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`BOREALIS EXHIBIT 1071
`
`Page 1 of 6
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`BOREALIS EXHIBIT 1071
`
`

`
`Aberremy
`
`tased com~
`its course
`and future
`‘i011 Sh0U1d
`‘nd (0) the
`in an area
`
`at nearby
`611 Group
`esign and
`polyester
`entsfmm
`S are also
`which is
`
`Structural
`
`raph. The
`ma which
`
`ng.
`
`.
`Principles of 9
`Polymer Ertgmeermg
`
`Second edition
`
`N. G. Mccrum
`
`[1er/_/"orcl College
`Uniue sity of (bford
`
`C. P. Buckiey
`.
`_
`w
`Department of brtgtrzeermg Science
`University of Oxford
`
`C. B. Bucknall
`
`/ildmmced Materials Department
`Cranfield University
`
`OXFORD 0 NEW YORK 0 TOKYO
`OXFORD UNIVERSITY PRESS
`1997
`
`Page 2 of 6
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`

`
`d OX2 6DP
`Oxford University Press, Great Clarendon Street, Oxfor
`‘
`0rq‘ord New York
`Athens Auckland Bangkok Bogota Bombay Buenos Aires
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`and associated companies in
`1\
`Berlin Ibadan
`G v“ Unfiiersity Press “lip
`O)q‘ord is a trade mark
`Published in the Uri ecl\Stat"e:$"E_l;:
`by Oxford University
`ress Inc.,
`© N. G. MCCrum, C. P.
`fir
`First edition published 1988
`Reprinted I989, I990, J99], 1992, 1994, 1995, 1996
`Second edition 1997
`
`3
`
`,
`
`M ‘ _
`P58 55%
`I 9 Q ,7
`
`.
`
`. ucknall, 1997
`
`All right: reserved. No part of this publication may be
`reproduced, stored in a retrieval system, or transmitted, in any
`form or by any means, without the prior permission in writing of Oxford
`University Press. Within the UK exceptions are allowed in respect of any
`fair dealing for the purpose of research or private study, or criticism or
`review, as permitted under the Copyright, Designs and Patents Act, 1988, or
`in the case of reprographic reproduction in accordance with the terms of
`licences issued by the Copyright Licensing Agency. Enquiries concerning
`reproduction outside those terms and in other countries should be sent to
`the Rights Department, 0.g‘ord University Press, at the address above.
`
`This book is sold subject to the condition that it shall not,
`by way of trade or otherwise, be lent, re-sold, hired out, or otherwise
`circulated without the publis/1er’s prior consent in any form of binding
`or cover other than that in which it is published and without a similar
`condition including this condition being imposed
`on the subsequent purchaser.
`
`A catalogue record for this book is available from the British Library
`
`Library of Congress Cataloging in Publication Data
`McCrum, N. G.
`Principles ofpolymer engineering / N.G. McCrum, C.I’. Buckley,
`C.B. Bucknall. - 2nd ed.
`Includes bibliographical references and index.
`ISBN 0 19 856527 5 (Hbk).
`ISBN 0 19 856526 7 (Pbk)
`1. Polymers.
`2. Polymerization.
`1. Buckley, C. P.
`II. Bucknall, C. B.
`111. Title.
`TA455.P58M334 I997
`668.9—dc2l
`ISBN 0 19 856527 5
`(Hbk)
`ISBN 0 19 856526 7
`(Pbk)
`
`97-12589
`
`Typeset by Technical Typesetting Ireland
`Printed in Great Britain by Bookcrafi Ltd, Midsomer Norton, Avon
`
`Page 3 of 6
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`

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`8.4 Designing for stiffness
`
`389
`
`ung’s modulus. An incorrect interference can result on the one
`E is Y0
`cracking of the part, and on the other in loosening of the joint.
`hand 1“
`laxation in the polymer and differences in thermal expansion
`stress Te
`Coefficient must both be taken into account. Knurled metal surfaces
`enabie the polymer to creep into depressions and increase joint strength.
`8 33 Thermosetting polymers
`Manufacture of components from thermosetting resins or from rubbers
`involves not only shaping the material, but also carrying out an exothermic
`Chemical reaction. Proper control of temperature is required in order to
`obtain an acceptable rate of reaction without overheating and causing
`unwanted reactions which lead to thermal runaway. It may therefore be
`necessary to restrict thicknesses. The choice of curing formulation is also
`important, and where solid curing agents are used, as in epoxy resins, the
`state of subdivision of the crystals can be critical. Significant shrinkage
`occurs during curing of resins, and must be allowed for in mould design.
`Constrained shrinkage can cause void formation and internal stress.
`Differential shrinkage causes surface irregularities in fibre composites,
`where the fibres restrict contraction locally. Special ‘1ow—profile’ additives
`have been developed for use in polyester resins to combat this problem in
`applications that demand high—quality surfaces (notably in the car industry).
`The other major problem in the manufacture of components from compos-
`ites is to minimize defects, including broken, kinked, misaligned, or incom-
`pletely wetted fibres, resin-rich areas, voids, or dust contamination. This is
`mainly a question of production engineering, with an emphasis upon
`quality control. Fibre orientation in laminates can be predetermined with
`some precision by means of tape-laying or filament-winding machines,
`but some care is needed to avoid gaps on the one hand and overlap
`on the other.
`
`8.4 Designing for _stiffness
`8.4.1 Plastics
`Standard tests for the stiffness of plastics are based on either tensile or
`flexural measurements. The tensile test has the advantages that the stress
`is uniform in the gauge length, and that the corresponding strains can be
`measured directly. On the other hand, the three—point bending test illus-
`trated in Figure 8.12 can be carried out with very simple apparatus.
`Young’s modulus is calculated by applying the standard equations for a
`beam undergoing small elastic deflections:
`UP
`E : 4bd3A'
`
`(8.2)
`
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`390
`
`8.12 The three-point bending test.
`
`The maximum stress occurs at the midspan, in the outer fibres, and is
`given by
`
`3PL
`
`0'
`W: 21142‘
`
`(8.3)
`
`The maximum shear stress occurs in the neutral plane at the centre of the
`bar:
`
`3P
`1'
`max = W
`
`These equations hold for small deflections, when the polymer is linearly
`viscoelastic.
`Values of modulus determined in tension or flexure at one or more
`
`temperatures are provided in tables of data supplied by manufacturers.
`Whilst these single-point data are useful for materials selection, they are
`obviously inadequate for detailed design of load—bearing components. Here
`the engineer must look for information about time-dependence, which is
`usually obtained from tensile creep measurements. Most manufacturers’
`handbooks contain sets of creep curves obtained over a range of applied
`stresses,
`for
`strains up to about 0.03, as
`shown in Figure 8.13;
`some handbooks also include creep curves for one or more elevated
`temperatures.
`For ease of reference, the creep data are usually replotted in one 01‘
`more different ways, as illustrated in Figures 8.14(a) and (b). IS0ChT0“°“5
`stress-strain curves (Figure 8.14(a)), which are discussed in Chapter 4, are
`included in most discussions of creep characteristics. From isochronous
`curves of this type, the engineer can determine the secant modulus of the
`polymer at any given strain or applied stress and time under load. T1115
`creep modulus E(o‘,t) is simply the reciprocal of the apparent creep
`compliance at the appropriate stress and time: o-/.=:(tT, 0- Another Come‘
`nient way to present creep data is in the form of isometric curves, as show:
`in Figure 8.14(b), which are helpful in designing plastic C0mP°“emS to
`
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