6.2 Flammability of PVC. 838 24.6.3 Products Generated by Burning PVC: (a) chemi-

cal nature; (b) smoke emission. 840 24.6.4 Burning Tests: (a) small-scale laboratory tests; (b)

larger-scale tests . 842 24.6.5 Tests for Smoke Emission and Properties: (a)

smoke density; (b) acid index; (c) toxicity . 845

Contents

24.6.6 Some Relevant Publications References .

Appendix 1 ..................... . Some Material Properties of PVC Products and Compounds

Appendix 2 ...................... . Quantities and Units: The SI System: Unit Conversion Tables

Appendix 3 ..................... . Abbreviations (Letter Symbols) Used in This Book for Some Polymers, Their Derivative Plastics, and Certain Monomers

xxvii

847 847

851 851

864 864

877

877

Index .......................... 881